BIOIGSY

BIOLOGY
LIBRARY

FRONTISPIECE, i, cell of fleshy scale of bulb of onion (Allium Cepa) showing cyto-
plasm, nucleus and large central vacuole.

Chloroplasts: 2, a parenchyma cell of green fruit of garden pepper (Capsicum annuum)
showing cytoplasm, nucleus and chloroplasts; 2a, a chloroplast of a moss (Funaria) showing
green granules, assimilation starch grains and protein granules; 2b, a cell near the periphery
of the pseudo-bulb of the orchid (Phaius grandifolius) showing cytoplasm and three reserve
starch grains formed by leucoplasts, which latter under the influence of light have developed
into chloroplasts.

Chromoplasts: 3, a parenchyma cell of ripe fruit of Capsicum annuum showing cyto-
plasm, nucleus and yellowish-red chromoplasts; 3a, isolated chromoplasts of carrot (Daucus
Car ota).

4, transverse section of petal of wild pansy (Viola tricolor) showing colored cell-sap in
epidermal cells.

APPLIED AND ECONOMIC

BOTANY

ESPECIALLY ADAPTED FOR THE USE OF STUDENTS IN
TECHNICAL SCHOOLS, AGRICULTURAL, PHARMACEU-
TICAL AND MEDICAL COLLEGES, AND ALSO AS A BOOK
OF REFERENCE FOR CHEMISTS, FOOD ANALYSTS
AND STUDENTS ENGAGED IN THE MORPHOLOGI-
CAL AND PHYSIOLOGICAL STUDY OF PLANTS

BY

HENRY KRAEMER, Ph.B. (in Chemistry), Ph.M.
(in Pharmacy), Ph.D. (in Botany).

PROFESSOR OF BOTANY AND PHARMACOGNOSY, AND DIRECTOR OF THE MICROSCOPICAL LABORA-
TORY IN THE PHILADELPHIA COLLEGE OF PHARMACY; MEMBER OF THE EXECUTIVE COM-
MITTEE OF REVISION OF THE PHARMACOPOEIA OF THE UNITED STATES OF AMERICA;
CORRESPONDING MEMBER OF THE SOCIETE DE PHARMACIE DE PARIS, ETC.

ILLUSTRATED

With 424 plates, comprising about 2000 figures

PUBLISHED BY THE AUTHOR

145 NORTH TENTH ST.,

PHILADELPHIA

COPYRIGHT, 1914, BY HENRY KRAEMER

ALL RIGHTS RESERVED

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BIOLOGY

MBRARY

G

PREFACE.

THERE are quite a number of books on botany, many of which serve
a very excellent purpose. For the most part, however, they are not adapted
for the use of students in the applied sciences where the knowledge of
botany is to be utilized later in practical work. It is now more than sixty
years since Schleiden showed the value of the microscope in the examina-
tion of drugs and Schacht demonstrated its usefulness in the study of
textile fibers. Since that time quite a number of works have been pub-
lished dealing with the microscopy of special technical products, as drugs,
foods, fibers, woods, etc., but there have been no text-books which could
be employed in the courses on applied and economic botany that would
satisfy either the desires of the student or fit the graduate for practical work
in commercial life. It is not generally appreciated that there is a depart-
ment of applied botany which is distinct from every other phase of botani-
cal study ; the point of view and the technique being peculiarly its own and
the problems so intricate and important that they should ever be held be-
fore the student and command his constant attention. It is almost self-
evident that courses in botany which are intended for intellectual culture
or scientific discipline are not adapted for technical courses of instruction.
In the latter the student has a right to ask for the application of the in-
struction which he is receiving and to show an interest in proportion as the
instructor is able to demonstrate its value. There are some who consider
that a more or less superficial knowledge of botanical principles and micro-
scopic technique is sufficient for the student in applied or economic botany.
On the contrary, we find that a rather extended knowledge of botany and
a very thorough preparation in certain phases of botanical work are
absolutely required in order to prepare him to meet and solve the many
problems that arise in the commercial world. Many of the commercial
problems that are held to be chemical and which are handed to the chem-
ist for solution are, as a matter of fact, of a botanical character and can
be solved with less expense and less time by the trained botanist. What
is really needed is the trained analyst, who, while proficient with chemical
methods, is also thoroughly versed in microscopic technique. We have
come to a time, if real progress is to be made both in the manufacture of
plant materials and in the examination of commercial substances, that it
is necessary to bring both chemical and botanical training and knowledge
to bear upon the problems involved.

Nearly all of the problems upon which one is liable to be consulted in
active practice, whether they involve new processes of manufacture or
the examination of the finished market material, show at the outset that
the analyst must have a very thorough knowledge of the cell constituents
and the tissues composing the raw material. It is for this reason that
almost one-half of the material of this volume is devoted to the study of

iv PREFACE.

cell-contents, forms of cells, and the outer and inner morphology of higher
plants. The facts and illustrations here presented cover not only the latest
researches on their morphology, origin, and distribution, but also the
most recent advances in regard to their chemical nature. A fair amount
of this work is original, and the presentation in one volume, it is hoped,
will be appreciated in addition also by students of the plant cell as well
as the phyto-chemist.

In the practical examination of the crude materials of the market we
find more or less contamination with fungi, lichens, and other lower plants,
and for this reason, as well as for the understanding of the morphology of
the higher plants, a more or less succinct treatment of the Principal Groups
of Plants is given in Chapter I. Another reason which has prompted the
author to lay considerable stress on the knowledge contained in this chap-
ter is that if the student will master the technique and will apply himself
to this part of the work, he will be better prepared to take up the study
of the structures of higher plants.

The chapter on Classification of Higher Plants is quite extended and
illustrated with a large number of photographs, showing not only many
of our interesting wild plants but the principal economic plants that are
used as foods, drugs, and for other economic purposes, with considerable
valuable technical information concerning them. The chapter on Nomen-
clature has been included in order that the derivations of botanical names
might be better understood and their correct spelling facilitated. The
chapter on Cultivation of Medicinal Plants, while especially prepared for
those interested in the subject, will be found useful to those interested in
other industries where the extermination of native plants is calling attention
to practical means for their replenishment. The chapter on Microscopic
Technique contains methods for the preparation of commercial materials
and much information that doubtless will facilitate practical work. The
index contains some 6,000 titles, making the information contained in this
volume readily accessible.

The work is illustrated throughout, and the legends accompanying the
illustrations will be found interesting and instructive and in most instances
supplement the information given in the text. All of the illustrations which
are not reproductions of photographs and drawings made by the author
are duly credited. The author acknowledges the valuable services rendered
by his associates in the preparation of the text, reading of proof, and prep-
aration of the index; to Professor Wallace Truesdell for assistance in
the chapter on Botanical Nomenclature and to Mr. Stewardson Brown for
the use of a number of photographs. When larger monographs and
authoritative works have been consulted, due credit has been given in the
text, so that the present work is a foundation not only of a text-book for
students of applied and economic botany but as a reference book for manu-
facturers and analysts.

NOVEMBER, 1014. H. K.

CONTENTS.

CHAPTER I.— PRINCIPAL GROUPS OF PLANTS.

PAGE

INTRODUCTORY i

THALLOPHYTES 5

Schizophy tes 7

Schizophyceae (Fission Algae) 3

Schizomycetes (Bacteria) I2

Algae I6

Chlorophyceae (Green Algae) 20

Phaeophyceae (Brown Algae) 28

Rhodophyceae (Red Algae) 31

Diatoms 35

Fungi 40

Phycomycetes (Alga-like Fungi) 42

Ascomycetes (Including Yeasts) 47

Basidiomycetes 56

Fungi Imperfecti 70

Lichens 71

ARCHEGONIATES 75

Bryophytes 76

Hepaticae (Liverworts) 80

Musci (Mosses) 84

Pteridophytes ; . 86

Filicales (Ferns) 87

Equisetales (Horsetails) . ." 96

Lycopodiales (Club Mosses) 97

SPERMOPHYTES (SEED PLANTS) 100

Gymnosperms 101

Angiosperms 119

ORGANIC EVOLUTION 128

CHAPTER IL— CELL-CONTENTS AND FORMS OF CELLS..

PROTOPLASMIC CELL-CONTENTS 134

NON-PROTOPLASMIC CELL-CONTENTS 140

FACTORS INFLUENCING GROWTH, INCLUDING FOOD OF PLANTS 246

FORMS OF CELLS 262

Parenchyma 262

Mechanical Tissue 264

Conducting or Mestome Cells 272

Protecting Cells 277

v

vi CONTENTS.

CHAPTER III.— OUTER AND INNER MORPHOLOGY OF THE

HIGHER PLANTS.

INTRODUCTORY 298

I. Outer Morphology .of the Root 299

Inner Structure of the Root 309

II. Outer Morphology of the Stem 320

Inner Structure of the Stem 338

III. Outer Morphology of the Leaf 348

Inner Structure of the Leaf 365

IV. Outer Morphology of the Flower 374

Inner Structure (Histology) of the Flower 402

V. Outer Morphology of the Fruit 408

Inner Structure of the Fruit 42-1

VI. Outer Morphology of the Seed ... v. 423

Inner Structure of the Seed , 427

CHAPTER IV.— BOTANICAL NOMENCLATURE 430

CHAPTER V.— CLASSIFICATION OF ANGIOSPERMS YIELDING
ECONOMIC PRODUCTS.

INTRODUCTORY 463

MONOCOTYLEDONS 463

DICOTYLEDONS 501

Archichlamydeas or Choripetalae 504

Metachlamydese or Sympetalae , 643

CHAPTER VI.— CULTIVATION OF MEDICINAL PLANTS

PLANTS GROWN FROM SEEDS .• 728

PROPAGATION BY CUTTING 733

COLLECTING AND DRYING OF DRUGS 737

RELATIVE VALUE OF DRUGS FROM CULTIVATED AND WILD PLANTS .... 739
PROGRESS IN THE UNITED STATES 744

CHAPTER VII.— MICROSCOPIC TECHNIQUE AND REAGENTS.

MAKING OF SECTIONS 749

PRACTICAL SUGGESTIONS 751

MlCROMETRY OR MICROSCOPIC MEASUREMENT 754

REAGENTS 755

EFFECTS OF IMPORTANT MICRO-CHEMICAL REAGENTS 759

THE MICRO-POLARISCOPE 764

THE SPECTROSCOPE IN MICROSCOPIC ANALYTICAL WORK 764

DARK FIELD ILLUMINATION AND THE ULTRA-MICROSCOPE 765

MICRO-ANALYSIS 766

BOTANY

CHAPTER I
PRINCIPAL GROUPS OF PLANTS

INTRODUCTORY

THERE are four main lines of botanical work now recognized,
— namely, Morphology, Histology, Physiology, and Ecology.
MORPHOLOGY treats of the form and structure of plants and the
subject is sometimes divided into (i) external morphology or
organography and (2) internal morphology or anatomy (histol-
ogy). The former deals with external characters of plant parts and
the latter with their minute inner structure. PHYSIOLOGY may be
defined as the study which considers life processes and the condi-
tions which influence these. ECOLOGY is the study of the adapta-
tion of plants and their parts to external conditions. It is impor-
tant to bear in mind, however, that these several departments
are more or less interdependent, and that one of them cannot be
intelligently studied without a consideration of the problems of
the others. For instance, as Goebel states, we cannot under-
stand the relation of the external forms of organs without refer-
ence to their functions. In other words, form and function have
a direct relation ; one influences the other. So, too, in the study
of ecology we study the influence of external conditions on
plants and these, as indicated above, have a direct influence on
physiological processes, and thus the study of ecology merges
into the study of physiology on the one hand and into morphology
on the other.

While this book will deal chiefly with the structure of plants
and their parts, still it will be necessary occasionally to refer to
some of the characters of plants which properly belong to other
departments of botanical study.

> Basis of Plant Structure. — In order to understand the sig-
nificance and relation of the various parts of plants it is necessary

i

2 A TEXT-BOOK OF BOTANY.

to know something of their functions and habits of life as well
as of their internal structure. It is desirable at this point to give a
brief consideration to the cell, as it is the unit of plant structure.

If we make a section of a plant and examine it by means of
the microscope, the cut surface presents the appearance of a
network, indicating that the tissue is made up of small compart-
ments or chambers. One of these compartments together with
its contents constitutes the structure known as the CELL (see
Frontispiece).

The cell-contents vary greatly in appearance and composi-
tion, but in all active or living cells there is always present the
substance known as PROTOPLASM. The protoplasm is the basis
of all plant structures whether they belong to the lowest or high-
est forms ; for by its aid or from it all parts of the plant are
developed. Even the cell-wall is a product of protoplasmic activity.
The protoplasmic content of the cell consists of several intimately
related but more or less distinct portions, — namely, a somewhat
thin, semi-liquid, granular portion known as the CYTOPLASM ;
a more or less spherical body embedded in the cytoplasm called
the NUCLEUS ; and frequently, but not always, certain small
bodies which are more or less variable in shape called PLASTIDS,
these being also embedded in the cytoplasm (see Frontispiece).
The cytoplasm and nucleus are sometimes considered together
as a unit, which is known as the PROTOPLAST. A fuller discussion
of the differentiated portions of the protoplasm will be found in
Chapter II.

The lowest organisms, as the slime molds, do not have an
enclosing membrane, but consist of a naked mass of protoplasm.
With this exception plants have an outer wall or membrane.
They may consist of a single cell, as in the Bacteria, or a chain
of cells, as in the filamentous Algae, or a mass of cells, as in the
majority of plants, and are accordingly designated as unicellular
or multicellular. The cell-wall is composed for the most part
of cellulose, but may be modified in various ways.

Nomenclature. — The names for describing plants have been
derived for the most part from studies of the higher plants, they
having exclusively attracted the attention of botanists at first.
But with the light which has been thrown on the relationship

PRINCIPAL GROUPS OF PLANTS. 3

of the higher and lower groups of plants by the more recent
study of the lower forms the older terminology has been somewhat
modified. Thus, for example, we speak of the root and shoot,
with its leaves, as the vegetative organs of the higher plants,
and in describing the corresponding organs (where they exist) in
the lower plants, we either apply these terms directly, or indi-
rectly by saying that the latter are root-like, stem-like, etc. On
the other hand, we now speak of the sexual organs of the higher
plants as antheridia and oogonia (or archegonia) instead of
classifying them roughly as stamens and pistils, the latter names
being retained but with a different signification.

Plant Organs. — Depending upon the fact that the plant re-
quires nourishment for its growth and development and that it
has also to carry on the work of reproduction or propagation,
— i.e., the production of new plants, — we distinguish between
vegetative or nutritive organs and propagative or reproductive
organs. The vegetative organs, such as the root, stem and leaves
in higher plants, manufacture the food necessary for the life of
the plant, while certain other more or less specialized organs or
cells carry on the work of reproduction.

In the lower plants, however, the whole structure is much
simpler, and in some instances a cell which performs the work
of a nutritive cell at one stage may become a reproductive cell
at another, or, as in the case of the unicellular Algae, all the
various functions of the plant may be carried on by a single cell.

Generally speaking, there are two principal ways in which
plants are multiplied or reproduced : ( i ) By CELL DIVISION or cell
fission, and (2) by the formation of special cells known as
SPORES. In cell division (Fig. 85) the nucleus and cytoplasm of
a cell divide to form two new cells or protoplasts, which become
distinct by the formation of a wall or cell-plate between the two
halves. All growth in plants is dependent upon this method,
and in growing parts the cells are said to be in a state of division.
Owing to the plasticity of the plant organism, detached portions
will often grow and give rise to new plants, as in the case of cut-
tings. Growth here as in the parent plant is accompanied by cell
division. In some of the lower Algae (Fig. 10) cell division is the
only method of propagation, and as only the ordinary vegetative or

4 A TEXT-BOOK OF BOTANY.

nutritive cells of the plant are involved in the process it is some-
times spoken of as vegetative multiplication.

In both lower and higher plants, with the exceptions just
noted, reproduction is also carried on by means of spores.

FIG. 5. Ulothrix zonata. A, young filament with rhizoid cell (r); B, piece of filament
showing escape of swarm spores; C, a swarm spore or zoospore with 4 cilia; D, biciliate
gametes escaping from a filament; E, F, G, showing different stages of union of two gametes;
H, young zygote or zygospore in which the cilia have been absorbed; J, i-celled plant
developed from zygote; K, young plant organizing zoospores. — After Dodel-Port.

Depending upon their origin two classes of spores are distin-
guished, namely, (a) asexual spores, and (b) sexual spores. In
,the production of asexual spores the contents of a certain cell
called a mother cell or SPORANGIUM break up into a number of
new cells sometimes called daughter cells, which escape through
the cell-wall. In the lower plants, particularly those growing

PRINCIPAL GROUPS OF PLANTS. 5

in water or in moist places, these cells are provided with short
thread-like appendages known as cilia, which enable them to
move about in the water. They are known as ZOOSPORES or swarm
spores (Fig. 5, B, C), and each individual zoospore is able to
produce a new plant.

The number of zoospores formed in a sporangium is usually
2 to 8, as in Ulothrix, but the number may be larger. The method
of cell formation which gives rise to zoospores is sometimes
spoken of as INTERNAL DIVISION from the fact that they arise
within the old cell and retain no relation to the old wall as is the
case in cell fission. The zoospores are at first naked protoplasts,
but later, on coming to rest, may form a wall. Sexual spores, on
the other hand, are formed by the union of two cells known as
GAMETES. When the gametes are similar the resulting spore is
known as a ZYGOSPORE or zygote (Fig. 5, E, F, G). When the
gametes are unlike, the spore produced by their union is known
as an OOSPORE. In the latter case one of the gametes is larger
than the other, is less active, and is spoken of as the female
gamete, oosphere, or egg (Figs. 12, 21). The other more active
cell is known as the male gamete, antherozoid or sperm (Fig.
51, ///). The cell giving rise to the oosphere is known as the
oogonium (Figs. 12, 21), while the one in which the anthero-
zoid or sperm originates is called the antheridium (Figs. 12, '21,

22, 51).

PLANT GROUPS.

Until a comparatively recent time, botanists divided the plant
kingdom into two large groups, as follows :

The flowering plants, or Phanerogams, meaning " reproductive
process evident," so applied because the reproduction of the plant
was readily seen to develop in the flower through the agency of
the pistil and stamens.

The non-flowering plants, or Cryptogams, meaning " repro-
ductive process concealed," so applied to the lower plants like
the ferns, mosses, sea-weeds, etc., because in these plants the
method of reproduction was not known.

Now, however, after a considerable amount of study, it has
been learned that a great many of the lower plants have repro-

6 A TEXT-BOOK OF BOTANY.

ductive organs which are analogous, even if they are not exactly
similar, to those of the flowering plants. Consequently the former
classification is no longer applicable, and the following arrange-
ment is now generally adopted :

Thallophytes .......

I Fungi

Archegoniates ...... ( Bryophytes

( Pteridophytes.

Spermophytes ...... j Gymnosperms

( Angiosperms

In our study of these groups we shall see that in passing
from the Thallophytes through the various groups to the Angio-
sperms we pass from very simple forms to those which are quite
complex.

THALLOPHYTES.

General Characteristics. — This group comprises those plants
which are simplest in form and structure. They are supposed
also to represent more or less primitive types. In these the plant
body does not show a differentiation into root, stem, and leaf,
as in the higher plants, and is termed a thallus, the word thallus
meaning a " mass " of cells. The cells making up a thallus are
all alike and are not differentiated for special functions. How-
ever, it must not be thought that every Thallophyte is charac-
terized in this way. Many of the Thallophytes have cells or
groups of cells which become specialized, i.e., set apart for a
particular function, as for example the reproductive cells. We
see, therefore, that the word Thallophyte is a general term and
is applied to many plants which are not thallus-bearing, but
which are really closely related to the simpler forms to which
the word Thallophyte is strictly applicable. When made up of
a mass of cells they may branch in various ways, but the essential
structure remains more or less uniform throughout.

The Thallophytes vary in size and general appearance from
minute, unicellular organisms to those which are filamentous
and delicately branched, and even becoming leaf-like structures,
attaining a length in some of the marine algae of a thousand feet

PRINCIPAL GROUPS OF PLANTS. 7

and even more. Some of these are more or less complicated in
structure.

The Thallophytes are subdivided into two important groups,
as follows:

The Algae, plants producing chlorophyll or green cell-contents,
and hence capable of manufacturing food from the inorganic
substances air and water.

The Fungi, plants not producing chlorophyll, and hence not
capable of forming their own food, but living upon dead or
living matter.

Before considering the Algae proper we will consider two
groups which are very simple in structure and whose method of
reproduction as well as life history is also very simple; namely,
the Blue-green Algae and the Bacteria. The Blue-green Algae are
ordinarily classified with the Algae, and the Bacteria are very
often grouped with the Fungi. Owing to certain resemblances
between these two groups it is convenient to arrange them to-
gether under the name Schizophytes, or fission plants.

SCHIZOPHYTES.

Characteristics. — The name Schizophyta means " fission
plants," and is applied to this group because the reproduction is
chiefly by means of the division of the cells, which may occur
either at the middle of the cell and in one direction, in which
case a series of connected cells are formed, or in two or three
directions, giving rise to spherical aggregates or colonies. They
do not usually contain chromatophores, and the coloring sub-
stance, when present, is either uniformly distributed throughout
the cell or occurs on the external surface of the protoplasmic
content.

There are two chief groups: the one corresponds to Algae,
and, while they do not contain a simple green substance, they are
for the most part of a blue-green color, although they may assume
various shades of orange, yellow, and brown, even appearing
chocolate or purplish-red at times. The second group, correspond-
ing to the Fungi, comprises the Bacteria or Schizomycetes, which
are distinguished for the most part by being nearly colorless and
only occasionally of a reddish or green color.

8 A TEXT-BOOK OF BOTANY.

SCHIZOPHYCE^;, OR FISSION ALG^E.— This group of
plants, also known as Cyanophyceee or Blue-green Algae (Fig. 6),
are generally found in more or less stagnant water and are charac-
terized by having associated with the chlorophyll a definite blue-
green principle known as phycocyanin. However, many of these
Algae contain other pigments in such quantity as to give them dis-
tinct colors much like those found in the red and brown Algae, such
as Trichodesmium, a filamentous Alga giving the Red Sea its char-
acteristic appearance. Some of these live at the highest tempera-
ture known to support life ; some developing, as Gloeocapsa, on the
sides of the geysers in the Yellowstone Park. These forms have
very wide habits, some living, as Stigonema, in symbiosis with
fungi ; some, as Nostoc, are endophytic in habit, living in the de-
pressions of various plants, and others, as Mastigocoleus, boring
into shells.

They are found mostly in fresh water, and some, as Uroglena,
cause considerable trouble in public water supplies by reason of
their breaking down the cell-wall and the liberation of a fetid
oily substance.

While these plants do not produce true spores, yet they are
able to tide themselves over adverse conditions by producing rest-
ing bodies through the formation of a thicker membrane and a
more concentrated cell-content. In this condition they are able to
hold over for several years and then grow when the conditions of
temperature, nutrition, etc., are suitable for their germination. As
a rule, they grow best in shallow, stagnant water with the rela-
tively high temperature of the summer months. When public
water supplies are polluted by these blue-green Algae it has been
found that the Algae are completely destroyed by the addition of
a very small amount of copper sulphate to the reservoir. As
small a quantity as one part per million is sufficient to accomplish
this result, not only killing the troublesome organisms, but pre-
venting their development for some months to come. A few of
the common forms will be considered.

Gloeocapsa is one of the simplest of the Blue-green Algae
(Fig. 6), consisting of spheroidal cells from 0.0035 to 0.005 mrn.
in diameter, of a yellowish or brownish-yellow color, and usually
embedded in groups of two or some multiple of four in an olive-

PRINCIPAL GROUPS OF PLANTS.

A mass of cells after numer-
ous divisions, all surrounded
by a mucilaginous envelope.

GLOEOCAPSA.

Single cell just after
division. The two
daughter cells re-
tained in a gelatinous
mass. Diameter
about 4 microns.

A single colony.
Diameter of colonies varying Single cell showing

from 40 to 290 microns. spiral chromatophore.

Length, 14 to 18 mi-

UROGLENA ««*

Heterocyst which divides the
filament into smaller filament*.

Thick-walled resting cellt.

Filamentous colonies coiled
within the masses of jelly

Spherical gelatinous masses
as found floating in /ponds.
About twice natural size.

Part of a single filament
Diameter, 4 to 12 microns.

u

OSCILLATORIA

Diameter of filaments,

5 to 50 microns.

Decaying cell
unctioning as a heterocyst.

Filaments, about 10 to 60
in diameter.

LYNGBYA

FIG. 6. Forms of Cyanophyceae or Blue-Green Algae. — Adapted from Engler and
Prantl and Somewhat modified by Lobeck.

io A TEXT-BOOK OF BOTANY.

brown gelatinous stratum, this arrangement due to the cell divid-
ing in all directions. They occur on moist earth, stones, wharf
pilings, and even on window panes of greenhouses, thus being
distributed in both fresh- and salt-water regions. They some-
times form a kind of crustaceous stratum, and sometimes soft,
slimy masses sufficiently abundant that they can be stripped by the
handful from dripping, partially shaded rocks. Owing to the
variation in color and general habit of the plant a great many
species have been described, but up to the present time about 60
have been sharply distinguished.

Oscillatoria, formerly known as Oscillaria, is the name applied
to a simple filamentous blue-green alga (Fig. 6) that is char-
acterized by movement from side to side as in a pendulum, due,
as has been suggested, to the movement of spiral masses of proto-
plasm extending from cell to cell. These filaments consist of a
series of disk-shaped cells like a pile of coins placed side by side,
the end cell being rounded off and more or less convex. The con-
tents are made up of a finely granular substance differentiated
into two areas, a dark central nuclear portion, and a peripheral
holding the pigment, which may vary from a bluish-green to dark
olive-green or even red sufficiently intense to give the water a
red color. The filaments vary from o.ooi to 0.005 mm. in diame-
ter, though they may attain a size of 0.050 mm.

Oscillatoria is usually found on wet, marshy grounds, in
ditches among decayed vegetable matter, on wood subject to hot
waste from steam engines, around pumps and cisterns, and in
greenhouses. It occurs in fresh and salt water.

Lyngbya somewhat resembles Oscillatoria, but does not show
any oscillations and the filaments are each provided with a dis-
tinct sheath (Fig. 6). It forms late in the summer in large tufts.
It is of a bluish-green color, forms long filaments, occurring in
the late summer upon Zostera and other Algae. The groups are
large and characteristic and have been given the common name
Mermaid's Hair. The cells are about 0.030 mm. in diameter.

Uroglena is a form which is more or less oval or pear-shaped,
about 0.014 to 0.018 mm. in length, and extended into a stalk below,
the upper end being provided with two unequal cilia (Fig. 6).
The wall secretes a large amount of mucilage. The organisms

PRINCIPAL GROUPS OF PLANTS. n

arrange themselves in a radiating sphere, with the cilia at the
periphery. Each cell of the colony contains a more or less spiral,
yellowish chromatophore, bearing a reddish spot at one end, a
nucleus at the centre, and a few vacuoles. The cells secrete a
large quantity of oil, which is of an unpleasant, fish-like odor, and
is due either to the decay or breaking up of the cells by mechanical
means. This breaking up of the cells is the cause of the disagree-
able odor occasionally found in public water supplies. Uroglena
is found in New England and has been reported as far west as
Indiana, and is probably rather widely distributed in the United
States. It seems to thrive best in cold temperatures, usually
occurring in greatest numbers when the water is frozen over.
It multiplies by cell division, which takes place when the colony
becomes rather large. It also produces resting spores which
enable the organism to survive conditions which would otherwise
exterminate it.

A closely related organism, Synura, is responsible for the ripe
cucumber odor which was formerly thought to be caused by
fresh- water sponges'.

Nostoc, a form occurring in filaments like a string of pearls, is
made up of spherical or elliptical cells, the whole being surrounded
by a thick, mucilaginous membrane (Fig. 6). Usually one finds a
number of these filaments growing together in a mass which can
be seen by the naked eye floating in the water. These masses
vary from globular to sub-globular, are irregularly divided or
occur in definitely expanded groups. These forms are marked by
having two kinds of cells, the one filled with a granular proto-
plasmic content, the other being free from protoplasm and some-
what larger than the other cells. These latter are fewer in number
and are called " heterocysts," which means simply " other cells."
At these latter cells the filaments separate, and thus many new
colonies are formed. Nostoc is mostly of an olive-green color,
but may be dark bluish-green, dark brown, or light yellow or even
colorless. It occurs mostly in fresh-water ponds, seldom in
brackish water, being found on damp rocks, on mosses and more
or less submerged plants, and variously in limestone springs or wet
calcareous rocks or on aluminous soil. The colonies vary greatly
in size and color, and while some of them may be of microscopic

12 A TEXT-BOOK OF BOTANY.

size at one period, later they may be as large as peas or cherries.
Owing to their variation in appearance in different seasons various
names have been given to the same form by different investigators.
They are also associated with lichens. According to systematists,
the forms of Nostoc are arranged according to their aquatic or
terrestrial habits.

SCHIZOMYCETES, OR BACTERIA.— The Bacteria, or
Fission Fungi, occupy rather an anomalous position, some writers
classifying them with Fungi and some with Algae. They are i-
celled plants, microscopic in size, and of various shape. The con-
tents consist of protoplasm and a central body in some cases, which
is looked upon as a rudimentary nucleus. They are more or less
colorless, but sometimes produce a distinct pigment called bacterio-
purpurin which is rose-red or violet, and occasionally a chlorophyll-
green color substance. They are capable of multiplying by division
in one, two, or three directions, and under favorable conditions in-
crease very rapidly in number. The wall is more or less albumin-
ous in character, in this "respect resembling the wall of the animal
cell, and is provided with one or more cilia, or flagella, the number
and position of which have been used as a basis of classification.
Sometimes the walls of the Cells become mucilaginous, so that the
,bacteria hold together, forming a mass known as a zoogloea.
Bacteria may form resting spores which arise in two ways. In
one case the contents round off and take on a membrane forming
a so-called ENDOSPORE ; in the other case the plant body is trans-
formed directly into a spore known as an ARTHROSPORE, as in
some of the Blue-green Algae. This body is not strictly a spore,
but is in the nature of a resting cell (Fig. 7). Two classes of
bacteria are frequently distinguished, as follows : Aerobic, or
those which require oxygen for their development and conse-
quently grow best when they have access to air or oxygen; and
anaerobic, or those whose development is accelerated under re-
verse conditions, as in underlying tissues or in the interior of
cultures.

Occurrence. — Bacteria occur everywhere in nature, and play
a most important part in decay and putrefaction, in that they
change dead animal and plant tissues back again into simple inor-
ganic substances, as carbon dioxide, hydrogen, water, ammonia,

PRINCIPAL GROUPS OF PLANTS. 13

etc. They serve a useful purpose in many technical operations, as
in the making of cheese, acetic acid, fermentation of tobacco,
curing of vanilla and many vegetable drugs, and in soil nitrification,
helping to change ammonia into nitrates — one of the sources of
the nitrogen used by plants. Many of them are disease-producing,
or pathogenic, and are the cause of a number of infectious dis-
eases in man and the lower animals, and plants as well. They are

FIG. 7. Bacillus subtilis (hay bacillus), a, Small rod-like organisms such as are
found in an infusion of hay, or bouillon; b, zoogloea or mass of bacilli forming the "skin"
on the surface of infusions; c, chains of organisms forming spores; d, individual bacilli
showing flagella, which are only seen after staining. — After Migula.

injurious in two ways : in one case they consume the tissues of the
host, as in tuberculosis, and in the other they produce powerful
poisonous substances, or toxins, as in diphtheria.

Glasses of Bacteria. — In order to study Bacteria they are
grown upon nutrient media, such as sterile bouillon, potato, milk,
etc. They are divided into a number of classes, depending for
the most part on the shape of the cell: (i) The Sphserobacteria,
or Cocci, are those whose cells are spherical or spheroid, and in

I4 A TEXT-BOOK OF BOTANY.

which division takes place in one, two, or three directions of space.
Very few of this group are provided with cilia. According to the
number of cells in a colony they are distinguished as Micrococci,
Diplococci, etc. (2) Bacteria proper are elongated, rod-shaped
organisms in which division occurs in only one direction, namely,
transversely to the long axis, and only after a preliminary elon-
gation of the bacterium. The Bacteria are subdivided into two
important groups, namely, Bacterium and Bacillus. The Bacilli
are motile organisms and produce endospores (Fig. 7), whereas
the Bacteria are non-motile and do not usually produce endospores.
(3) Spiral bacteria constitute the third principal group and are
characterized by the cells being spirally coiled. Division is in
only one direction. These bacteria are usually motile, and seldom
produce endospores. (4) There is another important group
which includes the Sulphur Bacteria, of which the most common
one is Beggiatoa. These occur in long threads, and move in an
undulating manner much like Oscillaria, one of the Blue-green
Algae. They are found in sulphur waters, as in sulphur springs,
and contain sulphur granules.

Bacteriological Technique. — Principally because of the
minuteness in size of micro-organisms a different technique is
required in their study from that required in the study of the
higher plants. In the first place it is difficult to isolate them
so as to be able to study individual forms. Another difficulty is
to prevent contamination after they are isolated. And even
though a pure culture is obtained it is difficult on purely morpho-
logical grounds to differentiate the various forms, as they are all
so much alike.

I. While it is comparatively easy to prepare a sterile solution, —
that is, one in which all life is absent, — it is very difficult to prevent
subsequent contamination under ordinary conditions. Even when
a cork- or glass-stoppered bottle for keeping liquids is used it is
difficult to prevent the entrance into and development of micro-
organisms in the liquids. The use of stoppers consisting of plugs
of absorbent cotton was first suggested by Schroeder and von
Dusch in 1854. They found that if flasks containing liquids,
which under ordinary conditions were likely to decompose, as
beef broth, etc., were stoppered with plugs of absorbent cotton

PRINCIPAL GROUPS OF PLANTS. 15

and the liquid then boiled for some time it would keep
indefinitely.'

II. It remained for Koch and Pasteur to show what took
place in the boiling of the liquid, who at the same time developed
the principles of sterilization in bacteriological work. These
authors discovered that micro-organisms have two stages of de-
velopment, one of which is active and the other resting, the latter
being known as the egg or spore condition. They found that the
organisms in the active condition were completely destroyed on
heating the solution containing them for 30 minutes at 100° C.
If this solution was allowed to stand for 24 hours or longer
there would be evidences of decomposition, which was due to the
fact that the spores representing the resting stage of the organ-
isms were unaffected by the first heating and developed into
the active stage. As a result of further experiments they found
that if the solution were heated on the second day for 30
minutes at a temperature of 100° C. the second growth of organ-
isms was destroyed, but it was found that the solution might still
undergo decomposition in the course of time, owing to the later
development of a few remaining spores. It was, however, found
that heating the liquid again on the third day was sufficient to
kill all of the spores as well as the organisms in the active stage.
By repeating these experiments the authors confirmed theii
observations and established the process known as discontinuous
sterilization, which simply means that if a solution of a putrescent
or fermentative substance is heated on three consecutive days for
30 minutes at a temperature of 100° C., the flask or bottle being
stoppered with absorbent cotton, it will keep indefinitely. Instead
of using a plug of absorbent cotton the neck of the flask can be
drawn out into a narrow tube and directed downwards (see Re-
agents). The time required for producing a sterile solution, — that
is, one free from micro-organisms or their spores, — can, however,
be much reduced by increasing the temperature, or pressure, or
both. By use of the autoclave, in which the pressure can be
increased from 10 to 20 pounds, sterilization can be accomplished
in 30 minutes by using a temperature of 110° C.

III. As already indicated, one of the greatest difficulties is to
isolate the organisms. In a cubic centimetre of water there

16 A TEXT-BOOK OF BOTANY.

may be a million organisms representing various groups of bac-
teria. In trying to solve the problem of their separation it
occurred to Koch that if he could secure a medium which was
solid at the ordinary temperature and liquid at a slightly higher
temperature, he could mix a certain quantity of liquid containing
micro-organisms with the medium in a sterile condition, and then
by solidifying the mixture the organisms would be fixed, and
thus from each organism a colony would be developed which
could be isolated and further studied. We are indebted to Koch
for the use of solid culture media like nutrient gelatin and
nutrient agar in the study of these organisms.

IV. The application of stains for differentiating the various
organisms was introduced by Weigert in 1877. Staining is of use
in the determination of the number of flagella of certain organisms,
in the study of spores, and the identification of certain pathogenic
organisms, which occur in mucus and pus, as tubercle bacilli,
etc. Gram's method of staining is of great use in differentiating
many pathogenic as well as non-pathogenic organisms, and is of
importance in classifying bacteria.

ALG.E.

Characteristics. — Algae are characterized by their habit of
living in water or in moist places. They vary from simple, i -celled
microscopic forms to those of great size like the sea-weeds. In
the various types, however, the cells show little variation in shape.
All the Algae contain more or less of a green coloring matter, even
though it may be concealed by other pigments of a blue (as in
Schizophyta), brown, or reddish color. The possession of this
green cell-content or chlorophyll enables the Algae, in the presence
of sunlight, to manufacture food substances from simple materials
like carbon dioxide and water.

The occurrence of chlorophyll can be readily demonstrated by
extracting it with 95 per cent, alcohol. Even in the most delicate
of the red Algae it can be shown by placing the fresh material in
a strong solution of common salt and afterwards extracting the
chlorophyll with alcohol, the other pigments being unaffected.

Algae are sometimes grouped as Fresh- Water Algae, includ-

PRINCIPAL GROUPS OF PLANTS. 17

ing most of the Green Algae, and the Marine Algae or Sea-weeds,
including most of the brown and red forms.

Algae are classified in three natural groups, not only on account
of color differences, but because of certain corresponding struct-
ural relationships, thus :

Chlorophyceae (Green Algae).
Phaeophyceae (Brown Algae).
Rhodophyceae (Red Algae).

Arranging the Algae in this way provides the simplest classi-
fication. But in addition to these groups there is another some
what isolated group that will be taken up first before the Chloro-
phyceae, — namely, the Conjugatae. These are Green Algae con-
sisting of either single cells or a chain of cells united into threads
and further characterized by dividing always in the one direction
so that a filament results. They furthermore do not produce
zoospores, but produce zygospores as a result of a union of two
similar or only slightly different cells. After a period of rest
they break from the outer membrane and develop directly into new
vegetable cells. To this class the Desmids and Spirogyra belong.

The Desmids are unicellular Algae, varying from torpedo-
shaped to variously branched forms, occurring even in chains.
The protoplast is usually separated at or near the middle, where
the nucleus is located, dividing the cell into two symmetrical por-
tions (Fig. 8, E). In the protoplast is a more or less complex
chromatophore, through the center of which are distributed a
number of globular pyrenoids. The latter are distinct structures
embedded in the chromatophores of Green Algae and consist of
a central protein substance surrounded by a number of starch
grains, and, therefore, give a purple reaction with iodine. Owing
to the fact that the Desmids are motile they were formerly con-
sidered to be members of the animal kingdom. The movement is
slow and steady and largely influenced by the light. There is also a
circulatory movement frequently observed in the contents of
active living material. In addition, there is almost always observ-
able at the ends a well-defined spherical vacuole containing
numerous small crystals of calcium sulphate which exhibit a
dancing movement due to surface tension and is known as molec-

iS

A TEXT-BOOK OF BOTANY.

ular or Brownian movement. Reproduction is either by simple
division or by the union of two Desmids. In the latter case the
contents of each flow together into a connecting tube formed by
the union of the two Desmids, the resultant mass rounding off to
form a zygospore.

FIG. 8. Forms of Desmids in longitudinal view and transverse section. A, Meso-
tcenium Braunii; B, Ancylonema Nordenskioldii; C, Penium digitus; D, Cylindrocystis crassa;
E, Closterium moniliferum; F, Spirotcenia muscicola; G, Pleurotcenium trabecula; H, a Docid-
ium baculum; Ha', D. dilatatum. — From Wille in Engler and Piantl's "Die Naturlichen
Pflanzenfamilien."

Spirogyra. — Another one of the common Green Algae is
Spirogyra (Fig. 9), one of the pond-scums, which in the spring
forms floating green masses on ponds and shallow water. The
plant-body consists of a chain of cylindrical cells forming long
threads or filaments. The transverse walls are sometimes pecu-
liarly thickened. The chromatophores occur in one or more spiral

PRINCIPAL GROUPS OF PLANTS. 19

bands (Fig. 9, //), which extend from one end of the cell to the
other. In these bands are embedded protein bodies known as
pyrenoids. The nucleus lies in the centre of the cell and is con-
nected with the cytoplasmic layer lining the walls of the cell by
delicate threads of cytoplasm.

Spirogyra may be propagated vegetatively by one or more
cells of a filament breaking off and forming new individuals by

FIG. 9. II. Spirogyra stictica, showing parts of two filaments with band-like chroma-
tophores (chloroplasts), in which are embedded spherical pyrenoids. Nuclei are shown
in some of the cells with delicate threads of cytoplasm radiating from them. Two of the
cells (a, a) of the adjoining filaments (A, B) are beginning conjugation. I, 5. Heeriana,
showing different stages of conjugation. In the upper cells, the contents have rounded off
previous to the rupture of the adjoining walls of the two filaments. The two middle cells
show the contents passing from one cell into the opposite cell. In the lower cell to the
right the zygospore is shown. — After De Bary.

cell division. The plant is also reproduced by means of zygo-
spores, as follows: The cells of two adjoining filaments each
send out processes (Fig. 9, //, a, a), which meet; the end walls
are absorbed, forming a tube through which the contents from one
cell pass over into the other (Fig. 9, /) ; the contents of the two
cells then fuse, after which the mass becomes surrounded by a
cellulose wall. The spore thus formed may remain dormant over
winter, and the following spring germinate and form a new Spyro-

20 A TEXT-BOOK OF BOTANY.

gyra filament or plant. This method of reproduction is known
as CONJUGATION, and the zygospore is called a resting spore. It
should be explained that certain cells, as well as spores, may lie
dormant for a period, as during the winter season or at other
times, when the conditions are unfavorable to growth, and then
renew their activities, these being known as " resting cells."

CHLOROPHYCE^. — The Chlorophyceae, or Green Algae, are dis-
tinguished by usually having a green color, due to chlorophyll, and
by having no other pigment. The cells contain one or more nuclei.
They are either unicellular or made up of many cells forming fila-
ments or flat sheets. They occur either singly as simple cells or
in groups representing a single individual or a colony. They are
found mostly in fresh or salt water, usually being microscopic
in size so as not to be noticed, but often attracting attention when
they occur in sufficient quantity to form a scum on the surface.
The reproduction is mostly by ciliated cells called zoospores or
swarm spores. Reproduction also takes place by the union of
the zoospores and through the fertilization of egg cells. The
sexual spore resulting from this union of like cells (forming
a zygospore) or of unlike cells (forming an oospore) seldom
develops immediately, but usually undergoes a resting period be-
fore growth is continued

Protococcus. — One of the commonest of the Green Algae
as well as one of the simplest is Protococcus (Pleurococcus) vul-
garis (Fig. 10). It occurs as a green coating, in both winter and
summer, on the moist bark of trees, moist ground, and stone
walls, and is a component of some lichens. The plant is i-
celled, more or less spherical, and at one stage contains a number
of chlorophyll grains which finally unite to form a single plate
which lies against the wall and is known as a CHROMATOPHORE.
Besides it contains a considerable amount of oil. An allied
species (Protococcus viridis) contains the sugar erythrite. The
plant usually reproduces by simple division, — that is, one cell
or plant divides to form two. The divisions may continue by the
production of another cross wall, so that four cells result. Under
favorable conditions, division may take place by the formation
of still another wall at right angles to the other two. In this
way two, four and finally eight individuals arise which adhere

PRINCIPAL GROUPS OF PLANTS. 21

more or less to one another, thus forming colonies. The number
of individuals in a colony depends upon the number of indi-
viduals in the colony when division begins and the extent to
which division is carried. Thus if there were four cells in a
colony to begin with and division took place in three planes, there
would be thirty- two cells in the colony at the end of the period.
The development of the green coating on the barks of trees,
due to the growth of Protococcus and the protonema of mosses,
is usually thought to be more pronounced on the north side. This,
however, is a slightly false notion. The fact which determines
the position of these plants is the quantity of moisture available.
The south and southwest sides of trees in the northern hemisphere
are exposed to more light and heat and consequently are apt to be
drier, with the result that they are rarely covered with coatings of

FIG. 10. Protococcus vulgaris. Different stages of division of the cell. — After Wille.

Protococcus and mosses. The under side of slanting trees is a
very favorable place, as are also the lower slanting surfaces near
the ground of large upright trees, because in these places the
water is more likely to be conserved. A careful investigation by
Kraemer showed a more abundant growth of green plants on the
east and southeast exposure, although the north side of many trees
showed good growth also.

Volvox occurs widely distributed throughout the United
States in ponds and pools of fresh water. It is most abundant
in warm weather, but also found in midwinter. It appears as a
minute spherical colony about y2 mm. in diameter, made up of
numerous cells, the number ranging from several hundred to
many thousand (Fig. 11). The cells at the periphery are pro-
vided with cilia, so that the colony rolls slowly through the
water. Each cell contains a chloroplastid in which starch granules
and often a red pigment spot are present. The asexual reproduc-

22 A TEXT-BOOK OF BOTANY.

tion is through the formation of daughter colonies within the
mother colony, and these after a time develop motile cells like the
parent, which swim about and finally escape. A sexual method
of reproduction also occurs in which there is a union of cells
within the spheres, the resulting cells after germination forming
swarm spores that cling together to form a new colony.

Hydrodictyon, or Water Net, is a form often very abundant
in sluggish and stagnant waters. It consists of a number of cells
forming a net, the meshes of which are usually hexagonal or
pentagonal in shape, depending on the number of cells outlining
them (Fig. n). The cells are all alike, cylindrical in form,
attaining sometimes a length of i cm., and usually contain a
number of nuclei. The green chromatophore occurs in. a plate
at the periphery of the cell and usually contains numerous
pyrenoids.

The asexual reproduction is by means of zoospores which
are formed simultaneously in large numbers, sometimes number-
ing many thousands in each cell. These ' zoospores as formed
inside of the mother cell show more or less definite movement
and arrange themselves finally to form a new net. The sexual
reproduction is characterized by several stages, (i) Some of the
zoospores are liberated through a pore in the cell- wall of the
mother cell and after swimming around for some time pairs of
them unite, forming zygospores. (2) After a resting period each
zygospore develops 2 to 5 zoospores, which escape into the water
and develop into irregular, sharp-angled cells, called polyhedra,
which persist through the winter. (3) When these polyhedra
develop, small zoospores are again formed, and these arrange
themselves to form a net inside of the polyhedron, which then
escapes and increases in size.

Vaucheria (Fig. 12) is another common green alga which
may also be selected as showing the habits of this group of
plants. The plant has a branching thallus and lives in shallow
water or on moist earth, being attached to the substratum by
means of delicate root-like processes sometimes spoken of as
rhizoids (Fig. 12, w). In the thin layer of protoplasm lying near
the wall are numerous nuclei and small oval chromatophores.

PRINCIPAL GROUPS OF PLANTS.

Single
polyhedron.

Net developing
inside of polyliedro

OEDOGONIUM.

Three stages in sexual reproduction.

HYDRODICTYOX

ULVA

Mature Colony— Diameter 2 mm.

A. Egg cell, before fertilization.

B. Oospore.

C. Daughter colony

VOL VOX

FIG. II. Forms of Chlorophyceas or Green Algae. — All adapted from Engler and
Prantl except Ulva. Drawn by A. K. Lobeck.

24 A TEXT-BOOK OF BOTANY.

Numerous oil globules are also found in the protoplasm, and cal-
cium oxalate crystals may occur in the 'cell-sap.

Vaucheria furnishes an example of a plant whose interior is
not segmented by cell-walls. In other words, the cavity within
the outer or enclosing membrane is continuous, and such a plant
is said to be coenocytic, — i.e., like a syphon. But it should be borne
in mind that the plant contains a great many nuclei, and, as we
have seen (page 2), a nucleus with its associated cytoplasm

FlG. 12. Vaucheria sessilis. A, sporangium from which the multiciliate zoospore is
escaping; B, resting zoospore; C, D, germinating zoospores with growing point (s); E,
plant showing root-like organ of attachment (w), spore from which the plant is developing
(sp); F, showing in addition two oogonia (og) and an antheridium (h). — After Sachs.

constitutes a unit of work. Hence such a plant as Vaucheria is in
a certain sense equivalent to a plant having as many uninucleate
cells as it has nuclei. It would probably be better to call such a
plant multinucleate rather than unicellular.

Reproduction by means of asexual spores is brought about as
follows (Fig. 12, A) : A cross wall is formed near the end of one
of the branches, the end portion constituting a sporangium. The
contents, including numerous nuclei, group themselves into one
large zoospore, which escapes through an opening in the sporan-

PRINCIPAL GROUPS OF PLANTS. 25

gial wall, and after swimming about for a time comes to rest
and germinates, giving rise to a new plant (Fig. 12, C, D). This
large zoospore is multinucleate and multiciliate, there being two
cilia for each nucleus, and by some botanists is considered to be
an aggregation of numerous biciliate zoospores. It is also of
interest to note that the zoospores of Vaucheria appear to arise by
a grouping of the cytoplasm and the nuclei already existing in the
sporangium rather than by repeated divisions of a single nucleus.

Another method of reproduction in Vaucheria (Fig. 12, F)
is that by means of oospores, or spores formed by the union of
egg and sperm cells. Two special branches are formed on the
thallus as short side shoots. One of these branches, known as
the oogonium (Fig. 12, og), is somewhat egg-shaped and sepa-
rated from the thallus by means of a cross wall. It contains a
great many chromatophores and considerable oil, and has a com-
paratively thick wall. The apex is somewhat beaked and con-
tains colorless protoplasm. The second branch, which is known
as an antheridium (Fig. 12, h), is smaller, somewhat cylindrical
and curved towards the oogonium. It is also cut off from the
thallus by means of a cross wall. The antheridium contains very
little chlorophyll, but a great many sperm cells. These are oval
or egg-shaped and have two cilia, one at each end. The sperms
escape from the apex of the antheridium and enter an opening
at the apex of the oogonium, one of them uniting with the egg
cell, which then develops a thick membrane, the resulting oospore
being a resting spore.

Ulva, or Sea Lettuce, is a common form found all over the
world, especially in brackish waters. In its usual form it consists
of flat, thin, unbranched fronds which are more or less ovate or
orbicular in outline and frequently deeply incised, sometimes be-
coming linear or even ribbon-shaped (Fig. n). The fronds con-
sist of two layers of cells, which are either in close contact with
each other or else at maturity separate so as to form a tubular
frond. It sometimes occurs in large quantities in the shallow
water along our coast, and is conspicuously disagreeable by its
resemblance in shape to the swollen intestines of some animal.

CEdogonium is a filamentous alga occurring usually in simple
(unbranched filaments and attached by a disk-like cell or hold-

26 A TEXT-BOOK OF BOTANY.

fast (Fig. II,). It occurs in meadow pools or ponds, frequently
in streams attached to rocks near rapids. The cells are somewhat
elongated and contain a large, irregular chromatophore with
pyrenoids. Most of the cells are vegetative cells, interspersed
among which are the cells producing the spores. Zoospores are
produced singly in the cells and are provided with cilia at one
end. After swimming about for some time they attach themselves
at this ciliated end to a substratum and develop into filaments.
Two other types of cells are formed and which give rise either
to oogonia, the female organ containing a large egg cell, or to
antheridia, the male organ containing many sperms. The union
of a sperm with an egg cell produces an oospore with a very thick
wall, capable of over-wintering and developing again when con-
ditions are favorable.

THE CHARACE/E, or Stoneworts, is a highly differentiated
group that is considered as a distinct class between the Chloro-
phycese and the Phseophycese. They stand so entirely by them-
selves that many authorities do not consider them as even Algae.
They consist of jointed stems, from the nodes of which whorls of
from 4 to 10 leaves are developed, and these bear the sexual
organs (Fig. 13). In many of the members of this family the cell-
wall is incrusted with lime salts. Chara occurs in great masses
in the bottom of ponds and shallow lakes. It occurs in sufficient
quantity in many places so that the body of water has a distinct
orange color, due to the immense numbers of antheridia. The
plant is of such luxuriant growth that if single individuals are
kept in an aquarium or large glass vessel it will greatly multiply
during the winter and persist for many years. In ponds where
Chara occurs large quantities of lime are deposited, so that in
ancient deposits now exposed to view one often finds imbedded
therein the remains of the spore-fruits.

In the long cells or internodes there is a large vacuole and
a thin layer of protoplasm containing a central nucleus and a
large number of oval or lens-shaped chromatophores. In some
forms, especially in Nitella, the inner protoplasmic layer shows
a streaming movement. This is very interesting, as a distinct
streaming movement does not occur in most plants and is limited
to a few water plants, the staminal hairs of Tradescantia, the leaf

PRINCIPAL GROUPS OF PLANTS.

27

hairs of Cucurbita and Urtica and the hyphse or Rhizopus, etc.
This streaming movement in plants like Characeae, as pointed out
by Pfeffer (Physiology of Plants), has in most cases a definite
purpose. It is, in any case, always possible that the streaming
movement may be an accessory but unavoidable accompaniment
of some other form of vital activity. In Chara and Nitella the

FIG. 13. Stonewort or Chara. At left showing the habit of the plant with minute
reproductive organs on the leaves. At right enlarged view of reproductive organs. A,
mature organs showing (a) antheridium, (S) oogonium surmounted at the top by a crown
of cells (c); b, stem of plant; /3', /3", whorl of leaves, some of which have been removed, as
at /3; B, a young antheridium (a), with young oogonium (SK), together with the adjoining
cells of the stem; the whorl of leaves not represented. — A, after Wille; B, after Sachs.

streaming endoplasm (inner layer of protoplasm) does not cover
more than 2 to 3 mm. per minute. The activity of the streaming
is influenced by sunlight, oxygen, acids, chloroforn^ etc. Two
kinds of protoplasmic streaming are recognized : ( i ) in which the
movement is confined to the layer enclosing the central vacuole,
that is known as " rotation," and (2) in which the streaming
follows more or less irregular paths up and down the strands of
protoplasm, crossing the latter, which is called " circulation."

28 A TEXT-BOOK OF BOTANY.

Vegetative reproduction is much like that of the higher plants,
through the production of root- tubers or bulbils, stem bulbils, and
through special branches arising at the nodes. The bulbils are
filled with starch and are capable of over- wintering. The sexual
mode of reproduction is through the activity of oogonia producing
oospores, and antheridia producing antherozoids or sperms. These
are adjacent to each other at the nodes, the oogonium forming a
central elliptical cell which is surrounded by a crown of cells
through which fertilization takes place (Fig. 13).

PH^OPHYCEvE. — The Phseophyceae, or Brown Algae, are dis-
tinguished by having brown chromatophores. They are mostly
found in the colder waters of the ocean, and are either free or
attached to a substratum. They vary in size from microscopic
organisms to delicate filamentous or cord-like forms, and may be-
come of enormous size. Some are called rock-weeds and give the
characteristic color to the rocks between low- and high-tide marks.
Others are known as " kelps," and these grow near the low-water
mark. They vary in color from an olive-green to a brown. The
chlorophyll may be extracted by alcohol, leaving the other pig-
ments, phycoxanthin and phycophaein. Many of these Algae are
rich in iodine, being one of the sources of this element. They also
contain large quantities of sodium, and were used at one time
in the manufacture of sodium, and have been used to fertilize the
soil in parts of Europe as well as in New England.

They are more complex in form than the Green Algae, and
are distinguished by having hold-fasts which, while not in the
nature of true roots, yet serve to hold the plant. They may also
develop stems and bear leaf-like structures of many varied forms.
Others also develop swollen bladders which contain oxygen and
which serve to buoy up the plant.

Fucus, or Bladder Wrack, is one of the common rock-weeds
(Fig. 14, B). It grows near the surface of the water, attached
to rocks, and produces a regularly dichotomously branching
thallus. Some of the forms in the upper branches produce air
bladders which are spherical or slightly elongated and usually in
pairs. The margins of the branches are either entire or somewhat
serrate. The tips of older branches become more or less swollen
and are termed receptacles. They are dotted over with minute

PRINCIPAL GROUPS OF PLANTS. 29

cavities, called conceptacles, and these contain the reproductive
organs. These consist of oogonia and antheridia, which may be

FIG. 14. Some common marine algae. A. Laminaria, showing portions of three leaf-
like thalli and hold-fast; B, dichotomously branching thallus of Fucus; C, Sargassum, or
"gulf weed," showing a thallus resembling a leafy branch, with swollen, berry-like air
bladders, which act as floats; D, Dasya, a delicate branching filamentous sea-weed, attached
to a blade of eel-grass; E, dichotomously branching thallus of Chondrus, or Irish moss;
F, leaf-like thallus of Grinnellia; G, densely, but delicately branched thallus of Polysiphonia.
A, B, C are Brown Algae and D, E, F, G are Red Algas.

present on the same or on different plants. The egg cells and the
sperm cells escape into the sea-water, and after their union an

30 A TEXT-BOOK OF BOTANY.

oospore results, which, upon finding a favorable resting place,
begins shortly to develop into new Fucus plants. The plant
contains both iodine and bromine, chiefly combined with salts of
sodium and potassium, and was at one time used in medicine. It
also contains a bitter principle and a considerable amount of
mucilage.

ASCOPHYLLUM, a rock-weed closely related to Fucus, is dis-
tinguished from this genus by the fact that the branches are desti-
tute of midribs and the spores occur in groups of four instead of
eight. The frond is thick and narrow, branching somewhat
dichotomously, and at intervals produces large, conspicuous floats,
which are broader than the frond. The plants occur from ^ to 2
metres in length. The fruit is found in lateral branches in winter
and spring, and in June the receptacles fall off and are sometimes
found in immense quantities, covering the bottom of tide pools.

LAMINARIA is one of the common kelps or devil's aprons which
inhabit principally the colder seas of high latitudes. They all
grow in pools at low-water mark, attached to the rocks and in
deep water, and some attain a very large size. The species vary
greatly in outline and habit according to the season and place of
growth — whether on an exposed or sheltered coast or partly ex-
posed at low tide. It consists of three parts (Fig. 14, A) : a
long, leaf-like expansion or blade supported by a more or less
cylindrical stalk or stipe, which in turn is attached to the rocks
by a hold-fast made up of a cluster of fibrous outgrowths. In
general the species may be classed in two groups, one in which
the frond is ribbon-like or long in proportion to the breadth and
not split up into segments, and the other in which the frond is
proportionally broader and fan-shaped and laciniate. To this
latter belongs the Laminaria digitata. There are some 25 species,
distinguished by the arrangement of root-fibres comprising the
hold-fast, the structure of the stipe, whether solid or hollow and
whether provided with distinct cavities containing mucilage, the
shape, especially of the basal portion of the lamina, and the char-
acter of the margin and the position of the fruit. The growing
portion of the lamina is at the base, as in the leaves of the Spermo-
phytes. The kelps of the Pacific Ocean are among the largest
sea-weeds known, the Giant Kelp, Macrocystis, attaining a length

PRINCIPAL GROUPS OF PLANTS. 31

of nearly a thousand feet. Other forms have large floats at the
base of the lamina. Reproduction is chiefly by zoospores formed
in i -celled sporangia which occur either in dispersed patches
or in continuous bands near the centre of the frond.

SARGASSUM, or Gulf Weed, grows attached to rocks by means
of disk-like hold-fasts (Fig. 14, C). When it is torn from the rocks
it is carried into the open ocean by currents such as the Gulf
Stream. Sargassum is most highly organized and is represented
by a very large number of species. They are found especially in
the warmer waters near Australia, Japan and the adjacent coast of
Asia, and also in the West Indies and at various parts of the
Atlantic Coast near the Gulf Stream, some occurring as far north
as Cape Cod. The plants vary from 15 cm. to nearly 2 metres in
length, and consist of a stem-like axis which bears leaf-like
branches with a distinct midrib, berry-like air sacs on stalks, and
reproductive branches or receptacles.

RHODOPHYCE^E. — This includes all the Algae which are of a
reddish or violet color. They contain chromatophores in which,
the chlorophyll is masked by other pigments, mostly red, and
known as phycoerythrin or rhodophyll. The red Algae are mostly
found in salt water, occasionally in fresh and running water.
They are usually found growing upon other plants or variously
attached to some substratum. They vary from microscopic forms
or very delicate filamentous types to large plants. They are
usually composed of a number of cells or filaments which are
so closely arranged as to resemble the tissues of higher plants.
Many of the cells are connected by strands of protoplasm, giving
them a rather characteristic appearance. Others have an in-
crustation of lime on the wall. They are mostly found in deep
waters of the Tropics. Reproduction is almost entirely by sexual
or asexual spores.

CHONDRUS, or Carragheen or Irish Moss (Figs. 15, 16), is a
common rock-weed found at low-water mark, and in this country
is common from New York northward, being extensively col-
lected at a few points about 15 to 20 miles south of Boston. The
plant varies considerably in color, being more or less green when
close to the surface of the water and of a deep purplish-red when
growing at some depth. It varies from 4 to 15 cm. in length, and

32 A TEXT-BOOK OF BOTANY.

is attached to rocks by means of a slender hold- fast. The thallus
is dichotomously branching, somewhat flattened, but may be quite
linear. The fronds show a mucilaginous modification of the cell-
walls. In the upper segments occur small differentiated areas,

FIG. 15. Specimen of Chondrus crispus still attached to the rock where it was found
growing along the Massachusetts coast.

sometimes called sori, of a more or less elliptical outline, which
on sectioning are found to be in the nature of sporangia, contain-
ing numerous tetraspores (Fig. 16). The spores are discharged
through narrow canals extending through the more or less com-
pact outer layer of the frond. The article found in commerce has
the color removed by being bleached through the action of the sun

PRINCIPAL GROUPS OF PLANTS!

33

and dews. It shows, however, all the morphological structure of
the growing plant.

FIG. 16. Chondrus crispus: A, B, C, D, various forms of thallus; H, hold-fast; F,
sporangia; T, transverse section of thallus showing epidermis (E), sporangium with spores
(F) ; S, spores separated in glycerin preparation of thallus by pressure on the cover-glass.
The spores occur in groups of four (tetraspores) and the tetrad group is about 30^ in diameter.

In a closely related genus, Gigartina (Fig. 17), which is found
in imported Chondrus, the fruit bodies occur in numerous cylindri-
3

34 A TEXT-BOOK OF BOTANY.

cal outgrowths developed on the surface of the fronds. This
form is found more abundantly north of Boston than south, but,
as Chondrus is collected at Cohasset, Scituate, and other towns
south of Boston, it is not seen in commerce in this country.

RHODYMENIA, or Irish Dulce, is one of the commonest red
sea-weeds in the North Atlantic Ocean, usually growing with Fucus,
Laminaria, and other Algae between tide marks and extending
into deep water. The fronds are purplish-red, flat, membra*

FIG. 17. Gigartina mamillosa, a red sea-weed closely related to Chondrus crispus,
showing a dichotomously branching thallus and bearing at the upper part numerous cylin-
drical outgrowths in which the fruit bodies (sporangia) are found. — After Kutzing.

naceous, 15 to 30 cm. in length, irregularly cleft, palmate or
dichotomous, the margin often being marked with numerous
small divisions. The sporangia occur in scattered patches im-
mersed in the cortical tissues of the frond. It is a common article
of commerce and is said to possess anthelmintic properties.

AGAR-AGAR is derived from several of the marine Algae grow-
ing along the eastern coast of Asia, notably species of Gracilaria,
Gelidium, and Gloiopeltis. It is a mucilaginous substance which
is extracted from the sea-weeds, and is used extensively as a

PRINCIPAL GROUPS OF PLANTS.

35

culture medium in bacteriology and in other work where a nutrient
is desired. It occurs commercially in bundles 4 to 6 decimetres in
length, consisting of thin, translucent, membraneous, agglutinated
pieces, yellowish-white in color. It is usually brittle, but becomes
tough when moistened. It is used in medicine in the powdered

FIG. 18. AracTinoidiscus Ehrenbergii, a characteristic Diatom found in Agar-agar. — From
a photomicrographic negative by J. J. Woodward, Surgeon, U. S. A.

form. Under the microscope Agar-agar frequently shows the
frustules or siliceous cell walls of diatoms, which are disk-shaped
(Fig. 18). It is insoluble in cold water, but dissolves slowly in
hot water. Upon boiling I part in 100 parts of water it should
yield a stiff jelly upon cooling.

Diatoms constitute a large group of unicellular plants, occur-

36 A TEXT-BOOK OF BOTANY.

ring in both fresh and salt waters. They form the plankton or
floating microscopic life found in oceans and lakes, which is the
source of food of small animal forms inhabiting these waters.
The mud at the mouths of many rivers, the sediment of ponds,
ditches, and even rain troughs may contain great numbers of
these minute organisms. They have been found in the polar
ice, and have been detected in the dust evolved from volcanoes.
One of the distinguishing characters of the group is that the cell
wall is incrusted with silica. For this reason they are practically
indestructible and form marls and strata in the earth. They occur
either singly or grouped in bands or chains. They are very
variable in shape, being boat-shaped, ellipsoidal, spherical, or
peculiarly curved in some forms. They are either free or attached
to a substratum, as stones, water plants, etc., those which are
free having an active movement (Fig. 19).

The cell wall of Diatoms practically consists of two halves, one
fitting over the other like the lid of a box. These are known
as " valves " or " theca." The manner in which the two valves
are joined results in the formation of a " girdle " or " pleura."
The girdle is provided with a series of pores conecting with
canals at either end and in the middle, through which food from
without is supplied to the protoplast. The valves are very often
beautifully marked by a series of parallel cross lines, dots, cir-
cles, or polygons, which are characteristic of the different groups.
Some forms are used in testing the definition of objectives, as
Pleurosigma angulatum, in which the lines are one-half micron
(0.0005 mm.) wide (Fig. 19, A).

In the Diatoms the protoplasm lies as a thin layer close to the
wall surrounding a large central vacuole. The nucleus is sur-
rounded by a relatively dense mass of cytoplasm, and occurs in
definite positions according to the species. The chromatophores
frequently occur in plates which are typical for certain species.
They are sometimes greenish-yellow, the color being generally
masked by the presence of a brown substance known as diatomin.
They frequently contain pyrenoids, which are sometimes asso-
ciated with granules of starch.

Reproduction takes place by simple division or fission, the two
valves separating and a new valve forming on each half to replace

PRINCIPAL GROUPS OF PLANTS.

37

the old one. In each case the valve formed fits into the old one,
and hence in the case of the smaller valve the new cell or plant
becomes smaller than the parent plant, the walls not being able
to expand on account of the siliceous composition. In this way
the cells of one series gradually becomes smaller and smaller until
a certain minimum is reached, when the plant rejuvenates itself

FIG. 19. Diatoms: A, Pleurosigma attenuatum as seen from above; B, Pleurosigma
baUicum as seen from the girdle side; C, D, E, Fragilaria virescens showing colonies attached
to an alga in C, a view of a single diatom from above at D, and a chain of diatoms viewed
frorr the girdle side at E; F, G, two views of Navicula viridis; H, I, the formation of auxo-
spores in Navicula firma, H showing the exit of the protoplasts and the throwing off of the
original valves. — A, B, D, after Van Heurck; C, E, after W. Smith; F-I, after Pfitzer.

by the production of spores (auxospores). These are formed in
two ways: In one case the valves separate from each other, the
protoplast escapes, grows larger and develops a new wall ; in the
other case, of which there are several types, two individuals come
together, and envelop themselves in a mucilaginous covering.
They then throw off their siliceous walls and the protoplasts
unite to form a zygospore, which grows until it is three times the

38 A TEXT-BOOK OF BOTANY.

original size, after which it develops a new wall, the larger valve
forming first (Fig. 19, H, I).

DIATOMACEOUS EARTH, also known commercially as " In-
fusorial Earth," or " Kieselguhr " (meaning siliceous marl),
occurs in extensive deposits, some of these, as the stratum at
Richmond, Va., extending to a depth of 18 feet. These deposits
consist of the siliceous walls of the Diatoms, which, owing to their
composition, are practically indestructible, and are accumulated
in those localities which have favored the growth of the organ-
ism. The natural deposit is mined and usually calcined to de-
stroy the organic matter, after which it is washed and dried.
The article used in pharmacy is further purified by boiling with
diluted hydrochloric acid, washing, and calcining. This purified
product is known as Terra Silicea Purificata, and occurs in the
form of an almost whitish, or light grayish, or light brown powder.
It is odorless, insoluble in water and in mineral acids or dilute
solutions of the alkalies. Under the microscope mounts made in
water or solutions of hydrated chloral show the frustules or
siliceous walls of the Diatoms. In the better grades of Diatoma-
ceous Earth the entire skeleton with the characteristic markings is
present. Material coming from various localities shows a differ-
ence in genera of Diatoms. The exact naming of the species
requires the assistance of specialists. In order to avoid confusion
it is necessary to bear in mind that there are two and sometimes
even three views which may be obtained of the same Diatom.

Diatomaceous Earth consists of about 85 per cent, of SiO2,
10 per cent, of water, and 5 per cent, of clay, iron oxide, magnesia,
lime, and organic material. Owing to the fact that Diatomaceous
Earth is made up of the hollow shells of Diatoms, it has the
property of absorbing by capillarity gases and liquids. For this
reason it is used in the preparation of dynamite ; the highly ex-
plosive nitroglycerin being absorbed by the diatomaceous shells,
render-ing the product capable of being handled. When calcined,
it will absorb its own weight of water. It is used in pharmacy for
filtering and as a diluent for powdered extracts, etc. Among the
technical uses may be mentioned : polishing of metals and woods,
insulating steam pipes and electrical insulators, packing of caustic
and inflammable liquids, and the manufacture of glass, paper, and

PRINCIPAL GROUPS OF PLANTS.

39

soap. It is also used to some extent in dermatology. In India it
has been used as a rubefacient. In Sweden, and among the
Chinese and Laplanders, Diatomaceous Earth has been used as an

FIG. 20. The Algae are put to various uses by the people who collect them. The
illustration is taken from an ornament purchased at the Louisiana Purchase Exposition
and was made by the Filipinos from various kelps having large, bladder-like floats.

edible earth under the name of " mountain meal " or " bread-
stone.'' Humboldt also calls attention to the fact (Aspects of
Nature) that the practice of eating earth is diffused throughout
the torrid zone, among indolent races inhabiting the finest and

40 A TEXT-BOOK OF BOTANY.

most fertile parts of the globe. It is a saying even among the
most distant of the different tribes living on the Orinoco, when
speaking of anything very unclean, that it is " so dirty that the
Otomacs eat it."

ECONOMIC USES OF ALGJE. — Many of the Algae are of use as
food, of which the following may be mentioned : Vaucheria fasti-
giata, Griffrthsia coralina, Ceramium Loureirii, Chondrus crispus,
Gigartina mamillosa, Gelidium cartilagineum, Gelidium crinale
(yielding agar-agar), Rhodymenia palmata (yielding dulse), and
several species of Gracilaria (which also yield agar-agar).

Some of the sea-weeds are used in the production of iodine,
as Durvillcca utilis, Ascophyllum nodosum, Fucus vesiculosus
(bladder-wrack), Sargassum linifolium, Laminaria saccharina,
Laminaria digitata, Alaria esculenta, Rhodymenia palmata, Phyl-
lophora membranifolia, Macrocystis pyrifera, and Fastigiaria
furcellata.

A number of the Algae are also used in medicine, particularly
for phthisis, as Fucus cartilagineus} Stilophora rhizodes and
Dictyopteris polypodioides. Alaria esculenta and Laminaria digi-
tata are used in the making of bougies and tents used in surgery.
Owing to the toughness of some of the Algae on drying, the
material is used in the manufacture of various articles, as handles
for tools from the thick stem of Lessonia jucescens, fishing lines
from Chordaria flagelliformis (Fig. 20), etc.

FUNGI.

The Fungi form a large group of plants which do not produce
chloroplasts or any bodies having a similar function. They have
not the power of carbon dioxide assimilation, — that is, unlike the
Algse, they are unable to manufacture food materials, such as
carbohydrates (starches, sugars, etc.), from carbon dioxide and
water. Hence they are dependent upon previously formed food
products, and may derive their food from living plants or ani-
mals, when they are known as PARASITES, or from decaying animal
or vegetable matter, when they are known as SAPROPHYTES. The
living plant or animal atacked by a fungus is known as the host.

Fungi are especially characterized by the habit of arising
from spores and of producing thread-like cells the growing point

PRINCIPAL GROUPS OF PLANTS. 41

of which is at the apex. These threads are known as HYPH;E
(singular hypha). They branch and become interwoven, forming
a mass or mat known as the MYCELIUM (Fig. 23). The myce-
lium constitutes the plant body proper, and absorbs the food
material from the substratum, which it ramifies, often causing
decay. The mycelium is frequently not visible, and the presence
of the fungus is not recognized until the so-called fruit bodies are
developed, as sometimes seen in the case of moldy oranges,
mildewed linen, and as illustrated by the common mushroom.
The mycelium has a cellulose wall which in some cases is modi-
fied to chitin, a nitrogenous substance related to animal cellulose
and found in crabs and other lower animals. The protoplasm
either occurs in a more or less delicate form lining the hyphse and'
enclosing large vacuoles, or is comparatively dense enclosing
numerous small vacuoles. Many Fungi contain color substances
which are dissolved in the cell-sap and are of a quite brilliant hue.
One of the most interesting classes of substances produced by
Fungi is that of the ferments, including the oxidizing ferment
allied to laccase. They contain also amido-substances related to
lecithin ; fats ; carbohydrates, as trehalose and mannitol ; organic
acids, as oxalic, tartaric, malic, etc. ; and calcium oxalate may
be present in some cases.

Reproduction in the Fungi is chiefly by means of asexual
spores, which arise in two ways. In the one case they are devel-
oped in a special cell or sporangium at the end of a mycelial thread
and are known as ENDOSPORES. In the other case they arise on
special hyphse, or directly from the mycelium, and are known as
EXOSPORES or conidia. There are also several modifications of
these two types .of spores, which may be referred to later.

Groups of Fungi. — There are four principal groups of Fungi :

1. Phycomycetes.

2. Basidiomycetes.

3. Ascomycetes.

4. Fungi Imperfecti.

The Phycomycetes, or Algal-like Fungi, are so called because
they show a certain relation to the Algae.

The Ascomycetes are distinguished by having a sporangium of

42 A TEXT-BOOK OF BOTANY.

a definite shape and size, which is called an ASCUS, and which
contains a definite number of spores, which is two or some multi-
ple thereof.

The Basidiomycetes are the most highly developed Fungi,
producing large fruit bodies, such as are seen in mushrooms, toad-
stools, and puffballs. They are characterized by producing spores
(basidiospores) on special hyphae. The spores are usually four
in number, and the spore-producing organ is known as a BASIDIUM.

The Fungi Imperfecti constitute a group of Fungi which,
while having certain natural relationships with the other types
already considered, yet do this so imperfectly that they are brought
in a class by themselves. The complete life-cycle is not in all cases
known, and future studies will probably distribute them among
the other principal groups.

PHYCOMYCETES : ALGA-FUNGI— The plant body of
the Phycomycetes consists of a mycelium which is unsegmented,
more or less thread-like and sometimes considerably branched.
Reproduction takes place by means of several kinds of spores, and
by reason of the production of two kinds of sexual spores they are
subdivided into two important groups. These are ( I ) the Oomy-
cetes, which produce oospores, and (2) Zygomycetes, which
produce zygospores.

Saprolegnia. — Probably one of the best representatives of
the Oomycetes is the group of water molds known as Saproleg-
nia, which are aquatic in their habits and are both parasitic and
saprophytic, occurring on living fish, insects, crayfish and decay-
ing plants and animals as well. The plant body consists of a
mycelium which may be simple or branched, sometimes forming
a dense mass (Fig. 21, A). Like the alga Vaucheria, it produces
both swarm spores (zoospores) and oospores. The swarm spores
(Fig. 21, B, C) are produced in sporangia formed by the pro-
duction of a partition wall at the end of a hypha. The sporangia
are either cylindrical or spherical, and contain numerous zoospores
which have two cilia at one end. These spores are peculiar in
that after their escape from the sporangium they swim about,
then come to rest and take on a wall, after which resting period
they develop two cilia on the side, again move about, and germi-
nate when they find a suitable host.

PRINCIPAL GROUPS OF PLANTS.

43

The oogonia and antheridia (Fig. 21, D-F) are also formed
at the ends of hyphse. The oogonia are usually spherical and the
wall contains a number of small pores. The contents, which are
at first more or less uniform, later develop egg-cells, of which
there may be as many as fifty in a single oogonium. The anthe-
ridium is more or less cylindrical and contains a somewhat uni-

F

FIG. 21. Species of Saprolegnia: A, mycelium growing out from and surrounding
a dead house-fly in a water culture; B, C, sporangia with biciliate swarm spores; D, a num-
ber of oogonia containing oospheres; E, F, oogonia and antheridia, in F the tube of the
antheridium having penetrated the oogonium.— A-C, after Thuret; D-F, after De Bary.

form mass of protoplasm. The antheridium bends toward the
oogonium and comes in contact with it, but apparently does not
in all cases penetrate it. Nevertheless the egg-cells develop walls
and become resting oospores.

In Peronospora, one of the Oomycetes, the antheridium
(Fig. 22, n) develops a tube which pierces the wall of the

44

A TEXT-BOOK OF BOTANY.

oogonium (Fig. 22, o) ; the contents unite with the egg-cell,
after which a heavy membrane develops, forming an oospore,
which germinates when it finds a suitable host. The plants
belonging to Peronospora as well as related genera are destruc-

FIG. 22. A, Cyslopus candidus; B, Peronospora calotheca. Mycelia (m) with haustoria
penetrating cells (z) of hosts. C, Oospore formation in Peronospora: o, oogonium; n, anthe-
ridium. At the left the antheridium is in contact with oogonium; the next stage shows the
antheridium penetrating oogonium and discharging its contents; at the right the resulting
oospore is shown. — After De Bary.

tive to many cultivated plants, constituting mildews or blights,
as those occurring on the leaves of hyoscyamus, tobacco, anthe-
mis, matricaria, aconite, grape vine, lima bean, potato, etc. The
group has received the name "downy mildews " because of the

PRINCIPAL GROUPS OF PLANTS.

45

fact that the conidiophores rise to the surface of the leaves
where the spores are discharged, forming powdery patches.

Black Mold. — A common example of the Zygomycetes is
furnished by the " black mold," Mucor Mucedo. The mycelium

FIG. 23. B, richly branching mycelium (m) of the mold Phycomyccs nitens showing
upright hyphae bearing sporangia (g). A, C, D, the common black mold Mucor Mucedo.
A, sporangium with columella; C, germination of zygospore (z), with formation of hypha
(k), and sporangium (g); D, earliest stages in the development of a zygospore, the hyphal
branches (b) showing adjoining ends (a) cut off by cross walls. — After Sachs.

of this plant is ccenocytic, thread-like, very much branched, arid
profusely developed, much like that of Phycomyces nitens (Fig.
23, B). This mold is widely distributed, causing trouble in the
spoiling of many sugar- and starch-containing substances in the
household, including preserves, syrups, fruits, etc. In fact, a

46 A TEXT-BOOK OF BOTANY.

number of species of Mucor have the power of inducing alcoholic
fermentation in glucose-containing solutions. They are also
commonly found in many aqueous solutions of inorganic chemicals
as well as organic substances. Asexual spores are formed at the
ends of hyphae which rise into the air. The sporangia are spherical
and are cut off from the hyphae by means of a transverse wall
which projects upward into the sporangium and which is techni-
cally known as the columella (Fig. 23, A). The contents by

FIG. 24. Peziza confluens showing stages in the development of ascospores. In the
youngest asci (m, r) there is only one nucleus; this divides into two (s^; the division is
repeated, so that there are 4 nuclei in (t) and 8 in (n). These surround themselves with
protoplasm and a cell-wall (v, w), but the protoplasm of the mother cell or ascus is not entirely
used up. — After De Bary.

simultaneous division form numerous I -celled spores, which are
discharged by the bursting of the sporangium wall and distributed
by air-currents or the wind. As the name of the group to which
this plant belongs indicates, it also produces zygospores (Fig.
23, £>). These are formed by hyphal branches which ascend
from the substratum. The ends of two branches come together,
a transverse wall is formed in each branch, the walls in contact
are absorbed, the contents unite, and a spore is formed with

PRINCIPAL GROUPS OF PLANTS.

47

three membranes, two belonging to the spore proper and the third
being formed by the united hyphae. As would be expected, these
spores are quite resistant, being able to withstand unfavorable
conditions, and germinate (Fig. 23, C) only after a period of rest.
ASCOMYCETES. — The Ascomycetes are distinguished for
the most part, like the other higher Fungi, in having a septate
mycelium, i.e., one cellular in structure, and in producing asci

FIG. 25. Species of Saccharomyces (Yeasts). A, 5. cerevisice or beer yeast; B, S.
Pastorianus; C, S. glomeratus; D, S. Piculatus: a, vegetative cells reproducing by budding;
b, formation of ascospores. — After Reesz.

(sacs), which latter are formed at the ends of the branches of
the mycelia. Two main sub-groups are recognized, the one
producing an indefinite number of spores in asci which are not
well developed, and known as the HEM i ASCI ; the other producing
la definite number of spores, which number is characteristic for
each species, in a well-developed ascus, and known as the EUASCI.
In the latter group the spores arise by successive divisions of the
primary nucleus into two, as shown in Peziza confluens (Fig. 24).
Yeasts. — The simplest of the Ascomycetes is the sub-group
known as the Saccharomyces, or Yeasts. The Yeasts do not
produce a mycelium, but the plant body consists of a single cell,
or a chain of cells, and multiplies by a peculiar process known
as "yeast budding" (Fig. 25, a). From either end of the cell
a wart-like process develops, which enlarges until about the size

48 A TEXT-BOOK OF BOTANY.

of the original cell, from which it is then separated by the forma-
tion of a transverse wall. The cells are spherical, ellipsoidal, or
egg-shaped, and in some cases somewhat elongated and hypha-
like. In the protoplasm are one or more large vacuoles. In
certain of the cells, which may be considered to be asci, two to
eight spherical or ellipsoidal spores are produced (Fig. 26).
There are a number of different species of Yeasts, some of which

FIG. 26. Formation of ascospores in a number of different species of Yeasts. I, Sac-
charomyces cerevisice; 2, S. Pastorianus; 3, 5. intermedius; 4, 5. validus. — After Hansen.

are cultivated ; and these latter are of great economic importance
on account of their property of inducing alcoholic fermentation.
They are also of use in the making of bread, changing the carbo-
hydrates in part into carbon dioxide and alcohol, both of which
are driven off in the baking.

The property of yeast causing the fermentation of a solution

PRINCIPAL GROUPS OF PLANTS. 49

of sugar whereby alcohol is formed, was for a long time supposed
to be due to the presence of the living yeast cell or to the action
of living yeast protoplasm, and hence fermentation brought about
by living organisms was distinguished from those fermentative
processes where distinct principles such as diastase were involved ;
the former being known as " organized " ferments, while the
latter were referred to as " unorganized " ferments. Biiclmer
obtained from freshly expressed yeast a nitrogenous substance
capable of changing solutions of cane sugar or glucose into alcohol
and carbon dioxide. This principle he termed zymase, and it
has all of the properties of an enzyme or ferment and behaves
exactly as the living yeast cell in a sugar solution. In the living
yeast plant zymase is continually being formed and decomposes the
sugar which has diffused into the cell.

Yeasts are used in the treatment of certain skin diseases, their
action being attributed to a fatty substance, ceridine. Other
principles found in yeasts as well as extracts are used in the
treatment of cancer.

Under the name of Xerase a mixture is marketed consisting
of 150 parts of dried beer yeast, 20 parts of dextrose, 125 parts
of white clay or aluminum silicate, and 3 parts of a mixture of
nutritive salts. It is used in the treatment of putrid wounds,
ulcers, etc.

The ginger beer plant, which is used in England for making a
beverage known as ginger beer, consists of a yeast (Saccharo-
myces pyriformis) and a bacteria (Bacterium vermiforme) .
These two organisms live in a somewhat symbiotic relationship, the
yeast changing the sugar into alcohol and the bacteria developing
lactic acid (see Technical Mycology, by Lafar).

Green and Yellow Mildews. — To the Ascomycetes also be-
long the green and yellow Mildews, Penicillium and Aspergillus,
so common in the household, the dairy, and the granary. These
plants produce profusely branching mycelia which form patches
upon or just under the surface of the materials upon which they
grow. These areas become soft and spongy and are always white
at first. After a time hyphal branches, which are more or less
flask-shaped, rise above the substratum, and by a process of
division at the end of the branch, or conidiophore, a spore called
4

5o A TEXT-BOOK OF BOTANY.

a conidiospore is formed (Fig. 27, A; Fig. 28, A). The process
of division at the end of the conidiophore continues from below
until a chain of conidiospores is formed. The conidiophore fre-
quently branches, so that a fan-like series or group of conidia or

FIG. 27. Penicillium, a green mildew. A, richly branching mycelium with conidio-
phores; B, enlarged view of conidiophore showing chains of conidia; G, D, E, F, successive
stages in the development of a perithecium; G, H, J, development of asci; K, groups of
asci containing from 4 to 8 ascospores; L, ascospores seen from the side and showing char-
acteristic markings. — After Brefeld.

conidiospores is produced (Fig. 27, B; Fig. 28, A). The conidia
are usually some shade of green, but finally they may become more
or less brown. They are thin-walled, quite small, and so light
that they float freely in the air. If a colony is inhaled it gives

PRINCIPAL GROUPS OF PLANTS. 51

the sensation commonly called the " smell of mold." They are
capable of germinating on almost everything, as old shoes, old
paper, as well as on bread and other articles of the household, and
are commonly found on " moldy drugs," and may occur in pharma-
ceutical preparations, as syrups and infusions, and even in solu-
tions of inorganic as well as organic chemicals.

Aspergillus (Fig. 28) is distinguished from Penicillium (Fig.

FIG. 28. Aspergillus. a yellow mildew. A, conidiophore with enlarged, more or less
spherical end, from which the fan-like series of chains of conidia arise; B-E, successive
stages in the development of perithecium; F, section through a nearly ripe perithecium;
G, groups of young asci; H, a ripe ascus with 8 spores. — A, after Kny; B-H, after De Bary.

27) by the fact that the upper end of the hyphal branch or conidio-
phore is somewhat enlarged and more or less spherical.

In addition to the conidiospores these Fungi sometimes produce
in the fall of the year, particularly when grown upon bread, asci
fruits (Fig. 27, C-F; Fig. 28, B-E}. In this case two fertile ini-
tial hyphae wind themselves around each other, after which they
become surrounded with sterile branches which form a kind of

52 A TEXT-BOOK OF BOTANY.

loose tissue, more or less cellular in structure, that finally develops
into a yellowish leathery wall. This body, which may be regarded
as a closed ascocarp, is known as a perithecium (Fig. 27, F; Fig.
28, F). As a result of the conjugation of the fertile cells, asci
(Fig. 27, G, H, J ; Fig. 28, G, H) develop within the perithecium,
which are more or less spherical or ellipsoidal and contain from
four to eight spores (ascospores) (Fig. 27, K; Fig. 28, H).
After maturity the cellular tissue around the asci dries up and dis-
integrates, the walls of the asci dissolve, and the ascospores are
liberated from the perithecium by slight pressure. The spores
lie over winter and then germinate, producing a mycelium from
which conidia first develop and afterwards the perithecia, thus
repeating the life history of the plant.

Ergot. — Another Ascomycete of special interest is the fungus
known as Ergot (Clamceps purpurea). The spores of this
fungus germinate on the flowers of certain grasses. The myce-
lium penetrates the walls of the ovary, absorbing the nutriment.
After a time the mycelium develops on the surface, and from
this short conidiophores arise bearing small ovoid conidia (con-
idiospores) (Fig. 29, A). The mycelium secretes a sweet fluid,
the so-called honey dew which attracts insects, and thus the
conidia are carried to other plants. As the conidia are capable of
immediate germination the so-called " ergot disease " rapidly
spreads during the flowering season of the host plants. After the
formation of conidia ceases, the mycelium forms a dense mass
which is surrounded by a dark layer, and this, if developed upon
rye, constitutes the ergot grains (Fig. 29, B) used in medicine,
these grains being a number of times larger than the rye grains
which they replace. The mycelial tissues connected with the host
plant die, and the ergot drops to the ground. At this stage the
ergot mass is more or less cellular in structure and is known as the
SCLEROTIUM. It is quite resistant and usually remains dormant
until the following spring when the grasses are in flower again.
The sclerotium then shows signs of renewed activity by the de-
velopment of small, reddish, spherical bodies with a fair-sized
stalk (Fig. 29, C). Within the periphery of these spherical heads
are produced flask-shaped perithecia or ascocarps (Fig. 29, D)

PRINCIPAL GROUPS OF PLANTS.

53

containing numerous cylindrical asci (Fig. 29, E), each of which
contains eight spores (Fig. 29, F) ; the latter are i -celled, hya-
line, and thread-like (Fig. 29, H ). These spores are carried by

J) '

FIG. 29. Claviceps pur pur ea. A, mycelium developing conidia; B, an ear of rye
with a number of lipe sclerotia replacing grains of rye, and known as ergot; C, sclerotium
developing spherical fruit bodies; D, fruit body in longitudinal section showing numerous
flask-shaped perithecia at the periphery; E, enlarged perithecium with numerous cylin-
drical asci; F, closed ascus with 8 ascospores; G, discharge of ascospores; H, single thread-
like ascospore. — A, after Brefeld; B, after Schenck; C-H, after Tulasne.

the wind to the flowers of certain of the grasses, as already stated,
and the life history or cycle of growth begins again.

54

A TEXT-BOOK OF BOTANY.

Chestnut Bark Disease is caused by a fungus parasite known
as Diaporthe parasitica Murrill, and is said to very closely re-
semble the parasite found in Italy, Endothia radicalis. This
fungus has been the cause of very great destruction of chestnut
trees in the eastern United States. When any of the spores of
this fungus gain entrance into a wound on any part of the tree,
thread-like mycelia are developed in the inner layers of the bark,
and these spread concentrically until they girdle the trunk or

FlG. 30. Large Chestnut tree partly killed by the bark disease. Note branches
in the center either killed or bearing dwarfed leaves, and the other larger branches still
unaffected. — From photograph by Haven Metcalf.

limb, so that if it happens that the trunk is affected the entire tree
may die within the year, while if it is the smaller branches which
are attacked, only those parts beyond the point of infection are
killed, while the remainder of the tree will survive for some
years (Fig. 30).

When the bark is attacked by the fungus it shows minute, more
or less crater-like spots of a yellowish-orange or reddish-brown

PRINCIPAL GROUPS OF PLANTS

55

color which are pustules of the fruiting fungus. These pustules
produce mostly winter spores (ascospores), although occasionally
a long strip of summer spores (conidia) are also produced (Figs.
31 and 32).

FlG. 31. Typical appearance of branches of Chestnut tree affected with chestnut
blight. At left, bark showing pustules of the parasitic fungus bearing winter spores. At
right, the diseased bark showing pustules and form of discharge of summer spores in damp
weather. — From photograph by Haven Metcalf.

The control of the disease over large districts consists mainly
in destroying the affected trees and carefully burning the rubbish.

56 A TEXT-BOOK OF BOTANY.

Single trees are treated by removing the affected branches and
painting over the cut ends with coal tar to prevent reinfection.

For further details on this fungus consult : Murrill, " A New
Chestnut Disease," Torreya, Sept., 1906; Farmers' Bulletin 467,
U. S. Department of Agriculture; Metcalf, -" Diseases of the
Chestnut and Other Trees," Trans. Mass. Hort. Soc., August,

FIG. 32. Chestnut-blight disease, which occurs in small yellowish pustules the size
of a pin head. A, section of pustule showing perithecia; B, asci with sporidia; a, usual
form; b, form rarely found; C, sporidia; D, summer spores.— After Murrill.

1912; Farlow, "Fungus of the Chestnut-Tree Blight," Science,
May 10, 1912.

BASIDIOMYCETES. — The Basidiomycetes are the most highly
organized of the Fungi. The mycelium consists of white branch-
ing threads and is usually concealed in the substratum. In the
cultivation of the edible mushrooms propagation is by means of
the mycelium, which is known commercially as " spawn." It is
recognized, however, that mushrooms can not be propagated in

PRINCIPAL GROUPS OF PLANTS.

57

this way exclusively for more than two or three years. The my-
celium is really the plant body, and the part which rises above the
surface and is commonly regarded as the toadstool or mushroom
(Figs. 33 to 37) is a fruit branch, or spore-producing organ.
When these branches first make their appearance they are in the
form of small solid bodies known as " buttons " (Fig. 33, I-V).

J

FlG. 33. Agaricus campestris, the common edible mushroom, showing at A on the
left mycelium (m) and development of buttons or young mushrooms; I to V, longitudinal
sections showing successive stages in development of fruit body; m, mycelium; st, stipe;
h, portion between veil (v) and spore-bearing portion (1).

The illustration to the right (A, B, C) shows the structure of the hymenium in different
degrees of magnification: A, section through portion of pileus showing five of the gills;
B, section of a gill somewhat magnified; C, section of gill still more magnified and showing
sterile cells or paraphyses (q), and the fertile cells or basidia (s), from each of which arise
two basidiospores. — After Sachs.

As growth proceeds these bodies differentiate into a stalk-like
portion known as the stipe (Fig. 33, st), which is directly con-
nected with the mycelium, and an umbrella-like portion borne at
the summit of the stalk, called a pileus, which at first is closed
down over the stalk, but later expands or opens more or less
widely according to the species. On the under surface of the
pileus, known as the hymenium, the spores are borne (Fig. 33,

(58

A TEXT-BOOK OF BOTANY.

FIG. 34. Some common edible mushrooms and a common poisonous one. The fol-
lowing are edible: i, Common Field mushroom (Agaricus campestris); 3, Clavaria flava,
young plant; 6, Puffball (Lycoperdon cyathiforme) ; 4, Morel (Morchella esculenta); 5,
Chanterelle (Cantharellus cibarius); 7, Fairy-ring Fungus (Marasmius oreades).

Only one poisonous species is shown, namely, 2, the deadly Agaric (Amanita phalloides).
— Adapted from Farlow.

PRINCIPAL GROUPS OF PLANTS. 59

A, B, C). In some cases the under surface is composed of
a series of narrow, radiating, knife-like plates, or gills, as in
the common edible mushroom Agaricus. On the surface of
the gills the basidia or spore-bearing organs arise. The basidia
are somewhat swollen terminal cells of the closely arranged hyphse
composing the gills, which bear a group of spores on short stalks
(Fig. 33, C). Both the basidia and spores (basidio-spores) are
of a characteristic size and number for the different species.

Several types of Basidiomycetes are usually recognized, de-
pending on the manner in which the spores are borne.

1. The Gill Fungi (Agaricacese), in which the spores are
borne on plates or gills which radiate from the stem to the edge
of the cap.

2. The Pore Fungi (Polyporaceae), in which the spores are
borne in tubes or pits opening by pores rather than on gills.

3. The Coral Fungi (Clavariacese), in which the Fungi are
coral-like or leaf-like, the surface of the cap or its branches being
smooth.

4. The Leather Fungi (Thelephoracese), in which the spore-
bearing surface is smooth or slightly wrinkled. The texture is
usually leathery or papery.

5. The Jelly Fungi (Tremellacese), in which the fruiting sur-
face is smooth and the cap is more or less jelly-like when wet.

6. The Puff Balls (Lycoperdacese), in which the cap is a
closed ball which breaks open at maturity to release the enclosed
spores.

7. The Carrion Fungi or Stink-horn Fungi (Phallaceae) re-
semble the puffballs when young, but are ruptured longitudinally,
the spores thereby being exposed on the top as a gelatinous mass.

Of these seven groups the Gill Fungi are the commonest, and
one or two types will be considered, namely, the common edible
mushroom and two of the poisonous group, Amanita.

Edible Fungi. — Agaricus campestris (common mushroom)
(Figs. 33 and 34) is practically the only edible species cultivated
in this country. The plant grows wild in open grassy fields dur-
ing August and September. It is not found in the mountains to
any extent, and is never found in the woods or on trees or fallen
trunks. The color of the stipe and the upper surface of the

6o

A TEXT-BOOK OF BOTANY.

FlG. 35. A decaying tree trunk showing the cause of the death of the tree by the
appearance of the several fungi (probably Amanita muscaria). It is not unusual to find
trees showing signs of disease and, finally, even dying, and it is not until the death of the
tree that the mature fungus makes its appearance. For some years the mycelium of the
fungus has been working its way into the tissues not only of the bark but of the wood,
sapping it of its vitality. When there is no longer any food supply the fungus produces
its fruit; the spores, being scattered by either the wind or through the agency of birds,
are carried to other trees and find entrance into wounds, where they germinate and repeat
their destruction. — From a photograph by Henry Troth.

PRINCIPAL GROUPS OF PLANTS. 61

pileus varies from whitish to a drab color, but the color of the
gills is at first pinkish and then of a brownish-purple, which is
an important character, the color being due to the spores. The
stipe is cylindrical and solid, and a little more than half way up
is furnished with a membranous band known as the ring. There
are no appendages at the base of the stipe, which appears to rise

FIG. 36. Edible Boletus (Boletus edulis), an excellent edible mushroom found in woods
and openings in summer and autumn. The cap is 8 to 15 cm. wide, grayish-, yellowish-, or
brownish-red, sometimes paler toward the edge, smooth, and more or less convex; flesh
whitish or yellowish, or somewhat reddish just beneath the skin; stem white, stout, and
often bulbous. — From monograph on Minnesota Mushrooms by Frederic E. Clements.

directly out of the ground. Before the pileus is fully expanded a
veil extends from its border to the stipe, which when ruptured
leaves a portion attached to the stipe, and it is this which consti-
tutes the ring. The ring shrinks more or less in older specimens,
but usually leaves a mark indicating where it has been formed.

Poisonous Fungi.— There are two of the poisonous group
of Fungi which are very common and which have some resem-

62 A TEXT-BOOK OF BOTANY.

blance to the edible mushroom just described, namely, the fly
agaric (Amanita muscaria) (Fig. 38) and the deadly agaric
(Amanlta phalloides) (Fig. 34). The fly agaric, while more abun-
dant in some localities than the common edible mushroom, is

FIG. 37. Pale Lenzites (Lenzites betulina), a non-edible fungus common on trunks
and stumps throughout the year. The cap is whitish, corky, more or less densely hairy,
and marked by concentric grooves; the stem is lacking and the gills are whitish, more or
less branched and united. — From monograph on Minnesota Plant Diseases by E. M.
Freeman.

seldom found in grassy pastures, but more generally in poor soil,,
especially in groves of coniferous trees. It occurs singly and not
in groups. The gills are always white ; the stipe is white, hollow,
and provided with a ring at the top, and the base is bulbous, hav-
ing fringy scales at the lower part. The pileus is yellow or orange

PRINCIPAL GROUPS OF PLANTS.

PIG. 38. Fly Agaric (Amanita muscaria), a very deadly mushroom. The cap is bright
red or orange, becoming yellow or even whitish in age, roughened with many thick, white
angular fragments of the volva; the stem is stout, white, scaly, bulbous, and hollow; volva
forming several concentric scaly rings on the bulb; gills free or touching, white or yellowish.
This is frequent in woodland, forest, or clearing from June to frost, and is deadly poisonous.
—From monograph on Minnesota Mushrooms by Frederic E. Clements.

64 A TEXT-BOOK OF BOTANY.

and sometimes reddish ; the surface is smooth, with prominent,
angular, warty scales, which can be easily scraped off.

The deadly agaric (Fig. 34, illus. 2) somewhat resembles the
fly agaric and also differs from the common mushroom in not
usually growing in pastures. It occurs singly, but not in groups,
in woods and borders of fields. The gills and stipe are white,
the latter, when young, having a number of mycelial threads
running through it. The base is quite bulbous, the upper part of
the bulb having a sac-like membrane called the volva. The pileus
may vary from any shade of dull yellow to olive, although some-
times it is shiny and white. -While it does not possess the warty
scales found in the fly agaric, it has occasionally a few mem-
branous patches.

The Toxic Principles in Poisonous Fungi. — The deadly
agaric (Amanita phalloides) is the cause of the greatest number
of cases of mushroom poisoning. According to Abel and Ford,
it contains two toxic principles: (i) Amanita-hemolysin, a blood-
laking principle, which is a very sensitive glucoside, — that is, pre-
cipitated by alcohol, destroyed by heating to 70° C. and by
the action of digestive ferments; (2) Amanita-toxin, which is
soluble in alcohol, is not destroyed by the action of heat or
ferments. The latter principle is the important poisonous prin-
ciple in mushroom poisoning and is probably the most toxic
principle known, 0.4 of a milligramme killing a guinea pig within
24 hours. " The majority of individuals poisoned by the ' deadly
amanita ' die, but recovery is not impossible when small amounts
of the fungus are eaten, especially if the stomach be very promptly
emptied, either naturally or artificially."

The fly agaric (Amanita muscaria) owes its toxicity to mus-
carine, an alcohol-soluble crystalline substance. It is supposed
by Ford that the fly agaric may contain another poisonous constit-
uent. In cases of poisoning atropine has been successfully ad-
ministered hypodermically in doses of y-J-g- to -£$ of a grain.

It is stated that the A. muscaria, used by the peasants of the
Caucasus in the preparation of an intoxicating beverage, is deficient
in muscarine.

The question as to whether the ordinary edible mushrooms,
as distinguished from the poisonous toadstools, may not in cer-

PRINCIPAL GROUPS OF PLANTS. 65

tain localities or at certain periods of the year be the cause of
fatal intoxication is answered by Ford in the negative. He states
(Science, 30, p. 105, July 23, 1909) that there are no authentic
cases of poisoning from the black or brown spored agarics,
although old and badly decomposed specimens may cause transient
illness.

.Economic Uses of Fungi. — A large number of the Fungi,
particularly of the Basidiomycetes, are used for food. There
are, however, only a few of these which enter the market. These
are derived chiefly from Agaricus campestris (Figs. 33 and 34)
and Agaricus arvenis, although some other species of Agaricus
as well as Morchella esculenta (Fig. 34, illus. 4) furnish excellent
products and are cultivated to a limited extent. The " truffles "
of the market are tuber-like masses formed under ground, which
consist of the ascocarps of certain Tuberacex, one of the sub-
groups of the Ascomycetes, and which are used as a condiment
and sometimes roasted like potatoes. Tuckahoe or " Indian
bread " is also produced under ground and consists apparently
of the fungus Pachyma Cocos and the roots of Liquidambar, the
tissues of which have been changed into a compound resembling
pectic acid by the fungus. Quite a number of Fungi have been
used in medicine, as Claviceps purpurea (Fig. 29), Polyporus
officinalis and other species, and various species of Lycoperdon.
A number of species are used in making surgeon's agaric (Fungus
chirurgorum) formerly used as a haemostatic, including Lycoper-
don Bovista and Polyporus fomentarius. Many of them yield very
toxic principles, as ( i ) several species of Amanita which contain
several toxic principles; (2) Lactarius piperatus and others
which yield highly poisonous resinous principles. Other uses of
Fungi have been mentioned under the several groups.

USTILAGINE^: and UREDINE^. — There are two groups of
Fungi of considerable economic interest which by some writers
are classed by themselves, and by others placed with the Basidio-
myretes. These are the Ustilaginese, or Smut Fungi, and the
Uredinese, or Rust Fungi.

The Smut Fungi are parasitic on higher plants. The myce-
lium penetrates the tissues of the host, but does not seem to
cause either disease or malformation of the plant. Injury to the
5

66

A TEXT-BOOK OF BOTANY.

host results only after the development of resting spores. The
mycelia are hyaline, more or less branched, and finally become
septate. They send short branches, called haustoria, into the
cells of the host, from which they obtain nourishment. Eventu-
ally the mycelium becomes much branched, compact and more or
less gelatinous through a transformation of the hyphal walls,
forming gall-like swellings or blisters on the host. Spores are
formed within this gelatinous mass at the ends of the branches

.FlG. 39. Corn smut (Ustilago Maydis) showing several gall-like masses of smut full

of spores.

of the mycelium. At a later stage the smut loses its gelatinous
character, the mass breaks up, and the spores are freed and dis-
tributed as a dry, dusty powder. The spores (primary conidia)
are somewhat spherical or ellipsoidal, and are generally separate,
but are sometimes united into a mass forming the so-called " spore
balls." These are resting spores and upon germination (Fig. 40)
produce a promycelium or basidium which becomes septate and
from each cell of which conidia called sporidia arise. The sporidia
are formed in succession one after another and the process con-

PRINCIPAL GROUPS OF PLANTS.

67

tinues for some time. On germination they bud like yeast, form-
ing new conidia, or when nutrition is not abundant they may
form a mycelium, which is usually the case when they germinate
on a host plant.

Corn Smut. — One of the Smut Fungi, namely, Ustilago
Maydis, which develops on Indian corn (Fig. 39), is used in medi-

FIG. 40. Spores of various Smuts. I, Ustilago longissima growing on the reed meadow-
grass (Panicularia americana); 2, Ustilago Maydis from Indian corn (Zea Mays); 3, Ustilago
Oxalidis on the yellow wood-sorrel (Oxalis stricta) ; 4, Ustilago utriculosa on the Pennsyl-
vania persicaria (Polygonum pennsylvanicum).

FlG. 4oa. Germination of spores. 5, Ustilago utriculosa, in water, showing promy-
celium and sporidia; 6, Doassansia opaca from the broad-leaved arrow-head (Sagittaria
lalifolia) in water, showing promycelium, sporidia, and secondary sporidia which are falling
off; 7, Ustilago Avenue from oat (Avena saliva) in horse dung, showing promycelium, and
lateral "infection threads" or hyphas; 8, germination of a sporidium of Ustilago Sorghi into
an infection thread; 9, small portion of a group of sporidia developed from promycelium
of Tolyposporium eriocauli in potato agar; 10, cross-section of epicotyl of broom-corn in-
fected by Ustilago Sorghi showing mycelium ramifying through parenchyma cells of the
cortex. — After Clinton.

cine. It forms rather large gall-like masses on all parts of the
plant, including the root, stem and leaves, and both staminate and
pistillate flowers. The spores (Fig. 40) are at first a dark olive-
green, but on maturity are dark brown. They are sub-spherical,
have prominent spines, and vary from 8 to 15 microns in diameter.
They do not germinate at once, but on keeping them for six

68

A TEXT-BOOK OF BOTANY.

months to a year they germinate readily on a culture medium
of potato, and retain their power of germination for years

Rust Fungi. — The Rust Fungi are parasitic on higher plants

FIG. 41. Wheat rust (Pucdnia graminis). A, teleutospore or winter spore germinating
and giving rise to a promycelium (p) and sporidia (s); B, a few leaves of barberry attacked
by sporidia which give rise to the aecidia; C, transverse section through barberry leaf show-
ing three cup-like receptacles (aecidia) on the lower surface of the leaf containing per-
pendicular rows of conidia (secidiospores) ; D, germinating aecidiospore on wheat; E,
wheat plant attacked by aecidiospores as shown by the elongated blotches on the leaves;
F, cross section of leaf of wheat showing on the upper surface the rust spores which are
breaking through the epidermal layer (r); G, summer spores (uredospores) ; H, teleutospores
or winter spores formed on wheat leaf. — After Dodel-Port.

and produce a thread-like branching, cellular mycelium, which
develops in the tissues of the host. They differ especially from the
other Fungi in producing resting spores known as TELEUTOSPORES..

PRINCIPAL GROUPS OF PLANTS. 69

These spores consist of one or more cells surrounded by a thick
black wall, and they produce the "black rust" seen on foliage
at the end of the season.

Wheat Rust. — The most important member of the Rust Fungi
is Puccinia, of which there are a large number of species that are
destructive to economic plants, as wheat, plum, cherry, red cur-
rant, etc. The one whose life history has been best studied is the
wheat rust (Puccinia graminis), which requires two different
plants to complete its life history, namely, wheat and barberry.
The Teleutospores, or "winter spores" (Fig. 41, //), as they
are called, because of their carrying the life of the plant over the
winter season, consist of two cells. These spores exist on the
leaves and stems of wheat over winter, and in the spring they ger-
minate (Fig. 41, A). From each cell a mycelium (promycelium
or basidium) consisting of two to four cells arises (Fig. 41, A, />),
and from the tip of each branch of the promycelium a spore
known as a sporidium develops (Fig. 41, A, s). The Sporidia
are scattered by the wind, and when they fall on the barberry
leaves (Fig. 41, B) they germinate, producing a dense mass or
mycelium which penetrates into the tissues of the host.

Sooner or later, just within the under surface of the leaf,
there is formed a more or less spherical, dense mass, which grows
outward, breaking through the surface, forming a cup-like re-
ceptacle known as an aecidium (Fig. 41, C). The ^Ecidia, or
cluster cups, are orange or yellow and are filled with perpendicular
rows or chains of spores which arise from the basidium-like
mycelium below. The spores, which have received the name
JEcidiospores, are somewhat spherical or polyhedral, and contain
a reddish-yellow oil. They are scattered by the wind and, falling
upon the wheat plant (Fig. 41, £), germinate immediately, form-
ing a dense mycelium. At first it produces what is known as a
" Summer spore," or Uredospore (Fig. 41, G), giving rise to the
reddish-brown spots and stripes on the leaves and stalks of the
wheat plant. The Uredospores are i -celled, and are carried by
the wind to other wheat plants, thus rapidly spreading the disease.

The Uredospores arise in much the same way as the Teleuto-
spores (Fig. 41, //), which form brown patches later in the sea-
son, and which have been already considered. The Teleutospores

70 A TEXT-BOOK OF BOTANY.

last over winter on the old wheat plant, and in the spring begin
again the life-cycle of the rust. The plant which results from
the germination of a teleutospore gives rise to sporidia, which
are carried to the barberry leaves where secidiospores are pro-
duced. The latter are then carried to growing wheat, forming
first uredospores and later teleutospores. It should be remembered
that these are all asexual spores. In regions where there are no
barberry plants to act as host the aecidiospore stage is omitted.

THE FUNGI IMPERFECTI. — The miscellaneous fungi included in
this group are of importance because of the great damage which
they cause to agricultural crops. The potato scab is an especially
destructive pest in New England and in Canada. The scab not only
develops on the growing tubers in the soil, but can be spread from
a few affected potatoes to a whole bin of clean ones if they come
in contact with them. Prevention of this disease usually consists
in disinfecting the tubers which are used for seed so as not to
carry the minute organisms into the soil.

A disease affecting the leaves of the potato and thereby destroy-
ing the crop is due to a fungus whose spores, settling on the leaves,
germinate and penetrate to the interior through the stomata,
finally weakening or killing the plant.

Some of the other important forms produce a pink mold on
apples, scabs on peaches and other fruits, mold on onions and
other garden crops. The blight of ginseng and the blight of
cotton, the dry rot of various vegetables and the blotches on many
of our common fruits can be traced to the development of these
fungi. The study of these forms is a very difficult one, and re-
searches are constantly being carried on at the government experi-
ment stations, as well as by individual workers.

For a description of these forms, as well as many other
harmful fungi, consult " Fungous Diseases of Plants," by Duggar.

DETECTION OF FUNGUS IN HOST. — Unless special means are
employed, it is ofttimes rather difficult to trace the mycelial of the
fungus in among the cells of the host plant. Vaughan (Annals
of the Missouri Botanical Garden, 1914, p. 241) has used the stain
known as " Pianeze Illb " in differentiation of the fungus from
the plant substratum. The host tissue stains green and the my-
celium a deep pink. This stain, devised by Dr. Pianeze for the

PRINCIPAL GROUPS OF PLANTS. 71

study of cancer tissue, is made up as follows : Malachite green,
0.50 Gm. ; acid fuchsin, o.io Gm. ; " Martius gelb," o.oi Gm. ;
water distilled, 150.00 c.c. ; alcohol (95 per cent.), 50.00 c.c. For
use with plant tissues the procedure is as follows : Wash in water
or alcohol, stain in the undiluted mixture 15 to 45 minutes, remove
excess stain in water, and decolorize in 95 per cent, alcohol to
which a few drops of hydrochloric acid have been added. For per-
manent mounts, clear with a carbol-turpentine mixture, remove
clearing solution, and mount in balsam.

This stain is also valuable for staining spores which have been
allowed to germinate on the surfaces of leaves. In such cases
the killing and tissue-clearing mixture proposed by Duggar is
recommended, viz., consisting of equal parts of glacial acetic
acid and alcohol. In the study of the rusts, the best results are
obtained by the use of Durand's combination of Delafield's haema-
toxylin and eosin (Phytopathology, 1911, p. 129).

LICHENS.

General Characters. — The Lichens are a peculiar group of
plants in that an individual lichen consists of both an alga called
a GONIDIUM and a fungus. These are so intimately associated that
they appear to be mutually beneficial, and such a relation is known
as SYMBIOSIS (Fig. 42). The Algae which may be thus associated
in the Lichens are those members of the Blue and Green Algae
which grow in damp places, as Pleurococcus, Nostoc, Lyngbya,
etc. (Fig. 42). The Fungi which occur in this relation belong
both to the Ascomycetes and Basidiomycetes, and it is on the
characters of the fruit bodies of these particular Fungi that the
main divisions of Lichens are based. The Fungi, however, are
not known to exist independently of the Algae with which they
are associated ; that is, the mycelia of the fungi will not live for
any length of time unless they come in contact with suitable
algae. In its development the fungus forms a mycelium which
encloses the alga, the growth of which latter is not hindered. The
two organisms then continue to grow simultaneously, forming
lichen patches. A section of a lichen shows a differentiation into
several parts (Fig. 43) : a more or less compact row of cells on
both surfaces forming two epidermal layers ; and an inner portion

72 A TEXT-BOOK OF BOTANY.

made up of the hyphal tissue of the fungus in which the alga is em-
bedded either in a single layer or throughout the mycelium. The
mode of growth and branching is influenced largely by the fungus,
although in some cases the alga may exert the most influence. In
some cases the lichen consists of a thallus which is irregular in
outline, growth taking place at no definite point, and in other
cases branches which are more or less regular are formed, growth
taking place at the apex.

FIG. 42. Lichens showing manner of union of algae or gonidia (g) and hyphas (h) of
Fungi. A, Protococcus, showing the manner in which hyphae penetrate the cell and in-
fluence cell division; B, Scytonema, an alga surrounded by richly branching hyphas; C, chain
of Nostoc showing hypha of fungus penetrating a large cell known as a heterocyst; D, fungal
hyphae have penetrated the cells of Glceocapsa, a blue-green, unicellular alga; E, Chlorococcum,
a reddish or yellowish alga found in Cladonia furcata, the cells of which are surrounded by
the short hyphae of the fungus. — A, after Hedlund; B-E, after Bornet.

The walls of the hyphae of the fungus comprising Lichens con-
sist at first of pure cellulose. In older material the walls undergo
more or less modification, being changed in part to starch, mucilage,
or fixed oil. There may be also infiltrated among the layers of
the wall calcium oxalate, the latter constituent being especially
characteristic of the crustaceous Lichens. The most interesting
constituents of Lichens are the coloring principles, which are
mostly of an acid character and are termed Lichen-acids. They

PRINCIPAL GROUPS OF PLANTS. 73

give very striking reactions with solutions of the alkalies and solu-
tions containing chlorine. The reaction with iodine solutions is
also employed for diagnostic purposes ; some of the Lichens give
a blue reaction, while others behave like amylo-dextrin.

Groups of Lichens. — According to the manner of growth
and the manner of attachment to the substratum, three principal
groups of Lichens may be distinguished : namely, ( i ) Crus-
taceous Lichens, where the thallus adheres closely to the stones
and barks of trees and practically can not be removed without
injury; (2) Foliose Lichens, or those which are more or less
flattened, somewhat leaf-like and attached at different points; (3)
Fruticose Lichens, or those which are attached at a particular
part of the thallus, and form diffusely branching clumps. To this
latter group belong Cetraria islandica or Iceland moss (Fig. 43),
which is used in medicine, Usnea barbata and the red-fruiting
Cladonias which are so common.

Reproduction in the Lichens takes place in several ways. In
all of them there is a vegetative mode by means of what are
known as SOREDIA. These are small spherical bodies consisting of
a group of algal cells, which are surrounded by a mass of hyphae,
and which when cut off from the main body are able to grow.
Lichens also produce spores of a number of kinds. In the largest
group, the one to which Cetraria islandica (Fig. 43) belongs, the
spores are found in special spherical receptacles, known as PYC-
NIDIA, which are formed on the teeth of the margin of the thallus.
The spores arise from the ends of hyphse at the base of the pyc-
nidia and are in the nature of conidiospores. To these spores
the name PYCNOCONIDIA has been applied. Cetraria also pro-
duces, like many other Lichens, disk-like or cup-shaped bodies at
various places on the surface of the thallus, which are known as
APOTHECIA and which may be regarded as exposed or open asco-
carps. The inner surface of the apothecia is lined with a number
of asci as well as sterile cells, the former giving rise to ascospores.

Economic Uses of Lichens. — A number of the Lichens are
used in medicine, as several species of Cetraria, Pertusaria corn-
munis, Physica parietina, Sticta pulmonacea, Evernia furfuracea.
Some of those used in medicine are also used as foods on account

74

A TEXT-BOOK OF BOTANY.

of the gelatinous carbohydrate lichenin which they contain. Be-
sides those given, the following may be mentioned : Cladonia
rangiferina (reindeer moss), Lecanora esculenta (supposed to be
the manna of the Israelites). The Lichens are, however, chiefly
of interest because of the coloring principles which they contain.

FIG. 43. Iceland Moss (Cetraria islandica). A-F, various forms of thalli showing
apothecia (a); I, cross-section of an apothecium showing the hymenium (h), the hypothe-
cium (p), the algal layer (e), the medullary layer (m), and lower or ventral surface (1); K,
an ascus with eight ascospores and two paraphyses from the hymenium (h).

Roccella tinctoria, Lecanora tartarea, and other species of Leca-
nora, yield upon fermentation the dyes orcein and LITMUS, the
latter of which finds such general use as an indicator in volu-
metric analysis. Cudbear, a purplish-red powder, is prepared by
treating the same lichens with ammonia water ; while in the prep-

PRINCIPAL GROUPS OF PLANTS. 75

aration of orchil, a purplish-red pasty mass, sulphuric acid and
salt are subsequently added. A number of species contain a yel-
low coloring principle, as Zeora sulphur ea, Zeora sordida, Lecidca
geographica and Opcgrapha epigcca.

ARCHEGONIATES.

The two main features which distinguish the Archegoniates
from the Thallophytes are the structure of the sexual organs and
the distinct manner in which the peculiar phases known as alter-
nation of generations are shown. The antheridium or male sexual
organ is a well differentiated multicellular body which is either
sunk in the adjacent tissues of the plant or is provided with a
stalk. Within it are organized the sperms or spermatozoids, which
are ciliate and swim freely in water. Corresponding to the oogo-
nium of the Thallophytes is the ARCHEGONIUM or female sexual
organ which gives name to the group. The archegonium is a
flask-shaped cellular body consisting of a basal portion of venter,
which contains a single egg, and a neck through which the sperms
enter (Figs. 49 and 51).

In the life history of this group of plants there are two gen-
erations or phases of development. During one stage the arche-
gonium and antheridium are developed, and this is known as the
sexual generation, and as these organs give rise to gametes or
sexual cells it is also spoken of as the GAMETOPHYTE. By the union
of the sex cells (sperm and egg) an oospore is formed which
germinates at once within the archegonium. That portion of the
plant which develops from the oospore gives rise to asexual
spores, and hence this phase is called the asexual generation.
It is also spoken of as the SPOROPHYTE from the fact that it gives
rise to spores. These spores are in the nature of resting spores
and do not germinate on the plant as does the oospore. They are
distributed and on germination give rise to the gametophyte stage.

In some of the Archegoniates these two phases are combined
in one plant, as in the Bryophytes, whereas in other members of
the group the two phases are represented by two distinct plants ;
that is, the gametophyte and sporophyte become independent of
each other, as in the Ferns.

76

A TEXT-BOOK OF BOTANY.

The following table shows the main divisions and subdivisions
of the Archegoniates :

Bryophytes.. , {Hepatic* (Liverworts).

J f J \ -71 If • / -l yp

[Musci (Mosses).

Archegoniates

Pteridophytes . .

Filicales (Ferns).
Equisetales (Horsetails).
Lycopodiales (Club Mosses)

BRYOPHYTES

The structure of the sexual organs in the Liverworts (Fig. 44)
and Mosses (Fig. 49) is essentially the same, but the vegetative
organs are more or. less dissimilar. In the Liverworts the plant

FIG. 44. A common moss (Funaria). A, germinating spores: v, vacuole; w, root-
hair; s, exospore. B, protonema about three weeks after germination: h, procumbent
primary shoot; b, ascending branch of limited growth; K, bud or rudiment of a leaf -bearing
axis with root-hair (w). — After Sachs.

body or thallus lies more or less close to the substratum or rises
somewhat obliquely, whereas in the Mosses the part we designate
as the plant is in all cases an upright leafy branch. The moss
plant is said to have a radial structure from the fact that the
leaves radiate from a central axis, while in the Liverworts the
thallus is dorsiventral ; that is, as a result of its habits of growth,
it is characterized by having a distinct upper and lower surface.

PRINCIPAL GROUPS OF PLANTS.

77

The Life History of this group of plants may probably be
best illustrated by following that of a moss plant. Beginning
with the germination of an asexual spore which is microscopic in
size and which germinates on damp earth, there is produced an

FIG. 45. A common moss (Polytrichum gracile). A, showing leafy branches (gameto-
phores) two of which bear sporogonia, a detached sporogonium (sporophyte) with sporan-
gium from which the calyptra (ca) has been detached. B, longitudinal section through a
nearly ripe sporangium showing columella (o), the elongated area of sporogenous tissue
(archesporium) on either side, annulus (n), peristome (p), lid or operculum (u); C, trans-
verse section of sporangium showing columella in center and dark layer of sporogenous
tissue (archesporium); D, ripe sporangium (capsule) showing the escape of spores after
detachment of lid; E, ripe spore containing large oil globules; F, ruptured spore showing
separated protoplasm and oil globules; G. two germinating spores 14 days after being sown,
showing beginning of protonema in which are a number of ellipsoidal chloroplasts. — After
Dodel-Port.

78 A TEXT-BOOK OF BOTANY.

alga-like body consisting of branching septate filaments, which is
known as the PROTONEMA, or prothallus (Fig. 44). The Proto-
nema lies close to the surface of the ground and is more or less
inconspicuous except for the green color. From the lower por-
tion thread-like processes, or rhizoids consisting of a row of cells,
are developed, which penetrate the ground. Sooner or later lateral
buds arise from some of the lower cells. Growth continues from
an apical cell which divides and gives rise to cells that differentiate
into stem and leaves, forming an upright branch, which consti-
tutes the structure commonly regarded as the " moss plant " (Fig.
45, A). The leaf-bearing axis varies considerably in size; in
some cases it is but a millimeter high, whereas in some species, as
Polytrichum (Fig. 45), it may be several hundred millimeters in
height. At the tip of the branch the antheridium (Fig. 49, A)
and archegonium (Fig. 49, B) are formed. These organs are
developed in among the leaves and certain hairy processes, known
as paraphyses ( Fig. 49, p) . They may both occur at the end of one
branch (Fig. 49, C) or they may occur on separate branches
(Fig. 49, D), when the plants are said to be monoecious, whereas
when these organs occur on separate plants (Fig. 49, At B) the
plants are called dioecious. In the case of dioecious plants the
plant bearing the antheridium is frequently smaller and less com-
plex than the one producing the archegonium. As already stated,
the archegonium produces the egg-cell or female gamete (egg)
and the antheridium, the sperm cell or male gamete (sperm).

The sperms in the Bryophytes are more or less filiform and
are provided with a pair of cilia at one end. The antheridia,
towing to the peculiar mucilaginous character of the cells, only
open when there is an abundance of moisture, when the sperms
are discharged and move about in the water, some being carried
to the archegonium, which likewise opens only in the presence of
moisture. With the transferral of the sperms to the archegonium
and the union of one of these with the egg which remains sta-
tionary, the work of the garnet ophyte may be said to be com-
pleted. The act of union of the egg and sperm is known as
FERTILIZATION, and when this is effected the next phase of the
life history begins.

The egg after fertilization divides and re-divides within the

PRINCIPAL GROUPS OF PLANTS. 79

archegonium, which becomes somewhat extended until finally it
is ruptured. The dividing cells differentiate into a stalk and a
spore case or sporangium which is borne at the summit, the whole
structure being known as the SPOROGONIUM (Fig. 45). The
base of the stalk is embedded in the apex of the moss plant,
and is known as the foot, it being in the nature of a hausto-
rium or nourishing organ. As the sporogonium develops and
rises upward it carries with it the ruptured archegonium which
forms a kind of covering over the top, called the calyptra
(Fig. 45, ca). At first the sporangium is more or less uniform,
but eventually differentiates into two kinds of tissues, the one
being sterile and the other fertile (producing spores), which latter
is known as the ARCHESPORIUM (Fig. 45, B, C). The fertile tissue
in both the Liverworts and Mosses is variously disposed ; some-
times it forms a single area and is dome shaped, spherical, or
in the form of a half sphere. In other cases it is separated into
two areas by sterile tissue. The sterile tissue which extends up
into the dome-shaped archesporium, or which in other cases
separates the fertile tissue into two parts, is known as the
columella (Fig. 45, B, C). The sporangium in the mosses is
capsule-like and the spores are distributed in three ways : ( i )
In some cases the capsule does not open, but when it decays the
spores are liberated. (2) In other cases the capsule dehisces
longitudinally in dry weather, and thus the spores are freed.
(3) There is a third method in which the capsule is provided
with a lid or operculum which comes off and permits the spores
to escape, this being the most common method for the escape
of the spores (Fig. 45, D). In the latter instance the mouth
of the capsule is usually marked by one or two series of cells,
constituting the PERISTOME, which are teeth-like and characteristic
for some of the groups of mosses. These teeth bend inward or
outward, according to the degree of moisture, and assist in regu-
lating the dispersal of the spores. In the sphagnum mosses there
is no peristome, but, owing to unequal tension of the lid and capsule
on drying, the lid is thrown off, and the spores are sometimes
discharged with considerable force and sent to quite a distance
(as much as 10 centimeters), in this way insuring their dispersal.
The spores (Fig. 45, E) vary in diameter from 10 to 20

8o A TEXT-BOOK OF BOTANY.

microns, being sometimes larger. They occur in groups of four
in a mother-cell, and the spore-group is known as a tetrad, which
is characteristic for the Bryophytes and the higher groups of
plants. The spores therefore vary in shape from spherical tetra-
hedrons to more or less spherical bodies, depending upon the
degree of separation. The contents are rich in protoplasm and
oil (Fig. 45, F). The wall consists of two layers, the outer of
which is either yellowish or brown and is usually finely sculptured.
At the time of germination the outer wall is thrown off, and the
protonema develops (Fig. 45, G). The spores may germinate
almost immediately, or only after a considerable period. These
spores are asexual and each one is capable of giving rise to a
new plant. With the formation and dispersal of the spores the
work of this generation terminates, and this phase is called the
sporophyte or asexual generation, from the fact that it produces
spores.

Having thus followed the stages of development in the life
history of a moss, we see that it is composed of the following
parts: (i) The alga-like protonema; (2) the leafy branch which
gives rise to an oospore (sexual spore), and (3) the sporogonium
which produces asexual spores. The leafy branch is sometimes
spoken of as the gametophore (gamete-bearer), and it and the
protonema together constitute the gametophyte or sexual gen-
eration, while the sporogonium represents the sporophyte or
asexual generation.

The protonema sooner or later dies off in most plants, but in
other cases it persists, forming a conspicuous portion of the
gametophyte.

HEPATIC^.

General Structure. — The Hepaticse or Liverworts (Fig. 46)
are usually found in moist situations. The protonema formed on
germination of a spore is filiform, and the plant body which
develops from it consists of a flat, dichotomously-branching
thallus, or it may in some of the higher forms differentiate into
a leafy branch, as in the leafy liverworts. The thallus, owing to
its position, has an upper and an under surface which are some-
what different, as in Marchantia (Fig. 46), hence it is said to be

PRINCIPAL GROUPS OF PLANTS.

81

DORSIVENTRAL. From the lower colorless surface unicellular
rhizoids arise (Fig. 47, h). The upper surface consists of several
layers of cells containing chlorophyll which give the green color
to the plant.

Vegetative propagation may ensue by the lower portion of
a branch dying and the upper portion continuing as an inde-
pendent plant. Or special shoots, known as GEMMAE,, may arise

FIG. 46. Dichotomously branching thallus of the common liverwort (Marchantia
Polymorpha) showing near some of the margins the cup-like depressions in which gemmae
are borne (c), and several archegoniophores (a).

either on the margin of the thallus or in peculiar cupules, which,
when detached by rain or other means, are capable of growing
and producing a new plant.

In addition the thallus body produces both antheridia and arch-
egonia (Fig. 46) which may arise on special stalks above the sur-
face. After fertilization of the egg-cell, which completes the work
of the sexual generation of gametophyte, the sporophyte develops,
6

82

A TEXT-BOOK OF BOTANY.

producing a sporogonium consisting of a short stalk which is
embedded in the tissues of the gametophyte, and a capsule (spor-
angium). The latter at maturity dehisces or splits and sets free
the spores, which are assisted in their ejection by spirally banded
cells called " elaters " (Fig. 48, C-F). The spores on germination
give rise to a protonema which then develops a thallus bearing the
sexual organs. As in the mosses, the sporogonium represents the
asexual generation known as the sporophyte.

Liverwort Groups. — There are three important groups of

chl

FIG. 47. Transverse section through the thallus of Marchantia Polymorpha. A,
middle portion with scales (b) and rhizoids (h) on the under side; B, margin of the thallus
more highly magnified, showing colorless retieulately thickened parenchyma (p), epidermis
of the upper side (o), cells containing chlorophyll (chl), air pore (sp), lower epidermis (u).
—After Goebel.

Liverworts: (i) The MARCHANTIA Group (Fig. 46), in which
the thallus is differentiated into several layers and so somewhat
thickened. Another character is the diversity in form of the
sexual organs, which range from those which are quite simple to
those which are highly differentiated. In Riccia the sexual organs
are embedded on the dorsal (upper) side of the thallus, while in
Marchantia they are borne upon special shoots, one, which has a
disk at the apex that bears the antheridia, known as the antheridio-
phore, and another whose summit consists of a number of radiate

PRINCIPAL GROUPS OF PLANTS. 83

divisions and bears the archegonia (Fig. 46) on the lower sur-
face, known as the archegoniophore ; these being borne on separate
plants. In Riccia, the simplest of the Liverworts, the sporangium
is enclosed by the thallus and the spores are not liberated until the
decay of the plant.

(2) The JUNGERMANIA Group, known as " Leafy Liver-
worts " or " scale mosses," includes those forms which are more

FIG. 48. Anthoceros gracilis, one of the liverworts. A, thallus with 4 sporogonia;
B, a ripe elongated sporogonium, dehiscing longitudinally and showing two valves between
which is the slender columella; C, D, E, F, various forms of elaters; G, spores. — After
Schiffner.

or less moss-like and develop stems and small leaves. The sporo-
gonium has a long stalk and the capsule is 4-valved, i.e., separates
into four longitudinal sections at maturity.

(3) In the ANTHOCEROS Group (Fig. 48) the gametophyte
is thallus-like and very simple in structure, the sexual organs being
embedded in the thallus. The sporogonium is characterized by a
bulbous foot and an elongated, 2-valved capsule. Like the thallus,

84 A TEXT-BOOK OF BOTANY.

it develops chlorophyll and possesses stomata resembling those
found in certain groups of mosses and higher plants.

MUSCI.

in the Mosses the archegonia always form the end of the
axis of a shoot, whether this be a main one or a lateral one. As
has already been stated (p. 78), the sexual organs are surrounded
by leaves or leaf-like structures, known as perichaetia or peri-
chsetal leaves, and by hair-like structures or paraphyses, both of
which are considered to act as protective organs. Sometimes
the groups of sexual organs together with the protective organs are
spoken of as the " moss flower." As already stated, the Mosses
are both monoecious (Fig. 49, C, D) and dioecious (Fig. 49, A,
B), hence a moss flower may contain only one of the sexual organs
or it may contain both. Mosses are also characterized by an
abundant vegetative propagation. New branches are developed
from the old. " Almost every living cell of a moss can grow out
into protonema, and many produce gemmae of the most different
kinds." Entire shoots provided with reserve material are cut
off and form new plants. In this way moss carpets are frequently
formed in the woods, or masses in bogs.

Moss Groups. — There are two general classes o>f mosses : ( i )
SPHAGNUM forms are those which produce leaves without nerves,
and in which the sporogonium does not possess a long stalk or
seta. What appears to be the stalk is the prolongation of the
gametophyte stem which is known as the pseudodiurn or " false
stalk." These forms are characteristic of wet places. Some of
the group, as Sphagnum proper, form " sphagnum bogs." New
plants develop on top of the old, which latter gradually die and
finally pass into sphagnum peat, which forms thick masses and
finds use as a fuel. (2) The TRUE MOSSES are especially distin-
guished by the differentiated character of the sporogonium, which
not only produces a stalk but also the peristome (Fig. 45, />),
which when present is of great importance in distinguishing the
different species.

Economic Uses of Bryophytes. — The investigations on the
chemistry of the Liverworts and Mosses have not been very
numerous. The constituents which have been found are in the

PRINCIPAL GROUPS OF PLANTS. 85

nature of tannin, resins, ethereal oils, glucosides, alkaloids, color-
ing compounds, and organic acids like citric, oxalic, tartaric, and
aconitic. In the mosses starch and silicon salts are found in
addition. Several species of Marchantia and Jungermannia are

FIG. 49. Longitudinal sections through tips of leafy branches of mosses. A, show-
ing antheridia (a, b) in different stages of development and paraphyses or cell-threads
(c), the apical cell of which is spherical and contains chlorophyll, and leaves (d, e); B, show-
ing archegonia (a) and leaves (b) ; C, section of Bryum showing both archegonia, and an-
theridia, paraphyses, and leaves; D, section of Phascum showing archegonia (ar), antheridia
(an), thread-like paraphyses (p), and leaves (b). — A, and B, after Sachs; C, after Limpricht;
D, after Hofmeister.

used in medicine. Of the mosses the following have been found
to have medicinal properties: Sphagnum cuspidatum, Grimmia
pulvinata, Funaria hygfometrica, Fontinalis antipyretica, and sev-
eral species of Polytrichum and Hypnum.

86 A TEXT-BOOK OF BOTANY.

PTERIDOPHYTES.

The Pteridophytes were formerly known as the VASCULAR
CRYPTOGAMS. Like the Bryophytes, these plants show a distinct
alternation of generations ; i.e., the gametophyte or sexual genera-
tion alternates with the sporophyte or asexual generation. Their
relation is, however, somewhat changed. In the Bryophytes the
gametophyte is the most conspicuous and is looked upon as con-
stituting the plant proper, whereas in the Pteridophytes the
gametophyte is rather insignificant in size, while the sporophyte
constitutes the generation or phase which is ordinarily regarded
as the plant. In the higher members of the Pteridophytes the
sporophyte is entirely detached from the gametophyte and is able
to lead an independent existence. This group also shows a dis-
tinct advance in structure. There is a differentiation into root,
stem, and leaves, and the development of a system of conducting
tissue known as the VASCULAR SYSTEM.

The Pteridophytes include three principal groups, namely, ( I )
Filicales or Ferns, (2) Equisetales or Scouring Rushes, and (3)
Lycopodiales or Club Mosses, which differ considerably in general
appearance and general morphological characters.

With the exception of the sperms in the Club Mosses, which
are biciliate and somewhat resemble those in the Bryophytes, the
sperms in the Pteridophytes are spirally coiled and multiciliate,
and according to the number of cilia of the sperms some writers
divide the Pteridophytes into two classes, namely, biciliate and
pluriciliate (Figs. 51, C; 62, F).

Some of the Pteridophytes, as Selaginella (Fig. 60), are dis-
tinguished by the fact that they produce two kinds of asexual
spores, which are known respectively as MICROSPORES (Fig. 60,
F) and MEGASPORES (Fig. 60, E). The two kinds of spores are
formed in separate sporangia, which organs may occur on the
same plant or on different plants. The sporangia have the cor-
responding names, microsporangia (Fig. 60, B, i) and megaspor-
angia (Fig. 60, B,g). This differentiation in sporangia and spores
also leads to a differentiation in the resulting gametophytes, the
microspores giving rise to gametophytes which produce antheridia,
and hence called male gametophytes; and the megaspores to

PRINCIPAL GROUPS OF PLANTS. 87

gametophytes which give rise to archegonia, and hence called
female gametophytes. When a plant produces both microspores
and megaspores it is said to be HETEROSPOROUS, as in Selaginella
(Figs. 60, 62, and -63) ; while one that produces but one kind of
sporangium and one kind of asexual spores is said to be ISOSPOROUS.
In this connection attention should be called to the fact that the
spores from a single sporangium of an isosporous plant may give
rise to male and female gametophytes, which shows that a certain
degree of differentiation in the spores has already taken place.
The causes leading to the differentiation of the spores seem to be

B

FlG. 50. Male fern [Dryopteris (Aspidium or Nephrodiuni) Filix-mas], A, prothallus
of gametophyte as seen from the under (ventral) side showing archegonia (ar), antheridia
(an), and rhizoids (rh) ; B, prothallus showing young plant (sporophyte) which has devel-
oped from an oospore and is still connected with the gametophyte, roots (w), and the first
leaf (b).— After Schenck.

connected with nutrition, those nuclei which are in more favorable
positions giving rise to larger and better nourished spores which
eventually lead to the formation of the megaspores, and those
which are less favorably placed leading to the microspores.

The subject of heterospory is one of great interest, and when
it is pointed out that all of the higher plants are heterosporous
the subject has even more interest.

FILICALES.

General Characters. — On germination the asexual spore in
the Filicales or Ferns gives rise to a thallus-like body known as

88

A TEXT-BOOK OF BOTANY.

the prothallus which is frequently dorsiventral and in a number
of cases somewhat heart-shaped, but varies considerably in out-
line, being sometimes more or less tuberous. The prothallus is
frequently but a few millimeters in diameter, and the cells usually
contain chloroplasts. On the under or ventral surface rhizoids
are usually present (Fig. 50, rh). The sexual organs usually
arise on the lower surface (Fig. 50), but they may develop on the
upper or dorsal surface or even laterally. A single prothallus
gives rise to both kinds of organs, unless stunted in its growth,
when it produces antheridia only.

FIG. 51. A, B, development of archegonia of a fern (Pteris) showing the neck (h),
the neck-canal cells (k), and oosphere (e). — After Strasburger.

C, development of antheridium in the Venus-hair fern (Adiantum Capillus-Veneris):
prothallus (p), antheridium (a), sperm (s), sperm mother cell with starch grains (b);
I, immature state of antheridium, II, sperms developed, and III, discharge of sperm mother
cells and escape of coiled and pluriciliate sperms. — After Sachs.

The antheridia either develop upon or are sunk in the tissues
of the prothallus. The archegonia (Fig. 51) are not flask-shaped
as in the Bryophytes. The venter containing the oosphere or egg-
cell (Fig. 51, e) is embedded in the thallus, the structure being
surmounted by a few-celled neck (Fig. 51, h). The inner cells of
the neck are known as canal cells (Fig. 51, k), and these at the
time of ripening of the egg swell and exit through the opening of
the archegonium, through which then the sperms enter, one of
which unites with the egg, thus effecting fertilization. The fer-
tilized egg or oospore takes on a cellulose membrane.

PRINCIPAL GROUPS OF PLANTS.

89

The oospore which is held in the venter of the archegonium is
not a resting spore, but germinates immediately and early differen-
tiates into the several organs (Fig. 52) . These arise independently
and include a stem-bud (Fig. 52, /) ; a first leaf or cotyledon
(Fig. 52, b), so called because it does not arise out of the stem as
the later leaves do; a first or primary root (Fig. 52, w) ; and
a foot or haustorial organ (Fig. 52, /) whereby it obtains nutri-
ment from the prothallus (Fig. 52, pr) . This latter organ is, how-
ever, only a temporary provision, for as soon as the root grows
out and penetrates the soil, it dies off and the sporophyte thus
becomes independent. The stems are frequently more or less con-

A

FIG. 52. The brake fern (Pteris). A, differentiation of cells in germinating oospores;
B, later stage showing development of embryo: pr, prothallus; f, foot embedded in the
archegonium (aw); w, root; s, young stem; b, young leaf. — A, after Kienitz Gerloff; B,
after Hofmeister.

densed and lie prostrate in the soil, developing roots from the
under surface and leaves from the sides and upper surfaces. The
leaves which constitute the conspicuous part of the ordinary ferns
consist of a stalk and lamina or blade on which are borne the spor-
angia (Figs. 53 to 55). The sporangia usually occur on the
under surface of the leaf in groups or clusters known as SORI
(Fig. 53, A). The sori are of characteristic shape and in certain
species are covered by a plate called the INDUSIUM (Fig. 53, B)
which rises from the epidermis. In some species the entire leaf
becomes a spore-bearing organ, and is then known as a SPORO-
PHYLL (Figs. 54, 55), to distinguish it from the foliage leaves.
The sporangia develop a row of cells around the margin consti-

A TEXT-BOOK OF BOTANY.

tuting what is known as the ANNULUS (Fig. 53, «). The form of
the annulus determines the manner of dehiscence of the sporangia,
which occurs on drying. The spores are ejected with consider-

FIG. 53. Male fern [Dryopteris (Aspidium or Nephr odium) Filix-mas}. A, portion
of leaflet showing a number of more or less reniform sori near the mid-vein; B, transverse
section through a ripe sori showing clusters of stalked sporangia, which are covered by
the indusium (i), an outgrowth of the leaflet; C, a closed but ripe sporangium showing the
annulus or ring (n), and the irregular-shaped spores within; D, showing the manner of
bpening of the mature sporangium and the dispersal of the spores; E, two spores much
magnified. — After Dodel-Port.

able force (Fig. 53, D). They (Fig. 53, E; Fig. 57) are either
bilateral or tetrahedral and require a short period to elapse before
they germinate. They retain their vitality for a long1 time, except
those which are green, i.e., contain chlorophyll. The spores are

PRINCIPAL GROUPS OF PLANTS. 91

greenish or yellowish in color, variously sculptured, and vary
from 0.025 mm. to 0.158 mm. in diameter.

Fern Groups. — There are a number of distinct groups of

FIG. 54. Several Osmundas. i, the royal fern (0. regalis) showing fertile tip of
branch and sterile bipinnate leaflets below; 2, Clayton's fern (O. Claytoniana) showing
three pairs of fertile leaflets in the middle and a number of sterile leaflets above and below;
3, cinnamon fern (O. cinnamomea) showing a fertile leaf (sporophyll) to the left and a sterile
leaf (foliage leaf) to the right,

ferns which vary considerably in appearance. ( I ) In the Tropics
as well as in greenhouses TREE FERNS, characterized by an over-
ground stem, occur. The leaves arise at the summit of the stem
or trunk and form a crown.

92 A TEXT-BOOK OF BOTANY.

(2) The TRUE FERNS include by far the largest number of
species which inhabit temperate regions. These vary consider-
ably in size, ranging from quite diminutive plants 5 to 12 cm. high,
as the slender Cliff Brake (Pellcea atropurpurea and the variety

FlG. 55. Different types of Perns and fern allies. I, fertile and sterile leaves of slender
cliff brake (Pellaea Stelleri); 2, ebony spleen-wort (Asplenium platyneuron) ; 3, rhizome
with two leaves of the common polypody (Polypodium vulgare) ; 4, maiden-hair spleen-
wort (Asplenium trichomanes) ; 5, ternate grape-fern (Botrychium ternatum), showing the
tripinnate sterile leaf on the left and the upright sporophyll on the right; 6, walking fern
(Camptosorus rhizophyllus) showing a new plant developing from the tip of one of the leaves;
7, fertile and young sterile leaves of ostrich fern (Onoclea Struthiopteris).

PRINCIPAL GROUPS OF PLANTS.

93

cristata) and maiden hair spleenwort (Asplenium T rich o mane s) ,
to plants several feet high, as in the several species of Osmunda
(Fig. 54), ostrich fern (Fig. 55), etc. This group is chiefly

B

FIG. 56. A, transverse section of stipe of Dryopteris marginalis: E, epidermis; H,
hypodermis of collenchymatous cells; P, parenchyma containing starch; V, fibrovascular
bundle; S, sieve; T, tracheae; N, endodermis surrounding each bundle. B, transverse sec-
tion of stipe of Osmunda Claytoniana: H, hypodermis of lignified sclerenchymatous fibres;
N, endodermis surrounding a large central fibrovascular bundle; Tn, tannin cells.

characterized by the underground or prostrate stems, known as
rhizomes, the part of the plant that is seen above ground being
the leaf.

94

A TEXT-BOOK OF BOTANY.

(3) There is also a group of ferns known as WATER FERNS
which are aquatic in habit ; that is, they live in marshy places or
float on water. As representatives of this group may be men-
tioned Marsila, from whose slender rhizome that is buried in the

FIG. 57. Some fern spores. A, B, C, different views of the bilateral spores of the
common polypody (Poly podium vulgar e), showing outer wall (ep), middle wall (ex), inner
wall (end) and line of dehiscence (dl) ; D, a tetrahedral spore of the royal fern (Osmunda
regalis); E, F, spores of Ceratopteris thalictroides seen in two views. — A-D, after Sadebeck;
E-F, after Kny.

muddy bottom of streams arise the clover-like leaves that
float on the water (Fig. 59) ; and Salvinia (Fig. 58), which is a
small floating plant that develops two kinds of leaves, one which
float on the surface of the water and are more or less oblong, and

FIG. 58. A water fern (Salvinia natans). A, a plant seen from side and showing
floating leaves at top attached to the horizontal stem, root-like finely divided leaves beneath,
and a cluster of globose sporocarps; B, a view from above showing especially the character
of the upper leaves; C, young plant developing from a megaspore (msp). — A and B, after
Bischoff ; C, after Pringsheim.

another which are filiform, branching, root-like, and submerged.
The water ferns are further distinguished by the production of
megaspores and microspores.

(4) The ADDER'S TONGUE FAMILY, to which Ophioglossum

PRINCIPAL GROUPS OF PLANTS. 95

and Botrychium belong, develops a subterranean prothallus which
is destitute of chlorophyll. The prothallus is in some cases tube-

FIG. 59. Marsilea quadrifolia (from Bantam Lake, Conn.), a submersed or emersed
aquatic plant belonging to the Marsileaceae, a family of the Pteridophytes. Of the forty
different species, only two or three are found in the United States. It produces long, slender
rhizomes, which are buried in the muddy bottoms of shallow lakes or streams and from
which arise the leaflets which float on the surface. The leaves are on long, slender petioles
and 4-foliate, the leaflets being mostly triangular-obovate. In Marsilea quadrifolia, a
European form growing in Connecticut and Massachusetts and frequently cultivated, the
leaves are nearly glabrous, while in M. vestita, a form found in shallow ditches in the
Southern States, the leaflets are usually hairy. This character is quite marked in the spor-'
ocarps of the two plants. — After a photograph by Henry Troth.

96 A TEXT-BOOK OF BOTANY.

rous, and the sporophyte produces two kinds of leaves, namely,
foliage leaves, and fertile leaves or those which bear the sporangia.
The sporangia occur on lateral branches of the sporophyll and
open at maturity by means of a horizontal slit.

Ferns Used in Medicine and as Foods. — Many of the ferns
contain tannin, a brownish coloring principle, and in addition
an anthelmintic principle. They may also contain ethereal oils,
starch, coumarin, aconitic acid, and other principles. A large
number have been used in medicine, of which the following may
be mentioned: Dryopteris (Aspidium or Nephrodium) maryinalis
and D. Filix-mas, yielding the official Aspidium. A number of
other species of Aspidium, as well as species of Adiantum, As-
plenium and Polypodium, are also used in various parts of the
world. The rhizomes of some of the ferns contain considerable
starch and are used to some extent as foods, as Pteris esculenta of
China ; Pteridium aquiliana var. lanuginosa of the Canary Islands ;
Aspidium varium and Asplenium bulbosum of Cochin China.
Polypodium vulgare contains a substance related to glycyrrhizin.
Adiantum pe datum and Polypodium Phymatodes are said to con-
tain coumarin, the latter plant being used in perfumery.

EQUISETALES.

The Horsetails, or scouring rushes (Equisetums), are peren-
nial plants containing a large amount of silica in their tissues.
Like in the ferns, the more or less branching, creeping rhizome
persists from year to year, sending out each year new shoots. As
in some of the ferns, it develops two distinct kinds of leaf-shoots, a
fertile and a sterile one, each of which is distinctly jointed. The
scale-like leaves are arranged in circles about the joints or nodes,
the work of photosynthesis being carried on by the green stems.
The fertile branch develops at the apex a group of sporophylls
known as a cone or strobilus. The archesporium, or initial spore-
producing zone, is unilocular. In Equisetum, the only representa-
tive of the group, the spores are spherical and each is furnished
with two spiral bands or elaters which assist in its dispersal. Some
of the Equisetums contain aconitic acid and are used in medi-
cine. Common scouring rush (Equisetum hyemale) is used for

PRINCIPAL GROUPS OF PLANTS. 97

polishing woods, and Equisetum arvense is used for scouring
tinware.

LYCOPODIALES.

The Lycopodiales, or Club Mosses (Fig. 66),- are perennial
moss-like plants, with more or less erect or creeping and branching
stems, on which are borne numerous small simple leaves. The
sporangia arise either at the .base of the upper surface of the leaves
or occur in terminal cones. They have short stalks, are uni-
locular and 2-valved. The asexual spores are of one kind in
Lycopodium and in the form of spherical tetrahedrons, resulting
from the manner in which division has taken place (see Vol. II).
In Selaginella (Fig. 60) two kinds of asexual spores are produced,
that is, both microspores and megaspores, which in turn give rise
to male and female prothalli respectively. The microspore develops
a male gametophyte (Fig. 62) which remains entirely within the
spore, and consists of a few-celled prothallus and a number of
mother cells which produce sperms that eventually escape by the
breaking of the wall.

The megaspore frequently begins to develop the gametophyte
(Fig. 63) while still within the sporangium. The prothallus con-
sists of a number of cells and partly protrudes through the rup-
tured spore wall. On the upper part of the prothallus or nutri-
tive layer a few archegonia are borne. It should be stated that
sometimes the archegonia are developed very early on the pro-
thallus tissue, but usually they are developed after the spores
have escaped from the sporangium. After fertilization of the egg
a multicellular embryo develops which shows the following parts
(Fig. 61) : (i) An elongated cell or row of cells which extends
into the tissues of the prothallus for the purpose of obtaining
nutriment; (2) a root; and (3) a stem bearing at its tip two
leaves, or cotyledons. One of the specially notable characters
of the plants of the Selaginella group is, as we have seen, the
great reduction in size of the gametophyte, which in the case of
the microspore does not enlarge beyond the wall of the spore, and
in the case of the megaspore only partly protrudes beyond its wall.

Isoetes. — This is a genus of aquatic or marsh plants known
7

98

A TEXT-BOOK OF BOTANY.

as quillworts. The plants produce a number of filiform roots
which penetrate the mud, and a compact tuft of rush-like leaves.
The plants are heterosporous, as in Selaginella. The sporangia

FIG. 60. Selaginella helvetica. A, sporophyte consisting of leafy branches giving
rise to microsporangia (i), megasporangia (g), and rhizoids (r); B, longitudinal section of
portion of branch showing a megasporangium (g) with 3 megaspores in view, a microspor-
angium (i) containing microspores ; C, a young microsporangium showing free mother cells
before formation of tetrads; D, tetrahedral division of spore mother cell; E, ripe megaspore;
F, four microspores of tetrad separated; G, microsporophyll seen from above showing ripe
microsporangium. — After Dodel-Port.

are borne in the axils of the leaves, the outer leaves bearing the
megasporangia and the inner leaves the microsporangia. The
gametophytes consist of but a few cells. While the group is het-

PRINCIPAL GROUPS OF PLANTS.

99

erosporous and the gametophytes resemble those in Selaginella, the
sperms are multiciliate and coiled as in the Ferns.

Distribution and Uses of Lycopodiales. — A number of the
Lycopodiums are common on rocks, damp woods, sandy bogs,
and illustrations of several of these are shown in Fig. 66. Some
tropical species are used in medicine ; the spores of Lycopodium
clavatum, on account of their fixed oil, are used as a dusting
powder, and for burning in the production of flash lights (see
Vol. II). The Selaginellas, of which there are several native
species, are commonly used for decorative purposes. Some species

FIG. 61. Longitudinal section of young embryo of a Selaginella before separation
from the prothallus: et, suspensor; w, root; f, foot; bl, cotyledons; lig, ligules or bud scales.
— After Pfeffer.

are, however, also used in medicine, and it is interesting to note
that the spores of one species (Selaginella selaginoides) are used
like those of Lycopodium.

While the Pteridophytes do not form a very conspicuous por-
tion of the flora at the present time and yield but few products
of use to man, it may be pointed out that in former ages they
formed the dominant vegetation of the earth. Many of the
ancestral forms of this group attained the size of trees and made
up the forest vegetation during the Devonian and Carboniferous
Ages, the latter being sometimes spoken of as the age of Pterido-
phytes. It is also called the Coal Age from the fact that the coal

100

A TEXT-BOOK OF BOTANY.

measures were chiefly laid down during this period. By some it is
thought that the deposits of coal of this age were probably princi-
pally formed from the remains of certain marsh plants including
two extinct groups of huge, tree-like club mosses (Lepidodendron
and Sigillaria) and the Calamites, representatives of the scouring
rushes.

SPERMOPHYTES.

The Spermophytes, or Seed Plants, constitute the third of the1
great divisions into which plants are divided. The plants belong-

PIG. 62. Successive stages in the germination of the microspores of a Selaginella:
p and w, cells of the prothallus; s, cells giving rise to sperms. A, B, D, views of spores from
the side; C, view from the back; in E, the cells surrounding the sperm mother cell are dis-
organized; F, two biciliate sperms. — After Belajeff.

ing to this division not only form the most conspicuous feature of
the flora because of their size and general distribution, but also
because of the fact that they produce flowers renders a large num-
ber of them especially attractive. The plants of this group are also
of great importance from an economic point of view. They fur-
nish a large part of the food of man and other animals, as well as
materials for clothing, shelter, fuel, and divers other purposes.
In this group of plants there are the highest differentiation of tis-
sues and the most complicated structure. The one character which
especially distinguishes them from the lower groups of plants
is that of the production of seeds.

PRINCIPAL GROUPS OF PLANTS. 101

The plants have for the most part well-differentiated stems
and leaves, and represent the sporophyte or asexual generation.
The sporophyte produces sporophylls which are of two kinds,
namely, megasporophylls and microsporophylls. The megasporo-
phylls bear small ellipsoidal bodies known as ovules, which develop
into seeds. The megasporangium is not separate and distinct in
the spermophytes as it is in Selaginella, but is embedded within an
ovule and corresponds to that part of the ovule known as the
nucellus. The nucellus encloses the embryo-sac, which is regarded
as a megaspore (Figs. 70, 71, and 81). Each megasporangium
(nucellus) therefore contains but a single megaspore, whereas in
Selaginella the megasporangia contain from I to 8 megaspores.
The microsporophyll bears microsporangia (pollen sacs) which
contain microspores (pollen grains). The female gametophyte in
the Spermophytes is still more limited in its development than
even in the highest Pteridophytes (as Selaginella and Isoetes)
and remains wholly within the megaspore or embryo-sac. As a
result of fertilization of the egg-cell an embryo is produced which
consists of root, stem, and one or more cotyledons and which with
the integuments covering it constitutes the seed.

Spermophytes embrace two well-defined groups, namely, (i)
Gymnosperms, or naked-seeded plants, and (2) Angiosperms, or
enclosed-seeded plants.

GYMNOSPERMS.

In the Gymnosperms the ovules, each of which contains a
megasporangium (nucellus), are borne on an open sporophyll
(carpel), and thus are exposed, as are also the seeds developed
from them. In the Angiosperms the ovules are borne within
closed sporophylls, and are thus protected or covered until the
seeds, which develop from them, mature.

The Gymnosperms represent an ancient group of plants and
were more numerous during the Triassic period than now. They
are mostly shrubs and trees, and do not shed their leaves period-
ically as the Angiosperms do, and hence are known as " ever-
greens." As in some of the Pteridophytes (Lycopodium, Equi-
setum), the sporophylls occur in groups forming cones or strobiles
(Fig. 72). They not only differ in external appearance from the

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A TEXT-BOOK OF BOTANY.

Angiosperms but also in the anatomical structure of the stem,
which is without large conducting vessels. In order to understand
the relation of the Gymnosperms to the Pteridophytes on the one
hand and to the Angiosperms on the other, it will be necessary to
consider briefly the life history of a representative group, such as
the Coniferae.

General Characters. — The seed consists essentially of three
parts, namely, a woody or leathery seed-coat, a nutritive layer
rich in oil known as the endosperm, and a straight embryo. The
latter is a more or less differentiated plantlet, consisting of a stem

spm

FIG. 63. The female gametophyte of a Selaginella; prothallus (pr) projecting through
the ruptured wall (spm) of the megaspore; ar, sterile archegonium; embi, emb2, two embryos
embedded in the tissue of the prothallus; et, et, suspensors. — After Pfeffer.

with a varying number of cotyledons or first leaves (2 to 16),
and a small root which is attached to a suspensor, as is the embryo
in Selaginella (Fig. 63). When the embryo begins its develop-
ment into the plant it uses up the nourishment with which it is
surrounded in the endosperm, and as it increases in size the seed-
coat is split. The root then protrudes and the cotyledons, to some
of which the seed-coat is still attached, are carried upward by the
stem through the surface of the soil, when the seed-coat is cast
off and the plant begins an independent existence. The first root
is the primary or tap root, and from this are sent out numerous
branches known as secondary roots, constituting a well-developed

PRINCIPAL GROUPS OF PLANTS. 103

root system which serves the double purpose of absorbing nutri-
ment from the substratum or soil and holding or fixing the plant
in its upright position. The embryonal stem grows vertically
upwards, continuing its growth indefinitely. Lateral branches
arise at more or less regular intervals which extend from near the
ground to the apex, the younger branches continually succeeding

FIG. 64. Bjrd's Nest Moss (Selaginella lepidophylla) . A, the plant growing in a
moist situation or upon the addition of water; B, the habit of the plant under dry conditions,
it unrolling and becoming as (A) upon the addition of water. This plant is also known
as Resurrection plant and Rose of Jericho, the latter name is more correctly applied to
Anastatica hierochuntica, a cruciferous plant of the East Mediterranean and Egypt, the
stems on drying becoming folded together and the whole plant being scattered by the wind.
The Bird's Nest Moss grows in Mexico and western Texas, and in the rolled-up condition
(B) is found occasionally in commerce and is used as a table decoration. It has the advan-
tage that even though it dries out, it may be renewed many times. — After Hieronymus
in Engler and Prantl.

the older ones from the ground upward, thus giving the trees
a cone-like outline. The leaves arise on the branches and are of
two kinds, primary leaves which are more or less scale-like and
deciduous, and secondary leaves which are true foliage leaves,
and are usually quite simple in structure. The leaves vary in
form but are usually narrow and somewhat thickened, giving
them a needle-like appearance.

104 A TEXT-BOOK OF BOTANY.

In addition, sporophylls (spore-bearing leaves) are formed at
the ends of the young shoots or in the axils of more mature ones

FlG. 65. A piece of slate from the coal formation in Shenandoah, Pennsylvania, showing
a fossil fern which is probably a species of Neuropteris.

(Fig. 69). These are compactly arranged, forming cones or stro-
bili which are always of two kinds and borne on different twigs
of the same plant or on different plants. The staminate cones

PRINCIPAL GROUPS OF PLANTS. 105

consisting of microsporophylls (stamens) are more or less elon-
gated and cylindrical or ovoid (Fig. 69, A). The carpellate
cones consisting of megasporophylls (carpels) have a shorter
longitudinal axis, and the cones vary considerably in the different
groups (Fig. 72).

FlG. 66. Several species of Lycopodium. i, Ground pine (L. ohscuruni) showing a
leafy branch with one strobile at the apex; 2, a branch of trailing Christmas green (L.
complanatum) bearing four or five strobiles at the apex of long dichotomously branching
stalks; 3, club moss or running pine (L. clavatum) with a branch bearing four strobiles;
4, shining club moss (L. lucidulum) with small sporangia borne in the axils of the leaves.

The Microsporophylls (Fig. 69) are usually of a yellowish-
brown color, and consist of a slender stalk and a lamina which
bears the microsporangia (pollen sacs) on the lower or dorsal
surface (Fig. 69, B, C). In this they show a resemblance to

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A TEXT-BOOK OF BOTANY.

FIG. 67. White Pine, also called Weymouth Pine, (Pinus Strobus).— From a photograph
by Mr. C. J. Hibbard in " Minnesota Trees and Shrubs."

PRINCIPAL GROUPS OF PLANTS.

107

ferns where the sori are borne on the under surface of the leaves.
The microsporangia vary in number from 2 to 15, and are pro-
tected in various ways, either being sunk in the tissues of the sporo-
jphyll, as in Pinus and Abies, or they are, as in Juniperus and
\Thuja, provided with a covering resembling the indusium of the
isori of the ferns. The walls are variously thickened and on drying,

>}f%2f

Dan

S.W

s.w

FIG. 68. Pinus reftexa. Transverse section of a portion from the inner face of the
spring wood showing a schizogenous resin duct or passage with the central canal (C) and
the thin-walled and resinous epithelium (ep); with parenchyma tracheids (t), the spring
wood (Sp. W.) and the summer wood (S. W.). — After Penhallow.

The Coniferae represent the most ancient group in which resin passages or reservoirs
are found. While these passages show certain important variations in structure and origin,
and while even in certain genera of the group, as in the genus Pinus, they exhibit consider-
able variation in detail, yet in this genus they are all of the same structural type as in Pinus
reflexa, the white pine of the high mountainous regions of New Mexico and Arizona. The
epithelial tissues are thin-walled and readily broken in making sections except in the hard
pines as the Loblolly pine (P. Tceda), where ths cells often become strongly resinous. (See
Penhallow's "Manual of the North American Gymnospenns.")

owing to unequal tension, the sacs are ruptured longitudinally
and the spores scattered. The microspores are very numerous,
sometimes forming powdery deposits. They are either i -celled
or 3-celled. In the latter case two lateral cells act as wings for
the dispersal of the spores by the wind (Fig. 69, D).

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A TEXT-BOOK OF BOTANY.

The Megasporophylls consist of sessile carpels (leaves) on
which are borne one or two naked ovules containing the sporangia
(nuclei). In certain groups, as in the pines, balsams, etc., a
scale is formed at the base of the carpel which bears the ovules,
and this scale is called the seminiferous scale. The ovules con-
sist of several parts (Figs. 70 and 71) : a stalk; an integument or
wall which has an opening at the apex known as the micropyle ;
a nucellus (megasporangium), being that portion next within the

FIG. 69. A, longitudinal section of cone composed of microsporophylls, of one of the
pines; B, longitudinal section of microsporophyll showing microsporangium (pollen sac);
C, the same in transverse section showing both microsporangia; D, winged microspore
(pollen grain), with a two-celled male gametophyte, the upper cell being the generative
cell, the remaining nucleated cell giving rise to the pollen tube. — After Schimper.

integument; and embedded within the nucellus a portion known
as the megaspore or embryo-sac.

Garnet ophytes. — The development of the garnet ophytes from
the asexual spores, namely, the microspore or pollen grain, and
the megaspore or embryo-sac, is as follows : The nucleus of the
megaspore divides repeatedly (Fig. 71), cell .walls are formed,
and a multicellular structure known as the ENDOSPERM is pro-
duced. This structure constitutes the prothallus of the female

PRINCIPAL GROUPS OF PLANTS.

109

gametophyte (Fig. 70, E; Fig. 71). In the upper portion of the
prothallus (that is, at the micropylar end), three to five archegonia
are formed (Fig. 70, a; Fig. 71), which are separated from one
another by cells of the endosperm or prothallus, which are rich in
protoplasm. The structure of the archegonium is much like that

n

FIG. 70. Longitudinal section of an ovule of a spruce (Piced): i, integument; nc,
nucellus (megasporangium) ; e, embryo-sac (megaspore) which has developed the female
gametophyte consisting of endosperm (e), two archegonia (a), which show the neck (c),
and the egg (n); p, germinating pollen grains (microspores) with pollen tubes (t) which
have penetrated the nucellus (nc) and reached the neck cells of the archegonia. — After
Schimper.

of the preceding group, consisting of a venter which contains the
egg, and a short neck composed of 4 to 8 cells.

The male gametophyte begins to develop while the pollen is
still in the sporangium. At this stage it consists of a generative
cell and a wall-cell, which constitute the antheridium, the cells of
the prothallus being usually suppressed (Fig. 69, D).

In addition to the extreme minuteness of the gametophytes

no

A TEXT-BOOK OF BOTANY.

we have also to note the character of the male gamete or sperm.
With the exception of the Cycads and Ginkgo, motile sperms are

FIG. 71. Development of gametophyte and embryo in one of the Coniferae. e, em-
bryo-sac (megaspore); a, archegonium ; h, neck of archegonium; i, integument; p, pollen-
tube; n, nucellus; f, wing of seed; g, fibrovascular tissue; kz, canal cells of archegonium;
ka, beginning of embryo; k, nuclei; ws.tip of root; wh, root-cap; c, cotyledons; v, point of
growth of stem; s, suspensor.

I, early stages of embryo-sac (e); II, young archegonium (a) after development of
neck cells (h), cell lumen (1); III, section of ovule with portion of attached seminiferous
scale (f) showing entrance of pollen tube; IV, embryo-sac with two developed archegonia;
V, archegonium after fertilization, there being four nuclei at the lower part, only two of
which are seen; VI, further development of embryo; VII, VIII, IX, X, showing develop-
ment of large tortuous suspensor, to which is attached the young embryo (ka); XI, XII,
mature embryo. — After Strasburger.

PRINCIPAL GROUPS OF PLANTS. in

not found in the Gymnosperms, but these are represented by two
male nuclei which are transferred directly to the archegonium
from the male gametophyte, formed through germination of the
microspore (pollen grain). It may be recalled that in the Pteri-
dophytes the motile sperms are discharged from the antheridium
and carried by the agency of water to the archegonium, but in the
Gymnosperms water is no longer a medium of transferral. The
microspores themselves are carried to the ovules usually through
the agency of wind, after which they germinate, developing a tube
which carries the male nuclei directly to the archegonium without
their ever having been free.

The transferral of the microspores or pollen grains to the
ovule is known as pollination. After pollination the wall-cell de-
velops a tube, the pollen tube, and the generative cell gives rise
to two male nuclei, which, with the remaining protoplasmic con-
tents of the antheridium, are carried by the pollen tube to the
micropyle, which it enters, penetrating the tissue of the nucellus
(Fig. 70, t). On reaching the neck of an archegonium the pollen
tube pushes its way down into the venter, where it discharges
one of the sperm nuclei, which unites with the egg, forming an
oospore. Cessation in growth does not yet take place and the
oospore develops into the embryo already described. The develop-
ing embryo obtains its nourishment by means of a suspensor
(Fig. 71, s), which also places the embryo in a favorable position.

There being several archegonia in an ovule (Figs. 70, 71), a
corresponding number of embryos may be formed, but rarely
more than one survives. While the embryo is developing, the
other tissues of the megaspore are likewise undergoing changes
leading to the maturity of the seed. The carpels and seminifer-
ous scales also continue to grow, and they usually become more or
less woody, forming the characteristic cones of the pines (Fig.
72), but may coalesce and become fleshy, producing the berry-like
fruits of Juniper (Fig. 75). The seed on germination gives rise
to the sporophyte (tree).

Groups of Gymnosperms. — There are several important
groups of Gymnosperms: (i) The Cycads or Fern Palms,
which are characteristic of tropical and sub-tropical countries.
The trunk does not branch as in the ordinary evergreens, and

112

A TEXT-BOOK OF BOTANY.

FIG. 72. Cones of some of the Coniferae. A, branch of Spruce Pine (Pinus echinata)
with two cones; B, from Pitch Pine (Picea excelsa); C, from Great Sugar Pine (Pinus Lam-
bertiand); D, from Black Spruce (Picea mariana); E, from the California Silver Fir (Abies
magnified); F, from Loblolly or Frankincense Pine (Pinus Tceda); G, branch of Pitch or
Torch Pine (Pinus rigida).

PRINCIPAL GROUPS OF PLANTS. 113

the leaves form a crown at the summit of the stem or trunk.
An important character of some of the Cycads is the production
of multiciliate sperms, as in the ferns, Equisetum and Isoetes.
(2) The Ginkgonaceae (to which belongs the Ginkgo or Maidenhair
Tree, which is extensively cultivated in China and Japan and is
found wild in China. It is very widely cultivated in this country,
owing to its ornamental foliage ; the staminate tree is preferable,
as the seeds of the pistillate tree have a very offensive odor. The
triangular shaped leaves occur in fascicles and the seeds are
berry-like. (3) The Coniferae is by far the most important group
and consists of two families, the Taxacese and the Pinaceae. To
the Taxaceae belongs Taxus, or yew, a low tree bearing flat, linear
leaves and a seed which is exposed and surrounded by the scarlet,
fleshy, aril-like disk or scale.

To the Pinacese belong most of our important Gymnosperms.

Pinus (Pine) is the most important genus (Figs. 67, 73, and
74). It is characterized by having needle-like leaves arranged
2 to 5 in a fascicle. The cone of the pine is usually woody, and
upon becoming dry splits open so as to release the winged seeds.
Perhaps the most valuable member of this genus is the white pine
(Fig. 67) which is found throughout the northern half of the
United States east of the Mississippi River. Its timber is light
brown or reddish, soft and fine-grained, but not very strong.
It is used extensively in rough building construction.

Pinus palustris, or long-leaved pine, is one of the most valuable
members of this group. It is the chief source of the terebinthinous
products of this country, and its wood contributes no small part
to the lumber industry. The long-leaved pine is tall, straight, has
a thin-scaled bark and a very hard, resinous wood. The stem
separates near the summit into several diverging branches, giving
the tree a flattened top. The leaves are in threes, rarely in fours,
from 10 to 15 inches long, and the cones are 6 to 10 inches long,
the scales being armed with short recurved spines. Other pines
yielding turpentine are Pinus Tada, loblolly pine ; Pinus hetero-
phylla, Cuban or swamp pine ; Pinus echinnata, short-leaved yellow
pine.

Tsuga canadensis (Hemlock) is a common tree of eastern
North America (Fig. 73). It attains a large size, and the delicate
8

114

A TEXT-BOOK OF BOTANY.

I!} ar? tat ana

FIG. 73. Leaves and cones of Balsam Fir (Abies balsamea), Larch (Larix laricind),
Douglas Fir or Douglas Spruce (Pseudotsuga taxifolia), White Pine (Pinus Strobus), Hem.
lock (Tsuga canadensis) , Spruce (Picea mariana), and Jack Pine (Pinus Banksiana) . — From
"Minnesota Trees and .Shrubs."

PRINCIPAL GROUPS OF PLANTS.

spray of its branches gives it a delicate beauty. Although its lum-
ber is not very strong nor durable, it is extensively used. The
bark is also used to an enormous extent in the manufacture of
heavy leather. In recent years many tanneries have been built in
the hemlock districts so as to be near the supply of bark. For
the finer grades of leather the hemlock bark is mixed with that of

"Pfltrohua

\rar auatnaca

F> u o u r9

1 monTana

FIG. 74. Cross-sections of leaves of six different species of Pinus, showing in the
diagrams the variation in the shapes of the cross-sections, with the distribution of the oil
reservoirs, and beneath each an enlarged view of the epidermal layer and underlying tissues.
—From "Minnesota Trees and Shrubs."

the oak, in order to avoid the reddish color produced by the
former. V.

Another important genus is Juniperus. The red cedar (/. vir-
giniana, also called Sabina virginiana} or savin is a tree producing
valuable fine-grained soft and durable wood which is used exten-
sively in making chests, pails, posts, etc. It is interesting to note
that this tree, which is frequently planted to form windbreaks,
develops the fungus Gymnosporangium in the form of cedar
apples, which in the secidial stage produce the leaf rust of apple.

u6

A TEXT-BOOK OF BOTANY.

The berries of the common juniper (/. communis) are sweet and
fleshy and are used medicinally as a diuretic and also in the
manufacture of gin.

FIG. 75. A branch of Red Cedar \Juniperus virginiana) with numerous berry-like cones.

PRINCIPAL GROUPS OF PLANTS. 117

Economic Uses of the Coniferae. — From an economic point
of view the Coniferse are by far the most important group of
plants thus far considered. In fact, they may be ranked first in the
production of valuable timber. Of those yielding timber the
following species may be mentioned : White pine (Pinus Strobus) ;
long- leaved, yellow, or Georgia pine (Pinus palustris Mill) ;
spruce pine (Pinus echinata) ; the Redwood of Upper California
(Sequoia sempervirens) ; pitch pine of New Mexico (Pinus pon-
der osa) ; the Scotch fir, the common pine of Europe (Pinus sylves-
tris). Some of the woods are adapted for special purposes: as
that of Pinus Celubra of the high mountains of Europe and
Northern Siberia, which is excellent for wood-carving; red cedar
(Juniperus virginiana) (Fig. 75) used in the making "of cigar
boxes and lead pencils; balsam fir (Abies balsamea) used in the
manufacture of wood pulp.

By reason of the oleoresinous constituents the woods of some
of the Coniferae are among the most durable known. A few
years ago Jeffrey examined a specimen of Sequoia Penhallowii
which was obtained from auriferous gravels of the Miocene in
the Sierra Nevada Mountains and found it to be in a very perfect
state of preservation. Penhallow (loc. cit.) considers this to be
the most ancient record of an uninfiltrated and unaltered wood.
Coleman, in 1898, found in the Pleistocene clays of the Don
Valley a specimen of red cedar (Juniperus virginiana} which not
only possessed all of the external characteristics of this species
but when sawed emitted the aromatic odor of the bark. In the
Pleistocene deposits of the western United States and Canada
are found more or less unaltered specimens of various species of
Juniperus, Pseudotsuga, Picea, and Larix.

Some of the pines yield edible seeds which have been used
by the Indians of Western America ; as the edible or " nut pine "
of California and New Mexico (Pinus edulis) ; Pinus monophylla,
discovered by Colonel Fremont in Northern California; Pinus
Jeffreyi of Northern California ; and Pinus Pinea of Europe, the
seeds of the latter being used like almonds and known as " pig-
none." The seeds of Pinus Lambertiana (Fig. 72, C) of Califor-
nia are baked before being used as a food. This latter species is
also known as the sugar pine, as it yields a manna-like product.

n8

A TEXT-BOOK OF BOTANY.

A manna is also yielded by Cedrus Libani and Larix decidua. The
latter is known as " Briancon Manna," and contains melizitose.
The bark of some species furnishes valuable tanning material, as
that of the hemlock spruce (Tsuga canadensis).

Tbui

FlG. 76. Fruiting twig of common Juniper (Juniperus communis) , of Red Cedar or
Savin (Juniperus virginiana), and young twig of White Cedar or Arbor Vitae (Thuja occiden-
talis). — From "Minnesota Trees and Shrubs."

The Coniferse yield large quantities of volatile oils, resins, and
allied products which are used both in medicine and the arts.
A number of them yield turpentine (see Vol. II). Larix decidua
of the Alps and Carpathian mountains yields Venice turpentine.
Abies balsamea is the source of Canada turpentine or balsam of

PRINCIPAL GROUPS OF PLANTS.

119

fir; Seudotanga tnucronata or Douglass Spruce (Red fir) is prob-
ably the source of a balsam resembling Canada turpentine and
which is known commercially as Oregon balsam. Picea Mariana
or black spruce yields spruce gum, largely used in the manufacture
of chewing gum, and is also the source of spruce beer. Picea
excelsa or Norway spruce yields Burgundy pitch. Abies alba,
white fir or silver fir yields the Strasburg turpentine. Canada
pitch is the resinous exudation from the common hemlock
( Tsuga canadensis) . Sandarac is yielded by Callitris quadrivalvis
found growing in Northwestern Africa. Volatile oils are yielded
by a number of the Coniferse, of which the following may be
mentioned : Juniperus Sabina yielding oil of savin ; Juniperus
communis yielding oil of juniper, both of which are used in medi-

FIG. 77. Microscopical view of fragments of wood found in the coal deposits of upper
Silesia, Prussia. — After Link, from article by Potonie on the origin of coal and petroleum
in Ber. d. d. pharm. Ges., 1907, p. 181.

cine. The remains of Coniferae (Picea, etc.) are often found as
fossils, as the fossil resin amber, which is used in the arts, and
on distillation yields a volatile oil having medicinal properties.

ANGIOSPERMS, General Characters. — They constitute the most
conspicuous portion of the flora, embrace the greatest variety of
forms, and are the most highly organized members of the plant
kingdom. They vary in size from diminutive plants like the
windflower to the giant oak which shelters it. They may accom-
plish their life work in a few months, as the common stramonium,
or they may persist for several hundred years, as the trees of our
primitive forests. They may inhabit dry desert regions, as the
Cacti and Chenopodiacese, or they may live wholly in water, as
the water lilies. In short, they show the greatest adaptability

I2O

A TEXT-BOOK OF BOTANY.

to their surroundings. But no matter how diversified they may
seem in form and structure, they agree in this with possibly one
exception, namely, mignonette, that the seeds are produced in a
closed carpel. This has been considered, as already indicated,
to be the chief difference between the Gymnosperms and Angio-
sperms.

The two groups are further distinguished by several other
important characters : (i) The carpel or carpels (megasporophyll)
is developed into an organ commonly known as a pistil (Fig. 78).
This organ consists of three parts, namely, ovary, style, and
stigma, the ovary enclosing the ovules. (2) In the Angiosperms
the megaspore (embryo-sac) develops a gametophyte which does

FIG. 78. A, longitudinal section through orange flower (Citrus Aurantium) showing
stalk (PE) ; sepals (s) ; petals (p) ; stamen with filament (F) and anther (A) ; compound
pistil (composed of united carpels) with stigma (T), style (Y) and superior ovary (O) with
ovules; disk or nectary (D). B, longitudinal section of a bud of clove (Caryophyllus)
showing inferior ovary (0), style (Y), stamens (F), petals (P), sepals (S), nectary (D).

not give rise to archegonia, but the egg arises directly from the
megaspore nucleus by a series of divisions. (3) The Micro-
sporophyll (stamen) differs considerably in structure and appear-
ance from that of the Gymnosperms. The stamen may be denned
as a leaf which bears sporangia (spore cases). It usually con-
sists of the following differential parts : filament and anther, the
latter consisting of pollen sacs (microsporangia) in which the
pollen grains (microspores) are developed (Figs. 78, 79, and 80).
(4) In a large number of cases in the Angiosperms there is
developed in addition to the sporophylls or sporangial leaves
(stamens and pistils) another series of leaves known as floral
leaves (Fig. 78). The latter usually are of two kinds, known as
sepals and petals.

PRINCIPAL GROUPS OF PLANTS. 121

The Development of the Two Generations, namely, the
sporophyte and gametophyte, is much the same in the Angio-
sperms as in the Gymnosperms; that is, the sporophyte consti-
tutes the plant body and what is commonly considered to be the
plant. The gametophytes are still more reduced than was the
case in the Gymnosperms, the male gametophyte consisting of
but two cells.

Beginning with the germination of the seed, we may outline
the life history of the plant as was done under Gymnosperms.
The seeds in the two groups are much alike, with the exception
that in the Angiosperms they usually have two integuments.
Within the Angiosperms two classes of embryos are distinguished,
which give rise to the most important division of this group of
plants. In the one case a single cotyledon is formed at the apex
of the stem, and all plants having an embryo of this kind are
known as MONOCOTYLEDONS, that is, plants having one seed leaf.
In the other case two cotyledons arise laterally on the stem and
opposite each other, and those plants having an embryo of this
type are grouped together as DICOTYLEDONS, or plants having two
seed leaves. In the monocotyledons the cotyledon is limited to one,
but in the dicotyledons the seed leaves are not limited in number
and there may sometimes be three or more.

The sporophyte which develops from the germinating seed
consists of the essential parts already given, i.e., root, stem, and
leaves. The leaves are of four kinds: (i) Foliage leaves, (2)
scale leaves or bud scales, (3) floral leaves, which in some cases
are wanting, and (4) sporangial leaves or sporophylls. Inasmuch
as the latter give rise to the gametophytes (male and female) the
development of the sporangia in each will be considered in detail.

The Microsporangia (pollen sacs) arise by the division of
certain cells under the epidermis of the anther (Fig. 79). This
process of division continues until four regions of fertile tissue
(sporangia) are produced (Fig. 79, D). The sporangia are
directly surrounded by a continuous layer of cells which consti-
tutes the tapetum or tapetal cells (Fig. 79, f), these being in the
nature of secretion cells and containing considerable oil. The
tapetum is in turn surrounded by a layer of cells which are
peculiarly thickened and which on drying assist in the opening

122

A TEXT-BOOK OF BOTANY.

of the anther and the discharge of the pollen, and this layer is
called the endothecium (Fig. 79, end). There is still a third or
external layer of cells, which constitutes the exothecium (Fig. 79,
ex). These four sporangial regions may remain more or less
distinct and separate at maturity, or the two on either side may

c.

fid

FIG. 79. Development of pollen sacs (microsporangia) in several of the Angiosperms:
A, showing beginning of archesporium (a), an outer sterile layer (b), position of connective
(con); B, later stage showing development of fibrovascular tissue (gf); C, longitudinal
section of archesporium; D, E, F, successive later stages showing in addition pollen mother
cells (sm) and tapetum layer (t). G, H, diagrammatic sections of mature pollen sacs show-
ing pollen mother cells (pm) , tapetum (t) , endothecium (end) , exothecium (ex) , and in H
longitudinal dehiscence with formation of what appears to be a unilocular pollen sac on
either side of the connective. — A-F, after Warming; G-H, after Baillon and Luerssen.

coalesce. This latter usually occurs at maturity, when dehiscence
takes place, forming apparently a single pollen sac on either side
of the connective or axis (Fig. 79, H).

The Microspores (pollen grains) are developed somewhat
differently in Monocotyledons and Dicotyledons. In most mono-

PRINCIPAL GROUPS OF PLANTS.

123

cotyledons the nucleus of each cell (pollen mother cell) making
up the archesporium divides into two nuclei, each of which takes
on a wall of cellulose. Each of these (daughter cells) in turn
divides, giving rise to four pollen grains. In dicotyledons (Fig.
80) the nucleus of a mother cell divides into four nuclei before
the walls are formed which separate the nuclei, thus giving rise
to the tetrad group of spores to which attention has already been
called (Fig. 60, D) under Bryophytes. The wall of each spore is
divided into two layers, an inner layer consisting of cellulose
known as the intine, which gives rise to the pollen tube on germi-
nation of the spore; and an outer layer somewhat different in

FIG. 80. Development of pollen grains (microspores) of garlic (Allium narcissi florum):
a., pollen mother cell with nucleus; b, the same with homogeneous nucleus and a thicker
wall; c-e, changes in nucleus prior to division; f, formation of spindle with nuclear masses
in the center from which nuclear threads extend to the poles of the spindle; g, division of
nuclear substance and receding of it from the center of the cell; h-i, further stages in the
organization of the nuclear substance at the poles; k, formation of a wall between two
daughter cells; 1, beginning of division of one daughter cell; m-n, final divisions resulting
in the formation of a tetrad (group of 4 cells). — After Strasburger.

composition and variously sculptured, known as the exine. When
the spores are mature the original walls of the cells of the arche-
sporium dissolve and the ripe pollen grains are set free, forming
a yellowish powdery mass filling the pollen sac. In some cases
the spores of the tetrads hang together, or even the whole mass
of pollen tetrads may be more or less agglutinated, as in the
orchids and milkweeds, these masses being known as pollinia.
Male Gametophyte. — Before the dispersal of the pollen grains
or microspores, certain changes leading to the development of
the gametophyte have taken place (Fig. 81). The spore, as we
have seen, is unicellular. This divides into two cells : one, which is
relatively small, known as the mother cell of the antheridium
(Fig. 81, v), and another, which, composed of the remaining

i24 A TEXT-BOOK OF BOTANY.

nucleus with the surrounding cell-contents, constitutes the tube- or
wall-cell of the antheridium.

Development of Ovule and Megasporangium (nucellus). —
The ovule at first develops as a small protuberance on the inner
surface of the ovary, after which it differentiates into (a) a stalk
or funiculus by which it is attached to the ovary, the tissue to
which it is attached being called the placenta; and (b) an upper
portion which becomes the ovule proper. The differentiation of
the tissues is in a general way as follows : ( I ) The cells beneath
the epidermis in the apical portion of the ovule go to make up the
megasporangium (nucellus) ; (2) the peripheral cells from below
the nucellus give rise to the integuments ; and (3) while the integu-
ments are developing the archesporium or mother cell of the

FlG. 81. Development of male gametophyte in an Angiosperm. I, pollen grain
(microspore) which has divided into the mother or generative cell (v) and a larger tube-cell
with nucleus (sk); II, appearance of pollen on treatment with osmic acid showing the
separation of the generative cell (v) from the wall of the pollen grain; o,at the right giving
a view of the generative cell with the nucleus embedded in the hyaline protoplasm; III,
showing the development of the tube-cell into the pollen tube which contains the two male
cells (nuclei) or gametes formed by the generative cell. — After Elfving.

embryo-sac (megaspore) is being formed within the nucellus near
the apex.

Female Gametophyte. — The archesporium divides into two
cells, the lower one of which repeatedly divides, finally giving
rise to the embryo-sac which is sunk in the tissues of the nucellus.
The nucleus of the embryo-sac divides and redivides until 8 cells
are produced (Figs. 82 and 83), which are separated into the fol-
lowing groups: (i) Three of the cells form a group lying at the
apex, the lower cell of the group being the egg or egg-cell, the other
two cells being known as synergids or helping cells. (2) At the
opposite end of the sac are three cells, known as antipodal cells,
which usually develop a wall of cellulose and do not seem to have
any special function. (3) Near the centre of the sac are the two
remaining nuclei, which unite to form a single nucleus, from

PRINCIPAL GROUPS OF PLANTS.

125

FIG. 82. Development of embryo-sac or megaspore in an Angiosperm. la, longi-
tudinal section through a young ovule. Ib, longitudinal section through a rudimentary
ovule before the formation of the integument, showing mother cell of the embryo-sac (mega-
spore) (em) and primary tapetal cell (t). II, later stage showing the two cells into which
the mother cell has divided, the nuclei of which are in the act of dividing. Ill, mother-
cell of the embryo-sac divided into four cells (sporogenous mass of cells) ; the lowest of these
cells (e) displaces the rest and becomes the embryo-sac in IV. IV, pek, is the primary
nucleus of the embryo-sac. V, two daughter cells resulting from the division of the nucleus
of the embryo-sac. VI, VII, show egg apparatus composed of two synergids (s) and the
oosphere (o), and antipodal cells (g). VIII, longitudinal section through a mature ovule
with the inner integument (ii), the outer integument (ai), the nucellus (n), the vascular
bundle (gf) entering the funiculus (f), and secondary nucleus in the embryo-sac (sek). —
After Strasburger.

126 A TEXT-BOOK OF BOTANY.

which after fertilization the endosperm is derived. The embryo-
sac, as it is organized at this stage, constitutes what is regarded
as the female gametophyte (Fig. 82). The undifrerentiated
embryo-sac constitutes the megaspore, which latter, after germina-
tion or differentiation into egg-cell and other cells, constitutes the
gametophyte. It is thus seen that in the female gametophyte
of the Angiosperm archegonia are apparently not formed. The
gametophyte, then, consists of the cell group containing the egg
and the remaining portion of the embryo-sac, which latter may
be compared to a prothallus. This comparison is not difficult to
understand if we bear in mind the structure of the gametophyte
in the Gymnosperms, and particularly if we recall the structure
in Selaginella and other higher Pteridophytes.

Fertilization. — While in the Gymnosperms the pollen grains
are usually provided with wings so as to bring about their trans-
ferral to the carpel by the agency of the wind, in the Angiosperms,
on the other hand, the grains are not provided with wings, but
are adapted to the transferral by insects. Pollination, however,
may be also effected by the wind, as is the case with many of our
forest trees. After the deposition of the pollen grain on the stigma,
the tube-cell begins to form a tubular process (pollen tube) which
carries the male nuclei to the egg-cell (Fig. 83, i). It pierces
the tissue of the stigma (Fig. 83, h) and traverses the style (Fig.
83, g) until it reaches the micropyle of the ovule, which it enters
(Fig. 83, m)y then reaching the nucellus it penetrates this, enter-
ing the embryo-sac. The tip of the tube breaks and one of the
generative nuclei which has been carried downward unites with the
egg, after which a wall is formed, giving rise to an oospore. The
oospore develops at once into the embryo or plantlet as seen in
the seed, this stage being followed by a period of rest. In fact,
the young plant may lie dormant in the seed for years.

Development of Seed. — The steps in the development of
the mature seed occur in the following order (Fig. 84). The
oospore divides into two parts, an upper portion which gives rise to
the embryo, and a lower portion which by transverse segmentation
gives rise to a short suspensor (Fig. 84, v} which practically serves
the same purpose as in the Gymnosperms (page HI). The em-
bryonal cell develops the embryo, which consists of: (l)a root por-

PRINCIPAL GROUPS OF PLANTS.

127

tion which is connected with the suspensor (Fig. 84, w) ; (2) one
or two cotyledons (Fig. 84, c) which are attached to the stem ; (3)
a little bud at the apex of the stem which is known as the plumule.
While the embryo is developing, the nucleus of the embryo-
sac, either after fusing with the prothallial cell of the pollen grain,
or in the absence of such union, begins active division, forming,

FIG. 83. Diagrammatic representation of fertilization in an Angiosperm. d, floral leaves;
stamen consisting of filament (c) and anthers (a,b), one of which (b) has dehisced, exhibiting
numerous pollen grains; e, nectar-secreting bodies; pistil consisting of ovary (f), style (g),
and stigma (h). On the latter pollen grains (i) are germinating, the tube (1) of one of them
has penetrated the tissues of the stigma and style, and entered the foramen (m), or opening
of the ovule. The ovule consists of several parts: raphe (n), outer integument (p), inner
integument (q), chalaza (o), nucellus (s), embryo-sac or megaspore (t) with egg-cell (z),
synergids (v), antipodal cells (u), and the nucleus in the center which gives rise to the
endosperm. — After Sachs.

a highly nutritive tissue rich in starch, oil, or proteins, known as
the endosperm (see chapter on Seed). Simultaneously with the
development of the endosperm the nucellus may give rise to a
nutritive layer called the perisperm, or the tissues of the nucellus
may be modified and form, with the altered integuments or coats
of the ovule, the seed-coat.

Inasmuch as the Angiosperms furnish by far the larger pro-
portion of plants and plant products used in medicine, it is desir-

128

A TEXT-BOOK OF BOTANY.

able to give particular attention to the morphology of this group,
as also to the distinguishing characters of a number of the impor-
tant families.

Economic Importance. — As indicating the great usefulness to
mankind of the products obtained from the Angiosperms it will be
sufficient to merely mention that all of our garden vegetables as

FIG. 84. Development of embryo in the shepherd's purse (Capsella Bursa-pastoris).
I -VI, various stages of development: Vb, apex of the root seen from below, i, i, 2, 2, the
first divisions of the apical cell of the pro-embryo (suspensor); h, h, cells from which the
primary root and root-cap are derived; v, the pro-embryo; c, cotyledons; s, apex of the
axis; w, root. — After Hanstein.

well as the great crops of cereals like wheat, corn, rye, etc. ; edible
fruits and seeds ; textile products, such as cotton, flax, etc. ; medic-
inal products ; timbers of various kinds, as oak, mahogany, walnut,
chestnut, cherry, etc., are furnished by this great group of plants.

EVOLUTION.

Contrary to a popular opinion, the idea of evolution is almost
as old as the human race. From the time when man began to
think about the things around him he could not help but see that

PRINCIPAL GROUPS OF PLANTS.

129

nothing was permanent, and he could not help but wonder how
both the inorganic and the organic world came to be as he found
them. The fact is, then, that for years the thinking element of the
human race has had a fairly clear conception of the idea of evolu-
tion; all they lacked was the proof. Nothing is more decidedly

FlG. 84A. Hypothetical tree of relationship and descent of the leading groups of plants.

— After Ganong.

wrong than the belief that Darwin first conceived the theory of
evolution. His renown only lies in the fact that he was one of
the first to suggest an explanation, and probably also because his
explanation came at a most opportune time and was worked up in
such a masterly way.
9

130 A TEXT-BOOK OF BOTANY.

The theory of evolution has as its basis the idea that the
existing species of plants and animals are the descendants of earlier
forms. It holds that there is an unbroken line of descent from
the beginning of life on the earth, but that during the long ages
the successive descendants gradually changed in appearance from
their ancestors until we find the forms of the present day.

Nearly all branches of biological science give evidence in
support of the theory of evolution. Embryology, for instance, has
shown that in its development the individual during its life, begin-
ning with the fertilization of the egg-cell, passes through a series
of stages which are thought to represent the same series of stages
through which the whole race before it passed. The develop-
ment of the individual (i.e., ontogeny) represents in a very brief
space of time the evolution of the race (i.e., phylogeny). In
other words, " ontogeny epitomizes phylogeny."

Another branch of science which is bringing forth new evi-
dence is the branch called paleontology. This subject has to do
with the study of fossil remains and with the time they existed
on the earth in the living state. It has been found that fossils from
the different series of formations that make up the earth's outer
crust represent a regular advancement from the very simplest types
to those which are most complicated, right up to the most recent
forms. In not a single instance has a highly developed form been
found in a layer of rocks representing an early stage in the earth's
history.

Every scientist of the present time, probably without exception,
believes in the theory of evolution, but there is a great diversity of
opinion as to how it should be explained. This diversity of
thought, instead of disproving the idea of evolution, is making its
truth more generally felt. The problem, then, which is confront-
ing the scientist is not to prove that evolution is a truth, but to
explain it; to show how new forms may arise from old ones, —
that is, to account for the origin of species. Among the many
explanations the following have become most conspicuous:

ENVIRONMENT. — It was naturally thought at first that the
natural conditions under which organic life developed must have
a certain effect upon the individual, thereby bringing about a cer-
tain modification which would be transmitted in successively

PRINCIPAL GROUPS OF PLANTS. 131

greater degree to those progeny living under the same conditions,
and so gradually give rise to a different species. This, of course,
assumes that any change induced by environment would be trans-
mitted to the offspring, to be retained so long as the environment
remained constant, an assumption which -is probably not far
from the truth. While it is admitted that changes in the environ-
ment may cause direct responses, yet it is doubtful whether they
are definite or permanent enough to produce new forms. Near
the end of the eighteenth century this explanation was supported
by Erasmus Darwin of England, St. Hilaire of France, and Goethe
of Germany.

USE AND DISUSE. — There is very little difference between this
explanation and the preceding one. Lamarck proposed, in the
early part of the nineteenth century, that the use or disuse of
organs would so modify them that the acquired differences would
be inherited by the offspring. But, here again, the proof depends
upon the transmission of acquired characters, and this is now
almost disproved.

NATURAL SELECTION. — In 1859 Darwin published his " Origin
of Species by Means of Natural Selection," and this single event
revolutionized science. In this book Darwin arranged an enor-
mous mass of facts gained through many travels, incessant obser-
vation, and prolonged experiments. He built up an argument in
such a convincing way as to immediately attract the attention of
the world, not only of scientists but of laymen. The theory of
natural selection has for its basis the idea that great competition
is continually taking place between individuals of the same species
and between the individuals of various species. This struggle for
existence results in the " survival of the fittest " and the destruc-
tion of the unfit. The idea that two plants or animals from the
same parent might vary slightly, suggested the belief that the
one which was better equipped for the struggle for existence
would survive and so transmit its desirable characteristics to its
offspring, and that the unfortunate one would not survive and
its undesirable characteristics would thus be lost to the race.

The objections to the theory of natural selection are of various
kinds, but the most serious is probably the fact that it is hard to
conceive how a very slight difference in character can be of advan-

132 A TEXT-BOOK OF BOTANY.

tage in a life and death struggle. Necessarily when natural selec-
tion first begins to operate on two individuals the differences must
be only slight and hardly sufficient to give one of them such a vital
advantage over the other.

MUTATION. — This explanation was offered in 1901 by Hugo
de Vries of Holland. The word mutation means a change. In
this sense it means a sudden change and has to do with the fact
that among the offspring of a certain individual may be found
one or more individuals markedly differing from the parent, so
much so as to be regarded in a few instances as a distinct species.
Moreover, these mutants, as they are called, continue to breed
true, thereby giving rise to what might very well be called a new
species. In the study of mutation many experiments have been
conducted by scientists and breeders.

MENDEL'S LAW. — In intimate relationship with the subject of
evolution is the question of heredity. In the middle of the last
century there lived an Austrian monk, Mendel by name, who ex-
perimented with the cultivation of peas and other plants in the
monastery garden. In his studies he discovered a certain law
underlying the transmission of characters in reproduction. This
law, which for many years lay hidden from the scientific world,
was recently brought to light and now forms the basis of most
of the recent breeding experiments and is of profound value in
the study of heredity. In the simplest case it is as follows: If
two different species, A and B, are crossed, the result is a hybrid
(AB) which combines certain characters of both parents. When
this hybrid propagates, the progeny splits up into three sets : one
resembling the hybrid parent (AB) ; and the other two sets re-
sembling the parent forms (A and B) that entered into the hybrid.
Mendel's law is a statement of the mathematical ratio expressed by
these three groups of forms derived from a " splitting " hybrid.
This means that in a series of generations initiated by a hybrid, ap-
proximately one-half of the individuals of each generation will
represent the hybrid mixture, one-fourth of the individuals will
represent one of the pure forms that entered into the hybrid, and
the remaining fourth will represent the other pure form. Of
course, the I : 2 : i ratio holds only when the one unit-character is
involved, and does not apply to the hybrids as a whole, as differ-
ent characteristics are generally inherited independently of others.

\

PRINCIPAL GROUPS OF PLANTS.

133 v-

\

It should be understood that the use^of hybrids in such experi-
mental work is simply a device to securt easy recognition of the
contributions of each parent to the progen}, For example, if red
and yellow races of corn are crossed, it is vefy simple to recognize
the color contribution of each parent to the hybrid progeny, when
it would be impossible to separate the contraction of two yellow
parents. The inference is, that what is yv& of hybrids is true of
forms produced in the ordinary way/so that laws of heredity
obtained from a study of hybrids/*nay be regarded as laws of
heredity in general. S

In the working out of MejX^l's law it has been observed that,
while one- fourth of the prog^y are like one parent, the remaining
three-fourths will all show fie characteristics of thet other parent,
although only one ofVt'rc renaming three-fourths wiH breed true.
That is to say that the hybrids) which make ur/half of the progeny,
look like one of the parents, ^ut all ^Jt3 not breed true to that
parent.

In this case the character of the true pure-strain parent
which marks the hybrids is said to be a dominant character, while
the character of the other pure-strain parent is said to be a recessive
character, because in the hybrids its presence can not be observed
and can be discovered only by breeding the hybrids.

It is only by experiment and breeding that dominant and
recessive characters can be determined. For instance, in the
culture of peas the character of being tall has been found to be
dominant over the character of being dwarf. This means that all
the hybrids will be tall, although one-fourth of their progeny will
be dwarf.

Again in the pea, the character of having a round seed is
found to be dominant over that of having a wrinkled seed. In
wheat the character of being beardless is dominant over that of
being bearded, and again the character of being susceptible to
rust is dominant over that of being immune to rust.

The infinite number of characters which complicates the study
of hybrids and the fact that in breeding it is sometimes the dom-
inant and sometimes the recessive character which is the desirable
one to maintain suggest at a glance the breadth and difficulty of
the problem.

CHAPTER II.

CELL-CC/NTENTS AND FORMS OF CELLS.
A TYPICAL livin' « be said to consist of a wall and a

protoplast (a unit o? .^Lm) , although it is often customar
to refer to the protopla^ alone as constituting the cell. 1 nis ijv
view of the fact that the. ADrotopiasni which makes up tlie'sub_
stance of the protoplast is the living substance of the pjg^
BfgjJ^s the protoplasm other substances are also fr^ .^ ^e
\ hence\in a general way the eel H may be said^'be composed
of a wall an& contents (cell-content^ Thewallj as wdl ag the
cell-contents, conVAsts of a number rf substances, and, as the cell-
contents are of primary importan:e jn tjle development of the
plant, their nature and conip^^Sn will be considered first.

Cell-contents. — With the distinction already made the cell-
contents may be grouped into two classes : ( I ) Protoplasmic, or
those in which the life-processes of the plant, or cell, are mani-
fested; and (2) non-protoplasmic, or those which are the direct or
indirect products of the protoplast. The first class includes the
protoplasm with its various differentiated parts, and the second,
the various carbohydrates (starches and sugars), calcium oxalate,
aleurone, tannin, oil, and a number of other substances.

PROTOPLASMIC CELL-CONTENTS.

Protoplasm. — Protoplasm occurs as a more or less semi-
fluid, slimy, granular, or foam-like substance, which lies close to
the walls of the cell as a relatively thin layer and surrounding a
large central cavity or vacuole filled with cell-sap, or it may be
distributed in the form of threads or bands forming a kind of net-
work enclosing smaller vacuoles. Protoplasm consists of two
comparatively well differentiated portions: (i) Certain more or
less distinct bodies which appear to have particular functions and
to which a great deal of study has been given, as the nucleus and
plastids; and (2) a less dense portion which may be looked upon
134

CELL-CONTENTS AND FORMS OF CELLS. 135

as the ground substance of the protoplast and which is now com-
monly referred to as the CYTOPLASM (see Frontispiece). These
differentiated bodies and the cytoplasm are intimately associated
and interdependent. The nucleus and cytoplasm are present in
all living cells, and it is through their special activities that cell

FIG. 85. Successive stages in nuclear and cell division, n, nucleolus; c, centre-spheres
s, chromosomes; sp, spindle fibers; A, B, C, division of chromosomes, i, cell with nucleus
containing nucleolus (n), and two centrospheres (c); 2, showing separation of nucleus
into distinct chromosomes (s) and the centrospheres at either pole of the nucleus; 3, forma-
tion of spindle fibers (sp); 4, longitudinal division of chromosomes; 5, division of the cen-
trospheres; 6, 7, 8, further stages in the development of the daughter nuclei ; 9, formation
of cell-wall whicn is completed in 10 giving rise to two new cells. — After Strasburger.

division takes place. When, in addition, plastids are present, con-
structive metabolism takes place, whereby complex substances are
formed from simpler ones.

Besides the nucleus and plastids other protoplasmic structures
are sometimes found embedded in the cytoplasm. These are the
CENTROSPHERES (Fig. 85, c), small spherical bodies that are

136 A TEXT-BOOK OF BOTANY.

associated with the nucleus and appear to be concerned in cell
division. There are, in fact, quite a number of minute bodies in
the cytoplasm which may be always present or only under certain
conditions, and which are grouped under the general name of

MICROSOMES Or MICROSOMATA.

Chemically protoplasm is an extremely complex substance, but
does not appear to have a definite molecular structure of its own,
being composed in large measure of proteins, a class of organic
compounds which always contain nitrogen, and frequently phos-
phorus and sulphur. The molecule of the proteins is large and
more or less unstable, and hence subject to rapid changes and a
variety of combinations, and it is to these interactions that the
vital activities of the plant are attributed.

Nucleus. — The nucleus consists of ( I ) a ground substance
in which is embedded (2) a network composed of threads con-
taining a granular material known as CHROMATIN, and (3) gen-
erally one or more spherical bodies called NUCLEOLES, the whole
being enclosed by (4) a delicate membrane (Fig. 85). The chro-
matin threads are readily stained by some of the aniline dyes, and
are mainly composed of nucleins (proteins) rich in phosphorus,
which by some writers are supposed to be essential constituents of
the nucleus and necessary to the life of the protoplast. Chroma-
tin is constant in the nucleus, and prior to cell division the threads
become organized into bodies of a definite number and shape
known as CHROMOSOMES (Fig. 85, s).

Plastids. — The plastids or chromatophores form a group of
differentiated protoplasmic bodies found in the cytoplasm ( Front-
ispiece) and are associated with it in the building up of complex
organic compounds, as starch, oil, and proteins. The term chro-
matophore means color-bearer, but applies also to those plastids
which may be colorless at one stage and pigmented at another.
Hence we may speak of colorless chromatophores. According
to the position of the cells in which these bodies occur and the
functions they perform, they vary in color — three distinct kinds
being recognized, (i) In the egg-cell and in the cells of roots,
rhizomes, and seeds the plastids are colorless and are called LEUCO-
PLASTIDS. (2) When they occur in cells which are more or less
exposed to light and produce the green pigment called chloro-

CELL-CONTENTS AND FORMS OF CELLS. 137

phyll, they are known as CHLOROPLASTIDS or chloroplasts. (3) In
other cases, independently of the position of the cells as to light
or darkness, the plastids develop a yellowish or orange-colored
principle, which may be termed chromophyll, and are known as
CHROMOPLASTIDS. Chloroplastids are found in all plants except
Fungi and non-chlorophyllous flowering plants, and chromoplas-
tids in all plants except Fungi. Plastids vary in form from more
or less spherical to polygonal or irregular-shaped bodies, and
they increase in number by simple fission. They suffer decom-
position much more readily than the nucleus, and are found in
dried material in a more or less altered condition.

Leucoplastids. — The chief function of the leucoplastids is
that of building up reserve starches or those stored by the plant
for food, and they may be best studied in the common potato
tuber, rhizome of iris, and the overground tubers of Phaius (Fig.
2, b). The reserve starches are formed by the leucoplastids from
sugar and other soluble carbohydrates.

The chloroplastids occur in all the green parts of plants
(see Frontispiece). They vary from 3 to n /*, in diameter and
are more or less spherical or lenticular in shape, except in the
Algae, where they are large and in the shape of bands or disks
(Figs. 8 and 9) , and generally spoken of as chromatophores. Chlo-
Toplastids are found in greater abundance in the cells near the
upper surface of the leaf than upon the under surface, the pro-
portion being about five to one. These grains, upon close exam-
ination, are found to consist of (i) a colorless stroma, or liquid,
in which are embedded (2) green granules; (3) colorless gran-
ules; (4) protein masses; (5) starch grains; and (6) a mem-
brane which surrounds the whole. The green granules are looked
upon as the photosynthetic bodies; the colorless grains are sup-
posed to assist in the storing of starch or in the production of
amylase, the conditions for these processes being directly opposite,
i.e., when photosynthesis is active, starch is stored, and when
this process is not going on, as at night, amylase is produced and
the starch is dissolved. The protein grains may be in the nature
of a reserve material of the plastid and probably are also formed
in connection with photosynthetic products.

While the protoplasm has been termed by Huxley " The phys-

138 A TEXT-BOOK OF BOTANY.

ical basis of life," the chloroplastid has been spoken of as the
mill which supplies the world with its food, for it is by the
process of photosynthesis that the energy of the sun is converted
into vital energy, and starch and other products formed, which
become not only the source of food for the plant itself, but also
the source of the food-supply of the animals which feed upon
plants. In other words, horse-power is derived from the energy
of the sun which is stored in the starch grains of the chloroplastids.

Chromoplastids. — In many cases, as in roots, like those of
carrot, or flowers and fruits, which are yellowish or orange-
colored, there is present a corresponding yellow pigment, and to
this class of pigments the name chromophyll may be applied.
Some of these pigments, as the carotin in carrot, have been iso-
lated in a crystalline condition (see Frontispiece, also Fig. 86).

Chromoplastids usually contain, as first pointed out by Schim-
per and Meyer, protein substances in the form of crystal-like
bodies ; starch-grains may also be present. The Chromoplastids
are very variable in shape and in other ways are markedly differ-
ent from the chloroplastids. They are more unstable than the
chloroplastids, and are formed in underground parts of the plant,
as in roots, as well as in parts exposed to the light, as in the flower.
Their formation frequently follows that of the chloroplastids, as
in the ripening of certain yellow fruits, such as apples, oranges,
persimmons, etc.

The PLASTID PIGMENTS are distinguished from all other color-
substances in the plant by the fact that they are insoluble in water
and soluble in ether, chloroform, and similar solvents. In fact,
they are but little affected by the usual chemical reagents under
ordinary conditions.

Apart from the difference in color, the yellow pigment (chro-
mophyll) is distinguished from the green (chlorophyll) by the
fact that the latter is said to contain nitrogen, and also by their
difference in behavior when examined spectroscopically, chloro-
phyll giving several distinct bands in the yellow and orange por-
tion of the spectrum, which are wanting in the spectrum of the
yellow principle.

CYTOLOGY, or the science of cell formation and cell life. Dur-
ing recent years considerable attention has been given by botanists

CELL-CONTENTS AND FORMS OF CELLS. 139

FIG. 86. Various forms of Chromoplastids: A, from the fruit of Bryonia dioica; B,
the fruit of the European mountain ash (Pyrus aucuparia); C, the petals of nasturtium
(Tropceolum majus); D, petals of Iris pseudacorus, E, petals of Tulipa Gesneriana; F, the
root of carrot (Daucus Carota). — After Dippel in "Das Mikroskop."

140 A TEXT-BOOK OF BOTANY.

to the studies of the protoplasmic structures of the cell, especially
the nucleus; the reason for this being that all of the vital phe-
nomena of which living organisms are capable have their origin
in these substances. The nucleus is regarded as a controlling
center of cell activity, for upon it all growth and development of
the cell depend, and it is the agent for the transmission of specific
qualities from one generation to another. Furthermore, cytolo-
gists look upon the chromatin material of the nucleus as being
the agent for the transmission of individual characters to offspring.
The reason for this is that in the male generative cell it is prac-
tically only the nucleus which fuses with the egg-cell, no other
substances entering into the union. The centrosomes are usually
apparent during the process of nuclear division and by some
are regarded as the controlling organ of cell division, hence they
are known as the dynamic centers of the cell. The functions of
the plastids and cytoplasms are largely, if not entirely, connected
with the synthesis, transportation, and dissociation of metabolic
substances.

NON-PROTOPLASMIC CELL-CONTENTS.

The non-protoplasmic constituents of plants may be said to
differ from the protoplasmic cell-contents in two important partic-
ulars, namely, structure and function. For convenience in con-
sidering them here, they may be grouped as follows:

(1) Those of definite form including (a) those which are
colloidal or crystalloidal, as starch and inulin; (b) those which
are crystalline, as the sugars, alkaloids, glucosides, calcium oxa-
late ; (c) composite bodies, as aleurone grains, which are made
up of a number of different substances.

(2) Those of more or less indefinite form, including tannin,
gums and mucilages, fixed and volatile oils, resins, gum-resins,
oleo-resins, balsams, caoutchouc, and also silica and calcium car-
bonate.

I. SUBSTANCES DEFINITE IN FORM.
COLLOIDAL OR CRYSTALLOIDAL.

Starch is the first visible product of photosynthesis, although
it is probable that simpler intermediate products are first formed.
This substance is formed in the chloroplastid (see Frontispiece)
and is known as ASSIMILATION STARCH. Starch grains are

CELL-CONTENTS AND FORMS OF CELLS. 141

FIG. 87. Successive stages in the development of starch grains, in Pellionia Daveauana
(A to N); and in the fruits of the potato plant, Solatium tuberosum (P to R). In A, two
plastids with a number of small starch grains; B, a plastid in which a single starch grain is
differentiated; C to L, successive stages of the development of a single grain, the plastid
body being shown on the surface (p); M, N, the development of several 2-compound starch
grains; P to R, the development of additional layers at right angles to the original grain. —
After Dippel in "Das Mikroskop."

usually found in the interior of the chloroplastid, but may attain
such a size that they burst through the boundary wall of the
plastid, which latter in the final stage of the growth of the starch
grain forms a crescent-shaped disk attached to one end of the

142

A TEXT-BOOK OF BOTANY.

grain, as in Pellionia. Starch is changed into soluble carbohy-
drates by the aid of ferments and probably other substances, and
in this form is transported to those portions of the plant requiring
food. The starch in the medullary rays and in other cells of the

§

FlG. 88. A, potato starch grains showing the excentral and circular point of origin
of growth, and lamellae; B, maranta starch grains showing fissured point of origin of growth,
and distinct lamellae; C, wheat starch grains showing indistinct point of origin of growth,
and lamellae; D, corn starch grains, which are more or less polygonal in outline and have a
3- to 5 -angled point of origin of growth.

wood and bark of plants is distinguished by being in the form
of rather small and nearly spherical grains. In rhizomes, tubers,
bulbs, and seeds the grains are, as a rule, quite large, and possess

CELL-CONTENTS AND FORMS OF CELLS. 143

more or less distinct characteristics for the plant in which they
are found. Starch of this kind is usually spoken of as RESERVE
STARCH (Fig. 87).

Occurrence of Starch. — Starch is found in most of the algae
and many of the mosses, as well as in the ferns and higher plants.
The amount of starch present in the tissues of plants varies.
In the grains of rice as much as 84.41 per cent, has been found.
This constituent also varies in amount according to the season
of the year. Rosenberg has observed that in certain perennial
plants there is an increase in the amount of starch during the
winter months, whereas in other plants it decreases or may entirely
disappear during this period. In the latter case, from six weeks

FIG. 89. A, starch grains of Iris floreniina showing peculiar horseshoe-like fissure
extending from point of origin of growth; B, irregular starch grains of calumba root; C,
peculiar beaked starch grains of ginger rhizome; D, starch grains of bean showing irregular
longitudinal fissures; E, compound starch grains of oat.

to two months in the spring are required for its re-formation,
and about an equal period is consumed in the fall in effecting its
solution.

Structure and Composition of Starch Grains. — The formula
which is generally accepted for starch is (C6H10O5)n, this being
recognized by Pfeffer, Tollens, and Mylius. It is supposed that
the molecule of starch is quite complex, it being composed of dif-
ferent single groups of C6H10O5 or multiples of the same. While
this formula may be accepted in a general way, still it has been
shown that there are at least two substances which enter into the
composition of the starch grain, and more recent studies tend
to show that it is in the nature of a sphero-crystalloid, resembling
inulin in some respects. Starch grains have an interesting struc-

144

A TEXT-BOOK OF BOTANY.

ture. They vary in shape from ovoid or spherical to polygonal,
and have a. more or less distinct marking known as the " hilum,"
" nucleus," or the POINT OF ORIGIN OF GROWTH. The substances
of which the grains are composed are arranged in concentric
layers or lamellae which are more or less characteristic and which
sometimes become more distinct on the application of certain
reagents (Fig. 90). The point of origin of growth and alternate
lamellae are stained by the use of gentian violet and other aniline
dyes, which may be taken to indicate that these layers contain a
colloidal substance somewhat res-embling a mucilage, while the

FIG. 90. Successive stages in the swelling and disintegration of starch grains in the
presence of water on the application of heat (6o°-7o° C.),or certain chemicals. Potato
starch i-.io; wheat starch iL-22.

alternating layers are stained with dilute iodine solutions and
are probably composed of soluble starch, this latter corresponding
to the a-amylose of Arthur Meyer or the granulose described
by Nageli. The peripheral layer of the grain appears to be a
distinct membrane. It is quite elastic, more or less porous, and
takes up stains readily.

While starch grains usually occur singly, they are not infre-
quently found in groups of two, three, or four grains, when they
are spoken of as two-, three-, or four-compound. In some of the

CELL-CONTENTS AND FORMS OF CELLS. 145

cereals, as rice and oat, they are loo-compound or more. The
individuals in compound grains are in some cases easily separated
from one another. This occurs frequently in microscopical prep-
arations, and is especially noticeable in the commercial starches.

The various commercial starches belong to the class of reserve
starches and may be distinguished by the following characteristics :

1 I ) The shape of the grain, which may be spherical, ellipsoidal,
ovoid, polygonal, or of some other characteristic form (Figs. 88
and 89).

(2) The size of the grain, which varies from I to 2 /* to
about 100 /A in diameter.

(3) The position of the point of origin of growth, which may
be central (Fig. 88, C, D) or excentral (Fig. 88, A,B). In some
cases there are apparently two points of origin of growth in a
single grain, and it is then spoken of as " half-compound," as occa-
sionally found in potato.

(4) The shape of the point of origin of growth, which may
be spherical, as in potato (Fig. 88, A} ; cross-shaped, as in
maranta (Fig. 88, B) ; a three- or five-angled fissure or cleft, as
in corn (Fig. 88, D), or indistinct or wanting, as in wheat (Fig.
88, C).

(5) The convergence of the lamellae, which may be either
toward the broad end of the grain, as in maranta (Fig. 88, B),
or toward the narrow end, as in potato (Fig. 88, A). In most
grains the lamellae are indistinct or wanting, as in wheat and corn
(Fig. 88, C,D).

(6) Behavior toward dilute iodine solutions, the color pro-
duced varying from a deep blue in most starches to a red or
yellowish-red, as in the amylodextrin grains of mace.

(7) The temperature (4S°~77° C.) at which the " kleister "
or paste is formed, and its consistency.

(8) The appearance as viewed by polarized light, the distinct-
ness of the cross, as well as the degree of color produced, varying
considerably as Nichol's prism is revolved (Fig. 91).

(9) Behavior toward various reagents, as chromic acid, cal-
cium nitrate, chlor-zinc-iodide, diastase, and various aniline stains,
showing peculiarities of both structure and composition (Fig. 90).
General Properties of Starch. — If starch is triturated with

10

146

A TEXT-BOOK OF BOTANY.

water and the mixture filtered, the filtrate does not give a reaction
with iodine solution ; if, on the other hand, the starch is previously
triturated with sand and then with water, the filtrate becomes blue

FIG. 91. Larger grains of various starches as viewed through the micro polariscope
when mounted in oil: A, potato (70-80 M); B, wheat (30—40 M); C, ginger (30-50 /«.); D,
galangal (45-55 M); E, calumba (40-60 M); F, zedoary (50-75 M)°, G, maranta (35-50 /«.)•
H, colchicum (10-20 /*); I, corn (20-25 /A); J, cassava (20-351* ); K, orris root (30-35 M)-

on the addition of iodine solution. It appears that in the latter
operation the wall of the grain is broken and the soluble starch
present in the grain is liberated.

CELL-CONTENTS AND FORMS OF CELLS. 147

If dry starch and iodine are triturated together no color or,
at the most, a faint blue color is produced; whereas, if a litt'c
water is added and the trituration repeated, a deep blue color is
immediately produced.

The blue color of starch solution and iodine disappears on the
application of heat, but slowly returns on cooling the solution,
but not with the same degree of intensity, part of the iodine
being volatilized.

When starch is heated with glycerin it dissolves, and if alco-
hol is added to the solution, a granular precipitate is formed which
is soluble in water, the solution giving a blue reaction with iodine.

When starch is heated with an excess of water at 100° C. for
even several weeks, dextrinization of the starch does not take
place ; i.e., the solution still gives a blue color with iodine. If, how-
ever, a mineral acid be added, it is quickly dextrinized, turning
violet-red, reddish, and yellowish with iodine; finally, maltose
and dextrose are produced, these giving no reaction with iodine,
but reducing Fehling's solution. The ferments and other chemi-
cals have a similar effect on starch.

When dry starch is heated at about 50° C. from 15 to 30 min-
utes the lamellae and crystalloidal structure become better defined
and the polarizing effects produced by the grains also become
more pronounced. When starch is mounted in a fixed oil, as
almond, the polarizing effects are more pronounced than when
it is mounted in water, but the inner structure is not usually
apparent, unless the starch has been previously heated. (For
literature on the starch grain see Kraemer, Bot. Gazette, Vol.
XXXIV, Nov., 1902 ; Ibid., Vol. XL, Oct., 1905 ; also Eighth In-
ternational Congress of Applied Chemistry, Vol. 17, p. 31.)

BOTANICAL DISTRIBUTION OF STARCH. — This constituent is
commonly present as a reserve material in a large number of
plants. The sources of the commercial starches are constantly
being extended. The commercial starches are chiefly obtained
from. one or more genera of the Gramineae, Marantaceae, Eu-
phorbiaceae, and Solanaceae. The following is a list of the fami-
lies yielding one or more economic products which contain
starch: Cycadaceae, Gramineae, Araceae, Liliaceae, Amaryllida-
ceae, Iridaceae, Musaceae, Zingiberaceae, Cannaceae, Marantaceae,

148 A TEXT-BOOK OF BOTANY.

Orchidaceae, Piperaceae, Fagaceae, Aristolochiaceae, Polygonaceae,
Phytolaccaceae, Nymphaeaceae, Ranunculaceae, Menispermaceae,
Myristicaceae, Lauraceae, Papaveraceae, Cruciferae, Rosaceae, Legu-
minosse, Geraniaceae, Rutaceae, Simarubaceae, Euphorbiaceae,
Celastraceae, Sapindaceae, Rhamnaceae, Malvaceae, Thymelaeaceae,
Punicaceae, Myrtaceas, Umbelli ferae, Loganiaceae, Apocynaceae,
Convolvulaceae, Solanaceae, Scrophulariaceae, Gesneraceae, Rubia-
ceae, Caprifoliaceae, Valerianaceae, and Cucurbitaceae.

PERCENTAGE OF STARCH IN PLANTS. — The amount of starch
in economic plants, especially those used for food, is very high,
being, on an average, much greater than that of any other con-
stituent except water. The percentage of starch, calculated on
dry material, in a number of foods and spices is here given : Bar-
ley, 5345 to 72.90; cardamom seed, 18.66 to 40.53; carrot, 0.87
to 0.92; chestnut, 37.31 to 47.93; chinquapin, 44.45; cinnamon,
10.44 to 65.72 ; cloves, 9.41 to 51.03 ; cocoa (cacao), 3.83 to 48.73 ;
corn, 36.72 to 77.54; ginger, 46.16 to 62.53; lentils, 45-375 mace,
26.77 to 56.11 ; millet, 56.70 to 74.40; nutmeg, 17.19 to 40.12 ; oak
acorns, 32.64; oats, 42.64 to 63.50; onion, n.oo to 29.39; peas,
50.02 to 57.59; pepper, 28.15 to 64.92; pimenta, 16.56 to 59.28;
potatoes (sweet), 8 to 78.59; potatoes (white), 25.00 to 75.00;
rice, 74.80 to 84.41 ; rye, 51.15 to 74.08; wheat, 53.66 to 76:51.

MANUFACTURE OF STARCH. — In the preparation of commer-
cial starches the object is to break the cells and separate the
starch grains, freeing the product from the other constituents of
the cell as much as possible. The preparation of potato starch
is exceedingly simple, as all that is necessary is to reduce the tubers
to a fine pulp, the starch grains being separated from the tissues
by means of a sieve. The water containing the starch is removed
to tanks, the separation of the starch being facilitated by the
addition of alum or sulphuric acid which coagulates the dissolved
protein substances. The starch is washed and dried over porous
bricks by exposure to air. It is then thoroughly dried in a hot
chamber, reduced to a powder, and sifted. One hundred pounds
of potatoes yield about 15 pounds of dry starch. It is said that
diseased tubers produce as good a quality of starch as the sound
tubers.

In the preparation of the cereal starches the gluten interferes

CELL-CONTENTS AND FORMS OF CELLS. 149

with their ready separation. The process is therefore modified
by either allowing the cereals to ferment, whereby the gluten
is rendered soluble and easily removed, or the flour is made into
a dough which is kneaded over running water, whereby the starch
grains are separated. The starch is subsequently purified by
washing and settling. It is dried by gentle heat and assumes the
columnar structure as seen in the more or less irregular particles
in the commercial product. One hundred pounds of wheat yield
from 55 to 59 pounds of starch, the fermentation process giving a
larger amount.

In the preparation of corn starch, a weak solution of sodium
hydrate is usually employed to facilitate the separation of the
starch. Sulphurous acid is also used. One hundred pounds of
corn yield 50 pounds of starch.

Rice starch is prepared by either an alkaline process or by an
acid process similar to that used in the manufacture of corn
starch, hydrochloric acid being employed instead of sulphurous
acid. Rice yields a greater percentage of starch than any of the
other raw materials, 100 pounds of the grain giving 70 per cent,
of starch.

Starch is used as a food and for various other industrial pur-
poses. The principal nutritive starches are sago, tapioca, and
corn. Maranta, or arrowroot starch, is largely employed in the
preparation of infant foods. Much of the dextrin of commerce
is prepared by the action of dilute acids upon potato starch.
Starch for laundry purposes is prepared from wheat. Rice starch
is largely used as a dusting-powder. Cassava starch has consider-
able advantages over the other starches in the making of nitro-
compounds, and is employed in the preparation of smokeless
powders.

PYRENOIDS. — In the chromatophores of a number of algae a
distinct body is observed. It is more or less of a lenticular
shape, stained a dark purple on the addition of iodine, and is
known as a Pyrenoid. It is not definitely known whether it is
a true cell organ having a function similar to the plastids in
manufacturing starch or whether it is merely a mass of complex
reserve substances. It can be differentiated readily into two
distinct portions: an inner, somewhat highly refracting and

ISO A TEXT-BOOK OF BOTANY.

consisting of protein matter, and an outer layer, consisting of a
number of starch grains. The studies of Baubier tend to show
that the pyrenoid is perfectly differentiated and independent of
the chromatophore, and that the starch is formed from a leuco-
plastid which surrounds a phyto-globulin or crystalloid at the
center. This would quite agree with the studies of Timberlake,
who observed the complete conversion of the pyrenoid into starch.
That the substances of the pyrenoid are in the nature of reserve
food materials, is apparent from the fact that the pyrenoid entirely
disappears in Hydrodictyon prior to spore formation, and that
it is afterward formed anew in the young cells, thus behaving
very much like a leucoplastid. Attention should also be directed
to the fact that in some of the unicellular and filamentous algse
the pyrenoid divides during the division of the cell, thus behaving
like other protoplasmic organs.

INULIN appears to be an isomer of starch and occurs in solution
in the cell-sap of parenchyma cells of stems and roots, being also
found in the medullary rays. It exists in greatest amounts during
the early fall and spring, being changed at other times to levulose.
In the Monocotyledons it is found in the Amaryllidaceae, Liliaceae,
etc. In the Dicotyledons it is characteristic of the Compositae,
but also occurs in the following: Asclepiadaceae, Bignoniaceae,
Cactaceae, Campanulacese, Capri foliaceae, Compositae, Cruciferae,
Droseraceae, Euphorbiaceae, Geraniaceae, Labiatae, Leguminosae,
Lythraceae, Magnoliaceae, Menispermaceae, Moraceae, Nepenth-
aceae, Passifloraceae, Ranunculaceae, Rubiaceae, Rutaceae, Salicaceae,
Santalaceae, Theaceae, Thymelaeaceae, Urticaceae, Valerianaceae,
Verbenaceae, Violaceae, etc.

According to Dragendorff, there are two forms of inulin ; one
of which is amorphous and easily soluble in water, and another
which is crystalline and difficultly soluble in water. The latter
is probably, however, a modification of the former, and it is not
unlikely that the various principles known as pseudoinulin, inu-
lenin, helianthenin, and synantherin are all modifications of inulin.

In examining fresh material (Fig. 92) the sections should be
mounted in as little water as is necessary to enclose the section.
If inulin is present it shows in the form of colorless, highly
refracting globules. The latter are usually relatively small and
tend to unite, forming one or more large globules. Upon increas-

CELL-CONTENTS AND FORMS OF CELLS. 151

ing the amount of water they dissolve and are diffused among the
other constituents. If fresh sections are mounted directly in
alcohol, or if to the original aqueous mount strong alcohol is
added, the inulin separates in the form of rod-like or needle-like
crystals, which strongly polarize light. If the plant material is
preserved for some days in 70 per cent, alcohol, the inulin separates
in the form of sphere-crystals which adhere to the walls of the cell.
This aggregate consists of concentric layers of radially arranged,
needle-shaped crystals, the structure of which is more apparent
upon the addition of either nitric acid or a solution of hydrated
chloral. The crystal mass is insoluble in glycerin and sparingly
soluble in cold water. It is soluble in warm water, warm solu-
tions of glycerin and water, acetic acid, mineral acids, chlor-
zinc-iodide, and ammoniacal solution of cupric oxide. With solu-
tions of the alkalies it dissolves with a lemon yellow color, and
with acetic acid the crystals dissolve, forming a greenish colored
solution which soon fades.

Tunmann (Ber. d. d. pharm. Ges., 1910, p. 577) has sug-
gested the use of a solution of pyrogallol as a distinctive re-
agent for the microscopic study of inulin. The solution con-
sists of o.ioo Gm. Pyrogallol, alcohol 5 c.c., and 5 c.c. of hydro-
chloric acid. Upon carefully heating sections treated with this
reagent the cells containing inulin are colored a violet red. A simi-
lar solution made with resorcin in place of pyrogallol colors inulin
a cinnabar red.

In taraxacum, inula, pyrethrum, and other drugs inulin occurs
in the form of an amorphous mass having a more or less angular
outline. The masses are highly refracting and probably consist
of aggregates of small crystals similar in appearance to those of
mannit found in commercial manna.

HESPERIDIN. — Although not a carbohydrate, hesperidin is of
wide occurrence and separates in the form of sphero-crystals re-
sembling inulin. It is a glucoside (C22H2GO12), and it would
appear, from the studies of Tunmann (Schweiz. Woch. f. Chem. u.
Pharm., 1909, p. 794), that, like inulin, there are several forms
of it. Hesperidin, like inulin, occurs in living cells in the form
of a more or less viscous fluid. Upon the addition of water,
alcohol, glycerin, or solutions of hydrated chloral it separates in

152

A TEXT-BOOK OF BOTANY.

the form of yellowish sphere-crystals. If the fresh plant material
is placed in alcohol the crystals separate in the form of large
needles, often forming branching tufts. When examined by
means of the micropolariscope, they polarize light more or less
strongly, depending upon how the crystals were prepared. Upon
quickly drying the plant material in which it occurs, hesperidin
separates in the form of irregular, slightly yellowish clumps, re-
sembling those of inulin found in the composite drugs of com-
merce. If the material is slowly dried, the crystals are decom-
posed. Crystals of hesperidin have been found in Citrus fruits ;

FIG. 92. Sphere-crystals of inulin. A, parenchyma cells of the root of chicory (Cicho-
rium Intybus) treated with alcohol: a, numerous small globules shortly after the addition
of alcohol; b, a somewhat later stage, showing the fusion of many of the small globules of
inulin; c, crystal formation in the globules after the alcohol has acted upon the cells for
24 hours. B, sphere-crystals resembling starch grains formed in the tubers of Dahlia vari-
abilis in alcoholic material: in b, the section has been treated with nitric acid, the crystal
aggregate showing a trichiten structure. — After Dippel in "Das Mikroskop."

the fruit of Cocculus laurifolius; the leaves of Buchu, and Pilo-
carpus ; species of Mentha, Hyssopus, Teucrium, Satureia, Tilia ;
Conium macula-turn; Scrophularia nodosa, and stamen hairs of
the flowers of Verbascum. The crystals are found especially
in the epidermal cells of bracts. The crystals in the hairs of the
flowers of Verbascum are usually referred to as a sugar, but,
according to the studies of Tunmann, are in the nature of a
hesperidin.

CELL-CONTENTS AND FORMS OF CELLS. 153

If sections are mounted in a small quantity of water and
the latter replaced with dilute glycerin, followed by concentrated
glycerin, then there separates in the cells a number of yellowish
globules which are highly refractive (Fig. 93) ; these globules
tend to unite in the center and very soon crystallize. The sphero-

FiG. 93. Hesperidin. A, B, formation of sphero-crystals in the epidermal cells of the
foliage leaves of Linden upon the addition of glycerin; in A the hesperidin occurs in highly
refracting globules, which in B have united in a large central globule in which a crystal-
aggregate has formed. C, crystals in stamen hair of the flower-bud of Verbascum. D,
crystals in the cells of the upper epidermis of Hyssopus officinalis. E, cells of the upper
epidermis of the foliage leaves of the Linden. — After Tunmann.

crystal consists of radiating needles, the aggregate frequently
being marked by concentric lamellae, the whole being surrounded
by a more or less mucilaginous wall (Fig. 93). As there are
other substances in the cell the sphero-aggregate may contain
some of these in the interstices. If the crystals are formed slowly
and in the cold they are apt' to be of a yellowish, or even dark
yellow, color, whereas if heat is employed and the crystallization

154 A TEXT-BOOK OF BOTANY.

is more rapid they are nearly colorless and dissolve readily. The
crystals of hesperidin are insoluble in water, alcohol, glycerin,
ether, chloroform, solutions of hydrated chloral, dilute sulphuric
acid and dilute or concentrated hydrochloric acid and nitric acid.
They are sparingly soluble in ammonia water and hot acetic acid.
Upon the addition of either dilute or concentrated solutions of
potassium hydroxide or sodium hydroxide, hesperidin dissolves,
forming a yellowish solution. With concentrated sulphuric acid
it gives a deep yellowish solution, which upon warming becomes
a reddish-brown. Sometimes hesperidin, as in the stamen hairs
of Verbascum, is colored with concentrated sulphuric acid only
a light yellow.

GLYCOGEN is a carbohydrate allied to amylo-dextrin and occurs
commonly as a reserve food material in the fungi and some
of the Cyanophycece. It usually occurs in the form of a more or
less amorphous mass in the hyphye of the fungi, but occasionally
is found in definite granules resembling starch. It is supposed
to arise in plastid bodies resembling leucoplastids, but its general
formation is controlled by the protoplasm. In yeast it is found
in large quantities, sometimes nearly filling the entire cell.

CRYSTALLINE SUBSTANCES.

The sugars constitute a group of crystalline principles of
wide distribution. They occur in the cell-sap, from which by
evaporation or on treatment with alcohol they may be crystallized
out. There are chemically two main groups: monosaccharoses
(formerly termed glucoses) and disaccharoses (formerly the
saccharoses). Under the former are included the simple sugars
containing two or more atoms of carbon and known as biose
(C2H4O2), etc. Among the pentoses (C5H10O5) are rhamnose,
a component of certain glucosides; fucose, found in fucus and
other brown algae, and chinovite, occurring in certain Cinchona
barks. The most important subdivision of the monosaccharoses
comprises the hexoses (C6H12O6), which include glucose and
fructose, and are widely distributed ; d-mannose, found in the
manna of Fraxinus Ornus and obtained by hydrolyzing cellulose,
especially the reserve cellulose in the seeds of the vegetable ivory.
Of the disaccharoses (C^H^On) cane-sugar is the most im-

CELL-CONTENTS AND FORMS OF CELLS. 155

portant. In this group are also included maltose, formed by the
action of diastase on starch and by the action of ferments on
glycogen; trehalose or mycose, found in the Oriental Trehala,
ergot, Boletus edulis, and other fungi ; melibiose, occurring in
Australian manna and in the molasses of sugar manufacture;
touranose, found in Venetian turpentine (obtained from Larix
europaa) and in Persian manna; and agavose, occurring in the
stalks of Agave americana.

Of the numerous sugars the following are likely to be met
with in the microscopical study of drugs and economic products :

Dextrose (grape-sugar or dextro-glucose) is found in sweet
fruits, the nectaries of the flowers, and stems and leaves of various
plants. It crystallizes in needles and varies in amount from I to 2
per cent, (in peaches), to 30 per cent, in certain varieties of
grapes. It also occurs in combination with other principles, form-
ing the glucosides.

Levulose (fructose, fruit-sugar, or levo-glucose) is associated
with dextrose, occurring in some instances even in larger quanti-
ties than the latter.

Sucrose (saccharose or cane-sugar j is found rather widely
distributed, as in the stems of corn, sorghum and the sugar-cane;
in roots, as the sugar-beet; in the sap of certain trees, as sugar-
maple and some of the palms ; in the nectaries and sap of certain
flowers, as fuchsia, caryophyllus, and some of the Cactaceae ; in
seeds, as almond and chestnut, and in various fruits, as figs, mel-
ons, apples, cherries. In some plants, as in sugar-cane, the yield is
as high as 20 per cent. It crystallizes in monoclinic prisms or
pyramids, and forms insoluble compounds with calcium and
strontium.

Maltose is found in the germinating grains of cereals (see
Malt) ; it forms colorless, needle-shaped crystals resembling those
of dextrose, and forms compounds with calcium, strontium, barium
and acetic acid.

Trehalose occurs in some fungi, as ergot and Amanita mus-
caria — the latter containing as much as 10 per cent, in the dried
plant.

Mannitol occurs in the form of needles or prisms and is found
in the manna of Fraxinus Ornus to the extent of 90 per cent. It

156

A TEXT-BOOK OF BOTANY.

is also found in some of the Umbelli ferae, as Apium graveolens,
some of the Fungi and sea-weeds, and is rather widely distributed
(Fig. 94).

Dulcitol, which is closely related to mannitol, is found in
Eiwnynius europccus and in most of the plants of the Scroph-
ulariaceae.

PERCENTAGE OF SUGAR IN PLANTS. — No analysis is necessary
to indicate that most fruits contain quite a large percentage of
sugar. The following figures show the amount of sugar in some
of the more common fruits, the per cent, being calculated on

FIG. 94. Orthorhombic crystals of Mannitol (Mannit) obtained from aqueous solutions:
A, large crystals; B, feathery aggregates of needles.

dry material: Apple, 33.16 to 87.73; apricot, 7.58 to 86.21;
banana, 6.20 to 21.90; blackberry, 32.67 to 40.17; cantaloupe,
0.27 to 11.98; cherry, 29.97 to 85.86; currant, 33.76 to 75.49;
fig, 10.00 to 29.90 ; gooseberry, 47.33 to 79.82 ; grape, including
raisin, 67.82 to 83.00; huckleberry, 12.60 to 46.87; orange, 36.48
to 66.91 ; peach, 6.69 to 74.07; plum, 15.25 to 78.70; prune, 32.04
to 69.46; pumpkin, 0.15 to 11.98; and raspberry, 14.93 to 47.50.

The following percentage of sugars is present in some of the
cereals, common vegetables, etc. : Asparagus, 0.45 to 3.47 ; barley,
5.82 to 8.73; beet (garden), 4.20 to 31.45; beet (sugar), 3.55 to
89.61 ; buckwheat, 1.42 to 1.67; carrot, 3.62 to 15.30; cauliflower,
1.22 to 7.40; chestnut, 5.22 to 8.52; cocoa (cacao), 2.77; coffee,
0.20 to 14.50; corn, 0.96 to 6.77; cucumber, 0.72 to 1.51;

CELL-CONTENTS AND FORMS OF CELLS. 157

lentils, 2.75; maple sap, 2 to 4; oats, 0.51 to 5.27; onions, 0.44
to 14.02; rye, 0.39 to 9.46; sorghum juice, 8.60 to 14.70; sugar-
cane juice, 16.00 to 18.10; spinach, 0.06 to 6.66 ; turnip (Swedish),
5.05 to 9.67; sweet potato, 0.32 to 8.42; tomato, 2.53 to 3.86;
vanilla, 7.07 to 9.10; wheat, 0.58 to 5.12.

HONEY-DEW is a pathological sugar formed as a result of
the stings of insects (Aphides and Coccideae) on the leaves of
certain trees. There are a number of trees the leaves of which,
during the summer time, are covered with a thin layer of sugar
solution. Among these may be mentioned the linden, tulip poplar,
and chestnut. Honey-dew may also be formed, according to
Bonnier, without the assistance of aphides, and may be seen oozing
out of the stomata. It may be formed in such quantities that
it may drip from trees, as in the so-called rain trees of the
Tropics (see Pfeffer, " Physiology of Plants ").

THE ORIGIN AND FORMATION OF CARBOHYDRATES. — The first
visible product of photosynthesis is starch, and this is sometimes
called photosynthetic starch. Investigations during recent years
seem to indicate that grape-sugar or dextrose is the basal photo-
synthate, and that from this starch is later formed in the plastid.
This sugar is called photosynthetic grape-sugar to distinguish it
from the grape-sugar found in the cell-sap of the grape, raisins,
figs, etc. There is no question but that in the plastids starch
is readily formed from glucose, and, vice versa, that the starch
in the plastids is readily changed through the agency of the
ferment, amylase, into grape-sugar.

There are four factors necessary for the formation of a photo-
synthetic carbohydrate (starch or glucose) by the chloroplastids :
(i) Light; and in this condition it is the energy of the red and
blue rays of sunlight which are necessary to bring about the
synthesis. (2) Carbon dioxide. This compound must be present
in about the normal proportions that we find it in the air, namely,
3 parts in 10,000. (3) Water is essential, and this is always pres-
ent in living cells. It is by the dissociation of the CO2 and H.O
and rearrangement of the atoms that carbohydrates are formed,
being either starch (C6H10O5) or glucose (C6H12O6), with oxy-
gen as a by-product. These interactions may be shown by the
following equations :

158 A TEXT-BOOK OF BOTANY.

6CO2 + 5H2O = C6H10O5 + 6O2.

(Starch)

6C02 + 6H20 = C6H1206 + 602.

(Glucose)

(4) Certain mineral substances must be present, although, appar-
ently, they take no part in the photosynthetic reaction. Bokorny
has shown that compounds of potassium are essential to bring
about the reactions above given.

Some form of iron has always been considered necessary for
the development of the green pigment or chlorophyll in the chloro-
plastid. While this element may seem to be necessary in water
culture, it is not always essential, particularly if plants are grown
under control conditions in sand. The development of chlorophyll
also requires the presence of oxygen. The activity of the chloro-
phyll apparatus is further influenced by other factors, viz., the
maintenance of a proper temperature. It is self-evident that there
is a minimum and maximum temperature at which photosynthesis
is scarcely perceptible, and that there is an optimum temperature
during which the activity of the chloroplastid is at its height.
The latter varies with different plants, depending on the climate
to which they are either indigenous or naturalized. In the Tropics
the optimum temperature is somewhat higher, while in the Arctic
regions it is much lower. In temperate climates the optimum
varies between 20° C. (68° F.) to 30° C. (86° F.).

From the facts just given it would appear that considerable
is known in regard to the conditions and the substances which are
concerned in the formation of photosynthetic products. On the
other hand, we know practically nothing of the successive steps in
the formation of either starch or glucose in the plant. Numerous
experiments have been conducted and a number of hypotheses
have been advanced. According to von Baeyer, the first step
in the process of photosynthesis is a reduction in the CO2, formalde-
hyde being formed, and this is then polymerized into a carbohy-
drate, which is finally changed into dextrose. This may be repre-
sented by the following equations :

C02 + H20— >-HCHO + 02
xHCHO=('CH2O)x
6(CHaO)=C6H1206

CELL-CONTENTS AND FORMS OF CELLS. 159

There are a number of other views which have been advanced.
Erlenmeyer, for instance, has suggested that instead of formalde-
hyde being first formed, formic acid is the first product of photo-
synthesis, hydrogen peroxide being liberated ; both of these then
are decomposed, formaldehyde being formed according to the
following equations :

C02 + H20 = HCOOH + H202
HCOOH + H2O2 = HCOH + H2O + O2

By the further condensation of formaldehyde as in the hy-
pothesis of von Baeyer, dextrose is formed. On the other hand,
Brown and Morris consider that the first carbohydrate formed is,
in reality, cane-sugar, and that from this, then, dextrose and
the other carbohydrates are formed.

Some very interesting experiments were conducted by Berthe-
lot (Compt. rend., 1898, 1900, etc.), who obtained both formic
acid and formaldehyde while working with a mixture of carbon
dioxide and hydrogen. Later he obtained a synthetic carbohy-
drate, which on warming had an odor of caramel. Furthermore,
when using an excess of carbon monoxide with hydrogen, Berthe-
lot obtained a substance closely related to oxy-cellulose. Lob
(Ber. d. d. pharm. Ges., 1907, p. 117) concludes that from formal-
dehyde, glycolic-aldehyde (x CHO.CH2OH) is formed; this is
then followed by the formation of glyceric-aldehyde (CH2OH.CH-
OH.COH), which is finally polymerized into a hexose as glucose,
or even a higher carbohydrate.

THE ALKALOIDS include a group of organic bases which possess
remarkable toxicological properties. They are compounds of car-
bon, hydrogen, and nitrogen ; oxygen is also usually present, except,
in the liquid or volatile alkaloids, in which it is wanting. They
are usually combined with some organic acid, as malic acid or
tannic acid. In many cases the alkaloids are combined with acids
that are peculiar to the genus, — e.g., aconitic acid in Aconitum,
meconic acid in Papaver, etc. They are found in a large number
of plants, especially among the Dicotyledons, and are rather char-
acteristic for certain families, as those of the genera Strychnos,
Cinchona, Erythroxylon, Papaver, etc. When present, alkaloids
may be found in any part of the plant, but usually they are most
abundant in certain definite regions, as roots, rhizomes, fruits,

160 A TEXT-BOOK OF BOTANY.

seeds, or leaves. Furthermore, the amount is greatest at certain
stages of development, as in the fully ripe seeds, more or less
immature fruits, during the resting periods of roots and rhizomes,
and in leaves when photosynthetic processes are most active.
They occur in greatest amount in those cells which are in a poten-
tial rather than an active condition, being associated with starch,
fixed oils, aleurone grains, and other reserve products in the
roots, rhizomes, and seeds. They are found in fruits in greatest
amount during the development of the seed, but after the maturing
of the latter they slowly disappear, as in the opium poppy and
conium.

The alkaloids probably arise in the protoplasm, although they
may also be formed from the decomposition of protein substances.
The fact that asparagine, a weak base, is usually present when
the proteins are being formed from the protoplasmic substances
and is also present when the proteins are being used in the growth
of the plant, as during the germination of seed, would seem to
indicate that both views are more or less tenable. The studies
of Lotsy on Cinchona showed that alkaloids are formed in con-
nection with photosynthetic processes and that they are subse-
quently stored for the use of the plant. On the other hand,
it is rather interesting to note that when cinchona trees are
grown in the hot-house they do not produce any quinine, and,
again, it is said that the conium growing in Scotland does not
contain any coniine. From these observations we must conclude
that alkaloids are produced only under certain conditions, and
that they are not essential metabolic substances. The fact that the
presence of alkaloids may be demonstrated in the thick-walled
cells of the endosperm in nux vomica has led some investigators
to conclude that they may arise in the cell-wall. The occurrence
of alkaloids at this point is due to their imbibition by the wall,
just as other soluble cell contents are absorbed, especially upon the
death of the cell.

MICROCHEMISTRY OF ALKALOIDS. — The alkaloids occur in
rather large quantities in a number of plants. Seldom do we
find them in the form of crystals in the plant cell. Crystals of the
alkaloid Piperine are not infrequently observed in the oil secre-
tion cells of the endosperm of Piper nigrum (Fig. 94, A). The

CELL-CONTENTS AND FORMS OF CELLS. 161

alkaloids form crystallizable salts and, in many instances, definite
double compounds. Nevertheless, not a great amount of progress
has been made in their detection and localization, either in the
living plant or in economic products. The reason for this is that
other substances, as calcium oxalate, may interfere with the
reactions forming crystals with the reagents, so that nothing
definite can be deduced. Then again, when an alkaloid is charac-
terized by certain color reactions, especially if a rose or violet
color is formed, it may be due to the reaction of the reagent with
carbohydrates or protein substance. For this reason practically

FIG. 94A. Crystals of Piperine: A, cells of endosperm showing a single oil cell (b) in
which crystals of piperine have separated; (a) starch bearing parenchyma. B, piperine
crystals separated from sections which have been first treated with alcohol, and to the oily
globules remaining after evaporating the alcohol, a drop of distilled water has been added.
In from fifteen to thirty minutes there separate needles, short rods and aggregates of
piperine. — After Molisch's work on Histochemie.

there are only a few instances where satisfactory results are
obtained in the study of alkaloids in plant tissues. These, for the
most part, have been obtained in connection with the dried mate-
rials of commerce. As it is very important that these studies
should be carried further, a few illustrations may be given.

Hydrastis contains two alkaloids in considerable quantities
which form definite salts with nitric and sulphuric acids. Fur-
thermore, this plant does not contain calcium oxalate, so that the
crystals formed upon the addition of mineral acids could not be of
either the nitrate or sulphate of calcium, and if in other respects
they corresponded to the sulphates and nitrates of the alkaloids
peculiar to hydrastis, then the crystals must be salts of the alka-
loids. If sections of the fresh rhizome of hydrastis or the moist-
ii

1 62

A TEXT-BOOK OF BOTANY.

ened drug are mounted directly in sulphuric acid, there separate
very soon small acicular or rod-shaped crystals of berberine and
hydrastine (Fig. 95). This is one of the most satisfactory of
microchemical tests of the alkaloids that is known, and Leuff has
shown that they can be readily determined even in the endosperm
cells in the seeds of hydrastis (Pharm. Post, 1913, p. 977).

Caffeine is an alkaloid which is rather widely distributed, and
its presence can be easily determined, in dried material as
coffee seeds, in several ways. ( i ) It may be sublimed, the long,

\

B

FIG. 95. Alkaloids in Hydrastis: A, prismatic crystals which separate after a time
on treatment of sections of the rhizome of hydrastis or its powder with sulphuric acid; B,
the separation of needle-shaped crystals of the sulphates of the alkaloids in the paren-
chyma cells of hydrastis upon treatment with sulphuric acid.

silky needles of caffeine being deposited upon a watch crystal
or a microscopic slide. (2) Similar crystals may separate from
aqueous or hydro-alcoholic mounts of the material. (3) The most
satisfactory method for the detection of caffeine is to form a
double salt with gold chloride, the crystals of which are very
characteristic (Fig. 96). The test may be applied to coffee seeds,
cola nuts, tea leaves, guarana, etc., as follows : Sections are placed
in strong hydrochloric acid and slightly heated ; then one or two
drops of a solution of gold chloride are added and the sections
pushed to one side, allowing the liquid to evaporate. Near the

CELL-CONTENTS AND FORMS OF CELLS. 163

edge of the residue branching groups of needles of caffeine gold
chloride separate. Cocaine is another alkaloid which forms char-
acteristic crystals, and the double salt of the chloride with palladous
chloride is very characteristic (Fig. 97). The crystals of the
latter may be prepared in the same manner as caffeine, except
that to the sections of coca leaves or the powdered material a
smaller quantity of hydrochloric acid is added.

FIG. 96. Caffeine gold chloride; crystals formed on the addition of a solution of gold
chloride to a dilute aqueous solution of caffeine.

PROPERTIES OF ALKALOIDS. — In the microchemical study of
the cell-contents it is important to bear in mind that the alkaloids
possess certain characteristic properties and give definite reactions
with the so-called " alkaloidal reagents." The alkaloids occur in
combinations with acids forming salts which are mostly soluble in
water or in alcohol, and consequently may be extracted by means
of these solvents. From the latter well-characterized crystals
may be easily formed. The free alkaloid may be separated from
solutions of their salts in water by the addition of alkalies, but it
is usually important that the solutions of the latter be not in
excess, as otherwise the separated alkaloids may dissolve. With

164

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few exceptions, as Berberine and Sanguinarine, they form mostly
colorless crystals. Among the alkaloidal reagents giving charac-
teristic precipitates the following may be mentioned. Phospho-
molybdic acid ( Sonnenschein's Reagent) gives with nearly all of
the alkaloids a yellow, insoluble amorphous precipitate. Potas-

FIG. 97. Cocaine: A, monoclinic crystals of cocaine; B, orthorhombic crystals of co-
caine hydrochloride ; C, monoclinic crystals of cocaine hydrochloride and palladous chloride;
D, skeleton aggregates of cocaine hydrochloride and palladous chloride.

sium mercuric iodide (Mayer's Reagent) precipitates many of
the alkaloids in even dilute solutions, the precipitates being usually
yellowish-white and more or less flocculent. Wagner's Reagent,
or iodine dissolved in a solution of potassium iodide, is another
reagent that precipitates nearly all the alkaloids. The precipi-
tates are of a reddish or reddish-brown color, and are more
readily formed in acidulated solutions. From alcoholic solutions

CELL-CONTENTS AND FORMS OF CELLS. 165

crystalline double compounds may be formed. Picric acid forms
characteristic crystals with a number of the alkaloids. Wormley's
Reagent, or a solution of bromine in hydrochloric acid, gives
definite microscopic crystals with some of the alkaloids, as atro-
pine, hyoscyamine, and veratrine. Auric chloride and platinic
chloride both form characteristic double salts with a number of
the alkaloids. There are a number of other reagents which are
used in the study of the localization of alkaloids in plants. Most
of these depend upon certain color reactions. While it is true
that the alkaloids give rather striking colors with certain reagents,
yet, as a rule, they are of little value except when the alkaloids
are in a pure condition. This same objection holds, but with some-
what less force, to the employment of the alkaloidal reagents
just mentioned.

FAMILIES YIELDING ALKALOIDS. — It is very difficult to deter-
mine from the literature of the analyses as to how widely distrib-
uted alkaloids are in plants. Time and again principles, which
give definite reactions with certain alkaloidal reagents, are subse-
quently shown to be other than alkaloids. In enumerating the
families in which alkaloids occur we do not mean to say that
they are lacking in the families not mentioned here. Alkaloids
are seldom found in the Cryptogams, being confined, with few
exceptions, to the poisonous fungi, as Amanita of the Agaricacae.
Among the Monocotyledons they are found in the Palmae and the
Liliaceae. They are more widely distributed in the Dicoty-
ledons, occurring in the following families : Piperaceae, Chenopo-
diaceae, Ranunculaceae, Berberidaceae, Menispermaceae, Lauraceae,
Papaveraceae,, Leguminosae, Erthroxylaceae, Rutaceae, Aquifolia-
ceae, Sapindaceae, Sterculiaceae, Punicaceae, Umbelli ferae, Logania-
ceae, Apocynaceae, Solanaceae, Rubiaceae, and Lobeliaceae.

THE AMOUNT OF ALKALOIDS in plants varies under different
climatic conditions and is also very much influenced by culti-
vation (see chapter on "Cultivation of Medicinal Plants").
For these reasons there is a wide range in the alkaloidal content of
drug products, and, as the alkaloids are among the most poisonous
constituents known, the various pharmacopoeias have set alkaloidal
standards. At the International Conference for the Unification of
Pharmacopoeial Formulae for Potent Medicaments held in Brtts-

166 A TEXT-BOOK OF BOTANY.

sels in 1902 a protocol was prepared designating the strength of
the various galenicals. Unfortunately, a standard for the alka-
loidal content of drugs was not also established, and consequently
in the several pharmacopoeias there is still some variation in drug
standards. For percentage of alkaloids in different drugs and their
variation, consult Volume II, treating of Pharmacognosy.

CHEMICAL CLASSIFICATION OF ALKALOIDS. — The chemical
study of the alkaloids shows that each plant contains not one but
a number of alkaloids, cinchona bark and the opium poppy yield-
ing not less than twenty different alkaloids. As their chemical
constitution is not well known, it is customary even for the chemist
to group them into certain natural classes, as the alkaloids of
conium, tobacco alkaloids, the cinchona alkaloids, opium alka-
loids, etc. They may also be grouped into certain fundamental
groups, according to their nuclear structure derived from their
probable constitution. While the natural classification may be
more convenient, it will be replaced by a classification based on
chemical constitution when our knowledge of this class of sub-
stances is extended. From studies thus far made the following
groups of alkaloids may be recognized :

PYRIDINE GROUP. — Alkaloids derived from pyridine (C5H5N)
are found in Conium maculatum, Piper nigrum, and other species
oi Piper, Trigonella Focnum gracum, Areca Catechu, Beta vul-
garis, Nicotiana Tabacum, Pilocarpus Jaborandi and other species
of Pilocarpus, Lupinus, Laburnum, and other genera of the
Leguminosa. This group includes the liquid or volatile alkaloids.

PYRROLIDINE GROUP. — Derivatives of Pyrrolidine (C4H8NH)
occur in Atropa, Hyoscyamus, Datura, Scopolia and other genera
of the Solanace<z, Erythroxylon Coca, and Punica Granatum.

QUINOLINE GROUP. — Alkaloids with a Quinoline nucleus
(C9H7N) are obtained from cinchona bark and nux vomica.

ISOQUINOLINE GROUP. — Isoquhioline is isomeric with quino-
line; alkaloids with this nucleus are found in the opium poppy,
Hydrastis canadensis, Berberis vulgaris, Menispermum canadense
and quite a number of genera in the closely related families of
Ranunculacece, as well as in some other plants.

PHENANTHRENE GROUP. — Morphine and codeine, closely re-

CELL-CONTENTS AND FORMS OF CELLS. 167

lated alkaloids in opium, probably contain the Phenanthrene
nucleus (C14H10).

PURINE GROUP. — Caffeine, the characteristic alkaloid of
coffee, tea, and guarana, as well as theobromine associated with
caffeine in cacao and kolanut, are derivatives of Purine (C5H4N).

AMINO-ACID GROUP. — Asparagine, or the monamide of aspartic
acid, is very widely distributed throughout the plant kingdom.

Consult J. W. Bruhl, " Die Pflanzen-Alkaloide " ; A. Pictet,
" The Vegetable Alkaloids," translation by H. C. Biddle ; O. A.
Oesterle, " Grundriss der Pharmakochemie."

ASPARAGINE (C4H8N2 + H2O) (/?-asparagine, the monamide of
aspartic acid) is an amido compound which is most widely distrib-
uted throughout the vegetable kingdom. It is found not only in
reserve organs as the tubers of the potato and dahlia, the roots
of althaea, belladonna, etc., and the seeds of the chestnut tree,
but it also occurs in young shoots as of asparagus and in peas,
beans, and other members of the Leguminosae. Asparagine has
also been detected in some of the fungi as the Agaricineae and cer-
tain of the Myxomycetes. Unlike certain derivatives of urea, it is
a plastic product playing a very important role in plant metabolism.
On account of its crystalline character and solubility in water,
it is classed among the translocatory substances, appearing not
only when proteins are being utilized by the plant, but when
they are being formed. The crystals of asparagine are formed
rather easily from the expressed juices of young shoots, and may
be obtained even in sections upon mounting them in glycerin.
The crystals vary in length from 0.3 mm. to 15 mm. (Fig. 98).

Asparagine occurs in two forms, one of which is laevorotatory
and the other dextro-rotatory; the former is the one usually
present in plants. At 17.5 ° C., I part of asparagine is soluble
in 47 parts of distilled water; at 98° C., I part is soluble in 1.9
parts of distilled water.

THE GLUCOSIDES or Glycosides are a class of plant substances
which under the influence of ferments split up into a number of
substances, one of which is always glucose (dextrose) or an analo-
gous compound. Van Rijn has proposed the class name Glykoside
for all substances of this group, restricting the name glucoside
to those which yield glucose on hydrolysis. The glucosides are

168

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always associated in the plant cell with the special ferments
which are capable of decomposing them. There are other sub-
stances which have the property of breaking up the glycosides,
viz., dilute acids and alkalies. Of the mineral acids, dilute
sulphuric acid and dilute hydrochloric acid are the most effective.
They do not, however, always produce the same results on the
same glucoside, as sometimes one acid works better than the
other. Some glucosides are hydrolyzed by the use of strong

FIG. 98. Microphotograph of the rhombic prisms of Asparagine (amido-succinamic
acid) , which is rather widely distributed in the vegetable kingdom. From aqueous solution
the smaller crystals are combinations of base and prism (a) ; one or both of the acute angles
may be truncated on the faces of the brachydome (b) ; in the larger crystals (c) the brachy-
dome is more developed and is either equidimensional or elongated on the a -axis.

organic acids, as oxalic acid and citric acid. In view of the fact
that most glucosides require the presence of water in addition
to the presence of the ferment to produce an interaction, they
are looked upon as ether or ester derivatives. This view is
strengthened by a careful study of the glucosides which have
been prepared synthetically, but it is not known in what manner
the glucoside is united with the other compounds making up the
natural glucosides.

CELL-CONTENTS AND FORMS OF CELLS. 169

DISTRIBUTION OF GLUCOSIDES. — This class of substances has
only been isolated in the Dicotyledons, being present in the Pina-
ceae, Gramineae, Liliaceae, Iridaceae, Salicaceae, Fagaceae, Moraceae,
Urticaceae, Proteaceae, Santalaceae, Polygonaceae, Caryophyllaceae,
Ranunculaceae, Magnoliaceae, Calycanthaceae, Anonaceae, Moni-
miaceae, Cruciferae, Saxif ragaceae, Rosacese, Leguminosae, Tropaeo-
laceae, Linaceae, Rutaceae, Simarubaceae, Polygalaceae, Anacar-
diaceae, Corynocarpaceae, Aquifoliaceae, Celastraceae, Hippocas-
tanaceae, Sapindaceae, Rhamnaceae, Vitaceae, Tiliaceae, Malvaceae,
Theaceae, Dipterocarpaceae, Cistaceae, Caricaceae, Datiscaceae,
Thymelaeaceae, Lythraceae, Punicaceae, Combretaceae, Myrtaceae,
Araliaceae, Ericaceae, Primulaceae, Sapotaceae, Oleaceae, Logania-
ceae, Gentianaceae, Apocynaceae, Asclepiadaceae, Convolvulaceae,
Hydrophyllaceae, Boraginaceae, Verbenaceae, Labiatae, Solanaceae,
Scrophulariaceae, Bignoniaceae, Orobanchaceae, Globulariaceae,
Rubiaceae, Caprifoliaceae, Cucurbitaceae, and Compositae.

CHEMICAL CLASSIFICATION. — The natural glucosides may be
grouped either according to the nature of the sugar formed on
hydrolysis or their probable organic derivatives. Most glucosides
yield either dextrose or rhamnose. (i) Of the dextrose-gluco-
sides the following may be mentioned : yEsculin, arnygdalin, arbu-
tin, coniferin, fraxin, gaultherin, gossypetin,' gynocardin, indican,
iridin, linamarin, phloridzin, populin, prulaurasin, ruberithrinic
acid, salicin, sambunigrin, saponarin, serotin, sinalbin, sinigrin,
and syringin. (2) Of the rhamnose-glucosides the following may
be mentioned: Baptism, datiscin, frangulin, fustin, glycyphyllin,
and quercitrin. (3) There are a few glucosides which yield
peculiar sugars, as apiin, which on hydrolysis gives apiose and
dextrose; barbaloin forms d-arabinose; convolvulin yields rho-
deose and dextrose ; digitalin forms digitalose and dextrose ;
digitonin forms galactose and dextrose; digitoxin yields digi-
toxose; gentiin yields xylose and dextrose; hesperidin forms
rhamnose and dextrose, which are also formed from naringin and
rutin ; robinin forms galactose and rhamnose ; strophanthin yields
rhamnose and mannose ; vicianin forms arabinose and dextrose ;
and xanthorhamnin yields galactose and rhamnose.

Rosenthaler (Pharm. Zentralh., 1907, p. 94) has attempted
to group the glucosides, according to the constitution of the non-

1 70 A TEXT-BOOK OF BOTANY.

sugar substance formed on the hydrolysis of the glucoside. He
has given the non-sugar substances the class name of " Aglykone,"
and groups the glucosides accordingly into the following three
classes: I. Glucosides without Nitrogen Aglykones. II. Gluco-
sides with Nitrogen Aglykones. III. Glucosides with Nitrogen
and Sulphur Aglykones. Class I are further subdivided into
whether they yield alipathic, aromatic, or other derivatives ; each
of these again is further subdivided into a number of subgroups.
Among the alipathic aglykones are included the glucosides, jalapin
and convolvulin. The glucosides with aromatic aglykones are
subdivided as follows: (A) Those yielding benzol derivatives
and include arbutin, salicin, populin, gaultherin, etc. (B) Deriva-
tives containing the styrol nucleus include coniferin, daphnin, ses-
culin, scopolin, fraxin, naringin, and hesperidin. (C) Derivatives
containing anthracene in their constitution, as f rangulin, morindin,
and the glucosides of emodin, rhein, etc. (D) Glucosides which
are derivatives of flavon include apiin, fustin, quercitrin, rutin,
xanthorrhannin. II. The glucosides with Nitrogen Aglykones
include a number of cyanogenetic glucosides, of which amygdalin
is the representative. III. The glucosides with Nitrogen and
Sulphur Aglykones include sinigrin and sinalbin found in the
genus Sinapis and other genera of the Cruciferae. (Consult
J. J. L. van Rijn, " Die Glykoside " ; O. A. Oesterle, " Grundriss
der Pharmakochemie.")

PROPERTIES OF THE GLUCOSIDES. — Like the alkaloids, some of
the glucosides are highly toxic. Among those that possess a high
degree of toxicity may be mentioned convallamarin, digitalin, scil-
lain, strophanthin, sapotoxin, etc. They are soluble in water,
alcohol, ethyl acetate, and chloroform, and insoluble in ether. The
aqueous solutions are neutral or but faintly acid. Glucosides
may be separated from solutions of salts of the alkaloids owing
to the fact that they are soluble in chloroform and some other
of the immiscible solvents, providing the solution is slightly acid.
Most of the glucosides form well-developed crystals and may be
studied with a petrographical microscope (Fig. 99). There is
no special class of reagents, as with the alkaloids, used in their
detection ; on the other hand, some of them give strikingly
distinct color reactions whereby they may be detected in the

FIG. 99. Salicin. Orthorhombic crystals from alcoholic solution.

FIG. 100. Cocaine hydrochloride. Aggregates from aqueous solution.

CRYSTALS IN POLARIZED LIGHT (Crossed nicols).

CELL-CONTENTS AND FORMS OF CELLS. 171

tissues of the plant. With very few exceptions, however, the
color reactions are not satisfactory.

MICRO-CHEMISTRY OF GLUCOSIDES. — Although the glucosides
upon extraction from the plant tissues form well-defined crystals
(Fig. 99), they have not been identified as such in the plant.
A few have been identified by giving distinct color reactions with
certain reagents. The glucoside strophanthin can be detected in
the seeds of Strophanthus hispidus. This glucoside is colored a
brilliant green with sulphuric acid and is confined to the cells of
the endosperm. The test is carried out as follows: Sections
are mounted first in water and then transferred to a drop of
sulphuric acid contained on the same slide, when the cells con-
taining strophanthin are colored a bright green. Saponin is an-
other glucoside which, it is stated, may be readily detected in
plant cells, giving a reddish color reaction with sulphuric acid.
Lafon's reagent also may be applied for the detection of saponin ;
this consists in the use of two solutions: (a) equal volumes of
alcohol and sulphuric acid; (b) a very dilute solution of ferric
chloride. The sections are placed in solutions (a) and then a
drop of solution (b) is added. Cells containing saponin are col-
ored red, changing to violet, becoming brownish-blue, or brown
upon the addition of ferric chloride. Coniferin, the glucoside
found in the cells of pine and other Coniferous trees, is colored
red with sulphuric acid ; it also gives a characteristic reaction on
treatment of the section first with phenol, followed by sulphuric
acid or hydrochloric acid, it becoming a deep blue almost instantly.

THE SAPONINS are a group of glucosides which possess the
common property of forming a froth on shaking their aqueous
solutions, and are present in the " soap-plants," which have
been widely used as detergents. The saponins also dissolve the
red blood-corpuscles, and for this reason are considered to be
toxic substances. They have been found in the cell-sap of a large
number of plants, occurring in parenchyma cells and medullary
rays of roots and stems, the secretion cells and secretion reser-
voirs of leaves, and all parts of fruits and seeds. A large number
of principles have been isolated from different plants, some of
these being given distinct names, but the majority of them are
homologous substances having the general formula CnH2n_8O10.

172 A TEXT-BOOK OF BOTANY.

On account of some of the saponin-containing plants being added
to beverages and used as emulsifying agents, the toxicity of a
number of the saponins has been studied, those which are highly
poisonous being known as sapotoxins. The following are some
of the plants which contain sapotoxin: Quillaja Saponaria (9 per
cent.), Agrostemma Githago (6.5 per cent.), Saponaria officinalis
(4 to 5 per cent), and Poly gala Senega (2.5 per cent.).

Saponins have been found in more than a hundred different
plants, including one or more genera of the following families:
Liliaceae, Dioscoreaceae, Araceae, Chenopodiaceae, Phytolaccaceae,
Caryophyllaceae, Berberidaceae, Magnoliaceae, Ranunculaceae,
Bixaceae, Theaceae, Rutaceae, Zygophyllaceae, Meliaceae, Simaru-
baceae, Sapindaceae, Hippocastanaceae, Melianthaceae, Polygalaceae,
Pittosporaceae, Rhamnaceae, Saxifragaceae, Passifloraceae, Big-
noniaceae, Myrtaceae, Rosaceae, Leguminosae, Primulaceae, Sapo-
taceae, Oleaceae, Solanaceae, Scrophulariaceae, Rubiaceae, and
Compositae.

'Gluco-alkaloids represent a class of compounds intermediate
between the alkaloids and glucosides, possessing characteristics
of each. To this class belong achilleine, found in various species
of Achillea, and also solanine, found in a number of species of
Solanum.

FUNCTIONS OF ALKALOIDS AND GLUCOSIDES. — In the growth
of the plant there must not only be an adaptation to the external
conditions and provision made to protect the plant against tem-
pests, drought, excessive light, extreme temperatures, etc., but
the plant must protect itself from diseases as well as from the
depredations of animals. As a rule, plants, particularly of the
tropics, depend on their own power to repair any injury to which
they may be subjected. Nevertheless, there are many plants
which produce poisonous substances, and these are usually sup-
posed to have the function of protecting them from various dis-
eases, as well as attack by herbivorous animals. Many of the
alkaloids and glucosides are apparently aplastic substances, — i.e.,
are formed either occasionally or continually as unavoidable by-
products of metabolism, or are produced for special purposes.
Some of these principles, as asparagine, an alkaloid, and hesperi-

CELL-CONTENTS AND FORMS OF CELLS. 173

din, a glucoside, are not only products of constructive metabolism,
but are entirely reassimilated.

SUBLIMABLE PRINCIPLES. — Quite a number of plant principles
are capable of being sublimed. Not only is this true when they are
in- the pure state, but also when they are associated with other
compounds in the plant cell. This fact is of very great interest in
the examination of commercial articles and also in the study of
the localization and distribution of plant constituents. The method
of procedure is very simple, and a small quantity of material
only is necessary, usually from 0.020 to 0.050 Gm. being required.
In the study of leaves a fragment about 10 square millimeters is
sufficient. The material is dried, either cut up or more or less
comminuted and placed in a small watch crystal, the latter being
covered either with a slide or another watch crystal for the deposi-
tion of the sublimate. The watch crystal containing the material
is carefully heated either on a sand bath or on a bath containing
sulphuric acid (Figs. 101 to 104).

Rosenthaler (Ber. d. d. pharm. Ges., 1911, p. 338) has sug-
gested in the examination of powdered drugs a specially con-
structed apparatus. A small quantity of the powder is intro-
duced by means of a long funnel into a suitable tube, so that n®ne
of it comes into contact with the side walls. The powder should be
covered with a layer of asbestos to prevent any of it being carried
up mechanically. The tube is closed with a rubber stopper having
two holes, one of which carries a doubly bent tube leading to a
small vessel acting as a receiver, the other carrying a tube con-
nected with an air-pump. The air is exhausted and the tube con-
taining the drug is heated in a bath of sulphuric acid or paraffin.
A sublimate will form in the upper part of the tube containing
the material, and distillation products will pass into the tube
acting as a receiver and can be tested with various solvents and
reagents. Plants containing thein, vanillin, and cumarin may be
examined by direct sublimation in a watch crystal. Substances
which yield tarry distillate, as cinchona, hydrastis, piper, etc.,
probably are better examined using the apparatus described by
Rosenthaler.

Tunmann (Ber. d. d. pharm. Ges., 1911, p. 312) examined a
number of plants of the Ericaceae and found, by the microsublima-

174

A TEXT-BOOK OF BOTANY.

tion method, that they contained arbutin. The latter is a rather
widely distributed glucoside in this family and yields upon treat-
ment with solutions of emulsin or hydrochloric acid the sublimable
principle hydrochinon. The latter forms prisms and plates and
may be further examined with acetone solution, dilute solutions of

FlG. 10 1. Alkaloids of hydrastis obtained by microsublimation. The method fol-
lowed by Tunmann is to mix from o.oio to 0.050 Gm. of powdered hydrastis with a drop of
water upon a glass slide and heat to a temperature of 80° to 95° C. The sublimate consists
of a number of radiating particles in which different types of crystals very soon separate (A).
The microsublimate may be further treated with alcohol and a solution of potassium iodide,
when crystals of hydrastine (B) and needle-shaped crystals of berberine (C) form. — After
Tunmann in Gehe & Co.'s Handelsbericht, 1912.

ferric chloride and ammonia water. Arbutin occurs in the
leaves of Arctostaphylos Uva-ursi, Vaccinlum Myrtillus, Kalmia
angustifolia, and Pyrola rotundifolia.

Rosenthaler obtained definite crystals in the microsublimation
or pyro-analysis of the following drugs : cinchona, uva-ursi, f ran-

CELL-CONTENTS AND FORMS OF CELLS. 175

gula, rhamnus purshianus, rheum, hydrastis, opium, cubeba, piper,
anisum, senna, radix scammoniae, chrysarobium, rheum rhaponti-

FIG. 102. Microsublimate crystals of alkaloids in hydrastis: A, White crystals of
hydrastine formed upon the addition of chloroform to the sublimate. B, Type crystals
obtained on the microsublimation of pure hydrastine hydrochloride. C, Type crystals
obtained on the microsublimation of pure hydrastinine hydrochloride. D, Crystals of
hydrastine formed upon the addition of water to the amorphous and crystalline sublimate
obtained in the heating of powdered hydrastis. E, Resublimed crystals of hydrastin
obtained from the chloroformic solution of the microsublimate. — After Tunmann in Gehe
fe Co.'s Handelsbericht, 1912.

cum, jalapa, coca, stramonium, kamala, cousso, aurantii fructus
cortex, guarana, cacao, kola, cantharides, podophyllum, radix
canaigre, and kava-kava. (Consult Figs. 101 to 104.)

176

A TEXT-BOOK OF BOTANY.

The drugs thus far studied may to some extent be grouped
according to the sublimable constituents which give characteristic
reactions. I. Thein- or caffeine-containing drugs, as coffee, tea,
cacao, and guarana. 2. Arbutin-containing drugs or those yielding
hydrochinon, as uva-ursi and other Ericaceae. 3. Drugs yielding
oxymethylanthraquinone and giving a distinct purple color with
solutions of the alkalies, as rhamnus purshianus, frangula, rheum,
senna, etc.

FIG. 103. Alkaloids of ipecac obtained by sublimation as follows: 0.050 Gm. of the
powdered drug is mixed with 2 drops of water on a glass. slide and heated; the third dis-
tillate at a temperature of 100° to 115° C. gives colorless or yellowish, highly refractive
globules (A) in which crystals of emetin separate. B , Short, rod-shaped crystals of the double
salts formed on the addition of gold chloride to the globules of the oily distillate. C, Oily
globules of the distillate uniting and in which, upon the addition of potassium bismuth
iodide, small spherites arise. D, Crystals of the alkaloids formed on treating small sections
of ipecac or o.ooi Gm. of the powder with an aqueous solution of picric acid acidified with
hydrochloric acid. E, Crystals formed at edge of cover glass. — After Tunmann in Gehe &
Co.'s Handelsbericht, 1912.

Cell-sap Colors. — The majority of the other color-substances
found in the higher plants besides the green and yellow principles
previously mentioned occur in solution in the cell-sap, and may
be in the nature of secondary substances derived from the plastid
pigments, or they may be produced directly by the protoplasm.
Upon making sections of the tissues containing cell-sap color-
substances, not infrequently strikingly contrasting colors are
observed in contiguous cells; as in the petals of the poppy and

CELL-CONTENTS AND FORMS OF CELLS. 177

petals of certain lilies, where we find some cells of a deep purple
color, others of a deep red, and still others of intermediate shades.
These substances are easily extracted with water or dilute alco-
hol and are all more or less affected by certain chemicals (many
of which occur naturally in the plant), such as citric acid, oxalic
acid, salts of calcium, iron, aluminum, etc.

FIG. 104. Microcrystals formed in Kava-kava, the root of Piper methysticum: A,
crystals of methysticin obtained on treatment of sections of the root or the powder with
alcohol, the crystals being long rods, of a light yellow color, attaining a length of 0.160 mm.
and becoming of a violet red on the addition of sulphuric acid. B, Crystals of methysti-
cinic acid obtained upon heating a small quantity of the powder with one or two drops
of a solution of potassium hydroxide, then adding dilute alcohol and allowing the slide to
stand for 24 hours. Crystals of methysticin can also be obtained upon sublimation, pro-
viding the powder has been acted on previously with dilute sulphuric acid, emulsin, or
saliva. — After Tunmann in Gehe & Co.'s Handelsbericht, 1912.

A number of plant pigments of this class are used as indi-
cators in volumetric chemical analysis, their use in this connection
being dependent upon their sensitiveness to acids and alkalies.
The fact that they respond to iron salts, — that is, give a blue or
green reaction with these salts, — would indicate that they are
associated with tannin or that they are tannin-like compounds, as
has been supposed by some writers, but they behave very differ-

12

178 A TEXT-BOOK OF BOTANY.

ently from tannin toward other reagents, such as organic acids,
alkalies, lime water, and solution of alum.

An examination of the color-substances of a large number of
plants shows that the flower color-substances are distributed in
all parts of the plant. For example, the flower color-substance of
the rose occurs in the leaves and prickles as well as in the petals.

The color-substance in the root of the radish closely corre-
sponds to that in the flowers, while the one in the grains of black
Mexican corn corresponds to that in corn silk.

The cell-sap color-substances are usually found in greatest
amount at the tips of the branches, this being well marked in the
foliage of the rose, and may be said to be rather characteristic
of spring foliage. Not infrequently in the purple beech the young
leaves will be of a distinct purplish-red color and almost entirely
free from chlorophyll, suggesting a correspondence in position
and color to a flower.

Color in Autumn Leaves. — The coloring matters in both
spring and autumn leaves closely resemble the cell-sap color-
substances of flowers, although it is the spring leaves which give
the most satisfactory results when examined. The fact that in
the autumn leaves there is little or none of the plastid pigment
present would point to the conclusion that the color-substances
occurring in these leaves are in the nature of by-products and of
no further use to the plant. Of course, in the case of autumn
leaves, we know that these products cannot be further utilized
by the plant, and for this reason we are justified in regarding
them as waste products.

So-called White Colors. — The so-called white colors in plants
do not properly belong to either class, but may be said to be
appearances due rather to the absence of color, and depending
upon the reflection of light from transparent cells separated by
relatively large intercellular spaces containing air. In other words,
the effect produced by these cells may be likened to that produced
by the globules in an emulsion. The white appearance is most
pronounced in the pith cells of certain stems, where on the death
of the cells the size of the intercellular spaces is increased and
the colorless bodies in the cells as well as the walls reflect the
light like snow crystals.

CELL-CONTENTS AND FORMS OF CELLS. 179

CHEMISTRY OF PLANT COLOR PRINCIPLES. — The substances
giving colors in plants may be divided into two classes: i. Sub-
stances having a specific color, as chlorophyll in leaves,- chromo-
phyll in flowers and fruits, and anthocyanin, the cell-sap color
in flowers. 2. Substances which, while they themselves are color-
less and known as leuco-compounds, yet form color derivatives.
Some of these are more or less readily oxidized, forming charac-
teristic color-substances, as brazilin. Again, some occur as gluco-
sides which through the action of ferments yield color-substances,
as quercitrin, which yields the yellow pigment quercetin. All of
the researches which have been made seem to indicate that the
color in plants is due to a basic substance or nucleus, and that
the variation in color is due to the nature and arrangement of
certain groups and side chains. For example, benzo-quinhydrone
is green in color, while thymo-quinhydrone is of a purplish color
(Pharm. Review, 1908, p. 330) . Again, the hydroxybenzoquinones
vary in color with the number of hydroxy groups, hydroxybenzo-
quinone being of a light yellow, di-hydroxybenzoquinone is of a
dark yellow, tri-hydroxybenzoquinone is of a black color, and
tetra-hydroxybenzoquinone is of a bluish-black color.

In the artificial dyes there are a number of so-called chromo-
phores or chromophorous groups (radicals) characteristic of the
various classes. In plant color-substances, on the other hand, we
find the carbonyl group (C = O), the imido group (NH), and
C = C group. The introduction of the chromophorous radical
gives a basic compound which is more or less colored and known
as a chromogen. The intensity of the color varies on the intro-
duction of certain salt-producing groups or auxochromes. In
the case of plant pigments, the most important of these is the
hydroxyl group, and, as we have just seen, the intensity of color
varies according to the number of these groups.

According to their constitution, plant color principles may be
arranged into six different classes: i. Phenol derivatives, includ-
ing oTcin, the coloring principle in many lichens, that forms color-
less prisms which become red ; and thymo-quinone found in
Monarda (Kremers, in Pharm. Rev., 1908, p. 329). 2. Naphtha-
lene derivatives, including juglon, which forms garnet-colored
needles. 3. Anthracene derivatives, including alizarin, the color-

180 A TEXT-BOOK OF BOTANY.

ing principle in madder root. 4. Pyrone derivatives, of which
there are several, as gentisein, maclurin, catechin, and rottlerin.
being xanthone derivatives ; quercetin, rhannetin, and fisetin, which
are flovone derivatives ; and hsematoxylin and brasilin, being chro-
mene derivatives. 5. Isoquinoline, of which berberine is an ex-
ample. 6. Benz-pyrrol derivatives ; in this group is indigotin or
indigo blue, the coloring principle in Indigofera tinctoria>.

ORIGIN AND FORMATION OF ANTHOCYANIN. — At the present
time it is very difficult to determine the nature of the chemical
processes which underlie the formation of anthocyanin, or the
pigment dissolved in the cell-sap and giving the blue, purplish, and
reddish color to flowers, fruits, etc. A great many observations
have been made on the distribution of anthocyanin, the nature
of the constituents with which it is associated in the plant cell,
and their relation to various metabolic processes. In order to
determine the Mendelian factors for color it is necessary that
we have a definite knowledge concerning the nature and formation
of this pigment. Of the numerous theories which have been
proposed concerning the formation of anthocyanin, that proposed
by Muriel Wheldale (Jour. Genetics, 1911, p. 134) seems the most
plausible and is as follows:

(1) The soluble pigments of flowering plants, collectively
termed anthocyanin, are oxidation products of colorless chromo-
gens of an aromatic nature, which are present in the living tissues
in combination with sugar as glucosides.

(2) The process of formation of the glucoside from chromo-
gen and sugar is of the nature of a reversible enzyme action :

Chromogen + sugar "^""^ glucoside + water.

(3) The chromogen can only be oxidized to anthocyanin after
liberation from the glucoside, and the process of oxidation is
carried out by one or more oxidizing enzymes :

Chromogen + oxygen = anthocyanin.

(4) From (2) and (3) we may deduce that the amount of free
chromogen, and hence the quantity of pigment formed at any
time in a tissue, is inversely proportional to the concentration
of the sugar and directly proportional to the concentration of
glucoside in that tissue.

(5) The local formation of anthocyanin, which is character-

CELL-CONTENTS AND FORMS OF CELLS. 181

istic of the normal plant, is due to local variation in concentration
of either the free sugars or the glucosides in the tissues in which
the pigment appears. The abnormal formation of pigment under
altered conditions is due to differences in the concentration of
these same substances due to changes in metabolism brought about
by these conditions.

(6) On the above hypothesis the formation of anthocyanin is
brought into line with that of other pigments produced after the
death of the plant, as, for example, indigo and the post-mortem or
respiration pigments, so termed by Palladin.

FUNCTION OF PLANT COLORS. — A great many theories have
been advanced as to the nature and uses of color-substances by
the plant. With the exception of chlorophyll present in the chloro-
plastid and its relation to photosynthetic processes little is known
concerning the other pigments. Without attempting to discuss the
various theories which have been proposed concerning their uses,
the following facts should be borne in mind :

1. The occurrence of chromoplastids in a reserve organ, as in
the tuberous root of carrot, and the similar occurrence of chromo-
plastids and of reserve starch in the petals of the buttercup, lead
to the inference that the petal of the buttercup, like the root of the
carrot, has the function of storing nutrient material. In each case
cells containing chromoplastids rich in nitrogenous substances are
associated with cells containing reserve materials.

2. The distribution of the so-called flower color-substances in
other parts of the plant than the flower shows them to be in the
nature of metabolic substances, and that the part which they play
in attracting insects to flowers is incidental rather than funda-
mental. (The fact that certain colored flowers as in spruce are
pollinated by the wind would tend to confirm this view.)

3. Unorganized or cell-sap color-substances are distributed
usually in largest amount at the termini of the branches, as in
flowers and terminal leaves, or in roots, or in both tops and roots.
Their occurrence in those portions of the plant which are young
and growing points to the conclusion that they are not to be disre-
garded in the study of metabolic processes. Goebel likewise
holds to this view. He says that it is " very probable that the

182 A TEXT-BOOK OF BOTANY.

feature of color which so often appears when the propagative
organs are being brought forth has some connection with definite
metabolic processes, although up till now we cannot recognize
what these are."

ARTIFICIAL COLORING OF FLOWERS. — Ever since the time of
Magnol (1709) there has been considerable interest in the subject
of coloring white flowers. A number of aniline dyes can be used,
but those belonging chiefly to the azo and rosaniline coloring
matters, especially the acid dyes or those used for dyeing wool,
give the best result. These dyes are readily soluble in water, and
the solutions are made up of a strength of I part of dye to 1,000
parts of water. The effects are best seen in white flowers and
are produced by allowing the flower-stalks to remain in the solu-
tions from one to two hours, when they are placed in water.
With some flowers, as the cultivated anemones, the effects are
noticeable in from ten to fifteen minutes. Some flowers will take
up the dyes better than others. White flowers may be changed
to yellow, orange, blue, green, purplish-red or magenta, crimson,
purple, salmon-pink or gray by the use of the following dyes:

1. Yellow flowers are produced by the use of the dye known
commercially as " Acid Yellow A. T.," which is chemically the
sodium salt of disulpho-diphenylazin-dioxytartaric acid.

2. Orange-colored flowers may be produced by the use of the
Jdye " Orange G. G.," which is the sodium salt of benzene-azo-/?-
'naphthol-disulphonic acid.

3. Blue flowers may be produced by the use of the dye
" Cyanol F. F.," which is the sodium salt of meta-oxy-diethyl-
diamido-phenyl-ditolyl-carbinol-disulphonic acid.

4. Green flowers may be produced by the use of equal parts
of the dyes " Acid Yellow A. T.," and " Cyanol F. F."

5. Purplish-red flowers are produced by the use of the dye
" Acid Magenta," which is the sodium salt of the trisulphonic
acid of rosaniline.

6. Crimson flowers may be produced by the use of equal parts
of the dyes " Acid Yellow A. T." and " Acid Magenta."

7. Purple flowers may be produced by the use of equal parts
of " Cyanol F. F." and " Acid Magenta."

CELL-CONTENTS AND FORMS OF CELLS. 183

8. Salmon-pink flowers may be produced by the use of the dye
" Brilliant Croceine M. O. O.," which is the sodium salt of ben-
zene-azo-benzene-azo-/?-naphthol-disulphonic acid.

9. Gray flowers may be produced by the use of the dye " Naph-
thol Black B.," which is the sodium salt of disulpho-/?-naphtha-
lene-azo- «-naphthalene-azo-/?-naphthol-disulphonic acid.

Calcium oxalate is found in many of the higher plants, and
in the algae and fungi as well ; while in the mosses, ferns, grasses,
and sedges it is seldom found. It occurs in plants in crystals of
either the monoclinic or tetragonal system. The crystals dissolve
in any of the mineral acids without effervescence, and their identity
is usually confirmed by the use of dilute hydrochloric acid. The
crystals of the monoclinic system are rather widely distributed,
while those of the tetragonal system are less frequent in their
occurrence.

The crystals belonging to the monoclinic system (Fig. 105)
may be subdivided according to their prevalent forms into a num-
ber of sub-groups.

I. SOLITARY CRYSTALS. — These are usually in the form of
rhombohedra, sometimes in twin crystals of variable size (Fig.
108). They are very widely distributed, occurring in a number of
modifications in the same plant, and are often very characteristic in
the identification of economic products. The crystals of this group
are sometimes mistaken for silica, owing to the fact that in some
instances the lumen of the cell is completely filled by the crystal,
and, the inner wall having the contour of the crystal, it is impossible
to determine whether the crystal is affected by the use of hydro-
chloric acid. It should be stated in this connection that silica
never occurs as a cell-content in sharp, angular crystals, but either
in more or less ellipsoidal or irregular hollow masses, or in some-
what solid, irregularly branching forms (Fig. 109).

II. COLUMNAR CRYSTALS or " styloids," being elongated prisms
of the monoclinic system (Fig. 107, C), and when typical recall
ihe crystals of gypsum. They also occur in twin-forms, some-
limes replacing raphides, and occasionally show a number of
transition forms.

Solitary crystals in the form of rhombohedra or styloids occur
in a number of drugs, as follows : Acer spicatum, calumba, carda-

184

A TEXT-BOOK OF BOTANY.

PIG. 105. Monoclinic crystals of calcium oxalate: A, a to f, crystals from the paren-
chyma of the bark of the horse-chestnut (ALsculus Hippocastanum); B, a to c, from the pith
of Periploca grceca; C, a to e, from the parenchyma in the region of the fibrovascular bundles
in Musa sinensis; D. a to c, from the petioles of the pinnate leaves of Cycas revoluta; E, a to
c, crystals from the bark of the guaiac tree; F, a single crystal from Citrus aurantium; G,
a to c, rectangular crystals from a Brazilian bignonia. — After Dippel in "Das Mikroskop."

CELL-CONTENTS AND FORMS OF CELLS. 185

momum, coca, eucalyptus, frangula, gelsemium, granatum, hama-
melis, hyoscyamus, Jamaica quassia, krameria, pimenta, Prunus
serotina, quercus, quillaja, rhamnus purshianus, senna, uva-ursi,
vanilla, viburnum prunifolium, and xanthoxylum.

III. ROSETTE AGGREGATES of calcium oxalate consist of numer-
ous small prisms and pyramids, or hemihedral crystals more or
less regularly arranged around a central axis, and have the appear-

FIG. 1 06. Orthorhombic crystals of calcium oxalate: A, a to f, crystals from the leaves
of the onion (Allium Cepa)\ B, a to g, crystals from the stem of Tradescantiaviridis. — After
Dippel in "Das Mikroskop."

ance of a rosette or star (Fig. 107, A). The development of
these aggregates may be readily observed in the 'stem of Datura
Stramonium. Crystals of this class are more widely distributed
than any of the others, and are characteristic of a number of drugs.
Clustered crystals in the form of rosette aggregates occur in
numerous drugs, as follows: Althaea, anisum, buchu, calendula,
cannabis indica, carum, caryophyllus, castanea, chimaphila, conium,
coriandrum, cusso, eriodictyon, euonymus, fceniculum, frangula,
galla, geranium, gossypii cortex, granatum, humulus, jalapa, pilo-

i86

A TEXT-BOOK OF BOTANY.

carpus, pimenta, rheum, rumex, senna, stillingia, stramonii folia,
viburnum opulus, and viburnum prunifolium.

IV. RAPHIDES are groups of needle-shaped crystals, especially
prevalent in Monocotyledons (Fig. 107, B). They have been mis-

FIG. 107. Forms of calcium oxalate crystals: A, transverse section of rheum show-
ing rosette aggregates of calcium oxalate in three of the cells and starch grains in some of
the others; B, longitudinal section of scilla showing raphides; C, longitudinal section of
quillaja showing large monoclinic prisms of calcium oxalate and also some starch grains;
D, transverse section of belladonna root showing one cell filled with sphenoidal micro-crys-
tals, the remaining cells containing starch.

taken by several observers for calcium phosphate. Calcium phos-
phate, however, occurs in plants either in solution or in com-
bination with protein substance. The cells containing raphides
are long, thin-walled and contain, sooner or later, a mucilage,

CELL-CONTENTS AND FORMS OF CELLS. 187

which arises from the cell-sap, is stained by corallin, and behaves
with reagents much like cherry-gum. The cells are either isolated
or occur in groups placed end to end, as in Veratrum viride.

Raphides are found in relatively few drugs, as follows :
Cinnamomum, convallaria, cypripedium, ipecacuanha, phytolacca,
sarsaparilla, scilla, vanilla, and veratrum viride.

V. CRYSTAL FIBERS. — In quite a number of drugs a single
monoclinic prism or a rosette aggregate occurs in each of the
parenchyma cells adjoining the sclerenchymatous fibers, and to
this single longitudinal row of superimposed cells the name crystal

FIG. 1 08. A, transverse section of hyoscyamus leaf showing monoclinic prisms of
calcium oxalate, also a twin-crystal; B, longitudinal section of glycyrrhiza showing a
crystal fiber, i.e., a row of superimposed cells, each containing a polygonal monoclinic
prism of calcium oxalate, the crystal filling the cell. Adjoining the crystal fiber is a group
of bast fibers on one side and some cells containing starch on the other.

fiber has been applied (Fig. 108, B). Crystal fibers are typical
of the following drugs: Aspidosperma, frangula, glycyrrhiza,
hsematoxylon, hamamelis, Prunus serotina, quercus alba, quil-
laja, rhamnus purshianus, and uva-ursi.

VI. MICRO-CRYSTALS are exceedingly small (about 0.2 to lo/*
in diameter), apparently deltoid or arrow-shaped, and so numerous
as to entirely fill the parenchyma cells in which they occur, giving
the cells a grayish-black appearance which readily distinguishes
them from other plant cells (Fig. 107, D). It has been sup-
posed that they are tetrahedrons, but they are probably sphenoids

i88

A TEXT-BOOK OF BOTANY.

in the monoclinic system, inasmuch as monoclinic prisms occur in
neighboring cells in the same plant or drug, as in stramonium,
quassia, etc. Because they are so small and in many instances
not clearly defined they have been termed by the Germans " crystal-

FIG. 109. Various forms of Silica found in plants. Long rods and spindle-shaped
masses (A) and star-shaped fragments (B) found respectively in the thalloid structure
made up of roots and shoots and in the leaves of Tristicha hypnoides, a small, moss-like
plant (Podostemaceae) growing on rocks, etc., in running water, especially in waterfalls.
C, a longitudinal section of the petiole of Caryota urens, a palm of Eastern Asia, showing
grape-like clusters of silica completely filling the cells. D, hat-shaped fragments of silica
occurring on the edge of the leaves of Cusparia macrophylla. a rutaceous tree growing near
Rio Janeiro; in a, b, c, side views of the masses, whereas in d the surface view shows a struc-
ture resembling that of sphero-crystals, E and F, siliceous fragments from the leaves of an
orchid, Oncidium leucochilum, growing in Guatemala; in E is shown a base fiber with siliceous
masses somewhat resembling the crystal-fibers of calcium oxalate, and in F the isolated
siliceous masses are seen. — A and B, after Cario; C and D, after Rosanoff; E and F, after
Pfitzer. — From Dippel in "Das Mikroskop."

sand" (Kristallsand). The typical tetrahedral form was recog-
nized by the French and termed " sable tetraedrique."

Sphenoidal micro-crystals are found in the following drugs :
Belladonnae folia, belladonnse radix, cinchona, dulcamara, phyto-
lacca, quassia, Solanum carolinense, and tabacum.

CELL-CONTENTS AND FORMS OF CELLS. 189

VII. MEMBRANE CRYSTALS. — There are several forms of
crystals which may be included in this group. The so-called
Rosanoff crystals consist of rosette aggregates attached to inward-
protruding walls of the plant cell. These, however, do not concern
us so much as the large monoclinic crystals which have a mem-
brane surrounding them. The crystal first appears in the cell-sap,
and then numerous oil globules appear in the protoplasm around
it; later some of the walls of the cell thicken and grow around
the crystal, which they finally completely envelop, as in Moracese.

Crystals of the orthorhombic system may occur either as soli-
tary crystals or rosette aggregates, or in the form of acicular
crystals and probably micro-crystals, being usually much smaller
than the single crystals of the monoclinic system.

Solereder, in his work on " Systematic Anatomy of the Dicoty-
ledons," states that the systematic value of the study of the forms of
crystals varies considerably. While in some instances a certain
form of crystal is characteristic of an entire order, yet in other
cases it serves to distinguish only genera or species. In practical
work in the identification of economic products the study of the
forms of crystals is very important. A few instances may be
mentioned. In Jamaica quassia calcium oxalate occurs in the
form of 4- to 6-sided rhombohedral crystals, whereas in Surinam
quassia the crystals are few or entirely wanting. In Levant
scammony root occur numerous monoclinic prisms of calcium oxa-l
late, whereas in the Mexican root the crystals are chiefly in the
form of rosette aggregates. In the bark of Viburnum Opulus the
calcium oxalate occurs almost entirely in the form of rosette aggre-
gates, whereas in the bark of Acer spicatum solitary rhombo-
hedral crystals are prevalent. In the identification of many
drugs the presence or absence of calcium oxalate crystals and
the study of the prevalent forms is very important (Fig. no).

Owing to the importance of the study of calcium oxalate an
enumeration of the families in which calcium oxalate occurs is
given.

I. Crystals of calcium oxalate, either in the form of solitary
rhombohedra or clustered aggregates, are found in the following*
families: Aceracese, Ampelidacese (also raphides), Anacardiaceae,
Apocynacese, Araliacese, Asclepiadaceae, Berberidaceae, Bignonia-

190

A TEXT-BOOK OF BOTANY.

A B

FIG. no. A few illustrations showing the practical value of the study of calcium
oxalate: A, digitalis, without any calcium oxalate; B, hyoscyamus in which monoclinic
prisms predominate; C, belladonna, characterized chiefly by sphenoidal micro-crystals as
well as occasional prisms; D, stramonium, having rosette aggregates in addition to prisms
which are found in the petioles and stems and sphenoidal micro-crystals, which are abundant
in the root. — a, upper epidermis; b, lower epidermis; c, non-glandular hairs (which in stra-
monium art tubercutete) ; d, glandular hairs; e, calcium oxalate crystals; f, fragments of
xylem showing tracheae with bordered pores (s), reticulate markings (r), simple pores (p),
spiral thickening (1), and wood fibers (w); g, bast fibers, which, together with wood fibers,
are wanting in digitalis.

CELL-CONTENTS AND FORMS OF CELLS. 191

ceae (also in the form of octahedra and small acicular crystals),
Bixaceae, Bruniaceae, Burseraceae, Buxaceae (also styloids and
micro-crystals), Cactaceae, Canellaceae, Capparidaceae, Caprifolia-
ceae, Caryophyllaceae, Casuarinaceae, Celastraceae, Combretaceae,
Convolvulaceae (also small acicular crystals), Cornaceae (also
micro-crystals), Ebenaceae, Ericaceae, Euphorbiaceae, Fagaceae,
Geraniaceae (also raphides), Gutti ferae, Hamamelidaceae, Hippo-
castanaceae, Hypericaceae, Juglandaceae, Lecythidaceae, Linaceae,
Loganiaceae, Loranthaceae, Lythraceae; Magnoliaceae, Malpighia-
ceae, Malvaceae, Meliaceae, Menispermaceae (also small acicular
crystals), Moraceae, Myricaceae, Myrsinaceae, Myrtaceae, Oleaceae,
Passifloraceae, Pittosporaceae (also columnar crystals), Platana-
ceae, Plumbaginaceae, Podostemaceae, Polygalaceae, Polygonaceae,
Portulacaceae (also micro-crystals), Rhamnaceae, Rhizophoraceae,
Rosaceae, Rubiaceae (also raphides, micro-crystals, rhombohedra,
and small acicular crystals), Rutaceae (also styloids and raphides),
Salicaceae, Santalaceae, Sapindaceae, Sapotaceae (also micro-crys-
tals), Saxifragaceae, Simarubaceae, Solanaceae (also micro-crys-
tals), Staphyleaceae, Sterculiaceae, Theaceae (also^ raphides and
styloids), Thymelaeaceae (also micro-crystals), Tiliaceae, Ulmaceae,
Urnbelliferae, Urticaceae, Vaccinaceae, Verbenaceae (also small
prisms and acicular crystals), Violaceae, and Zygophyllaceae.

Solitary rhombohedra are found in a relatively few families
and are characteristic of the following : Connaraceae, Crassulaceae,
Cucurbitaceae, and Leguminosae.

II. Crystals in the orthorhombic system occurring in the form
of small octahedra or prisms, as twin-crystals, and in the form of
short rods or needles are found in the following families : Acera-
ceae, Apocynaceae, Araliaceae, Aristolochiaceae, Begoniaceae, Big-
noniaceae, Boraginaceae, Cactaceae, Caesalpinaceae, Calycanthaceae,
Campanulaceae, Canellaceae, Capparidaceae, Chenipodiaceae, Com-
positae, Convolvulaceae, Gentianaceae, Gesneraceae, Guttiferae, Lau-'
raceae, Loganiaceae, Magnoliaceae, Melastomaceae, Menispermaceae,
Moraceae, Myristicaceae, Monimiaceae, Oleaceae, Papilionaceae,
Phytolaccaceae, Piperaceae, Polemoniaceae, Ranunculaceae, Rubia-
ceae, Saxifragaceae, Scrophulariaceae, Simarubaceae, Solanaceae,
Sterculiaceae, Styracaceae, and Zygophyllaceae.

192 A TEXT-BOOK OF BOTANY.

III. Rosette aggregates or clustered crystals sometimes accom-
panying other forms are found in the following families : Acantha-
ceae, Begoniaceae, Boraginaceae, Calyceraceas, Campanulaceae, Can-
dolleaceae, Chenopodiaceae, Chloranthaceae, Elatinaceae, Empetra-
ceae, Gentianaceae, Gesneraceae, Hydrophyllaceae, Labiatae, Loasa-
ceae, Magnoliaceae, Melastomaceae, Melianthaceae, Myristicaceae,
Nepenthaceae, Nymphaeaceae, Onagraceae, Papaveraceae, Phytolac-
caceae, Piperaceae, Polemoniaceae, Ranunculaceae, Sarraceniaceae,
and Turneraceae.

IV. Sphaerites (sphere-crystals), or rosette aggregates com-
posed of very small needles, have been observed in certain plants of
the following families: Aceraceae, Asclepiadaceae, Berberidacese,
Cactaceae, Combretaceae, Crassulaceae, Empetraceae, Euphorbiaceae,
Geraniaceae, Melastomaceae, Papilionaceae, Phytolaccaceae, Rosa-
ceae, and Solanaceae.

V. Raphides are sometimes associated with other forms of
crystals, as micro-crystals, rosette aggregates, rhombohedra, and
styloids. They are widely distributed among the Monocotyledons
and occur in the following Dicotyledons : Geraniaceae, Gesneraceae,
Melianthaceae, Phytolaccaceae, Rubiaceae, Rutaceae, Saxifragaceae,
Theaceae, Urticaceae, and Zygophyllaceae.

PLANT PROTEINS.

T^e proteins are nitrogenous compounds, most of which con-
tain sulphur and some of which contain phosphorus. Their con-
stitution or the molecular structure of their molecules has not
been determined, but they are very large, and are built up of amino-
acids, the simplest of which is glycocoll (amino-acetic acid).

Apart from the protoplasm found in living cells, the propor-
tion of proteins in plants is relatively small, except in seeds, where
they serve as nutriment during the germinating period, being made
available by the action of proteolytic enzymes. Most of the plant
proteins are GLOBULINS, and collectively have been termed phyto-
globulins. (i) The globulins are insoluble in pure water and in
dilute acids, but are soluble in dilute solutions of sodium chloride
(i to 20 per cent.), ammonium chloride, sodium sulphate and
dilute solution of potassium hydrate, from which solutions they
may be precipitated by dilution, dialysis, or acidification with CO2

CELL-CONTENTS AND FORMS OF CELLS. 193

or dilute acids, or by " salting out " by the use of strong or satu-
rated solutions of ammonium sulphate, magnesium sulphate, or
sodium chloride. (2) The proteins which contain phosphorus are
sometimes called phytovitellins, as legumin in peas, which contain
0.35 per cent, of phosphorus. A third class of plant proteins,
which are alcohol-soluble, are found in cereals, as the gliadin
of wheat and rye and the zein of maize. The cohesive and dough-
ing properties of wheat flour are attributed to the association of
gliadin and another protein called glutenin.

Some of the plant proteins occur naturally in the crystalline
form, either free in the cytoplasm, as in the potato tuber (Fig. in,
A), or as components of aleurone grains, as in the seeds of
Ricinus communif and Brazil nuts (Fig. HI, B and D). Phyto-
globulins in the form of crystals and spheroids have been obtained
from extracts of flax-seed, hemp-seed, Brazil-nut, castor-oil seeds
and others. Protein crystals are, according to Wichmann, iso-
morphic, and probably belong to the hexagonal system (Fig. 112).

Aleurone grains are made up of phyto-globulins (formerly
called crystalloids), globoids and a ground mass, the whole being
enclosed by a membrane-like material. They may be studied by
taking advantage of the difference in solubility of the substances
composing them. The membrane, or lining of the protoplasm,
while soluble in water, remains intact with sections examined in
any of the fixed oils, as cotton-seed oil. Usually seeds which
contain aleurone are rich in fixed oils, and if this oil is first removed
by placing fresh sections in alcohol, or alcohol and ether, the
subsequent study is facilitated. If the sections thus treated are
mounted in water, the membrane gradually dissolves, leaving
the globulins, globoids, and calcium oxalate. On adding a o.i
to i per cent, solution of either sodium or potassium hydrate, the
globulins dissolve, the globoids and calcium oxalate crystals re-
maining unaffected. The globoids may be dissolved by the use
of a i per cent, acetic acid solution, or concentrated solutions of
ammonium sulphate or monopotassium phosphate. The calcium
oxalate remaining may then be treated with hydrochloric acid in
the usual way.

CLASSIFICATION OF PROTEINS. — A committee on protein nomen-
clature of the American Society of Biological Chemists proposed
13

194

A TEXT-BOOK OF BOTANY.

a classification of Proteins based chiefly on their solubility under
different conditions. There are some eighteen different classes
recognized, and these are brought under three principal groups:
(i) Simple Proteins, as albumins, globulins, glutelins, prolamins,
etc. (2) Conjugated Proteins, or complex substances, as nucleo-

FIG. in. Phyto-globulins: A, cell of tuber of white potato (Solanum tuberosum)
showing protein cyrstals (k), starch grains (st), nucleus (n); B, aleurone grains of the
seed of the castor-oil plant (Ricinus communis); C. aleurone grains of fruit of fennel (Fcenic-
ulunt vulgare) containing large calcium oxalate crystals (Ca) which are strongly polarizing,
as shown in the isolated grains; D, aleurone grains of Brazil-nut (Bertholletia excelsa);
g, globoids; k, protein crystals.

proteins, which are compounds containing both nucleic acid and
protein. (3) Derived Proteins, or compounds resulting from the
action of enzymes or acids upon proteins.

I. Most of the investigations up until now have been con-
ducted on the Globulins, which are distinguished by being insoluble
in water but soluble in saline solutions. A number of them readily
crystallize, and these can be generally obtained by diluting their

CELL-CONTENTS AND FORMS OF CELLS. 195

sodium chloride solutions with water heated from 50° to 60° until
a slight turbidity forms. Warm the diluted solution until the tur-
bidity disappears and then allow it to cool slowly, when well-
defined crystals of the protein separate (Fig. 112). Crystals of
the globulin (so-called excelsin) of Brazil-nut were obtained by
Osborne by simply dialyzing the faintly acid saline solution in
running water. Many of the globulins have received distinctive
names, as Amandin, found in the almond, peach, plum, and apri-
cot ; Avenalin, found in oats ; Castanin, found in European chest-
nut; Conglutin, found in lupines; Corylin, found in hazel-nut;
Edestin, found in hemp-seed ; Excelsin, found in Brazil-nut ;
Glycinin, found in soy-bean; Juglansin, found in European wal-
nut, American black walnut, and butter-nut; Legumin, found in
peas and lentils ; Maysin, found in Indian corn or maize ; Phaseolin,
found in kidney and lima beans; Tuberin, found in the potato;
Vicilin, found in peas, horse-bean, and lentils ; and Vignin, found
in cow-pea. Globulins have also been isolated from the seeds of
other plants, but to these distinctive names have not yet been
given. Among these may be mentioned barley, cocoanut, castor-
bean, cotton-seed, flaxseed, mustard-seed, peanut, radish-seed,
rape-seed, rye, sesame-seed, sunflower-seed, and squash-seed.

II. ALBUMINS are distinguished from globulins by the fact
that they coagulate on the application of heat ; they are also solu-
ble in water, showing neutral or but a slightly acid reaction. Most
seeds and probably most plant juices yield proteins which are as
well entitled to be placed in the group of albumins as any of
those of animal origin. The best characterized vegetable albumins
are Legumelin, found in lentils, cow-peas, peas, and soy-beans ;
Leucosin, found in barley, rye, and wheat; Phaselin, found in
kidney-bean; and Ricin, found in castor-bean.

III. Another well-defined class of Proteins are known as
GLUTELINS, which are characterized by being insoluble in neutral
aqueous solutions, saline solutions, and alcohol. The glutenin of
wheat is the best representative of this group.

IV. The alcohol-soluble proteins, known as Prolamins, have
been found in corn, oats, sorghum, and wheat. It has recently been
proposed to bring this group of proteins in a group by themselves
and call them " gliadins," but as this name has been used to

196 A TEXT-BOOK OF BOTANY.

designate a definite protein obtained from wheat/a more distinctive
name has been proposed by Osborne, who calls this group " pro-
lamins," because all its members which have thus far been hydrol-
yzed yield a relatively large quantity of both proline and amide
nitrogen. The prolamins are characterized by their solubility in
alcohol from 70 to 90 per cent. They are nearly or wholly insoluble
in water, but their salts are freely soluble in solutions of acids or
alkalies. (See " The Vegetable Proteins/' by Thomas B.
Osborne.)

GLUTEN is a mixture of proteins occurring in wheat. It con-
sists of about 4 per cent, of gliadin (prolamin) and 4 per cent, of
glutenin (glutelin). On an average 100 pounds of flour will yield
8 pounds of gluten. The " hard " wheats contain more gluten than
the " soft " varieties. The gluten of wheat is said to possess a
higher dietetic value than the gluten of corn or rye. Crude gluten
may be prepared by making a dough with 30 Gm. of flour and
about 15 c.c. of water. This is allowed to stand for an hour
and the starch washed out by kneading it between the fingers under
a gentle stream of tap water. The resultant product is of a
grayish color, sticky, tough, and elastic, and when pure is capable
of being drawn out into long bands or shreds. The strength of a
flour, — i.e., its capacity for making a porous and spongy loaf, — de-
pends mainly on the quality and quantity of gluten it contains.
In the preparation of ordinary flour much of the layer containing
gluten is separated with the coats of the grain in the course of
bolting. Graham flour, on the other hand, being unbolted, has
practically the same constituents as the wheat grain itself. The
name " gluten flour " is applied to one in which the greater part
of the starch is removed. Gluten flours are used by diabetic
patients and have a high nutritive value when scientifically pre-
pared.

TOXALBUMINS OR Toxic PROTEINS. — Proteins which are ex-
ceedingly toxic have been isolated, from several plants. That
the protein substances possess poisonous properties has sometimes
teen questioned, but there seems to be no doubt but that true
toxalbumins occur not only in seeds, but in other parts of the
plant. The following of these principles have been rather care-
fully studied: Ricin, found in the seeds of Ricinus communis;

CELL-CONTENTS AND FORMS OF CELLS. 197

FIG. 112. Phyto-globulins (crystaloids) from several sources: A, a, b, from the white
potato; B, a to f, from the seeds of castor oil plant (Ricinus communis); in b and b are shown
different views of the same crystal; C, a to f, from the seeds of the Brazil nut (Bertholletia
excelsd). — After Dippel in "Das Mikroskop."

198 A TEXT-BOOK OF BOTANY.

Abrin, occurring in the seeds of Abrus precatorius; Curcin, in the
seeds of Jatropha Curcas; Crotin, in the seeds of Croton Eluteria;
and Robin, in the bark of Robinia Pseud-acacia. The pollen
of rye is also said to contain a toxalbumin, which, when adminis-
tered in extremely small doses, accentuates the symptoms of hay
fever in patients afflicted with this disease. Under the name of
" Vegetable Agglutinins " have been brought those protein sub-
stances which when added to a suspension of blood-corpuscles rap-
idly cause them to agglutinate. Those substances that possess
the same properties but are not poisonous are known as
*; 'Phasins." (Consult "The Vegetable Proteins," by Osborne;
and." Beitrage zur Kenntnis der vegetabilischen Hamagglutinine,"
by R. Robert.)

ORIGIN AND FORMATION OF PLANT PROTEINS. — It has been
shown that carbohydrates originate in chloroplastids and are
formed under the influence of sunlight from two simple substances,
viz., carbon dioxide and water. Protein substances, on the other
hand, are not formed in any definite organ, but arise in the proto-
plasmic contents of the cell. This function is not limited to the
protoplasm of green plants, as fungi also possess this property.
Furthermore, proteins may be formed in organs growing in the
dark as well as those exposed to the light. Proteins arise through
the interaction of nitrates, sulphates, and compounds of ammonia
with either formaldehyde or some simple carbohydrate. It is
supposed that the nitrates and sulphates are decomposed by plant
acids, furnishing the necessary nitrogen and sulphur. Treub,
by reason of his studies on Pangium edule, has advanced the theory
that in the construction of protein compounds the nitrogen is
supplied by hydrocyanic acid. Apart from the facts just men-
tioned, all theories with regard to the formation of proteins are
mere speculations.

We are indebted to Emil Fischer and his students ("Unter-
suchungen iiber Aminosauren Polypeptide und Proteine," Berlin,
1906) for much information concerning the structure of proteins.
They have prepared synthetically several protein-like substances,
although no natural occurring protein has as yet been obtained.
From these studies it has been shown that proteins belong to a

CELL-CONTENTS AND FORMS OF CELLS. 199

class of chemical substances designated as " polypeptides " which
are formed by the condensation of several amino acids.

THE PERCENTAGE OF PROTEIN IN PLANTS. — The amount of
protein in plants varies considerably. It is found in greatest
amounts in seedsx especially in the seeds of the Leguminosse and
the grains of cereals. It is also found in surprisingly large quanti-
ties in a number of the vegetables. Were it not for the fact that the
fungi contain large quantities of water, they would be considered
the most nutritious of all vegetable foods, as they contain in dry
substances over 50 per cent, of protein. As the fresh mushrooms,
however, contain nearly 90 per cent, of water, this brings the pro-
tein content to but about 5 per cent. The percentage of protein
in dried material from a number of sources may be of interest, as
follows:

Grains or Cereals. — Barley, 7.64 to 17.90; buckwheat, 9.75 to
17.25; corn, 6.41 to 17.02; oats, 8.35 to 21.88; rye, 8.39 to 17.38;
rice, 6.49 to 12.81 ; and wheat, 8.30 to 27.88.

Leguminous Seeds. — Kidney beans, 22.53 to 36.46; lentils,
14.58 to 34.34; Hnia beans, 15.94 to 25.63; Lupinus luteus, 15.62
to 61.27; peanut, 25.39 to 33.73; peas, 21.59 to 32-94 ; soja beans,
24.38 to 49.10; string beans, 13.06 to 20.19; and Vicia faba, 21.00
to 36.10.

Miscellaneous Seeds. — Beechnut, about 25 ; cacao, 7.32 to
15.94; cocoanut, 7.75 to 10.90; chestnut, 5.15 to 15.75; hazel-nut,
16.23 to 21.22; flaxseed, 18.49 to 33.80; mustard, 15.50 to 39.66;
coffee, 17.11 to 25.09; rape-seed, 15.18 to 28.13; ricinus, 16.35 to
22.28; sunflower-seed, 5.67 to 33.89 ; sweet almond, 17.50 to 26.62.

Common Vegetables. — Asparagus, 15.12 to 33.52; sugar beets,
3.11 to 23.02; garden beets, 4.19 to 29.27; carrots, 3.79 to 16.64;
cauliflower, 17.23 to 37.75 ; celery, 8.44 to 25.19 ; cucumber, 21.38 to
26.06; garlic, 1.17 to 13.50; parsnips, 6.38 to 13.50; potatoes, 2.21
to 17.59; sweet potatoes, 1.70 to 19.61; radish, 13.00 to 22.13;
spinach, 27.50 to 45.33; and turnips, 4.01 to 21.00.

Fruits. — Apples, 0.22 to 1.32; apricots, 0.13 to 1.79; bananas,
3.37 to 7.75; cherries, 0.97 to 4.75; cucumber, 21.38 to 26.06;
currants, o.n to 1.44; figs, 0.90 to 2.58; gooseberries, .21 to .94;
grapes, 0.22 to 1.20; lemons, 0.49 to 2.90; musk melon, 4.69 to
22.23; oranges, 4.83 to 2.24; peaches, 0.23 to 1.67; pears, 0.19 to

200 A TEXT-BOOK OF BOTANY.

0.56; plums, 0.27 to 0.99; prunes, 0.59 to 0.69; pumpkin, 30.31 to
36.25; raspberries, 0.18 to 1.47; strawberries, 0.35 to 1.05.

Spices. — Anise, 16.31 to 18.15; capsicum, 11.20 to 16.81 ;
cardamom, 5.50 to 14.77; caraway, 19.43 to 20.25; cloves, 4.73 to
7.06; cinnamon, i.oi to 8.00; coriander, 10.94 to 12.03; curcuma,
9.18 to 12.56; dill, 6.75 to 21.56; fennel, 16.28 to 17.19; ginger,
3.27 to 10.83 ; mace, 4.55 to 7.80; mustard, 15.50 to 39.66; nutmeg,
5.16 to 7.12; pepper, 15.18; paprika, 10.9 to 27.16.

Miscellaneous. — Agaricus campestris, 20.63 to 62.94; sea-
weeds, 5.56 to 39.25.

CALCIUM CARBONATE occurs occasionally in the form of a cell-
content, being present in tracheae or vessels and tracheids of the
heart wood, as well as in the medullary rays and pith cells of
certain plants. In this form it is rather characteristic of one or
more genera in the following families : Aceraceae, Anonaceae,
Cornaceae, Cupuliferae, Rosaceae, Salicaceae, Sapotaceae, Urti-
caceae, and Zygophyllaceae. When present it almost completely
fills the cells, and may be overlooked or referred to as resin unless
its identity is proved by the use of certain reagents. Like the
other carbonates, it dissolves with effervescence on the addition
of hydrochloric acid, nitric acid, acetic acid, etc., and in this way
may be detected.

Calcium carbonate is present in special structures known as
Cystoliths. The latter are protuberances of the cell wall into the
cell, and consist of a stalk and a body (Fig. 113). The stalk
consists of a simple core of cellulose on which more or less silica
is deposited. The upper or body portion consists of a more or
less irregular spherical or ellipsoidal deposit of calcium carbonate.
These are found in the parenchyma cells in roots and barks and the
subepidermal cells of leaves. They are also found in epidermal
cells, as in the short hairs of Cannabis sativa. Cystoliths occur
in certain genera of the Acanthaceae, Borraginaceae, Cucurbi-
taceae, Gesneraceae, Oleaceae, Ulmaceae, Moraceae, and Urticaceae.

Cystoliths occur in a number of modifications, and, while they
are usually simple, yet in some of the Acanthaceae and Urticaceae
branched cystoliths occur. In some of the genera of the Cucur-
bitaceae 2- to 4-adjoning cells may have cystoliths, and hence are
known as " double cystoliths." The cystoliths found in hairs, as

CELL-CONTENTS AND FORMS OF CELLS. 201

in Cannabis sativa, do not usually have a stalk, and are known
as " hair cystoliths." The latter are, furthermore, variously modi-
fied, and may have incrustations of either calcium carbonate or
silica or a mixture of both of these substances. In the Begoniaceae
occurs a certain form of structure resembling a cystolith, but it is
uncalcified, and consists of a mucilaginous substance which is

r,

f

FIG. 113. Cystolith. A cross section of a portion of the leaf of Ficus elastica showing
cells of the upper epidermis (e), cells of the hypodermal layer (h), among which is a large
cell containing a cystolith (c); palisade cells (ch). — After Sachs.

sometimes more or less impregnated with resin. These are known
as " cystotyles." The protuberances found on the walls of
certain epidermal cells and in the subsidiary cells of hairs may
be either calcified or silicified, and occur in the families containing
true cystoliths and also some genera of the following: Com-
positae, Campanulaceae, Oleaceae, Leguminosae, Hydrophyllaceae,

202 A TEXT-BOOK OF BOTANY.

Scrophulariaceae, Polemoniaceae, Verbenaceae, Euphorbiaceae, and
Urticaceae.

SILICA is seldom found as a cell-content, and when present
never occurs as a crystalline deposit, being usually in the form of
amorphous masses, termed "silica-bodies" (Fig. 109). The
latter arise either in the cell-sap or the silica is deposited on the
cell-wall, ultimately filling the lumen of the cell. In the palms the
silica-bodies resemble stalkless cystoliths (Fig. 109, C). They may
also occur in the form of long rods, being more or less fusi-
form or rectangular, or in the form of discs showing a more or less
sphero-crystalline structure, or in other special forms (Fig. 109).
Silica-bodies have been found in the Palmae, Orchidaceae, Podoste-
maceae, and Rutacese. Silica is insoluble in any of the ordinary
solvents, being dissolved only by hydrofluoric acid. On incinerating
the tissues it is not destroyed. The presence of silica may be deter-
mined readily upon heating sections with sulphuric acid or any
reagent that destroys organic matter.

Silica usually occurs as an incrustation in the cell-wall, being
found in epidermal cells, spinose hairs, and even the palisade and
mesophyll cells of quite a number of plants. Siliceous walls are
rather characteristic of the genera of the following families :
Acanthaceae, Aristolochiaceae, Bignoniaceae, Borraginaceae,
Burseraceae, Calycanthaceae, Campanulaceae, Chloranthaceae,
Combretaceae, Compositae, Cucurbitaceae, Dilleniaceae, Euphor-
biaceae, Gesneraceae, Goodeniaceae, Hydrophyllaceae, Leguminosae,
Loranthaceae, Magnoliaceae, Melastomaceae, Menispermaceae,
Oleaceae, Piperaceae, Proteaceae, Rosaceae, Rubiaceae, Santalaceae,
Saxifragaceae, Urticaceae, and Verbenaceae.

TANNINS AND TANNIDES. — There is a group of water-soluble
principles that occur in the cell-sap, especially of parenchyma
cells, of a large number of plants. They are derivatives of phenol
and phenol acids, and give either dark blue or green precipitates
with solutions of ferric chloride. They were formerly designated
as tannins and distinguished according to the plants from which
they were obtained ; thus we had chestnut tannin, oak tannin, etc.
Recent studies on the constitution of these substances show that
there are two principal groups of tannins, ( I ) being in the nature
of glucosides and (2) the other not yielding any dextrose on

CELL-CONTENTS AND FORMS OF CELLS. 203

hydrolysis with acids. Both of these groups may be subdivided
into two classes, namely, (A) those which probably are deriva-
tives of protocatechuic acid and (B) those which are derivatives
of gallic acid. A class name has been given to include these
subgroups, namely, " tannides " or " tannoids." The .first sub-
group (A) would then include the protocatechuic-tannides or
-tannoids, and the second (B) would comprise the gallic- tannides
or -tannoids. In working out a system of classification of this
kind Kunz-Krause (Swheiz. Woch. f. Chem. u. Pharm., 1898, p.
424) has arranged all of the possible tannides or tannoids and
has given the formulae for a number which have not yet been
found in nature.

CHEMICAL PROPERTIES OF TANNINS. — The tannins are amor-
phous substances and do not form crystalline salts. They are
soluble in water, alcohol, ethyl acetate, or a mixture of alcohol
and ether. They are almost insoluble in anhydrous ether, chloro-
form, and the other immiscible solvents. The solutions give dis-
tinct color reactions or precipitates with ferric chloride, stannous
chloride, and acetates of copper and lead. They form soluble
compounds with iodine and prevent the latter from giving the
characteristic blue reaction with starch. Solutions of tannin
give insoluble precipitates with cinchonine and other organic
bases. Tannins are, furthermore, especially in alkaline solutions,
powerful reducing agents, their resulting products being of a
dark red or yellowish-red color.

Upon treatment of tannins with dilute acids, or fusing with
the alkali hydroxides, or heating alone, several classes of products
are formed.

I. When heated in a sealed tube at 100° C. solutions of tannin
in a I per cent, solution of hydrochloric acid yield either crystal-
lizable acids, or phlobaphenes, or insoluble red substances. (A)
The following glucosidal tannins yield crystallizable acids : The
tannin from nut-galls, divi-divi (fruit of Casalpinia coriaria),
myrobalans (fruit of Terminalia Chebula), rind of pomegranate
fruit, and coffee. (B) Phlobaphene is a reddish, or brownish-red,
amorphous substance formed from the tannin of willow bark. It
is insoluble in water but soluble in alcohol, dilute solutions of
the alkalies and alkali carbonates, and solutions of borax. (C)

204 A TEXT-BOOK OF BOTANY.

Quite a number of tannins yield a reddish, amorphous substance
which precipitates out of the acid solution and is insoluble in
water, alcohol, and solutions of the alkalies. Derivatives of this
kind are obtained from the tannin of kino, krameria, etc.

2. When tannins are fused with potassium or sodium hydrox-
ide several classes of products are formed, depending on the con-
stitution of the tannin. (A) Protocatechuic acid is formed not
only on the fusion of certain tannins, but may be prepared from
other plant substances, as vanillin, asafoetida, myrrh, etc.
Usually other substances are formed in the interaction, these
being either acetic acid or phloroglucinol. In this class are in-
cluded the most of the tannins, which on heating with dilute
acids yield either phlobaphenes or insoluble red substances. (B)
Pyrogallol, which is commercially prepared by the dry distillation
of gallic acid, is also formed from the glucosidal tannins which
yield crystallizable acids in acid solutions.

3. Upon carefully heating tannins .to a temperature of 190°
to 200° C. they are decomposed and yield two distinct classes of
derivatives, being either (A) pyrocatechol (a diatomic phenol)
or (B) pyrogallol (a triatomic phenol). Both of these substances
are crystalline and may be sublimed unchanged. They are,
furthermore, both soluble in water, alcohol, and ether, and are
distinguished by giving very characteristic reactions with certain
reagents. Solutions of pyrocatechol are colored dark green with
ferric-alum and greenish with copper sulphate + ammonium
hydrate, or concentrated sulphuric acid. Pyrogallol is colored
bluish-black with ferric-alum, becoming green and finally brown ;
brownish with copper sulphate + ammonium hydrate, or sul-
phuric acid, and becoming violet with lime water, rapidly chang-
ing to brown. Pyrocatechol is formed from those tannins which
produce protocatechuic acids on fusion with potassium hydroxide
and phlobaphenes or insoluble red substances on treatment with
acids. Pyrogallol is formed on heating those tannins which also
yield pyrogallol on fusion with potassium hydroxide and yield
either gallic acid or ellagic acid on hydrolysis with acids.

MICROCHEMISTRY OF TANNINS. — Tannin ocurs as a constituent
of the cell-sap, and the cells containing it may be determined by
use of dilute solutions of methylene blue, as proposed by Pfeffer,

CELL-CONTENTS AND FORMS OF CELLS. 205

which colors the cell-sap blue, afterward precipitating the tannin.
This reagent has the advantage that when used in very dilute
solution ( i part methylene blue to 500,000 of water) it does not
injure the protoplasm of the living cells, so that the cut end of a
twig may be placed in the solution for I to 24 hours and sections
examined from time to time. Another reagent that is very
satisfactory in the examination of living material is a solution of
ammonium carbonate, which causes a precipitation of the tannin
in the cells in the form of very small globules or rods. This solu-
tion may be used either directly upon sections or by placing freshly
cut stems in dilute solutions ( I part ammonium carbonate and
200 parts water). Ammonium carbonate does not precipitate
gallic acid and therefore may be advantageously used in the study
of the development of tannin and related substances, as in galls.
The following reagents also give distinct reactions for tannin.
Copper acetate in concentrated aqueous solutions is one of the
very best reagents for the localization of tannin cells. It is em-
ployed by allowing the leaves or twigs to remain in the solution
for some days, when the tannin forms a reddish-brown precipitate
in the cells. Ferric chloride and ferric acetate also precipitate
tannin. Moeller has suggested the use of a solution of iron
chloride in anhydrous ether, the cut pieces of the stems and leaves
being placed directly in this reagent. Potassium bichromate and
chromic acid in dilute solutions give yellowish-brown or blackish-
brown precipitate with tannin.

DISTRIBUTION OF TANNIN. — There are very few plants in
which tannin does not occur in some of the parts or at least in cer-
tain cells during some period in their development. This is fre-
quently noted in making sections of plant material with a razor ; the
liberated cell-sap is colored a dark blue. It is found in the form of
highly refracting globules in the Zygnemaceae and other Algae. It
occurs in relatively large amounts in some of the ferns, and, with
the exception of the Monocotyledons, is widely distributed in the
Spermophytes. As tannin is widely used in the making of leather
and as a mordant .in dyeing, etc., it is extracted from various
plants and is an article of commerce. The following are some
of the important tannin-yielding plants: The bark of hemlock
(Tsuga canadensis, Fam. Pinaceae) yields nearly 14 per cent, of

206 A TEXT-BOOK OF BOTANY.

tannin; the bark of several species of Pinus (Fam. Pinacese)
growing in southern Europe yields 7 to 10 per cent, of tannin;
the barks of the white spruce (Picea canadensis) of Canada, of
the larch (Larix laricina) of northern and northwestern part of
United States and Canada, and of the fir (Abies balsamea) yield
similar amounts of tannin as the barks of hemlock and pine. The
wood of chestnut (Castanea dentata, Fam. Fagaceae) yields 8' to
10 per cent, of tannin ; the bark of several species of Salix (Fam.
Salicacese) growing in northern Europe yields 3 to 12 per cent,
of tannin ; the bark of chestnut oak, white oak, red oak, etc.
(Fagacese), yields 12 to 15 per cent, of tannin; the scaly in-
volucres or acorn-cups (under the name of " Valonia ") of
several species of Quercus growing in southern Europe and
Levant yield 25 to 35 per cent, of tannin ; the fruit of Terminalia
Chebula (under the name of " Myrobalans ") yields 35 to 40
per cent, of tannin ; the stems and leaves of several species of Rhus
(Anacardiacese) yield 16 to 24 per cent, of tannin; the fruit of
Ccesalpinia coriaria (Fam. Leguminosse) (under the name of
"divi-divi") yields 30 to 50 per cent, of tannin; the wood and
the bark of several species of Schinopsis (Fam. Apocynaceae)
growing in South America yield from 15 to 23 per cent, of tannin,
which is usually found in commerce in the form of an extract
known as " Quebracho Extract " ; the bark of the common horse-
chestnut (Aisculus Hippocastanum, Fam. Sapindaceae) yields
considerable tannin, and is employed in Italy ; the bark of Myrica
Nagi (Fam. Myricaceae) contains n to 14 per cent, of tannin;
the bark of Malpighia glabra (Malpighiaceae) (under the name
of "Nance bark") is used in Mexico and yields about 26 per
cent, of tannin; the bark of Stryphnodendron polyphyllum (Fam.
Leguminosae) yields about 30 per cent, tannin. The tannin of a
number of other plants has been investigated, some of these being
used in medicine, as granatum, catechu, kino, krameria, tor-
mentilla, gambir, etc. (see Vol. II).

GALLS. — There are a number of excrescences, found upon the
leaves and twigs of a number of plants, termed galls. These result
from injuries caused chiefly by insects, and are therefore in the
nature of pathological products. Galls which are formed on
trees which in themselves contain considerable tannin usually

CELL-CONTENTS AND FORMS OF CELLS. 207

yield very large amounts of tannin. Nut-galls formed on certain
species of oak yield 65 per cent, of tannin. The Japanese galls
and Chinese galls formed on the leaf stalks and young branches
of some species of Rhus contain about 70 per cent, of tannin.
The galls found occasionally on sumach (Rhus glabra), a shrub
abundant in North America, yield over 60 per cent, of tannic
acid. The tannins obtained from excrescences of this character
were at one time called " pathological tannins," to distinguish
them from the tannins formed naturally in the living plant, and
which were called " physiological tannins." In the light of the
studies on the several tannins this . terminology is no longer
accepted.

INCLUSION CELLS AND TANNIN IDIOBLASTS. — In a number of
plants occur special cells which vary considerably in form and con-
tents, but are distinguished by giving reactions for tannin. In-
clusion cells were first described by Fliickiger in the fruit of
Ceratonia Siliqua. These occur in the form of long tubes, which
are easily separated from the pulp, and the yellowish contents
are colored blue with solutions of ferrous sulphate or ferric
chloride. Recently Hanausek has contributed several papers on
the distribution of inclusion cells in a number of different plants.
In the leaves of Pistacia Lentiscus he found (Ber. d. d. Bot. Ges.,
1914, p. 117) that the upper row of palisade cells and the loose
mesophyll cells (Fig. 114, A) contain numerous somewhat
elongated, transversely striated bodies, which completely fill the
cells. These are colored dark green or blackish with ferric
chloride and a pale violet with a solution of potassium hydrate.
The contents dissolve on heating, changing to a brownish color.
They are also partly soluble in concentrated sulphuric acid, and
with solutions of vanillin + hydrochloric acid the contents are
colored red. They are not completely soluble in hot solutions of
potassium hydroxide, there always remaining a small, colorless
portion. The inclusions in the date (Fig. 114, B) and tamarind
resemble those found in the fruit of St. John's Bread (Ceratonia)
and leaves of Pistacia. Inclusions have been found in the seed
coat of Pimenta and one or more fruits in the following families :
Anonacese, Anacardiacese, Ebenaceae, Elseagnacese, Leguminosse,
Palmse, Rhamnacese, and Rosaceae.

208

A TEXT-BOOK OF BOTANY.

TANNIN IDIOBLASTS were first observed by Zopf in a number
of genera of the Fumariaceae (Fig. 115). These are somewhat
analogous to and resemble the latex or pigment cells in the Papa-
veracese. They develop in the meristematic cells of certain tissue
systems and remain constant throughout the life of the plant. The

FIG. 114. Inclusion Cells: A, section of leaf or Pistacia Lentiscus showing numerous
inclusion cells (in) in the upper palisade layer and cells of mesophyll; calcium oxalate
(kr); palisade layers (pa) ; loose mesophyll (m) ; fibro vascular bundle (i); upper epidermis
(ep); granules of fatty substance (i); lower epidermis (ep); stoma (sp). B, Inclusion cells
or tubes (k, 1, m) in the fruit of the date palm; k, showing a homogeneous amorphous
content; 1 and m, separation of irregular inclusion masses in form of projections from the
wall. — After Hanausek.

cells vary in shape, composition of wall, and color of contents.
They may be either short, isolated cells or occur in chains; or
they may become elongated, resembling fibers. The walls may be
composed of cellulose or contain a certain amount of lignin or
suberin. Some of the cells may contain a nucleus. The cell-sap

CELL-CONTENTS AND FORMS OF CELLS. 209
A D

FIG. 115. Idioblasts containing tannin and anthocyanin: A-D, idioblasts in primary
cortex of root of Corydalis ochroleuca, showing a short, thin-walled cell with reddish sap
(A, t), and a long fiber with yellowish content (A, e); three short, thick- walled idioblasts
(B) with a reddish cell-sap; a short fiber with yellowish contents (C) and transverse sections,
through an idioblast (D), showing the thick, porous walls. E, a portion of an idioblast,
with thick, porous walls, from the pith of Fumaria muralis. F to H, idioblasts in Parnassia
palustris; F, portion of epidermis of leaf showing 5 idioblasts (t) with colorless but highly
refracting tannin content; G, portion of epidermal layer of corolla tube with reddish an-
thocyanin idioblasts (t); H, portion of epidermal layer at the base of corolla tube with
very long idioblasts (t) containing a red-colored cell-sap. — After W. Zopf, "tfber die
Gerbstoff- und Anthocyan-Behalter der Fumariaceen und einiger anderen Pflanzen,"
in Bibliotheca Botanica.

14

210 A TEXT-BOOK OF BOTANY.

may be either colorless or of an intensely yellow or bright red
color, giving a distinct reaction for tannin. The cell-sap is soluble
in water and in alcohol and gives an acid reaction. In the yellow
idioblasts upon treatment with nitric acid it is colored orange-red,
changing to reddish-brown ; with concentrated sulphuric acid it
becomes orange-red and finally of a rose-red or crimson
color; with solutions of the alkalies it becomes greenish, and it is
precipitated with solutions of potassium bichromate, ferric acetate,
or ferrous sulphate, the precipitates resembling those found with
tannin. Zopf found that the tannin idioblasts may possess either
a colorless content or, in addition, have a yellow coloring prin-
ciple (yellow anthocyanin) or a red pigment (red anthocyanin).
He considers that the yellow pigment is derived from a colorless
chromogen and that the red pigment may be formed from either
a colorless chromogen or from yellow anthocyanin. Further-
more, he concludes that there is a relationship in the Fumariaceae
between the anthocyanin and tannin, as the two constituents are
always found in the same cell. It is rather interesting to note
that chloroplasts may be found in the idioblasts, and that sugar
is also a constituent in the idioblasts, occurring in the young roots
and stems of Diclytra spectabilis.

Tannin idioblasts are found in the palisade tissues of leaves
or in the parenchyma cells of roots and stems of some of the
genera in the Geraniaceae, Celastraceae, Rhamnaceae, Legumi-
nosse, Solanaceae, Rubiaceae, Scrophulariaceae, Polygonacese,
Aristolochiaceae, Piperaceae, Euphorbiaceae and Moraceae.

THE FIXED OILS, FATS, AND WAXES include a group of sub-
stances which are widely distributed in plants, occurring especially
abundant in seeds, fruits, and barks. They are distinguished by
the fact that in their chemical constitution they possess radicals
of the fatty acids. In the diatoms, Vaucheria, and some of the
other lower plants fixed oils arise in the chromatophores in place
of starch, thus being the first visible product of photosynthesis.
Fixed oils usually occur in reserve cells as in seeds and the
parenchyma and medullary ray cells of roots and rhizomes. They
are either found in the vacuoles of the protoplasm or are formed
in the cell-wall, and usually are liberated in the form of globules
upon healing the sections or treating them with solutions of

CELL-CONTENTS AND FORMS OF CELLS. 211

hydrated chloral or sulphuric acid. The fixed oils remain
liquid at ordinary temperatures, whereas the fats tend to solidify,
and are occasionally found in the form of crystals in plant cells
(Fig. 116). ' Both of these classes are fatty acid-esters of
glycerin, whereas the waxes are combinations of fatty acids and

FIG. 116. Crystals of fixed oils: A, section of seed of the oil palm (Elceis guineensis)
treated with an alcoholic solution of iodine and very dilute sulphuric acid, showing stone
cells (sc) ; cells with homogeneous brown content (sa) ; cells with yellowish granular content
(sa'); and cells of endosperm (en) hav;.ng porous walls (x), and containing phytoglobulins
(crystalloids) (P, p), associated with needle aggregates of the fatty acids. B, cross section
of a cotyledon of cacao, heated in a solution of potassium hydroxide, showing the epidermal
layer (ep) with hair (d), phytoglobulin (crystalloids) (al) and aggregates of fatty acids (f).
C, a few cells of the cotyledons of ripe cacao seeds mounted in glycerin, showing separation
of sphere-crystals of fatty acids in the oil and starch-bearing cells of endosperm. — After
Hanausek.

some alcohol other than glycerol (glycerin). According to this
distinction some waxes as myrtle wax, obtained from the berries
of Myrica cerifera, are classed among the fats, it being a mixed
glyceride of palmitic and lauric acids.

The fatty acids which enter into the constitution of the fixed
oils and fats belong to more than one series of hydrocarbons.

212 A TEXT-BOOK OF BOTANY.

The following acids are present in the vegetable oils and fat.
Normal caproic acid (C6H12O2), Caprylic acid (C8H16O2), and
Capric acid (C10H20O2) are found in cocoa-nut oil, expressed
from the seeds of the cocoa-nut (Cocos nucifera), and in palm-
nut oil, obtained from the oily sarcocarp of the drupes of the
palm, Elais guineensis.

LAURIC ACID (C12H24O2) occurs in laurel-nut, obtained from
the seeds of Calophyllum Inophyllum (Fam. Guttiferse), a plant
growing in the East Indies and Cochin China. It is also found in
cocoa-nut oil and certain other vegetable oils.

MYRISTIC ACID (C14H28O2) is found in certain vegetable fats,
especially in nutmeg and mace. This oil forms crystalline salts
with both potassium and barium.

PALMITIC ACID (C16H32O2) occurs combined with glycerol in
a large number of vegetable oils, especially in palm-nut oil, and
Japan wax. The latter is obtained from fruits of Rhus vernicifera
and R. chinensis. It is also found in myrtle wax, which occurs
as an incrustation on the fruits of the wax myrtle (Myrica
cerifera) and bayberry (M. carolinensis) . This acid is not very
readily soluble in petroleum ether. A crystalline silver salt is
obtained by adding an alcoholic solution of silver nitrate to an
alcoholic solution of ammonium palmitate.

STEARIC ACID (C18H36O2) occurs as a glyceride in cacao butter
obtained from chocolate seeds, and in " Shea butter " obtained
from the seeds of Butyrospennum Parkii, a tree growing in Upper
Guinea and in the region of the Nile.

ARACHIDIC ACID (C20H40O2) occurs combined with glycerol in
peanut oil and other vegetable fats. The acid is soluble in boiling
alcohol, ether chloroform, benzene, and petroleum ether. It
forms crystalline salts of copper and silver.

BEHENIC ACID (C22H44O2) occurs as a glyceride in "oil of
Ben " expressed from the seeds of Moringa pterygosperma, a
plant of the East and West Indies. This oil is used for the
preparation of cosmetics, by perfumers for extracting odorous
substances, and as a lubricating oil for clocks.

LIGNOCERIC ACID (C24H48O2) occurs as a glyceride in peanut
oil, and is distinguished from arachidic acid in being slightly
soluble in cold alcohol.

CELL-CONTENTS AND FORMS OF CELLS. 213

TIGLIC ACID (C5H8O4) occurs as a glyceride in croton oil,
and is soluble in water.

HYPCXLEIC ACID (C16H30O2) occurs combined with glycerol in
peanut oil and in corn oil. It is soluble in cold alcohol and
crystallizes in needles.

LYCOPODIC ACID occurs, as a glyceride, in lycopodium spores,
and is related to hypogseic acid.

OLEIC ACID (C18H34O2) occurs as a glyceride in many vege-
table oils. The glyceride of oleic acid occurs, as a rule, in larger
quantities in most fixed oils than any other glyceride, being present
in olive oil to the extent of 90 per cent. It is also found in a large
number of seeds, principally in cotton seed, hazel-nut, peanut,
sesame, walnut, corn, tea seed, almond, and the kernels of
apricot, peach, and plum. These oils are generally grouped to-
gether and known as the " olive oil group." The sodium and
barium salts of oleic acid are crystalline.

RAPIC ACID (C18H34O2) and ERUCIC ACID (C22H42O2) occur
combined with glycerol in the oil obtained from rape or colza
seed and in other Cruciferous seeds.

LINOLEIC ACID (C18H32O2) is the principal acid of the gly-
cerides forming the " linseed oil group " or " drying oils." The
acid which is best known is that obtained from flaxseed or
linseed, the oil of which contains from 80 to 85 per cent, of
linoleic acid or its isomers. Linoleic acid is also present in the
fixed oil occurring in the seeds of the following plants : Hemp,
walnut, pine (Pinus sylvestris), fir (Abies balsamea), poppy,
sarBower, sunflower, and seeds of a number of species of
Aleurites. The seeds of Aleurites moluccana yield the " candle
nut oil " of the South Sea Islands, and the seeds of A. cor data
yield the " tung oil " (Chinese wood oil or Japanese wood oil) of
China and Japan.

RICINOLEIC ACID (C18H34O3) occurs as a glyceride in castor
oil, and is the principal constituent of this oil. It is also present
in the seeds of other Euphorbiaceous plants, being found in croton,
curcas, etc., and is also found in grape seed. Ricinoleic acid is
soluble in alcohol and ether and is insoluble in petroleum ether. It
forms crystalline salts with barium, calcium, and lead.

JAPANIC ACID (C,2H42O4) is the only dibasic acid occurring

A TEXT-BOOK OF BOTANY.

in natural fats, and is found in Japan wax. The crystals, formed
from the solutions in alcohol or chloroform, are heavier than
water.

CHAULMOOGRIC ACID (C18H32O2) occurs as a glyceride in
chaulmoogra oil, being obtained from the seeds of Taraktogenos
Kurzii and other plants of the Bixaceae. It has the composition
of linoleic acid, but a study of its constitution shows that it is in
the nature of a cyclic compound.

The following alcohols occur as esters in vegetable waxes :
Ceryl alcohol (C26H54O), combined with palmitic acid, is the
principal constituent in opium wax. Ceryl alcohol is also present
in carnauba wax, which is obtained from the leaves of the Car-
nauba-palm (Copernicia cerifera). Carnauba wax also contains
myricyl or melissyl alcohol (C30H62O), the latter being either
free or combined as an ester of cerotic acid.

PHYTOSTEROL, a compound isomeric with cholesterol
(C27H46O), is found in the oils derived from a number of seeds.
It is unsaponifiable, and is found in the extracted oils to the extent
of about i per cent. Phytosterol crystallizes in the monoclinic
system (Fig. 117), whereas cholesterol, which occurs in most ani-
mal oils and fats, forms triclinic plates resembling rhombic prisms
(Bomer, Zeits. f. Unter. d. Nahr- u. Genussmittel, 1898, p. 42).

LECITHIN belongs to a group of fatty substances containing
nitrogen and phosphorus, and in which the latter is present as
glycerophosphoric acid. They are sometimes grouped together
in a special class, known as " phosphatides," and are characterized
by containing one or more molecules of phosphoric acid, an alcohol
(as glycerin), one or more fatty acid radicals (as stearic or oleic
acid), and one or more nitrogenous bodies (such as choline and
allied substances). Lecithin occurs in seeds, buds, and young
shoots. In barley, wheat, and rye it occurs to the extent of 0.6 per
cent. ; in peas, 1.2 per cent. ; lupine seeds, 2 per cent. ; mushrooms,
0.9 per cent. ; dry yeast, 2 per cent. (For amount in other plants
see Amer. Jour. Pharm., 1914, p. 169.) According to Stoklasa, the
phosphoric acid of plants occurs in the form of organic com-
pounds, of which lecithin is an important example. It is formed
in those organs and under those conditions where photosynthesis
is possible. It is even thought that lecithin may be a product

CELL-CONTENTS AND FORMS OF CELLS. 215

of assimilation in the chloroplastid. The fact that fungi con-
tain it shows that lecithin may be formed from protoplasm itself.
It is one of the most interesting compounds which has been
isolated from plants, and no doubt plays an important role in
the life of the cell.

Lecithin is a yellow, viscous, waxy substance soluble in oils

w

FIG. 117. Phytosterol allowed to crystallize very slowly from strong alcoholic solu-
tions, the crystals being recrystallized until the melting-point is constant. I, crystal forms
with parallel extinction C D. II, crystals with parallel extinction B C. Ill, crystals with
parallel extinction along the long axis. IV, common crystal forms of phytosterol. Phytosterol
is a constituent of most vegetable oils and is most abundant in peas, lentils, and other
Leguminous seeds. The presence of vegetable oils is detected in animal oils by a study
of the forms of crystals, those of phytosterol crystallizing in the monoclinic system, whereas
cholesterol forms crystals which belong to the triclinic system. — After A. Bomer, in Zei'/s.
/. Unter. d. Nahr.- u. Genussmittel, 1898, p. 45.

and warm alcohol. In solutions of ether or chloroform it is pre-
cipitated upon the addition of acetone. In contact with water, it
separates in the form of spiral threads or loops, giving rise to the
" myelin forms " of Kirchow and Beneke. When examined
under the microscope a smear of lecithin, to which a drop of
water or a sugar solution has been added, sends out a number of

216 A TEXT-BOOK OF BOTANY.

rounded projections which gradually elongate and become more
and more abundant and intricate. If this process be allowed to
take place in a test-tube or other vessel that can be shaken, the
water becomes turbid through the dispersion of the delicate
microscopic myelin protrusions, and in course of time a uniform
emulsion of the lecithin in water is obtained, which consists of fine
swollen particles. This is a colloidal solution that can be filtered
without change. It is not coagulated by heat, nor precipitated by
salts of monobasic or tribasic metals.

WAX. — The epidermal layer of the plant shows a number of
modifications. It usually consists of an inner layer of cellulose
and an outer covering of cutin. While some of the lamellae be-
neath the cutin may be modified to mucilage or oil, the surface
of the cutin layer may have deposited upon it a coating of 'wax.
Frequently the wax is in such small quantities that it is not ob-
served until the sections are heated to a temperature of 90° to
100° C, when the wax separates in the form of oily globules.
According to De Bary, there are four principal forms of wax-
coatings.

i. It occurs in the form of minute rods or needles, such as are
found constituting the bloom of fruits as the grape and plum,
and the stems and leaves of Eucalyptus Globulus, Ricinus corn-
munis, etc. 2. The most common form is a simple, granular
coating consisting of isolated grains which may lie together as a
single layer. These are found in the fruits of some of the
Cruciferae, Iris pallida, etc. 3. The coating may consist of
minute rods which may be more or less bent or curled, standing
perpendicularly on the cuticle, as in the sugar cane, canna, banana
plant, etc. 4. The wax incrustation may occur in the form of
membrane-like layers, varying from thin scales, as in Taxus
baccata, Portulaca oleracea, and various cacti, to thick layers
showing a striation and stratification similar to that found in
thick-walled cells, as in the fruit of Myrica, leaves of the wax
palm (Ceroxylon andicolum). According to Wiesner, the deposit
of wax is often crystalline, appearing in four-sided prisms. (Con-
sult A. deBary, " Comparative Anatomy of the Organs of
Vegetation.")

PHYSIOLOGY OF FATS. — It is stated that in the photosynthetic

CELL-CONTENTS AND FORMS OF CELLS. 217

processes of some of the lower plants, as Vaucheria, Diatoms, etc.,
fixed oils rather than starch are formed in the chromatophores.
It is well known that in the cells of the bark of a number of plants
fixed oils are stored in place of carbohydrates. These facts show
that there is a very intimate relationship between the fixed oils and
other metabolic substances. Fixed oils constitute the reserve
materials in seeds, spores, pollen grains, and are even present in
the tubers of certain plants as Cyperus esculentus. The storing
of fixed oils instead of starch may be of some advantage to plants,
in that there is a greater supply of energy contained in them than is
present in the same quantity of any of the carbohydrates. Again,,
as the specific gravity of the fixed oils is less than that of the carbo-
hydrates, this is an advantage in those spores or seeds which are
disseminated by the wind and require to be as light as possible.

The fixed oils are more or less intimately associated with the
protoplasm occurring in vacuoles of the same in fruits and seeds.
The waxes which are secreted in the epidermal cells of leaves and
green stems, and also found as a covering of many fruits, serve to
protect the underlying cells from loss or excess of moisture,
from the attack of disease-producing micro-organisms, and also
prevent the interactions caused by some of their enzymes. The
resistance of certain micro-organisms, as the tubercle-bacilli, is
supposed to be due to some extent to the fatty substances in which
their bodies are enclosed or with which they are impregnated.
" It is held by some that the fats, or, more correctly, the lecithin
and phospholipines, are essential to the cohesion and physical
constitution of the protoplasm, so that any interference with the
physical state of these substances arrests the vital functions. The
cement which binds the organized matter together is loosened by
the solution in it of foreign substances, and it is the loosening
of the protoplasmic cement that makes it possible for the normal
processes of life to be carried on.

" Attempts to form a concrete conception of the physical rela-
tionship in the structural organization of cells between fats on the
one hand and the other constituents of living matter on the other
have not been successful. Some have spoken of ' lipoid mem-
branes ' as if the living cell itself were enclosed in a fatty envelope
and accessible only to such substances as can permeate this envelope

218 A TEXT-BOOK OF BOTANY.

through chemical affinities with the fatty material of which it is
composed. Others are inclined to think of protoplasm as an
emulsion of proteins and ' lipoids.' Loeb and v. Knaff Lenz find
that sea-urchin eggs are liable to undergo cytolysis under the
action of any process, chemical or physical, that causes the cell
fats to become more fluid." (Consult J. B. Leathes, "The
Fats.")

Mucilages and Gums. — By the terms mucilages and gums are
meant those substances which are soluble in water, or swell very
perceptibly in it, and which, upon the addition of alcohol, are
precipitated in the form of a more or less amorphous or granular
mass. Mucilage originates in the plant as a cell-content, or as a
modification of the wall. In the former case it arises as a product
of the protoplasm, or it may be a disorganization product of some
of the carbohydrates. When it arises through modification of
the wall it is spoken of as " membrane mucilage," and owes its
origin to several causes : either to a secondary thickening of or an
addition to the cell wall, or a metamorphosis of it, at least in part.
In the latter case it may arise either as a disorganization product
of the primary wall, or of the subsequent lamellae making up the
walls of the cells of the medullary rays, parenchyma, and other
tissues, as in Astragalus gummifer (Fig. 118), or it may arise
as an intercellular substance.

The following is a classification of some plants, based upon
the origin of the mucilage:

I. Mucilage in the form of a cell-content is. of infrequent
occurrence in plants. It is usually present in the cells containing
raphides, especially in the Monocotyledons. Its orgin and de-
velopment may be easily followed in the tubers of a number ofj
Orchids, especially those yielding salep. The mucilage arises very
early in the development of the cells surrounding the crystal-
groups, and continues to be formed as the crystals grow in size,
the protoplasm and nucleus being reduced to a very thin, layer
which lie next to the cell-wall. The mucilage of salep is colored
yellowish with iodine and sulphuric acid, or a yellowish-red or
rose-red with aqueous eosin solution, and a carmine-red with an
aqueous solution of Congo red. The cells containing mucilage are
easily differentiated from the surrounding cells by the use of

CELL-CONTENTS AND FORMS OF CELLS. 219

alcoholic solutions of Congo red, methylene blue, etc., which dis-
tinctly color the mucilage in them. Cell-content mucilages are also
found in the fleshy scales of the onion, the rhizome of Agropyron
repens, the fleshy leaves of Aloe and other succulent plants. It

ms

mst

m

FIG. 118. Cross section through pith (m) and the inner portion of the wood (lt>) of
Astragalus gummifer, showing successive stages in the modification of the walls in the
formation of gum tragacanth (o, i, 2, 3, 4). Some of the tracheae (c) contain globular
masses of gum. — After Tschirch.

probably also occurs in this form in the Cyanophyceae and in
some of the red algae, as Laminaria, although in the latter it is
formed chiefly as a modification of a cell-wall and the intercellular
substance. In Dicotyledons the mucilage which is present is

220

A TEXT-BOOK OF BOTANY.

usually formed as a modification of the cell-wall, and, according
to Solereder, it seems to occur in the contents of the cell in only
the following families : CEnotheraceae. Rubiaceae, and Vitaceae, in

FIG. 119. Cell- wall mucilage. A, transverse section of seed-coat of flaxseed treated
with water, showing the swelling of the mucilaginous layer situated beneath the cutin;
B, section of Althaea root showing three large mucilage-cells; C, transverse section of elm
bark showing four large mucilage-cells.

all of which the mucilage receptacles can be interpreted as being
incompletely differentiated raphide-sacs, — i.e., without raphides.
II. Cell-membrane mucilage, — i.e., mucilage formed as a

CELL-CONTENTS AND FORMS OF CELLS. 221

result of a metamorphosis of the cell-wall, — is of frequent occur-
rence, being found in all parts of the plant, including the endo-
sperm cells of seeds, parenchyma cells and medullary ray cells of
roots and stems, and epidermal cells of leaves, stems, fruits, and
seeds. Cell-membrane mucilage is also found in some of the
mucilaginous marine algae, as chondrus laminaria, etc., although
in the latter case the mucilage is often spoken of as being derived
from the intercellular substance, being a modification of the

FIG. 120. A, B, C, successive stages in the development of the mucilage hairs or glands
on the lobes of the leaves of Viola tricolor; D, young secretion hair showing some of the cells
with large nuclei and several vacuoles; E, mature hair; F, gland showing mucilaginous layer
beneath the cutin and the protrusion of a portion of the mucilage through the broken wall;
G, portion of leaf on the upper part of the lobes of which occur the mucilage glands.

primary wall. It may also occur as a result of a decomposition of
the secondary lamellae.

Four different forms of mucilage are recognized. I. Mucilage
cells, or distinct cells resembling more or less the surrounding
cells, except that they contain mucilage, occur in the tissues of
leaves, petals, fruits, seeds, and the parenchyma cells of pith
and primary cortex of a number of plants. In this group may also
be included the gelatinized cells of the integumental tissues

222 A TEXT-BOOK OF BOTANY.

(epidermis and hypodermis), as these in many cases may be
mistaken, as in the Violaceae, for distinct cells, although only the
inner walls of the epidermal cells are gelatinized. 2. Mucilage
cavities arise from the simultaneous gelatinization in the walls
of a group of cells. These are found in the cells of the pith,
cortex, and petioles in a, number of plants of the Malvaceae,
Sterculiaceae, Simarubaceae, etc. 3. Mucilage canals are large
cavities formed either (A) as a result of the enlargement of the
intercellular spaces between the cells, the primary lamellae being
modified to mucilage; or (B) are formed by the disintegration or
breaking down of a number of cells, the walls of which become
gelatinized. In the former case they are spoken of as " schizog-
enous canals," and in the latter as " lysigenous canals." The
latter are the more common form and occur in the pith and
primary cortex of a number of plants belonging to the Guttiferae,
Malvaceae, Sterculiaceae, Oleaceae, Rhamnaceae, Vitaceae, Legumi-
nosae, Rosaceae, Cactaceae, Piperaceae, Moraceae, and Urticaceae.
4. Glandular hairs (Druzenzotten) . In this form (Fig. 118)
they are found in the lobes of the leaves and calyces of Viola
tricolor, Coffea arabica, and of Prunus avium.

CHEMICAL CLASSIFICATION OF MUCILAGE. — Mucilages may
be distinguished, according to their behavior with special reagents,
as cellulose-mucilages or pectose-mucilages. The former are
colored blue by chlor-zinc-iodide, and are soluble in ammoniacal
solution of cupric oxide. To this class belong the mucilages of
the tuber of salep and the seeds of cydonium. The pectose-
mucilages are distinguished by the fact that they are dissolved
on being heated with solutions containing from 35 to 65 per cent,
cane sugar. They are also stained intensely with solutions of
saffranin, methylene blue, .or ruthenium red.

Mucilage is formed in large quantities in certain trees, and the
exudation which is collected forms the so-called gums of com-
merce. As these are largely used for a variety of technical pur-
poses, their chemical properties have been studied, so that four
distinct classes of gums are recognized.

i. Gums containing arabin or arabic acid. In this group are
included gum arabic, obtained from Acacia Senegal and other
species of Acacia ; Feronia gum, obtained from Feronia elephan-

CELL-CONTENTS AND FORMS OF CELLS 223

turn (Fam. Rutaceae), and Anacardium gum, obtained from
Anacardium occidentale.

2. Gums consisting of mixtures of arabin and cerasin (cerasic
acid). To this group belong the exudations formed on a number
of trees of the Rosaceae, as cherry, almond, apricot, and plum.

3. Gums containing bassorin. Tragacanth is the typical gum

FIG. 121. Citrus vulgaris. Longitudinal section of a young fresh fruit showing a lysig-
enous oil canal or duct. Se, oil; Zs, cell sap; PI, cells in which the walls have been dis-
solved; f, thin-walled cells; D, thick-walled cells; K, nucleus; Chr, chromoplasts ; o, crystals
of calcium oxalate; e, epidermis. — After Meyer.

of this class. Included in this group are a few other gums which
find some commercial use, as cocoa-palm gum, obtained from the
bark of the cocoa-nut palm; chagual gum, obtained from Puya
coarctata (Fam. Bromeliacese), and Moringa gum, obtained from
Moringa pterygosperma (Fam. Moringaceae).

4. Gums containing mixtures of cerasin and bassorin. The
East Indian gum, obtained from Cochlospermum Gossypium

224

A TEXT-BOOK OF BOTANY.

FIG. 122. Development of schizogenous oleo-resin canals in Brauneria pallida. A,
intercellular space (o) between four parenchyma cells, being the seat of the early formation
of the canal and indicated by a yellowish oily content. B, intercellular oleo-resin canal
with five surrounding parenchymatous cells (p). C, later stage of canal showing separation
of small oily globules in the intercellular substance. D and E, the intercellular substance
showing an almost protoplasmic-like structure, some of the lining cells being developed as
papillae and suggesting that they might be in the nature of secretion cells, although it is
now considered that the oils and resins of this character are formed from a resinogenous
layer in the wall. F, longitudinal section showing the elongated secretory canal between
the rows of cortical parenchyma.

CELL-CONTENTS AND FORMS OF CELLS 225

(Fam. Cochlospermaceae), has been used as a substitute and
adulterant of tragacanth.

VOLATILE OILS AND RESINS. — These and related products,
known as gum-resins and balsams,* are found in a very large
number of plants. Like the mucilages, they originate either as
a metamorphosis of the cell-wall or as a direct product of the
protoplasm. The former is of more frequent occurrence, and the

B

FIG. 123. Development of a lysigenous secretory canal in the leaves of Dictamnus
albus (Fam. Rutaceae). The development begins partly in the cells of the epidermal layer
and partly in the underlying parenchyma (A). The outer cells divide, forming the
secretion cells (c), while the inner give rise to the reservoir (B). The innermost cells then
multiply by repeated division in all directions, giving rise to a large number of cells containing
globules of oil (C). Later the thin walls are absorbed and the oily globules fuse together,
forming a single large globule (D). — After Rauter.

* The volatile oils are not infrequently associated with other sub-
stances of the plant cell in varying proportions, as resin, gums, cinnamic
and benzoic acids. Those products which consist chiefly of oil and resin
are known as OLEO-RESINS, and include turpentine and copaiba; those
consisting chiefly of gum and resin and containing but little volatile oil
are known as GUM-RESINS, and include ammoniac, asafoetida, galbanum,
and myrrh ; oleo-resins associated with aromatic acids are known as
BALSAMS, as balsam of Tolu, balsam of Peru, storax, and benzoin, which
latter is usually termed a balsamic resin.

15

226 A TEXT-BOOK OF BOTANY.

layer of the wall in which the decomposition takes place has been
termed by Tschirch a resinogenous layer.

The cells or receptacles which contain oils, resins, gum-resins,
and balsams are usually referred to as " secretory cells " or
" secretory receptacles." The latter term is used by Solejeder to
include all cells, cell fusions, cavities or canals which are filled
with secretions. Usually no attempt has been made to determine
whether the secretion is a volatile oil or a resin, or a gum-resin
or a balsam, as the appearance of the secretion is always either
in the form of globules or more or less rounded masses. Secretory
receptacles may arise in three different ways. ( I ) As a modi-
fication of the intercellular substance and an enlargement of the
intercellular areas, giving rise to schizogenous receptacles (Fig.
122). (2) As a result of a disintegration of a group of cells
and a decomposition of the wall substance, forming lysigenous
receptacles (Fig., 123). (3) They may have at. the outset a
schizogenous origin, but later the surrounding cells in addition
break down, so that the receptacle is more properly designated as
being schizo-lysigenous. In certain plants, as in the bark of
Sassafras and Cinnamon, there is a more or less even distribu-
tion of cells in the cortex, containing volatile oil, on the one hand,
and mucilage, on the other. Indeed, it is supposed that the cells
giving rise to mucilage may under different conditions develop
volatile oil. In a general way it may be said that the secretory
receptacles resemble those containing mucilage, both as to the
manner in which they originate in a plant and the physical char-
acters of the secretion. Indeed, they may be closely related to
the mucilages in that they may contain a large proportion of gum,
or the proportion of oleo-resin and gum may be reversed.

In the examination of technical products, and especially in
taxonomic work, it is very important to note not only the chemical
character of the secretions but also the fact whether the cells are
isolated or whether they form canals, or whether the secretory
receptacle is only a cavity. The following facts may be given in
reference to the four principal types of secretory receptacles :

i. Secretory cells are distinct cells which may be quite dis-
tinct from, or may show more or less resemblance to, their
neighboring cells, except that they contain oil or resin. They

CELL-CONTENTS AND FORMS OF CELLS/ 227

vary in length and outline, being either spherical, ellipsoidal, sac-
shaped (Fam. Bixaceae), or branched (Fam. Meliaceae). The
contents may be in the form of distinct globules adhering to the
wall (or in dried material may be in the form of -amorphous
masses), varying in color from colorless to yellowish or even dark
brown. In the secretory cells of certain plants of the Lauraceae,
Magnoliaceae, Canellaceae, Aristolochiaceae, and Piperaceae the
secretory contents are enveloped by a thin-walled sheath, con-
nected with the cell-wall by means of a stalk. The internal glandu-
lar hairs occurring in the rhizome of Dryopteris and in Pogoste-
nwn Patchouli may be included among secretory cells, although
they project into the intercellular area rather than into the cells.
The cell-wall of the secretory cells not infrequently gives a dis-
tinct reaction for suberin.

Elongated secretory cells or sacs, resembling tannin-idioblasts,
and with diverse contents varying from resin to latex-like sub-
stances or tannin-like. masses, are distributed in the cells of the
pith, bast, and pericycle of the stem and occasionally in the larger
veins of the leaves of some of the genera of the following families :
Anacardiaceae, Berberidaceae, Caprifoliaceae, Compositae, Crassu-
laceae, Euphorbiacese, Lecythidaceae, Leguminosae (very widely
distributed and with diverse contents), Menispermaceae, Monimi-
aceae, Myristicaceae, Passifloriaceae, Polygpnaceae, Rosaceae, and
.Rubiaceas.

Solereder also states that similar elongated sacs with brownish
contents are observed in the epidermal cells and occasionally in
the upper layers of mesophyll of one or more of the genera in
the following families : Crassulaceae, Euphorbiaceae, Geraniaceae,
Moraceae, Saxifragaceae, and Violaceae.

2. Secretory cavities are either spherical or ellipsoidal in shape
and the contents vary from oily or resinous to gum-like or tannin-
like masses. The mode of development of the cavities, as to
whether schizogenous, etc., is usually not considered, as this fact
is not easily determined in the mature tissues. When occurring
in leaves the cavities give rise to transparent dots or glandular
punctate areas. They are also found in the pith and primary
cortex of quite a number of plants.

There are a number of special forms of secretory cavities, the

228 A TEXT-BOOK OF BOTANY.

latter in some cases being lined by a papillose epithelium or a
form of bracket-cells, etc. They are found in the following fami-
lies: Araliaceae, Bixaceae, Caesalpinaceae, Compositae, Connaracese
(with sphaero-crystalline contents), Euphorbiaceae (with bracket-
epithelium), Geraniaceae (with sphaero-crystalline contents),
Guttiferae, Leguminosae (intramural glands with a papillose epi-
thelium or bracket-epithelium), Lythraceae, Malpighiaceae, Mal-
vaceae, Meliaceae, Menispermaceae, Myrtaceae, Oleaceae, Passi-
floriaceae, Piperaceae, Podostemaceae, Polygalaceae, Polygonaceae
(secretory cavities sometimes formed from four epidermal cells),
Primulaceae (occasionally with red crystalline contents), Pro-
teaceae (intramural glands), Rhamnaceae (with a papillose epi-
thelium), Rosaceae, Rubiaceae, Rutaceae, Simarubaceae, Styracaceae,
and Theaceae.

3. Secretory canals differ from secretory cavities in that they
are more or less elongated receptacles and often referred to as
oil-ducts or oil-tubes. Like the secretory canals, they originate
variously and have diverse contents. They may occur in a
number of different portions of a plant, but their distribution is
quite characteristic of certain genera or even of families. Secre-
tory canals have been observed in the following families : Ana-
cardiaceae, Araliaceae, Burseraceae, Cactaceae, Caesalpinaceae,
Celastraceae, Compositae, Gesneraceae, Guttiferae, Hamamelidaceae,
Leguminosae, Pittosporaceae, Podostemaceae, Rhamnaceae, Ruta-
ceae, Simarubacese, Theaceae, and Umbelliferae. (Consult Sole-
reder's "Systematic Anatomy of the Dicotyledons.")

4. Glandular hairs. Volatile oils and resins arise in the
glandular hairs formed on the surface of stems, leaves, and
various parts of the flower in the Labiatae, Compositae, and other
families. In these hairs a volatile oil separates in the form of
large, oily globules which lie between the cuticle and the outer
wal] of the underlying cells (Fig. 124). The origin of this secre-
tion has been variously ascribed to the protoplasmic content of the
cell or to a modification of the cell-wall. In the former case it is
said to arise as a metabolic substance in the protoplasm, and is
later diffused into the glandular area between the outer cellulose
wall and cuticle. While this manner of formation of the oily
secretion would seem reasonable, yet the studies by Tschirch

CELL-CONTENTS AND FORMS OF CELLS. 229

and Tunmann would seem to show that the secretion in the
glandular hair arises in a subcutaneous layer of the wall, which has
been termed a " resinogenous layer." Even De Bary, with char-
acteristic caution, has stated that the secretion found in the walls
of glandular hairs originates in the wall even though the ma-
terials for its formation must arise in the protoplasm of the cells.
In the study of glandular hairs the method of Tunmann may
be followed (Ber. d. d. pharm. Gesellsch., 1908', p. 513). Fresh,
or even dried, material may be used. Surface sections are made

FlG. 124. A glandular hair from the young leaves of Lavandula vera seen in different
stages in the course of three days, showing that the underlying cells remain of the same
size and structure, but that there is a gradual increase in the glandular area or resinogenous
layer. — After Tunmann.

and examined in aqueous solutions containing 10, 20, 30, or 40
per cent, of hydrated chloral. The 10 per cent, solution is used
first, then the 20 per cent., etc. The proper solution renders the
hair transparent, dissolves the resin, and, if the cover-glass is
moved sidewise, the cuticle bursts, showing the resinogenous
layer. Tunmann distinguishes three different types of glandu-
lar hairs, depending upon the character of this resinog-
enous layer, (i) In which by this treatment there separate
small rod-like crystals resembling bacteria, as in Fig. 125, A, B, C.
(2) A second type is given in which vacuoles occur consisting of

A TEXT-BOOK OF BOTANY.

rsg.

PIG. 125. Several forms of glandular hairs: i. In which the resinogenous layer (rsg)
separates in the form of small rods, as the leaves of violets (A), Fraxinus (B), and Alnus (C).
2. The resinogenous layer separating in the form of vacuoles in the hairs of Salvia (D)
and Hyssopus (E), observed in the dried material treated with dilute solutions of hydrated
chloral. 3. A lattice-like or cellular resinogenous layer occurring in the hairs of Rhodo-
dendron (F) and Azalea (G). — After Tunmann.

CELL-CONTENTS AND FORMS OF CELLS. 231

a fine net-work, as in Fig. 125, D, E. (3) A third type in which
the secretion is in the form of neither rods nor vacuoles but a
somewhat cellular structure, termed by Tunmann a lattice-work.
In the walls of the glandular hairs other substances are some-
times present, as resins, gums, etc. Hanstein originally pro-
posed the use of a mixture of aniline dyes to distinguish resin,
gum, and protoplasm (Bot. Zeit., 1868, p. 754), but later studies
have shown that these dyes are limited in differential diagnosis
of many of these substances. The cells of the glandular hairs
may contain, in addition to protoplasm, protein bodies, chloro-
phyll grains, starch, fixed oil, tannin, calcium oxalate, reducing
sugars, and other special substances, which are colored yellowish-
red with solutions of the alkalies or sulphuric acid.

MlCROCHEMISTRY OF THE VOLATILE OlLS AND RESINS. They

are readily soluble in alcohol, ether, chloroform, benzene, acetic
ether, carbon disulphide, petroleum ether, etc. They are also
quite soluble in glacial acetic acid and in aqueous solutions of
hydrated chloral. Some of them are soluble in dilute alcohol.
They may be liberated on the heating of sections for about ten
minutes in a drying oven to a temperature between 100° and
130° C. Like the fixed oils, they are colored brownish or
brownish-black with osmic acid and are intensely colored with
alkannin and cyanin. The volatile oils are also colored a carmine
red with very dilute solutions of fuchsin. Cells containing resins
and terpenes are colored green by the use of aqueous solutions
of copper acetate, the freshly cut twigs or leaves being allowed
to remain in the solution for a few days.

VOLATILE OILS.— The odors which are characteristic of
very many plants are due chiefly to a group of principles known
as volatile oils. They are, for the most part, mixtures of terpenes
and camphors, and are obtained from the plant by distillation
with steam, the oil rising to the surface of the distillate, being
only slightly soluble in water. Volatile oils are readily soluble
in alcohol, ether, chloroform, and in the fixed oils. Some of
them show a tendency to absorb oxygen, and are converted into
resinous substances. They are widely distributed and are char-
acteristic of certain families, viz. : Pinacese, Cruciferae, Labiatae,
Lauracese, Myrtacese, Rutaceae, and Umbelliferae.

232 A TEXT-BOOK OF BOTANY.

With the exception of the seeds, in which they are seldom
found, volatile oils occur in nearly all parts of the plant. They
are formed either as a direct result of the activities of the pro-
toplasm or by reason of changes in some of the constituents of
the cell-wall. In a few instances the volatile oil is formed from
a mother substance, being in the nature of a glucoside, and in this
form occurs in the seeds of the almond and mustard.

BOTANICAL CLASSIFICATION. — The composition of volatile
oils is in many cases very complex ; seldom do they consist of
only one substance, as in turpentine oil. Usually they consist of
a number of chemical compounds, the most complex being
American peppermint oil, from which no less than seventeen
different, well-characterized chemical compounds have been
isolated. As the volatile oils are of considerable economic value,
they have been rather very extensively studied. It remains for
botanists to apply this knowledge to the study of the living plant.
The physiologist will find the study of the origin, transportation,
and localization of volatile oils in different parts of the same
plant of very great interest. Such studies will throw considerable
light upon the entire question of origin and transformation of the
different plant constituents. In many cases, even the constitution
of the constituents in volatile oils has been ascertained, so that
on a sound scientific basis, hypotheses may be developed con-
cerning the complex changes which are possible in the substances
derived from the protoplasm. Again, the distillation products
obtained in the study of volatile oil show that the living plant
may contain such simple compounds as formic alcohol, formalde-
hyde, formic acid, hydrocyanic acid, etc.

Volatile oils which have been carefully studied are obtained
from plants of the following families: Polypodiaceae, Pinaceae,
Pandanaceae, Gramineae, Palmae, Araceae, Liliaceae, Iridaceae, Zingi-
beraceae, Piperaceae, Salicaceae, Myricaceae, Juglandaceae, Betu-
laceae, Moraceae, Aristolochiaceae, Chenopodiaceae, Ranunculaceae,
Magnoliaceae, Anonaceae, Myristicacese, Monimiaceae, Lauraceae,
Cruciferae, Resedaceae, Hamamelidaceae, Rosaceae, Leguminosae,
Geraniaceae, Tropaeolaceae, Erythroxylaceae, Zygophyllaceae,
Rutaceae, Burseraceae, Meliaceae, Polygalaceae, Euphorbiaceae,
Anacardiaceae, Vitaceae, Tiliaceae, Malvaceae, Theaceae, Diptero-

CELL-CONTENTS AND FORMS OF CELLS. 233

carpaceae, Cistaceae, Turneraceae, Lythraceae, Myrtaceae, Aralia-
cese, Umbelliferae, Ericaceae, Primulaceae, Convolvulaceae, Ver-
benaceae, Labiatae, Solanaceae, Caprifoliaceae, Valerianaceae, and
Compositae.

COMPOSITION OF VOLATILE OILS. — The volatile oils are usu-
ally of a very complex composition; it will be found, however,
that they owe their principal characteristics to one or more
definite compounds. The following classes of compounds have
been derived from the volatile oils.

TERPENES, hydrocarbons of the formula C10H16, are found in
the volatile oils of the Pinaceae, Rutaceae, etc. The terpene pinene
makes up practically the entire bulk of turpentine oil. The
terpene limonene is found in the oil of lemon to the extent of
90 per cent. It is not, however, the characteristic constituent in
this oil, the odor of lemon being due to an aldehyde, citral.

SESQUITERPENES, hydrocarbons of the formula C15H24, have
been isolated from a number of oils, the best known representa-
tive of this class being cadinene, occurring in the oils of cubeb,
patchouli, savin, etc.

ALCOHOLS belonging to the aliphatic and aromatic series occur
in a number of oils combined as esters with the fatty acids. Both
methyl alcohol and ethyl alcohol are found in the aqueous dis-
tillates in the preparation of certain oils. This occurrence is
usually explained as being due to the decomposition of other sub-
stances. Methyl alcohol is thought to be derived from the de-
composition of cellulose, while ethyl alcohol is considered to be
a product of the fermentation of carbohydrates. That ethyl
alcohol may be derived in this manner is probable from the obser-
vations of Maze, who obtained alcohol from germinating seeds.
Esters of methyl alcohol, especially methyl salicylate, are widely
distributed. Among other alcohols, the following may be men-
tioned: Linalool constitutes the bulk of lignaloe oil; geraniol, a
diolefinic alcohol makes up the bulk of rose oil ; benzyl alcohol,
as an ester, occurs in the oils of jasmine, tuberose, ylang-ylang,
etc. ; cinnamic alcohol, as an ester, occurs in cassia oil, storax, and
Peru balsam ; menthol (peppermint camphor), a secondary alcohol,
is found in peppermint oil; borneol (camphyl alcohol) occurs

234 A TEXT-BOOK OF BOTANY.

in the oils of valerian and serpentaria, the acetate of this alcohol
being found in many oils of the Pinacese.

ALDEHYDES. — The simplest of the aliphatic aldehydes, for-
maldehyde, has been found in apopin oil, the latter being derived
from an unknown plant growing in Japan. Acetaldehyde is com-
monly present in the distillates of seeds. Citral is found in
lemon oil, giving it its characteristic odor. It is also found in the
oils distilled from the leaves and twigs of the lemon tree, sweet
orange tree, sassafras, etc. Benzaldehyde is formed upon the
hydrolysis of amygdalin.

KETONES. — Of the aliphatic ketones, acetone has been ob-
served, together with hydrocyanic acid, in the distillation of a
number of leaf oils. Carvone occurs in the oil of caraway.
Pulegone occurs in large amounts in European pennyroyal
oil and the oils of other members of the Labiate. Japanese or
laurel camphor is obtained by the distillation of the wood of
Cinnamomum Camphora. Irone, a cyclic ketone, occurs in orris
root.

PHENOLS AND PHENOL ETHERS are found in a number of
volatile oils. Thymol constitutes the larger part of the oil of
ajowan (Ptychotis coptica). Carvacol is a constituent in many
Labiate oils. Anethol is the principal constituent of the oils
of Pinipinella anisatum and Illicium verum and is an important
constituent in the oil of fennel. Eugenol occurs in the oils
of the Myrtacecc and Lauracecc. Apiol is a constituent o<f the
fruit of parsley, and safrol is the principal constituent of
sassafras oil.

ACIDS. — Quite a number of acids are obtained as a by-product
in the aqueous distillation of volatile oils. Among these may be
mentioned formic acid, acetic acid, isovaleric acid, benzoic acid,
cinnamic acid, salicylic acid, etc.

ESTERS give the fragrance to most volatile oils. Some oils
consist almost entirely of esters, as wintergreen oil and birch
oil, which contain methyl salicylate. The latter is probably one
of the most widely distributed of the esters. Linalyl acetate is
the characteristic constituent of bergamot and lavender oils.
Geranyl acetate is found in the oils of lemon grass, neroli,

CELL-CONTENTS AND FORMS OF CELLS. 235

coriander, etc. Esters of benzoic and cinnamic acids are found
in storax, Tolu balsam, and Peru balsam. Bornyl isovalerate
occurs in valerian oil.

LACTONES. — The odoriferous principle known as coumarin is
widely distributed in the plant kingdom. It occurs in some of
the ferns," grasses, tonka bean, " Waldmeister " (Asperula
odorata), etc. It apparently is formed as the result of the action
of a ferment, as it is detected only after the drying of the plant.
Alantolactone is the principal constituent of the oil of Inula
Helenium.

NITROGEN AND SULPHUR COMPOUNDS occur frequently in the
aqueous distillates of plants yielding volatile oils. Hydrocyanic
acid is readily detected by means of Prussian blue, and occurs in
the distillates not only of cyanogenetic plants but in a large num-
ber of others as well. The mustard oils are esters of isothio-
cyanic acid and are characterized by their penetrating odors.
Allyl mustard oil is obtained from the seeds of Sinapis nigra and
a few other plants of the Cruci ferae. (Consult " The Volatile
Oils," Gildemeister and Hoffman, translation by Edward
Kremers; also " Semiannual Reports," by Schimmel & Co.)

FORMATION OF VOLATILE OILS. — The chemical study of
odorous principles shows that they vary considerably in their*
composition. Not much is known regarding the formation of
volatile oils. Charabot and Herbert have suggested that the esters
may originate in the cells containing chloroplastids. They suggest
that under the influence of an enzyme of reversible activity the
esters are formed from the acids and alcohols present in the plant
cell, and that they continue to form until the flowering period.
They are then diffused to other parts of the plant, notably
the inflorescence. While some of the oils are indirect products
connected with photosynthesis, others arise through the decom-
position of a mother substance, as the glucosides, and still others
originate as a metamorphosis of the cell-wall.

PHYSIOLOGICAL ROLE OF OILS. — It is usually considered that
volatile oils occurring in receptacles near the surface of the plant,
as in fruits like the orange, serve to prevent the entrance of
animal and vegetable parasites, and thus prevent disease. Again,
the oils which are found in glandular hairs covering the leaves

236 A TEXT-BOOK OF BOTANY.

and stems of many plants are supposed to be useful in preventing
depredations by animals. The odorous principles which occur in
many flowers are supposed to exert a directive influence upon
insects and thus assist in the work of cross-pollination. While
biologists usually consider the volatile oils as serving ecological
uses yet those investigators, who study the perfume-yielding con-
stituents very closely, are inclined to consider them as being in the
nature of food materials that are used after the fertilization of the
flower and during the development of fruit and seeds.

RESINS, GUM-RESINS AND BALSAMS. — A large number of this
class of plant products are found in commerce and used in medi-
cine and in the arts. A few of these occur as normal products

FIG. 126. Menthol: A, individual crystals obtained by sublimation; B, the commonly
occurring aggregates of very fine needles.

in living plants, as the gum-resins of the Umbelliferse, the gum-
resin euphorbium, and the resins of mastiche and sandarac. Most
of the others arise as a result of wounds in plants and are in the
nature of pathological products, as benzoin, styrax, Tolu balsam,
Peru balsam, etc. Until recently not much was known except in a
general way regarding the composition of resins. Largely through
the researches of Tschirch and his students the nature and the
constitution of the important constituents in a number of the
resins have been worked out. As a result of these studies seven
principal groups of resins are recognized.

I. Tannol Resins. — These are esters of aromatic phenols and

CELL-CONTENTS AND FORMS OF CELLS. 237

behave toward iron salts and some other reagents like tannin.
They are found in relatively large amounts in a number of the
resins and balsams, and occur in rather widely separated families,
as follows : Peru balsam and Tolu balsam obtained from certain
members of the Leguminosae, styrax from the Hamamelidacese,
benzoin from the Styracaceae, aloe from the Liliaceae, dragon's
blood from the Palmae, and the resins from the Umbelliferae, in-
cluding ammoniac, galbanum, asafoetida, etc.

2. Resene Resins. — These are mostly colorless, indifferent
substances occurring in resins and are not only insoluble in
potassium hydroxide but exceedingly resistant to- it, and are not
capable of acetylization. To this group belong the resinous
exudations of the Burseraceae, including myrrh, olibanum, and
elemi; also of the Anacardiaceae, including mastic; and of the
Dipterocarpaceae, including gurjun balsam and dammar.

3. Resinolic Acid Resins. — These are oxy-acids containing
either or both hydroxyl and carboxyl groups. They form color-
less crystals and are either free or combined with alcohol in the
form of esters. They have an acid reaction and are soluble in
solutions of sodium hydroxide, and with difficulty form com-
pounds with acetyl chloride. Acids belonging to this group have
been obtained from a number of the resinous exudations of the
Coniferae, including sandarac, Canada turpentine, and Strass-
burg turpentine. It is also obtained from, a number of resins
which are in the nature of pathological products, as larch turpen-
tine, Jura turpentine, and French turpentine. The abietic acid
in colophony and the succinoabietic acid found in the fossil resin
known as amber, also belong to this class of acids. Furthermore,
resinolic acids are found in the fungus Polyporus officinalis, and
in some of the exudations of the Leguminosae, including the oleo-
resin known as copaiba and the recent- fossil resin, Zanzibar-
copal.

4. Resinol Resins. — Resinols are aromatic alcohols which
usually form colorless crystals and occur either free or in the
form of esters. The principal constituents of guaiac resin belong
to this class, namely, guaiaconresinol (guaiaconic acid),
guaiacresinol (guaiacic acid), and guaiacinresinol (guaiacinic
acid). Resinols are also found in small quantities in other resins.

238 A TEXT-BOOK OF BOTANY.

5. Fatty-resins. — The resins of this class differ from the others
heretofore considered in that they are derivatives of some of the
fatty acids. To this group belongs the resinous exudation known
as " stick-lac," occurring on a number of trees growing in the
East Indies, being caused by the punctures of a hemipterous in-
sect, Coccus lacca.

6. Pigment Resins. — In this group are included those exuda-
tions in which the resins are combined with a chromogenic deriva-
tive. These have been studied but very little, and the best repre-
sentative of this class is gamboge, which is used in medicine as
well as for coloring in art.

7. Glucosidal Resins. — This group includes, as the name
would imply, those resins which are in the nature of glucosides
and yield on hydrolysis glucose as well as some other derivative.
The resins found in jalap, scammony, and other plants of the
Convolvulaceae belong to this group. (Consult A. Tschirch, " Die
Harze und die Harzbehalter.")

ORIGIN OF RESINS. — It was at one time considered that the
resins were derivatives of tannin. Now that Tschirch has shown
that there are a class of resinous substances that give reactions
for tannin, it might seem that this theory would receive additional
support. However, as he himself explains, the resinotannols con-
tain a great deal more carbon than the tannins. Furthermore,
Tschirch has shown that a number of the constituents of the
resins give color reactions with Liebermann's reagent for phy-
tosterol. On the other hand, a number of these same constituents
do not give the characteristic color reaction for phytosterol with
Salkowsky-hesse's reagent. With regard to the resins of the
resinolic acid series, Tschirch concludes that they are probably
not derived from volatile oils, but that they are derivatives of a
common mother substance. In a later publication Tschirch
(" Chemie und Biologic der Pflanzlichen Sekrete ") states that in
all probability all the secretory products, formed as a meta-
morphosis or decomposition of the resinogenous lamellae, are the
direct products of ferments accompanying these layers.

LATEX OR MILK- JUICE is the product formed in special secre-
tory organs in the plant, and exudes readily on even very slight
injury of the plant. Under the microscope it is seen to be in

CELL-CONTENTS AND FORMS OF CELLS. 239

the nature of an emulsion, consisting of small globules, varying
from 0.0005 to 0.005 mm. in diameter. It is of variable com-
position and may contain certain hydrocarbons, as in pure
caoutchouc and pure gutta percha, oils, resins, mucilage, starch,
calcium oxalate, and alkaloids.

Latex is found in three distinct types of tissues, differing

FIG. 127. Study of Latex: A, tangential-longitudinal section through root of Taraxa-
cum, showing laticiferous vessel (m), sieve tube (s), parenchyma (p). B, the bark of
Euonymus, fractured and showing the thread-like latex (c) between the pieces (b). C, the
fragments of thread-like latex of Euonymus viewed under the microscope, and distinguished
from fibers by their dissolving in chloroform. — A, after Meyer; C, from drawing by Hogstad.

from each other in origin and manner of development, i. Laticif-
erous cells are long, tubular cells which arise in the initial cells
of the embryo and continue to elongate, keeping pace with the
growth of the plant, branching and traversing all of its organs.
They may extend through the cells of the pith, bast, and primary
cortex, run along the veins of the leaf, being found occasionally
in the mesophyll, and extend into the fruit. Cells of this kind

240

A TEXT-BOOK OF BOTANY.

are present in the Apocynaceae, Asclepiadaceae, Euphorbiaceae,
Moraceae, and Urticaceae. 2. Laticiferous vessels are long tubes
resembling the latex cells, but are formed by the absorption of the
transverse walls in the superimposed cells. They develop very
early, the cell-fusions taking place, in some instances, in the
primary meristems. They may be either simple or branching, the
branches connecting with other tubes and forming a net-work.
These anastomosing tubes can be separated readily from the sur-

ooo

00

FIG. 128. Microscopical appearance of latex in Ficus elastica, showing small globules
and sphere-crystals which separate soon after the removal of the fresh latex. — From a draw-
ing by Hogstad.

rounding tissues by boiling the material with dilute solutions of
potassium hydroxide. The laticiferous vessels usually occur as-
sociated with the leptome, although they may be found in other
tissues of the axis and leaf. Milk vessels are found in the fol-
lowing families : Araceae, Campanulaceae, Compositae, Convol-
vulaceae, Euphorbiaceae, Geraniaceae, Musaceae, Oleaceae, and
Papaveraceae. 3. Secretory cells resembling laticiferous cells,
in that they have a latex-like content, although probably of
secondary origin, have been found in the Celastraceae, Oleaceae,

CELL-CONTENTS AND FORMS OF CELLS. 241

Tiliacese, and Urticacese. The secretion in these cells is some-
times visible even with the naked eye, and it is possible, on break-
ing the bark, to obtain the latex in the form of delicate, elastic
threads. These caoutchouc threads may be readily seen on break-
ing the bark of euonymus, and may be distinguished from bast-
fibers by their readily dissolving in chloroform (Fig. 127).

The milk-juice varies in color in different plants, being color-
less, as in oleander ; whitish, as in the Apocynaceae and Asclepiada-
ceae; or yellowish, as in chelidonium, or orange-red, as in
sanguinaria. The latex of a number of plants is collected to form
a number of commercial products. Opium is the dried milk-juice
obtained from the capsules of Papaver somniferum. Lactucarium
is the dried milk-juice of Lactuca virosa and other species of
Lactuca. Elastica or India rubber is the prepared milk- juice ob-i
tained from a number of plants, the most important being the
Brazilian or Para rubber tree (Hevea brasiliensis) , the Central
American rubber tree (Castilloa elastica), the East Indian rubber
tree (Ficus elastica), and the rubber vines of Africa (Landolphia
species). Gutta percha is the concrete juice of Palaquium Gutta
(Fam. Sapotaceae).

ENZYMES OR FERMENTS. — In connection with the growth of
the plant, there occurs a constant change in the substances which
comprise it. These changes are brought about largely through
the influence of a class of substances known as enzymes. Atten-
tion has been directed to the decomposition of starch with the
formation of sugar. This change is brought about by the secre-
tion in the protoplasm of an enzyme called amylase (diastase).
It is produced in the living cell, can be extracted from the plant,
and will produce the same effect upon starch grains which have
been separated from the cells.

One of the interesting properties of the ferments is that in'
comparison with the amount of ferment employed the product
formed through its influence is very large. Thus it is stated that
amylase is able to hydrolyze 10,000 times its own bulk of starch.
Results of this kind are considered to be due to catalytic action
of the ferments, i.e., their power of inducing chemical reactions
by their mere presence without themselves entering into the
products formed. The ferments require specific temperatures for
16

242 A TEXT-BOOK OF BOTANY.

their action, as, for example, emulsin or sinaptase, which decom-
poses a number of the glucosides at a temperature of 35° to 40°
C., while amylase, the ferment of germinating seeds, requires a
somewhat higher temperature, namely, 50° to 70° C.

Another property of these ferments, which is generally re-
garded as characteristic of them, is that of becoming inactive when
solutions are heated to a temperature of 100° C. Nothing is
known with regard to the composition and constitution of the
ferments, and they are usually classified according to the class
of substances which they decompose. Thus, amylases act upon
starch grains with the formation of sugar; proteinases break
down the true proteins, etc.

The following is an enumeration ot the principal plant
enzymes, together with their occurrence and some of their
properties :

AMYLASE. — The ferment acting upon starch in germinating
barley, with the formation of glucose and maltose, was separated
by Payen and Persoz in 1833, and called " diastase." This fer-
ment occurs, probably, in all parts of all green plants, and is
especially abundant in all cells where starch is formed OT stored.
It is found in large amounts in various cereal grains, and also
occurs in the fungi, yeasts, and bacteria. Recent investigation
seems to show that in the cells with reserve starches there are two
different kinds of diastatic enzymes, the one acting on the soluble
starch, called amylase, and the other acting on the insoluble
starch or amylopectin, and called amylopectinase.

INULINASE is the ferment found in the cells of plants contain-
ing inulin. It decomposes the latter, changing it into fruit sugar
or fructose. Inulinase has no effect upon starch. It has been
found in the Composite and also in Aspergillus, Penicillium,
and a number of genera of the Eumycetes.

MALTASE (a-glucosidase) is always associated with the
diastases, and from which it has not been separated. It is widely
found in the vegetable kingdom, and is especially abundant in
malt and some of the yeasts.

INVERTASE (a-fructosidase), sometimes also spoken of as in-
vertin or sucrose, has the property of converting cane sugar into
invert sugar (a mixture of glucose and fructose). It is found in

CELL-CONTENTS AND FORMS OF CELLS. 243

wheat and barley, dates, bananas, mulberries, and especially in
the green leaves and young shoots of higher plants. In yeast it
is accompanied in many cases by maltase.

EMULSINS are a class of glucoside-resolving enzymes found
in the seeds of the almond, the bark of Prunus serotina, the leaves
of Prunus Laurocerasus, and in a large number of plants of the
Rosacese. It is also found in the tuberous roots of Manihot
utilissima, Monotropa, species of Polygala, Hedera Helix.
Enzymes resembling emulsins, and capable of attacking gluco-
sides, have been detected also in Aspergillus, several species of
Polyporus, found growing in wood, lichens, mosses, and bacteria.
A distinction is sometimes made between almond-emulsin, Asper-
gillus-emulsin, etc.

MYROSIN, an enzyme which hydrolyzes the sulphur-glucosides,
occurs in the Cruci ferae and in certain species o-f Manihot. It is
localized in the seeds of cells which are rich in proteins. Its
presence may also be demonstrated in the mesophyll of young
leaves, in the pericycle of stems, and in the cork-cells of roots.

GAULTHERASE (Betulase), an enzyme which hydrolyzes the
glucoside of methyl salicylate called " Gaultherin." This is
present in Gaultheria and many other of the Ericaceae. It is
probably very widely distributed in the vegetable kingdom. (See
Amer. Jour. Pharm., 1898, p. 412.)

PECTASE AND PECTINASE. — The name Pectase is applied to an
enzyme that is always present in ripening fruit, and is capable
of converting pectose, a product insoluble in water, into a soluble
substance called pectin. The latter can be further decomposed
into a number of closely related substances, known as pectinic
acids, and which are usually combined with calcium. The term
PECTINASE is applied to the enzymes which in the presence of
lime coagulates the juices containing the dissolved pectinous sub-
stances forming the so-called fruit jellies. This reaction is con-
ditioned on the presence of lime and a certain equilibrium being
established between the enzyme and the concentrations of the acid
and calcium salts. Pectose originates by reason of certain changes
in the lamellae of cell-walls. While it occurs in appreciable quan-
tities in those fruits that have the properties of producing jelly,
it is probably very widely distributed.

244 A TEXT-BOOK OF BOTANY.

CYTASES (cellulases) is the name applied to those enzymes
which are capable of dissolving cellulose. An enzyme of this
character is located in the aleurone layer and in the epithelium of
the scutellum in the germinating grain of barley. It is also found
in the endosperm of the date palm, the cytase being formed in
the embryo and the dissolved products being used up as food.
Enzymes of this character are also found in wood-destroying
fungi and bacteria.

PROTEIN ASES (carbamases) is the name applied to those
enzymes which break down the true proteins or carbamide deriva-
tives. They are always accompanied in the plant cells by other
ferments, and occur especially in seeds, being more abundant in
those containing oil than starch, as hemp, mustard, castor oil,
and flaxseed. They are also found in certain fleshy fruits, as
figs and pineapple; succulent leaves, as Agave, and in insectivo-
rous plants. In the fruit and other parts of the papaw tree ( Carica
Papaya} occurs a proteolytic enzyme, called Papain, which readily
digests fibrin, thus behaving like trypsin, a ferment in the pan-
creatic juice. A similar ferment, called Bromelin, has been ex-
tracted from the fleshy pulp of the pineapple. Ferments like
Papain and Bromelin are naturally of very great interest, as they
behave like the animal ferments, pepsin and trypsin. The Papain
of commerce seems to be of varying composition, and unless ob-
tained from authentic sources is not reliable.

CHYMASES OR ENZYMES which effect the clotting of milk.
The coagulating action of the fig (Ficus Carica} was known to the
ancients. This action has been shown by Chodat and Rouge to
be due to a vegetable chymase and called by them " sykochymase."
A large number of plants possess the property of rendering milk
ropy. Of these the following may be mentioned : Ranunculus
bulbosus, Capsella Bursa-pastoris, Plantago lanceolata, Medicago
lupulina, Pinguicula vulgaris, Artichokes, etc. An enzyme of this
character has also been found in germinating seeds of Ricinus
communis, Pisum, Datura, etc., and some of the fungi.

ZYMASE, an enzyme causing the decomposition of glucose with
the formation of alcohol and carbon dioxide. This decomposition,
known as alcoholic fermentation, is considerably less simple than
was formerly supposed, a number of enzymes and subsidiary sub-

CELL-CONTENTS AND FORMS OF CELLS. 245

stances taking part in the reaction. Zymases are widely dis-
tributed throughout the entire plant kingdom, and occur in
greatest amounts in yeasts and other organisms which induce
alcoholic fermentation. The enzyme, which causes the transfor-
mation of glucose into lactic acid and is secreted by lactic acid
bacteria, has been given the name of " lactic acid bacteria-zymase."

OXYDASES is the name applied to those enzymes in which the
decomposition or reaction involves an oxidation. Several kinds
of oxydases are recognized, depending upon the nature of
the original substance that is broken down. ( i ) Alcoholase, the
enzyme of acetic bacteria which oxidize ethyl alcohol to acetic
acid. (2) Phenolases include the laccases, the oxidizing enzymes
found in the lac-tree (Rhus succedanea), and in some other
plants. The black lacquer covering the beautiful Japanese vases
and boxes, and which is the most indestructible varnish known to
man, is formed by an oxidizing enzyme acting on the phenolic
resins of the lac-tree.

Catalases in their chemical action resemble some of the col-
loidal metals, in that they are able to decompose hydrogen
peroxide with the liberation of oxygen. Enzymes of this char-
acter have been found in virtually all plant juices. Catalases are
of two kinds, one soluble in water, occurring in the seeds of apple
and peach, and an insoluble form found in the leaves of clover,
rose, and spruce. Highly active catalases are also obtained from
fungi, yeasts, and bacteria.

While some of the vegetable ferments have been isolated and
are prepared on a commercial scale, as diastase and the peptic
enzyme papain found in the latex of Carica Papaya, in other
cases the ferment-producing organisms themselves are used in
a number of industries involving fermentation processes, as the
yeast-plants and certain of the molds and bacteria.

The microchemical study of the ferments is attended with cer-
tain difficulty on account of the lack of specific reagents for their
detection. The most that can be done is to study the products
formed by their action upon certain other constituents of the cell.
(Consult " General Chemistry of the Enzymes," by Hans Euler,
translation by Thomas H. Pope.)

246

A TEXT-BOOK OF BOTANY.
EXAMINATION OF CELL-CONTENTS

PROTOPLASMIC

NON-PROTOPLASMIC

Crystalline

Crystalloidal

Amorphous

i. Cytoplasm
2. Nucleus
3. Plastids

4. Calcium oxalate
5. Sugars
6. Alkaloids
7. Glucosides
8. Phyto-globulins

9. Starch
10. Inulin

ii. Mucilage
12. Tannin
13. Resin
14. Oil
15. Latex
1 6. Calcium carbonate

i, 2, and 3 have characteristic appearance (see Frontispiece).
4. Crystals of characteristic forms, soluble in hydrochloric acid
and insoluble in acetic acid. 5. Crystalline in fresh material
treated with alcohol. The glucoses give a reddish precipitate with
Fehling's solution. 6. Piperine separates in definite crystals in
the plant cell ; the alkaloids of hydrastis form crystallizable salts
with sulphuric or nitric acids ; the alkaloids in hydrastis, ipecac,
coffee, tea, and guarana yield crystalline sublimates. 7. Concen-
trated sulphuric acid gives with strophanthin a bright green color.
8. Phyto-globulins form definite crystals (see paragraph on
aleurone grains). 9. Blue with dilute iodine solution, except the
amylo-dextrin starches, as mace, which are colored red. 10.
Sphero-crystals in fresh material treated with alcohol, n. Colored
blue with alcoholic solutions of methylene blue. 12. Reddish-
brown with copper acetate solutions. 13. Terpene resins are
colored green with copper acetate solutions. 14. Separation in
the form of large globules on the application of sulphuric acid or
solution of hydrated chloral. The volatile oils are more soluble in
alcohol than fixed oils, the latter being completely removed from
the cells by the use of ether or other similar solvent. 15. Latex
occurs as an emulsion consisting of numerous globules. 16.
Calcium carbonate dissolves with an effervescence on the addi-
tion of hydrochloric acid or acetic acid.

Factors Influencing Growth. — Plants have certain inherent
or inherited tendencies or characters which make up the inner
constitution, arid this cannot be modified by external agencies
except within more or less narrow limits. Depending upon this
character we find plants as different in kind as the apple tree
and pine growing under precisely the same conditions. In other

CELL-CONTENTS AND FORMS OF CELLS. 247

words, the character of the structure is determined in the main
by the nature of the organism. It is true that an apple tree may
grow better in one locality than another, but it is still an apple
tree whether it be dwarfed or attain to the full measure of its
growth. These slight changes in the character are known as
accidental variations. Frequently they are the result of tempo-
rary conditions and are not repeated in the succeeding genera-
tion. On the other hand, if the special conditions remain these
individual variations may be repeated in generation after gen-
eration and finally become permanent characters.

The gradual change in the structure and nature of organisms
which takes place through long periods of time is spoken of as
EVOLUTION. In some cases specific changes in the characters of
plants arise rather suddenly without any known cause, and such
changes are spoken of as saltations or MUTATIONS.

The factors essential for growth in all cases are food, water,
and a certain temperature. Among the food elements we may
mention as of chief importance, carbon, hydrogen, oxygen, and
nitrogen. Some of the other elements are also essential to most
plants, although they occur in relatively small proportion in the
plant, as potassium, magnesium, phosphorus, sulphur, iron, and
calcium. The latter element does not seem to be necessary to
the normal development of some of the Fungi and certain Algse.

Water permeates all parts of the plant, and when the cells
are in the normal turgescent state it contains more than half
its weight of water. When the supply of water falls below the
normal the plants begin to droop and finally die. The need of
plants varies greatly in this particular ; some are aquatic in their
habits and live wholly in the water; others can live only on the
land ; and still others are adapted to desert regions.

The degree of temperature necessary for growth varies within
certain limits for each kind of plant, but, as is stated by Pfeffer,
the greatest extremes are shown by Fungi, Bacteria, and the
lower Algse. Generally speaking, the most favorable temperature
for growth is between 24° and 34° C.

Besides the factors enumerated there are other factors which
influence growth. They include light, gravity, mechanical
agencies, etc., and are sometimes spoken of as external stimuli.

248 A TEXT-BOOK OF BOTANY.

It is difficult to separate those factors which act solely as
external stimuli from those which are essential to the normal
growth of the plant and which may be considered as physiological
factors. For example, light under certain conditions may be
regarded as in the nature of an external stimulus and not essen-
tial to the growth of the plant, while in other cases it has a direct
influence on normal growth and is essential to the life of the
plant, as in all plants or parts of plants where photosynthesis
takes place.

In addition to the essential food elements, there are many
substances which affect the growth of plants which may be
grouped as chemical stimuli, such as (a) the substances secreted
by gall-forming insects, (b) in a certain measure some of the
substances produced by Fungi, (c) and numerous substances not
found as normal constituents of the plant. Depending upon the
amount of the substance present and the conditions under which
it is supplied, the substance may act as a poison and injure the
plant, or it may accelerate growth, or cause abnormal develop-
ment.

This subject has an important bearing on the physiological
testing of drugs. Robert states that in determining the qualities
of a new chemical, preliminary experiments should be conducted
on lower plants and animals before trying it on man. Of the
plants which have been used in the testing of poisons the follow-
ing may be mentioned : Oscillaria, Spirulina, Nostoc, Zygnema,
Spirogyra, Saccharomyces, Mucor, Elodea, Lemna, Pistia,
Potamogeton, Myriophyllum, Ceratophyllum, Tradescantia, seed-
lings of grasses, lupine, bean, pea, corn, etc. Kraemer has em-
ployed seedlings of Lupinus albus and Pisum sativum in testing
solutions containing ethyl alcohol, strychnine nitrate, brucine
sulphate, and tincture of nux vomica (Amer. Jour. Pharm.,
1900, p. 472).

FOOD OF PLANTS. — It has already been pointed out that certain
of the chemical elements are necessary for the growth of plants,
and that these are derived partly from the surrounding atmos-
phere and partly from the soil. Those elements derived from
the air are either themselves gases or exist in combination in the
form of gas, and include oxygen, nitrogen in exceptional cases,

CELL-CONTENTS AND FORMS OF CELLS. 249

and carbon dioxide, the source of the carbon entering into the
carbon compounds formed by plants.

The elements obtained by plants from the soil exist in com-
bination with other elements and must be in the form of solution
to be absorbed. The soil consists largely of mineral substances,
together with certain organic products (humus). The water held
in the soil not only acts as a medium for carrying the soluble
constituents in the soil to the plant, but is itself an important food
product, being the source of the hydrogen used by plants, as also
of assimilable oxygen. Among the mineral constituents of the
soil that are useful to plants are ammonium salts and nitrates,
sulphates, phosphates, chlorides, silicates, and carbonates. When
plants are collected and subjected to a temperature of about 110°
C. the water is driven off, and then if heat sufficient to incinerate
the material is applied the organic matter is driven off in the
form of gases, leaving the mineral constituents in the form of
ash, as calcium, magnesium, iron, potassium, sodium, and a few
other elements.

FORMATION OF LEAFMOLD. — When the leaves of a tree fall to
the ground they begin to decay and ultimately they are dis-
integrated, and their substances become incorporated with the
other elements of the soil. The same thing happens with the
leaves, stems, and roots of herbaceous plants. Such organic
matter is one of the chief sources of food for plants, and its
presence in the soil is therefore of fundamental importance in the
maintenance of the vegetable mantle of the earth. Coville (Jour.
Wash. Acad. Sci., 1913, p. 79) determined the rate in decomposi-
tion of leaves and used silver maple, sugar maple, red oak, and
Virginia pine. These were exposed to the weather in barrels
and in concrete pits. In one experiment a mass of trodden silver
maple leaves two feet in depth, with an initial acidity of 0.92
normal, was reduced in a single year to a three-inch layer of
black mold containing only a few fragments of leaf skeletons
and giving an alkaline reaction. Sugar maple leaves have shown
a slower rate of decomposition than those of silver maple, while
red oak leaves still showed an acidity of o.oio normal after three
years' exposure, and leaves of Virginia pine an acidity of 0.055
normal under the same conditions. During the decomposition of

250 A TEXT-BOOK OF BOTANY.

leaves the acid substances are decomposed and to some extent
dissipated in the form of gases.

The chief agents in the decay of leaves are fungi and bacteria.
A number of forms of animal life also contribute greatly to the
decay also, as earthworms, larvae, flies and beetles and myriapods
or thousand-legged worms. Coville distinguishes two kinds of
leaf mold : (a) In which the leaves show a condition of imperfect
decomposition, due to the development and maintenance of an
acid condition, which is inimical to the growth of microorganisms
of decay. Because of the resemblance of this mat or turf to bog
peat in appearance, structure, and chemical composition, and be-
cause it supports a type of vegetation similar to that of bog peat,
it has been named UPLAND PEAT. This is characteristic of the
sandy pine and oak woods, where grow huckleberries, laurel,
princess bine, pink lady's slipper, trailing arbutus, etc. (b) The
other is characteristic of the black mellow mold made up of com-
pletely rotted leaves, the acidity being neutralized in part by the
calcium present in the leaves and partly by the underlying soil,
which is usually of a calcareous nature. This is characteristic of
forests of tulip poplar, ash, and oaks, in which grow sanguinaria,
caulophyllum, hydrastis, trillium, etc.

ORGANIC CONSTITUENTS IN SOIL. — During the past few years
Schreiner and his associates in the Bureau of Soils, U. S. Depart-
ment of Agriculture, have isolated and identified a number of
soil constituents. They have found that certain of these con-
stituents, as dihydroxystearic acid, are rather characteristic of
poor soils, and that the effect of fertilizers on such soils was to
increase their fertility by neutralizing their toxic constituents
rather than by the addition of any food constituents to the soil.
The compounds isolated by them have varied considerably, and
may be grouped into the following classes : i , Paraffin hydro-
carbons, represented by hentriacontane ; 2, hydroxy- fatty acids,
represented by a-monohydroxystearic acid and dihydroxy-
stearic acid ; 3, organic acids of unknown constitution, represented
by agroceric acid, paraffinic acid, lignoceric acid, and a number of
resin acids ; 4, esters and alcohols, represented by agrosterol, phy-
tosterol, glycerides of fatty acids, and resin esters ; 5, carbohy-
drates, represented by pentosans and pentose sugars ; 6, hexone

CELL-CONTENTS AND FORMS OF CELLS. 251

bases, represented by histidine and arginine ; 7, pyrimidine deriva-
tives, represented by cytosine ; 8, purine bases, represented by
xanthine and hypoxanthine ; 9, pyridine derivatives, represented
by picoline carboxylic acid.

ROOT ABSORPTION. — Notwithstanding the various agents
which are at work tending to break down and dissolve the sub-
stances contained in the soil, as soil bacteria, the liquids given to
the soil by the roots of the plants themselves, the presence of the
so-called humic acids, and the action of water and air, it has been
shown that the soil water is an exceedingly weak solution. This
is largely due to the peculiar absorptive and fixing power of the
soil itself.

The dilution of the aqueous solution of the soil constituents
is a matter of very great significance, for upon this depends its
absorption by the root hairs. While other parts of roots have cer-
tain absorptive powers, the root hairs have been defined as the
organs of absorption of the plant. They are very delicate in
structure and contain protoplasm. Their absorbent function de-
pends upon the principle that when a membrane (animal or
vegetable) is interposed between two liquids of unequal density,
the less dense liquid will pass through the membrane and mix
with the denser liquid. This process is known as OSMOSIS, and
when a liquid passes outward through a membrane or cell-wall
it is called exosmosis, and when inward it is called endosmosis.
The soil is made up of minute earth particles, each of which is
surrounded by a thin film or envelope of water, and it is this por-
tion of the soil liquid that is absorbed by the root hairs. The root
hairs come into close contact with these soil particles ; in fact,
appear to grow fast to them, and the cell-liquid in the root hairs
being denser than that surrounding the soil particles, the latter
passes through the wall into the root hairs.

If, on the other hand, the water supplied to the roots of plants
should contain an excess of soluble material, the plant will be
injured. In this case exosmosis ensues and the plant loses some
of its own liquids or cell-sap and will show signs of wilting. It
is well known that if cultivated plants are supplied with strong
solutions of fertilizer the plants will be injured rather than
benefited.

252 A TEXT-BOOK OF BOTANY.

ROOT PRESSURE. — The distribution of the water absorbed by
the roots to other parts of the plant is influenced by a number of
factors, which are commonly spoken of together as root pressure.
Among these are osmosis within the plant, due to unequal density
of the liquids in different cells; the changes in the equilibrium of
the cell-liquids, due to chemical changes; and the transpiration
of water from the leaves, thus establishing a flow of liquids from
the roots upward, which is usually spoken of as the ASCENT OF
SAP. The cell-sap passes upward through the xylem for the most
part, carrying constituents obtained from the soil to the growing
parts, where they are combined with the products of photosyn-
thesis, and through a series of reactions protoplasm is finally
built up.

OXIDATION. — The free oxygen taken in by plants through the
stomata and lenticels serves the same purpose in plants as that
inhaled by animals, namely, the oxidation of certain compounds,
whereby part of the energy necessary for vital activity is lib-
erated. Oxygen is required by all parts of the plant. When the
roots of plants, such as those of Zea Mays, are surrounded by
water so as to exclude the air the plants will become yellow.
Germinating seeds consume a large amount of oxygen, but not
all the energy formed is used by the plantlet, much of it escaping
as heat, as in the germination of barley in the preparation of malt.
Those plants dependent upon the presence of free atmospheric
oxygen are called AEROBES, while those which are not thus de-
pendent, as certain fungi and bacteria, are called ANAEROBES.

METABOLISM. — Processes of construction and destruction are
going on simultaneously in the plant, and these are all grouped
under the general name of metabolism. The processes whereby
complex substances are built up from simpler ones, as in photo-
synthesis, are together spoken of as CONSTRUCTIVE METABOLISM
(anabolism), while those which involve the breaking down of
complex compounds into simpler ones, either through oxidation
or other chemical action, as when sugar is changed into carbon
dioxide and water, are grouped under the head of DESTRUCTIVE
METABOLISM (catabolism) .

Inasmuch as the carbon dioxide of the atmosphere and the
water taken up by the roots together with the mineral salts which

CELL-CONTENTS AND FORMS OF CELLS. 253

it holds in solution are the only sources of the food supply of
green plants, it follows that the highly complex proteins trace
their origin to these comparatively simple substances. By some
it is supposed that the final stages in the building up or synthesis
of the proteins take place in the leaves, but it is probable that they
take place in all the growing parts of the plant. It has already
been stated in the paragraph on proteins that seeds contain re-
serve materials which are broken up into simpler compounds
through the action of certain enzymes, and thus made available
for the seedling. It is claimed that these compounds are prin-
cipally amino acids, and that of these aspartic and glutaminic acids
occur in largest amount and that these two acids are found in
different relative amounts in different plants. It is furthermore
claimed by some authors that by certain syntheses these com-
pounds are respectively converted into asparagin and glutamin,
both of which occur as reserve materials in seeds and in other
parts of plants as well. Yet other syntheses take place whereby
asparagin and similar bodies are converted into albumin and other
proteins. In the Coniferse the part played by asparagin and
glutamin in protein syntheses is taken by arginin, which substance
is found in considerable amount in the seeds of the plants of this
group.

GROWING POINTS AND MERISTEMS. — Plants are distinguished,
for the most part, by having distinct growing points, known as
vegetative points. These occur at the apex of shoots and roots and
at definite lateral points, being in the stem near the surface and
in roots beneath the endodermis. The walls of the cells in these
regions are very thin and consist almost entirely of cellulose.
The cells are compactly arranged and are more or less polygonal
Or somewhat elongated. They are rich in protoplasm, capable of
rapid division, and constitute the tissue known as PRIMARY MERI-
STEM. In the root three kinds of primary meristem (Fig. 132)
are distinguished: (i) The PLEROME (m, f, g), an axial meri-
stem, which gives rise to the central cylinder or stele; (2) the
PERIBLEM (x, r), or meristematic tissue, which gives rise to the
primary cortex; and (3) the DERMATOGEN (e), from which the
epidermis is developed. In addition to these three meristematic
zones there is at the apex, lying next to the dermatogen, a meri-

254 A TEXT-BOOK OF BOTANY.

stematic group of cells which give rise to the root-cap, known as

the CALYTROGEN (s).

At the growing point of the stem three meristematic zones are
also distinguished, namely, plerome, periblem, and dermatogen.
They are not, however, so well marked as in the case of roots.

The tissues which are developed from the primary meristems
constitute the PRIMARY STRUCTURE. With the growth in thickness
of the stems and roots of Dicotyledons other meristematic cells,
known as SECONDARY MERISTEMS, arise. These are of two kinds :
( i ) One which gives rise to the xylem and phloem, known as the
CAMBIUM, and (2) another which gives rise to the cork, known as
PHELLOGEN. The tissues formed from the secondary meristems
constitute the SECONDARY STRUCTURE of older dicotyledonous
stems and roots.

While the point of vegetation in the higher plants (spermo-
phytes) embraces a number of cells, in the lower plants the tissues
can be traced back to a single APICAL CELL.

CELL- WALL. — Origin and Composition.— It is formed by the
protoplasm, and varies in composition at different stages of the
growth of the cell, and according to the various functions it has
to perform.

In order to thoroughly understand the nature and composi-
tion of the cell-wall, it is necessary to study the origin and forma-
tion of new cells. Growth of the plant is attended not only by
an increase in the size of the cells, but by their division (Fig. 85)
new cells are also formed. Cells that have the property to divide
and form new cells are known as meristematic cells and constitute
the MERISTEM. The new and dividing walls resulting from the
division of the cells consist of a number of substances. When a
cell divides, the two daughter protoplasts which result from the
division of the nucleus and cytoplasm are separated by the forma-
tion of a new wall between them (Fig. 85). The first layer
formed is apparently different from the subsequent layers and is
known as the middle plate or MIDDLE LAMELLA. This layer is
soluble in, or readily attacked by, solutions of the alkalies or solu-
tions containing free chlorine. It is insoluble in sulphuric acid,
and readily stained by the aniline dyes. . While usually more or
less permanent, this middle plate may be finally absorbed, as in

CELL-CONTENTS AND FORMS OF CELLS. 255

the glandular hairs of kamala, or it may be changed into mucilage,
as in chondrus, or transformed into pectin compounds, as in fleshy
roots and fruits.

To this middle plate is added on either side by the newly
formed protoplasts a layer of substance closely resembling cellu-
lose, this constituting the PRIMARY MEMBRANE or primary lamella.

As the cells become older the wall increases in thickness
through the addition of other layers, much in the same manner as
the starch grain increases in size. These subsequent layers are
known as SECONDARY LAMELLA. In a few cells the secondary
lamellae may consist of pure cellulose. As a rule, however, the
wall is rather complex and consists of alternate layers of cellulose
with other substances. Some of these, as mucilage, may be a
simple modification of cellulose, others may consist of cellulose
in combination with other substances, as in the ligno-cellulose walls
of stone cells, or the walls may consist of cellulose and suberin as
in cork cells, or of cutin-cellulose as in epidermal cells. Again,
there may be, through the action of special enzymes, a decomposi-
tion of the cellulose, resulting in the formation of oils, resin, and
wax. Furthermore, it would not seem improbable that some of
the secondary substances in the wall are direct products of the
protoplasm and secreted in the cell-wall, as silica and calcium
oxalate in epidermal cells. The substance called pectin originates
as a modification of the intercellular substance, and is peculiar
to some fruits.

As showing, to some extent, the complexity of the lamellae
in the cell-wall, the following modifications of the wall in secretion
cells may be given: i. The entire outer cell- wall may consist of
a thin layer of suberized lamellae, beneath which is a secondary
mucilaginous layer that develps the secretion, e.g., Hedychium
Gardnerianum. 2. The outer lamellae of the cell-wall may con-
sist of suberin; beneath this is a cellulose lamellae, which only
after treatment with a solution of potassium hydroxide is colored
blue with chlor-zinc iodide; this is followed by a mucilaginous
layer, e.g., Laurus nobilis, Curcuma Zedoaria, Cinnamomum Cas-
sia, Zingiber officinale, Acorus Calamus. 3. The outer layer may
consist of cork, beneath which is a cellulose layer that is colored
blue upon treatment with chlor-zinc iodide without the previous

256 A TEXT-BOOK OF BOTANY.

use of potassium hydroxide ; to this is then added a mucilagino-us
layer, as in the secretion cells of Valeriana officinalis and Magnolia
grandiflora. 4. The outer layer may be suberized, but the cellulose
layer beneath this is not colored blue until the walls have been
first treated with Schultze's solution ; this then is followed by a
mucilaginous layer, e.g., Piper nigrum, Piper Cubeba, and Sassa-
fras officinale. 5. The outer and inner layers may be suberized,
and between these are fine lamellae of cellulose, e.g., Croton
Eluteria. 6. The outer layer may be suberized, beneath which is
a layer of lignocellulose, followed by a mucilaginous layer, e.g.,
Caly can-thus floridus. 7. The outer layer may be colored yellow
with chlor-zinc iodide and dissolves in sulphuric acid, while the
inner layer is suberized, e.g., fruit of Conium maculatum.

CELLULOSE in its various modifications constitutes the greater
proportion of the cell-wall. The cellulose making up the cotton
fiber may be said to be the typical cellulose, and is known as
" cotton cellulose." It is soluble in copper ammonium sulphate
solution ; is colored blue with chlor-zinc-iodide solution or iodine
and sulphuric acid, and is stained by acid phenolic dyes, as alizarin,
if previously treated with basic mordants, as basic salts of
aluminum, etc.

The following solutions are used in the testing of mixed
fabrics containing cotton : • i. A solution of I part of zinc chloride
in 2 parts of hydrochloric acid will dissolve cellulose in about
one-half minute. 2. Upon heating a piece of fabric in a saturated
solution of aluminum chloride, the cotton becomes friable, the
wool remaining unaffected.

According to their origin in the plant, or their behavior toward
reagents, the cellulose walls may be divided into the following
groups: (i) Lignocellulose walls; (2) protective cellulose walls;
(3) reserve cellulose walls; (4) mucilage cellulose walls, and (5)
mineral cellulose walls.

Lignocellulose walls are composed of true cellulose and a
non-cellulose (the 'so-called lignin or lignone), these constituting
the woody (so-called lignified) portion of plants and, in some
instances, also the bast portion of the bark. The lignocelluloses
are colored yellow with chlor-zinc iodide, or iodine and sulphuric
acid. On account of their containing in some instances furfurol,

CELL-CONTENTS AND FORMS OF CELLS. 257

coniferin, vanillin, cinnamic aldehyde, benzaldehyde or other alde-
hydic substances, they give definite color-reactions with certain
reagents. They are also stained by the aniline dyes, as fuchsin,
saf ranin, gentian violet, aniline blue, methylene blue, etc.

Aniline hydrochloride with hydrochloric acid and aniline sul-
phate with sulphuric acid produce a golden-yellow color in cell-
walls containing lignocelluloses.

A 2 per cent, phloroglucin solution, used in conjunction with
hydrochloric acid, gives a reddish-violet color with the lignocellu-
loses, although there are some celluloses of this class which do not
respond to this test, as flax (the bast fibers of Linum). In other
plants phloroglucin may occur as a constituent of the cells.

Hartwich and Winckel (Arch. d. Pharin., 1904, p. 462) have
shown that the red coloration formed upon the addition of vanillin
and hydrochloric acid to phloroglucin is also produced by a number
of other substances, viz., thymol, guaiacol, resorcin, cresorcin,
orcin, pyrogallol, pyrogallol dimethyl-ether, phloroglucin, oxy-
hydroquinone, eugenol, and safrol, but not with phenol, pyro-
catechin, hydroquinone, or pyrogallol trimethyl-ether. The re-
action cannot, therefore, be longer designated as a phloroglucin
reaction, but, in a limited sense, as a phenol reaction. The same
color reaction is produced by a number of other substances which
contain a phloroglucin molecule, e.g., phloridzin, maclurin, luteolin,
morin, catechin, filizin, gentisin, and all the phloroglycotannoides,
as in oak bark and cinchona bark.

Protective cellulose walls are composed of mixtures of lig-
nocellulose and oils and waxes, and frequently contain in addi-
tion tannin, vanillin, and other compounds. In the cuticle or epi-
dermis of leaves and green stems the cellulose is associated with
a fatty compound known as cutin (or cutose), while in the cork
of stems and roots it is combined with suberin (or suberose).
This class of celluloses is distinguished from cotton cellulose and
lignocellulose by being insoluble in sulphuric acid.

Reserve cellulose walls are those found in various seeds, as
in coffee, date, nux vomica, etc. They behave toward reagents
much like the true celluloses (Fig. 135).

Mucilage cellulose walls consist of cellulose and mucilage,
and are found in all parts of the plant, and in the case of seeds
17

'258 A TEXT-BOOK OF BOTANY.

are associated with the protective celluloses. They dissolve or
swell in water, are colored blue (as in flaxseed) or yellowish with
iodine, and are stained with alcoholic or glycerin solutions of
methylene blue.

Mineral cellulose walls are composed of cellulose and vari-
ous inorganic substances, as silica, calcium oxalate, or calcium
carbonate. These are more commonly found in the cell-wall of
the lower plants, as Algae, Fungi, and Equisetaceae. Calcium car-
bonate and silica also occur in the cystoliths of the various genera
of the Moracese and Acanthaceae (Fig. 113).

From what has just been said of the chemical composition and
structure of the cell- wall, it is seen that it consists of lamellae or

FIG. 129. i, cross-section of a bast fiber of Begonia as seen by means of the micro-
polariscope, and showing stratification of the wall. 2, polariscopic view of a sphero-crystal
of inulin in Helianthus tuberosus. — After Dippel.

layers of different substances, and in no case does it consist of
but a single substance ; but for convenience we speak of a wall as
consisting of cellulose, lignin, or suberin, meaning thereby that
the wall gives characteristic reactions for these substances.

PHYTOMELANE, an intercellular, carbon-like substance. It is
a black, structureless substance, found only in the Compositae,
being distributed around the sclerenchymatous fibers and stone
cells in a number of fruits. It has also been found in the lignified
cells of roots and stems (Fig. 131), and occasionally is found in
the parenchyma cells of Inula. In the latter it occurs more or less
crystalline, sometimes in the form of short needles or rods (Fig.
132). According to 'Hanausek (" Untersuchungen iiber die
Kohleahnliche Masse der Kompositen "), phytomelane occurs in
a large number of genera in the Compositae. It arises in the middle
lamellae and has a high content in carbon, ranging from 69.76 per

CELL-CONTENTS AND FORMS OF CELLS. 259

cent, in Helianthus annuus to 76.47 per cent, in Dahlia variabilis.
It is unaffected by most reagents except hydriodic acid. It may
readily be separated in unaltered masses upon treatment of the
tissues with Wiesner's chromic acid mixture or with Schultze's
macerating solution. Hanausek considers the phytomelane layer to
be in the nature of a mechanical protection to those fruits and seeds
in which the epidermal and hypodermal layers scale off with the
ripening of the fruit. (Consult Kraemer and Sollenberger, Amer.

I II

FIG. 130. Striation in cell-wall: I, a portion of bast fiber in Oleander, showing left
spiral bands as seen from the outer surface (a) and the same as seen from the inner surface
(b); II, portion of the bast cell of Asclepias syriaca as seen on the under surface; III, a
view of the bast fiber of Asclepias syriaca as seen when looking through the middle of the
cell; IV, portion of tracheid of Pinus sylvestris, showing two views of the striations of the
wall. — After Dippel in "Das Mikroskop."

Jour. Pharm., 1911, p. 315; Senft, Pharm. Post, 1914, No. 30;
Hanausek, Ber. d. d. bot. Ges., 1911, p. 558.)

LAMELLA. — In some cells, as in lignified cells, the lamellae
are quite apparent. In other cases the use of reagents, as chromic
acid or chlor-zinc iodide, is necessary to bring out this structure.
The layering which is observed in transverse sections of the cell-
wall is spoken of as stratification of the wall (Fig. 129), whereas
the layering observed in longitudinal or tangential sections is
referred to as striation of the wall (Fig. 130).

2(5o

A TEXT-BOOK OF BOTANY.

Thickening or Marking of Walls. — In the formation of
the wall each cell appears to work in unison with its neighbors
for the building up of the plant. The thickening of the walls
of the cell is primarily for the purpose of strengthening the walls,
but if the walls were uniformly thickened, osmosis, or the trans-
ferral of cell-sap from one cell to another, would be hindered.

FIG. 131 . Phytomelane, an intercellular carbon-like substance occurring on the outer layers
of the stone cells in Brauneria pallida (Echinacea angustifolia) .

Thus we find that the contiguous walls of the cells are thickened
at definite places opposite each other, leaving pores or canals
which permit rapid osmosis. The pores thus formed are known
as simple pores, and when seen in surface view are somewhat
elliptical or circular in outline, and may be mistaken for some of

CELL-CONTENTS AND FORMS OF CELLS. 261

the cell-contents. These thickenings assume a number of forms,
which are quite characteristic for the plants in which they are
found. They may have the form of transverse or oblique rings,

FIG. 132. Phytomelane in root of Inula Helenium. 1-3 showing intercellular spaces
with carbon-like substance; 4-8, striated structure of intercellular phytomelane in sections
which have been allowed to remain in solutions of hydrated chloral or potassium hydrate
for some days; 9, a large crystal-like aggregate in a schizogenous-like reservoir formed in
contiguous intercellular spaces of 5 parenchyma cells; 10, separated crystal-aggregates
and rod-shaped masses of Phytomelane. — After Senft.

longitudinal spirals, or may be ladder-like or reticulate in appear-
ance (Figs. 141-144). In other instances the thickening of the
wall is quite complex, as in the wood of the pines and other Conif-
erse (Fig. 68). The thickening, or sculpturing, as it is sometimes

262 A TEXT-BOOK OF BOTANY.

called, may not only occur on the inner surface of the wall, when
it is spoken of as CENTRIPETAL, but may also take place on the
outer surface, when it is known as CENTRIFUGAL, as in the spores
of lycopodium and the pollen grains of the Compositse.

FORMS OF CELLS.

Upon examining sections of various portions of the plant, it
is observed that not only do the cell-contents and cell-wall vary
in composition, but that the cells are of different forms, depend-
ing more or less upon their functions. Groups of cells which
are similar in form and function constitute the various tissues of
the plant; and include: (i) parenchyma cells, (2) mechanical
cells, (3) conducting cells, and (4) protective cells.

Parenchyma. — Under the head of parenchyma are included
those cells which are nearly isodiametric and thin-walled, the walls
consisting of cellulose lamellae (Fig. 134). They may contain
both protoplasmic and non-protoplasmic cell-contents. Accord-
ing to the function and nature of contents, five kinds of paren-
chyma cells are recognized: (a) CHLOROPHYLL-PARENCHYMA or
assimilation parenchyma contains numerous chloroplastids and
occurs in leaves and all green parts of the plant, (b) RESERVE
PARENCHYMA occurs in seeds, roots, rhizomes, leaves, and contains
starch, aleurone grains, fixed oils, and other reserve materials. In
some instances the parenchyma, as in the endosperm of date,
ivory nut, etc., may be very thick-walled (Fig. 135). The paren-
chyma in stems and leaves of various of the orchids, as well as
that of plants of arid regions, which store water, may be included
in this group, (c) CONDUCTING PARENCHYMA is found either
associated with the sieve or with the tracheae, the cells of the
phloem conveying the plastic substances, while those of the xylem
convey water and salts. The cells of the pith and cortex are,
as a rule, not utilized for the rapid translocation of food materials
to far distant parts, although every living cell and every tissue
has a certain power of translocation, and no doubt different
parenchymatous tissues exhibit varying degrees of functional
activity and differentiation. Thus large quantities of reserve
materials are rapidly transferred to the developing embryo through
the cells of the endosperm, and in young seedlings further trans-

CELL-CONTENTS AND FORMS OF CELLS. 263

ference probably takes place mainly through the cortical and
medullary parenchyma, (d) SPONGY PARENCHYMA, or loose,
spongy tissue with large intercellular spaces. The cells of this

FIG. 133. A cell from sassafras pith showing intercellular space (i); middle lamella
(m); layer of lignin (1); and layer of cellulose (c), which is subsequently modified to muci-
lage; simple pores (p) which are seen in the lower wall, the section being slightly oblique.
B, portion of wall showing the appearance of the pores when the view is transverse to the
wall and the focus is at the upper part of the pore (a) or at the lower part (b).

type vary from slightly branched cells, as in the mesophyll of
leaves, to those which are strongly branched and stellate, as in
Juncus, Pondederia, and the stems of various marsh plants. In

264

A TEXT-BOOK OF BOTANY.

Calamus the cells are so arranged that very large intercellular
spaces are formed (Fig. 134). (e) A number of modifications
of typical parenchyma also occur, some of the cells being either
quite thick-walled or considerably elongated. The walls of pith-

C

FIG. 134. Forms of cells. A. — Transverse section of the pith of Tradescantia vir-
ginica: I, intercellular space; W, cell wall. B. — Transverse section of calamus rhizome
showing a large oil-secretion cell, smaller cells containing starch, and large intercellular
spaces (I). C. — Transverse section of the stem of Phytolacca decandra showing collenchy-
matous cells beneath the epidermis. D. — Longitudinal section of taraxacum root showing
branched laticiferous tissue (L). E. — Transverse section of pyrethrum root: R, oil-secre-
tion reservoir with oil globules; I, cells with sphere-crystals of inulin, such as separate in
alcoholic material; L, cells containing irregular masses of inulin, as found in dried material.
F. — Longitudinal section of stem of Cucurbita Pepo: S, sieve-cell with protoplasm-like
contents, and transverse walls (sieve plates) showing simple pores.

parenchyma may consist of lamellae of lignocellulose and mucilage,
as in Sassafras pith (Fig. 133).

MECHANICAL TISSUE includes all those cells which serve to
keep the various parts of the plant in their proper positions, one

CELL-CONTENTS AND FORMS OF CELLS. 265

with reference to the other, and which enable it to withstand
undue strain and pressure. There are two principal forms, namely,
(a) collenchyma and (b) sclerenchyma.

THE COLLENCHYMA CELL is elongated, prismatic, with soft

FIG. I3S. A, cells of endosperm of the seed of the date palm (Phoenix dactylifera) , the
one normal and the other showing the stratification of the wall after treatment with
chlor-zinc-iodide.

B, cell of endosperm of Phytelephas macrocarpa (vegetable ivory) showing lamellation
and spherite structure in the wall after treatment with chlor-zinc-iodide, clove oil, chromic
acid or certain other reagents.

C, cell of endosperm of Strychnos Nux-vomica after treatment with iodine and potas-
sium iodide solution.

D, opposite pores in the walls in contiguous cells of vegetable ivory showing striae
between them after treatment with iodine solution.

Walls consisting mainly of cellulose and never lignified ; the contents
being rich in water. In transverse section it is readily distin-
guished by the local thickening of the walls, i.e., at the angles of

266

A TEXT-BOOK OF BOTANY.

the cells (Fig. 134, c). Pores are rare, but when present they
are annular or slit-like. Collenchyma occurs near the surface
of plant organs, as herbaceous stems, when they form ribs, as

FIG. 136. Various forms of stone cells: A, epidermis of hyoscyamus seeds; B,
pericarp of pimenta, containing brownish tannin masses; C, seed-coat of coffee; D, seed-coat
of almond; E, transverse section of seed-coat of white mustard showing beaker cells; F,
surface view of beaker cells of seed-coat of white mustard; G, transverse section through
stone cells of endocarp of olive, the lumen containing air; H, a stone cell from the periderm
of calumba, containing numerous monoclinic prisms of calcium oxalate; I, various forms
of stone cells isolated from pericarp of star anise.

in the Umbelliferse. It is also found in leaves and in fruits, as in
the Umbelli ferae.

SCLERENCHYMA CELLS include all of those cells which have
more or less uniformly thickened walls composed of lignocellulose,

CELL-CONTENTS AND FORMS OF CELLS. 267

permeated by simple or branching pores. They have a thin layer
of protoplasm enclosing large vacuoles, and may contain tannin
or tannin-like masses, and occasionally calcium oxalate crystals
or starch, and in dead cells the lumen or cell cavity contains
air. Two kinds of sclerenchyma are recognized: i, in which the
cells are more or less isodiametric (Figs. 136-138), known as
stone cells (short sclerenchyma) ; and 2, in which the cells
are elongated (Figs. 139-141), being from 0.5 to 2 mm. in
length and known as sclerenchymatous fibers (or long scleren-
chyma). Of these latter, two kinds are distinguished, chiefly
according to their position in the plant, namely, bast fibers, or
stereome, and wood fibers, or libriform. Seldom are the wood and

FIG. 137. Several forms of stone cells: A, white oak bark; B, white cinnamon or
canella bark (Canella alba); C, seed-coat of capsicum.

bast fibers in the same plant uniform in structure and composition,
as in glycyrrhiza and althaea. On the other hand, they are with
difficulty distinguished in monocotyledonous roots, and the term
sclerenchymatous fiber is here best employed to include both kinds
of cells. In the study of powdered drugs the term sclerenchyma-
tous fiber may be employed with advantage when speaking O'f wood
and bast fibers, as in this condition they are not readily distinguish-
able. It is usual in plant anatomy to include as stereome all ligni-
fied fibers not directly associated with the vessels of the mestome
strands (or vascular bundles).

STONE CELLS or SCLEROTIC CELLS are parenchymatous cells
with very thick, lignified walls, composed of numerous lamellae,

268

A TEXT-BOOK OF BOTANY.

which are permeated with simple and not infrequently branching
pores. They vary in form, being usually polygonal, or more or
less irregular in outline, sometimes branching. The lamellation of
the walls is brought out by the use of swelling reagents, as solu-
tions of the alkalies, hydrated chloral, chromic acid, etc. In
typical stone cells the walls always give the characteristic re-
action for lignocellulose with acid solutions of either phloro-
glucin or aniline sulphate. The lumina of the cells frequently
contains a reddish, amorphous substance, seldom are crystals of
calcium oxalate present (Fig. 136, //), and not infrequently they
are filled with air (Fig. 136, G). In the identification of com-

FIG. 138. Various forms of stone cells in star anise, the fruit of Ilhciunt anisatum.

mercial products the study of the contents of the stone cells is
frequently as important as that of the forms of cells.

BAST FIBERS or STEREOMATIC CELLS are sclerenchymatous
fibers, occurring in the bark and usually associated with sieve cells.
They represent the skeleton of plants and are the most important
mechanical tissues of the bark, being much firmer than the collen-
chyma. They are very long, spindle-shaped, with more or less
thick walls, and provided with slit-like, oblique pores. The walls
may consist of cellulose, as in the fibers of flax, but they are
usually more or less lignified; the lumina is narrow and usually
contains air. In transverse sections the fibers are more or less

CELL-CONTENTS AND FORMS OF CELLS. 269

circular, ellipsoidal or polygonal, depending upon the pressure
upon the walls and whether they are isolated or in groups. They
vary in diameter and length, and also in the thickness of the walls ;
while most bast fibers are between I and 2 mm. in length, they
may be more than 200 mm. in length, as in Boehmeria nivea.
The ends may be more or less obtuse or drawn out to a fine point ;

FIG. 139. Transverse (t) and longitudinal (1) sections of commercial fibers: A, long
staple cotton from the seeds of Gossypium; B, Kentucky hemp, the bast of Cannabis
sativa; C, jute, the bast of Corchorus; D, sisal, the fibers from the leaves of the Century
plant (Agave rigida Sisalana) ; E, raphia, the outer layers of leaflets of Raphia. pedunculata;
F, ramie, the fibers from a Formosa nettle; G, Merino wool; H, silk; I, artificial silk, the
figure on the left showing a false lumen due to the infolding of the edges, f, fungal hyphae;
c, rosette aggregates of calcium oxalate; p, parenchyma cells.

occasionally they are somewhat branched (Fig. 140). The pores
in surface view are narrow elliptical and arranged according to a
left-handed spiral. The spiral arrangement of the component
elements of the wall is supposed to give strength to the fibers,
and, according to Schwendener, they will sustain a weight nearly
equivalent to that of wrought-iron and steel.

270

A TEXT-BOOK OF BOTANY.

Bast fibers may be isolated by the use of Schulze's macerating
fluid (which is prepared by dissolving a few crystals of potassium
chlorate in nitric acid) and moderately heating the solution con-
taining the material either on a slide or in a test-tube.

The mechanical tissue consisting of cells resembling bast fibers
and occurring in leaves and fruits is usually referred to as
stereome.

WOOD FIBERS or LIBRIFORM CELLS are sclerenchymatous fibers

1

( /

1 • r ' i ? *! 1 1 f .

i

FIG. 140. A, C, bast fibers of the bark of Cinchona succirubra; B, bast fibers of the
bark of Cinchona Ledgeriana; D, stone cells of Cuprea bark (Remijia peduncuiata) . — After
Oesterle and Tschirch.

occurring in the wood and are usually associated with the tracheae.
They are scarcely to be distinguished from the bast fibers except
by their position, and are the strengthening cells of the xylem.
While the bast fiber is frequently not lignified, the walls of the
wood fibers usually consist of lignocellulose, and usually give
quite pronounced color reactions with acid solutions of either
phloroglucin or aniline sulphate. Wood fibers are usually more

CELL-CONTENTS AND FORMS OF CELLS. 271

abundant than bast fibers in the same plant, and, while the bast
fibers may be wanting, the wood fibers, with few exceptions, are
always present. Wood fibers seldom attain the length of bast

BF

FIG. 141. Longitudinal-transverse section of licorice rhizome including the cambium:
P, parenchyma; T, tracheae or ducts; WF, wood fibers; C, cambium; S, sieve; CF, crystal
fibers; BF, bast fibers; MR, medullary ray.

fibers. They are not infrequently branched at the ends, and,
besides a thin protoplasmic layer, they usually have no other
contents than water or air. They frequently have yellowish
walls, characteristic of stone cells, and also exhibit a similar
lamellation and refraction of the wall.

272

A TEXT-BOOK OF BOTANY.

Conducting cells or mestome include those cells which are
chiefly concerned in the transferral of either crude or assimilable

FIG. 142. Development of spiral bands in the mechanical cells of young fruits of Fegatella
conica (Hepaticse): I, young cell with vacuoles and small starch grains; II, portion of an older
cell showing formation of large vacuoles in the protoplasm, the strands of which are arranged
in a left-hand spiral; III, showing spiral arrangement of protoplasm; IV, portion of cell
as in III treated with a sugar solution and showing plasmolysis of protoplast; V, showing
formation of band; VI, a cell as in V treated with sugar solution, showing the protoplasm
arranged along the thickened portions of the wall where the bands are forming; VII, the
mature cell showing lignified spiral bands. — After Dippel in "Das Mikroskop."

food materials. The more or less crude inorganic materials are
carried from the root through the woody portion of the stem to

CELL-CONTENTS AND FORMS OF CELLS. 273

the leaves, and from the leaves the products of photosynthesis,
as well as other plastic substances, are distributed through some
of the tissues of the bark to other parts of the plant. The tissues
or elements of the wood which conduct food materials are of sev-
eral forms and include tracheae or vessels (also called " ducts "),
tracheids, and conducting parenchyma ; and the elements of the
bark which transport the assimilable materials comprise the lep-
tome and conducting parenchyma (Fig. 141). Water-conducting
elements (TRACHEAL ELEMENTS) comprise the vessels (tracheae)
and the tracheids, which resemble each other, except that the latter
are single cells of prosenchymatic shape, while the former are
very long tubes, varying from cylindrical to prismatic in shape, and
consist of long rows of cells which are superimposed length-
wise, the transverse walls being usually obliterated.

S D C_ _R

FIG. 143. Forms of tracheae or vessels. A. — Longitudinal section of stem of Cucurbita
Pepo showing various forms of tracheae: A, annular; S, spiral; D, double spiral; C, close
annular; R, reticulate. B. — Tracheae in glycyrrhiza rhizome : W, wall; B, bordered pores;
P, oblique simple pores.

The tracheae or vessels are formed by the disintegration and
removal of the transverse walls between certain superimposed
cells, forming an elongated cell or tube, which occasionally retains
some of the transverse walls (Figs. 142-144). The longitudinal
walls are relatively thin and consist of lignocellulose, giving pro-
nounced reactions with phloroglucin or aniline sulphate.

Four types of vessels or tracheae are known : annular, spiral,
reticulate, and porous. Those having the thickenings in the form
of horizontal or oblique rings are known as ANNULAR TRACHEAE;
those having the thickenings in the form of spirals, which usually
run from right to left, are known as SPIRAL TRACHEA; those
having the thickenings in the form of a reticulation are known as

18

274

A TEXT-BOOK OF BOTANY.

RETICULATED TRACHEAE, and those with spherical or oblique slit

pores are known as POROUS TRACHEAE or vessels (Figs. 142-144).

In those vessels in which but few of the transverse walls are

obliterated, the walls are marked by both simple and bordered

FIG. 144. Types of tracheae or vessels. A, vessels with annular and spiral thickenings
in Phlox Carolina; B, longitudinal section through fibrovascular bundle in aconite, showing
porous (p) and spiral tracheae (t), bast fibers (b), and some of the collenchyma cells (c);
C, longitudinal section showing reticulate tracheae in scopolia; D, longitudinal section of
the woody part of the rhizome of Spigelia, showing tracheae (t) , tracheids (h) , tracheae (r)
with yellowish-brown, gum-like masses; E, portion of xylem of stem showing in Hyos-
cyamus tracheae (t) with bordered pores and wood fibers (w), with simple oblique pores.

,pores, which latter are described under tracheids. Vessels contain
water, water- vapor, and air; in some cases they contain sugar,
tannin, mucilage, or resin.

CELL-CONTENTS AND FORMS OF CELLS. 275

The tracheids are intermediate in character between tracheae
and libriform, resembling the former in possessing bordered pores
(Fig. 145) and scalariform thickenings; and the latter in being
true cells, which are usually elongated and quite thick-walled,
the walls giving distinct reactions for lignocellulose with phloro-
glucin or aniline sulphate.

One of the chief characteristics of tracheids is the BORDERED
PORES (Fig. 145). These differ from simple pores in that the
wall surrounding the pore forms a dome-shaped or blister-like

FIG. 145. Bordered pores of the tracheids of the wood of Abies alba as viewed in
longitudinal section: m, middle lamella; v, i, middle and inner layers of walls of contigu-
ous cells ; C, pore-canal through which sap passes from one cell to another ; L, dome-
shaped cavity of pore; S, separating wall or closing membrane which is usually thickened
in the middle as shown at t. In older cells the separating membrane is broken as shown
in the lower pore in figure 2. At the right in figure 4 is shown a surf ace view of a bordered
pore, the dotted lines indicating the relation of the circles to the structure of the pore. —
After Vogl.

protrusion into the cell. On surface view the pores are either
circular or elliptical in outline, the dome being circular or, if the
pores are numerous and arranged close together, more or less
polygonal (Figs. 143, 144).

The number and distribution of bordered pores in the Coni-
ferae are quite characteristic for some of the genera, and may be
studied in any of the pines, the pores being most numerous in
the radial walls (Fig. 69).

276

A TEXT-BOOK OF BOTANY.

The leptome or sieve is distinguished from the other con-
ducting elements in that the walls are thin and are composed of
cellulose (Fig. 146). It consists of superimposed elongated cells,
the transverse walls of which possess numerous pores which are
supposed to be in the nature of openings, permitting of the

in

FIG. 146. Different forms of sieve pores: I, portion of sieve tube of Bryonia alba,
II of Cucurbita Pepo, A longitudinal section and B in transverse section; III, portion of a
sieve cell of Larix europcea showing round sieve pores; IV, an old sieve plate in Bryonia
alba treated with chlor-zinc-iodide, showing the striated callous plates (c), (z) cell-wall,
(s) sieve plate, (i) contents of sieve tube, (h) cell membrane, (c) callous plates. — After Dippel
in "Das Mikroskop."

direct passage of the contents from one cell to the other. This
transverse wall, which may be either horizontal or oblique, is
known as the SIEVE PLATE, and the thin places as pores of the
sieve. The sieve plates are sometimes also formed on the longi-

CELL-CONTENTS AND FORMS OF CELLS. 277

tudinal walls. When the activities of plants are suspended during
the winter, there is formed on either side of the sieve plates a layer
of a colorless, mucilaginous substance, known as callus, which has
somewhat the appearance of collenchyma, but is colored brownish
by chlor-zinc iodide.

The sieve cells contain an albuminous substance somewhat
resembling protoplasm ; in some instances starch grains have also
been found.

When the activities of the sieve tubes have ceased, they be-
come altered in shape, and are then known as altered sieve. In
the drying of plants a similar alteration is produced, and the
sieve of vegetable drugs is referred to as " obliterated " sieve.

Protecting cells include those cells which are located on the
outer parts of the plant. The function of these cells is to lessen
the rate of transpiration, or the giving off of water ; to furnish
protection against changes of temperature, and to protect the
inner tissues against the attack of fungi and insects ; they also have
a mechanical function (Figs. 147, 157).

Depending principally upon their composition, these cells may
be divided into two classes, namely, epidermal cells and cork cells.

The epidermal cells constitute the outermost layer of the
plant. They contain cytoplasm, but the plastids in some instances
are wanting; in petals, etc., they also contain dissolved color-
ing principles ; and on account of the relatively large amount of
water which they contain they are classed among the important
water-reservoirs of the plant.

The outer walls are principally characterized by one or more
lamellae of cutin, these uniting to form a continuous wall. The
cutin is often associated with wax, this constituting the bloom of
fruits ; less frequently such inorganic substances as calcium car-
bonate, calcium oxalate, and silica are present, and not infre-
quently mucilage is present, as in the walls of certain seeds (Fig.

119, ^)-

On surface view the form of these cells varies from nearly
isodiametric to oblong; they may also be polygonal or branched.
In transverse section their radial diameter is much the shorter.
In some instances the inner and side walls are considerably thick-
ened, as in the seeds of a number of the Solanaceae (Fig. 136, A).

278

A TEXT-BOOK OF BOTANY.

The epidermis usually consists of a single layer of cells, but
may have additional layers underneath forming the HYPODERMIS,
as in the upper surface of the leaves of species of Ficus (Fig. 113) ;

PIG. 147. Stomata and water-pores. A. — Transverse section through lower surface
of leaf of stramonium: stoma, with guard cells (G), containing cytoplasm, nucleus and
chloroplastids; N, surrounding cells; A, intercellular cavity usually filled with cell-sap or
watery vapor; E, epidermal cells; M, mesophyll. B. — Surface section of upper surface of
leaf of Viola tricolor showing four stomata. C. — Surface section of under surface of leaf of
Viola tricolor showing five stomata. D. — A section through the margin of the leaf of Viola
tricolor showing a tooth with three water-pores. E. — A water-pore of Viola tricolor in
surface section.

in some instances the hypodermis undergoes a mucilage modifica-
tion, as in the leaves of buchu.

Stomata. — Distributed among the epidermal cells are pairs
of crescent-shaped cells known as a STOMA, and having an open-

CELL-CONTENTS AND FORMS OF CELLS. 279

ing or pore between them, which leads to a cavity beneath it. The
two cells of the stoma are known as GUARD CELLS (Fig. 147, G).
The adjoining walls of the guard cells are alike in transverse sec-
tion, but the cells vary in shape in different plants. The guard
cells are more or less elastic, and when the cells are turgescent, as
when there is an abundance of water and root pressure is strongest,
the contiguous walls of the cells recede from each other, forming
an opening between them, thus permitting the exit of the excess of
water taken up by the plant and the exhalation of the oxygen
given off during assimilation, as well as the intake of the carbon
dioxide used in photosynthesis. On the other hand, when the
amount of water in the plant is reduced below the normal and the
plant shows signs of wilting the guard cells flatten and the open-
ing or pore is closed (Fig. 214). The cells beneath the stoma are
loosely arranged, so that the air containing carbon dioxide may
be readily diffused to the cells containing the chloroplastids.

The guard cells may be slightly raised above or sunk below
the surrounding epidermal cells, the number of the latter being
characteristic for certain plants. (Compare Figs. 147, 211-218.)

Stomata occur in the largest numbers on the blades of foliage
leaves, being more numerous on the under surface, except in
aquatic plants, where they occur only upon the upper surface.

Water Pores. — Near the margin of the leaf and directly over
the ends of conducting cells, not infrequently occur stomata, in
which the function of opening and closing is wanting, and which
contain in the cavity below the opening water and not air, thus
differing from true stomata (Fig. 147, D, E). These are known
as WATER PORES, and they give off water in the liquid form, the
drops being visible on the edges of the leaves of nasturtiums,
fuchsias, roses, etc., at certain times.

Plant Hairs. — The epidermal cells are sometimes specially
modified centrifugally, giving rise to papillae, to which the velvety
appearance of the petals of flowers is due; in other cases this
modification is in the form of hairs or trichomes (Figs. 148-155).
These may be unicellular or multicellular, and in addition the
latter may be glandular or non-glandular. Glandular hairs possess
a head-like apex, consisting of one or more cells, and they secrete
oil, mucilage, and other substances (Figs. 124, 125, 149, 150).

A TEXT-BOOK OF BOTANY.

In the examination of technical products, as also in taxonomic
work, the study of plant hairs is very important. They show a
great diversity in form in not only genera and families but even
in related species. They vary considerably in their distribution

FIG. 148. Mostly non-glandular hairs and a few of the small glandular hairs covering
the surface of the fruits of several species of Rhus: g, hairs on Rhus glabra, being more or
less broadly top-shaped or carrot-shape to spatulate and occasionally narrow elliptical and
from o.ioo to 0.400 mm. in length; b, hairs on Rhus typhina, being long and needle-like,
varying from 0.750 to 1.500 mm. in length; c, hairs of Rhus glabra borealis, being intermedi-
ate between those of Rhus glabra and Rhus typhina, varying from elongate spatulate and
narrow cylindrical to needle-shaped, and from o.ioo to i.ooo mm. in length.

not only in related species, but sometimes in varieties of the same
species they show marked variation in size and form. In some
natural hybrids intermediate forms of hairs of the parent species

CELL-CONTENTS AND FORMS OF CELLS. 281

are found. This was pointed out by Kraemer in some studies
on Rhus glabra and Rhus typhina (Amer. Jour. Pharm., 1913,
p. 404), in which a herbarium specimen in the New York Botanical
Garden and labelled by Britton as Rims glabra borealis shows
hairs which in form and size are intermediate between those of
R. glabra and R. typhina (Fig. 148).

Plant hairs may be divided into two principal groups: I.
GLANDULAR HAIRS, or those in which the summit consists of one
or more cells which secrete beneath the cuticle either mucilage,
oils, or oleo-resins, and the summit of the hair possesses a more
or less globular form. II. NON-GLANDULAR HAIRS, or those in
which the summit of the hair consists of one or more rounded or
pointed cells in which no secretion is formed beneath the cuticle.

GLANDULAR HAIRS may be divided into five different groups :

1. Unicellular glandular hairs consist of a single tubular
cell, the upper portion being more or less swollen and rounded
(Fig. 149, A, B). Hairs of this type occur in the Euphorbiaceae,
in which they more or less resemble Papillae. In the Compositae
they contain a latex and appear to be connected with the laticif er-
ous vessels. They also occur in the Anacardiaceae, Cornaceae,
Geraniaceae, Leguminosae, Malvaceae, Menispermaceae, Onagraceae,
Piperaceae, Ranunculaceae, Tiliaceae and Zygophyllaceae.

2. Multicellular glandular hairs consist of a number of forms ;
either they are differentiated into a stalk and a head, or the stalk
may be wanting when the hair has a spatulate or clavate form.
These are often very characteristic for certain families, as the
glandular hairs in the Labiatae (Fig. 124), which possess a short
stalk, and a head portion with eight cells, the cuticle being raised
like a bladder owing to the great accumulation of secretion. There
are a great many types of multicellular glandular hairs (Fig. 149).
They may be uniseriate, i.e., consisting of a series of cells with
either a unicellular head (Fig. 149, C, E, K, M), as in the Meni-
spermaceae, Araliaceae, Malvaceae, Caryophyllaceae, Geraniaceae,
etc., or they may be bicellular (Fig. 149, D, F, H, J, L, 0), as in
the Cruciferae. The heads may consist of two to four cells (Fig.
149, G, V , Y), as in the Burseraceae, or eight cells, as in the Labiatae
(Fig. 149, W). Multicellular glandular hairs have been found in
the following families: Aceraceae, Anacardiaceae, Araliaceae, Be-

282

A TEXT-BOOK OF BOTANY.

FIG. 149. Various types of glandular hairs. Unicellular hairs on Julocroton fus-
cescens (A), Croton monanthogynus (B). Uniseriate uni-glandular hairs on Zollikoferia
nudicaulis (C), Silene villosa (E), Geranium favosum (K), Boerhaavia repens (M). Glandular
hairs with two-celled heads on Hesperis glutinosa (D), Pityrodia salvifolia (F), Cyclamen
persicum (H), Lysimachia Nummularia (]), Chenopodium Botrys (L), Diospyros Kaki (O).
Glandular hairs with four-celled heads on Humulus Lupulus (G), Boswellia papyrifera (V),
Humulus Lupulus (Y). Glandular hairs with five-celled heads on Combretum aculeatum (Z),
Humulus Lupulus (Y). Glandular hairs with six-celled heads on Rhododendron Dalhousia
(X), hair characteristic on the Phaseolece (U). Glandular hairs with eight-celled heads on
•Lavandula vera (W). Glandular hairs with multicellular heads on Pieris floribunda (N),
Begonia carolinicefolia (S), Begonia pretoniensis (s). Glandular hairs with four and eight
cells respectively on Picramnia coccinea (P). Glandular hairs with two and four cells re-
spectively on Cistus ladaniferus (R). Double glandular hair on Rhododendron lanatum (T)
— Adapted from Solereder and redrawn by Hogstad.

CELL-CONTENTS AND FORMS OF CELLS. 283

goniaceae, Berberidacese, Bixaceae, Borraginaceae, Burseraceae.
Capparidaceae, Caprifoliaceae, Caryopyhllaceae, Chenopodiaceae,
Combretaceae, Compositae, Convolvulaceae, Cornaceae, Crassulaceae,
Cruciferae, Cucurbitaceae, Dipsaceae, Ericaceae, Euphorbiaceae,
Fagaceae, Geraniaceae, Hippocastanaceae, Hydrophyllaceae, Labi-
atae, Leguminosae, Malvaceae, Melastomataceae, Meliaceae, Meni-
spermaceae, Moraceae, Myrsinaceae, Nolanaceae, Nyctaginaceae,
Nymphaeaceae, Piperaceae, Platanaceae. Plantaginaceae, Polemoni-
aceae, Polygonaceae, Portulacaceae, Primulaceae, Rosaceae, Ru-
taceae, Sapindaceae, Saxifragaceae, Scrophulariaceae, Simarubaceae,
Solanaceae, Sterculiaceae, Theaceae, Tiliaceae, Umbelli ferae, Ul-
maceae, and Valerianaceae.

3. Glandular leaf-teeth, as the name would signify, include
the glandular hairs formed on the lobes of leaves. They vary
in structure and may secrete mucilage, as in the Violaceae (Fig.
120) and in some of the Compositae, or they may secrete, in addi-
tion, resin, as in the Rosaceae, or calcium oxalate, as in the
Saxifragaceae.

4. Special forms of multicellular glands are found in the
Aceraceae, in which a pair of glands are fused together. In some
of the Compositae and Moraceae a group of glandular hairs are
united. Other special types also occur in the Droseraceae, Ana-
cardiaceae, Leguminosae, etc.

5. Hair-like external glands having a complicated structure
have been observed in a number of families. They are limited
to certain portions of the plant, being found in the Apocynaceae
at the base of the leaves and in the Rubiaceae only on the stipules.
They are usually very large, secreting considerable mucilage and
resin. The glandular, shaggy hairs occurring on the stipules in
the Rubiaceae are of this type, the secretion being often so abundant
that the young leaves emerging from the stipular sheath are
coated with this resin, which is even retained by the mature
leaves.

II. NON-GLANDULAR HAIRS are of three general types: I.
Simple hairs (Figs. 148, 151), which may be unicellular or uni-
seriate, — i.e., consisting of a series of superimposed cells. 2.
Peltate or stellate groups (Fig. 153, D, E, H, K}, consisting of
two or more hairs united at the base and spreading like a star.

A TEXT-BOOK OF BOTANY.

FIG. 150. Forms of glandular hairs: A, corkscrew-like hairs from the inner surface
of the spurred corolla of lavender; B, longitudinal section of rhizome of Dryopteris mar-
ginalis showing large intercellular space and an internal oil-secretion hair; C, hairs from
stramonium leaf; D, hairs from Digitalis; E, hair from sage; F, hair from eriodictyon; G.
hairs from inner walls of pericarp of vanilla; H, hair from cannabis indica; I, hairs from
surface of fruit of Rhus glabra; K, hairs from belladonna leaf.

CELL-CONTENTS AND FORMS OF CELLS. 285

These may consist of one or more series of cells, separated by a
columnar cell. 3. Shaggy hairs (Fig. 153, G), in which the
epidermal layer of the column of cells is modified to papillae

PIG. 151. Forms of non-glandular hairs: A, hair from the epidermis of strophanthus;

B, a hair from the capsule of Mallotus philippinensis (found in the drug known as kamala) ;

C, hairs from the leaves and bracts of cannabis indica, two of them containing cystoliths
of calcium carbonate; D, a hair from the under surface of the leaf of senna; E, hairs from
leaf of digitalis; F, two forms of hairs from sage leaf; G, two forms of hairs from the leaves
of wormwood (Artemisia Absinthium): a T-shaped non-glandular hair and a short glandular
hair.

which are directed upwards, giving the surface of the plant the
appearance of being covered with rough hairs or wool.

Non-glandular hairs occur on a large number of plants. They

286

A TEXT-BOOK OF BOTANY.

vary in form and are very characteristic in a great many plants.
The terms used to describe the various types of hairs are in a
few instances rather simple, but there are so many modifications
that nothing short of an illustration will suffice to define them.
The simple hairs may be divided into a number of sub-divisions :
(a) Papillose hairs, being short outgrowths of the epidermal cells,
somewhat resembling the papillae found on the ventral surfaces of
petals. This form is found in a relatively few families, (b)
Unicellular hairs, being outgrowths considerably longer than
papillae and occur in a large number of plants. This is also true
of a third type (c), known as uniseriate hairs and in which there

B

G

FIG. 152. Forms of non-glandular hairs: A, twisted hairs from under surface of
leaf of eriodictyon; B, lignified hairs from the epidermis of nux vomica; C, branching
hairs from the leaf of mullein (Verbascum thapsus).

are two or more cells connected as in a chain. Among special
terms frequently used the following may be mentioned: (d)
Hooked hairs (Fig. i$^,A,B), in which the summit is bent in the
form of a hook, (e) Two-armed hairs (Fig. 153, D), in which
the summit consists of two cells which diverge from each other
and spread out horizontally or parallel to the surface of the leaf.
(/) Stellate hairs (Fig. 151, B) consist of a group of cells ar-
ranged around a simple point, as in the Cruciferae and Saxifra-
gacese. (g) Peltate hairs (Fig. 153, E) consist of a group of
radially arranged cells, of which all or only some reach the centre
of the shield, as in the Solanaceae, Malvaceae, Loganiacese, and

CELL-CONTENTS AND FORMS OF CELLS. 287

Rosaceae. (h) Candelabra or abietiform hairs (Fig. 153, L) are
those which have a uniseriate main axis, interrupted at intervals
by whorls of ray cells. These show considerable variation and are
very characteristic in the Solanacese, Acanthaceae, Leguminosae,
Labiatae, and Euphorbiaceae. (i) Stinging hairs (Fig. 153, /),
or those containing an irritating substance, as in the stinging nettle
and other plants of the Urticaceae. The hairs are rather long, the

-TIL

FIG. 153. Several types of non-glandular hairs. Crystal hairs on Malanea macro-
Phylla: A, showing hair with a single row of crystals; B, cell with 2 rows of crystals; C,
transverse section of B, showing crystals. Two-armed hairs on Artemisia Absinthium (D)
and Dichondra repens (II) ; F, uniseriate non-glandular hair on Pongamia glabra; E, longi-
tudinal view showing two of the cells of a peltate hair on 'Solatium argenteum; G, shaggy
hair on Calandrinia umbellata; J, upper portion of stinging hairs of Urtica dioica; K, cup-
shaped peltate hair on Rhododendron A nthopogon; L, candelabra hair on Verbascum Thap-
sus. — Adapted from Solereder and redrawn by Hogstad.

summit bearing a spherical or ovoid head, which is obliquely in-
serted and rather easily detached, thus leading to the emission of
the contents. The stinging sensation was formerly stated to be
due to formic acid, but it is now supposed to be in the nature of a
substance related to the ferments. (/) Crystal-containing hairs.
Calcium oxalate (Fig. 153, A, B, C), either in the form of rosette
aggregates or prisms or needles, is sometimes present in the

288

A TEXT-BOOK OF BOTANY.

FIG. 154. Hairs in the Compositae: A, slightly curved or hooked hairs on the corolla
of Dandelion; B, hooked hairs on the filaments of Inula; C, hairs on pappus of Tragopogon
pratensis; D, hair from akene of Tragopogon pratensis; E, portion of barbed hair upon
pappus of Inula; F and G, double hairs fromacheneof Tagetes tenuifolia; H, double hairs
from achene of Inula; J, double hair from corolla of Calendula.

CELL-CONTENTS AND FORMS OF CELLS. 289

FlG. 155. Characteristic branching hairs found on the stem, leaves, and calyx of

Hyoscyamus muticus.

stinging hairs of some of the Euphorbiaceae, as well as in some of
the genera of the Cornaceae, Geraniaceae, Rosacese, and Saxi-
fragaceae.
19

290 A TEXT-BOOK OF BOTANY.

LIGNIFIED HAIRS. — In some seeds, as in nux vomica, the hairs
are strongly lignified, as are also the bases of the hairs of Stro-
phantus hispidus. This is due to a lignocellulose modification of
the wall, and, since broken hairs look more or less like fibers, one
might easily be led astray in the study of powdered drugs. It is
not usual to make a microchemical study of the walls of non-
glandular hairs, but this subject is well worthy the attention of
investigators.

FALSE PLANT HAIRS. — While it is impossible for the careful
student of plant morphology to mistake anything else for plant
hairs, it is, nevertheless, worth while to call attention to some of
the mistakes that are liable to be made. In works on systematic
botany sometimes occur contradictory statements concerning the
abundance or scarcity of hairs, especially as they relate to the
flower. In a superficial examination, for instance, in the violets,
large masses of germinating pollen grains with their tubes matted
together are not at all uncommon in the throat of the corolla, and
these have been mistaken for hairs. Furthermore, the mycelia
of fungi may be mistaken for hairs, especially in young seedlings,
as of hyoscyamus, belladonna, etc., where thread-like delicate
branching hairs may occur. In the examination of economic prod-
ucts, especially powdered drugs and spices, mistakes of this kind
may occur, unless the student has devoted some attention to this
study. In all studies of plant hairs the student should carefully
locate the summits and bases, and unless these can be recognized,
or if broken made to correspond to each other, one cannot say
that hairs are present.

CORK CELLS replace the epidermal cells of roots and stems that
persist year after year. They are formed, as has already been
stated, from a distinct meristem, called the phellogen. Cork cells
differ from the epidermal cells in that the walls are uniformly
thickened and on surface view are polygonal in shape. The walls
consist of suberin, a substance allied to cutin ; in some instances
they also contan lignocellulose, forming cork stone-cells, as in
asclepias and calumba. The young cells may contain a thin layer
of cytoplasm and a nucleus ; they usually also contain brownish
masses of tannin or tannin-like compounds, and occasionally crys-
tals of cerin or calcium oxalate.

CELL-CONTENTS AND FORMS OF CELLS. 291

Cork not only occurs as a secondary protective layer, but may
also arise in other parts of the plant as a result of injury, as in
leaves, fruits, stems, and tubers. It also arises as a result of the
disarticulation of the leaf in autumn.

PERIDERM. — The epidermis is not adapted for the protection
of the perennial plant organs on account of its thin, frequently
delicate structure and its inability to continue with the increase in
thickness of stems and roots. Hence it becomes replaced by the
periderm, which consists of a lasting tissue, the CORK, and of a
meristematic tissue, the PHELLOGEN, which reproduces the cork
when it becomes torn or destroyed, by the continued growth in

FIG. 156. Section through a secondary lenticel in the bark of Sassafras; e, epidermis:,
st, stone cells; phel, phelloderm derived from secondary phellogen and having thick ligni-
fied wall; p, parenchyma; c, cork; com, complementary cells. — After Weiss.

thickness of stems or roots. Cork is not only of sub-epidermal
origin, but may occur deeper in the cortex (Fig. 158), or even in-
side the endodermis. In the latter case, as in roots, it owes its;
existence to the activity of the pericambium. Superficial, i.e.,.
hypodermal cork, is extremely rare in roots. Not infrequently a
layer of cells is formed inside of the phellogen, being termed the
phelloderm. They usually contain plastids ; the walls are moder-
ately thick and free from intercellular spaces (Fig. 156).

Lenticels may be described as biconvex fissures in the periderm
which permit of the easy access of air to the intercellular spaces
of the rather loosely arranged cells lying beneath them (Fig.

292 A TEXT-BOOK OF BOTANY.

156). They usually arise as the product of a meristem situated
beneath the stomata of the epidermis, the stomata being replaced
by them when cork is developed. Several types of lenticels are

FIG. 157. Bark of Rhamnus Purshiana showing large whitish patches of lichens,
and numerous lens-shaped lenticels,

distinguished. They are quite characteristic and prominent in
a number of barks, as those of species of Betula, Prunus, Rham-
nus (Fig. 157), etc.

CELL-CONTENTS AND FORMS OF CELLS. 293

FIG. 158. Development of Cork: A, in epidermal cells of stem of Oleander; B,
development of cork in upper row of collenchymatous cells in the stem of Sambucus nigra;
C, development of cork meristem in cells of cortex immediately above the primary bast
fibers in Rubus fruticosus; D, development of primary cork in cells above the secondary
bast fibers of Clematis Vitalba; e, epidermal cells; k, cork; km, cork-meristem ; c, collen-
chyma; b, parenchyma; b, b, primary bast fibers; b', secondary bast fibers; K, young
cork cells, — After Dippel in "Das Mikroskop."

BORK. — The cork cambium or phellogen develops before ma-
turity in the green stems of woody plants belonging to the dico-
tyledons. It may develop in the primary or secondary tissues

294

A TEXT-BOOK OF BOTANY.

(Fig. 158). When the phellogen develops in the deep-seated
tissues, the cells outside of the corky layer sooner or later die and
slough off. This is due to the fact that the cork cells are suberized
and do not permit the passage of the cell-sap containing food sub-
stances. In large shrubs and trees with thick stems and trunks

FIG. 159. Development of Bork: A, in bark of cherry (Prunus Cerasus), showing
a layer of periderm (k) with thin-walled cork cells; bast fibers (Bf); parenchyma (p);
stone cells (st) occasionally branching and lengthened into fibers. B, inner layer of periderm
of Quercus Robur, showing compactly arranged, thick-walled cork cells (P) filled with a
reddish phlobaphene or altered tannin; starch-bearing parenchyma (p); stone cells (st);
sieve tubes (Bg) ; bast fibers (Bf) ; prism of calcium oxalate (kr) ; several rows of thick-
walled, porous cells (x). — After Dippel in "Das Mikroskop."

a number of successive layers of cork or periderm are formed.
These layers with the dead cortical tissues between them persist
to some extent and constitute what is known as bork, i.e., bork
consists of a number of alternate layers of periderm and cortical

CELL-CONTENTS AND FORMS OF CELLS. 295

tissues. The cork cells in different trees are variously developed
and accordingly two types of bork formation may be distinguished.
In sycamore, cherry and plum trees the cork cells are only slightly
thickened (Fig. 159) and the periderm in the form of layers

FIG. 160. White oak bark with the fissured corky layers (bork).

separates from the tree annually. In the oaks, chestnuts and
tulip poplar the cork cells (Fig. 159) are thick walled and com-
pactly arranged so that, under the stress of growth and thickness
of the bark, the layers of periderm are split longitudinally, giving

296 A TEXT-BOOK OF BOTANY.

rise to the deep furrows (Fig. 160) which are so characteristic
of the outer surface of our large trees.

Laticiferous or milk tissue occurs in all those plants which
emit a milk- juice on being cut or otherwise wounded. The juice
may be colorless, as in the oleander; whitish, as in the Asclepia-
daceae, Apocynaceae, etc. ; or yellowish, as in the Papaveracese.
It contains caoutchouc, oils, resins, mucilage, starch, calcium
oxalate and alkaloids as well. The walls are relatively thin and
consist chiefly of cellulose. The tissue consists either of single
cells of definite length, as in the Papaveracese, or the cells may be
of indefinite length, as in the Asclepiadacese, or it may consist of
a more or less branching network (Fig. 127) formed by the
anastomosing of a number of cells, as in Taraxacum (consult
paragraph on Latex, pp. 238-241).

As has already been stated, the latex of plants contains a num-
ber of plastic or trophic substances, — i.e., those which, either at
once or after being stored for a time as reserve food, are drawn
into metabolism and serve as nutrient material. They also con-
tain a number of aplastic or non-trophic substances, as caoutchouc,
resin, alkaloids, volatile oils and tannin, which are in the nature
of metabolic by-products and are incapable of further metabolism.
While it is highly probable that the laticiferous tissue, on account
of its being always associated with the phloem, functions to some
extent for the transportation o>f plastic substances, yet it serves
another purpose, viz., to protect the underlying cells after injury
of the plant by insects or'herbivorous animals. This protection
results from the rapid coagulation of the exuding latex upon
exposure to the air and forming a varnish-like surface. In some
cases the latex contains a poisonous principle which exercises a
protective function. In Rhus Toxicodendron the principle causing
the eczema, namely toxicodendrol, is supposed to be formed in
laticiferous tissues being transferred to the hairs, which upon
being broken liberate the poison.

CELL-CONTENTS AND FORMS OF CELLS. 297

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CHAPTER III

THE OUTER AND INNER MORPHOLOGY OF
HIGHER PLANTS.

INTRODUCTORY.

IT may be well to repeat at this point that on germination of
the megaspore the female gametophyte bearing the egg-cell is
formed, and that on germination of a microspore the male gameto-
phyte bearing male nuclei is organized. The union of egg-cell
and a male nucleus gives rise to the sporophyte embryo contained
in the seed, which develops into the plant we see, namely, the
sporophyte. The female gametophyte always remains concealed
within the embryo-sac, and the male gametophyte may be said to
embody the protoplasmic contents of the pollen tube.

A complete flower is made up of floral leaves and sporophylls,
the latter being essential for the reason that they give rise to the
spores. While the flower belongs to the sporophyte generation,
the propagative organs may be said to be derived from both the
sporophyte and gametophyte, and hence may be distinguished as
asexual and sexual. The following outline illustrates their
derivation :

Propagative
Organs

Sexual, derived from
gametophytes (sex-
ual generation)

Egg-apparatus,

containing egg-cell
female gamete

or

Asexual, derived from
sporophyte (asex-
ual generation)

298

Male Generative-cell,
giving rise to male
nuclei or male gametes

Microsporangium (pollen
sacs) giving rise to
microspores (pollen
grains)

Megasporangium (nucel-
lus) giving rise to mega-
spore (embryo- sac)

MORPHOLOGY OF HIGHER PLANTS.

299

The vegetative organs comprise the root and shoot, the latter
being usually differentiated into shoot axis or stem, and leaves.
The usual type of shoot is one which bears leaves and is exposed
to the light. The work of carbon dioxide assimilation (photosyn-
thesis) being carried on for the most part by the leaves, the axis
is sometimes spoken of as the " assimilation shoot."

FIG. 161. A, advanced stage of germination of the common garden pea (Pis-urn sa-
tivum) showing growing point of root protected by root-cap (p); root branches or second-
ary roots (rb) ; hypocotyl (he) ; epicotyl or stem above the cotyledons (ec) ; cotyledons
(one in view) (c). B, plantlet of white or yellow mustard (binapis alba) show;ng copious
development of root- hairs (h).

I. OUTER MORPHOLOGY OF THE ROOT.

THE ROOT, or descending axis of the plant, normally pene-
trates the soil, absorbing inorganic substances in solution and act-
ing as an anchor and support for the shoot. True roots are found
only among plants having a vascular system, as the Spermophytes
and the higher Pteridophytes, although, on the other hand, some
of the higher plants do not possess them, as certain of the sapro-
phytic orchids and some of the aquatic plants as Utricularia,

300

A TEXT-BOOK OF BOTANY.

Lemna, etc. If we take a germinating plant and mark the root
into ten equal divisions, beginning at the apex, and place the
plant in a moist chamber, it will be found in the course of one
or two days that the marks between I and 5 have become much

FIG. 162. Longitudinal section through the tip of the root of Indian corn (Zea Mays)
showing root-cap: a, outer layer; i, inner layer. — After Sachs.

farther apart, and that the growth in this region is about three
times that between 5 and 10. This experiment indicates that the
growth of the root takes place at or near the apex, this region
being known as the point of growth, or point of vegetation (Fig.
162).

MORPHOLOGY OF HIGHER PLANTS. 301

Upon examining the tip of a very young root by means of the
microscope, it will be seen that the growing point is protected by
a cup-shaped body of a more or less solid structure and frequently
mucilaginous; this is known as a ROOT-CAP. Its function is to
protect the growing point, and it exists in all roots of terrestrial,
epiphytic, and aquatic plants except the parasites.

Just above the root-cap there is developed a narrow zone of
delicate hairs, which arise from the surface cells and are usually
thin-walled and unicellular. These are known as ROOT-HAIRS
(Fig. 161, B) and their function is twofold: (i) They secrete an
acid which renders the inorganic substances of the earth soluble,
and (2) they absorb these and other substances for the nourish-
ment of the plant. It should be stated that there are a number of
plants which for various reasons do not possess root-hairs, such
as water-plants, marsh-plants, certain Coniferae, Ericaceae, etc.

When the primary root persists (as in Gymnosperms and
Dicotyledons) it increases considerably in length and becomes
ramified ; if, at the same time, it increases in thickness, and much
more so than its branches, then it is called a TAP-ROOT (as in
Dancus Beta, etc.).

In the vascular cryptogams (Pteridophytes) and the monocoty-
ledons the primary root is generally thin and weak, frequently
but little ramified, and disappears at an early stage, being re-
placed by SECONDARY ROOTS, as in Zea. Secondary roots may
arise not only upon the stem but even upon leaves, as in Begonia
and Bryophyllum. The term LATERAL ROOTS is restricted to those
that develop from the root alone.

The development of roots upon shoots or of so-called " AD-
VENTITIOUS ROOTS " occurs in nearly all of the woody plants of
the Spermophyta. Many annual herbaceous plants do not possess
this capacity at all. The adventitious roots arise from " root-
primordia " which are formed under the cortex of the shoots.
While ordinarily they do not develop upon the shoots, yet if
cuttings are made, as of Coleus, Geranium, Rosa, etc., we find
" either singly or on both sides of the axillary buds " the develop-
ment of adventitious roots from the latent root-primordia.

Influence of Gravity. — The root is popularly supposed to
grow downward, in order to avoid the light. On the other hand.

302

A TEXT-BOOK OF BOTANY.

the theory has been established (as a result of Knight's experi-
ments) that the root. grows downward by reason of the influence
of gravity. In addition it may be said that the principal functions
of the root, namely, those of absorbing inorganic food materials
and of fixing the plant to the soil, determine in a measure the
direction of its growth. The tendency of the root to grow down-
ward is a characteristic which distinguishes it from other parts
of the plant, and it is said to be POSITIVELY GEOTROPIC (Fig. 163,
A).

FIG. 163. A, seedling of Brassica nigra in which root and stem have curved into a
vertical position after being laid horizontally. B, seedling of Sinapis alba, the hypocotyl
showing a positive, the root in water a negative heliotropic curvature. The arrows show
the direction of the incident rays of light. — After Pfeffer.

The influence which gravity has on plants may be best under-
stood by bearing in mind that gravity is a constant force which
acts perpendicularly to the surface of the earth, and that all parts
of the plant are subject to its influence. The organs of plants
respond in different ways to the action of gravity, but a clear
distinction should be made between mere mass attraction, or that
manifestation of the force of gravity whereby the heavily laden
branch of a fruit tree bends downward, and the stimulus which
causes the primary root of a plant to grow downward and the
shoot to grow upward. While all parts of the plant are subject
to the influence of gravity, not all the organs of plants respond
in an equal degree. This is well illustrated by roots themselves.

MORPHOLOGY OF HIGHER PLANTS. 303

It is well known that, whatever the position of the seed at the
time of germination, the young radicle begins to grow perpen-
dicularly downward ( Fig. 163, A ) . The branches, however, which
arise on the primary root are less positively geotropic and, instead
of growing downward parallel with the primary or tap root, di-
verge at an angle from it (Fig. 161 ) . The secondary branches are
still less affected by gravity and diverge still more from the per-
pendicular, or grow out horizontally, while still others do not

FIG. 164. Over-turned tree trunk showing spreading root-system, the main or
tap root having died away

appear to be in the least affected by gravity and grow freely in any
direction. In the case of large trees we frequently find that the
lateral roots spread out in a more or less horizontal plane near the
surface of the earth, and if the main root has died the influence of
gravity is not very evident (Fig. 164). But here it must be re-
membered that gravity was instrumental in determining the direc-
tion of growth at an earlier stage. This spreading of the roots
near the surface of the earth is of decided advantage to plants, for
it enables them to avail themselves of the better soil of the surface

304

A TEXT-BOOK OF BOTANY.

layers. As indicated, gravity also determines the upward perpen-
dicular direction of the shoot, which is therefore said to be
NEGATIVELY GEOTROPic, but, as in the case of the root, the branches
are less influenced by it and hence diverge at various angles from
the main axis.

Some of the other effects of gravity may be noted. If the end
of a shoot be cut off, the branches next to the top will grow per-

FIG. 165. Mangr6*ve forest (Rhizophora Mangle), showing the habit of growth, es-
pecially the numerous aerial roots which form an almost impenetrable thicket. The man-
grove is common along the southern shores of Florida, in the Bahama Islands, and in the
West Indies. Many shellfish, lobsters, and other forms of sea life are often found clinging
or attached far up on the roots where they become lodged during high tides. — Photograph
from article by Henry Trimble on Mangrove Tannin in Contributions from the Botanical
Laboratory of the University of Pennsylvania, 1892, p. 50.

pendicularly upward and thus assume the work of the main axis.
Likewise in the case of roots, if the apex of the main or tap root
be cut off, the branches near the end will assume a perpendicular
direction. It will frequently be noticed in the case of trees which
have been uprooted or where branches have been bent over hori-
zontally that the new branches which arise grow perpendicularly
upward. Creeping shoots furnish another good example showing

MORPHOLOGY OF HIGHER PLANTS.

305

FIG. 166. Tuberous root of Ginseng (Panax quinquefolium) . The root on the left is a
fresh specimen and was grown in the United States. The one to the right was purchased at
a Chinese bazaar. It is translucent, of a yellowish-brown color, and has the characteristic
shape and markings considered desirable by the Chinese. The markings on the upper
segment of the specimen are stem scars which are usually found on old roots. The trans-
lucent appearance is no doubt due to the manner of treatment. While the method is not
generally known, similar specimens may be prepared by treating the recently gathered
roots with freshly slaked lime.

the influence of gravity, the branches growing upward and the
roots downward.

The root exerts a certain amount of upward pressure on the
liquids in the stem. This fact can be demonstrated by cutting off
20

306 A TEXT-BOOK OF BOTANY.

the stem just above the surface of the earth and attaching thereto
a glass tube by means of a tightly-fitting rubber tube. It is de-
sirable to perform this part of the operation under water and to
have the glass tube partly filled with water at the beginning of
the experiment. This is done to prevent the clogging up of the
vessels with air, which prevents the ready passage of fluids
through them. If the root is now kept moist, the osmotic pressure
of its cells forces water up into the glass tube, sometimes to a
height of several feet. Experiments on the begonia and on many
other plants succeed very well, but for some reason the geranium
is impracticable to work with. The manometer devised by Ganong,
while not showing the quantity of water forced up by the root,
shows the amount of pressure exerted, which is really the most
important fact to be ascertained.

Modified Roots. — Roots which arise from the nodes of the
stem or other parts of the plant are known as secondary or adventi-
tious roots. These include the aerial roots of the banyan tree
and the Mangrove (Fig. 165), which are for the purpose of sup-
port ; the roots of the ivy, which are both for support and climb-
ing, and the roots of Indian corn and many palms which serve both
for support and the absorption of nourishment. Under this head
may also be included the aerial roots of orchids and the root-like
structures, or haustoria, of parasites, as of mistletoe and dodder,
which penetrate the tissues of their host plants and whose vascular
strands come into most intimate relations with those of hosts.

Of special interest also are the breathing roots of certain
marsh-plants which serve to convey oxygen to the submerged
parts ; and the assimilation roots of certain water-plants and
epiphytes, which are unique in that they produce chlorophyll.
In certain plants the roots give rise to adventitious shoots, as in
Prunus, Rubus, Ailanthus, etc., and in this way these plants some-
times form small groves.

Root Tubercles. — The roots of the plants belonging to the
Leguminosse are characterized by the production of tubercles,
nodules or swellings (Fig. 167) which have been shown to have
a direct relation to the assimilation of nitrogen by the plants of
this family. Like carbon, nitrogen is one of the elements essential
to plant-life, being one of the constituents of protoplasm and

MORPHOLOGY OF HIGHER PLANTS.

307

present in various nitrogenous (protein) compounds which occur
as normal constituents of the plant. The nitrogen required by
plants is derived either from nitrogen salts contained in the soil,
as nitrates and ammonium salts, or from the free nitrogen of
the atmosphere. While most of the higher plants are able to
assimilate nitrogen compounds existing in the soil, only the
Leguminosse and Aristolochiaceae, with possibly a few exceptions,
are able to assimilate atmospheric nitrogen, and in this respect the

FIG. 167. Root tubercles on Lupinus, one of the Leguminosoe: A, roots with tubercles;
B, transverse section of root showing the cells (b) which contain the nitrogen bacteria. —
A. after Taubert; B, after Frank.

majority of the Leguminosae stand as a class by themselves.
Apparently in direct relation to this character stands the fact that
the seeds of these plants contain a high percentage of nitrogen.
This special ability of the Leguminosae to fix atmospheric nitrogen
in the plants depends upon the presence of the nodules, which are
due to the infection of the roots by a soil-bacterium (Pseudomonas
radicicola) , although the precise mode of fixing the nitrogen is

3o8 A TEXT-BOOK OF BOTANY.

not known. The bacteria seem to be localized in the nodules and
are not found in any other part of the plant.

It has been shown that when the roots of leguminous plants
are free from nodules they do not have the power of assimilating
free nitrogen. On the other hand, when the nodules produced by
the bacteria are developed, the plants will grow in soil practically
free from nitrogen salts. Because of this power the plants of this
family are useful in restoring worn-out land, i.e., land in which

FIG. 168. Transverse section of a root bearing root hairs; the latter are thin walled,
irregularly bent, and attached at various places to small particles of soil. The hairs secrete
an acid, rendering the inorganic substances soluble, which are then diffused through the
walls of the hairs, transmitted to the cortical parenchyma and distributed through the
conducting cells of the xylem to the shoot. — After Frank.

the supply of nitrogen is exhausted, and they thus play an impor-
tant role in agricultural pursuits.

The enriching of the soil is accomplished by ploughing under
the leguminous crops, as of clover or alfalfa, or allowing the
nodule-producing roots to decay, when the nitrogen compounds
are distributed in the soil.

(Consult Bulletins on " Soil Inoculation for Legumes," issued
by the Bureau of Plant Industry, U. S. Department of Agri-
culture.)

MORPHOLOGY OF HIGHER PLANTS. 309

THE INNER STRUCTURE OF THE ROOT.

Primary Structure. — If we make a transverse section of the
young portion of a root (Vascular Cryptogam, Gymnosperm, or
Phenogam), we notice the following tissues (Figs. 169-174).
The outermost tissue is EPIDERMIS (E), it being generally thin-
walled and destitute of cuticle ; it is, as a rule, hairy, and these
hairs, which are relatively long, but always unicellular, are known
as ROOT-HAIRS (Figs. 161, 1 68) ; they ramify but very seldom.
Inside the epidermis there is frequently present a HYPODERMIS

FIG. 169. Radial vascular bundle in root of Allium ascalonicum, showing a large
central trachea from which radiate five small groups of tracheae and between which are the
groups of leptome or sieve; p, layer of pericambium or pericycle; d, transition cells or pas-
sage cells in the endodermal layer, and which permit the easy transfer of substances between
the cortical parenchyma and the tracheae of the stele. — After Haberlandt.

(sometimes referred to as an EXODERMIS) composed of a single
layer of cells or, at the most, of but several layers, the cells of
which differ in shape and size from those of the epidermis and the
adjoining cortical parenchyma. The hypodermis takes the place of
the epidermis when the latter is worn off, except in the few cases
where hypodermal cork becomes developed, as in Cephalanthus,
Solidago, and in the Bignoniaceae.

The root bark is composed of parenchymatous cells, being

3io A TEXT-BOOK OF BOTANY.

commonly referred to as the CORTEX, and is either homogeneous
or divided into two zones, the outer or peripheral being composed
of thick-walled cells which naturally belong to the hypodermis
and an inner or internal strata made up of thin-walled cells. The
cells of the cortical parenchyma may contain starch, calcium
.oxalate, calcium carbonate, and there may be associated with them

FIG. 170. Cross-section of the primary root of a germinating plant of Phaseolus
multiflorus, showing development of* secondary structures: p, group of primary vessels;
g, larger tracheae of secondary development formed between the four primary strands of
xylem; b, the four groups of phloem alternating with the four initial groups of xylem and
beneath which secondary tracheae are forming (g'); pc, pericambium (pericycle), a layer of
cells beneath the endodermis (s). A few layers of cortical parenchyma are shown outside
of the endodermis. In the middle is a well-developed pith (M) which sometimes is developed
in roots. — After Sachs.

secretory cells or receptacles. Immediately beneath the innermost
layer of cortical parenchyma is a distinct layer of cells usually
considered part of the cortex and known as the ENDODERMIS. It
consists always of a single layer of cells, without any intercellular
spaces, and the radial walls show in transverse section Casparyan
spots,1 depending upon a local folding of the cell- wall, which is
here suberized. In the course of time the cell-walls of the en-

1 " Physiologische Pflanzenanatomie," by Dr. G. Haberlandt, p. 245.

MORPHOLOGY OF HIGHER PLANTS. 311

dodermis frequently become thickened, either all around, or only
on the inner or radial walls, so that we might speak of an O-
endodermis as in Honduras sarsaparilla or an U-endodermis as
in Mexican sarsaparilla, according to the manner of thickening.

FIG. 171. Cimicifuga. Transverse section of the central part of a mature root in
which the secondary changes are completed: a, parenchyma of primary cortex; b, endo-
dermis; c, cambium zone; d, tracheae in secondary xylem; e, broad, wedge-shaped medullary
ray; f, outer portion of one of the primary xylem bundles; g, pericycle-parenchyma beneath
the endodermis; h, inter-fascicular cambium. — After Bastin.

This is especially the case in the monocotyledons where the walls
of the endodermal cells become completely suberized and im-
permeable to water. In some roots the cells of the endodermis
may be uniformly thick-walled throughout, while in others some

3i2 A TEXT-BOOK OF BOTANY.

of the cells- may remain thin-walled, and these cells, the so-called
" transition cells " or " passage cells," form channels of com-
munication between the cortical parenchyma and the vessels of
the stele (Fig. 169) ; they are therefore located just outside the
peripheral vessels of each ray of the xylem (or hadrome).

Inside the endodermis is the STELE, formerly called the central-
cylinder. In this the peripheral stratum, sometimes composed of
two or three layers of cells, represents the PERICAMBIUM (or
PERICYCLE). The cells are generally thin-walled, and in Dicotyle-
dons and Gymnosperms are able by cell-division to form cork and

RB

FIG. 172. A transverse section through the root of a germinating pea-plant (Pisum)
about 40 mm. from the tip, showing the origin of a root-branch (RB); E, epidermis; C, pri-
mary cortex; X, hadrome (vessels); P, leptome (sieve); EN, endodermis.

secondary cortex, but in all vascular plants it is capable of giving
rise to "lateral branches" or "lateral roots" (Figs. 161, 172),
hence it is frequently referred to as the " RHIZOGENOUS LAYER/'

Inside the pericambium (by some authors compared with the
pericycle of the stem) we find strands of phloem (or leptome)
(P) alternating radially with a corresponding number of strands
of xylem (or hadrome) (X). The number of these strands vary
in the different groups of plants (Figs. 169-174), being highest in
the monocotyledons where a pith is developed, as in sarsaparilla,
several grasses, palms, etc. This peculiar arrangement of the

MORPHOLOGY OF HIGHER PLANTS. 313

phloem and xylem, as separate strands alternating with each other
and not being located, as in stems, in the same radii, has given
rise to several adverse views. Some authors have considered
the root-stele as one single mestome-strand (or fib ro vascular
strand), while others, especially of recent date, consider it to be
composed of several MESTOME STRANDS.

The xylem or hadrome contains tracheae or vessels, the periph-
eral being spiral and narrower than the inner, which are scalari-
form or reticulate. The tissue in the center of the stele in mono-
cotyledons is not uncommonly made up of parenchyma cells, and

FIG. 173. Primary structure in the root. Transverse section of root of pea (Pisum)
about 40 mm. from the root-cap: H, epidermal cells, some of which are developed into
root-hairs; C, primary cortex; EN, endodermis; PC, pericambium; X, hadrome, composed
of tracheae; P, leptome, composed of sieve cells, the hadrome (vessels) and leptome (sieve)
forming a triarch radial fibrovascular bundle.

corresponds exactly with the pith of the stem. In roots it is often
called CONJUNCTIVE TISSUE, and the cells may contain starch and
crystals of calcium oxalate.

Secondary Structure. — In roots that are able to increase in
thickness (as in Gymnosperms and Dicotyledons), the increase
depends upon the activity in the pericambium, some of the cells
becoming meristematic. These meristematic cells are known as
phellogen, developing cork outwardly and secondary cortex in-
wardly. The meristem of the stele or cambium also becomes very
active and develops on the inner face of the phloem and extends

A TEXT-BOOK OF BOTANY.

from there to the outside of the peripheral vessels of the xylem
(Fig. 174) ; thus a continuous cambial zone gradually arises.
From this zone secondary tracheae or vessels become developed on
the inner face of the primary phloem, while secondary phloem
becomes differentiated outside the primary rays of xylem ; or
only parenchyma develops outside the primary xylem, resulting in

sx

FIG. 174. Section in the older part, higher up on the root of pea (Pisum), showing in
addition to what has been observed in Fig. 1 73, the beginning of the change from primary to
secondary structure: CA, the development of a cambium; SX, secondary hadrome (or
vessels), and SP, secondary leptome (or sieve).

the formation of secondary PARENCHYMA-RAYS (or medullary
rays). In other words, the original radial structure of the stele
changes to the collateral type (Fig. 175). Owing to this increase
within the stele, the peripheral tissues from the endodermis to the
epidermis naturally become broken and are subsequently thrown
off, but are replaced by the pericambial cork and secondary cor-
tex derived from the pericambium. The older roots, then, of
Gymnosperms and Dicotyledons thus resemble the structure of
stems, except that no pith exists in these roots, at least not usually.

MORPHOLOGY OF HIGHER PLANTS. 315

Some differences are, however, quite noticeable in some instances,
as in the thick roots of Beta, Radish, etc., where the wood paren-

M

FIG. 175. Fully developed secondary structure in root. Transverse section of root
of pea (Pisurn) at the end of the summer's growth: E, some epidermal cells with fragments
of root-hairs; C, primary cortex; EN, endodermis; K, pericambial cork; B, bast fibers;
SC, secondary cortex; S, sieve; T, tracheae; W, wood fibers; WP, wood parenchyma;
M, medullary rays; the tracheae (or vessels) and leptome (or sieve) forming open collateral
fibrovascular bundles, these being found in dicotyledons with but few exceptions.

chyma is usually abundant, thin-walled, and not lignified, the
annual rings also being mostly indistinct.

The characteristic distinguishing the primary and secondary

A TEXT-BOOK OF BOTANY

-1?

FIG. 176. Glycyrrhiza: A, transverse section; B, longitudinal section. B, bark;
H, wood; X, cambium zone; ph, cork cells; rp, cortex; p, parenchyma; k, crystal fibers;
s, sclerenchyma fibers, including wood fibers occurring in the wood and bast fibers present
in the bark; t, tracheae; m, medullary rays. — After Meyer.

MORPHOLOGY OF HIGHER PLANTS.

317

structures of dicotyledonous roots may be summarized as follows :

PRIMARY STRUCTURE: Epidermis and root-hairs. Hypoder-
mis. Primary cortex consisting of parenchyma. Endodermis,
pericambium, xylem arranged in radial rays which alternate
with phloem or sieve strands, constituting a radial fibrovascular
bundle (Figs. 169-174).

SECONDARY STRUCTURE: Cork cells, phellogen, secondary cor-
tex consisting of parenchyma. Phloem, cambium, and xylem
arranged in radial groups, forming open collateral fibrovascular
bundles. Medullary rays separating the fibrovascular bundles
(Figs. 175-177).

Sometimes, as in glycyrrhiza and valerian, a number of paren-
chyma cells are found in the center of the root, these constituting
the PITH (Fig. 176) or medulla; but they are usually wanting in
dicotyledonous roots.

Wood and bark are terms used to distinguish those portions
of the root or stem separated by the cambium; all that portion
inside of the cambium, including xylem, medullary rays, and
pith, being known as the WOOD. The BARK includes the hadrome,
the medullary rays outside of the cambium, and the tissues formed
by the phellogen, vis., secondary cortical tissue and cork.

The following diagram of the secondary structure of a dicoty-
ledonous root may be of assistance in understanding the origin
and relation of the tissues comprising it :

Wood made up of

Cambium produces

Bark made up of

f Pith, which may be wanting.

J f Composed of vessels, wood parenchy-

\ ma and wood fibers ; or tracheids may
Xylem. . J replace these cells, or be associated
* with them. These are arranged in
groups forming radial rows which
are separated by medullary rays.

Phloem . .

Consisting of leptome and companion
cells; bast fibers may also be present.
These are arranged in collateral
groups and form radial rows which
are separated by medullary rays.

Meristem of pericambium producing pericambial-
cork and parenchyma. Phellogen later forming
periderm in stems several years old, and borlk
in the trunk of large shrubs and trees.

A TEXT-BOOK OF BOTANY.

FIG. 177. A, transverse section of Phytolacca root, showing the fibrovascular bundles
(V, V, V",) which are produced by distinct cambiums (C). The parenchyma contains little
starch, and some of the cells (R) show short raphides of calcium oxalate, many of the crystals
being distributed in the section.

B. Transverse section of Belladonna root which is two or three years old. There is but
one cambium zone (C) . Most of the parenchyma contains starch (St) , the remaining cells
containing cryptocrystalline crystals of calcium oxalate.

K. cork; S, sieve; W. wood fibers and T, tracheae, both of which are strongly lignified in
Belladonna root; M. medullary rays.

MORPHOLOGY OF HIGHER PLANTS. 319

The root branches arise as the result of the development of
primary meristems in the pericambium (Figs. 161, 172). The
tissues forming the branches are directly connected with the
fibrovascular tissues of the root and protrude through the over-
lying tissues without having any connection with them. The
structure of the branches thus formed corresponds to the primary
structure of the roots, and in the case of dicotyledonous roots
may also subsequently develop a secondary structure. Goebel
states that in plants which grow in moist soil, or whose roots func-
tion only for a short time, the branches may be altogether sup-
pressed, as in Colchicum, Arissema, etc.

Contraction of roots is observed in both monocotyledons
and dicotyledons, it being most apparent in the former, as in the
roots of Veratrum viride (Fig. 178). The uneven or corkscrew-
like appearance is due to a contraction, which arises as follows :
Some of the longitudinally elongated cells beneath the epidermis,
as well as cells extending to and including the endodermis, absorb
large quantities of water, which causes them to assume a spherical
form (as the cells of a potato are altered on boiling), the result
being a longitudinal contraction of the root at this point. In this
way the plant is fastened more securely to the earth, and at the
end of the season's growth the apical buds of plants, with upright
rhizomes, as of Veratrum viride, Dracontium, etc., are drawn
into the earth and thus protected during the winter season.

Abnormal Structure of Roots. — It is often difficult to recog-
nize the type-structure of dicotyledonous roots in drugs, owing
to the anomalous and abnormal secondary structure. Scleren-
chymatous fibers, while present in glycyrrhiza (Fig. 176) and
althaea, are not infrequently wanting. Wood fibers may be spar-
ingly developed, as in young belladonna roots (Fig. 177), or even
wanting, as in gentian. In other cases the medullary rays are
abnormal, being replaced in calumba by wood parenchyma, and
in ipecac and taraxacum by sclerenchymatous cells. In asclepias
and calumba a layer of stone cells occurs near the periphery ; in
gelsemium sieve cells develop in the xylem ; in senega the xylem is
not uniformly developed, and in still other cases, as in jalap,
pareira, and phytolacca (Fig. 177, A), successive cambiums de-
velop, producing concentric series of open collateral fibrovascular
bundles.

320 A TEXT-BOOK OF BOTANY.

II. THE OUTER MORPHOLOGY OF THE STEM.

The stem, or ascending axis of the plant, usually grows in a
direction opposite to that of the root, seeking the light and air.
The tendency of the stem to grow upward is characteristic of
the majority of plants, and is spoken of as NEGATIVE GEOTROPISM.
The growing point of the stem is at the apex, and it is protected
by a layer of bud scales (Fig. 179, B).

FIG. 178. Longitudinal section through a root of Veratrum viride showing the nature
of the contraction of the root: E, epidermis; CS, cells of cortex containing starch; CO,
cells of cortex containing raphides; F, fibro vascular bundle; A, rifts or cavities formed as
a result of the radial swelling of the cells of the cortex.

Stems are further characterized by bearing leaves, or modi-
fications of them. The leaves occur at regular intervals in the
same species, and that portion of the stem from which they arise
is spoken of as a NODE, while the intervening portion is called an
internode.

Stem branches usually arise in the axils of the leaves, first

MORPHOLOGY OF HIGHER PLANTS.

321

appearing as little protuberances, sometimes spoken of as pri-
mordia, on the stem. Their origin differs from that of the root
branches, in that they arise from meristematic or embryonic tissue
developed just beneath the epidermis. The branches, like the
main axis, manifest negative geotropism, although to a lesser
degree. They likewise possess a growing point at the apex,
covered with embryonic leaves (Fig. 179). Not infrequently
more than one branch arises in the leaf axil.

Buds may be defined as undeveloped shoots in which the
foliage is yet rudimentary. The buds at the ends of stems or

~P

FIG. 179. A, longitudinal section through the apical region of the stem of the embryo
of a bean (Phaseolus multiftorus) ; ss, apex; pb, parts of the two first leaves, and their
axillary buds (k, k,); r, periblem or primary cortex. B, diagram of longitudinal section
through winter bud of Quercus coccinea: P, growing point; L, young leaves; SB, stem
branches; F, fibro vascular bundle. — A, after Sachs.

branches are known as APICAL, or TERMINAL BUDS, and those situ-
ated in the axils of the leaves, as AXILLARY BUDS. In some cases
they are protected by scales, as in hickory, when they are known as
scaly buds; while buds which are not thus protected are called
naked buds. They are further distinguished as leaf, flower, and
mixed buds, as they develop into leaves or flowers, or both.

We have to distinguish between overground shoots and under-
ground shoots. The former are sometimes designated as epi-
geous (upon the earth) and the latter as hypogeous (under the
earth).

21

322

A TEXT-BOOK OF BOTANY.

Epigeous Shoots. — As would be supposed, these two kinds
of shoots vary to a certain extent. In epigeous shoots a number
of features may be noted. If the internodes are long the leaves
do not usually interfere with one another so far as exposure to
light is concerned, but if the internodes are short, the leaves are
all brought close together on the axis, and hence, were it not for

PIG. 180. A, woody vine of Canada moonseed (Menispermum canadense) , which ascends

by twining to the right.
B, stem of wild yamroot (Dioscorea mllosa), which ascends by twining to the left

and several of the characteristic 3-winged capsules at the top.

The twining movements of stem climbers are due to the stimulus of gravity rather
than to contact stimulus, and in the majority of twining plants the revolving movements,
as seen from the side, are from the left to the right, i.e., in a direction opposite to that of
the hands of a watch if represented diagrammatically.

various modifications, their relation to light would be very un-
equal. Sometimes the shoot-axis may share with the leaves the
work of assimilation, as in the case of certain green stems. Then
again there are cases in which the leaves are reduced, and the
work of assimilation is carried on exclusively by the shoot-axis,
as in most Cactaceae, certain marsh-plants, and others. On the

MORPHOLOGY OF HIGHER PLANTS.

323

other hand, the shoot-axis may be modified so as to increase the
assimilating surface, as by a flattening of the axis, as in some of
the Cacti, the leaves being suppressed or considerably reduced.

FlG. 181. Bryonia dioica. a, young, spirally coiled tendril; b, expanded and irritable
tendril; c, tendril which has grasped a support; d, tendril which has not grasped a sup-
port, and has undergone the old-age coiling. — After Pfeffer.

Branches are not infrequently modified to hard, pointed, and
spiny structures, as in the Japanese quince, when they are spoken
of as thorns. Leaves and even flowers may arise upon thorns,
which shows that they are modified branches.

324 A TEXT-BOOK OF BOTANY.

A number of plants ascend into the air on other plants, or
other objects which serve as supports, either by attaching them-
selves to them or by twining around them, when they are dis-
tinguished as twiners and climbers. TWINERS ascend by a special
circumnutating movement of the stem, as in the morning glory,
Menispermum (Fig. 180), etc. CLIMBERS, however, ascend by
means of special structures, as the aerial roots of the ivy (root
climbers) ; or they may climb by means of leaves, as in Clematis
(leaf climbers) ; still others climb by means of tendrils, as in the
grape and Bryonia (tendril climbers) (Fig. 181) ; and again
plants may climb by means of hooked hairs or spines, as in Rubus,

FIG. 182. Rhizome of Podophyllum representing three years' growth: ba,the terminal
bud of last year; b2, the corresponding one of the present year; B.the terminal one of the
entire rhizome will develop in the spring of next year. L1 and L2 indicate the scars of aerial
leaves of the two preceding years' growth; bl and b2, latent buds. — After Holm.

Rosa, etc. The tendrils, which are thread-like modifications of the
stem, are in some cases provided with disk-like atachments for
holding the plant in position, as in the Virginia creeper. Twiners
and climbers are sometimes spoken of as LIANES (lianas), particu-
larly those of tropical regions, where they form a prominent
feature of the forest vegetation. The lianes usually have rope-
like, woody stems, the formation of leaves being either suppressed
or retarded, and they often run for long distances over the ground
and climb to the tops of the tallest trees. They are also frequently
characterized by an anomalous stem-structure, the tracheae being
very large.

Stems vary, furthermore, in size and form. While most stems
are more or less cylindrical or terete, other forms also occur, as

MORPHOLOGY OF HIGHER PLANTS.

323

the flattened stems in the Cactacese ; triangular in the Cyperaceae,
and quadrangular in the Labiatse and Scrophulariaceae.

Hypogeous Shoots. — While most stems attain a more or less
erect position, as in trees and shrubs, there are others which 'bend
over to one side, or lie prostrate on the ground, and in some cases

FIG. 183. Polygonatunt multiflorum, a plant growing in the Northern Hemispheres and
Japan and producing a rhizome resembling our Solomon's Seal (Polygonaium biftorum).
A, rhizome placed artificially higher in the soil than the normal depth; its continuation
shoot has grown downwards. B, rhizome placed deeper than the normal depth; its con-
tinuation shoot has grown upwards. The dotted lines at n indicate the amount of annual
growth in the rhizomes A and B. C, a seedling rhizome. At the right is the seed, which
encloses the haustorial end of the cotyledon; H, primary root; n, lateral roots arising within
the axis of the shoot; a, posterior side of cotylar sheath; v, anterior side of the same; b, c,
katophyls (or leaves on hypogeous shoots) on the axis of the seedling. — A and B, after
Rimbach; C, after Irmisch. (From Goebel's " Organography of Plants.")

produce roots from the nodes, as in Mentha spicata (Fig. 184).
These latter are known as STOLONS or runners.

Furthermore, the stems of a number of plants grow under-
ground, and these are known as RHIZOMES or ROOT-STOCKS (Figs.
182-190) ; from the upper portion of the nodes overground
branches arise which bear leaves (so that the work of assimilation

A TEXT-BOOK OF BOTANY.

may be carried on) as well as flowers, and from the lower surface,
roots (Fig. 182).

While most rhizomes are perceptibly thickened, and more or
less fleshy when fresh, as Sanguinaria, in other instances they are
of the ordinary thickness of the overground stem.

FIG. 184. Plant of spearmint (Mentha spicata) showing procumbent stems or leafy
runners from which roots are developed at the nodes, and one erect branch at the left from
which a new plant will be developed.

There are some rhizomes that are excessively thickened, as
in the common white potato (Fig. 185), and these are called
TUBERS. The so-called " eyes " are small buds covered with
small, scale-like leaves which develop into shoots. Tubers should

MORPHOLOGY OF HIGHER PLANTS.

327

not be confounded with tuberous roots, as those of the sweet
potato and jalap, for these latter have the morphological char-
acters of roots (compare Figs. 185 and 186).

Instead of the node, or internode, or both, becoming exces-
sively thickened, they may be reduced in size and crowded upon

FIG. 185. A potato plant grown from seed and showing the branches upon which the
potato tubers are formed, r, primary root; ct, cotyledons; c, hypocotyl; f, foliage leaves;
f', a primary branch the summit of which has developed foliage leaves; e'c, scales on upper
portion of primary branch; e'c', scales representing the eyes of the potato tubers formed
from the swollen branches; br, buds formed in the axils of the scales on the tubers; r', sec-
ondary roots formed on the stem branches. — After Duchartre.

each other, the leaves at the same time becoming thickened and
filled with nutriment. Such a modified stem and leaves, as in the
onion and tulip, is called a BULB (Fig. 188). Bulbs are sometimes
produced in the axils of the leaves of overground stems, as in some
lilies, and are then called bulbils or bulblets. They are also found
in Allium forming what are commonly known as " onion sets."

A TEXT-BOOK OF BOTANY.

FIG. 1 86. Several tubers formed by a 2-year non-flowering plant of A conitum Napellus,
gathered in September. The parent tuber on the right shows a portion of the overground
stem and a small bud (k); to the left has been developed an offspring tuber connected by
the branch (a) ; K, nearly full grown bud which will produce the foliage stem of the growing
plant the succeeding year. The long, filiform and branching roots are in the nature of true
root branches. — After Meyer.

Bulbs and tubers serve not only as storage-organs and carry the life
of the plant over from one season to another, but may form, as in

MORPHOLOGY OF HIGHER PLANTS. 329

bulblets, an important means of distributing the plants. The
thickened fleshy stems of Cactacese are also regarded as storage-
organs.

A CORM is intermediate between a true tuber and a bulb ;
it is more in the nature of a thickened internode, being surrounded
in some cases by thin, membranous scales, as in Crocus and
Colchicum.

The function of the vegetative shoot is to absorb nutrition
from the earth as well as from the air. The shoot may be AERIAL
or SUBTERRANEAN. Some plants possess only aerial shoots or
LIGHT-SHOOTS, as, for instance, trees, shrubs, and herbs that flower

FIG. 187. Rhizome of African ginger showing scars of overground branch (Ls) and
buds (k). The more or less parallel lines represent leaf-scars and scars of bud-scales, and
the small circles, root-scars. — After Meyer.

but once. Other plants possess both aerial and subterranean
shoots, and of these the subterranean shoot may exhibit some of
the peculiarities of roots, in that they do not develop chlorophyll
and produce secondary roots for the purpose of obtaining nutri-
tive substances from the soil. The SUBTERRANEAN SHOOTS are
generally destitute of true leaves and are furnished only with
membranous or sometimes thick, fleshy leaves which are bladeless,
pale, scale-like, or tubular.

Depending upon the duration of the shoot (or, better, the
stem), plants are divided into HERBS, SHRUBS, and TREES. In
herbs the aerial shoots are herbaceous, while in shrubs and trees
they become woody and persist throughout many years.

330

A TEXT-BOOK OF BOTANY.

Many of the herbs have subterranean shoots, but these are
generally absent from woody plants, excepting in Sambucus,
Ailanthus, Calycanthus, etc. The herbs may be further sub-
divided as annual, biennial, and perennial.

FIG. 188. Longitudinal section through a germinating bulb of Tulipa prcecox: h,
the brown enveloping membrane; k, the flattened stem which forms the base of the bulb
and bears the bulb-scales (sh); si, the elongated part of the stem which bears the foliage-
leaves (l'l')t and terminates in the flower; c, the ovary; p, perianth; a, anthers; 2, a lateral
bulb in the axil of the youngest bud-scale, which develops into the bud of next year's bulb;
w, the roots which arise from the fibrovascular bundles at the base of the bulb. — After
Sachs.

In ANNUAL herbs the individual possesses only aerial shoots
and the plant sets fruit the same year that the individual has de-
veloped from the seed. In BIENNIAL herbs the plant does not
produce flowers until the second season. The PERENNIAL herbs,

MORPHOLOGY OF HIGHER PLANTS. 331

on the other hand, develop flowers continuously for many (or at
least several) years and also produce subterranean shoots, such
as creeping rhizomes, tubers, bulbs, etc.

FIG. 189. Upper portion of rhizome of Gentiana lutea showing the structure of terminal
buds: A, terminal bud cut open to show the foliage leaves (b), which lie close to one another,
leaving only a narrow canal (s) in the middle. B, four-angled bud removed from A, showing
the foliage leaves having a strongly developed basal region (s) and relatively small lamina (sp) .
C, a small bud removed from the axis of the young leaves (B). D, upper portion of rhizome
of a flowering plant showing the stem base (S) and several buds (k). E, upper portion of
rhizome of a plant 6 years old showing scar (n) of the flowering branch and the strongly
developed side branches with terminal buds (k). The annulations are scars formed from
the bud scales which have dropped off. — After Meyer.

The roots of annuals, biennials, and perennials differ in a num-
ber of particulars. In the annuals, belonging to the monocoty-
ledons, the roots are fibrous, possessing numerous lateral branches,
whereas in the annuals belonging to the dicotyledons only the

332 A TEXT-BOOK OF BOTANY.

primary roots develop. The biennials are nearly all dicotyledons
and have a persistent primary root which, while usually slender,
may become fleshy, as in Beta. In the perennials, on the other
hand, we find a number of different types of roots, varying from
the slender aerial roots of epiphytes to the smaller tuberous,
fleshy roots of many terrestrial plants, and the peculiar roots of
parasites.

ALTERATIONS IN THE FORM OF PLANTS. — The shoot, in its

FIG. 190. Specimens of "orris root" of commerce consisting of peeled pieces of the
rhizomes of Iris florentina. The rhizomes are mostly dichotomous, the branches becoming
obconical and of characteristic shape. The large circular areas terminating the rhizomes
are scars of stem bases, while the small black dots on the surface are scars from attachment
of roots.

course of development, is subject to a great many hostile external
conditions, and there results more or less mutilation and alteration
in the form of the plant. One of the most destructive influences
to plants is that of strong winds when they attain the the velocity
of gales. They stunt the growth of woody plants and cause the
branches to assume a horizontal position (Fig. 191). This un-
usual growth is further accentuated if at times during the winter
they are covered with snow and sleet. If they grow in close

MORPHOLOGY OF HIGHER PLANTS.

333

334 A TEXT-BOOK OF BOTANY.

proximity their limbs will lash .each other, causing a flattening
of the top which is very characteristic in the groves of trees on
the sea coast. In this way it is possible for the whip-like branches
of the birch to mutilate even the tops of the fir tree, changing
their spire-like summits to deliquescent crowns. Injuries causing
an alteration in the form of plants are also caused by ruminating
animals and leaf-devouring insects.

GALLS. — These are abnormal developments on the young twigs,
leaves, and flowers, being caused by the punctures and presence
of the deposited ova of quite a variety of insects. Galls vary in
size, form, and general appearance. They are only capable of
being produced either in meristematic cells or in tissues that are
capable of exercising this function. They are never formed on
mature stems, leaves, or flowers. The older parts may be eaten
and destroyed by insects, but they are not capable of being meta-
morphosed. In these growing tissues the mother insect lays her
eggs, which upon further growth, either through the secretion of
particular substances or otherwise, determine the direction of
growth of the cells and the final product which shall be formed.

As has already been stated, galls show considerable variation,
and, as there are many hundreds of distinct galls, various attempts
have been made to classify them. Kuster has proposed an ana-
tomical classification as follows: i. Galls in which there may be
an enlargement of cells, but no cell multiplication ; 2. Soft galls,
composed of numerous cells, the resulting product being more or
less fleshy ; 3. Hard galls, in which there is an active cell division,
and sclerotic modification of the external layer so as to prevent
the drying up of the gall in summer and to guard against attack
by birds and other animals. Modry ( Beitrage zur Gallenbiologie) ,
on the basis of Kuster's classification, has given a very compre-
hensive review of the various structural (both external and in-
ternal) characters of the various groups of zoo-cecidia.

In a classification of galls Thomas has suggested as a class
name for these structures the word CECIDIEN (meaning nut-gall).
The cecidien or galls are divided into two main groups, as fol-
lows : I. PHYTO-CECIDIEN or fungus galls, including the parasitic
fungi which cause a metamorphosis in the shoots of larger shrubs
and trees forming the structures commonly known as " Witches'

MORPHOLOGY OF HIGHER PLANTS. 335

brooms." Galls exhibiting strange forms are also produced by
the Gymnosporangia on the stems of the common juniper, the
leaves of the mountain ash, etc. In this group would also be
included the CROWN-GALLS occurring on a large number of plants,
as grapes, peach, juniper, and field crops. At one time it was
thought that these galls were due to frosts or mechanical injuries.
The extended researches of Smith (Bulletin No. 213, Bureau of
Plant Industry, U. S. Department of Agriculture) have shown
that crown-galls are in the nature of bacterial diseases. He
showed that crown-galls not only resembled malignant animal
tumors, especially sarcoma, but demonstrated that this resemblance
was more than superficial. II. ZOO-CECIDIEN, or those galls which
are formed within the body of the plant and due to attacks by
insects. This group includes by far the larger number of galls,
and is further subdivided according to the various animal-groups
causing them.

Galls differ in structure, but the general nature of the anat-
omy may be seen in a study of the common " ink ball " or " ink
gall," formed on Quercus coccinea by Cynips aciculata. These
galls are produced during the summer months on the young
branches and sometimes on the acorns. When mature they fall
from the trees and are nearly globular in shape, varying from 20
to 30 mm. in diameter. They are solid throughout and of the
consistency of the pulp of a green apple. Externally they are
smooth, and are colored a mottled green, yellow, or brownish-
red. At this stage they are made up of three distinct zones:
( i ) A central area, made up of nearly isodiametric starch-bear-
ing, parenchymatous cells. (2) The middle zone is composed
of radially elongated parenchymatous cells, possessing thick,
porous cellulose walls containing a lining of protoplasm and a few
starch grains. With the development of the egg of the insect
there also appear in the cells of this middle zone numerous starch
grains closely resembling those found in the central zone. (3)
An external layer made up of irregular parenchymatous cells,
somewhat collenchymatic in character, with a lining of protoplasm
as in the cells of the middle zone.

In some studies on the origin of tannin in galls Kraemer (Bot.
Gas., 1900, p. 275) showed that in the " ink gall " there are three

336

A TEXT-BOOK OF BOTANY.

stages in their development, corresponding to the life periods of
the insects and dianges in the constituents of the cells: (i)
When the galls are first formed and the larva is beginning to de-
velop, the cells of the outer zone, as well as those of the central

FIG. 192. Transverse section of one of the collateral mestome strands of the stem of
Viola tricolor arvenis: o, portion of cells of pericycle; e, endodermis; 1, leptome or sieve
cells, in among which are some collenchymatous cells (c) ; m, cambium; t, spiral tracheae or
vessels; g, strongly lignified tracheae; rp, medullary ray cells, the walls of which are com-
posed of cellulose; rs. medullary ray cells the walls of which are strongly lignified; s,
strongly lignified cells separating the mestome strands ; c, collenchyma; p, pith.

zone, contain numerous small starch grains. (2) When the in-
sect reaches the chrysalis stage the starch in the cells near the
middle of the galls is replaced in part by gallic acid, while the
cells at the center and near the periphery contain masses of tannic

MORPHOLOGY OF HIGHER PLANTS. 337

W

FIG. 193. Collateral fibrovascular bundle in Menispermum: C, cortex; B, bast
fibers; St, stone cells connecting groups of bast fibers; S, sieve; M, cambium; T, tracheae;
W, wood fibers; R, medullary rays; P, pith.

22

338 A TEXT-BOOK OF BOTANY.

acid. (3) When the winged insect is developed nearly all of
the cells contain amorphous masses of tannic acid with some
adhering crystals of gallic acid. After the insect has emerged
from the gall the constituents again undergo change, depending
largely on the presence of moisture, when the tannic acid is changed
into more or less insoluble products and the galls become more
porous.

THE INNER STRUCTURE OF THE STEM.

If we make a transverse section of a young herbaceous stem,
we observe a differentiation of the tissues, which in several re-
spects agrees with that of the root previously described. In the
primary structure of the stem the following tissues are to be
noticed : The outermost layer is the epidermis with a more or
less distinct cuticle ; the second is the cortical parenchyma, fre-
quently having strands of collenchyma near the epidermis. The
cortex often contains secretory cells or receptacles, and not infre-
quently the innermost layer is differentiated as an endodermis.
The latter surrounds the so-called pericycle, a sheath consisting
of more or less distinct stereomatic strands, either forming a
closed sheath or merely representing isolated arches outside the
leptome of the stele. Inside the pericycle we observe the mestome
strands constituting mostly one circular band (in cross section)
in the Dicotyledons and Gymnosperms, or several more or less
concentric bands in the Monocotyledons. The mestome strands
or fibrovascular bundles may be collateral (Figs. 192-194), bi-
collateral or concentric, the last of which being found only in the
Monocotyledons (Fig. 195) and Ferns (Fig. 56).

In the DICOTYLEDONS the collateral fibrovascular bundles occur
most frequently and consist of three distinct portions, viz., phloem,
xylem, and cambium. The phloem consists of sieve tubes, com-
panion cells (or accompanying cells), and cambiform. The last
two are thin-walled parenchymatous cells, those of the cambiform
being considerably elongated. In addition there may be included
in the phloem the stereomatic tissues or bast fibers, which are not
infrequently well developed. The xylem includes tracheae or
vessels, tracheids, wood parenchyma, and libriform or wood fibers.

To the student some confusion may arise as to the apparent
indiscriminate use of the terms, leptome and hadrome, the former

MORPHOLOGY OF HIGHER PLANTS

FIG. 194. Dicotyledonous stem structure. Transverse section through menisperrnum
rhizome: E, epidermis; K, sub-epidermal cork; C, cortex; B, bast fibers; S, sieve; ST,
Stone cells; CA, cambium; T, vessels; W, wood fibers; M, medullary ray cells; P, pith.

340

A TEXT-BOOK OF BOTANY.

FIG. 195. Monocotyledonous stem structure. Transverse section of convallaria
rhizome: E, epidermis; H, hypodermis composed of collenchyma; C, cortex; EN, endo-
dermis; S, perihadromatic sieve; T, tracheae or vessels; P, parenchyma. The bundles are
of the collateral and concentric types.

MORPHOLOGY OF HIGHER PLANTS.

341

being used as being apparently synonymous with phloem and the
latter being equivalent to xylem. As a matter of fact, these terms
are not equivalent, the phloem proper including bast fibers in
addition to leptome ; and the xylem being composed of wood
fibers in addition to hadrome; nor is the fibrovascular bundle
synonymous with mestome strand, as the former includes not only
the conducting tissues but the mechanical tissues as comprised in
the xylem and phloem ; while the mestome strand includes only
the conducting cells comprised in the leptome and in the hadrome,
there being no sclerenchymatous fibers present. The following
table will doubtless make clear to the student the relationship
of these tissues to each other:

Mestome or

vascular

bundle

Leptome or
Sieve portion

Hadrome or
Tracheal portion

Stereome or
Bast fibers

f Sieve tubes

< Accompanying cells \
(.Cambiform J

Cambium

[Tracheae

< Tracheids

I Wood parenchyma

Libriform or
Wood fibers

Phloem

Fibro-
vascular
bundle

Xylem

When the collateral mestome strand increases in thickness, the
increase is due to the activity of the cambium, here called the
INTRAFASCICULAR CAMBIUM, which then develops phloem or lep-
tome outwardly and xylem or hadrome inwardly. Between the
primary mestome strands there is frequently a procambium,
which connects these strands with each other, and which gener-
ally gives rise to secondary mestome strands, or the connection
may be effected by means of the intrafascicular cambium, which
often extends itself from one strand to another and develops lep-
tome and hadrome, as in the primary strands ; such cambium is
distinguished as INTERFASCICULAR CAMBIUM and is commonly
referred to as the CAMBIUM RING.

The BICOLLATERAL mestome strands or fibrovascular bundles,
characteristic of some Dicotyledons (Labiatse, Solanacese, Cucurbi-
tacese, etc.), differ from the COLLATERAL type by having a leptome

342

A TEXT-BOOK OF BOTANY.

strand developed on the inner face of the hadrome; thus each
mestome strand carries two strands of leptome (Fig. 197, C). In
the CONCENTRIC mestome strands the leptome may encircle the
hadrome, as in the Ferns (Fig. 56), or the hadrome may partly

Kt

Hr

St

Sr

Mt

Mi

FIG. 196. The outer bark and part of trie inner bark of Rhamnus Purshianus in trans-
verse, radial-longitudinal, and tangential-longitudinal sections. Me, transverse section of
inner bark; Mt, tangential-longitudinal section of inner bark; Mr, radial-longitudinal section
of inner bark; Sc, transverse section of stone cell area; St, tangential-longitudinal section
of stone cell area; Sr, radial-longitudinal section of stone cell area; He, transverse section
of outer layers of cortex; Hr, radial-longitudinal section of outer layers of cortex. Kc, Kt,
Kr, transverse, tangential-longitudinal, and radial-longitudinal sections of cork; b, bast
fibers; f, crystal fibers; p, parenchyma; e, sieve; sk, stone cells; m, medullary ray cells;
c, collenchyma.

(as in the rhizomes of many Monocotyledons) surround the lep-
tome (Fig. 195). While thus the collateral type of strand or
bundle occurs in both Monocotyledons (Fig. 195) and Dicotyle-
dons (Figs. 192, 193), etc., the presence of a cambium is found
only in the Dicotyledons and occurs extremely seldom in the Mono-

MORPHOLOGY OF HIGHER PLANTS.

343

cotyledons. The central portion of the stele is frequently differ-
entiated into a PITH of parenchymatic structure, the cells of which
often contain large quantities of starch. In addition in the pith,
we often find the same types of secretory cells or receptacles as
occur in the cortex (as in Apocynum). The pith may constitute
a homogeneous tissue or be broken, as in Phytolacca, Carya,
Halesia, etc., where a longitudinal section shows the pith divided
into a row of broad cavities formed by a separation of the cells
as a result of the rapid longitudinal growth of the stem

Finally it may be mentioned that cork is of frequent occur-
rence, especially upon stems that persist more than one year.
The cork may arise in the epidermis itself, or it may develop in
the hypodermal strata of the cortex, or in still other cases we find
its development much deeper, even within the pericycle.

FIG. 197. Schematic representation of different types of mestome strands or fibro-
vascular bundles: s, sieve; t, tracheae or vessels; e, position of the earliest tracheae formed;
a, radial bundle or mestome strand; b, collateral bundle; c, bicollateral bundle; d and e,
concentric bundles. — After Meyer.

In regard to the increase in thickness, the stem develops much
like the root, as in the throwing off the peripheral tissues extend-
ing from the epidermis to the endodermis, or of the epidermis
and adjoining cortex, the displaced tissues are replaced by strata of
cork and secondary cortex. The mestome strands in the stem,
however, grow in a more regular manner than is the case with
those of the root, as is seen in the very distinct and frequently
very regular layering of the tissues of woody stems, forming the
so-called " Annual Rings," where each ring represents the growth
that occurs during a single year. The development of these
annual rings depends especially upon the fact that the growth
of the perennial stem does not take place continuously, but is in-
terrupted during certain periods of the season, for instance dur-
ing the winter or during the dry seasons of tropical climates.
And since the tissues which are formed at tHe beginning of each

344

A TEXT-BOOK OF BOTANY.

season's growth are distinct from those already formed during
the previous season in both color and structure of the wood (espe-
cially in the thickness of cell-walls and the width of the tracheae
or vessels), we perceive in this manner distinct zones of wood,
or the " annual rings " as they are called, the larger vessels with
thin walls being produced in the spring and early summer.

Various abnormal stem-structures are known which are due

FIG. 198. Transverse section of wood of Rhamnus Frangula showing that the annular
rings seen in woody portion of plants is due to a difference in the nature and structure of the
cells formed in the spring and in the fall. In the spring numerous large tracheae or vessels
(v) are formed, whereas in the fall very few vessels and mostly wood fibers are developed,
the cells of these being smaller as they approach the end of the year's growth.— After Rossmann.

to certain peculiarities in the growth in thickness of stems. These
are especially noticeable in lianes. In some of the Monocotyledons,
as in Dracaena, Yucca, Agave and Aloe, we find a secondary in-
crease in growth of the stems.

In summarizing the root and stem structures of Monocotyle-
dons and Dicotyledons the following general facts should be
borne in mind. Monocotyledonous stems resemble Monocotyle-
donous roots except that the fibrovascular bundle or mestome

MORPHOLOGY OF HIGHER PLANTS.

345

strand of the former is concentric, whereas in the latter it is
radial. The primary structure of Dicotyledonous roots is much
the same as in Monocotyledonous roots. The primary structures
of Dicotyledonous stems resemble the primary structure in Dicoty-
ledonous roots except that the fibrovascular bundles of the former
are of the collateral type. The secondary structures of both roots
and stems of Dicotyledons are oractically alike. The characteristics

FIG. 199. Section of a four-year-old stem of a pine cut in winter; q, view in trans--
verse section; 1, radial-longitudinal section; t, tangential-longitudinal section; f, spring
wood; s, fall wood; m, pith; i, 2, 3, 4, successive years' rings of growth in which is shown
the dividing line; ms, medullary rays in transverse section; ms1, ms11, medullary rays
in radial-longitudinal section; ms111, medullary rays in tangential-longitudinal section:
c, cambium; b, bast; h, resin-canals; br, bork. — After Strasburger.

distinguishing the primary and secondary structures of Dicotyle-
donous stems may be summarized as follows :

PRIMARY STRUCTURES. — Epidermis, hypodermis, primary cor-
tex, endodermis, pericambium or pericycle, stele consisting of
collateral fibrovascular bundles and pith.

SECONDARY STRUCTURES. — Periderm derived from phellogen;
secondary cortex, consisting of parenchyma and occasionally
stone cells or secretory cells or vessels; phloem consisting of
sieve, accompanying cells and sometimes bast fibers ; cambium in

346

A TEXT-BOOK OF BOTANY.

A B

FIG. 200. Coarse structure of a number of woods as seen with a Coddington lens:
A, English walnut (Juglans regia) showing the tracheae evenly distributed in the form of
pores, which can be seen in the wood with the naked eye; the medullary rays are rather
faint and arranged in closely radiating, parallel rows; in the fall wood are numerous fine
transverse lines parallel with the annular markings. B, shell-bark hickory (Carya ovata)
showing a row of large tracheae (g) in the summer wood and somewhat smaller tracheae (g')
scattered throughout the subsequent growth; medullary rays numerous, as are also the
somewhat undulating transverse lines (F). C, white or canoe birch (Betula pendula) showing
distinct annular rings and numerous medullary rays between which are scattered the small
tracheae indicated by black dots. D, chestnut (Caslanea dentata) showing large tracheae
arranged in circular groups, those of the successive layers being smaller and arranged some-
what obliquely, forming triangular groups; medullary rays very faint; E, Elm (Ulmus
campestris) showing tracheae arranged in circles in the summer wood and in the later growth
a number of broad more or less undulating plates composed of very small tracheae; medullary
rays quite distinct; F, Cherry (Prunus domestica), tracheae quite distinct in the summer
wood, forming several circular rows; medullary rays broad and distinct. — B, after Wiesner;
the remainder after R. Hartig.

MORPHOLOGY OF HIGHER PLANTS. 347

the form of a ring known as interfascicular cambium ; xylem com
posed of tracheae, wood parenchyma, usually wood fibers and
sometimes tracheids; medullary rays separating the collateral
bundles; pith composed of parenchyma and sometimes having
stone cells and secretory cells similar to those found in the cortex.
In stems having bicollateral bundles, strands of phloem also* occur
on the inner surface of the xylem rays.

IMPORTANCE OF THE STUDY OF THE STRUCTURE OF WOOD. —
The structure of stems in woody plants is very characteristic, not
only in different families but in genera and at times in species.
In the Pinaceae, for instance, the wood is entirely made up of
tracheids, the tracheae being wanting. In most of the Dicotyledons
tracheae are present, being absent only in certain water plants as
Nymphaeaceae and in Drimys, a genus of the Magnoliaceae. In
the Cactaceae the secondary wood is provided with annular and
spiral tracheids. In practical work, whether it be in the study of
plants for taxonomic purposes or for their industrial uses, the
following are some of the observations that should be made:
I. Structure of the walls and nature of the perforations or mark-
ings in the tracheae or vessels. 2. The presence or absence and
relative distribution of libriform or wood fibers (often referred
to as wood prosenchyma). 3. The structure of the medullary
rays not only as regards thickening of the walls and contents of
the cells, but the number of the cells both as to width and height
entering into the individual groups of rays. 4. Wood paren-
chyma is variously distributed, the cells aggregated about the
vessels being distinguished from those that form tangential bands
separating the circles of vessels. The distribution of the crystals
is also of importance, as they may occur in isolated cells or in
superimposed cells adjoining the wood fibers and form the so-
called crystal fibers.

In the study of different commercial woods it is customary
in practice to study the coarser features such as can be recog-
nized by the help of an ordinary hand lens. In this superficial
study many distinctive characteristics can be readily determined, as
the nature of the annual rings, the size of the lumina of the ves-
sels, as well as their abundance and arrangement, etc. (Fig. 200).

348

A TEXT-BOOK OF BOTANY.

III. THE OUTER MORPHOLOGY OF THE LEAF.
Leaves are lateral formations upon the stem and their growth
is definite. They never occur on other portions of the plant than
stems, from the surface of which they are developed. Leaves
appear in acropetal succession, so that the youngest leaves occur
nearest the apex of the stem. Terminal leaves are extremely
rare, but arise in some instances from the flowers o>f certain
Euphorbiaceae.

FIG. 20 1. A, leaf of violet (Viola tricolor) showing broad lamina, long petiole, and one
of the palmately-lobed stipules at the base of the petiole. B, C, stages In the development
of the leaf. The lobes of the stipules (s) develop before the lamina (1).

A Simple Leaf consists of a LAMINA or blade, which is usually
membranous and of a green color, and a PETIOLE or stalk, which,
however, may be wanting when the leaf is said to be sessile.
Leaves may also possess a pair of leaf-like structures at the base,
known as STIPULES (Figs. 201, 204). The principal function of
the latter appears to be that of protecting the buds, as in the
tulip poplar (Liriodendron) (Fig. 204), although they may be-
come leaf-like and assist in the functions of the lamina, as in
Viola tricolor (Fig. 201).

MORPHOLOGY OF HIGHER PLANTS. 349

Light Relation of Leaves. — While the lamina of the leaf
appears to assume a more or less horizontal position, it usually
inclines at such an angle as to receive the greatest amount of dif-
fused daylight. Wiesner has shown, for instance, that when
plants are so situated that they receive direct sunlight only for a
time in the morning, and diffused daylight during the rest of the
day, the position of the upper surface is at right angles to the
incident rays of daylight, and not to that of the rays of the
morning sun. This phenomenon may be studied in the house
geranium and other window plants. In endeavoring to explain this
behavior of the leaves, Frank assumes it to be due to a kind of
heliotropic irritability peculiar to dorsiventral organs, and terms

it TRANSVERSE HELIOTROPISM.

The stem, as well as the petiole or stalk of the leaf, is also
influenced by the light, and is said to manifest positive helio-
tropism. Those parts of plants that turn away from the light, as
the aerial roots of the ivy, are said to possess negative helio-
tropism.

Depending upon their relation • to external agents, several
forms of leaves are distinguished. In those which assume a more
or less horizontal position the two surfaces of the lamina are
quite different, and the leaves are said to be DORSIVENTRAL, or
bifacial. Usually there is a more compact arrangement or stronger
development of chlorophyll tissue on the upper or ventral surface,
while on the lower or dorsal surface the veins stand out more
prominently, and there is a greater number of stomata.

In contrast with this type of leaf may be mentioned those
which grow edgewise and in which both surfaces of the leaf are
more or less alike, as in the Eucalypts and Acacias of Australia.
In Iris and Calamus, the leaf-like organ is actually not the blade,
but merely a part of the dorsal face, which, in the bud, has already
pushed out so as to exceed the apex. Such leaves are called
SWORD-SHAPED and are frequently referred to as EQUITANT. The
leaves of certain species of Juncus, Carex and some of the grasses
are commonly spoken of as CYLINDRIC. Such leaves are, how-
ever, only apparently cylindrical, since the ventral surface is
often distinct, though much narrower than the dorsal. They
are also frequently hollow.

350 A TEXT-BOOK OF BOTANY.

Functions of the Leaf. — When we speak of the leaves of
the plant we usually have in mind the foliage leaves or green
chlorophyll leaves.

Under the influence of sunlight the chloroplasts are able to
rearrange the elements in carbon dioxide and water, which are;
looked upon as inorganic substances, into starch or related com-
pounds which are of an organic nature. This process is known
as carbon dioxide assimilation, or PHOTOSYNTHESIS, which latter
term means the building up of a compound under the influence of
light. In this process, which is sometimes expressed by the fol-
lowing formula, oxygen is given off :

6C02 + 5H20 =. C6H1005 + 602

Carbon dioxide Water Starch Oxygen

The importance of this function can be best appreciated by
bearing in mind that all of the organic products built up by the
plant are derived almost entirely from the carbon dioxide of the
air which is taken in through the leaves. (Consult also pages

I57-I59-)

Transpiration and respiration are also functions of the leaf.
TRANSPIRATION is the giving off of water (through water-pores),
or watery vapor (through the stomata), which has been absorbed
by the root-hairs and transported through the tissues of the root,
stem and leaf ; the process of breathing, or RESPIRATION, consists
in the taking in of oxygen and giving off of carbon dioxide, the
exchange being just the reverse of what it is in photosynthesis.
These several functions are, however, not confined to the leaf
alone, but are carried on by all the green parts of the plant.

PHYSIOLOGICAL EXPERIMENTS. — The leaf is undoubtedly the
most active part of the plant from the physiological point of view.
Some of its activities can be demonstrated by comparatively sim-
ple means.

For instance, it can readily be shown, that leaves or rather
chloroplastids form starch when exposed to sunlight but that no
starch is formed when the light is not admitted, by a simple con-
trivance called a leaf shield. This is a device by which a thin
piece of glass can be clamped against the leaf. Over a portion of
this glass a piece of tinfoil may be pasted, thereby shutting off
the light from the underlying area. The procedure consists as

MORPHOLOGY OF HIGHER PLANTS. 351

follows : On the day previous to the demonstration of the experi-
ment the leaf shield is clamped on the leaf. On the following day
the leaf is allowed to stand well exposed to the sunlight for
several hours. The leaf is then removed from the plant, separated
from the leaf shield, and after the chlorophyll is extracted by
boiling in alcohol it is placed in weak iodine solution, whereby the
entire part of the leaf exposed to the light is darkened in color,
while the area protected by the tinfoil remains unchanged.

The phenomenon of photosynthesis whereby the leaf uses
carbon dioxide and gives off oxygen can be demonstrated by means
of a photosynthometer. Ganong gives a detailed description of
its construction and use. The underlying principle is that a
known volume of leaf material is supplied with a known volume
of carbon dioxide. After submitting the leaf to the sunlight a
test is made of. the proportion o-f carbon dioxide and oxygen in the
graduated tube, from which the activity of the leaf may be
accurately deduced.

The process of transpiration in leaves can also be readily
shown. The mere fact of transpiration can be shown by inserting
the leaves of a plant into a bell-jar which has at its base a sheet
of rubber or other suitable material stretched over the opening
with just sufficient aperture to admit the stem. The root being
outside of the bell- jar can be kept moist and as transpiration
takes place the moisture condenses on the inside of the glass.

By means of an arm balance and devices for measuring the
water supplied the plant, together with some covering to prevent
evaporation from the surface of the soil, rather accurate deter-
minations can be made of the quantities of water given off by the
plant and calculations made for each square unit of leaf surface.

The potometer is another ingenious simple contrivance which
measures most accurately the amount of water transpired. It
consists of a horizontally placed graduated tube which ends in a
short vertical portion into which a stem bearing leaves can be
tightly inserted after the instrument is filled with water. By
means of a reservoir at the side and a stop-cock more water can
be admitted as needed. Accurate readings over short periods of
time are facilitated by admitting a small bubble of air as an index
and observing the time of its passage along the graduated tube.

(Consult Ganong: Plant Physiology.)

352

A TEXT-BOOK OF BOTANY.

Leaf Venation. — The foliage leaves of higher plants are
traversed by vascular bundles, which enter the blade through the
petiole and diverge at the base, or, as in the case of Dicotyledons,
branch in various ways ; and it will be seen that the form of the
leaves corresponds to the distribution of the bundles. These
bundles are known as veins or nerves, and they have two func-
tions, namely, (i) that of a mechanical support, and (2) that of
carrying nutritive materials to and from the leaves.

The mode of venation in Monocotyledons and Dicotyledons
differs somewhat, but it will be found that in a number of instances

FIG. 202. Leaf venation: A, parallel-veined leaf of Solomon's seal (Smilacina race-
mosa); B, pinnately-reticulate leaf of chestnut; C, palmately-veined leaf of Menispermum
canadense.

the venation of leaves of plants belonging to one of these great
groups will resemble that of the leaves of certain plants in the
other group. However, there are certain general types belonging
to each group (Fig. 202).

VENATION IN MONOCOTYLEDONS. — An examination of the
leaf of lily-of- the- valley shows that the primary veins run more
or less parallel to the apex with short though distinct anastomoses.
Such a leaf is said to be PARALLEL-VEINED or NERVED. It will
moreover be noticed that. the distribution of the veins in this
manner produces a lamina with an even, or entire margin, and

MORPHOLOGY OF HIGHER PLANTS. 353

such a system of venation is known as a closed system of venation
(Fig. 202, A). The leaves of Veratrum and Zea Mays furnish
other examples of parallel-nerved leaves.

In palms the venation is somewhat different. The veins,
instead of converging toward the apex as they do in the more or
less lanceolate leaf of lily-of -the- valley, radiate from the base
to the margin of the more or less round leaf, and a leaf of this
type is said to be PALMI-NERVED.

There is still a third type of venation in Monocotyledons. In
this instance one principal vein runs from the base to the apex
of the leaf, and from this branches run parallel to the margin.
The banana furnishes an example of this type, and is said to be

PINNI-NERVED.

VENATION IN DICOTYLEDONS. — Here the veins are character-
ized by their habit of repeatedly branching and anastomosing,
whatever the general type of venation may be, and thus form a
net-work or reticulum, hence the leaves are said to be RETICULATE
or NETTED-VEINED. The principal types are as follows : A chest-
nut or chinquapin leaf (Fig. 202) furnishes a good illustration
of a pinnately-reticulate leaf. The principal vein which runs from
the base to the apex is called the MIDRIB, while the secondary
veins which arise from it and run more or less parallel to the
margin are sometimes spoken of as ribs and may be likened to the
plumes on the shaft of a feather.

In other cases several large veins arise at the base and diverge
toward the margin, giving rise to PALMATELY-VEINED leaves, as
in the leaf of maple. There are still other types, as in cinnamon,
which is said to be rib-netted, etc.

Surface of Leaves. — In addition to the markings of leaves
due to veining there are certain other characters which serve
to distinguish them. Hairs are of frequent occurrence on leaves,
being generally most abundant on the dorsal surface, especially the
veins, and various terms having reference to the kinds of hairs
have been applied to leaves.

Plant Hairs. — When the surface of the plant (either of stems

or leaves) is covered with short, fine hairs, which are not very

dense and not matted, the surface is described as PUBESCENT;

when the hairs are relatively long but scattered the surface is said

23

354 A TEXT-BOOK OF BOTANY.

to be VILLOUS; or when the hairs cover each other in one direction
it is described as SERICEOUS or silky. When the hairs are stiff
though slender we speak of a HIRSUTE covering; when the hairs
are vernate, thickish and stiff, as in Borago, the surface is spoken
of as being HISPID. If the hairs are bristle-like the surface is
described as STRIGOSE; or if they are terminated by a globular,
glandular head (Figs. 100, 124), as GLANDULAR. Again, when
the hairs are matted the surface is described as LANATE; when
they are long it is said to be WOOLLY; or when they are short
and soft as in Mullein it is said to be TOMENTOSE.

When the hairs are hard and prickle-like the surface is
described as HISPID or STRIGOSE ; when they are modified to spines
it is said to be SPINOSE ; and when they are hooked it is described

as ECHINATE.

In still other cases the epidermal cells, particularly of leaves,
are uneven, forming depressions and protuberances which if
slight give the surface the appearance described as RUGOSE ; or if
wart-like, give the appearance known as VERRUCOSE. Further-
more, the veins of leaves may be quite prominent, particularly
in the lower surface, and if they are much reticulated in addition,
the surface is described as RETICULATE.

Texture of Leaves. — Leaves also vary in texture. A thin
pliable leaf is called membranous ; one which is thick and leathery,
coriaceous ; and one which is thick and fleshy, succulent, as that
of the century plant and Aloe (Fig. 130).

Forms of Leaves. — The leaves of plants exhibit an almost
innumerable variety of forms ; even on the same plant there are not
infrequently several forms, as in Viola tricolor and sassafras
(Fig. 203) ; even the two margins of the same leaf may vary, as in
Hamamelis and Begonia, when it is known as an inequilateral
or asymmetric leaf. It frequently happens that- the lower leaves
on a shoot are lobed while the upper ones are entire, or some of
the leaves may be sessile and other petiolate. Many of the terms
used in ordinary language in describing the forms of objects are
applied here also, as linear, lanceolate, oblong, elliptical, spatulate,
wedge-shaped, etc.

APEX OF LEAF. — A number of descriptive terms are employed
in describing the apex of the lamina, as ACUTE, when the form is

MORPHOLOGY OF HIGHER PLANTS.

355

that of an acute angle; OBTUSE, when the angle is blunt; ACUMI-
NATE, when the angle is prolonged ; TRUNCATE, when the end of

FIG. 203. Variation in the form of leaves on the same plant: A, B, C, Leaves or
sassafras; ,D, young castor oil plant showing cotyledons (t) and variously lobed older
leaves. 1, lamina; p, petiole.

the leaf appears to be cut off ; RETUSE, when it is slightly notched
at the apex ; OBCORDATE, when the notch is pronounced ; EMAR-
GINATE, when the degree of notching is between retuse and

356 A TEXT-BOOK OF BOTANY.

obcordate. Sometimes the apex appears like the continuation of
the midrib, when it is termed CUSPIDATE or mucronate.

BASE OF LEAF. — Some of the terms used in describing the gen-
eral outline, as well as the apex of the leaf, are also applied to the
base, as obtuse, truncate, cordate, reniform, etc. Other terms,
however, especially apply to the base, as CUNEATE or wedge-
shaped; CONNATE-PERFOLIATE, when opposite leaves are con-
nected at the base and surround the stem ; PERFOLIATE, when the
leaf simply clasps the stem. In Monocotyledons the base of the
leaf is frequently developed as a closed or open sheath, some-
times provided with a membranous protuberance between the
sheath and the blade, as in the LIGULE of grasses and sedges.

MARGIN OF LEAF. — The leaves of many woody dicotyledonous
plants of temperate regions possess an even margin. The others,
according to the degree and character of the incisions or inden-
tations, are described as SERRATE, when the apex of the divisions
or teeth is sharp and directed forward like the teeth of a saw ;
DENTATE, when the divisions project outward; CRENATE, when
the teeth are more or less rounded ; REPAND, when the margin is
somewhat wavy ; SINUATE, when the wavy character is pro-
nounced ; LOBED, when the incisions extend not more than half-
way into the lamina, and the sinus (or hollow) and the lobes are
more or less rounded ; CLEFT, when the incisions are still deeper
and the sinuses and lobes are somewhat acute; and DIVIDED (Fig.
205 ) , when the incisions extend almost to the midrib.

Compound Leaves. — The divisions of a parted leaf may
assume the form of a simple leaf, when the divisions are known
as LEAFLETS and the whole as a compound leaf. The distinction
between a simple leaf and a leaflet is, that the former has a bud in
the axil. The difference between the divisions of a simple leaf
and those of a compound leaf is this, — in the former they never
become detached from the petiole or midrib, whereas in the com-
pound leaf they are articulated and drop off individually. Com-
pound leaves may be divided into PiNNATELY-compound (Fig. 204)
or pALMATELY-compound (Fig. 210, E), this distinction depend-
ing upon whether the leaflets are arranged pinnately or palmately.
A number of forms of pinnately-compound leaves are recognized.
When the leaflets are all lateral (Fig. 207) the leaf is said to be

MORPHOLOGY OF HIGHER PLANTS.

357

PARI-PINNATE; when there is an odd or terminal leaflet as in
the locust (Fig. 204) the leaf is IMPARI-PINNATE; when the midrib

FIG. 204. Leaves having different forms of stipules (s) : A, bud-scale stipules of Lirio-
dendron Tulipifera; B, thorny stipules and odd-pinnate compound leaf of the locust tree
(Robinia Pseud-acacia); C, adnate stipules of rose; D, filiform stipules of the pear; E, fringed
clasping stipules (ocrea) characteristic of all of the Polygonums; F, adnate stipules of clover.

is prolonged into a tendril as in the garden-pea (Pisum) the
leaf is said to be CIRRHIFEROUS-PINNATE.

Movements of Leaves. — The leaves as well as other organs
of plants exhibit a variety of movements or curvatures in response

358

A TEXT-BOOK OF BOTANY.

to stimuli of different kinds, and are said to possess the property
of irritability. Movements of organs are of two general classes :
(i) Those due to stimuli which originate in the plant and (2)
those due to the influence of external factors. To the former class

FlG. 205. Limnophila heterophylla, a marsh-plant belonging to the Scrophulariacese
and growing in tropical Asia. The submerged or water leaves, below, are much divided and
arranged in apparent whorls; while the leaves at the end of the shoot above water are entire
and arranged in decussate dimerous whorls. In between occur transition forms, which are
divided and variously lobed and arranged in decussate whorls. — After Goebel.

belong all those movements which occur during the course of
development from the young to the mature stage. These are
known as growth movements or NUTATION. They are especially
noticeable in tips of growing branches, which instead of growing

MORPHOLOGY OF HIGHER PLANTS. 359

FIG. 206. i, Leaf, fruits and flowers of Anemone Pulsatilla. 2, Leaf, flower and fruit
of Anemone pratensis. The leaves are pinnately divided, the divisions being further incised
or dissected.

360

A TEXT-BOOK OF BOTANY.

in a straight line, move either from one side to the other, or coil
or curve about an imaginary axis. This spiral movement is
known as circumnutation and is characteristic of twining stems and
tendrils, as the hop vine and tendrils of Bryonia ( Fig. 181 ) . Nuta-
tion curvatures are due to unequal growth on two sides of the
organ and cease when there is a cessation in growth or when
the plant has reached maturity.

The movements of organs due to external stimuli are usually
in a direction which shows a relation to the direction of the stim-
ulus, as those produced by gravity and light (Fig. 207), and these

FIG. 207. American senna (Cassia marilandica). The figure at the left shows the pin-
nately-compound leaves in the day position when under the influence of light, and the one
to the right the drooping position of the leaflets at night.

movements are of use in bringing the organs into more favorable
positions for growth. Stimuli of this kind are spoken of as
orienting or TROPIC. The compound leaves of a number of plants
exhibit in addition certain variable and periodic movements, which
have their origin in a special mechanism known as the PULVINIS.
The pulvinis appears as a swelling on the petiole and consists of
parenchymatous tissue which is highly turgid, i.e., full of water.
Any stimulus, such as mechanical shock, which causes a differ-
ence in the degree of turgidity on two sides, will result in a move-
ment of the leaves in such plants as Mimosa, Oxalis and locust.
The leaves of Mimosa pudica, a common cultivated sensitive plant,
show a very rapid response to such stimuli, the leaflets folding

MORPHOLOGY OF HIGHER PLANTS.

361

together and the petiole and petiolules drooping. In other cases
there is a change in the position of the leaves following the alter-
nations of day and night. During the day the leaflets are spread
out freely, but at night or in darkness they droop and fold
together. These are spoken of as nyctinastic (nyctitropic) or
" sleep movements," and are exhibited by a number of leguminous
plants, as clover, bean, Cassia (Fig. 207), and by wood-sorrel
(Oxalis Acetosella) and various cultivated species of Oxalis. The
leaves of Oxalis as well as of some other plants fold together

II

FIG. 208. So-called carnivorous plants. I, the pitcher plant (Sarracenia Purpurea)
showing the modified pitcher-like leaves (A) with inflated portion which narrows into the
petiole, and a terminal, more or less spreading winged portion; and a flower and flower-bud
(B). II, three species of sundew: A, Drosera rotundifolia; B, D. intermedia; C, D.
longifolia. — I, after Gray; II, after Drude.

under the influence of intense light as well as at night or when
the amount of light is reduced. Of special interest also are the
lateral leaflets of Desmodium gyrans (telegraph plant) which
describe curvatures at more or less regular intervals day and
night when the temperature is favorable. The leaves of the sundew
(Drosera) are remarkable for their sensitiveness to touch. The
upper surface and margin are provided with peculiar hairs or

362

A TEXT-BOOK OF BOTANY.

tentacles (Fig. 208, //) which when touched, as by an insect,
gradually curve inward. Not only this', the stimulus may be trans-
mitted to other tentacles and sometimes even the blade itself may

FIG. 209. Flowering plant of Venus's Flytrap (Dioneea muscipula) of North Carolina,
showing the sensitive armed leaves both open and closed, in one of which an insect has been
imprisoned. — Drawn from nature by Florence Newton.

roll inward to some extent, thus entrapping small insects which
serve as food to the plant. The leaves of a related plant Dioncea
are even more sensitive and when special hairs on the blade are
touched that part of the lamina bearing these hairs closes with a

MORPHOLOGY OF HIGHER PLANTS.

363

quick, trap-like movement, imprisoning its insect prey (Fig. 209).
Phyllotaxy, or phyllotaxis, is the study of the distribution
of leaves upon the stem, and of the laws which govern it. If we
examine germinating plants of the beech, the elm, or the oak, we
observe that, while the seed-leaves are opposite to each other, the
subsequent leaves are arranged according to a different order in
these several plants, but in a definite manner in each. In the elm,
the distribution of the leaves is such that the third leaf is directly
above the first; in the beech, the fourth leaf is above the first, and
in the oak, the sixth leaf is above the first. If these leaves are con-
nected in the order of their development, it will be seen that they
describe a spiral in their arrangement, and it will also be found
that one or more circuits of the stem are made between the super-
imposing leaves. Furthermore, it will be found that this arrange-
ment constitutes a mathematical series which may be expressed
in degrees, or the parts of a circle that the leaves are from each
other, this measure being known as DIVERGENCE; or by the number
of perpendicular rows of leaves on the stem, which are known as

ORTHOSTICHIES.

The following may serve to illustrate the terms used :

LEAVES.

DIVERGENCE.

ORTHOSTICHIES.

Degrees.

Parts of a Circle.

Elm . ....

1 80
120
144

fc
i
t

Distichous
Tristichous
Pentastichous

Beech

Oak

If we examine the fractions used, we will find that the numer-
ator indicates the number of turns around the stem before encoun-
tering a superimposed leaf, and that the denominator indicates
the number of leaves found ; the latter also expresses the number
of orthostichies. On adding the numerators and denominators of
any two successive fractions, a fraction is obtained which ex-
presses the next highest arrangement, as

In quite a number of plants two leaves arise at the nodes, as
in the Labiatse. These are invariably situated opposite each other

364 A TEXT-BOOK OF BOTANY

on the stem, and the successive pairs alternate with one another,
forming the decussate arrangement of leaves (Figs. 180, i8'i, 184).

Modified Leaves. — Leaves are variously modified and serve
for other purposes than those already described. They may be
fleshy in character and serve as storehouses for nutritive material,
as the seed-leaves of the oak, or they may serve for the stor-
age of water, as in Agave, Aloe and succulents. In some instances,
particularly when situated near the flowers, they lose their green
color, as in the dogwood, skunk cabbage and others. In other
cases they are modified so that they serve as a trap for insects,
as in Dioncca, Sarracenia and Drosera (Figs. 208, 209). The peti-
ole may become enlarged and perform the functions of the leaf, as
in the Acacias of Australia ; or it may become bladder-like and
servers a means for floating the plant, as in the water hyacinth.
The stipules may likewise be modified, becoming leaf-like, as in the
pansy (Fig. 201 ) ; or metamorphosed into thorns, as in the locust ;
or clasping, as in Polygonum. In some cases the leaves are very
much reduced, their functions being performed by the stem, as in
Cactacese, or even by the roots, as in some orchids which have
assimilating roots.

Prefoliation or vernation is the disposition of leaves in the
bud. The terms used to describe the folding of the leaves in the
bud are derived from an examination of transverse sections of
the bud. The following are some of the terms which are em-
ployed: CONDUPLICATE, when the lamina of the leaf is folded
lengthwise along the midrib so that the two halves of the upper
surface lie together, as in the Magnoliaceoc ; PLICATE or plaited,
when the lamina is folded along the veins, like a closed fan, as in
the maples ; CONVOLUTE, when rolled lengthwise and forming a
coil in cross section, as in the Rosacece; INVOLUTE, when both mar-
gins are inrolled lengthwise on the upper surface, as in the violets ;
REVOLUTE, when both margins are inrolled lengthwise on the lower
surface, as in Azalea.

In addition, there are several terms used which are derived
from the appearance of the bud, as RECLINATE or inflexed, when
the upper part is -bent on the lower, as in Liriodendron ; and
CIRCINATE, when the upper part is coiled on the lower so that the
tip of the leaf is in the center of the coil, as in the ferns.

MORPHOLOGY OF HIGHER PLANTS. 365

THE INNER STRUCTURE' OF THE LEAF

In all green leaves the typical structure is as follows : A cuticle
covers the outer cell-wall of the epidermis, while the epidermis
itself shows much of the same modifications as exist in the stem ;
frequently the lumen of the cells of the epidermis is wider on the

FIG. 210. Group of transplanted wild plants showing variation in form of leaves.
A, Cinnamon fern (Osmunda cinnamomea) showing sporophylls (fertile leaves) and a cluster
of pinnatifid sterile leaves, the pinnae being linear-lanceolate and deeply pinnatifid; B,
wild ginger (Asarum canadense) showing basal, reniform, long-petiolate leaves with cordate
base and slightly pointed apex; C, young hickory (Hicoria ovata) showing the odd-pinnate
(impiri pinnate), 5- to 7-foliate leaves; D, ternate, decompound leaf of Virginia grape fern
(Botrychium virginianum) ; E, digitately compound leaves of cinquefoil (Potentilla).

ventral face than on the dorsal. Hairs abound on the leaves in
many plants, and stomata are especially frequent on the dorsal
surface. The upper epidermis may further be characterized by
the presence of water-pores, the origin and function of which have
already been described (Fig. 147).

366

A TEXT-BOOK OF BOTANY.

The green chlorophyll-bearing tissue is called CHLORENCHYMA
(frequently spoken of as mesophyll), and is frequently differen-
tiated into a ventral PALISADE TISSUE, composed of long cells
which are placed vertically to those of the epidermis; and a
DORSAL PNEUMATIC TISSUE, made up of irregularly branched or
lobed cells with very large intercellular spaces. Secretory cells or
receptacles occur in the chloTenchyma of many plants and corre-
spond with those found in the cortex of the stem. When the
palisade tissue occurs on both faces of the leaf blade with the pneu-

ST-

FIG. 211. Transverse section of midrib of leaf of stramonium: EU, upper epidermis;
CO, collenchyma; PA, palisade cells; O, layer of cells containing rosette aggregates of
calcium oxalate; M, loose mesophyll; EL, lower epidermis; OP, prisms of calcium oxalate;
OS, sphenoidal micro-crystals of calcium oxalate; ST, stoma; T, tracheae; SU, leptome or
sieve on upper side of tracheae or vessels; SL, sieve on lower side of tracheae, this arrange-
ment of leptome or sieve and tracheas forming bicollateral fibrovascular bundles.

matic tissue in the center, the leaf is called " unifacial " or " iso-
lateral " (Figs. 211, 215) ; otherwise the leaf is said to be " bi-
facial " or " dorsiventral," i.e., with two distinct surfaces.

Mechanical tissues, as collenchyma and stereome, are frequent
and these accompany the veins as hypodermal strands, being best
developed usually on the dorsal face of the latter, as underneath
the leptome. The mestome-strands of the leaf blade generally
lie in a single plane. They are collateral and have the leptome
situated towards the dorsal face. They are nearly always sur-

MORPHOLOGY OF HIGHER PLANTS.

367

rounded by thin-walled PAREXCHYMA-SHEATHS, or as in several
grasses and sedges by thick-walled mestome-sheaths. In some
plants of various families, the midrib is not only stronger devel-

FIG. 212. Study of the stomata on leaves of Beta vulgaris: A and B, surface sections
of the leaf, and C and D, transverse sections of the stomata. In A and C, the stomata
are shown with the guard cells (s) distended and the pore (sp) open to allow the passage of
vapors and gases. B and D, showing the pore or opening closed due to the plasmolysis
of the contents of the guard cells, the internal pressure or tension having been relieved.
e, epidermal cells; a, large cavity or intercellular space beneath stomata; and m, loose
mesophyll cells with chloroplasts. — After Frank.

oped than the lateral veins, but it may be composed of several,
instead of only one, mestome-strand, sometimes representing a
true stele.

368

A TEXT-BOOK OF BOTANY.

The petiole generally shows the structure of the midrib as far
as concerns the mestome-strands, but possesses furthermore a
more or less strongly developed parenchyma, the cells of which

FIG. 213. Development of stomata on leaves of Sedum purpurascens: in A very
early stages of growth, and B nearly completed stoma. In B are shown a stoma with two
guard cells, three neighboring cells and two of the epidermal cells (e) ; the numbers in B
correspond to those in A and show the origin of the several cells from the division of a single
epidermal cell. — After Sachs.

are colorless, thin-walled and which may often be traced to the
leaf-blade itself, where it surrounds the stronger veins, causing

FIG. 214. Transverse section through a stomata showing how by a slight difference
in the tension the pore is either opened or closed; the dark lines show contour of cells
when open, the light lines show when they are closed. — After Schwendener (See Haberlandt,
Physiologische Pflanzenanatomie).

them to project as ribs and to be much thicker in cross-section
than the adjoining chlorenchyma.

From a histological point of view the leaf structure of

MORPHOLOGY OF HIGHER PLANTS.

369

Dicotyledons resembles very closely that of the Monocotyledons,
except that in the latter the palisade-cells often radiate towards
the center of the mestome-strands. There are, however, many
instances of a similar development in the leaves of Dicotyledons.
Abnormal structures are common in leaves, especially in such

FlG. 215. Transverse section of leaf of Phytolacca decandra showing upper epidermis
(ue), palisade cells (p), raphides (r), spiral tracheae (v), loose mesophyll (m) with large
intercellular spaces, and lower epidermis (le) with a stoma.

as are not held in a horizontal position, but vertical, as those of
Eucalyptus, the Irideae, etc.

The Epidermis forms the surface of the leaf and may con-
sist of one or more layers of cells. The outer walls are cutinized,
and when nearly smooth the leaf is said to be GLABROUS. They
may be covered or whitened with a bloom, as in magnolia, when
24

370

A TEXT-BOOK OF BOTANY.

the leaves are spoken of as GLAUCOUS. In other cases the outer
walls of the epidermal cells are modified to hairs (Figs. 100, 124,

125, I4&-I55)-

ANATOMICAL DIFFERENCES IN LEAVES. — The walls of the
epidermal cells, although usually isodiametric, are often very
zig-zag in outline. In size, the upper epidermal cells are usually
larger in a given species than those of the lower surface, and
sometimes are rather linear, resembling a palisade layer. The

FIG. 216. A, transverse section of leaf of Lobelia inflata showing the large irregular
epidermal cells (e), palisade cells (p), trachea (t), loose parenchyma (m), and lower epider-
mis (i). B, transverse section of leaf of Matico showing oil-secretion reservoir (o), upper
epidermis (e), lower epidermis (1), with non-glandular hairs (h), palisade layers (p), loose
mesophyll (m).

cuticle may be thin or leathery and tough, and sometimes is pro-
vided with minute ridges or crests, especially on the under sur-
face, thereby giving a dull appearance to the leaf. Many leaves,
too, excrete wax on the surface and consequently have a glaucous
or hoary appearance, notably some of the poppies, the common
jewel-weed and many others. Other modifications may have
to do with the gelatinization of the epidermis of the leaf, assisting
in the storage of water, as in the leaves of the violets. The
differentiation in forms of calcium oxalate crystals is also im-

MORPHOLOGY OF HIGHER PLANTS. 371

portant in distinguishing plants that resemble each other. The
size and number of stomata as well as their distribution and
arrangement with respect to each other varies in different plants.
For example, in certain saprophytic or submerged plants the num-
ber of stomata is greatly or even completely reduced, and when pres-
ent are quite functionless. Sometimes the stomata are depressed

FIG. 217. Transverse section of leaf of Matico near two veins; showing the upper
epidermis of several layers (e), two layers of palisade cells (p), tracheae (t), sieve (s), collen-
chyma (c), loose parenchyma containing crystals of calcium oxalate (ca), and non-glandular
hairs (h).

below the surface of the leaf, this being true in plants occurring
in dry or cold districts, and is distinctly characteristic of many
Coniferse.

There is a marked difference in the arrangement of the pali-
sade tissues, the following types being distinguished : i. In bifacial

372

A TEXT-BOOK OF BOTANY.

N

FIG. 218. Digitalis leaves: A, transverse section near one of the veins showing the
separated or extra-epidermal layer occurring on the lower surface (S) with two non-glandular
hairs (N) and glandular hair (G), epidermal layer (E), lower epidermis (LE), chlorophyll
layer (M), upper epidermis (UE), and tracheae (T). B, transverse section of portion of
leaf showing the separated or additional epidermal layer; c, collenchyma.

or dorsiventral leaves the palisade cells are distributed only below
the upper epidermal layer (Figs. 211, 215). 2. In unifacial or

MORPHOLOGY OF HIGHER PLANTS. 373

isolateral leaves the palisade cells occur beneath the epidermal
layers of both leaf surfaces, as in senna. 3. In some leaves, as
in Eucalyptus, the entire parenchyma is made up of palisade
cells. 4. In a few leaves there is no differentiation of a palisade
layer, and these are sometimes referred to as centric leaves. The
palisade cells may contain not only chloroplastids but crystals of
calcium oxalate (Fig. 215), tannin-inclusions (Fig. 114), etc.
Distributed among the palisade cells may be the oil-secretion
reservoirs (Fig. 216, B). Furthermore, the palisade cells may
be of equal length or the stratification may be quite uneven and
irregular. In shape they may vary from long, narrow cells to
short, broad cells. In some special instances they are narrowed
at the lower end in the form of a blunt cone forming the so-called
" funnel cells," which are especially characteristic of plants in-
habiting moist localities. There is still another common form
known as arm-palisade parenchyma, in which the cells are branch-
ing and connected with each other by means of the branches.
Tissues of this type occur in the Equisetacese, Filices, Coniferse,
Graminese, and in a number of Dicotyledons, such as Aconitum,
Adonis, Anemone, Caltha, Clematis, Delphinium, Nigella, Pseonia,
and Trollius in the Ranunculacese ; Sambucus and Viburnum in
the Capri foliacese; Lysimachia and Trientalis in the Primulacese.
The spongy tissue or dorsal pneumatic tissue shows consider-
able variation in the arrangement and shape of the cells. In some
leaves the cells are arranged in strata or layers, while in others
they are more or less irregular. The cells may be spherical or
provided with a number of arms, the latter developing parallel
to the surface of the leaf or radiating in any direction, thus caus-
ing a variation in the nature and size of the intercellular spaces.
In some instances there are included in the mesophyll certain
mechanical cells, of which the simplest are like ordinary stone
cells. They may be more or less elongated or branched or even
quite fibrous, and are known as SPICULAR CELLS. The latter are
sometimes quite prominent when they traverse the leaf in a verti-
cal direction, giving rise to translucent spots. Spicular cells have
been found in the mesophyll of quite a number of families. They
are quite characteristic, although absolutely not constant, in the
^genuine tea leaf (Thea sinensis).

374 A TEXT-BOOK OF BOTANY.

IV. OUTER MORPHOLOGY OF THE FLOWER.

It is well known if the stem of a plant, as the carnation, rose,
geranium, etc., be cut into pieces so that each portion has at least
one node and placed under suitable conditions for growth, roots
will arise from the nodes that are in the ground and a new plant
will be developed. The same result can be achieved if plants like
Ficus, growing in a greenhouse, have placed around the nodes near
the tip of the branches a clump of sphagnum, and if the latter
be kept moist roots will arise from the joints. This method of
increasing the number of individual plants, while it is limited to
certain perennials and cannot be followed with annuals or bien-
nials, is frequently resorted to by horticulturists, and is known
as vegetative propagation. The production of independent plants
in this manner is dependent upon the property of the meristematic
cells in the pericycle of the stem to produce the meristems that
give rise to the tissues of the root. As this process of propagation
for plants growing in temperate regions and in cold climates would
be more or less uncertain for the perpetuation of the species, it
is fortunate that in Nature safer methods of reproduction are
followed, depending upon the development of flowers and the
production of seed. In the latter there is a young plant with all
of the elements of root and shoot contained therein and so pro-
tected by a seed-coat that it may withstand extremes of climatic
conditions, as well as the various hostile forces to which it might
be subjected.

THE FLOWER is a shoot which has undergone a metamorphosis
so as to serve as a means of propagating the individual. It is
an unb ranched and definite shoot, or an apex of a shoot. It
might be termed a " dwarf-branch " that dies and drops off the
plant after the maturation of the fruit. The most complete
flower has four kinds of leaves: sepals, petals, stamens, and
carpels.

The sepals, usually green and leaf -like, make up the outer
spiral known as the calyx. The petals being frequently highly
colored form an inner spiral known as the corolla. The stamens
are the polliniferous organs of the flower, and the carpels bear
the ovules which later develop into seeds.

While the flower is a very complicated structure in many

MORPHOLOGY OF HIGHER PLANTS. 375

cases, the definition given it by some writers is very simple. It
is defined as a branch which bears sporophylls. As we have
seen, a sporophyll is a leaf which bears sporangia. According to
the definition given, the strobiles or cones of the Gymnosperms
and certain Pteridophytes, as the horsetails and club mosses,
are entitled to rank as flowers. In Angiosperms other leaves may
be present, and these are known as the FLORAL LEAVES. The
flower, then, in Angiosperms is made up of sporophylls which are
essential, and floral leaves which may or may not be present. But
in speaking of the sporophylls of the flower in Angiosperms it is
customary to use terms which were applied to them before their
relation to the similar organs in the Gymnosperms and Pterido-
phytes was understood. Thus the microsporophylls, as already
pointed out, are known as STAMENS, and the megasporophylls as
CARPELS.

For a great many years botanists taught that the stamens and
carpels are transformed foliage leaves, — in other words, that they
are derived from foliage leaves, — but in more recent years the
view has been established that they arise as independent members,
— are, in fact, as independent as the foliage leaves themselves.
Various transformations or modifications may and do occur, but
these are not confined to the foliage leaves alone, for under cer-
tain conditions the sporophylls may assume the character of floral
leaves.

It is true that in the case of some ferns the sporophylls bear
a strong resemblance to foliage leaves, as in Dryopt-eris Filix-mas
(Fig. 53), but this does not necessarily prove that the sporophylls
of Angiosperms are transformed leaves, but only that the further
back we go, the less the degree of differentiation of parts until
we reach the unicellular algae.

The flowers of the Angiosperms differ from those of the
Gymnosperms in that the ovules (megasporangia) are enclosed,
before pollination, in an ovary which has developed a special
organ — the stigma — for the reception of the pollen grains (micro-
spores), and the floral envelopes are much more conspicuous.

The several parts of the flower are arranged more or less
compactly at the terminus of an axis known as the flower branch,
the special portion bearing these parts being known as the TORUS

376 A TEXT-BOOK OF BOTANY.

(sometimes spoken of as the receptacle), and that portion below
the flower proper as the flower stalk (Fig. 78, PE). The carpel
or carpels occupy the terminal portion of the branch, while the
stamens and floral leaves occur in circles or whorls below.

Pistil. — There may be only one carpel present in a flower,
or there may be more. In the latter case the carpels may remain
distinct or they may be united, but, whatever the number or the
degree of union, it is the carpel or carpels which constitute the
closed structure known as the pistil. The pistil is usually differ-
entiated into three quite distinct regions: (i) A lower bulbous
portion which contains the ovules, known as the OVARY; (2) a
neck-like portion known as the STYLE; and (3) at the top of
the style a specialized portion which receives the pollen, known
as the STIGMA (Figs. 78 and 219). When the pistil is made up
of a single carpel it is said to be SIMPLE, and when composed
of more than one carpel it is called COMPOUND.

The carpels in the compound pistil appear to be united in
different ways. Sometimes they appear to have coalesced or
grown together at the margins, thus forming an ovary with but
one chamber or compartment ( Fig. 223, B ) . In the other cases the
carpels appear as though they were incurved or folded together at
the margins along the line of union, thus forming septa or walls
which divide the inner cavity into several compartments or
locules (Fig. 223, A, C).

When the carpels are not united but remain separate, there
are as many pistils as carpels, as in the flowers of buttercup (Fig.
223, D) . Thus a unilocular ovary may belong to a simple or com-
pound pistil.

GYN^ECIUM. — The aggregate of pistils in a flower constitutes
the gynsecium. If the gynsecium is made up of a number of simple
pistils, as in the flower of buttercup (Fig. 223, D), it is said to be
APOCARPOUS. But if the carpels are united into one structure, then
the gynsecium is said to be SYNCARPOUS, as in the orange flower,
which is in reality equivalent to a compound pistil. Inasmuch as
the styles and stigmas are frequently not united, the expression
compound ovary is usually employed. According as the gynse-
cium consists of one, two, three, or many carpels, it is said to be
monocarpellary, dicarpellary, tricarpellary, or polycarpellary.

MORPHOLOGY OF HIGHER PLANTS.

377

The pistil of the flower of the pea is simple and has an elon-
gated ovary, and upon dissecting the ovary and also making a
transverse section of it, it is observed that the ovules are borne
upon the part which projects from the concrescent margins into the
cavity, this part being known as the PLACENTA, and the united

J " (/ H

FIG. 219. Pistils and different kinds of stigmas. A, simple (monocarpellary) pistil
of willow with lobed stigma; B, compound pistil of Fourcroya with head-like stigma; C,
longitudinal section through flower of Spondias with five separate styles and stigmas,
only three of which are shown; D, flower of Peperomia showing bristly stigma; E, recurved,
thread-like stigmas of the Upas-tree (Antiaris); F, flower of a Canary grass showing the
two simple plumose stigmas; G, pistillate flower of couch grass showing the two compound
plumose stigmas; H, thread-like stigmas of pistillate inflorescence of Euchlawa one of
the grasses; J, tri- parted stigmas of the pistillate flower of the castor-oil plant; K, L,
two forms of stigmas of Begonia. — After Engler.

margins of the carpel forming the " inner " or VENTRAL SUTURE.
In the syncarpous gynaecium the ventral suture of the carpels is
directed toward the axis of the flower ; in some cases that portion
of the carpel corresponding to the midrib is very prominent, as
in the Papilionatse, and has received the name of " outer " or

DORSAL SUTURE.

There are as many locules in the ovary as there are carpels,

378 A TEXT-BOOK OF BOTANY.

and the walls or partitions between the locules of a syncarpous
gynaecium are known as DISSEPIMENTS; when three or more
carpels are united the number of dissepiments corresponds to the
number of carpels. It sometimes happens that a partition or wall
is intruded from the mid-vein of the carpel, dividing a unilocular
ovary into one that is bilocular, as in species of Astragalus, and
such a partition is termed a FALSE DISSEPIMENT.

When no other than the true dissepiments exist in the syn-
carpous gynaecium the placentas are borne along the axis of the
flower and are termed axial placentas. In the Caryophyllaceae
the ovules are borne upon a central axis, and the dissepiments
having been absorbed by the gynaecium is said to possess a free
central placenta. In other cases the placentas grow backward
from the central axis toward the mid-vein of the carpel, carrying
the ovules with them, when they are spoken of as parietal pla-
centas, as in colocynth fruit and watermelon.

The STYLE not only varies in shape and size but in the manner
of attachment to the ovary (Fig. 219) ; it may be very short, as in
the clove; long and filiform, as in (Enothera; club-shaped (clav-
ate), as in the orange; or broad and petalloid, as in Iris. It is
usually situated at the summit of the ovary, when it is said to be
apical or terminal ; it may, however, be laterally attached, as in
the strawberry, or, as in a few instances, attached to the base of
the ovary. It is usually smooth, but may be hairy, as in the Com-
positae. The styles, like the carpels, may be separate or united,
and in the latter case may have a central canal connecting the
stigma with the ovary, as in the violets. While usually deciduous,
the style may be more or less persistent — forming a part of the
fruit — or even become much elongated, as in the dandelion.

The STIGMA is an essential part of the pistil in that it is the
germinating surface for the pollen grains, it being viscid and espe-
cially adapted for this purpose (Fig. 219). The stigmas may be
separate, as in the Compositse, or they may be united into a more
or less club-shaped or globular head, consisting of as many lobes
as there are stigmas, as in the poppy. The stigma, while usually
solid, may have an opening, as in the violets, which sometimes has
a lid-like appendage, as in Viola tricolor.

The OVULES (Fig. 219), as we have already seen, are small

MORPHOLOGY OF HIGHER PLANTS.

379

bodies which are borne on the placentas, and which, after fertiliza-
tion, develop into seeds. The number of ovules varies considerably
— there may be but one, as in the almond, or there may be a large
number, as in the watermelon.

There are several principal forms of ovules (Fig. 220) recog-
nized, of which the following may be mentioned : ( i ) ATROPOUS,
in which the ovule is straight and erect on its stalk, as in the
Urticacese; (2) AN ATROPOUS, in which the ovule is bent over on to
the stalk so as to be in an inverted position, the line of attachment
of the ovule and stalk being known as the raphe (Fig. 230, n) ; (3)
CAMPYLOTROPOUS, in which the ovule is bent upon itself, as in
Stramonium, this form being less frequent than the other two.
Most of the ovules of flowering plants are anatropous.

FIG. 220. Three positions of ovules. A, atropous; B, anatropous; C, campylotropous.
(f) funiculus or stalk; (c) chalaza, or point of union of nucellus and integuments; (k) nucellus
or megasporangium; (em) embryo-sac or megaspore; (ai) outer integument; (ii) inner
integument; (m) foramen or orifice for entrance of pollen tube, known as the micropyle
in the seed; (r) raphe.— After Prantl.

Stamen. — As already indicated, the stamen consists of a
stalk-like portion called the FILAMENT, and a specialized portion
which bears the sporangia, called the ANTHER (Fig. 78). The
filament may be long or short or wanting. It is commonly thread-
like, but varies considerably, and is sometimes leaf-like.

The ANTHER is the essential part of the stamen (Fig. 221)
and consists of two lobes, each of which is composed of two divi-
sions or pollen sacs (Fig. 79). These sacs contain the pollen,
which is commonly discharged either through a longitudinal suture
or line of dehiscence, or through an opening at the tip. The
anthers may be variously attached to the filament (Fig. 221).
When they face the axis of the flower they are said to be INTRORSE,
as in the Violacece, and when they face the perianth they are said

A TEXT-BOOK OF BOTANY.

FIG. 221. Different types of stamens. Abbreviations: filament (f), pollen sacs or
iheca (sporangia) (th), connective (c). A, stamens of a water lily (NymphoBO) showing
variation in the stamens (a-d) ; B, theca near middle of the stamen of Popowia; C, anther of
another species of Popowia with fleshy connective and pollen sacs on either side; D, stamen
of Tradescantia with transverse connective; E, F, G, stamens of several Commelinaceae
with broad connectives; H, stamen of Salvia with peculiar swinging connective and an
aborted pollen sac or staminodium (std) at the lower end and the fertile pollen sac above;
J, peculiar elongated connective of Unona; K, elongated connective of Humiri; L, .andrce-
cium of violet showing two spurred sessile stamens; M, stamen of Columelia with sinuous
confluent anthers, broad connective and short filament; N, confluent transverse pollen
sacs of Arisarum; O, united pollen sacs of Columbine showing small connective; P, spherical
pollen sacs of C alia, with slightly developed connective; Q, versatile anther and long, slen-
der filament of dead nettle (Lamium album) ; R, dehiscence of anther of Solanum by means
of terminal pores; S, spurred anther of Arbutus with terminal pores; various kinds of val-
vular dehiscence, as in Berberis (T), Atkerosperma (U) and Persea (V). — A, after Caspary;
B, H-R, U, V, after Baillon; S, T, after Sachs; D-G, after Schonland.

to be EXTRORSE, as in the Magnoliacese ; when they lie horizontally
on the tip of the filament, so that they swing as on a pivot, as in
the tiger lily, they are said to be VERSATILE ; when they adhere

MORPHOLOGY OF HIGHER PLANTS. 381

longitudinally to the sides of the filament and the dehiscence is
marginal, they are said to be INNATE; when they adhere longi-
tudinally to the filament and the latter extends slightly beyond
them, they are said to be ADNATE, in which case they may be
extrorse or introrse. In some of the Labiatae the lobes of the
anther are united at the apex of the filament, but diverge from the
point of attachment and are said to be connate, coherent, or

CONFLUENT.

The CONNECTIVE is that portion of the filament to which the
lobes of the anther are attached or which connects them (Fig.
221 ); usually it is not very prominent ; but in some of the Labiatae,
as in Salvia, it is rather broad ; in some of the Malvaceae it is
entirely wanting, the two lobes being confluent ; in other cases it
may be extended beyond the lobes of the anther, as in species of
Asarum.

APPENDAGES OF ANTHER. — In certain instances the anthers
are appendaged (Fig. 221) : In the violets there is a triangular
growth at the apex ; in the oleander the apex is plumose ; in deer
berry (V actinium stamineum) there are two awn-like append-
ages upon the back of the anther; in the violets the two stamens
that project into the spurred petal are also spurred and secrete a
nectar; in the Asclepiadaceae the anthers possess wing-like ap-
pendages, each sac or division of which contains a pear-shaped
coherent mass of pollen grains (pollinium).

When a flower has but one stamen it is termed MONANDROUS ;
and when there are two, three, or many stamens, it is said to be
diandrous, triandrous, or polyandrous (Fig. 223). The aggregate
of stamens in the flower is called the ANDRCECIUM. In the Labi-
atae there are four stamens arranged in a longer and shorter pair,
and the stamens are said to be DIDYNAMOUS ; in the Cruciferae
the flowers possess six stamens, four of which are longer than the
other two, and the stamens are described as TETRADYNAMOUS ;
in some plants, as in the Lobeliaceae, Papilionatae, etc., the fila-
ments cohere, forming groups (Fig. 222) which are termed mona-
delphous, diadelphous, etc. ; in the flowers of the potato the
anthers lie close together but are not united, forming apparently
a continuous ring or band around the pistil, when they are said
to be connivent ; in the tubular flowers of the Composite the

382

A TEXT-BOOK OF BOTANY.

anthers are united, forming a closed ring, and the stamens are
spoken of as SYNGENESIOUS (Fig. 222, A) ; in many of the Cucur-
bitacea the filaments and anthers both are confluent ; in the flowers
of the Orchidaceae the stamens are borne upon the pistil and are
said to be GYNANDROUS.

Floral Envelopes. — As their name indicates, the floral en-
velopes occupy the outermost or lowest position in the arrange-
ment of the parts of the flower. In the bud condition they protect
the essential elements, and in the expanded flower are considered
to play an important role in securing pollination through the
visitation of insects. The floral envelopes are made up generally
of two kinds of leaves, petals and sepals (Figs. 224 to 227).

FIG. 222. Union of stamens. A, united anthers of flower of Composite; B, diadelphous
stamens of Pisum with i free stamen and 9 united; several types of monadelphous
stamens, as in Erythroxylon (C), Melia Azedarach (D), and common mallow (E).— After
Baillon.

The PETALS form a spiral which surrounds the androecium.
They are, as a rule, quite bright and attractive, being frequently
highly colored, as in the rose, Fuchsia, violet, etc., and are known
collectively as the COROLLA.

The SEPALS form the next and lowermost spiral. They are
usually green and leaf-like, as in the rose and carnation, and
together constitute the CALYX. Sometimes the corolla and calyx
are spoken of together as the PERIANTH, although, strictly speak-
ing, the term has a more special application, and is used mostly in
speaking of the sepals and petals of monocotyledonous flowers,

MORPHOLOGY OF HIGHER PLANTS.

383

these parts being much alike and not distinguishable, save in posi-
tion, as in certain lilies.

FIG. 223 Types of flowers: A, hypogynous flower of flax; B, perigynous flower of
cherry, showing perianth tube with sepals, petals and stamens on its border; C, epigynous
flower of American sarsaparilla ; D, flower of buttercup showing apocarpous gynaecium
and large conical torus; E, irregular (bilateral or zygomorphic) flower of aconite
showing half of helmet-like sepal (a), other sepals (b, c), long-clawed nectary (k) developed
from one of the posterior petals, separate pistils (f); P, corolla of Salvia spread open and
showing the two rudimentary stamens and two fertile stamens. The connectives in the
latter are long and filamentous and each bears at the upper part a normal pollen sac and
at the lower end a non-fertile enlarged portion which the insect pushes against in entering
the flower and thus causes the pollen to be deposited on its back. — A-C, aftei Gray; D-F,
after Wanning.

When the divisions of the calyx and corolla remain separate
and distinct the latter are spoken of as CHORISEPALOUS and CHORI-
PETALOUS, respectively; but when the divisions are united or

384

A TEXT-BOOK OF BOTANY.

FIG. 224. Lobelia inflata: A, upper portion of shoot showing the dentate-denticulate
leaves, the bracted racemes with flowers and inflated capsules, the latter developing soon
after fertilization; B, flower showing linear calyx teeth and 2-lipped corolla, the upper
lip with 2 rather erect lobes and the lower lip spreading and 3-cleft; C, longitudinal section
of flower showing the ovary with ovules (o), style (s), hairy bifid stigma (t) , united stamens
(a), corolla (p) and calyx (c) ; D, longitudinal section of stamen showing the hairy summit.

Scutellaria pilosa: R, branch showing crenate leaves and helmet-shaped capsular
fruits; F, capsule after dehiscence showing nutlets (n). G, section of flower of Scutellaria
lateriflora showing calyx (c) with crest on one side, 2-lipped corolla (p), the didynamous
stamens (s), and 4-locular ovary (n).

Spearmint (Mentha spicata}: H, showing flowers in slender interrupted spikes; J,
flower with bell-shaped calyx, tubular corolla and 2-lobed stigma; K, ellipsoidal pollen
grains.

MORPHOLOGY OF HIGHER PLANTS.

385

coalesced the calyx and corolla are called GAMOSEPALOUS (syn-
sepalous) and GAMOPETALOUS (sympetalous), respectively.

When the divisions of the calyx or corolla are entirely united
these elements are said to be ENTIRE, and when the divisions are

FIG. 225. Flowers of Solanaceae. Solatium carolinense: A, portion of shoot showing
a short raceme of flowers and the spinose leaves and stems; B, diagram of cross section
of flower showing sepals (s), petals (p), stamens (a) and ovary (c); C, longitudinal section
of flower, the letters the same as in B; D, stamen showing terminal pores; E, two spheroidal
pollen grains; F, cross section of 2-locular berry.

Hyoscyamus mulicus: G, section of flower showing calyx (c), lobed corolla (p), stamens
inserted on corolla tube (s) and ovary (o) bearing at the summit a long style; H, pollen
grains in different views; J, portion of stalk with fruits showing cylindrical calyx, the
fruit really being enclosed within the calyx and in the nature of a pyxis.

partly united they are spoken of as " toothed/' " lobed," or
" parted," according to the degree of union.

In the flowers of the Cruciferae and Caryophyllaceae there is a

conspicuous stalk to each of the separate petals, which is known

as the UNGUIS or CLAW; while the upper outspreading portion is

known as the LAMINA or blade. In the gamosepalous calyx and

25

386

A TEXT-BOOK OF BOTANY.

the gamopetalous corolla the lower united portion is known as the
TUBE, and the upper outspreading portion as the LIMB or " border."
The form of the calyx and corolla is quite characteristic for a
number of important families. In the Compositae there are two
characteristic forms of corolla, namely, the tubular in the disk

FIG. 226. Apocynum androsami folium: A, portion of a flowering branch; B, a flower
showing the short calyx tube and the corolla with more or less spreading lobes; C,' longi-
tudinal section of flower: c, calyx teeth; p, corolla lobes; a, anthers; and p, ovary; D,
single stamen with long spurs (s). E, a flower of A. cannabinum showing the corolla with
ascending lobes.

flowers and the ligulate in the ray flowers; in the Papilionatae
the corolla, from its fancied resemblance to a butterfly, is de-
scribed as PAPILIONACEOUS (Fig. 221, B) ; in the Labiatae the
petals are united into two lip-like divisions, and the corolla is said
to be BILABIATE (Fig. 223, F). There are two kinds of bilabiate

MORPHOLOGY OF HIGHER PLANTS.

•t

387

K

FIG. 227. Flowers of the Composites. Inula Helenium: A, ligulate floret; B, tubular
floret; C, achene with pappus; D, pollen grains; E, united anthers showing hooked hairs
(h) at the base.

F, tubular floret of Safflower (Carthamus tinctorius).

Dandelion (Taraxacum officinale): G, ligulate floret; H, one of the achenes showing
spreading pappus on a long stalk which develops after fertilization.

J, ligulate floret of Coltsfoot (Tussilago Far far a).

Marigold (Calendula officinalis): K, ligulate floret; L, one of the double hairs from
corolla, c, corolla; s, stamens; t, stigmas; p, pappus; h, hairs.

388 A TEXT-BOOK OF BOTANY.

corollas — one, as in lavender, where the mouth of the tube is open,
known as RINGENT ; and another, where the mouth is closed, as in
Linaria, called PERSONATE.

There are a number of other special forms of calyx and corolla,
particularly the latter, and of these may be mentioned the follow-
ing : A corolla, like that of the harebell, which is more or less bell-
shaped, is termed CAMPANULATE; a more or less campanulate
corolla contracted near the opening, as in Gaultheria, is spoken
of as URCEOLATE or urn-shaped ; in the morning glory and other
Convolvulacese the corolla is said to be INFUNDIBULIFORM or
funnel-shaped; a corolla in which the limb spreads abruptly from
the tube, as in Phlox and coffee, is termed HYPOCRATERIFORM
or salver-shaped ; a corolla with a short tube and outspreading
limb, as in potato, is said to be ROTATE or wheel-shaped ; a rotate
corolla with the margin more or less upturned is called CRATERI-
FORM or saucer-shaped ; in aconite the upper petal is hood- or hel-
met-shaped, and the corolla is spoken of as GALEATE ; in the violets
one of the petals has a spurred appendage and the corolla is de-
scribed as SACCATE or calcarate, while the modified petal in the
orchids is known as the LABELLUM.

DURATION OF CALYX AND COROLLA. — There is considerable
difference in the length of time that the calyx and corolla persist,
not only with reference to each other but in different plants. The
parts are said to be CADUCOUS when they drop from the flower as
soon as it opens, as the calyx of the poppy ; when they remain for
a day or so, they are said to be EPHEMERAL or fugacious, as in
the petals of the poppy ; in the rose and apple the petals fall away
soon after the pollen reaches the stigma and they are said to be
DECIDUOUS ; in some flowers the petals wither but persist until the
maturing of the fruit, as in the Droseracese, and are known as
MARCESCENT ; the calyx may remain unaffected until the maturing
of the fruit, as in the Labiatse, when it is said to be PERSISTENT.

Bracts. — In addition to the floral envelopes, other more or
less modified leaves are borne on the flower branch below the
flower, frequently at the base of the flower stalk, and these have
received the name BRACTS. The bracts closely resemble the foli-
age leaves, but usually are smaller and frequently are mere scales,
without chlorophyll. In some cases, however., they are large and

MORPHOLOGY OF HIGHER PLANTS. 389

showy, looking like petals (petaloid), as in the water arum (Fig.
263), the common dogwood; Bougainvillea and Poinsettia seen
in greenhouses.

The Torus constitutes the terminal portion of the flower
axis or stalk, and is usually more or less conical and somewhat
enlarged. When the torus is of this shape the parts of the flower
are inserted upon it in serial succession, all of the other parts
arising below the pistil. It may, however, be modified into a
hollow or cup-like structure which grows up around the ovary,
carrying the other parts of the flower (sepals, petals, and stamens)
with it, thus changing the relative position of the parts, although
it should be understood that the ovary occupies practically the
same position in the two cases.

When the torus is of the first type and the other parts of the
flower are inserted below the ovary, the flower is said to be HYPO
GYNOUS, as in the orange flower (Fig. 78, A) and the ovary
superior; but when the torns forms a cup-shaped receptacle and
the other parts of the flower arise on its margin above the ovary,
the flower is called EPIGYNOUS, as in the clove (Fig. 78, B ; 223 C)
and the ovary inferior. In other cases a ring of leaf-like tissue
arises from the torus, forming a cup-like receptacle or tube which
is known as the perianth tube, the sepals, petals, and stamens being
inserted on its margin. The perianth tube may be free from the
ovary, when the flower is said to be PERIGYNOUS and the ovary half
inferior or half superior, as in cherry (Fig. 223, B) ; or in the
case of an epigynous flower it may form a prolongation of the
cup-shaped torus.

Prefloration or estivation is the arrangement of the parts of
the flower — more especially the calyx and corolla — in the bud.
Some of the terms used in this connection are also employed in the
study of vernation. The following are some of the terms which
are employed: VALVATE, when the sepals or petals meet each
other at the edges, as in Malvaceae ; IMBRICATED, when the sepals
or petals overlap each other, as in the Magnoliacese ; PLICATE or
PLAITED, when the divisions are united and folded together, as in
the petals of Convolvulus and Datura.

The sepals and petals do not necessarily possess the same
arrangement, as in the Onagraceae, where the sepals are valvate

390 A TEXT-BOOK OF BOTANY.

and the petals are convolute. Furthermore, in addition to the
principal types of estivation and vernation already given, there
are a number of special modifications of these, depending upon
the number and arrangement as well as direction of the over-
lapping parts of the flower- or leaf-bud.

Coalescence and Adhesion. — Not only may the divisions of
the same circle or whorl of the flower be united, but even those
of different circles, and a number of terms are used to describe
these modifications.

When the divisions of the same circle are united there is said
to be a COHESION or COALESCENCE of the parts. When the divi-
sions of different circles are united, as of stamens with corolla,
the union is spoken of as ADHESION or adnation, as in Convolvulus.

Chorisis and Multiplication of Parts. — In contrast with the
reduction in number of parts of the flower due to union, there may
be an increase in the number of parts due to simple division or
splitting of the parts, and this is known as chorisis or deduplica-
tion. An illustration of this is furnished by the stamens of the
orange flower, where from a single initial stamen or primordium
a group of from 3 to n stamens may be produced. In other cases
there may be a multiplication in the number of parts from the
beginning, each part arising independently on the torus, as in the
stamens of rose. This, of course, would not be termed chorisis, as
no splitting or branching takes place.

Double Flowers. — In double flowers there is an increase
in the number of petals, which is considered to be due to the
methods of cultivation and the stimulus of an increased food-
supply. This results in several ways : ( i ) By transformation of
the sporophylls, more particularly the stamens, into petals; (2)
by division or chorisis of the stamens or carpels with subsequent
transformation into petals; (3) by division or branching of the
petals; and (4) by the production of new series of petals. The
extra petals in double carnations and double roses trace their
origin to the stamens, while in Fuchsia they are the result of
chorisis of the petals.

In the snow-ball (Viburnum Opulus) and hydrangea the essen-
tial elements have undergone a complete transformation, and the
flowers, while large and showy, are sterile. In the white water lily

MORPHOLOGY OF HIGHER PLANTS. 395

(Nyniphaa) there is a series of parts ranging from stamens with
narrow filaments and stamens with broad petaloid filaments to
petals tipped with a small anther and regular petals (Fig. 221, A).
In this case the stamens are considered to result from the trans-
formation of the petals. In the case of green roses and green
strawberry flowers the petals become green and leaf-like, and the
change is spoken of as CHLOROSIS or CHLORANTHY. In some
flowers even the ovules are replaced by leaf-like processes or
appendages, as in Drosera and clover.

Arrested Development. — The arrest or suppression of parts
of the plant, particularly of the flower, is of very common occur-
rence. Just as there are millions of seeds that never find suitable
conditions for germination, so in the flowers of a large number
of plants a very large proportion of the ovules never develop
into seeds, the plants in many instances not furnishing sufficient
nutriment for all of the ovules to mature. Under Leaves it
was stated that in the axil of each leaf there is a bud. This is
not always apparent, but if the plant be subjected to some special
stimulus, some of the latent buds will become evident. For
example, the rubber plant (Ficus), so commonly cultivated as an
ornamental plant, shows a tendency to develop a straight, un-
branched shoot, but if the tip of the shoot be cut off, the buds in
the axils of the upper leaves will develop into branches, while
some of those lower down will form small protuberances, but
develop no further. In other cases there is a loss of parts which
seems to be due to loss of function. When there is a partial loss
of the element, as of the anthers in the flower of catalpa, it is
said to be imperfectly developed or ABORTIVE. When the entire ele-
ment remains undeveloped, as in some of the stamens of the Labi-
atae, it is said to be SUPPRESSED (Fig. 223, F) . In flax the stamens
of the outer whorl are reduced to thread-like processes. Such
sterile or aborted stamens are called STAMINODES (staminodia).
In other plants the parts are not apparently arrested, but have not
yet been differentiated, as is the case in the Lily family, where the
perianth is composed of segments which are more or less alike
(Fig. 269). In other cases, however, there seems to be a suppres-
sion or arrest of the floral envelopes.

Cleistogamous Flowers. — In addition to the regular flowers

392 A TEXT-BOOK OF BOTANY.

some plants produce cleistogamous or closed flowers. In these
flowers the corolla is usually suppressed. The flowers develop
stamens and pistils but remain closed, and thus there is no chance
for cross-pollination. The cleistogamous flowers appear later
than the regular flowers and are more or less inconspicuous,
developing under the leaves and sometimes underground. Of the
plants producing cleistogamous flowers, the following may be
mentioned : various species of Viola, Polygala, etc.

Classes of Flowers. — As we have seen, the megasporophylls
and microsporophylls in the Gymnosperms are borne on separate
branches, thus giving rise to two kinds of flowers or cones. While
the separation of the stamens and pistils is exemplified in a
number of plants in the Angiosperms, still it is not the rule,
and these two elements are usually borne close together on the
same axis, — i.e., they both enter into a single flower structure.
Such a flower is said to be HERMAPHRODITE or bisexual, and most
of the conspicuous flowers are of this kind, as roses, buttercups,
lilies, etc. Inasmuch as the stamens and pistils constitute the essen-
tial elements of the flower, hermaphrodite flowers are also spoken
of as PERFECT, providing the stamens and pistils are capable of
exercising their generative functions. When the stamens and
pistils occur in separate flowers the flowers are said to be UNI-
SEXUAL or IMPERFECT, as in willow, oak, hickory, etc. A flower
having only a pistil or pistils is called PISTILLATE (Fig. 219,
A), while one having only a stamen or stamens is STAMINATE, as in
oaks. The staminate and pistillate flowers may be borne on the
same plant, when it is said to be MONOECIOUS, as in castor bean,
chestnut, -hickory, alder ; or they may be borne on separate plants,
when the plant is called DICECIOUS, as in willows and poplars.
Plants bearing hermaphrodite and unisexual flowers on the same
individual plant or on different individuals are called POLYGAMOUS,
as in Ailanthus.

A COMPLETE flower is one which possesses both kinds of essen-
tial elements and both kinds of floral envelopes, and is SYMMET-
RICAL when a plane can be laid in all directions, the parts being
alike, and when the number of parts in each circle is the same or
when the number in one circle is a multiple of that in the others ;
as a rule, the number of stamens is some multiple of one of the

MORPHOLOGY OF HIGHER PLANTS. 393

other parts, as in geranium (Fig. 223), where we find five sepals,
five petals, ten stamens, and five pistils.

Flowers are also spoken of as REGULAR or IRREGULAR, accord-
ing to whether all the parts of a circle are uniform in shape or
not; the flowers of geranium are regular, while those of violets
are irregular. Regular flowers are also spoken of as ACTINO-
MORPHIC or RADIAL, and irregular flowers as ZYGOMORPHIC. The
latter are also spoken of as DORSIVENTRAL. Dorsiventral flowers
either arise as such, as in some of the Leguminosae (Fig. 231),
or they may arise as radial flowers and become dorsiventral dur-
ing the course of development, as in willow herb (Fig. 224).

In some flowers the floral envelopes are wanting, and the
flowers are said to be NAKED, as in the willows and grasses.

ANTHOTAXY. — The study of the arrangement of flowers on
the stem is known as anthotaxy. The flowering axis may bear
only a single terminal flower, as in Tulipa; or the flowers may
occur singly in the axils of the leaves, as in Viola canadensis.
When, on the other hand, the flowers are borne upon a branch
shoot, the internodes of which are more or less condensed, and
the leaves smaller and of a more simple structure than the
foliaceous leaves, the whole shoot is known as an INFLORESCENCE,
and the leaves are called BRACTS. The flower thus represents a
single unbranched shoot, while the inflorescence represents a
branched or ramified shoot.

The so-called bracts, besides being generally smaller than the
leaves proper, are mostly sessile ; they may, however, be green, or
membranaceous, or they may exhibit a bright coloration, as in
Monarda.

The stalk of the individual flower is called a PEDICEL, and
may be naked, or bear one or two small bracts, which are called
FORE-LEAVES or PROPHYLLA. In the monocotyledons there is
usually only one fore-leaf, which turns its back to the mother-axis
and is frequently two-nerved and two-keeled. In the dicotyledons
there are generally two fore-leaves, which are placed to the right
and left of the flower, as in the violets.

The position of the floral leaves (the sepals, the petals and
those of the perianth) depends upon the arrangement of the
fore-leaves, so that in most of the monocotyledons, where there

394 A TEXT-BOOK OF BOTANY.

is one mediane prophyllon, the first leaf of the perianth is placed
on the front, while the two succeeding leaves of the perianth
occupy a position of 120° from this (Fig. 254). When, on the
other hand, as in the dicotyledons with pentamerous flowers,
two fore-leaves are developed, the first floral leaf (sepal) is
situated obliquely above the last fore-leaf, usually on the frontal
part of the flower; the second sepal is directly behind the first
or diagonally opposite to it, the remaining three leaves (sepals)
occurring in a spiral of two-fifths (Fig. 280). Several deviations
from this type occur, as in Lobelia (Fig. 224), Polygala, etc.

Two types of inflorescence are distinguished: (i) The IN-
DEFINITE, in which the flowers open or develop in acropetalous
or centripetal succession, and (2) the DEFINITE, in which the
flowers open in basipetalous or centrifugal succession. The in-
definite type of inflorescence is seldom terminated by an ex-
panded flower, and two classes of this type are distinguished :
(a) Those in which the flowers are pedicelled, as in the raceme
(Fig. 267) and umbel (Fig. 344), and (b) in which the flowers
are sessile, as in the spike (Fig. 230) and head (Fig. 228).

The RACEME is a long inflorescence with pedicelled flowers,
which are frequently subtended by bracts (Figs. 224, 225, and
293)- The CORYMB is a modified raceme in which the pedicels
of the basal flowers are much longer than those of the apical,
and thus the inflorescence looks like an umbel. In the milkweed
the flowers have pedicels of the same length which arise from the
apex of the shoot or peduncle, and this form of inflorescence is
known as an UMBEL. In the Umbelliferae a flower cluster or
umbellet takes the place of the individual flowers of the umbel,
and is known as a COMPOUND UMBEL (Figs. 346-348).

The SPIKE is also generally a long inflorescence, the flowers
being sessile (Fig. 230, illus. 3), the secondary spikes in grasses
being known as SPIKELETS. The SPADIX is a form of spike,
which is readily distinguished by the fleshy stem, in which the
flowers are frequently deeply imbedded, and which is frequently
surrounded by a large bract, the so-called SPATHE, as in Arissema.
The CATKIN is a kind of spike with small, often imperfect flowers,
which falls off as a whole, as in the staminate catkins of the
oak. The catkins are mostly decompound, and in some species

MORPHOLOGY OF HIGHER PLANTS. 395

of Populus the single flowers are pedicelled, and hence are actually
racemose rather than spicate inflorescences.

In the head and the umbel the main inflorescential axis is
exceedingly short and the innermost flowers are often destitute
of bracts, in contrast with the external, which are frequently
provided with bracts that are of quite considerable size. Sterile
bracts also occur in these two types, and are called involucral
leaves, as in Cornus florida, where they are white or pink. There
is also a difference in sex of the outer and inner flowers. While
the head occurs as typical inflorescence in the Compositse, it also
exists in some of the L^mbelli ferae.

The flowers of the Composite? are borne on a common torus,
known as the disk, which is subtended by one or more circles of
bracts, these constituting an INVOLUCRE. The flowers are of two,
kinds, and they receive different names because of their form and,
position. Those situated near the margin of the disk are known
as RAY-FLOWERS, and because they possess more or less strap-
shaped corollas are also known as LIGULATE FLOWERS. Those
occupying the central portion of the disk are known as DISK-
FLOWERS, or as TUBULAR FLOWERS because of the tubular shape of
the corolla. Most of the Composite possess both ligulate and
tubular flowers, as Arnica, Matricaria (Fig. 228), the common
daisy, etc. But some of the members of the family have only
ligulate flowers, as chicory and dandelion, and a relatively few
have only tubular flowers.

Two types of definite inflorescence are distinguished : ( I )
the DIBRACHIOUS (bifurcate) CYME in which the inflorescence
represents a series of very regularly arranged lateral axes, one
on each side of the terminal or median flower, as in the Caryo-
phyllaceae; and (2) the MONOBRACHIOUS (simple) CYME, of which
there are several modifications, but common to all of them is the
development of only one lateral branch to each terminal flower.
In the SCORPIOID cyme the lateral axes are arranged alternately
to the right and left, while in the HELICOID cyme the lateral axes
are all on the same side of the main axis, as in Hypericum. The
so-called flower cluster is a cymose inflorescence of either the
definite or indefinite type in which the flowers are almost sessile
or very short pedicelled, as in Chenopodium, Juncus, etc. Some-

396

A TEXT-BOOK OF BOTANY.

times the inflorescence may be decompound or complex, as in
several Composite, where the heads may be arranged in cymes
or racemes; or, as in the Graminese, where the spikelets, which

FIG. 228. Matricaria: A, longitudinal section of head showing torus (a), involucre
(b), ray florets (c) and disk florets (d). B, head with the florets removed, showing the long
conical torus and the involucre (H). C, tubular floret showing the ovary (f) with glandular
hairs (D1) and the embryo (S), which develops after fertilization; style (g) and bifid stigma
(N), the surface of which is covered with hairs; n, nectaries; b, corolla tube with narrow
lobes (a); stamens showing filaments (st), united anthers (A) and apex of connective (sp).
D, ligulate floret showing ovary (F), and bifid stigma (N); tube of corolla (R) and the
upper ligulate portion (Z). — After Meyer.

are spikes, may be arranged in panicles, i.e., branched racemes;
or finally, as in Cryptotaenia (Umbelli ferae), where the umbels
are arranged in cymes.

MORPHOLOGY OF HIGHER PLANTS. 397

Pollination and Fertilization. — Fertilization represents the
final stage in the work of the flower as a whole, and has already
been defined as the union of the egg-cell and a male nucleus.
Pollination may be considered to include the transferral of the
pollen grains from the anther to stigma and their subsequent
germination thereon, this latter process resulting in the produc-
tion of the male nuclei. Pollination thus represents but one series
of changes or processes which precede fertilization, for, while the
pollen grain is going through the various stages in development
which lead to the formation of the male nuclei, a series of com-
plex changes are going on in the embryo-sac leading to the develop-
ment of the egg-cell.

Our special interest in pollination arises from the fact that the
pollen grains are not retained in the pollen sacs and are dependent
upon various agencies for transferral to the stigma. This is a
matter of great biological significance, for it is claimed that many
of the special characters of flowers have a direct relation to
pollination.

The various ways in which the anthers open for the discharge
of the pollen when it is ripe have already been considered (Fig.
221), but it may be added that the manner in which this is done
usually appears to have a relation to the manner in which the
pollen is to be carried to the stigma. In order that pollination
may be effected, the stigma must be ripe or mature, when it is
said to be receptive. It then usually secretes a sticky, sugary
liquid which causes the pollen grains to adhere to the stigmatic
surface (Fig. 83), and which at the same time serves as a nutrient
to them. Usually the pollen grains begin to germinate in a short
time after reaching the stigma, which is made evident by the pro-
trusion of the pollen tubes. The stigma seems also to have the
power of selection, for in many cases the pollen does not germi-
nate as readily on the stigma of the same flower as on that of
another flower, provided it be of the same or a nearly related
species.

When a flower possesses both stamens and pistils, — that is, is
bisexual or hermaphrodite, — and its pollen germinates upon its
own stigma, the process is known as close or SELF-POLLINATION,
and if fertilization follows, this is known as SELF-FERTILIZATION.

398 A TEXT-BOOK OF BOTANY.

While most hermaphrodite flowers are self-pollinated, there are
some that are not, and this is brought about in several ways :
(i) As already pointed out, the pollen may germinate better on
the stigma of another flower than on the stigma of the same
flower. (2) The anthers and pistils of the same flower may mature
at different times, and this is one of the commonest ways of
preventing self-pollination. Usually in such cases the stamens
mature first. The common plantain (Plantago) furnishes an
example of the maturing of the stigma before the anther. The
flowers of this plant are arranged in spikes (Fig. 230, illus. 3
and 4) which belong to the indefinite class, and hence the lower
flowers on the spike expand first. As stated, the pistil of each,
flower matures first, and after it withers the stamens protrude an
discharge their pollen. It is evident that the flowers can not b
self-pollinated, nor is it likely that one flower will be pollinated
|by another of the same spike. (3) The stamens and pistils of the
same flower may vary in length, as in Polygonum (Fig. 230, illus.
i and 2) and Lythrum (Fig. 230, illus. 5), or stand in such other
relation to each other that self-pollination will not be effected,
as in some of the irregular or zygomorphic flowers, like those of
Orchids. In these several cases the pollen grains either fall upon
or are carried by various agents to the stigmas of other flowers,
and this is known as CROSS-POLLINATION, and the fertilization
which follows as CROSS-FERTILIZATION.

Cross-fertilization is an advantage to the species, for usually
the seeds which result from this process give rise to plants which
are more vigorous and otherwise superior to those which result
from self-fertilization. In some cases, in order to insure the pro-
duction of fruit, hand-pollination is practised, as by the growers
of vanilla and some other tropical plants of economic importance.

In the case of unisexual flowers, or those in which the stamens
and pistils are in separate flowers, there is, of course, no chance
for self-pollination. Here, as in the case of cross-pollinated her-
maphrodite flowers,, pollination may be more or less close or it
may be remote, as between flowers of the same cluster or inflores-
cence, between flowers of different clusters or inflorescences on
the same plant, or between flowers on different plants.

In buckwheat (Fig. 230, illus. i and 2) and partridge berry

MORPHOLOGY OF HIGHER PLANTS.

399

(Mitchella repens) two kinds of flowers are produced, viz.: (a)
one with short styles and long filaments, and another (b) with
long styles and short filaments, and thus the flowers appear to be
especially adapted for insect cross-pollination and are called
DIMORPHIC. In still other cases one species gives rise to three
kinds of flowers, depending upon the difference in the relative
lengths of the styles and filaments, as in the purple loosestrife
(Lythrum calcaratum), and such flowers are called TRIMORPHIC.
The external agents which are instrumental in carrying pollen
from one flower to another and thereby promoting cross-pollina-

FIG. 229. Visitation of flowers by insects showing how they gather the pollen and
assist in cross-pollination, the one on the left being Lilium Martagon visited by a hawk
moth, showing that while the proboscis is removing honey from the nectary the under
side of the body is becoming covered with pollen; at the right Cydonia vulgaris, the common
quince, visited by a bee, whose legs are becoming covered with pollen. — After Dodel-Port.

tion are the wind, water currents, insects, small animals and birds,
such as humming-birds, which are, even in temperate regions,
to be observed visiting the garden nasturtium.

In many of the early-flowering trees, as well as pines, Indian
corn, etc., the flowers are devoid of showy, attractive features,
but produce large quantities of pollen which is more or less dry
and powdery and carried by the wind to other flowers. Flowers
which are wind-pollinated are classed as ANEMOPHILOUS, and it is
estimated that about one-tenth of all the flower-producing plants
belong to this class.

Plants which are pollinated by the aid of water currents are

400

A TEXT-BOOK OF BOTANY.

FIG. 230. Manner of cross-pollination in some hermaphrodite flowers, i, 2,
Flowers of buckwheat, showing long style and short filaments in i , and short styles and
long filaments in 2: a, .anthers; st, stigmas; n, nectaries. 3, Spike of plantain showing
maturing of stamens below and pistils above. 4, Dissected flower of plantain: b, bract;
c, calyx; p, corolla tube; s, stamens; t, protruding withered style. 5, Flowers of Purple
willow-herb (Lythrum Salicaria) , one side of the perianth removed from each. A is long-
styled, B, medium-styled, and C, short-styled. The direction of the arrows and dotted lines
indicates the best methods of crossing. — i, 2, 5, adapted from Warming.

MORPHOLOGY OF HIGHER PLANTS. 401

FIG. 231. A, flowering and fruiting plant of peanut (Arachis hypogcea). After fertiliza-
tion the carpophore (or stalk between calyx and ovary) grows in length, sometimes 4 to 8
cm., and curves downward penetrating the soil (el), after which the fruit develops. B.
longitudinal section through the papilionaceous (bilateral) flower; C. longitudinal section
through the pod (peanut). — After Taubert.

known as HYDROPHILOUS, and under this head are included those
plants which live under the water and those that produce flowers
at or near the surface of the water.

Those plants which depend upon the visitation of insects for
26

402 A TEXT-BOOK OF BOTANY.

the transferral of the pollen in cross-pollination are called ENTO-
MOPHILOUS (Fig. 229). They frequently possess bright, highly
colored flowers, and it is considered that these serve as an attrac-
tion to the insects which visit them. The insects are, however,
probably more attracted by the odor and food products which
they obtain, such as the nectar. The nectar is secreted by glands
known as nectaries, which are variously located ; frequently
they are on the torus, either between the ovary and stamens
(Fig. 78) or between the stamens and petals. Sometimes the
stamen is modified to a nectar-secreting spur, as in the violets.
In aconite the nectary is developed from one of the posterior
petals (Fig. 223, E). In seeking the nectar the pollen of the ripe
anther may fall upon or adhere to the insects and thus be carried
from one flower to another (Fig. 230).

HONEY is a product formed through transformation of the
plant nectar by honey bees. The nectar is supposed to be acted
upon by certain salivary secretions of the bee and changed into a
fruit-sugar, the so-called honey, consisting of a mixture of dex-
trose and levulose. The nectar of buckwheat and clover (partic-
ularly white clover) is the principal source of the commercial
article. The nectar of some plants is poisonous and may furnish a
poisonous honey (see discussion under Ericaceae).

THE INNER STRUCTURE OF THE FLOWER.

The inner structure of the flower bears a close resemblance
to that of the stem and leaf. The BRACTS in almost all particulars
are like the foliage leaf of the same plant, and the FLOWER STALK
closely resembles the foliage stem. The CALYX, while resembling
the foliage leaf, usually contains calcium oxalate in greater amount,
and the chlorenchyma consists wholly of rather loose chlorophyll
parenchyma ; the outer or under epidermis contains the stomata,
and if hairs are present, they also arise from this surface; the
fibrovascular bundles are generally simple in structure, although
in some cases, as in lavender, sclerenchymatous fibers are strongly
developed.

In the COROLLA the epidermal cells are generally more or less
centrifugally developed, forming prominent papillae (Fig. 232,
A, B), which give the petals a velvety or satiny appearance, as in

MORPHOLOGY OF HIGHER PLANTS.

403

the rose ; glandular and non-glandular hairs are also developed
which are peculiar to the corollas of irregular flowers, as in La-
vandula vera and Viola tricolor (Figs. 124, 149-155, 232);
stomata are comparatively few in number. The epidermal cells

FIG. 232. Inner morphology of the flower as illustrated in Viola tricolor. A, epider-
mal cells from the outer surface of the spurred petal showing papillae; B, epidermal cells
from the under surface of the petals, some of the cells showing centripetal thickenings, the
two without thickenings indicating the epidermal mucilage-cells; C, epidermal cells from
the under surface of the petals showing a zigzag outline and short centripetal thickenings;
D, surface view of the mesophyll of the petals; E, corkscrew-like hair from the innet sur-
face of the spurred corolla near the throat; F, a hair from the edge of an anther; G, epider-
mal cells of the anthers; H, surface view of the mesophyll cells from the spurred stamen
showing collenchymatous thickening; I, surface view of cells of endothecium; K, pollen
grain viewed from the side; L, pollen grain examined in water; M, pollen grain observed
in chloral solution.

are but slightly cutinized, and in surface view are strongly undu-
late and appear striate owing to the papillose development (Figs.
232 and 235). The chlorenchyma is made up of rather loose,
branching parenchyma cells ( Fig. 232, D ) , with large, intercellular
spaces. The cells are free from chloroplastids, may contajn

404 A TEXT-BOOK OF BOTANY.

chromoplastids, or, like the epidermal cells, a colored sap ; in some
instances, as in the buttercups, starch grains are also found in
the mesophyll. Calcium oxalate crystals are usually present, and
milk vessels ate sometimes found, as in the Papaveraceae.

The FILAMENT and connective possess a central fibrovascular
bundle, around which are arranged comparatively small paren-
chyma cells and among which secretion cells are sometimes scat-
tered, as in Tilia. The pollen sacs consist of but two layers of
cells — an outer layer called the "exothecium," which resembles
the epidermis of the corolla, and an inner layer called the " endo-
thecium," the cells of which are contractile and peculiarly thick-
ened, this feature being rather characteristic for certain species
(Fig. 232, /). Lining the pollen sacs during their development,

FIG. 233. Several forms ot pollen grains: A, crocus; B, arnica, with three thin places
in the wall through one of which the pollen tube may protrude; C, lavender showing six
thin places in the wall.

there is a layer of cells, called the " tapetal cells " ; but these are
usually sooner or later absorbed.

The POLLEN GRAINS vary greatly in number, as well as in
size and shape. They are usually more or less ellipsoidal, but
may be spherical, as in Crocus (Fig. 233, A) ; more or less three-
sided, as in the Composite and in cloves ; four- or five-sided, as in
Viola tricolor (Fig. 232, K, L, M), and in some cases, as in the
Pinaceae, they may be winged. In addition to protoplasm and
one or more nuclei, pollen grains contain considerable oil and
starch. The outer or enclosing membrane (Fig. 233) consists of
two parts : an inner one, known as the " intine," and consisting of
cellulose, and an outer, known as the " exine," apparently con-
sisting chiefly of cutin; in some cases the exine also contains an
oil which is colorless, as in Salvia, or yellowish, as in lavender,
and in some instances it may contain a viscid substance, causing

MORPHOLOGY OF HIGHER PLANTS.

405

the pollen grains to adhere, as in CEnothera. The grains may be
smooth or variously sculptured ; in most instances the exine is
unevenly developed, leaving thin places through which the pollen
tubes protrude in germination; these give the appearance of

FIG. 234. A, Crocus (Spanish saffron) showing two spherical pollen grains, a fragment
of stigma with papillae, and fragment of an anther; B, Calendula showing 3 spinose pollen
grains and fragment of corolla, the cells of which contain oil-like globules; C, Carthamus
(so-called American saffron) showing 2 slightly spinose pollen grains and a fragment of
the corolla with brown laticif erous vessels and numerous unicellular hairs. — After Weakley.

grooves when the grains are dry, and the number of grooves is
characteristic for different species; in most of the Composite
they are three in number ; in the Labiatae there are six, while in
Crocus they are wanting (Fig. 234).

The epidermal cells of the STIGMA are quite characteristic.

4o6 A TEXT-BOOK OF BOTANY.

The cells of the epidermis, or so-called " stigma-epithel," may be
palisade-like, forming a more or less wart-like mass, as in the
viscous stigmas of the Umbelliferae, or the outer walls may be
modified to rather broad papillae, as in matricaria and arnica,
or they may be developed into hair-like processes, as in crocus.
The pollen tubes either enter, the style through an open canal,
as in the violets, or they penetrate into the conducting tissues
of the style, either through the papillae, as in malva, or through
the middle lamella of two neighboring papillae, as in Atropa
Belladonna.

The important tissue of the STYLE is the conducting tissue ; in
styles which are hollow it forms the lining of the canal, the cells
resembling those of the stigma-epithel ; in styles that are solid
the conducting tissue occupies the central axis and consists of
somewhat elongated cells, the walls of which are generally thick,
frequently strongly refractive and possess the property of swell-
ing, being furthermore separated by large intercellular spaces.
Surrounding the conducting tissue are thin-walled parenchyma
cells, in which the fibrovascular bundles are distributed, the num-
ber of groups of the latter corresponding to the number of carpels
that compose the gynaecium. There may also occur secretion cells,
containing mucilage, as in malva, or oil and resin, as in matri-
caria. Occasionally, the parenchyma is replaced either in part
or entirely by mechanical cells, and the epidermal cells may be
modified to hairs.

The tissues of the OVARY are, as a rule, in a very rudimentary
condition ; in fact, so rudimentary that it is difficult to distinguish
the ovaries of two flowers that develop into quite different fruits.
In some instances it is said that, notwithstanding the subsequent
changes, each cell of the fruit is already indicated in the ovary.
The ovary possesses an outer and an inner epidermis; the outer
is provided with stomata and. may also possess hairs; the inner
may also have stomata and after fertilization may develop secre-
tion hairs, as in the orange. Between the epidermal layers occur
thin-walled parenchyma cells which contain leucoplastids and
chloroplastids, and in which the fibrovascular bundles are dis-
tributed, these being usually simple, or complex, as in the pea.
The number of fibrovascular bundles is more or less dependent

MORPHOLOGY OF HIGHER PLANTS.

407

FIG. 235. Inner morphology of flower of Primula officinalis: A, papillae on stigma
of flower with long styles; B, papillae from stigma of flower with short styles; C, sec-
tion through petals showing papillose epidermal layers and branching cells of mesophyll ;
D, section through corolla tube showing glandular hairs on epidermis; E, surface view of
epidermal cells of petals, those of the corolla tube being elongated and shown on the left,
while those of the outspreading petals are polygonal and striated from the folds in the
papillae; F, a pollen grain. — Redrawn by Haase from drawing of Hans Kramer in Ber.
d. d. pharm. Ges., 1907, p. 352.

4o8 A TEXT-BOOK OF BOTANY.

upon the number of carpels that make up the gynaecium; as a
rule, there is a strong fibrovascular bundle which corresponds to
the mid-vein of each carpel.

The PLACENTA is a development from the inner epidermis. It
is traversed by a fibrovascular bundle from which branches are
given off to the individual ovules ; it may have a conducting tissue
similar to that found in the style, and in some cases the epidermis
of the stalk of the ovule may be developed to a stigma-epithel.

The OVULE not only possesses a distinct form as already given,
but the internal structure, by reason of the changes associated with
fertilization, is more or less characteristic for certain species and
genera. It has an epidermal layer, the outer walls of which are
more or less cutinized, and it consists for the most part of paren-
chyma cells rich in protoplasm and food-materials ; in addition the
embryo-sac contains a number of nuclei. The stalk and raphe are
connected with the placenta by means of a fibrovascular bundle.

The NECTAR may be secreted by certain of the epidermal cells
of various parts of the flower; these may resemble the ordinary
epidermal cells or they may be modified to papillae, as in the
spurred stamens of the violets, or to hair-like processes, as in
malva. The cells which secrete nectar constitute the " nectar-
apparatus," and the walls are usually thin and more or less cutin-
ized. The nectar-apparatus is found more generally upon some
part of the stamen, but the sepals and petals are not infrequently
saccate or spurred, which adapts them for holding the nectar.

V. OUTER MORPHOLOGY OF THE FRUIT.

After the fertilization of the ovule or ovules, the parts of the
flower that play no further part either in protecting the seed or
aiding in its dispersal soon wither and are cast off ; in most flowers
the petals lose their color and, together with the stamens, style,
and stigma, wither and fall away shortly after fertilization. The
stigma may, however, persist, as in the poppy ; the style may like-
wise remain, as in Ranunculus, or even continue to grow or
lengthen, as in Taraxacum; in other cases the calyx persists, as
in orange and belladonna ; in still other cases the torus may be-
come fleshy and form a part of the fruit, as in pimenta and apple.
The fruit may consist, therefore, not only of the ripened pistil,

MORPHOLOGY OF HIGHER PLANTS. 409

FIG. 236. Different types of fruits. A, silique of mustard showing the separation of
the two valves leaving the seeds attached to the central axis; B, spinous capsule of Stra-
monium showing septifragal dehiscence into four valves, the capsule being strictly 2-
locular but apparently 4-locular owing to the formation of false dissepiments; C, s-valved
capsule of Geranium in which the carpels become detached from one another and roll up-
wards remaining attached to the beak-like compound style; D, capsule of Hyoscyamus
showing transverse dehiscence by means of a lid (i) and the two loculi containing numerous
small seeds; E, fruit of strawberry showing fleshy torus and numerous embedded akenes;
F, silicula of shepherd's-purse showing seeds attached to central axis and longitudinal
dehiscence of the valves which remain attached below; G, fruit of rose, so-called rose "hip,"
the akenes being enclosed by the hollow oval torus which shows remains of calyx at the
apex; H, multiple fruit of mulberry composed of small drupes, the pulpy portion of each
consisting of the fleshy perianth. — Adapted from Warming.

but also of other parts of the flower and torus which persist or
develop with it.

4io

A TEXT-BOOK OF BOTANY.

The wall of the fruit is called the PERICARP, and, like the leaf,
it consists of three distinct layers, viz. : ( i ) the outer layer corre-
sponding to the outer epidermis of the ovary is called the EPICARP
or EXOCARP; (2) the inner layer corresponding to the inner
epidermis of the ovary is called the ENDOCARP, or, from the fact
that it is sometimes hard and stone-like, it is called the PUTAMEN,
as in the prune; and (3) the middle layer situated between the
epicarp and endocarp is called the MESOCARP ; and from the fact
that it is sometimes succulent or fleshy, as in the prune, it is also
called the SARCOCARP.

There are a number of distinctive and descriptive names applied
to fruits. Some of the more imoortant are as follows :

FIG. 237. A, transverse section of colocynth showing seeds (s) borne on parietal
placentas; B, transverse section of fruit of Ricinus communis showing septicidal dehis-
cence of capsule, the seeds (s) being borne on axial placentas; C, transverse section of card-
amom showing loculicidal dehiscence, the seeds (s), as in B, being borne on axial placentas.

An Achene is a non-fleshy, or so-called dry, unilocular and
one-seeded, indehiscent fruit, in which the pericarp is more or less
firm, and may or may not be united with the seed. Achenes may
be inferior, as in the Composite (Fig. 227), where they develop
from inferior ovaries, being frequently surmounted by the pappus
or calyx; or half inferior, as in the rose (Fig. 236, G), where they
develop from half inferior ovaries ; or superior, as in the buttercup
(Fig. 223, D).

A Berry is a fleshy, indehiscent fruit, the seeds of which
are embedded in the sarcocarp; berries are superior when they
develop free from the torus, as in belladonna (Fig. 239), capsi-
cum, grape, etc., and inferior when the torus forms a part of
the fruit, as in banana, cranberry (Fig. 244), and gooseberry
(Fig. 245).

MORPHOLOGY OF HIGHER PLANTS.

411

A Capsule is a dry, dehiscent fruit, consisting of two or more
united carpels. Dehiscence in capsules may occur in five different
ways: In the castor-bean (Fig. 237, B) the carpels separate from
each other along the walls or septa (dissepiments), the seeds being
discharged along the ventral suture of the separated carpels, and
this mode of dehiscence is called SEPTICIDAL. In mustard (Fig.

FIG. 238. Capsules of poppy (Papaver somniferum) , whole and in transverse and
longitudinal sections, showing dissepiments and remains of radiate stigmas at the apex,
which are porous and through which the seeds are discharged, i, French capsules; 2,
German capsules.

236, A ) the dissepiments remain intact and dehiscence occurs along
the margin of the capsule, and is therefore called MARGINICIDAL ;
but as the partial carpels (or valves, as they are termed) separate
from the walls or septa, the dehiscence is also known as SEPTI-
FRAGAL. In cardamom (Fig. 237, Q the septa as well as valves
are united, and at maturity the latter separate and dehisce at points
in the margin corresponding to the mid-vein of the carpel, and

412

A TEXT-BOOK OF BOTANY.

this form of dehiscence is known as LOCULTCTDAL. In poppy
capsules (Fig. 238) there are a few openings beneath the united

PIG. 239. Several forms of fruits: A, branch of Apocynum androscemifolium showing
numerous flowers and a single fruit with 2 long, slender follicles. Comparative size of follicles
in A. androscemifolium (B), and A. cannabinum (C). Branch of Solatium carolinense
showing a number of small superior berries (D). Pyxis of Scopolia carniolica showing
slightly lobed calyx and upper portion of fruit (E). Pyxis in Hyoscyamus niger showing
calyx lobes extending much above the fruit (F). Berry of Atropa Belladonna cut trans-
versely and showing the numerous small seeds (G). Young spinose capsule of Datura
Stramonium (H).

stigmas through which the seeds are expelled, and this form of
dehiscence is known as POROUS. In hyoscyamus (Fig. 236, D) a

MORPHOLOGY OF HIGHER PLANTS.

413

portion of the capsule comes off from the remainder like a lid,
and this form of dehiscence being circular or transverse to the

1st
II ^L* ^^ qst

Alb

FIG. 240. The fruit of the cocoanut palm (Cocos nueifera): I, ripe cocoanut fruit
showing lower part of axis forming the stem (S), upper end of axil with scars of male flowers
(A), epicarp (Ep), mesocarp (M) with fibers, endocarp or hard shell (E), portion of testa
adhering to endosperm (T), endosperm surrounding cavity of nut (Alb) and germinating
eye (K); II, longitudinal-radial section of endocarp through the stone cells and edge of
bundle showing transversely elongated and isodiametric stone cells (qst), longitudinally
elongated stone cells (ist), thick-walled porous cells (f), pitted tracheae (g) and spiral
tracheae (sp); III, longitudinal section of a large (mesocarp) fiber showing stegmata (ste),
silicious body (Si), bast fibers (f), tracheids with small pits (t), tracheids with large pits
(tO, spiral tracheae (sp), reticulated tracheae (r), scalariform tracheae (sc), sieve tube (s)
and cambiform cells (c and c')- — After Winton.

sutures of the carpel, it is called CIRCUMCISSILE. A capsule of
this kind is known as a Pyxis or Pyxidium.

A TEXT-BOOK OF BOTANY.

— mes

st

VI

FIG. 241. Fruit of the huckleberry (Gaylussacia resinosa): I, fruit seen from above;
II, transverse section of fruit; III, stone; IV, transverse section of stone showing endocarp
(End), testa (S), endosperm (E) and embryo (em); V, transverse section of outer portion
of the pericarp showing epicarp (epi), hypoderm (hy), mesocarp (mes) and stone cells (st) ;
VI, transverse section of endocarp and seed showing large isodiametric stone cells (End),
narrow longitudinally extended fibers (If), testa (S), hyaline layer or nucellus (N) and
endosperm (E). — After Winton.

MORPHOLOGY OF HIGHER PLANTS.

R,

415

FlG. 242. Cultivated strawberry (Fragaria chiloensis): I, Compound fruit showing
fleshy receptacle bearing the achenes in deep depressions; II, isolated achene; III, achene
showing style (Sty), stigma (Sti) and connecting bundle (B); IV, achene in transverse
section, pericarp (F), testa (S).raphe (R), endosperm (E) and embryo (Em); V, receptacle
in surface view showing epidermis (Ep), with hair (h), and stoma (sto); hypoderm (hy)
and sphero-crystals (k) ; VI, achene in transverse section showing pericarp (F) consisting
of epicarp (epi), mesocarp (mes), spiral vessels (sp), crystal layer (k) , outer endocarp (If)
with longitudinally extended fibers and inner endocarp (qf) with transversely extended
fibers; testa (S) consisting of epidermis (ep) with reticulated cells, elongated brown cells
(br), hyaline layer or nucellus (N) and endosperm (E) consisting of a single layer of aleurone
grains; VII, style and stigma. — After Winton.

4i6

A TEXT-BOOK OF BOTANY.

FIG. 243. Red Raspberry (Rubus Idaus): I, Compound fruit consisting of a number
of drupelets crowded together on the top and sides of the receptacle; II, transverse section
of a drupelet showing"epicarp (epi), hypoderm (Hy), mesocarp (Mes), outer endocarp (F),
inner endocarp (F'), testa (S), raphe (R), endosperm (E), and embryo (Em); III, stone
including endocarp and seed; IV, stone somewhat magnified; V, style and stigma; VI,
surface section of epicarp showing straight hair (h'), sinuous hairs (h) and stoma (sto);
VII, transverse section of endocarp and seed showing endocarp (End) consisting of longi-
tudinally extended fibers (If), transversely extended fibers (qf), testa (S) consisting of
epidermis (ep), parenchyma or nutritive layer (p), and inner epidermis (iep); hyaline
layer or nucellus (N), endosperm (E) with aleurone grains (k). — After Winton.

MORPHOLOGY OF HIGHER PLANTS.

A Caryopsis, or Grain, is an indehiscent, non-fleshy fruit
possessing a thin pericarp, which is closely adherent to the thin
seed-coats, as in wheat, corn, and other Gramineae (Figs.
255,256).

i— <•)

— -E

VII

FIG. 244. The fruit of the cultivated cranberry (Vaccinium macrocarpon): I, berry
seen from above; II, transverse section of berry; III, single seed;. IV, transverse section
of seed showing outer epidermis (S), inner layer of seed-coat (S'), raphe (R), endosperm (E)
and embryo (Em); V, surface section of endocarp with stoma; VI, seed in transverse sec-
tion showing epidermis of seed-coat (ep) with sclerenchymatized and mucilaginous layers,
inner layer of seed-coat (m) and endosperm (E); VII, surface section of epidermis of seed-
coat. — After Winton.

A Cremocarp is a dry, indehiscent fruit which consists of
two inferior achenes, known as MERICARPS; these are separated
from each other by means of a stalk known as a CARPOPHORE.
27

418

A TEXT-BOOK OF BOTANY.

FIG. 245. The fruit of the American Gooseberry (Ribes oxyacanthoides}: I, whole
fruit; II, transverse section of fruit with seeds; III, seeds deprived of gelatinous coat;
IV, floral parts; V, surface section of epidermis from margin of calyx with hairs; VI, surface
section of epidermis from throat of calyx with hair. — After Winton.

This fruit is characteristic of the Umbellifera. (Consult Volume
II for pharmacognosy of medicinal umbelliferous fruits.)

A Drupe is a fleshy, indehiscent fruit with a more or less
succulent and well-developed sarcocarp and an indurated endo-

MORPHOLOGY OF HIGHER PLANTS. 419

carp. Drupes are superior when they are free from the torus, as
in prune ; inferior when the torus forms a part of the fruit, as
in pimenta. Drupes are also spoken of as " dry " when the sarco-
carp is less succulent, as in Rhus glabra, or when they are col-
lected unripe, as in pepper, pimenta, and cubeb. The fruits of the
raspberry and blackberry consist of a collection of little drupes,
the whole being known as an ET^RIO. In the blackberry the
drupelets cohere with the fleshy torus, while in the raspberry the
drupelets cohere with one another, forming a cap which is sepa-
rable from the cone-shaped torus. If the drupelets of the rasp-
berry are examined closely it will be found (Fig. 243) that each
has from 4 to 7 facets on the sides formed by the pressure of the
adjoining drupelets. These facets are usually slightly convex or
concave. Tschierske states that the individuals cling together,
first, because of the closely-fitting adjoining facets, the slightly
convex surface of one fitting into a corresponding concave surface
of another; and, second, because of the interlocking of the sinuous
hairs.

A Follicle is a dry, dehiscent fruit which consists of one
or more separate carpels, the dehiscence being usually along the
ventral suture (Fig. 239) ; in Delphinium the carpels are single ; in
aconite from 3 to 5, and in star-anise (Illicium) from 7 to 8; in
magnolia the carpels are numerous, forming a kind of succulent
cone, and dehisce along the dorsal suture.

A Galbalus is a berry-like fruit, formed by the coalescence
of fleshy, open scales, as in juniper (Fig. 75).

Hesperidium. — The fleshy, indehiscent, superior fruit of citrus,
as lemon and orange, is known as a hesperidium. The pericarp
is more or less coriaceous, and from the inner walls secretion hairs
develop, which contain sugar and an acid cell-sap, these consti-
tuting the fleshy portion in which the seeds are embedded.

A Legume is an elongated, monocarpellary, usually dry,
dehiscent fruit, in which dehiscence takes place along both sutures,
the carpel thus dividing into two halves, or valves, as in the garden
pea (Pisum) and other members of the Leguminosse (Fig. 231).
In some cases legumes are jointed or articulated and indehiscent,
breaking up at maturity into a number of parts which are dis-
persed in much the same manner as samara-fruits, as in Meibomia.

420 A TEXT-BOOK OF BOTANY.

Legumes may be not only indehiscent but fleshy, as in Cassia
fistula.

A Nut is an achene-like fruit, the pericarp o'f which is more
or less indurated. Nuts are sometimes subtended (as in acorns)
or enclosed (as in chestnuts) by a kind of involucre, forming
what is technically known as a cupule ; and a fruit consisting of a
nut and cupule is known as a GLANS. The achene-like fruit of
the Labiatae is spoken of as a Nutlet.

A Pepo is an inferior berry, in which the placentas have
become developed into succulent layers, as in the watermelon,
cucumber, and colocynth.

A Pod is a general term used to designate all dry, dehiscent,
apocarpous, or syncarpous fruits, as capsules, follicles, and
legumes.

A Pome is an indehiscent, half-inferior, fleshy, syncarpous
fruit, as in the apple. The carpels constitute the core, and the
fleshy part is developed from the torus.

A Samara is a winged, achene-like fruit. The winged ap-
pendage may be at the apex, as in white ash, or around the edge, as
in elm. Two samaras may be united into one fruit, which is called
a " double samara," as in maple.

A Silique is a narrow, elongated, 2-valved capsule which is
separated by the formation of a false dissepiment into 2 locules, as
in the Cruciferse (Fig. 236, A).

A Sorosis is a fleshy fruit resulting from the aggregation
of the carpels of several flowers, as in mulberry (Fig. 236, //)
and pineapple.

A Strobile or cone is a scaly fruit, at the base of each scale
of which there is either a seed, as in the Pinacece, or an achene-like
body, as in hop.

A Syconium consists of a succulent hollow torus, which en-
closes a number of achene-like bodies, as in the fig (Ficus).

An Utricle is an inferior achene with a thin and loose pericarp,
as in Chenopodium.

Classification of Fruits. — More or less artificial classifications
of fruits have been made. They may be grouped either according
to structure or according to their manner of protection or dispersal,
the following classification being based on the structure :

MORPHOLOGY OF HIGHER PLANTS.

421

From a number of flowers.

From a single
flower

A. With a compound pistil.

a. Indehlscent

Dry....

Fleshy ,

b. Dehiscent ] Dry

Strobile or Cone

Sorosis

Syconium
(Achene

Caryopsis

Cremocarp

Nut

Samara

Utricle

Berry

Drupe

Etaerio

Hesperidium

Pepo

Pome
f Capsule
1 Follicle

B, With a simple pistil

a. Indehiscent . . . \ Fleshy . . \ Drupe

b. Dehiscent \ Dry

[Follicle
I Legume

THE INNER STRUCTURE OF FRUITS.

The inner structure of fruits is quite variable and it is difficult
to treat of this in a general way. In the simplest fruits there are
three distinct layers, as in the capsule of cardamom, in which
there is an outer epidermis of isodiametric or polygonal cells,
an inner epidermis of more or less obliterated and elongated cells,
between which is a thin-walled parenchyma traversed by a number
of fib ro vascular bundles.

In some cases the other epidermis contains numerous stomata,
as in poppy capsules, or is developed into hairs and other out-
growths or appendages, as in anise, arnica, sumach (Fig. 148),
and raspberry (Fig. 243).

The inner epidermis may also contain stomata, as in the poppy,
or be developed into hairs, as in vanilla and orange, or more or less
obliterated, as in achene-like fruits, or modified to sclerenchy-
matous elements, as in drupes.

422

A TEXT-BOOK OF BOTANY.

The middle layer, which is composed of parenchyma, may con-
tain protoplasm, starch, sugars, calcium oxalate, coloring princi-
ples, alkaloids and other principles, and it may also have oil-secre-
tion cells, as in cubeb and pepper, or oil-secretion canals, as in
^orange (Fig. 121) and the fruits of the Umbelliferae, in the latter

FIG. 246. Rhamnus cathartica. A, cross-section through wall of the pericarp. E, epi-
carp; F, sarcocarp; H, endocarp; e, epidermis; o, calcium oxalate in cells of hypodermis; p,
parenchyma; h, secretion cells containing a substance which is insoluble in alcohol or chloral
solutions, soluble in solutions of potassium hydroxide, and colored reddish brown or green-
ish with ferric chloride solutions; c, calcium oxalate cells of endocarp; w, sclerotic cells; f,
stereome cells. B, cross-section of entire fruit, showing one seed; E, F. H, g, f, w, as in A;
S, seed-coat; S1, outer wall of seed-coat; End, endosperm; c, cotyledons; g, vascular bundle.
C, cross-section of a seed: S1, S2, S3, different layers of the seed-coat; R, vascular bundle of
raphe; t, position of vessels of mestome strand; g, mestome strand; Rf, cleft in which raphe
is situated; End, endosperm; C cotyledons; Sv, cells with thick walls;Sp,parenchymatous
cells. — After Meyer.

of which they are known as vittse (see Volume II) ; milk vessels
sometimes occur, as in poppy; a collenchymatous layer is some-
times developed beneath the epidermis, as in capsicum; in some
cases sclerenchymatous cells may be present, as in pimenta and
cubeb (Fig. 135) ; and in still other instances the entire pericarp
may be made up of stone cells, as in the nuts.

MORPHOLOGY OF HIGHER PLANTS.

VI. THE OUTER MORPHOLOGY OF THE SEED.

423

The seed may be defined as the fertilized and developed ovule.
The seeds of different fruits vary in number as well as in size

FIG. 247. Transverse (I) and longitudinal (II) sections of oat grain (Avena saliva):
i, 2, cells of pericarp; 3, seed-coat; 4, remains of perisperm; 5, cells containing gluten;
7, endosperm cells containing considerable proteins and some starch; 6, endosperm cells
With polygonal compound starch grains; 8, fibrovascular bundle of the pericarp. — After Harz.

and shape. In form they correspond to the ovules ; in size they
vary from about 0.600 mm., as in lobelia, belladonna, etc., to 10 or
15 centimeters in diameter, as in the cocoanut palm. Seldom are

424

A TEXT-BOOK OF BOTANY.

all of the ovules of the pistil fertilized, hence the number of seeds
is usually less than the number of ovules.

Structure of Seed. — After the fertilization of the egg-cell
certain changes take place in the embryo-sac: At one end the
developing embryo is attached to the wall by a short stalk or
suspensor (Fig. 82) ; the nuclei, lying in a mass of cytoplasm

A"

FIG. 248. Citrullus Colocynthis. A, seed: a, in longitudinal section, and b, surface view;
S, deep clefts or fissures; m, micropyle; g, hilum; w, radicle; c, cotyledons. B, parenchyma
cells of ripe fruit showing simple pores, the walls are colored blue with chlor-zinc-iodide.
C, longitudinal section of wall of pericarp of ripe fruit showing e, epidermis; p, parenchyma;
Sc, sclerotic cells which gradually pass into a thick-walled parenchyma consisting of small
cells (p'); g. spiral vessels; P, isodiametric, porous parenchyma cells, containing air and of
which the fruit for the most part consists. D, cross-section of seed-coat showing, G, an
outer layer which is more or less easily separable from the rest of the seed and the walls of
which are somewhat mucilaginous; E, epidermis of palisade-like cells; Sc, sclerotic cells; PI,
a layer of tabular cells with undulate walls; T, a layer of small somewhat branching cells,
the walls of which are not strongly thickened and either porous or reticulate; P, several
layers of parenchyma and the collapsed epidermis; Pe, perisperm; En, endosperm. E,
tangential section of tabular sclerotic cells of seed-coat shown in PI in Fig. D. — After Meyer.

around the wall of the embryo-sac, divide and re-divide; the large
vacuole in the center becomes filled with a watery or milky fluid,
and later the nuclei, with portions of the cytoplasm, may be
enclosed by a cellulose wall and become permanent cells, in which
the embryo is embedded. Likewise in the nucellus, changes are
also taking place ; the cells are found to be dividing, and storing
starch, oil, aleurone, and other food materials, like the cells of the

MORPHOLOGY OF HIGHER PLANTS. 425

embryo-sac. The cells in which these materials are stored are
known as reserve cells, and in the nucellus they constitute the
PERISPERM, while those formed in the embryo-sac make up the
ENDOSPERM. Usually the endosperm of seeds is prominently de-
veloped, while the perisperm occurs as a thin layer ; in some seeds,
however, the endosperm and perisperm are both well developed.
In some instances the embryo may not fill the embryo-sac, as in
cocoanut, and sometimes, as in the almond, both of the reserve
layers are consumed in the development of the embryo, when the
seed is said to be without endosperm (Fig. 248).

The perisperm and endosperm are sometimes spoken of to-
gether as the albumen of the seed, but as the cells comprised in
these layers contain not only protoplasmic contents and aleurone
grains, but starches, oils, and other substances, the term is mis-
leading. On this basis, seeds containing either endosperm or
perisperm, or both, have been designated as albuminous, but on
.account of these layers containing larger proportions of other,
(substances than proteins it would be better to speak of them as

RESERVE LAYERS (FigS. 247, 250).

While these changes in the nucellus and embryo-sac have been
going on there have been equally great changes in the coats of
the ovules, which develop into the seed-coats. In the seed the
two coats are generally readily distinguishable. The inner, as
in Ricinus, Pepo, etc., is thin, light in color, of a delicate structure,
and is known as the TEGMEN ; the outer is more or less thickened,
of a darker color and firmer in structure, and is known as the
TESTA. In some instances the perisperm, or both perisperm and
endosperm, may be reduced to a thin layer when it is considered
to form a part of the seed-coat, as in mustard. In other cases the
two coats are so closely united that they are not easily distin-
guished, as in stramonium.

The terms used in describing the kinds of ovules (atropous,
anatropous, campylotropous, etc.) are retained in the description
of the seeds ; and in describing the different parts of the seed some
of the terms which were applied to the ovule are also retained, as
chalaza and raphe ; the seed when ripe usually becomes detached
from its stalk, and the resulting scar is called the HILUM ; that
part of the seed corresponding to the foramen of the ovule is
more or less closed and is known as the MICROPYLE; the embryo

426

A TEXT-BOOK OF DOT ANY.

develops in such a way that the tip of the young root always
points in the direction of the micropyle.

In the fully developed embryo three distinct parts may be dif-
ferentiated (Fig. 161) : (i) The COTYLEDONS; (2) the part below
the cotyledons, known as the HYPOCOTYL, the apical portion of
which constitutes the young root or RADICLE;-^) the part above

B

pe

FIG. 249. Forms of embryo and distribution of endosperm in various seeds and
fruits. A, Ricinus seed: car, caruncle; m, micropyle; e, embryo. B, superior drupe of
Piper: per, pericarp; e, endosperm; p, perisperm. C, spinach fruit and D, corn cockle seed
(Agrostemma Githago): per, pericarp; t, seed-coat; h, hilum; p, perisperm; e, endosperm
c, curved embryo. — A, C, D, after Harz; B, after Baillon.

the cotyledons, known as the EPICOTYL, the apex of which con-
sists of a more or less developed bud spoken of as the PLUMULE.
The position of the embryo (Figs. 249, 250) in the seed varies
somewhat : in most seeds it lies in the center, as in strophanthus
and linum; it may, however, be excentral, as in colchicum and
nutmeg. The cotyledons are usually situated above the hypocotyl,
but in the Cruci ferae, either their edges lie against the hypocotyl,
as in the mustards, when they are said to be ACCUMBENT or con-

MORPHOLOGY OF HIGHER PLANTS. 427

duplicate, or they lie so that the back of one is against the hypo-
cotyl, as in Lepidium, which position is known as INCUMBENT.

Externally, the seed-coats vary considerably ; they may be
nearly smooth, as in ricinus ; finely pitted, as in the mustards ;
prominently reticulate, as in staphisagria ; hairy, as in cotton,
strophanthus, and apocynum (Fig. 251 ) ; or winged, as in the seeds
of the catalpa. There are also a number of other appendages, these
having received special names: the wart-like development at the
micropyle or hilum of some seeds, as in castor-bean and violet, is
known as the CARUNCLE; in the case of sanguinaria, a wing-like
development extends along the raphe, and this is known as the
STROPHIOLE ; in some cases the appendage may completely envelop
the seed, when it is termed an ARILLUS ; when such an envelope
arises at or near the micropyle of the seed, as the mace in nutmeg,
it is known as a " false arillus," or ARILLODE.

Seed Dispersal. — Seeds and fruits are distributed in various
ways, and so are often found growing in localities far from their
native habitat. In some instances seeds are adapted for distribu-
tion by the wind, being winged, as in Paulownia, Catalpa, and
Bignonia, or plumed and awned, as in Strophanthus Kombe,
Asclepias, and Apocynum (Fig. 251 ). As examples of fruits hav-
ing special parts which aid in their distribution may be mentioned
the achene of Taraxacum which is provided with a pappus (Fig.
227), the bladder-like pericarp of Chenopodium, and the winged
fruit or samara of maple. The hooked or barbed appendages on
some fruits serve to attach them to animals, and thus they may be
widely distributed, as in the burdock and Spanish needles (Bidens
bipinnata). In still other cases fruits may be carried long distances
by water currents, or even by ocean currents, as those of thej
Double-cocoanut palm (Lodo'icea sechellarum) , which while
native of the Seychelles Islands is now found on many of the
islands in the Pacific and Indian Oceans. It may also be mentioned
in this connection that a number of fruits, as the garden balsam,
castor-oil plant, violets (pansy, etc.), Wistaria, etc., are elastically
dehiscent and discharge the seeds with considerable force.

THE INNER STRUCTURE OF THE SEED.

The SEED-COAT usually consists of from two to six layers of
cells: (i) an outer layer or so-called epidermis, (2) a layer of

428

A TEXT-BOOK OF BOTANY.

sclerenchymatous cells or stone cells, (3) a pigment layer, (4, 5)
one or two rows of parenchymatous cells, (6) a row of more or
less obliterated parenchyma cells.

The EPIDERMAL CELLS vary considerably in different species

D

FIG. 250. A. — Longitudinal section through anatropous seed of Knum: R, raphe; SC,
seed-coat; M, hilum; H, micropyle; EN, endosperm; C, cotyledon; HY, hypocotyl. B. —
Longitudinal section through stramonium seed: SC, seed-coat; H, micropyle; M, hilum;
EN, endosperm; E, curved embryo. C. — Transverse section through endosperm of nux
vomica showing thick-walled parenchyma, the cells containing oil and protoplasm. D. —
Transverse section through endosperm of seed of Ricinus comrmtnis, one cell filled with
aleurone grains, each with a crystalloid and globoid, and another in which the aleurone
grains have been dissolved, the cytoplasm and nucleus remaining.

both as regards the form of the cells and the composition of the
walls (Fig. 136). The cells may be more or less isodiametric in
cross-section, as in cardamom (see Vol. II) ; elliptical, as in almond
(Fig. 136, D) ; palisade-like, as in Abrus precatorius, or more or

MORPHOLOGY OF HIGHER PLANTS. 429

less irregular, as in Delphinium. While the outer and side walls
are usually thickened, in hyoscyamus (Fig. 251), it is the inner
and side walls which are thickened, the outer wall remaining thin.
The outer wall may be in part modified to mucilage, as in mustard
and flaxseed (Fig. 119) ; or to non-glandular hairs which consist
either of cellulose, as in cotton (Fig. 139), or lignocellulose, as
in nux vomica (Fig. 119).

The PERISPERM and ENDOSPERM (Fig. 249) consist chiefly of
parenchyma cells, which contain, besides protoplasm, starch, as
A B

FIG. 251. Seeds: A, of Hyoscyamus muticus with epidermal cells having wavy, thick-
ened walls, those at the edge are seen in section and snowing that the outer wall is not
thickened. B, of Lobelia inflata showing reticulate seed-coat composed of uniformly thick-
ened and strongly lignified cells. C, of Apocynum cannabinum with numerous long i-celled
hyaline hairs.

in physostigma ; oil, as in flaxseed and cottonseed ; aleurone grains,
as in ricinus (Fig. 250); glucosides, as in almond; alkaloids,
as in stramonium. The walls are usually thin, but may in some
instances be considerably thickened, as in coffee, colchicum, and
nux vomica (Fig. 135).

The embryo consists chiefly of parenchyma cells with a few
fibrovascular bundles: the cotyledons may be thin and leaf-like,
as in ricinus and nux vomica, or thick and fleshy, as in almond
and cola, or partly developed, as in strophanthus ; the hypocotyl
is usually small, but in the Umbelliferae it is as large as the
cotyledons.

CHAPTER IV.

BOTANICAL 'NOMENCLATURE.

LET the student consult the various manuals on Botany and
even some of the larger authoritative works and he will be imme-
diately impressed that there is more or less confusion concerning
the names of certain plants. For instance, in looking up the
botanical origin of the False Solomon's Seal, one author will give
it as Smilacina racemosa, while another writer will use the name
of Vagnera racemosa. Again, if the student desires to use the
correct family name he will be confused both as to the correct
spelling of the name as well as the name of the family itself, the
Grass Family being given as Graminacese or Gramineae ; the
Leguminosse may be divided into the Mimosacese, Csesalpinacese
and Papilionaceae. At first thought it might seem that this incon-
sistency is peculiar to botanical science, but as a matter of fact
we find the same difficulties in the language of other sciences.
This confusion is due to the fact that up until now there has not
been an international agreement or even one of a national character
regarding the rules to be observed in botanical nomenclature.

" For many decades it has been almost universally felt that
botanical nomenclature should rest in a general way on the prin-
ciple of priority of publication, or, in other words, that the name
of a plant was the first one assigned to it. Nearly all botanists of
note have readily assented to this general idea, but great difficulties
have arisen regarding the precise limitations which should be
imposed upon the principle. Thus, botanists of past generations,
including such great leaders as the De Candolles, Bentham, the
Hookers, Gray, von Martins, Eichler, Baillon, and others, have
followed the principle of priority, yet they have made frequent
exceptions based on considerations of taste and convenience as well
as practicality."

" With the expansion of the subject the difficulty of agreement
on these exceptions has increased, and some recent writers have
been disposed at times to criticise rather harshly the earlier bot-
anists for making any exceptions whatever. It should be noticed,
430

BOTANICAL NOMENCLATURE. 431

however, that even the more strenuous of these reformers them-
selves admit certain exceptions. They have found it necessary, for
instance, to fix initial dates, and to rule out certain names as too
vague in their definition or too uncouth in their form to be
accepted."

" Ideas as to the best mode of establishing rules or reaching
a general agreement regarding the necessary exceptions to the bald
principle of priority have differed widely and given rise to lively
controversy. To some it has seemed best to advise an ideal system
and then, without much reference to the wishes or convenience
of their colleagues, to apply it in local publication. To the vast
majority, however, it has been clear that the subject was a broad
one, involving much mutual sacrifice before the now divergent
usages at different botanical centers could be brought into har-
mony. The question is also an international one, requiring the
botanists of different nations to attain a common agreement. For
some years there was a growing desire for an international meet-
ing of representative botanists who should give the matter of
nomenclature careful consideration and come, if possible, to
some agreement on the fundamental rules to be followed. This
feeling took definite form in the year 1900, when preliminary
sessions of such a gathering were held in connection with the
Paris Congress of Botanists. At this meeting a bureau was
formed for the organization of an International Botanical- Con-
gress to be held at Vienna in June, 1905." This congress convened
in Vienna and was attended by between five and six hundred bota-
nists, representing the leading botanical institutions of the world.
They framed international rules which should be used in the
botanical nomenclature of vascular plants, and a complete list
of these will be found in Rhodora, the journal of the New
England Botanical Club, for March, 1907. A few of the general
considerations and leading principles will be mentioned, however,
in order that the student may have some understanding of the
subject.

According to the Vienna Congress, the prescriptions, which
should govern the system of botanical nomenclature, are divided
into (i) principles, (2) rules, and (3) recommendations.

Among the principles that should be adhered to is that scientific

432 A TEXT-BOOK OF BOTANY.

names are to be in Latin for all groups. When taken from another
language, a Latin termination is given them, except in cases
sanctioned by custom. If translated into a modern language, it is
desirable that they should preserve as great a resemblance as
possible to the original Latin names.

Among the rules to be followed in designating the nature and
the subordination of the several groups, the following were
adopted :

Every individual plant belongs to a species (species), every
species to a genus (genus), every genus to a family (familia),
every family to an order (ordo), every order to a class (classis),
every class to a division (divisio). In a number of species varie-
ties and forms are also distinguished. In some cultivated species
there are unlimited modifications. The crossing of one species
with another species gives rise to a hybrid.

Regarding the point of nomenclature and limitation of principle
of priority, it was agreed at the congress that botanical nomen-
clature should begin with the Species Plantarum of Linnaeus,
ed. i (1753), for all groups of vascular plants. It was further
agreed to associate genera, the names of which appear in this
work, with descriptions given of them by him in his Genera Plan-
tarum, ed. 5 (1754). However, to avoid disadvantageous changes
in the nomenclature of genera by the strict application of the rules
of nomenclature, and especially of the principle of priority in
starting from 1753, the rules provide a list of names which must
be retained in all cases. These names are by preference those
which have come into general use in the fifty years following their
publication, or which have been used in monographs and important
floristic works up to the year 1890.

Among the recommendations, the following suggestions were
made in regard to the nomenclature of divisions, classes, families,
genera, and species :

i. Names of divisions and subdivisions, of classes and sub-
classes are taken from one of their characters. They are expressed
by words of Greek or Latin origin, some similarity of form and
termination being given to those that designate groups of the same
nature, as Angiospermae, Gymnospermae ; Monocotyledoneae, Di-
cotyledonese ; Coni ferae; Pteridophyta. Among Cryptogams old

BOTANICAL NOMENCLATURE. 433

family names such as Fungi, Lichenes, Algae, may be used for
names of groups above the rank of family.

2. Orders are designated preferably by the name of one of their
principal families, with the ending -ales, e.g., Polygonales from
Polygonaceae. Suborders are designated in a similar manner,
with the ending -ineae, e.g., Malvineae from Malvaceae. But other
terminations may be retained for these names, provided that they
do not lead to confusion or error.

3. The names of families are designated by the name of one of
their genera or ancient generic names with the ending -aceae, e.g.,
Rosacese from Rosa, etc. The following names, owing to long
usage, are an exception to the rule : Palmae, Gramineae, Cruciferae,
Leguminosae, Gutti ferae, Umbelli ferae, Labiatae, and Compositae.

4. The names of genera should be substantives (or adjectives
used as substantives) in the singular number and written with a
capital letter, which may be compared with our own family names.
These names may be taken from any source whatever and may
even be composed in an absolutely arbitrary manner, as Rosa,
Convolvulus, Liquidambar, Impatiens, and Manihot.

5. The names of all species, even those that singly constitute
a genus, are designated by the name of the genus to which they be-
long, followed by a name (or epithet) termed specific, usually of
the nature of an adjective (forming a combination of two names, a
binomial, or binary name). The specific name should, in general,
give so-me indication of the appearance, the characters, the origin,
the history, or the properties of the species. If taken from the
name of a person, it usually recalls the name of the one who discov-
ered o-r described it, or was in some way concerned with it. Specific
names begin with a small letter, except those which are taken from
names of persons or those which are taken from generic names.

The student should endeavor to fix in mind the general prin-
ciples concerning botanical nomenclature and should devote special
attention to the generic and specific names and the rules which
govern their formation. In addition he should familiarize himself
with the meaning of the names, as this will enable him to memorize
and spell them correctly. The following is a partial list of some of
the principal generic and specific names, giving as far as possible
the origin of the names and their significance:
28

434 A TEXT-BOOK OF BOTANY.

Abelmoschus. Muskmallow. From Arab. Abu-l-misk, father of musk;

producing musk.

Abies. Fir. The classical Latin name.
Abrotanum. Southernwood. Gr. afipdrovov ', from aflpoToc ? sacred to the

gods, immortal ; probably in allusion to the odor.
Abrus. Indian licorice. From Gr. a/fydf, graceful; in allusion to the

flowers.

Absinthium. Wormwood. The ancient Greek name.
Abyssinicus-a-um. Pertaining to Abyssinia.
Acacia. The ancient Greek name of an Egyptian species. From a*i?, a

point ; referring to the thorns.
Acer. Maple. The classical Latin name.
Acer, acris, acre. Sharp, pungent. From root ak, to be sharp.
Achillea. Yarrow, Milfoil. Named for the Greek warrior Achilles, who

is said to have discovered the virtues of the plant.
Aconitum. Monkshood, Wolfsbane. The ancient Greek name.
Acorus. Sweet flag. The ancient classical name.
Actaea. Baneberry, Cohosh. Ancient Greek name of the elder.
Acuminatus-a-um. Acuminate, tapering. Lat. acumino, to make pointed.
Acutifolius-a-um. Having sharp-pointed leaves. Lat. acutus, sharp, -f-

folium, a leaf.
Adiantum. Maidenhair. The ancient name. From Gr. «, priv., + diaivu, to

wet, hence unwetted, incapable of being wet.
Adonis. Pheasant's eye. A plant fabled to have sprung from the blood

of the beautiful Adonis.
Advena. Yellow pond lily. From Lat. advena, strange, foreign. (Of

doubtful application.)
Aegle. Bengal quince. Name of a nymph in Greek mythology. Perhaps

from aty/b?, brightness, splendor.

^sculus. Horsechestnut. The Latin name of an oak or some other mast-
bearing tree.
y£stivalis-e. Pertaining to the summer. The classical Latin word is

(ustivalis.

Agaricus. Mushrooms. Gr. ayapmov. Lat. agarici(m, a tree fungus.
Agave. American aloe. Gr. dyaw?, noble, illustrious. Appropriately

applied to Agave americana, the century plant.
Agrimonia. Probably a corruption from argemone. According to others,

it is derived from Gr. dypdf, field, + JJLOVO^^ alone.
Agropyron. Wheat grass. From Gr. dypdr, field, + nvpos, wheat ; alluding

to the fact that it grows wild in wheat fields.

Agrostemma. Corn cockle. From Gr. dypdf, field, + <n-f////a, a crown.
Ailanthus. Tree of heaven. Said to be from aylanto, the name of the

tree in the Moluccas, in allusion to its height.
Ajuga. Bugle weed. From Gr. a priv., + (.vyov (Lat. iugum), a yoke.

From the fact that the lower lip of the corolla has a single, con-
spicuous middle lobe.

BOTANICAL NOMENCLATURE. 435

Albizzia. Name derived from the Albizzi, a noble family of Italy, one
of whom is said to have introduced this genus into European culti-
vation.

Albus-a-um. White.

Alchemilla. Lady's mantle. From the Arabic name alkemelyeh; in refer-
ence to the silky pubescence of some species.

Aletris. Star grass, Colic-root. From Gr. dAer/Mf, a female slave who
grinds ; in allusion to the mealy appearance of the blossoms.

Algae. Plural of alga, sea-weed ; probably a shortened form of alliga, from
ad, to, + ligo, to bind.

Allium. Onion, Garlic. The ancient Latin name for garlic; perhaps con-
nected with Lat. oleo, to emit a smell.

Alnus. Alder. The ancient Latin name.

Aloe. The ancient Greek name.

Alsine. Chickweed. Greek name of a plant.

Alstonia. Dita. Named for Dr. Charles Alston, botanist, of Edinburgh
(1683-1/60).

Althaea. Marshmallow. Hollyhock. The classical name. From Gr.
aMaivu, to heal, cure ; in allusion to the medicinal properties of the
plant.

Alyssum. Greek name of a plant believed to check hydrophobia ; from a
priv., + ^vooa, raging madness. Or a plant used to check hiccup ;
from a priv., + Mfa, to have the hiccup.

Amaranthus. Amaranth. From Gr.d^apairof, unfading; because the bracts
are dry and persistent.

Amarus-a-um. Bitter.

Amaryllis. Belladonna lily. Greek name of a shepherdess.

Ambrosia. Ragweed. The Greek and Latin name of several plants, as
well as of the food of the immortals.

Ambrosioides. Gr. a/ufipoaia -f- o- eitif/G, like, resembling ambrosia.

Americanus-a-um. Belonging to America.

Ammania. Named for Paul Ammann, a German botanist prior to
Linnaeus.

Ammoniacum. A resinous gum which exudes from a tree that grew near
the temple of Jupiter Ammon. The Greek name.

Amomum. Cardamom. Greek name of an Indian spice plant.

Amorpha. False indigo. From Gr. d/zopc&of, deformed, a, priv., + /«y)0#,
form ; in allusion to the absence of four of the petals.

Amygdalus. Almond. Peach. Ancient Greek name. From a^va™, to
tear, rend ; in allusion to the furrows on the endocarp.

Amylum. Starch. The Greek name. From a priv., + /^Xr;, a mill ; re-
ferring to its fineness, which makes it unnecessary for it to be ground.

Anacardium. Cashew. From Gr. avd, similar to, + Kapdia, heart. The
fruit of the plant is thought to resemble the heart of a bird.

Anacyclus. Pellitory. An abbreviation for ananthocyclus. From Gr. a
priv., -j- a/^of, flower, -f- KVK^OC, circle ; in allusion to the pistillate
or infertile rays. Meaning rather vague.

43*6 A TEXT-BOOK OF BOTANY.

Anagallis. Pimpernel. The ancient Greek name. Probably from dvd}

again, -f Ayd\\ut to delight in.

Anamirta. An Indian name synonymous with Menispermum.
Ananas. Pineapple. Sp. ananas, from the native American name.
Andira. Vouacapoua. From the vernacular Brazilian name.
Andropogon. Beard grass. From avfip, avdp6s, man, + TTW/WV, beard.
Anemone. Wind flower. The ancient Greek name. From dve//oc, wind.
Anethum. Dill. The ancient Greek name. Probably related to aviaov,

anise.
Angelica. From Gr. dyye/lof , messenger, angel ; in allusion to its cordial

and medicinal properties.

Angostura. Name of a city in Venezuela, whence angustura bark is im-
ported.
Angustifolius-a-um. Having narrow leaves. From Lat. angustus, narrow,

+ folium, leaf.

Anisum. Anise. Gr. avioov, avrjdov,

Annuus-a-um. Of one year's duration. Lat. annus, a year.
Anogra. Evening primrose. Name formed by transposition of letters

of Onagra, another name for this plant.
Anthelminticus-a-um. Worm-destroying. From Gr. avTt) against, -f-

etyivs, worm.

Anthemis. The ancient Greek name of chamomile.
Anthoxanthum. Sweet vernal grass. From Gr. avQos, flower, -f- t-avOoq^

yellow.

Aparine. Cleaverwort. The ancient Greek name of a plant.
Apocynum. Dogbane. Indian Hemp. The classical name. From cnr6f

from, + KVUV, dog.

Aquaticus-a-um. Growing in or by the water.
Aquifolium. Holly-leaved barberry. Ancient Latin name for the holly

tree or the scarlet holm.
Arabicus-a-um. Pertaining to Arabia.
Aralia. Derivation of name unknown.

Araroba. From East Indian name ar(ar)oba as applied to the bark.
Arctium. Burdock. From Gr. d^/crof, a. bear, or apKrtov, a plant.
Arctostaphylos. Bearberry. From Gr. d/o/crof , a bear, -j- ara^vA?/, a bunch

of grapes.

Areca. Betel-nut. Sp. and Port, areca, from East Indian vernacular name.
Argemone. Prickly poppy. The ancient Greek name for poppy. Accord-
ing to others, from apye/ua, a disease of the eye, for which the juice

of a plant so called by the Greeks was a supposed remedy.
Argithamnia. From Gr. apyvpoe, silver, + dd/uvo?, bush ; from the hoari-

ness of the original species.
Arissema. Indian turnip. From Gr. dp^, a kind of arum, -f- al/ta, blood ;

from the spotted leaves of some species.
Aristolochia. Birthwort. From Gr. apiaro?, best, + Ao^e/a, child-birth;

once thought to ease labor.

BOTANICAL NOMENCLATURE. 437

Arnica. From Gr. dpva/c/?, sheepskin, Lat. arnacis, a coat of sheepskin;

in reference to the hairy stem and leaves ; or, according to others,

from Gi'. irrapp.tK.6^^ Lat. ptarmicus, causing to sneeze.
Aromaticus-a-um. Aromatic, fragrant.
Artemisia. Wormwood, ancient Greek name of an herb. From the queen

Artemisia, wife of Mausolus.

Artemisiasfolius-a-um. Having leaves resembling those of Artemisia.
Artocarpus. Breadfruit. From Gr. <$prof, bread, + /CO/OTTO^, fruit.
Arum. Also Aron. The ancient Greek name apov.
Arundinaceus-a-um. Reed-like. From Lat. arundo, a reed.
Arvensis-e. Cultivated. From Lat. arva, an arable field.
Asagraea. From Asa Gray, the eminent American botanist.
Asarum. Hazelwort, Wild ginger. The ancient Greek name.
Asclepias. Milkweed, Silkweed. Named in honor of ^sculapius, the Latin

tutelary god of medicine.
Asimina. North American papaw. The Northern Algonkin corruption of

rassimina, in allusion to the shape of the fruit.
Asparagus. From the ancient Greek name aairapayos, asparagus.
Asperula. Woodruff weed. From Lat. asper, rough ; in allusion to some

scabrous species.
Aspidium. Shield fern. From Gr. dc-rruhov, a little shield ; from the shape

of the indusium.
Aspidosperma. From Gr. a<T7r/c, a shield, + atrlp/na, seed ; from the shape

of the seed.
Asplenium. Spleenwort. From Gr. a priv., + ffTrAr/u, the spleen ; because

of its supposed remedial properties.

Astragalus. Milk vetch. Gr. acrrpdyaAof, a leguminous plant.
Athamanticus-a-um. Of Athamas, a mountain in Thessaly ; with reference

to the habitat of the plant.
Atriplex. The ancient Latin name for orach; a corruption of the Greek

Atropa. Name from "ArpoTrof, one of the Greek Fates ; from a priv., +

rpoTn?, a turn ; hence unchangeable, inflexible.
Atropurpureus-a-um. From Lat. ater, dark, -f- purpureus, purple ; dark

purple.
Aurantium. Orange. From Lat. aurum, gold, referring to the color of the

fruit.

Australis-e. Southern. Lat. auster, the South wind.
Autumnalis-e. In the autumn ; referring to the time of blooming.
Avena. Oats. The classical Latin name.
Baccharis. Groundsel tree. The classical name of a shrub dedicated to

Bacchus.

Baccifer-a-um. Producing berries. Lat. bacca, a berry, + fero, to bear.
Ballota. Fetid horehound. The ancient Greek name.

438 A TEXT-BOOK OF BOTANY.

Balsamifer-a-um. Producing balsam. Lat. balsamum, balsam, + fero, to

bear.
Balsamum-ea. The classical name of the several trees yielding a balsam;

also in allusion to the balsamic oleo-resins obtained from the trees.
Baptisia. False indigo. From Gr. /3a7rr/£w, to dye.
Barbarea. Winter cress. Anciently called the Herb of St. Barbara.
Barosma. Buchu. From Gr. {3api>ef heavy, + 6o/«#, odor ; in reference to

its strong smell.
Belladonna. Ital. bella, beautiful, -j- donna, lady. It is said that Italian

ladies used the berries as a cosmetic and to dilate the pupil of the

eye, thus giving themselves a striking appearance.
Benedictus-a-um. Blessed, consecrated. Past participle of Lat. benedico,

to bless.

Benzoin. Wild allspice, Fever bush. Named from its odor, which resem-
bles that of benzoinum.
Benzoinum. A resinous substance from Styrax Benzoin, a tree of Sumatra,

Java. French benjoin, from Arabic luban-jawi, incense of Java.
Berberis. Barberry. Name derived from berberys, the Arabic name of

the fruit.

Beta. Beet. The ancient Latin name.
Betonica. Betony. The ancient Latin name (betonica, vcttonica) of wood

betony.

Betula. Birch. The ancient Latin name.
Betulinus-a-um. Pertaining to birch ; alluding to the fact that the leaves

resemble birch leaves.

Bidens. Bur marigold. From Lat. bidens, two-toothed.
Biennis-e. Of two years' duration. Lat. bis, twice, + annus, year.
Biflorus-a-um. Bearing two flowers, biflorate.
Bignonia. Named for the Abbe Jean 'Paul Bignon, court-librarian at Paris

and friend of Tournefort.
Bistorta. Adderswort. From bis, twice, + tortus (past participle of tor-

queo), twisted.
Boehmeria. False nettle. Named after G. R. Boehmer, German botanist

and professor at Wittenberg in the eighteenth century.
Botrychium. Moonwort. From Gr. /3<5r/ouf, a bunch of grapes; from the

appearance of the fructification.
Brachycerus-a-um. Having short horns. From Gr. /3pa^, short, -f-

/cfpaf, a horn.

Brasiliensis-e. Belonging to Brazil.

Brassica. Mustard. Turnip. The ancient Latin name for cabbage.
Brauneria. Purple cone-flower. Named for Jacob Brauner, German

botanist of the eighteenth century.
Bryonia. Bryony. The ancient Greek name. From ppvu, to swell, grow

luxuriantly.
Bursa. Capsella. Bursa is a late Latin word meaning purse.

BOTANICAL NOMENCLATURE. 439

Bursa-pastoris. Shepherd's purse.

Butneria. Spice bush.

Buxus. Boxwood. The ancient Latin name. Gr. TTI>£O?.

Cacao. Span, from Mex. kakahuatl; native name of the tree Theobroma

Cacao.

Cactus. The ancient Greek name of some thorny plant.
Caesalpinia. Sappan. Named for Andreas Csesalpinus, Italian botanist,

who died in 1603.
Cajuputi. Name of Malayan origin. From kayu, tree, -j- putih, white; in

reference to the appearance of the branches.
Calamus. Reed, cane. The classical word. So named because its scape is

reed-like.
Calendula. Marigold. Lat. calendar, calends, the first day of the month ;

so called because it flowers every month.
Californicus-a-um. Pertaining to California.
Calisaya. A name given to the bark of a tree of Peru by Spaniards and

Indians.
Calla. Water arum. Linnaeus derived calla from Gr. /cdAAam, a cock's

wattles, but compare Lat. calla, calsa, name of an unknown plant, and

Greek /caAdf, beautiful.
Calluna. Heather. From Gr. /caAluvw, to brush or sweep, brooms being

made from the twigs.

Calophyllum. Tacamahac. From Gr. AcaAdf, beautiful, + <f>vMov, a leaf.
Caltha. Marsh marigold. An ancient Latin name for the common mari-
gold.

Calumba. From kalumb, its native name in Mozambique.
Cambogia. From Cambodia, a French protectorate in Farther India.
Camelina. False flax. From Gr. xaC-a'1, dwarf, -}- Xfvov, flax.
Campechianus-a-um. Belonging to Campeachy.
Campestris-e. Growing in uncultivated fields.
Camphora. Gr. KaQovpd, from Arab, kafur, camphor.
Camptosorus. Walking leaf. From Gr. Aca/jTrrdf, flexible, -f- oup6$t sorus,

fruit dot.

Canadensis-e. Of or belonging to Canada.
Cannabinus-a-um. Pertaining to cannabis.
Cannabis. Hemp. The ancient Greek name.
Caoutchouc. Native South American name for the milky sap of several

plants. Also called India rubber.

Capillaceus-a-um. Hairy, very slender, like a hair. From Lat. capillus, hair.
Capillus-Veneris. Maidenhair. The Latin for hair of Venus.
Capsella. Shepherd's purse. Diminutive of capsa, a box.
Capsicum. Red pepper. From Lat. capsa, a box ; alluding to the shape of

the fruit. Or from Gr. /mTrrw, to bite, from its hot, pungent properties.
Cardamomum. The ancient classical name for the spice cardamom.
Carex. Sedge. The ancient Latin name.

440 A TEXT-BOOK OF BOTANY.

Carica. Papaw. The Latin name for dried fig, from Caria, in Asia Minor.

Carolinensis-e. i

Carolinianus-a-um. } Bel^ing to Carolina.

Carota. Carrot. The classical Latin word.

Carpinus. Hornbeam. The ancient Latin name.

Carum. Caraway. Gr. xdpov, Lat. careum. Probably from Caria, in Asia

Minor. •

Carvi or Carui. Probably an assimilated Latin genitive, as in Carui semina.
Caryophyllus. Cloves. From Gr. napvov, nut, + 0{vUov, a leaf ; referring

to the appearance of the flower buds.

Cascara Sagrada. Span. Cascara, bark, and sagrada, sacred ; holy bark.
Cascarilla. The bark of a Peruvian tree. Diminutive of cascara.
Cassia. Senna. An ancient Greek plant name Kaaia, probably from the

Hebrew getsiah, gatsa, to cut, peel off.
Castanea. The chestnut tree. The ancient Latin name, from a town in

Thessaly.

Catalpa. Indian bean. The aboriginal name.
Cataria. Catnip. From late Latin catus, a cat.
Catechu. East Indian name of extract from the acacia tree, applied natively

to all astringent extracts.
Cathartocarpus. Cleansing, purgative. From Gr. KaQaprLKog, cleansing, _|_

Kapn6c, fruit.
Caulophyllum. Blue cohosh. From Gr. /rau/ldf, a stem, + ^i/A/tov, a leaf ;

a stem-leaf.

Ceanothus. Red root. Gr. KedvuOo?, a kind of thistle.
Cedron. Cedron seed. From Gr. Ketipov, the fruit of the cedar.
Celastrus. Staff tree. The ancient Greek name of an evergreen tree.
Centaurea. Star thistle. Ancient Greek name of a plant. The plant of

the Centaurs.
Centifolius-a-um. Having a hundred leaves or petals. From Lat. centum,

hundred, + folium, a leaf.
Cephaelis. Ipecacuanha. From Gr. Ke0a/t#, head, + eUw, to collect, roll

up. The flowers are collected into a capitulum.
Cephalanthus. Buttonbush. From Gr. KetyaAJ], head, -f- av6o?t flower.

Flowers aggregated in spherical peduncled heads.
Ceratonia. St. John's bread. Greek name for the carrob or locust tree.

From K.ipaq , a horn ; alluding to the horn-shaped pods.
Cerealis-e. Pertaining to grain or agriculture. From Ceres, the Latin

goddess of agriculture.
Cetraria. Iceland moss. From Lat. ccetra, a shield ; in reference to the

shield-shaped apothecia.
Chamaenerion. Willow-herb. From Gr. ^a^at, on the ground, -f- vypiov,

rose-laurel.
Chamomilla. Earth apple. From Gr. xaftai, on tne earth, + ^ov, an

apple. From the apple-like odor of the flowers.

BOTANICAL NOMENCLATURE. 441

Chekan. The Chilian name of Eugenia Chekan.

Chelidonium. Celandine. From Gr. ^efoduv, a swallow, the flowers

appearing at the same time as the swallows.
Chelone. Turtlehead. Snakehead. From Gr. x£^vrf, a tortoise, the

corolla being shaped like the head of a reptile.
Chenopodium. Goosefoot. Pigweed. The ancient Greek name. From

XTJV, goose, + Trovf, foot.
Chimaphila. Pipsissewa. Bitter wintergreen. Love-in-winter. From Gr.

Xeifta, winter, + ^^«, to love ; in allusion to the several popular names.
Chionanthus. Fringe-tree. From Gr. ^6v, snow, + av6ofj flower ; in refer-
ence to the snow-white clusters of the flowers.
Chirata or Chirayita. From the Hindoo name chiraita.
Chondrodendron. From Gr. ^6v6pogf <a granule + 6ev6pov, a tree ; allud-
ing to the warty protuberances on the bark.
Chondrus. Sea moss. From Gr. xovdpoc, cartilage ; in reference to the

cartilaginous fronds.

Chrysanthemum. Gold-flower. The ancient Greek name.
Chrysarobinum. From Gr. xPva6a, gold, -f- araroba, a foreign name of

Goa powder.

Chrysophyllum. Star apple. From Gr. ^pwrrff, gold, + 0t>2/W, leaf.
Chrysosplenium. Golden saxifrage. From Gr. xpvats, gold, + trrr^i;, the

spleen. From its reputed medicinal properties.
Cichorium. Gr. /a'^opa, 'Succory, Chicory.

Cicuta. Water hemlock. The ancient Latin name of the hemlock.
Cimicifuga. Bugbane. From Lat. civnex, a bug, -f- fugo, to drive away.
Cinchona. Named for the countess of Chinchon, who brought the remedy

to Europe, when she returned with her husband, viceroy of Peru, in

1640.

Cinereus-a-um. Ash-colored. From Lat. cinis, ashes.
Cinnamomum. Cinnamon. The classical name.

Circaea. Enchanter's nightshade. Named after the enchantress Circe.
Cissampelos. From Gr. Ktaaoc;, ivy, + a/nre/lof, vine. From the fact that

it climbs like the ivy.

Citrullus. Melon. From Lat. citrus, the citron tree.
Citrus. Citron, Orange. The Latin name for the citron tree.
Clava-Herculis. Club of Hercules; from the appearance of the cone-like

cork-wings.

Clavatus-a-um. Club-like. From clava, a club.
Claviceps. Ergot. From Lat. clava, a club, + caput, head ; alluding to

the shape of the mycelium or sclerotium.
Clematis. Virgin's bower. Greek name of a creeping plant with long,

lithe branches. Probably clematis or periwinkle.
Clinopodium. Field thyme. Calamint. From Gr. KMvq, a -bed, + Trod?,

foot.
Clove. From Lat. clavus, a nail ; in allusion to the shape of the dried fruit.

442 A TEXT-BOOK OF BOTANY.

Cnicus. Blessed thistle. Latin name of the safflower, from the Gr.

Coca. Span, from native name of tree.

Cocculus. Diminutive of coccus, a berry.

Cochlearia. Scurvy grass. From Gr. Koxfadptov, a spoon ; with reference

to the shape of the leaves.

Coffea. Coffee. From Turk, qahveh, Arab, qahuah, name of a beverage.
Colchicum. Meadow saffron. From Gr. Ko^xk , Colchis, an ancient province

in Asia Minor, where this plant flourished.
Collinsonia. Horsebalm. Named in honor of Peter Collinson, English

botanist of the eighteenth century.

Colocynthis. From Gr. KofoitvvOq, a gourd or pumpkin.
Commelina. Day-flower. Named after the Dutch botanists J. and G.

Commelin, who lived in the seventeenth century.
Commiphora. Myrrh. From Gr. KO////<, gum, -f- Qopoc, bearing ; in allusion

to the exudation.
Communis-e. Common, general.

Conifer-a-um. From Lat. conns, a cone, -f fero, to bear, cone-bearing.
Conium. Poison hemlock. From KUVCIOV, the Greek word for hemlock.
Convallaria. Lily of the valley. From Lat. convallis, a valley.
Convolvulus. Bindweed. The ancient Latin name from convolve, to

entwine.
Copaiba. Span, and Port, from Brazil, cupauba, the native name of the

tree and its product.
Coptis. Goldthread. From Gr. KOTTTU, to cut; in allusion to the divided

leaves.

Corallorhiza. Coral root. From Gr. KopdMtov, coral, + j>%a, root.
Cordifolius-a-um. Heart-leafed. From Lat. cor, cordis, heart, + folium,

leaf.

Coriandrum. Coriander. The ancient Latin name, from Gr. Kopiavvov.
Coriarious-a-um. Pertaining to leather. Lat. corium, leather.
Cornus. Cornel. Dogwood. From Lat. cornu, a horn; alluding to the

hardness of the wood.
Coronilla. Axseed. Diminutive of Lat. corona, a crown; alluding to the

inflorescence.
Corylus. Hazelnut, Filbert. The classical name. Probably from Gr. Kopvf,

a helmet, from the helmet-like involucre.
Cotula. Mayweed. From Gr. nonfat, a hollow.
Cratsegus. Hawthorn. The Greek name of a kind of flowering thorn.

Perhaps derived from /cpdro?, strength.

Crenulatus-a-um. Notched. From crena, a notch, referring to the leaves.
Crispus-a-um. Curled, crisped.
Crocus. Saffron. The ancient Greek name. According to mythology, a

youth, Crocus, was changed into this flower.
Crotalaria. Rattle-box. From Gr. Kp6rafant, a rattle ; from the rattling of

the loose seeds in the pod.

BOTANICAL NOMENCLATURE. 443

Croton. From Gr. uporuv or Kpdruv, a tick, because the seed was thought

to resemble a tick. Also applied to the castor-oil seed.
Crucifer-a-um. Cross-bearing. From Lat. crux, cross, -\-fcro, to bear.

With reference to the form of the flowers.

Cruciger-a-um. Cross-bearing. From Lat. crux, cross, + gero, to bear.
Cubeba. Span, and Port, from Arab, kababat, native name of the plant.
Cucumis. Cucumber Melon. The ancient Latin name.
Cucurbita. Gourd, Squash. The ancient Latin name.
Cuminum. Cumin. The ancient Greek name.

Cunila. Dittany. Ancient Latin name for a plant, a species of orizanum.
Cupana. After Father Francis Cupani, Italian monk and botanist ; died

in 1710.

Cusparia. Angostura.

Cusso. Abyssinian name of the tree Hagenia Abyssinica.
Cyanus. Blue-bottle. The old Greek word for any dark-blue substance.
Cyminum. Cumin. Same as cuminum.
Cynoglossum. Hound's tongue. The classical name. From KVUV, dog, +

•yAuoaa, tongue ; from the shape and texture of the leaves.
Cyperus. Galingale. From Gr. idnreipof, a marsh plant.
Cypripedium. Lady's slipper. From Gr. Kv-npis, Venus, -f- 7mhAov, sandal.
Cytisus. Broom. An ancient classical name for a shrubby kind of clover,

perhaps Medicago arborea.
Damascenus-a-um. Pertaining to Damascus.
Daphne. Mezereum. Ancient Greek name of the bay-tree; from the

nymph, whom Apollo transformed into a laurel.
Datura. Jimson weed. Thorn apple. Name derived from Sans, dhattura,

Arab, tatura, tatula, the native name.
Daucus. Carrot. The ancient Greek name.
Decandrus-a-um. Having ten stamens. From Gr. MM, ten, -+- arfp,

avfipof, man.
Delphinium. Larkspur. Ancient Greek name, from dety/f (rktytv),

dolphin, in allusion to the shape of the flower.
Dentatus-a-um. Dentated, toothed. Lat. dens, tooth.
Desmodium. Tick Trefoil. From Gr. rfeo/zdf, a bond or chain; from the

connected joints of the pods.

Dianthus, Pink. Carnation. From Gr. A/df, oi Jupiter, + avtfof, flower.
Dicentra. From Gr. d/f, twice , -j- nevrpov, a spur.
Dictamnus. Dittany. The classical name. From Mt. Dicte, in Crete, on

which the plant grew luxuriantly.

Didymus-a-um. Twin, found in pairs. Gr. didvpoq, double.
Diervilla. Bush honeysuckle. Named for Dr. N. Dierville, who carried it

from Canada to Tournefort.
Digitalis. Foxglove. Lat. digitalis, of or belonging to the finger; alluding

to the finger-shaped corollas.

444 A TEXT-BOOK OF BOTANY.

Dioicus-a-um. Unisexual. The two sexes on different plants. Gr. di-t 61$,

twice, -f okof, a house.

Dioscorea. Yam. Dedicated to the Greek naturalist, Dioscorides.
Diospyros. Persimmon. From Gr. Ai6^f of Jupiter, -f irvp6gy grain.
Diphyllus-a-um. Having two leaves. Gr. di-t dig, twice, -{- <j>vMov, a leaf.
Dipsacus. Teasel. The classical name. Probably from diipa, thirst, be-
cause the united cup-shaped bases of the leaves of some species hold

water.

Dirca. Leatherwood. Moosewood. Name of uncertain origin.
Domesticus-a-um. Domestic, common.
Domingensis-e. Of Santo Domingo.

Dorema. Ammoniac plant. From Gr. duprjfia, a gift, benefit.
Dorstenia. Contrayerva. Named for T. Dorsten, German botanist, six-
teenth century.
Drosera. Sundew. From Gr. 6poaep6e} dewy. The glands of the leaves

exude drops of a clear glutinous fluid, which glitter like dewdrops.
Dryopteris. Greek name of a fern growing on oaks. From 6pv^t oak, +

Trrepif, a fern.

Dulcamara. Bittersweet. From Lat. dulds, sweet, + amarus, bitter.
Dulcis-e. Sweet.
Dysentericus-a-um. Pertaining to dysentery, dysenteric. Gr. 6va£VTepin6sy

afflicted with dysentery.

Ebenaceae. Ebony family. From Gr. Ifievoc, Lat. ebenus, ebony.
Ecballium. Squirting cucumber. From Gr. e/c? out of, -f- /M/l/lw, to throw.
Elasticus-a-um, Elastic, gummy. Probably formed from Gr.&aww, to drive.
Elaterium. Classic name for a medicine prepared from the juice of the

wild cucumber. From Gr. eTiavvu, to drive away.
Eleocharis. Spike rush. From Gr. £Aof, a marsh, + ^d/twf, grace ; being

marsh plants.

Elettaria. Cardamom. From elettari, native name of plant in Malabar.
Eleuteria. From Eleuthera, one of the Bahama Islands.
Epigaea. Ground laurel. Trailing arbutus. From Gr. eiri, upon, + yjj,

earth, in reference to its trailing growth.
Equisetaceae. Horsetail family. Ancient Latin name equis&tum (equi-

seta) , the plant horsetail.
Equisetum. Horsetail. Ancient Latin name. Derived from equus, horse,

-f- s&ta (seta), a bristle.
Erectus-a-um. Upright, elevated, lofty.
Ergota. Ergot. From French ergot, a spur.
Ericaceae. Heath family. From Gr. epeiK^9 heath, heather.
Erigeron. Fleabane. Ancient Greek name of a groundsel, probably

Senecio vulgaris. From jpit early, -f- -ytpov, old man, from the hoary

appearance of some vernal species.
Eriodictyon. From Gr. Ipiov, wool, + diicrvov, a net ; in allusion to the

woolly, net-veined leaves.

BOTANICAL NOMENCLATURE. 445

Erysimum. Treacle mustard. The Greek name of the hedge mustard;

from kpvuj to draw.
Erythroxylon. From Gr. ipvdpde, red, + f uA«w, wood ; referring to the

color of the trees or shrubs.
Esculentus-a-um. Good to eat, edible, esculent.
Eucalyptus. From Gr. ev} well, + /caAvTrrdf, covered ; from the conical

covering of the buds, which falls off at anthesis.
Eugenia. Clove-tree. Named in honor of Prince Eugene of Savoy.
Euonymus. Spindle tree. Ancient classical name for a shrub. From Gr.

et>, well, + dvo/ua, name.
Eupatorium. Thoroughwort. Dedicated to Eupator, king of Pontus,

who is said to have used one of the species in medicine.
Euphorbia. Spurge. Gr. ev^opjSiov, name of an African plant. Named

for Euphorbus, physician to king Juba.
Europseus-a-um. Belonging to Europe.
Excelsus-a-um. Lofty, high, surpassing.
Exogonium. From Gr. £gwf outside, -f- y6vo$, offspring; in allusion to the

exserted stamens and pistils.
Fagus. Beech. The ancient Latin name, from Gr. yayelv, to eat; in

allusion to the esculent nuts. Compare ^yof, a kind of oak bearing

esculent acorn.
Fagopyrum. Buckwheat. From Lat. fagus, beech, + Gr. irvpos, wheat;

from the resemblance of the grain to the beech-nut.

Farfara. Colt's-foot. Feminine form of farfarus, the ancient Latin name.
Farinosus-a-um. Pertaining to meal, mealy ; Lat. farina, meal.
Fastigiatus-a-um. High, pointed, tapering ; with reference to the shape

of the fruit. From Lat. fastigium, the top of a gable, summit.
Fertilis-e. Fruitful, fertile.
Ferula. Asafceticla. Latin name for the plant fennel-giant. From ferio,

to strike.

Ficus. The ancient Latin name for fig.
Filix-mas. Male fern. Lat. Filix, fern. Mas, male. In reference to its

asexual fructification.

Fistula. Reed, pipe, cane ; from the appearance of the long, slender fruit.
Fceniculum. Fennel. The classical Latin name. Diminutive of fcenum,

hay.

Fcetidus-a-um. Fetid, stinking. From Lat. factor, an offensive smell.
Fragaria. Strawberry. Lat. fraga, strawberries. From fragro, to emit

fragrance.

Fragrans. Fragrant, sweet-scented. Pres. partic. of fragro, to emit fra-
grance.
Frangula. Buckthorn. From Lat. frango, to break; in allusion to the

brittle stems.

Frasera. American Calumba. Named for John Fraser, an English botani-
cal collector of the eighteenth century.

446 A TEXT-BOOK OF BOTANY.

Fraseri. Of Fraser. Latinized genitive.

Fraxinus. Ash. The classical Latin name. Perhaps from Gr. fypdacu, to
hedge in.

Fulvus-a-um. Yellow, tawny.

Fumaria. Fumitory. From Lat. fumus, smoke. Probably from the nitrous
odor of the fresh roots.

Galeopsis. Hemp nettle. Gr. yaXioipig, a kind of dead nettle.

Galium. Bedstraw. Cleavers. Ancient Greek name of a plant. Perhaps
from yd/la, milk, which is coagulated by some species.

Galla. Nutgall. Ancient Latin word for oak-apple, gall-nut.

Gallicus-a-um. Belonging to Gaul, now France.

Garcinia. Mangosteen. Named for Laurent Garcin, French botanist of
the early part of the eighteenth century.

Gardenia. Cape Jasmine. Named after the author, Alexander Garden of
South Carolina (1757-1829).

Gaultheria. Aromatic wintergreen. Named for Dr. Gaulthier, of Quebec, a,
court physician about the middle of the eighteenth century.

Gaylussacia. Huckleberry. Named for the French chemist, Gay-Lussac.

Gelsemium. Yellow Jasmine. From gelsomino, the Italian ,name of Jas-
mine.

Genista. Woad-waxen. Whin. From the Celtic gen, a bush.

Gentiana. Gentian. The ancient classical name. From Gentius, king
of Illyria, who according to Pliny discovered the medicinal property of
the plant.

Geranium. Cranesbill. The Greek name. From -yspavof, a crane. The
long fruit-bearing beak was thought to resemble the bill of the crane.

Geum. Avens. Latin name of plant, found by Pliny.

Gigartina. Sea moss. From Gr. yiyaprov, a grape stone. From the resem-
blance of the fruit bodies (cystocarps), which appear as elevated
tubercles on the frond or thallus.

Githago. Corn-cockle. Provincial Eng. and Welsh Gith.

Glaber-bra-brum. Smooth, hairless ; referring to the leaves.

Glandulifer-a-um. Gland-bearing. Lat. glandula, gland, -j- fero, to bear.

Glandulosus-a-um. Full of glands, glandulous.

Glaucium. Horned poppy. From Gr. y/lau/cdc, glaucous. From the glau-
cous foliage.

Globulus. Latin diminutive of globus; a little ball, globular; referring to
the button-like form of the fruit.

'Glutinosus-a-um. Glutinous, viscous; referring to the resinous leaves
and stems. From Lat. gluten, glue.

Glycyrrhiza. Liquorice. From Gr. -ytivKve, sweet, + p/C«, root ; referring
to the taste of the root.

Gnaphalium. Cudweed. Everlasting. Ancient Greek name of a downy
plant. Probably allied with KvaQaMov, a lock of wool.

Gossypium. Cotton. From Lat. gossypion, the cotton-tree.

BOTANICAL NOMENCLATURE. 447

Gouania. Chew-stick.

Gramineae. Grass family. From Lat. gramen, grass.

Granatum. Pomegranate. The ancient Latin name.

Gratiola. Hedge hyssop. From Lat. gratia, favor ; because of its supposed

medicinal virtue.

Graveolens. Strong-smelling. Lat. gravis, strong, + oleo, to emit a smell.
Grindelia. Gum-plant. Tar-weed. Named for Prof. D. H. Grindel, a

Russian botanist, who died in 1836.
Guaiacum. Guaiac. From Span, guayaco, the native Haytian name of the

plant.

Guarana. Portuguese name formed from the native Brazilian name.
Gummifer-a-um. Gum-producing. From Lat. gummi, gum, -j- fcro, to

bear.

Guttifer-a-um. Gum-exuding. From Lat. gutta, a drop, + fero, to bear.
Gymnocladus. Kentucky coffee-tree. From Gr. •yv/uv6^) naked, -f /^adof, a

branch, the branches being for long periods destitute of spray.
Gypsophila. From Gr. yi>i/>oc, chalk, gypsum, + 0^ew, to love.
Habenaria. Fringed orchis. From Latin habena, a thong or rein.
Haematoxylon. From Gr. a/^a, blood, -f £v%ov, wood ; relating to the color

of the heart wood.
Hagenia. Cusso. Named after Dr. K. G. Hagen, German physician and

apothecary (1749-1829).
Hamamelis. Witch-hazel. Ancient Greek name of a tree with fruit like

a pear (//j$/f). Of doubtful application, as the fruit is a woody

capsule.
Hanburii. Latinized genitive from Hanbury, an eminent English pharma-

cognosist and traveller.
Hedeoma. Pennyroyal. From Gr. f/6i>off[uie, mint. From //<%, sweet, +

bow, scent.

Hedera. Ivy. The classical Latin name.
Helenium. Sneeze-weed. Ancient Greek name of a plant, said to be

named after Helenus, son of Priam.
Helianthemum. Rockrose. From Gr. fflioc, the sun, -f- avtifpn', flower.

The large flowers open only once, in sunshine.

Helianthus. Sunflower. From Gr. i^oc, the sun, + avttoc, a flower.
Heliotropium. Heliotrope. Turnsole. The ancient Greek name. From

jy/Uoc, the sun, + rpoTny, a turn ; alluding to the flowering at the summer

solstice.

Helleborus. Hellebore. The ancient classical name.
Hepatica. Liver-leaf. From Gr. jjirariK6st belonging to. the liver. The

leaves were thought to resemble the liver in shape.

Herbaceus-a-um. Herbaceous, grassy. From Lat. herba, grass, herbage.
Hesperis. Rocket. Greek name for evening flower. From effirtpa, even-
ing; alluding to the evening fragrance.

Heuchera. Alum root. Named for Prof. J. H. Heucher, who died in 1747.
Hevea. Brazilian rubber tree. From vernacular name heve.

448 A TEXT-BOOK OF BOTANY.

Hibiscus. Rose mallow. The ancient classical name.

Hierochloe. Holy grass. From Gr. Iep6c, sacred, + xUr), grass. Sweet-
scented grasses strewn before church doors on saints' days.
Hippocastanum. Horsechestnut. From Gr. ITTTTOC, horse, + Kaaravov^

chestnut.

Hirsutus-a-um. Hirsute, rough, hairy.
Hispidus-a-um. Rough, shaggy, bristly.
Hordeum. Barley. The ancient Latin name.

Houstonia. Bluets. Named for Dr. William Houston, an English botanist.
Humulus. Hop. Name of uncertain origin. Perhaps from Lat. humus,

ground, alluding to the fact that the plant creeps on the ground unless

supported.
Hydrangea. From- Gr. %6opt water, + ayyeiav, a vessel ; from the shape

of the capsule.
Hydrastis. Golden seal. Orange root. From Gr. vfiup, water, -f- 6pdu

to act, accomplish. Probably with reference to the active properties

of the juice.
Hydropiper. Smartweed. Water pepper. Gr. vdupt water, -j- piper,

pepper.
Hymenocallis. Spider lily. From Gr. i)mfyvt membrane, -f /cdAAof, beauty ;

alluding to the crown.
Hyoscyamus. Henbane. The ancient Greek and Latin name. From Gr.

vf 7 a hog, -f- Ki>a[j.o^ , a bean ; said to be poisonous to swine.
Hypericum. St. John's-wort. The ancient Greek name. Probably from

V7r6, under, -f- kpeint], heather.
Icthyomethia. Jamaica dogwood. From Gr. iffis, a fish, + piOij9 strong

drink, intoxicant.
Idaeus. From Gr. '/daZoc, pertaining to Mt. Ida, near Troy, where the

raspberry once flourished.

Ilex. Holly. The ancient Latin name for the holm oak or holly oak.
Illicium. Star anise. A Latin word meaning an allurement; alluding

to the odor and attractive appearance.
Impatiens. Touch-me-not. A Latin word meaning "that cannot bear or

suffer," from in, not, -f- patiens, enduring ; from the sudden bursting

of the pods when touched.
Indicus-a-um. Pertaining to India.
Inflatus-a-um. Inflated, swollen, puffed up.
Inula. Elecampane. The ancient Latin name.
Ipecacuanha. Ipecac. Portuguese name from Brazilian ipe-kaa-guena;

properly a creeping plant that causes vomiting.

Ipomcea. Morning glory. From Gr. tyt In6gt a worm, -f- bpotos, like ; allud-
ing to the twining stems.

Iris. Fleur-de-lis. Blue flag. From Gr. lpi^t the rainbow.
Islandicus-a-um. Belonging to Iceland.

Isoetes. Quillwort. Ancient name used by Pliny, probably for a house-
leek or evergreen.

BOTANICAL NOMENCLATURE. 449

Iva. Marsh elder. Name of unknown derivation.

Ixina. From native Ixine, at Cumana, Venezuela, where Loefling discov-
ered the plant in 1754.

Jaborandi. Native name of a South American rutaceous shrub.
Jalapa. So called from Jalapa, a town in Mexico, whence it was first
obtained.

Jateorrhiza. Calumba. From Gr. idreipa, healing, -f- p/£a, root ; a healing
root.

Jeffersonia. Twinleaf. Named in honor of Thomas Jefferson.

Juglans. Walnut. Name contracted from Jovis glans, nut or acorn of
Jupiter.

Juncus. Rush. Bog rush. Ancient Latin name; from jungo, to join, the
stems being used for bands.

Juniperus. Juniper. The classical Latin name; probably from juvenis,
young, -f- pario, to produce. Youth-producing ; in allusion to its ever-
green appearance.

Kalmia. Sheep laurel. Named for Peter Kalm, pupil of Linnaeus.

Kamala. Hindoo name of the dusty hairs of the capsules of Mallotus
Philip pinensis, used as an orange dye for silks.

Kino. East Indian name of the dried juice of Pterocarpus Marsupium.

Krameria. Rhatany. Named for Drs. J. G. H. and W. H. Kramer, Ger-
man botanists of the eighteenth century.

Kuhnia. False boneset. Named for Dr. Adam Kuhn, of Philadelphia, who
carried the living plant to Linnaeus.

Kuhnistera. Prairie clover. Named from its resemblance to Kuhnia.

Labiatae. Mint family. From Lat. labium, lip ; referring to the irregular
corolla.

Lacinaria. Blazing star. From Lat. lacinia, the lappet or flap of a gar-
ment ; hence fringed, from the appearance of the flower heads.

Laciniatus-a-um. Slashed, having a fringed border. Lat. lacinia, flap,
lappet.

Lactuca. Lettuce. The ancient Latin name ; from lac, milk ; referring to
the milky juice.

Lactucarium. The inspissated juice of the lettuce (lactuca).

Lamium. Dead nettle. From Gr. Aa^of, throat; alluding to the ringent
corolla.

Lanceolatus-a-um. Armed with little lance or point, lanceolate. From
Lat. lance ola, a small lance.

Langsdormi. Named after M. Langsdorff, Russian consul at Rio, 1829,
from whom Desfontaines received his specimens.

Laportea. Wood nettle. Named for Frangois L. de Laporte, Count of
Castlenan, an entomologist of the nineteenth century.

Lappa. Burdock. The ancient Latin word for burr.

Laterifolius-a-um. Growing by the side of the leaf at its base, as a
laterifolius flower. Lat. latus, side, -f- folium, leaf.

2Q

450 A TEXT-BOOK OF BOTANY.

Lathyrus. Vetchling. Everlasting pea. Ancient name of a plant of

Theophrastus.

Lauraceae. Laurel family. From Lat. laurus, laurel tree.
Lavandula. Lavender. From Lat. lavo, to wash; alluding to the use

made of its distilled water.
Lawsonia. Henna plant. Named for Dr. John Lawson, who lived in the

eighteenth century.

Ledum. Labrador tea. Ancient Greek name of an Oriental shrub.
Leguminosae. Pulse family. From Lat. legumen, pulse.
Lemnaceae. Duckweed family. From Gr. Atum, a water plant.
Lens. Lentil. The ancient Latin name.
Lentiscus. Classical Latin name for the mastic-tree.
Lentus-a-um. Pliant, flexible.

Leonurus. Motherwort. From Gr. Muv, a lion, + ovpa, a tail.
Lepidium. Peppergrass. Classical name of a cress. Also meaning a little

scale; in allusion to the fruit.
Leptandra. Culver's root. From Gr. ^TITOC, slender, + ai%j, avdp6sj

man; referring to the slender stamens.
Leucadendron. From Gr. Aewcdf, white, + Se.vdpov, a tree.
Levisticum. Lovage. Name said to be a corruption of ligusticum.
Ligusticum. Lovage. The ancient Latin name. Derived from Liguria,

an Italian province where the plant abounded.
Ligustrum. Privet. The ancient Latin name.
Liliaceae. Lily family. From Lat. lilium (Gr. heipiov), a lily.
Limonium. Sea lavender. The ancient Greek name; probably from

heipuv. a meadow.

Limonium. Lemon. Ital. limone, from Arabic laimun.
Linaceae. Flax family. From Lat. linum (Gr. Tiivov), flax, linen, thread.
Lippia. Fog-fruit. Named for Agostino Lippi, Italian naturalist.
Liquidambar. Sweet gum tree. From Lat. liquidus, fluid, -f- Arabic ambar,

amber; alluding to the color and fragrance of the exudation.
Liriodendron. Tulip tree. From Gr. faipiov, lily, flower, + 66vdpovt a tree.
Lithospermum. Cromwell. Puccoon. The ancient Greek name. From

Woe, stone, + ffTrtppa, seed ; alluding to the hard nutlets.
Lobeliaceae. Lobelia family. From lobelia. Named after Matthias de

1'Obel, an early Flemish botanist.
Loganiaceae. Logania family. Named after J. Logan, a distinguished

botanist.
Lonicera. Honeysuckle. Named for Adam Lonitzer, German botanist, who

died in 1586.
Loranthaceae. Mistletoe family. From Gr. l&pov, a thong, -{- avttoe,

a flower.

Lotus. Bird's-foot trefoil. An ancient Greek plant name.
Lunaria. Moonwort. From Lat. luna, the moon; alluding to the silvery

septum of the fruit.

BOTANICAL NOMENCLATURE. 451

Lupinus. Lupine. Sun-dial. Ancient Latin name of a plant. From lupus,

a wolf; because these plants were thought to devour the fertility of

the soil.
Lupulus. Diminutive of Lat. lupus, wolf; wolfish, because it chokes the

shrubbery on which it climbs.

Lusitanicus-a-um. Pertaining to Lusitania, the western part of Spain.
Luteus-a-um. Of or belonging to the yellow- weed (luteum) ; hence golden

yellow, flame-colored.
Lychnis. Campion. Ancient Greek name for a plant with flame-colored

flower. From /lir^of, a light or lamp. u

Lycopodiaceae. Club-moss family. From Lycopodium, club-moss.
Lycopodium. Club-moss. From Gr. Awcof, a wolf,-}- vrovst a foot; in

reference to the appearance of the shoots.
Lycopus. Bugleweed, Water horehound. From Gr. Awcof, a wolf, 4- 7rot>f,

a foot; from a fancied likeness in the leaves.
Lythrum. Loosestrife. From Gr. ZvOpov, blood; perhaps because of its

styptic properties.

Macis. Mace. From Gr. fidicep, an Indian spice.
Maclura. Osage orange. Named for William Maclure, an early American

geologist.

Maculatus-a-um. Spotted, mottled. From Lat. macula, a spot.
Magnolia. Named for Pierre Magnol, professor of botany at Montpellier,

France, during the early seventeenth century.
Majalis. Emasculated. From Latin majalis, a barren hog.
Majorana. Marjoram. Old Eng. majoran, late Latin ma/oraca, classical

Latin amaracus.

Major-us. Larger, greater. Comparative of magnus, large.
Mallotus. Kamala. From Gr.//aAAwrd^ woolly, fleecy; the young branches,

leaves and capsules being covered with fine hair or wool.
Malvaceae.- Mallow family. From Lat. malva, mallow.
Mamillosus-a-um. Filled with papillae or " little breasts." From Lat.

mamilla, little breast, in allusion to the stalked cystocarps.
Manna. The dried exudation of Fraxinus Ornus. Gr. parra, a grain,

from Hebrew man, gift.
Marginalis-e. Marginal, belonging to the margin. From Lat. inargo,

margin, edge; with reference to the marginal position of the sori.
Mariana. Carduus. Milk thistle, Virgin Mary's thistle, named from

Maria, Latin name for Mary.
Marilandicus-a-um. Pertaining to Maryland.
Maritimus-a-um. Belonging to the sea. From Lat. mare, the sea.
Marmelos. Bengal quince. From Portuguese marmelo, quince.
Marrubium. Horehound. Latin classical name, derived from the Hebrew

marrob, bitter; a bitter juice.

Marsilea. Named for Aloysius Marsili, an early Italian naturalist.
Marsupium. A pouch, bag. Gr. fiap^vmov; referring to the shape of the fruit.

452 A TEXT-BOOK OF BOTANY.

Mastic. Gr. ^aari^jf) from fiaado/j.at) to chew. Used in the East as a

chewing gum.
Matico. Dried leaves of Piper angustifolium. Said to have been named

from a Spanish soldier, who applied the green plant to a wound and

stopped the bleeding.
Matricaria. Wild chamomile. From Lat, matrix, the womb ; in allusion to

its supposed effect on that organ.
Medicus-a-um. Medical, curative.
Melaleuca. Cajaputi. From Gr. ^Aaj-, black, -f- Aewcdf, white; the bark

of the trunk being black, that of the branches white.

Melilotus. Sweet clover. From Gr. peht, honey, + Awrof, a kind of clover.
Melissa. Balm. From Gr. pehiaca, a bee ; the flowers yielding an abund-
ance of honey.
Menispermum. Moonseed. From Gr. /w^v/f, crescent, -j- anepfj-a, seed; in

reference to the crescent-shaped seeds.

Mentha. Mint. The ancient Latin name. From Gr. fiivdq, mint.
Menyanthes. Buckbean. Probably from Gr. fiqv, month, + &v6oc, a flower.

Perhaps because it blooms for about a month.

Mercurialis. Mercury. Ancient Latin name of a plant; meaning belong-
ing to Mercury, the messenger of the gods.

Methysticum. Kava-kava. Gr. ^etfuan/cof, intoxicating; from /ueOv, wine.
Meum. Spignel. Bear wort. The ancient Greek name (^ou).
Mezereum. French mezereon, from Persian mazriyun.
Microcarpus-a-um. Having small fruit. From Gr. fuitpog, small, +

/capTTOf, fruit.
Mikania. Climbing hempwood. Named for J. G. Mikan, professor in the

University of Prague, who died in 1814.

Milaceus-a-um. Of or pertaining to millet, Lat. milium, millet.
Millef olium. Yarrow. The ancient Latin name ; from mille, thousand, -f-

folium, leaf.
Mitchella. Partridge berry. Named for Dr. John Mitchell, a botanist of

Virginia, eighteenth century.
Mitella. Mitrewort. Bishop's cap. Diminutive of Lat. mitra, a cap;

alluding to the form of the young pod.
Mollis-e. Pliant, soft, mild.
Monarda. Horse mint. Named for Nicholas Monardes, Spanish botanist

and author of the sixteenth century.
Monniera. Hedge hyssop. Named for Prof. L. Guillaume le Monnier,

a French botanist of the eighteenth century.
Monotropa. Indian pipe. From Gr. fi6vof, one, -f- rporr^, a turn ; the

summit of the stem being turned to one side.
Montanus-a-um. Belonging to the mountain, mountainous.
Morus. Mulberry. Ancient Latin name for the mulberry tree.
Mucuna. Cowhage. From the vernacular Brazilian name.

BOTANICAL NOMENCLATURE. 453

Muricatus-a-um. Rough with short, hard points. Lat. murex, a pointed

rock.
Myosotis. Forget-me-not. The ancient classical name. From Gr. ^i>£, a

mouse, ovf, wrdf, the ear. From the short and soft leaves in some

species.
Myrica. Wax myrtle. Bayberry. From Gr. /zup//«7, ancient name of the

tamarisk.

Myristica. Nutmeg. From Gr. pvpifa, to be fragrant.
Myrrha. Myrrh. Ancient classical name for the balsamic juice of the

Arabian myrtle.

Myrtus. Myrtle tree. The ancient classical name.
Napaea. Glade mallow. From Gr. vairr], a woody dell.
Napellus. Little turnip. Diminutive of Lat. napus, a turnip.
Narcissus. The ancient Greek name. From vapurj^ numbness, because of

its narcotic properties. Or, according to others, from Narcissus, a

youth, who according to a myth was changed into this flower.
Nardus. Spikenard. The ancient Greek name.
Nectandra. Bebeeru. Pichury beans. From Gr. VSKTOP, nectar, -f- avyp,

man, nectar stamen.

Nelumbo. Sacred bean. Lotus lily. From vernacular, Ceylon.
Nepeta. Catnip. Cat mint. The ancient Latin name.
Neslia. Ball mustard. Named for J. A. N. de Nesle, French botanist.
Nicotiana. Tobacco. Named for Jean Nicot, a French diplomat, who

was thought to have introduced tobacco into Europe (1530-1600).
Nigella. Fennel flower. Diminutive of Lat. niger, black, from the color

of the seeds.

Niger-gra-grum. Black, dark.
Nobilis-e. Famous, noted, well-born.
Nux-vomica. Lat. nux, a nut, and vomo, to vomit.
Nymphsea. Yellow pond lily. Ancient Greek name for the water lily,

which was dedicated to the water nymphs.
Nyssa. Tupelo. Pepperidge. The Latin name of a water nymph, nurse

of Bacchus; because the original species of the plant grows in water.
Obtusifolius-a-um. Having leaves blunted or rounded at the end. Lat.

obtusus, blunted, -f- folium, leaf.
Occidentalis-e. Occidental. Western.

Odontorhizon. Crawley-root. From Gr. bdavs, a tooth, -f- P%a, a root.
Odoratus-a-um. Emitting a smell, especially sweet-smelling, fragrant.
CEnothera. Evening primrose. An ancient Greek name of a plant.
Officinalis-e. Pertaining to the shop. From Lat. officina, a workshop.
Oleaceae. Olive family. From Lat. olea, olive tree.
Oleum. Gr. IZaiov, olive oil; hence oil.
Onoclea. Sensitive fern. Ancient Greek name of a plant.
Operculina. Turpeth root. Probably from Lat. operculum, a covering.
Opium. Gr. dirtovf poppy juice.

454 A TEXT-BOOK OF BOTANY.

Opulus. Ancient Latin name of a kind of maple.

Opuntia. Prickly pear. Ancient 'Greek name of a plant, perhaps from

'OroDf, a town in Locris.

Orientalis-e. Pertaining to the Orient or East.
Origanum. Wild marjoram. The ancient Greek name. Probably from

bpoft mountain, -j~ -yavog, brightness, joy.
Ornus. Wild mountain ash. The classical Latin word. Perhaps from

Gr. fyof, mountain.
Osmunda. Flowering fern. From Osmunder, Saxon name of the Celtic

divinity, Thor.

Ostrya. Hop hornbeam. Ironwood. The ancient classical name.
Oxalis. Wood sorrel. Ancient classical name ; from Gr. 6ft-?, sour.
Oxycedrus. Prickly cedar. Ancient Greek name ; from 6f i>f , sharp, -j-

jclrf/oof, cedar. Cedar with pointed leaves.
Paeonia. Peony. The ancient Greek name. From llatuv, physician to the

gods.

Palmatus-a-um. Pertaining to a palm, like a palm. From Lat. palina,a palm.
Palustris-e. Fenny, marshy, swampy. From Lat. palus, a marsh.
Panax. Ginseng. Greek name of a plant. From Tra^, all, + d/cof, a cure ;

all-healing, panacea.
Paniculatus-a-um. Having panicles. From Lat. panicula, a tuft or

panicle.

Panicum. Panic grass. Ancient Latin name of Italian panic grass.
Papaver. Poppy. The classical Latin name.

Papyrifer-a-um. Producing papyrus. Lat. papyrus, -f- fero, to bear.
Parviflorus-a-um. Having small flowers. Lat. parvus, small, -|- fios, a

flower.
Passiflora. Passion flower. Adaptation of the Latin flos passionis, flower

of passion. From a supposed resemblance of the parts of the flower

to the implements of the crucifixion.
Pauciflorus-a-um. Having few flowers. Lat. paucus, few, + ftos, a

flower.
Paullinia. Guarana. Named for C. F. Paullini, a German botanist (1643-

1712).

Pedatus-a-um. Having pedates or lobes. Lat. pedo, to supply with feet.
Peltatus-a-um. Peltate or shield-like. Lat. pelta, a shield.
Pcnnalifolius-a-um. Feathered, winged. Lat. pennatus, winged, -j- folium,

leaf.

Penthorum. Ditch stonecrop. From Gr. jr£vre, five, + opof, a rule ; refer-
ring to the quinary order of the flower.
Pepo. Pumpkin. Melon. The ancient Latin word.

Pereirse. Of Pereira. Named in honor of Jonathan Pereira, an Eng-
lish pharmacologist, who visited South America (1804-1853).
Perfoliatus-a-um. Perforate. Stem apparently passing through the leaves.

Lat. per, through, + folium, leaf.

BOTANICAL NOMENCLATURE. 455

Perforatus-a-um. Perforate, having holes as if pricked through. Lat.

perforo, to pierce through.
Persea. Avocado. Ancient name of an Egyptian tree with fruit growing

on the stem.

Persicaria. Lady's thumb. From Lat. persicus, a peach tree.
Petroselinum. Parsley. An ancient Greek plant-name. From Trtrpo,

a rock, + aehivov, parsley.

Phaseolus. Kidney bean. The ancient classical name.
Philadelphus. Mock orange or Syringa. Ancient Greek name of a sweet

flowering shrub ; applied by Linnaeus to this genus.
Phillipinensis-e. Belonging to the Philippine Islands.
Phlox. Greek name of a plant with flame-colored flowers. From 0/U$£

a flame.
Physostigma. Calabar bean. From Gr. ^ixra, a bladder, + <7-/;/z«, a mark,

stigma.
Phytolacca. Pokeweed. From Gr. $vT6v} plant, -f- Ital. lacca, lake color ;

alluding to the coloring matter which the berries yield.
Picea. Spruce. The classical Latin name of the pitch-pine.
Picrasma. Quassia. From Gr. TriKpacjuoc;, bitterness.
Picrotoxinum. From Gr. Tiv/cpdf, bitter, + Togmdv, poison.
Pilocarpus. Jaborandi. From Gr. TrZ/lof, a hair, -f- Kapiros, fruit ; refer-

ring to the shape of the fruit.
Pimenta. Allspice. From Spanish pimicnta, allspice. Derived from Latin

pigmentum, spice.
Pimpinella. Pimpernel. Said to be formed from Lat. bipinnula, equiva-

lent to bipennis, two-winged ; referring to the bipinnate leaves.
Pinus. Pine. The ancient Latin name. Probably akin to pinna, a feather.
Piper. Pepper. The classical Latin name.
Piperitus-a-um. Peppery, pungent. Lat. piper, pepper.
Pipsissewa. Chimaphila. An American Indian name.
Piscipula. From Lat. piscis, fish.
Pistacia. Pistachio. The ancient classical name.
Planifolius-a-um. Having flat leaves. Lat. planus, flat, plane, -f- folium,

leaf.

Plantago. Plantain. The ancient Latin name.
Podophyllum. Mandrake. From Greek 71-0%, foot, + QVAAOV] referring

to the foot-like leaves.
Podostemon. Riverweed. From Gr. iroif, foot, -f- ffTqpuv, thread, stamen ;

the two stamens being apparently raised on a stalk by the side of the

ovary.
Polemonium. Greek valerian. An ancient Greek name of a plant. From

war.

Polygala. Milkwort. From Gr. iroMyafov, the ancient name.
much, + }'a?rz, milk.

45^ A TEXT-BOOK OF BOTANY.

Polygamus-a-um. Having some perfect flowers and others with stamens
only, or pistils only, on the same plant ; polygamous. From Gr. iro/.vs,
much, -f- j-afji£uf to marry.
Polygonatum. Solomon's seal. Ancient Greek name of a plant. From

iroMc, much, many, + y6w, yovaror, knee; having many joints.
Polygonum. Knotweed. The ancient classical name. From Gr.

much, many, + y6vvf knee*; having many knots or joints.
Polypodium. Polypody. The ancient Greek name. From TTOAVC, much,

many, -f- novg, foot ; alluding to the branching rootstock.
Polyporus. Agaric. From Gr. iroM>£, many, + v6pogt a pore ; referring

to the porous texture of the plant.
Populus. Poplar. Aspen. The classical Latin name.

Potentilla. Cinquefoil. Five-finger. Name is a diminutive form of Lat.
potens, powerful; from the reputed medicinal powers of one of the
species.

Pratensis-e. Growing in meadow-land. Lat. pratum, meadow.
Precatorius-a-um. Imploring, beseeching. From Lat. precor, to pray ; in

allusion to the use of the seeds as beads in rosaries.
Primula. Primrose. Cowslip. The name is a diminutive of Lat. primus,

first ; from the flowering of the primrose in early spring.
Procumbens. Lying on the ground. From Lat. procumbo, to incline for-
ward.
Prunifolius-a-um. Having leaves resembling those of the plum tree.

From Lat. prunus, plum tree, -|- folium, leaf.
Prunum. Plum. Classical Latin name for the fruit.
Prunus. Plum, cherry. Classical Latin name for the plum tree.
Pruriens. Itching. From Lat. prurio, to itch ; in reference to the hairs,

which occasion an intolerable itching.

Psyllium. Flea-seed. Ancient Greek name for fleawort.
Psoralea. From Gr. ^wpa/leof, scurfy ; in reference to the glandular dots

on the calyx and pods.

Ptelea. Hop-tree. Ancient Greek name for the elm.
Pteris. Brake or Bracken. Ancient Greek name for a kind of fern. From

irrepov, a wing ; alluding to the pinnate or feathery fronds.
Pterocarpus. From Gr. irrepov, a wing, -f- K.apir6$, fruit ; in allusion to the

winged legumes.
Puber-a-um. Downy.

Pubescens. Downy, hairy, woolly. From Lat. pubesco, to become downy.
Pulegioides. Like fleabane. From Lat. pulegium (Gr. i/wA/uov), fleabane,

+ -o-ei6w, resembling; in allusion to the appearance and odor.
Pulicaria. Fleawort. The ancient Latin name.
Pulmonaria. Lungwort. From Lat. pulmonarius, beneficial to the lungs.

From its supposed curative properties.

Pulsatilla. Pasque flower. From Lat. pulso, to strike, agitate ; of uncertain
application.

BOTANICAL NOMENCLATURE. 457

Punica. Pomegranate. From Lat. punicum, pomegranate tree.

Purpureus-a-um. Purple-colored.

Purshianus-a-um. Adjective formed from Purshia. Named for Fred.

Pursh, a German botanist and author of Flora America Septentrionalis.
Pyrethrum. Pellitory. Feverfew. Ancient Greek name for a hot, spicy

plant.

Pyrus. Pear, Apple. Ancient Latin name for the pear tree.
Quassia. Named for a negro, Quassy or Quash, who prescribed this remedy

as a specific.
Quebracho-bianco. From Sp. quebrantar, to break, -f- hacha, an axe;

in allusion to the hard and tough bark. Blanco, white.
Quercus. Oak. The classical Latin name.
Quillaja. Soap bark. From vernacular quillai, Chili.
Racemosus-a-um. Having racemes or clusters.
Radicans. Rooting. From Lat. radico, to take root; alluding to the fact

that the stems send out roots.
Ranunculus. Crowfoot. Buttercup. The Latin name for a little frog;

some species being aquatic.
Raphanus. Radish. The classical name. From Gr. pa, quickly, + fyaivofiai,

to appear; alluding to the rapid germination.
Repens. Creeping. From Lat. repo, to creep.
Reptans. Creeping. From Lat. repto, to creep.
Reseda. Mignonette. From Lat. resedo, to calm, heal ; from its supposed

sedative properties.

Reticulatus-a-um. Reticulate, net-like. Lat. retia, a net; leaf -veins form-
ing a net-work.

Rhamnus. Buckthorn. The ancient classical name.
Rhaponticus-a-um. Rhapontic. From Lat Rha, the Volga river, -\-

ponticus, pertaining to the Pontic or Black Sea. The rhubarb growing

on the banks of the Rha.
Rheum. Rhubarb. From Lat. Rha, the river Volga, on whose banks the

plant grew.
Rhododendron. Rose-bay. The ancient name. From Gr. p66ov, a rose, +

divdpov, a tree.

Rhus. Sumach. The ancient classical name.
Ribes. Currant. Gooseberry. From Arabic ribds, a plant with an acid

juice.

Ricinus. Castor bean. The ancient Latin name.
Robinia. Locust. Named for John and Vespasian Robin, royal gardeners

of Paris, seventeenth century.

Robustus-a-um. Robust, strong, oaken. Lat. robur, oak.
Rosa. Rose. The ancient Latin name.
Roseus-a-um. Rose-colored, rosy. Lat. rosa, a rose.
Rosmarinus. Rosemary. From Lat. ros, dew, + marinus, belonging to the

sea; from its maritime habitat.

458 A TEXT-BOOK OF BOTANY.

Rostratus-a-um. Beaked, curved, rostrate. Lat. rostrum, a beak.

Rotundifolius-a-um. Having round leaves. Latin rotundus, round, -f-
folium, leaf.

Ruber-ra-rum. Red, ruddy.

Rubus. Bramble. Blackberry. Ancient Latin name, akin to ruber, red.

Rugosus-a-um. Wrinkled, creased. Lat. ruga, a wrinkle.

Rumex. Dock Sorrel. The classical Latin name.

Ruta. Rue. The ancient classical name.

Sabadilla. Cevadilla. From Span, cevadilla. Probably from Lat. cibus,
food, though the seeds are poisonous.

Sabal. Palmetto. From vernacular, Mexico or South America.

Sabina. From Lat. Sabinus, of the Sabines ; a people of Italy who used the
juniper as an incense.

Saccharum. The classical name for sugar.

Saigonicus-a-um. Of Saigon, a city and province in southern Annam.

Salix. Willow. The classical Latin name.

Salvia. Sage. The ancient Latin name. From salvo, to save ; because of
its supposed healing qualities.

Sambuciis. Elder. The old Latin name, perhaps from Gr. aapftvKq, a musi-
cal instrument.

Sanctus-a-um. Holy, sacred, consecrated.

Sanguinaria. Bloodroot. From Lat. sanguinarius, bloody; from the color
of the juice.

Sanicula. Black snakeroot. Sanicle. From Lat. sano, to heal.

Santalinus-a-um. Of the sandal-tree, of . sandal-wood. Gr. oavrakov the

>

sandal-tree.

Santalum. Sandal-wood. The ancient Greek name for sandal-tree.
Saponaria. Soapwort. From Lat. sapo, soap; the juice forming a lather

with water.

Sarracenia. Pitcher plant. Named for Dr. Michel Sarrasin, of Quebec.
Sassafras. The Spanish name. Probably a modification of saxifrage.
Sativus-a-um. Cultivated. Propagated by seed.
Scammonia. Scammony. Classical name of a plant,
Scandens. Climbing. Lat. scando, to climb.
Scilla. Squill. The ancient Greek name for the medicinal squill.
Scirpus. Rush. The ancient Latin name.
Scolopendrium. Adder's tongue. The ancient Greek name. From

<7Ko/o7rw5pa, .the centipede ; alluding to the sori.
Scoparia. Broom-weed. From Lat scopa, a broom.
Scutellaria. Skullcap. From Lat. scutclla, a dish ; alluding to the calyx.
Secale. Rye. Latin name for a kind of grain. From seco, to cut.
Sedum. Stonecrop. Orpine. Latin name of a houseleek. From scdeo, to

sit; alluding to the manner in which the plants attach themselves to

walls and rocks.
Semecarpus. Cashew-nut. From Gr. cny//a, a mark, + nap^of;, fruit.

BOTANICAL NOMENCLATURE. 459

Sempervirens. Evergreen. Lat semper, always, + vireo, to be green.
Senecio. Groundsel. Ragwort. Squaw- weed. From Lat. senex, old man ;

alluding to the hoariness of some species.
Senega. Seneca root. From the Seneca tribe, North American Indians,

who used it as a remedy for snake bites.
Senegal. Name of a country and river in W. Africa. Habitat of the

plant Acacia Senegal.

Senna. Senna leaves. Name derived from Arabic Sana or sena.
Serenoa. Saw palmetto. Named for Prof. Sereno Watson of Harvard

University ( 1826-1892) .

Serotinus-a-um. Late, backward ; relating to the flowers and fruit.
Serpentaria. Snakeroot. The ancient Latin name. From scrpcns, a

serpent.

Serrulatus-a-um. Serrulate, notched. From Lat. serrula, a saw.
Sesamum. Sesame. The classical name of the sesame.
Siliqua. The classical Latin name for a pod.

Silphium. Rosin weed. Ancient Greek name of some resinous plant.
Simaba. Cedron. From vernacular name, Guiana.
Sinapis. Mustard. The ancient Greek name was oivcnrt. The Latin had

both forms, siuapis and sinapi.

Sinensis-e. More commonly Chinensis. Pertaining to China.
Sisymbrium. Hedge mustard. The ancient Greek name of a sweet-scented

plant.
Smilax. Green brier, cat brier. An ancient Greek name for the yew,

and for several plants.

Socotrinus-a-um. Of Socotra, an island east of Africa.
Solanum. Nightshade. The ancient Latin name.

Solidago. Goldenrod. From Lat. solido, to make whole, to heal ; in refer-
ence to its supposed healing properties.
Somnifer-a-um. Sleep-producing. From Lat. somnus, sleep, -f- fcro, to

bear, bring.

Sorbilis-e. Sorbile, fit to be drunk or sipped. Lat. sorbeo, to suck.
Sorbus. Mountain ash. The ancient Latin name.
Sorghum. Derivation uncertain. Probably of Chinese or East Indian

origin.

Spicatus-a-um. Supplied with spikes, spicate.
Spigelia. Pink root. Worm-grass. Named for Adrian von der Spiegel,

Flemish botanist of the seventeenth century.
Spiraea. Hardback. Meadow-sweet. The ancient Greek name. From

ffTreifia, a coil or twist ; from the twisting of the pods in some species.
Squarrosus-a-um. Scabby, scurfy, ragged.
Staphisagria. Stavesacre. From Gr. <rrap/Y, raisin, + «yp«of, wild ; the

fruit clusters resemble wild grapes.
Stillingia. Named for Dr. B. Stillingfleet, English botanist of the eighteenth

century.

460 A TEXT-BOOK OF BOTANY.

Stramonium. Stinkweed. From French stramoine.

Striatus-a-um. Marked with lines or ridges, striate ; Lat. strio, to groove,
mark.

Strophanthus. From Gr. ytrrpwtft, a turn, twist, + avOoc, a flower ; from
the twisted and tailed lobes of the corolla.

Strychnos. The ancient Greek name of a poisonous plant.

Styraciflua. A tree producing storax. From Lat. styrax, storax, + fluo,
to flow.

Styrax. Storax. The ancient Greek name of the storax tree.

Succirubra. From Lat. succus, juice, + ruber, red; — the sap becomes red
on exposure.

Swertia. Chiretta. Named for Emanuel Sweert, herbalist of the seven-
teenth century.

Sylvaticus-a-um. ) _.

0 , }• Pertaining to the woods. Lat. silva, a wood, forest.

Sylvesins-e. )

Symphoricarpos. Snowberry. From Gr. avfi^opeu^ to bring together,

+ Kfl/o7T(5f , fruit ; from the clustered berries.
Symphytum. Comfrey. The ancient Greek name. From avpQi.'u, to cause

to grow together ; because of its reputed healing virtues.
Syringa. Lilac. From Gr. avpiyZ, a pipe ; in reference to the tubular

corolla, or to the use of the wood for pipe-stems.
Tabacum. Tobacco. Span, tabaco, from the Indian word denoting the tube

or pipe used in smoking the plant.
Tamarindus. Indian date. From Arabic tamarhindi, tamar, a dried date, -\-

Hind, India.
Tanacetum. Tansy. From the French name, tanaisie, derived from Gr.

atidvaroc;, immortal.
Taraxacum. Dandelion. From rapdaau, to stir up, disorder; in allusion

to its medicinal properties.

Terebinthina. Turpentine. From Gr. T{p£{3(vOost the turpentine tree.
Teucrium. Germander. Named for Teucer, king of Troy.
Thalictroides. Resembling thalictrum. From Gr. ttahiKrpov, -f- o-e«tyf,

like.

Thalictrum. Meadow rue. Ancient Greek name of a plant.
Thea. Tea. French The, from Chinese tsha.
Theobroma. Cacao. From Gr. 0eoff a god, -+- ppij/ta, food.
Thuja. Arbor Vitae, Cedar. Ancient Greek name for an African tree

with sweet-smelling wood.
Thymus. Thyme. Ancient Greek name. From Ovw, to sacrifice ; alluding

to the sweet odor. .

Tiarella. False mitrewort Coolwort. Diminutive of Lat. tiara, cap;

from some fancied resemblance of the capsules.
Tilia. Linden. Basswood. The classical Latin name.
Tinctorius-a-um. Pertaining to dyeing, containing coloring matter. Lat.

lingo, to dye, color.

BOTANICAL NOMENCLATURE . 461

Tinctorum. Of the dyers. Genitive plural of tinctor, a dyer.

Toluifera. Balsam tree. Said to be formed from Tolu (Santiago de Tolu,

in New Granada), whence balsam was first brought, -f- fero, to bear.
Tomentosus-a-um. Tomentose. Woolly. Lat. tomentum, stuffing.
Toxicodendron. From Gr. ro£//c<n', poison, -j- di-vdpov, tree ; poisonous

shrubs.
Tradescantia. Spiderwort. Named for John Tradescant, gardener to

Charles I.
Tragacantha. Tragacanth. The ancient Greek name for the Astragalus.

From r/jdyoc, a goat, + d/coi^a, a thorn ; in allusion to the character

of the gummy exudation.
Tragopogon. Salsify. Goat's beard. Ancient Greek name of a plant.

From rpriyoc, a goat, -f- TTCJ/WP, beard ; alluding to the pappus.
Triandrus-a-um. Having three stamens. Gr. Tptis, three, -f- avr/pt man.
Tricolor. Having three colors, tricolored. Lat. trcs, three, -{- color, color.
Tricuspidatus-a-um. Ending in three points. Lat. tricuspis, three-pointed.
Trifolium. Clover. Trefoil. The ancient Latin name. Three-leafed.
Trilisa. Vanilla-leaf. Deer's tongue. Name an anagram of Liatris.
Trillium. Wake robin. Birthroot. From Lat. ires, three ; all the parts

being in threes.

Triphyllus-a-um. Having three leaves. Gr. r/?pZc, three, 0ti/Uoi>, leaf.
Triticum. Wheat. The ancient Latin name. From tritus, past participle

of tero, threshed or ground.
Trivialis-e. Common, trivial. Lat. tres, three, -f- via, road ; three roads,

growing along many roads.

Tsuga. Hemlock. The Japanese name of one of the species.
Tuberosus-a-um. Tuberous. Lat. tuber, lump, tumor.
Turpethum. Turpeth. From Persian tirbid, a cathartic ; turbad, a purga-
tive root.
Tussilago. Coltsfoot. The ancient Latin name. From tussis, a cough, for

which the plant is a reputed remedy.

Ulmaria. Queen of the meadow. From ulmus, elm ; hence elm-like.
Ulmus. Elm. The classical Latin name.
Umbellatus-a-um. Umbellated, like an umbel. Lat. umbella, little shade,

umbel.
Umbellularia. Bay-laurel. From umbellula, little umbel, a late Latin

diminutive of umbella.

Uniflorus-a-um. Bearing one flower only. Lat. unus, one, -f- flos, flower.
Urginea. Squill. Sea onion. From Lat. urgeo, to press ; alluding to its

flattened seeds.

Urtica. Nettle. The ancient Latin name.
Usitatissimus-a-um. Most useful, common, familiar ; superlative degree of

usitatus.

Ustilago. Smut, Bunt. An ancient Latin name of a plant.
Uva-ursi. Bearberry. From Latin uva, a grape, + ursi, of a bear.

462 . A TEXT-BOOK OF BOTANY.

Valeriana. Vale-rian. Probably from Lat. valeo, to be strong.

Vanilla. From Spanish vainilla, diminutive of vaina, a sheath, pod; be-
cause its seeds are contained in little pods.

Variifolius-a-um. With varying leaves. Lat. varius, various, changing, -f
folium, a leaf.

Venenosus-a-um. Poisonous, deadly. Lat. vcnenum, poison.

Veratrum. False hellebore. The classical Latin name.

Veronica. Speedwell. Dedicated to St. Veronica.

Versicolor. Having various colors. Lat. vcrto, to turn, change, + color,
color.

Verticillatus-a-um. Disposed in a whorl. Lat. verticillus, diminutive of
vertex, a whirl; referring to the leaves or flowers.

Verus-a-um. True, genuine, original.

Viburnum. Black haw. Arrow-wood. The ancient Latin name.

Victorialis. Ancient Latin name of a plant.

Villosus-a-um. Hairy, shaggy, villous.

Vinifer-a-um. Wine-producing. Lat. vinum, wine, + fcro, to bear.

Viola. Violet. Heart's ease. The ancient Latin name of the genus.

Virginianus-a-um. ) _

,,. . . }• Of or belonging to Virginia.

Virgmicus-a-um. J

Viridiflorus-a-um. Having green flowers. Lat. viridis, green, + flos, a

flower.

Viridis-e. Green.

Virosus-a-um. Having a bad odor, fetid. Lat. virus, an offensive smell.
Vitis. Grape. The classical Latin name.

Vouacapoua. Araroba tree. From vernacular name, Central America.
Vulgaris-e. Common, general, ordinary.
Wisteria. Named in honor of Prof. Caspar Wistar, distinguished anatomist

of Philadelphia.
Xanthium. Clotbur, Cocklebur. Greek name of some plant used to dye

• the hair. From gav66?, } yellow.
Xanthoxylum. Prickly Ash. From Gr. gavOds, yellow, -f- gbfav, wood ;

referring to the color of the roots.

Zea. Maize. Indian corn. Ancient classical name for a kind of grain.
Zeylonicus-a-um. Of or belonging to Ceylon.
Zingiber. Ginger. The ancient Greek name.

CHAPTER V

CLASSIFICATION OF ANGIOSPERMS YIELDING ECONOMIC

PRODUCTS

IN this chapter will be given in natural sequence a list of the
principal orders of plants that yield medicinal and other economical
products. While great stress will be laid upon the plants used in
medicine, yet considerable attention will also be given to the other
economic substances furnished by the angiosperms, as food-
products, fibers, coloring principles, woods, and timbers, as well
as to the plants commonly cultivated for ornamental purposes.
It will be found that the number of plants useful to man is a very
large one, being derived from all the important families, so that in
their consideration the student will gain a rather comprehensive
view of the entire group.

A. CLASS MONOCOTYLEDONE.E.

The Monocotyledons are mainly distinguished as follows : The
embryo has only one cotyledon ; the leaves are mostly scattered and
parallel-veined ; the fibrovascular bundles of the stem are of the
closed type, and the flowers are typically trimerous.

I. ORDER PANDANALES.

This order includes members which are aquatic or marsh plants,
with narrow, elongated leaves and very small, imperfect and
incomplete flowers in spikes or heads.

The TYPHACE;E or Cat-tail family has the flowers borne in
densely crowded terminal spikes, the-staminate flowers being at
the upper end of the spike, while the pistillate flowers which are
beneath are more persistent.

The SPARGANIACE^E or Bur-reed family have the flowers borne
in densely globose heads, the staminate heads being rather small
and near the upper part of the stalk, while the pistillate heads are
larger and situated a short distance below the staminate ones
(Fig. 252).

463

464

A TEXT-BOOK OF BOTANY.

FlG. 252. Bur-reed (Sparganium eurycarpum), a perennial plant flowering throughout
the summer and growing on the borders of ponds, lakes, and rivers throughout the United
States. It grows to a height of 8 to 12 dm., and produces long, ribbon-like leaves. The
flowers are in heads, becoming bur-like from the divergent beaks. — After Brown.

CLASSIFICATION OF ANGTOSPERMS. 465

FlG. 253. Arrow-head (Sagittaria latifolia), a common marsh or aquatic plant and
very widely distributed. The leaves are variable, but almost always sagittate. It produces
naked scapes which are sheathed by the bases of the petioles; the white flowers are produced
all summer. — After Troth.

30

466 A TEXT-BOOK OF BOTANY.

IT. ORDER NAIADALES.

This order, as with other rather primitive orders, is made up
mostly of aquatic and marsh plants, the flowers frequently being
spicated.

The NAIADACE^E or Pond-weed family comprises such genera
as Potamogeton, the common Pond-weed, and Zostera, or Eel-
grass, which is extremely common in bays and estuaries in all
parts of the country, and in many places its collection forms an
active industry. It is used in upholstery work and as a packing
material.

To the ALISMACE^: or Water- Plantain family belong Alisma,
the Water- Plantain, and Sagittaria, or Arrow-head, which is a very
attractive plant (Fig. 253) . Of the latter there are a large number
of species which are widely distributed.

III. ORDER GRAMINALES OR GLUMIFLOR^.

This order is composed of the two families, grasses (Gram-
ineae) and sedges (Cyperacese).

a. GRAMINE^: OR GRASS FAMILY.— The plants of this
family are nearly all herbs having cylindric, generally hollow
culms with swollen nodes. The leaves are exactly alternate, and
have long sheaths which are split or seldom closed, tubufar, and
nearly always with a distinct ligule. The flowers are mostly
hermaphrodite and borne in spikelets with alternate floral-leaves,
the spikelets themselves being borne in spicate or paniculate in-
florescences. Each spikelet (Figs. 255, 256) consists of two
(seldom more) empty glumes, which are the lowest floral-leaves
in each spikelet ; a varied number of flowering glumes, frequently
awned or toothed, are situated inside the empty glumes, and
each of which subtends a short branch (the rhachilla), the latter
bearing an adorsed fore leaf (the pale), which is generally two-
keeled and two-toothed, enclosing two minute scales (lodiculesj
and the flower. The flower has mostly three stamens (there
being six stamens in Oryza and Bambusa), with the anthers versa-
tile, and a simple gynsecium consisting of one carpel having two
styles and a plumose stigma. The ovary is unilocular with one
ascending or pendulous ovule. The fruit is a grain or caryopsis,

CLASSIFICATION OF ANGIOSPERMS.

467

the seed being always firmly united with the thin pericarp (except
in Sporobolus, Eleusine, etc.). The embryo is situated at the
base, on the outer convex surface of the seed, outside the endo-
sperm. On germination the cotyledons remain in the seed.

The endosperm contains numerous starch grains and oil, while
the gluten layer around the endosperm contains proteins. The
number of layers of gluten- or aleurone-containing cells varies in
the different cereals. In corn, wheat, and rye it consists of but
a single layer ; in oat (Fig. 247) and rice, of i or 2 layers ; while in
barley it is made up of 2 to 4 layers.

The Grasses comprise about 3500 species and are distributed
in all parts of the world. While most of the plants are grass-like,

FIG. 254. Diagrams of cross-sections of monocotyledonous flowers: t, stem of plant;
f, bract; s, sepals or outer circle of perianth; p, petals or inner circle of perianth; a, stamens;
c, ovary. A, regular flower of the lily; B, irregular flower of iris. C, flower of an orchid,
in which 1 is the position of the lip and S 8 of the two staminodes. — After Warming.

still some of them, as the bamboos of the Tropics, become quite
tall, having woody siliceous stems and bearing many branches in
the axils of the leaves. The grasses yield the cereal grains forming
so large a proportion of the food of man, and forage constituting
the food of many of the lower animals. The following are some of
the important cereals: Wheat (Triticum sativum and its varie-
ties), corn (Zea Mays), oat (Avena sativa), rice (Oryza sativa),
barley (Hordeum sativum and its varieties), rye (Secale cereale}.
A number of the species yield a sweet cell-sap from which cane
sugar is made, of which the most important are the sugar cane
(Saccharum oMcinarum) and sorghum (Andropogon arundina-
ceus saccharatus and other varieties). (Consult pp. 148, 156, 198.)

468

A TEXT-BOOK OF BOTANY.

A large number of the grasses are used in medicine, one of
which, couch-grass (Agropyron repens), is official.

Agropyron repens is a common perennial grass, forming slen-
der jointed rhizomes, by means of which the plant is extensively
propagated ; the culms vary from one to four feet in height, the
spikelets are 3- to 7-flowered ; and the empty glumes, 5- to 7-nerved,
acute or with a.n awn-like apex.

Hordeum sativum is an annual grass with the flowers in ter-

F!G. 255. Wheat (Triticum): A, zigzag axis or rachis of ear showing the notches
where the spikelets were inserted; B, an entire spikelet; C, a flower with the pales; D, a
flower without the pales, showing the lodicules at the base; E, glume; F, outer pale; G,
inner pale; H, fruit (caryopsis) ; I, longitudinal section of fruit. — After Warming.

minal cylindrical spikes resembling wheat. The spikelets are ses-
sile, i-flowered, and usually in clusters of three on opposite sides
of the notched rachis. The empty glumes are long and narrow,
forming a kind of involucre around the spikelet. It is supposed
that Hordeum sativum is a cultivated form of H. spontaneum
growing in the countries between Asia Minor and other parts of
Western and Southwestern Asia. Three important varieties are
distinguished, depending upon the number of rows of grains in

CLASSIFICATION OF ANGIOSPERMS. 469

the ear. H. sativum distichon includes the plants having 2-rowed
ears, and these are chiefly grown in Middle Europe and England.
H. sativum hexastichon includes the plants having the grains in
6 rows, these having been cultivated since prehistoric times and
furnishes the winter barley. H. sativum vulgare includes the
plants in which the grains are in 6 irregular rows, and these
are cultivated in northern temperate regions. The latter plant
is cultivated in the United States and furnishes the spring or
summer barley, largely used in the preparation of malt.

Zea Mays (Indian Corn) is a cereal plant probably indigenous
to Central Mexico. It is extensively cultivated in the United

FIG 256. Diagrammatic outline of a spikelet: nY, lower glume; <f> Y, upper glume;
nl, outer pale; <f> I, inner pale; 1, 1, lodicules; st, stamens; I-I, main axis; II, lateral axes
or branches.—After Warming.

States and other parts of the world for its grain. From a multi-
ple, primary, somewhat fibrous root arise one or more erect simple
culms, which are grooved on alternate sides in the successive
internodes and from the nodes of which arise aerial secondary
roots. The leaves are alternate and consist of 3 parts: (a) a
blade, which is long, broadly-linear and tapering toward the apex,
the tip being pendulous; (b) a lower sheathing portion which
is open; and (c) a short, translucent, somewhat hairy ligule,
situated between the sheath and the blade. The flowers are
monoecious, the staminate, which are arranged in a terminal pan-
icle, maturing first; the pistillate occur in axillary spikes, the
axes of which constitute the corn cob. They are enclosed in

470 A TEXT-BOOK OF BOTANY.

spathe-like bracts or husks, from which the long filiform styles
(p. 178) protrude. The grain is somewhat ovate or triangular,
flattened, pointed at the base, grooved on one side, indicating the
position of the embryo, from 10 to 15 mm. long and about 10 mm.
broad, more or less translucent, and varies in color in the different
varieties. The constituents of the corn grain are 50 to 75 per cent,
of starch ; about 10 per cent, of proteins ; 4.29 per cent, of a fixed
oil; about 5 per cent, of sugar, and 1.29 per cent, of ash.

There are a large number of varieties and sub-varieties of Zca
Mays, some of the former being ranked as species. The follow-
ing well-defined varieties may be mentioned :

1 i ) Zea Mays everta, to which belong the POP-CORNS. The
size of the ears and grains is about one-half or less that of the
other corns ; the grains have a more or less translucent and horny
endosperm, the cells of the latter containing numerous compactly
arranged polygonal starch grains, which are from 7 to 10 ^ in
diameter and have a central rarefied area from 2 to 7 /x in diam-
eter. It is owing to the structure of the starch grains that the
peculiar popping of the corn grains results when they are heated.
Heating the corn grains at 145° to 160° C. for from 4 to 10 min-
utes causes the bursting of the starch grains, and at the same time
a rupture of the cells and splitting of the pericarp into 4 parts.
The white appearance of the popped grains is due to the inclusion
of air in the bursted cells. During the heating the starch is con-
verted into a soluble form, and this gives popped corn its nutritive
value. Some of the flint and dent corns show a similar tendency
to pop when heated, but it is only in those parts of the endo-
sperm that are horny and the cells of which contain compactly
arranged polygonal starch grains in which the rarefied area is at
least from one-tenth to one-fifth the diameter of the entire grain.
Pieces of the pop-corn, as well as the horny portions of some of
the flint and dent corns, will pop as readily as the whole grains.

(2) Zea Mays indentata yields the DENT or FLINT CORNS, the
grains of which have a corneous (horny) endosperm on the sides
and are indented at the summit, owing to the shrinking of the
cells which contain more cell-sap and less compactly arranged
starch grains.

The starch grains in the cells of the horny endosperm resem-

CLASSIFICATION OF ANGIOSPERMS,

.471

FIG. 257. Carex lurida, one of the Sedge family (Cyperacece), found throughout the
summer in swamps and wet meadows in the eastern and central United States. It is a
perennial grass-like herb with triangular culms, 3-ranked leaves, and with 2 to 4 spikes of
flowers. The genus is a vast one of more than a thousand species, widely distributed and
most abundant in the temperate zones. — After Troth.

ble those of pop-corn, but the starch grains in the other cells are
more or less rounded or slightly polygonal, and vary from 5 to 25 /x.
in diameter; the central rarefied area is either wanting or usually
not more than 2 /x in diameter.

(3) Zea Mays saccharata yields the SUGAR CORNS. While .the

472 A TEXT-BOOK OF BOTANY.

grains are more or less translucent and horny, they have a
wrinkled or shrivelled surface. The cells of the endosperm con-
tain gum-like substances and a relatively small number of nearly
spherical starch grains from 4 to io/x in diameter.

BROOM CORN (Andropogon arundinaceus vulgar -e) is a plant
which is cultivated for the panicles or seed heads, which are used
in the manufacture of brooms. This plant differs from the other
species of Andropogon in that the branches of the panicles are
longer, straighter, and stronger, forming a so-called " brush."

Quite a number of the grasses contain odorous principles, as
Andropogon citratus, which yields lemon-grass oil; A. Schcenan-
thus, which yields gingergrass or geranium-grass oil; A. squar-
rosus, the rhizome of which is known as Vetiver. Coumarin is
found in Vanilla grass (Anthoxanthum odoratum) and white or
Dutch clover (Hierochlcc odorata). Some species of Stipa are
used in the manufacture of paper (Alfa or Esparto) in North
Africa and Spain.

b. CYPERACE^E OR SEDGE FAMILY.— These plants are
all herbaceous, the majority being perennial (seldom annual).
The rhizomes are mostly sympodial (being monopodial, however,
in certain Carices), and the stems are mostly solid and triangular,
without swollen nodes. The leaves are grass-like, generally
arranged in three rows, and the sheath is closed, being mostly
without ligules. The flowers may be hermaphrodite or unisexual,
sometimes dioecious, and arranged in spikes or racemes. The
perianth is wanting or only represented by 6 bristles, or by an
indefinite number of hairs. The number of stamens is 3, with the
anthers attached by their bases to the filament. The gynaecium
consists of 2 to 3 carpels, with one style divided into 2 or 3
branches, and provided with papillae. The fruit is a nut, whose
seed is generally united with the pericarp. The embryo is small
and is centrally situated at the base of the seed, being surrounded
by the endosperm. On germination, the cotyledon is freed from
the seed.

A number of the sedges yield food products, as the rhizomes
of Cyperus esculentus and Eleocharis tuberosa, the latter of which
is used in the manufacture of starch in China and India. Quite
a number of species of Scirpus, Cyperus, Carex, etc., are used in

CLASSIFICATION OF ANGIOSPERMS. 4/3

medicine. Various species of Cyperus (C. scariosus, of the East
Indies, and C. pertenuis, of India) yield ethereal oils and are used
in making perfumery. Cyperus Papyrus is used in medicine and
also furnished the paper of the Ancients.

IV. ORDER PRINCIPES.

In this order is included that interesting group of tropical
and sub-tropical plants the PALMS (Palmae). They are arbores-
cent, having simple unbranched trunks which are terminated by
clusters of leaves, in the axils of which flowers are produced. The
leaves are pinnate (Feather Palms) or palmate (Fan Palms)
and often very large. The petiole is well developed, with an am-
plexicaul, more or less fibrous sheath. The inflorescence is usually
lateral, in some cases forming a large spadix with a woody, boat-
shaped spathe. In comparison the individual flowers are very
small. The fruit is either a berry, as in the Date palm, or a drupe,
as in the Cocoa-nut palm, generally I -seeded and with a large
horny or bony endosperm, as in the Date palm (p. 135) and
Phytelephas macrocarpa, the latter of which yields vegetable ivory,
used in the making of buttons (Fig. 258).

The fruit of the saw palmetto [Serenoa (Sabal) serrulata],
one of the fan palms, is official. The saw palmetto is characterized
by having a creeping, branching root-stock or rhizome, one end
of which rises a short distance above ground, this portion being
surmounted by a dense crown of leaves. The petioles are slender
and spinose on the edges ; the blade is fan-shaped and consists of
a number of palmate divisions which are slightly cleft at the apex.
The inflorescence is densely tomentose and shorter than the leaves.
The fruit is a i -seeded drupe.

The palms yield a number of useful products. The Betel-nut
palm (Areca Catechu) produces a seed having medicinal proper-
ties (Fig. 259). The seeds, known as ARECA NUT, are 20 to 25
mm. long, conical, grayish-brown, with numerous spiral, reddish
veins, heavy, hard, somewhat aromatic, astringent, and slightly
acrid. They contain about o.i per cent, of an oily liquid alkaloid,
arecoline, which chemically and in its physiological action resem-
bles pelletierine ; 14 per cent, of tannin, resembling catechutannic
acid ; gallic acid ; a red coloring principle ; and 14 per cent, of a

474

A TEXT-BOOK OF BOTANY.

fixed oil. They also contain 3 other alkaloids: arecaine, arecai-
dine, and guvacine, but these do not seem to give the drug its
properties.

CARNAUBA-WAX is obtained from the Carnauba-palm of Brazil
(Copernicia cerifera). The wax exudes from the surface of the
young leaves and is obtained by boiling them with water. DRAGON'S

FIG. 258. Vegetable Ivory, the endosperm of the seeds of a Central American palm
(Phytelephas macrocarpa). The fruits are produced near the ground, are nearly globular,
measuring about i meter in circumference, and weigh about 14 pounds each. They are
covered with a woody spinose wall (A), and enclose a number of drupes (B), each of which
contains a single hard seed (C). The latter contains a hard, white, fine-grained endosperm
(D); it is used in making small articles of turnery, as buttons, etc. — Reproduced by permis-
sion of The Philadelphia Commercial Museum.

BLOOD, a bright red resinous substance, is obtained from the juice
of the fleshy fruit of Calamus Draco. It consists chiefly of resin,
some tannin, and about 3 per cent, of benzoic acid.

The Oil palm (Elccis guineensis) of equatorial West Africa
yields a drupe with an oily sarcocarp, from which, by means of
pressure or boiling with water, PALM OIL is obtained. The Cocoa-
nut palm (Cocos nucifera) yields the COCOA NUT of the market,

CLASSIFICATION OF ANGIOSPERMS. 475

and is probably one of the most useful palms to the natives, fur-
nishing, as it does, food, clothing, utensils of all kinds, building
materials, etc. The Sago-palms (Metroxylon Rumphii and M.
Iccve) yield SAGO, which is prepared by washing out the starch
from the cut stems and subsequently heating it. A tree 15 years
old yields from three to four hundred kilograms of sago starch.
The Date palm (Phoenix dactylifera) yields the DATES of the

FlG. 259. A number of Areca-nut palms (Areca Catechu) growing in Ceylon. The
stems are slender, attaining a height of 25 meters or more, with a diameter of 3 to 4 dm.
and bearing a cluster of leaves at the summit. The palm is also known as the Betel-nut
palm, and is extensively cultivated throughout tropical India. — Reproduced by permission
of The Philadelphia Commercial Museum.

market, and it is interesting to note that since very early times
the fruits produced by the growers in the Orient have been the
result of artificial or hand-pollination.

V. ORDER ARALES OR SPATHIFLOR/E.

This order includes two families which are markedly different
in their habits: (i) The Aracese, which are rather large herbs
with an inflorescence known as a spadix and consisting of a fleshy

476

A TEXT-BOOK OF BOTANY.

FIG. 260. Fruits and iiowers of several of the palms. A, cluster of flowering spikes
of the cocoanut palm (Cocos nucifera); B, number of the young fruits of the cocoanut
palm; C, cluster of the ovoid fruits of the betel-nut palm (Areca Catechu); D, compound
inflorescence of drooping spikes of the kittul (Ijittool) palm (Caryota urens); E, large clusters
of deltoid fruits of kittul palm. — Reproduced by permission of the Philadelphia Commercial
Museum.

The cocoanut palm yields a larger number of economic products than any other tree
in the world; the fruit is edible and yields the cocoanut oil, the sap produces an alcoholic
beverage, the leaves are used for making useful articles, and the wood is employed in cabinet
making.

The Betel-nut palm yields a number of valuable products, the most important being
the seed, which is not only used to stimulate digestion, but is used in many religious cere-
monies, as well as in regulating the intercourse of the more polished classes of the East.
The base of the leaf stalks of the kittul palm yield a fiber which is elastic, shows considerable
tenacity, and is used in the making of brushes for brewers' use.

CLASSIFICATION OF ANGIOSPERMS. 477

FIG. 261. Jack-in-the-Pulpit, or Indian Turnip (Aris&ma triphyllum) , a very common
perennial herb growing in woods and thickets of the eastern and central parts of the United
States and Canada, and characterized by i or 2 leaves which are divided into 3 ellfptical-
ovate, pointed leaflets and a characteristic spathe of a greenish color, frequently purple-
striped and curving in a broad flap over the top of the club-shaped spadix. The plant
produces a turnip-shaped corm with an intensely acrid juice. — After Troth.

478

A TEXT-BOOK OF BOTANY.

spike, which is subtended or enclosed by a large bract known as
a spathe, as in the Calla-lily, where it is large and white, and (2)
the Lemnaceae or duckweed family, which is composed of minute,

FlG. 262. Skunk Cabbage (Symplocarpus fcttidus), a perennial herb producing a very
thick rhizome, from which arise in the early spring the flowers crowded on a spadix sur-
rounded by a large, shell-like spathe which barely rises out of the ground and is striped or
spotted with purple and yellowish-green. These are followed by a cluster of ovate, cordate
leaves becoming 3 to 6 dm. long. In the illustration are shown 4 of the spathes, the one at
the left being cut open to show the globular or ovoid spadix, and a single leaf unfolding. —
After Troth.

floating, thalloid plants that develop one or more flowers on the
margin or upper surface of the thallus.

ARACE^E OR ARUM FAMILY.— The plants belonging to
this family are perennial herbs with tuberous or fleshy rhizomes

CLASSIFICATION OF ANGIOSPERMS.

479

and simple or compound leaves which are usually long-petioled.
The spadix is densely flowered, the staminate flowers being above
and the pistillate below on the same axis, or the plants are wholly
dioecious. The perianth when present consists of 4 to 6 scale-like
segments. Frequently the spadix is subtended or enclosed by a
more or less showy spathe. The fruit is usually a berry, some-
times a utricle.

FIG. 263. Water Arum (Calla palnstris) , showing portion of rhizome, the broadly
ovate and cordate leaves, and the inflorescence, which consists of a cylindrical spadix and
an elliptical spreading spathe.

A number of the plants of this family have medicinal proper-
ties, and one of them yields the unofficial drug CALAMUS. The drug
is derived from sweet flag (Acorus Calamus), a plant common
in swamps and along streams in the Eastern United States, and
characterized by its long, narrow, linear, bilateral leaves, which
are from 6 to 18 dm. in height and about 25 mm. in width. The
inflorescence is a spike-like spadix having greenish-yellow flowers.

Many of the Araceae possess an acrid juice. The acridity is

480 A TEXT-BOOK OF BOTANY.

probably due either to saponin or an acrid volatile principle rather
than to raphides of calcium oxalate. Frequently these principles
are dissipated or destroyed on cooking, and the plants are then
used as food, as the WATER ARUM (Calla palustris), which on
account of its acrid principles is used as a remedy for snake bites
when in the fresh condition, but which on drying loses- its acridity
and being rich in starch is used as a food (Fig. 263). To this
family also belong Jack-in-the-pulpit, or INDIAN TURNIP (Ari-
sama triphyllum), the acrid corm of which is used in medicine
(Fig. 261) ; SKUNK CABBAGE (Symplocarpiis fcetidus), the fetid
rhizome of which has medicinal properties (Fig. 262). A number
of plants of the Arum family are rich in starch, as the tubers of
Xanthosoma edule of Surinam, which contain 62 per cent, of
starch.

VI. ORDER XYRIDEALES OR FARINOSE.

The plants are mostly perennial herbs of tropical and sub-
tropical America. The order includes a number of families,
among which is BROMELIACE^E, to which the pineapple (Ananas
sativus) belongs. PINEAPPLE is a native of Brazil and is now cul-
tivated in warm countries of the eastern and western hemispheres.
The fruit contains a proteolytic enzyme resembling trypsin and
also a milk-curdling ferment. The bast fibers of the leaves are
used for textile purposes. Some of the Bromeliaceae are epi-
phytic (air-plants), the best known member being probably the
FLORIDA MOSS (Tillandsia usneoides), which is used in upholstery
(Fig. 264).

The family Commelinaceae is represented in the United States
by Commelina or day-flower, some species of which have medic-
inal properties. The roots of some tropical species contain saponin,
as C. deficiens, of Brazil. The rhizomes of a number of species
of Commelina contain notable quantities of starch and are edible.
The spiderworts (Tradescantia) common in rich soil in the
United States, and the Wandering Jew (Tradescantia Zebrina)
commonly cultivated as an ornamental plant, also belong to this
family. To the PONTEDERIACE^: belong several perennial aquatic
or bog plants, whose leaves are usually thick or in some cases long
and grass-like. The flowers are frequently arranged in Spikes
subtended by leaf -like spathes (Fig. 265).

CLASSIFICATION OF ANGIOSPERMS.

481

482

A TEXT-BOOK OF BOTANY.

FIG. 265. Pickerel Weed (Pontederia cor data), a common aquatic herb growing along
the margin of slow streams. It is a very hardy plant occurring far north and grows best in
water ten or twelve inches deep. It produces long-petioled leaves and a single stem bearing
a spike of violet-blue, ephemeral flowers. — After Troth.

CLASSIFICATION OF ANGIOSPERMS. 483

I

FIG. 266. Small Solomon's Seal, also commonly known as true Solomon's Seal (Poly-
gonatum biflorum). It is a perennial herb with lance-oblong, sessile leaves, in the axils of
which are usually two nodding greenish flowers. The plant grows in moist woods or wooded
hillsides, and receives its common name from the creeping knotted rhizomes, on the upper
surface of which are usually one or more prominent circular scars, formed upon the decay
of the aerial shoots. — After Biown.

484

A TEXT-BOOK OF BOTANY

FIG. 267. False Solomon's Seal or False Spikenard (Smilacina racemosa), a perennial
herb with a somewhat stout stem, a number of alternate parallel-veined leaves and a terminal
raceme of whitish, sometimes fragrant, flowers. It forms a horizontal knotted rhizome, on
the upper surface of which are found circular scars. It may be found growing in under-
brush in moist woods. — After Brown.

CLASSIFICATION OF ANGIOSPERMS. 485

VII. ORDER LILIALES OR LILIIFLORvE.

The plants of this order are mostly perennial herbs with rhi-
zomes, tubers, bulbs, or fibrous roots. The leaves are parallel-
veined.

a. LILIACE^E OR LILY FAMILY.— The plants are the
most typical of the Monocotyledons. They are scape-like herbs
with bulbs ; the flowers are symmetrical, and the perianth is parted
into 6 more or less distinct segments (Fig. 123) ; the anthers are
introrse. The ovary is free, 3-locular, with a single style, and the
fruit is a 3-locular, loculicidally dehiscent capsule.

The Liliaceae is one of the most important families, containing
about 2500 species, many of which are of great economic interest.
Quite a number are cultivated on account of the beauty and fra-
grance of their flowers. Among the latter are the hyacinth, lily,
lily-of-the-valley, tuberose, tulip, and yucca. Of those yielding
food products we have asparagus, being the young shoots of
Asparagus officinalis. The edible bulbs include the onion (Allium
Cepa], garlic (Allium sativum), the leek or scullion (Allium
Porrum), and chives (Allium Schcenoprasum). A number of
the Liliacese are among the common wild flowers, as swamp pink
(Fig. 272), bellwort (Uvularia), lily (Lilium), dog's-tooth violet
(Erythronium), Star of Bethlehem (Ornithogalum), False Solo-
mon's Seal (Fig. 267), True Solomon's Seal (Fig. 266), Indian
Cucumber- root (Medeola), colic-root (Fig. 271), cat brier
(Smilax), etc. The following plants are of medicinal interest :

Veratrum viride is a plant 2 to 8 feet high, which is charac-
terized by the broad, clasping, strongly plicate leaves, and by hav-
ing the flowers in large terminal panicles (Fig. 268). The plant
is found in swamps and wet woods in the United States in spring
and early summer. The rhizome is upright, and it with the roots
is used in medicine. The plant, including the rhizome, closely
resembles the Veratrum album of Europe.

Colchicum autumnale. — This is the autumnal-flowering colchi-
cum, a perennial herb but a few inches high which arises from a
corm and bears proportionately large lilac-colored flowers. The
fruit consists of 3 follicles containing numerous seeds. The corm
and seeds of this and other species of Colchicum are used in

486

A TEXT-BOOK OF BOTANY.

FIG. 268. Flowering specimen of Veratrum tiride, showing the spreading, spike-like
racemes and the parallel-veined leaves.

CLASSIFICATION OF ANGIOSPERMS. 487

medicine. Among the species yielding large corms and extensively
cultivated is Colchicum Burmanii (Fig. 269).

Aloe species. — The stems are about a meter high and bear at
the summit a cluster of thick, succulent leaves which are lance-
olate and spinous-toothed (Fig. 270). The inflorescences are in
long spikes which are quite showy and characteristic for the differ-
ent species. Aloe Perryi, which yields the SOCOTRINE ALOES,
possesses leaves with white spines and flowers that are orange-red
or scarlet at the base, the stamens being unequal ; Aloe vera, which
yields the BARBADOES or CURACAO ALOES, has leaves with yellow
or reddish spines and yellow flowers in which the stamens are as
long as the corolla ; Aloe ferox and some other African species,
which yield CAPE and UGANDA ALOES, have flowers in close spikes,
the petals being white and marked by green lines, and the stamens
much longer than the corolla. The inspissated juice is official
in all the pharmacopoeias.

Urginea maritinia, which yields the drug squill, is character-
ized by its large, onion-like bulb, from which arise ten to twenty
broadly lanceolate, grayish-green leaves ; and by having the in-
florescence in long spikes consisting of whitish flowers which have
a distinctly purple stripe on each division of the perianth.

Convallaria majalis or Lily-of-the-valley is a plant which is
well known. It produces a raceme of delicately odorous white
flowers and beautiful oblong leaves with prominent parallel veins.
The rhizome and roots are official.

Smilax species. — The drug sarsaparilla is yielded by at least
four different species of Smilax. These are mostly vines with
woody or herbaceous, often prickly stems and leaves with petioles
which have a pair of persistent tendril-like appendages. The
flowers are small, mostly greenish, dioecious and in axillary umbels.
The fruit is a globose berry. Not a great deal is known of the
species which yield the drug, with the exception of Smilax medica,
which yields the Mexican or Vera Cruz sarsaparilla. In Smilax
medica the leaves vary from more or less cordate to auriculate-
hastate; in Smilax officinalis, which yields the native Jamaica
sarsaparilla, they, are ovate, as they are also in Smilax papyracea,
which yields Para sarsaparilla. The Jamaica Sarsaparilla, official
in the British Pharmacopoeia, is obtained from plants of Smilax

488 A TEXT-BOOK OF BOTANY.

ornata growing in Costa Rica and subsequently shipped to Jamaica.
Nothing is known of the plant yielding Honduras sarsaparilla,
although this drug has been in use for nearly four centuries. It

FIG. 269. Floweiing plant of Colchicum Burmami, a form producing very large corms a.nd
extensively cultivated in Holland.

is said to be derived from Smilax officinalis. The sarsaparilla
plants have short rhizomes which give rise to long roots, which
are the part used in medicine.

A DRAGON'S BLOOD, resembling that derived from Calamus

CLASSIFICATION OF ANGIOSPERMS. 489

Draco, is obtained from Dracccna Draco, a tree growing in the
Canary Islands. Some of the trees of this species are of historic
interest, as the dragon tree of Orotava, which is 46 feet in circum-
ference at the base.

A number of the plants of this family contain saponin, as the
species of Smilax. Some contain coniferin and vanillin, as Aspar-
agus officirtalis. Some of the group contain glucosidal principles
which under the influence of ferments yield ethereal oils contain-

FlG. 270. A field of Aloe plants, growing in the Riversdale District, Cape Colony.
The stems are simple, with one or more clusters of leaves; the latter are from 3 to 6 dm. in
length, fleshy and very thorny-prickly at the margin. — Reproduced by permission of the
Philadelphia Commercial Museum.

ing sulphur, as the various species of Allium. Garlic (Allium
sativum) contains a glucoside, allisin, which on hydrolysis with an
oxidase (allisin) forms the essential oil of garlic. A number also
are quite poisonous when fresh but edible when cooked.

b. AMARYLLIDACE^E . OR AMARYLLUS FAMILY.—
This group is of special interest because it includes the Agave
or Century plant. This is a characteristic genus of plants of the
hot and arid regions of North America. The best known of these

490

A TEXT-BOOK OF BOTANY.

is the CENTURY PLANT (Agave americana), which is one of the
most important economic plants of Mexico. The stem axis of
the plant is very short and the thick, fleshy leaves form a tuft at

FIG. 271. Plant of Aletris farinosa showing characteristic rosette of lanceolate leaves
at the base and portion of long slender scape with numerous tubular flowers. The plant is
common in dry coniferous woods in the eastern part of the United States.

the summit. The leaves are lanceolate, with spinose margins, and
furnished with stout terminal spines. The leaves as well as the
roots contain a large amount of mucilage which retains water and

CLASSIFICATION OF ANGIOSPERMS.

491

FIG. 272. Swamp Pink (Helonias bullata) is a rather rare plant found only in certain
localities, particularly in wet places, extending from southern New York to Virginia. It
produces a tuberous root-stock, and the evergreen leaves are clustered near the base of a
naked scape which bears in the early spring a short raceme of purplish flowers. This
should not be confounded with the plant yielding the drug known as Helonias or false
unicorn root, the latter being derived from Chamcelirium luteum, and at one time known
as Helonias dioica. — After Troth.

492 A TEXT-BOOK OF BOTANY.

thus helps to adapt the plants to these arid regions. The plants
grow slowly and may flower when they are ten or twelve years old.
The Agaves contain saponin and other principles of medicinal
value. They yield a number of other products, as follows :
PULQUE, a fermented drink of the Mexicans ; MEZCAL, a distilled
drink resembling rum; various fibers, as SISAL HEMP, " Hene-
quen " or " Sacci/' etc. Other members of the Amaryllidacese
likewise find use as medicines and as foods, many of them being
cultivated as ornamental plants, as Narcissus, Hymenocallis,
Crinum, and Amaryllis.

c. DIOSCOREACE.E OR YAM FAMILY.— The plants be-
longing to this family are twining shrubs or herbs with tubers
either above or below ground. The general characters of the
plants are shown in the wild yam-root (Dioscorea villosa) of the
United States (Fig. 180). Several species, notably, D. Batatas,
yield the YAMS or Chinese potatoes of commerce.

Many of the species of Dioscorea, as well as other members of
this family, contain active principles which, like those of the
Aracese and Liliacese, are destroyed on heating. The rhizome of
Tamus communis contains saponin, and Rajania subamarata con-
tains tannin.

d. IRIDACE^E OR IRIS FAMILY.— The plants of this fam-
ily are perennial herbs with mostly equitant (bilateral) leaves
and horizontal rhizomes, or corms. The flowers are regular or
irregular and with a petalloid stigma (Fig. 254, B).

Iris versicolor is a flag-like plant, commonly known as the
LARGER BLUE FLAG, and found abundantly in the marshes and wet
meadows of the Eastern United States. It is distinguished by its
tall* stems and sword-shaped, somewhat glaucous leaves. The
flowers are violet-blue. The rhizome somewhat resembles that of
calamus, but is of a dark brown color and contains 25 per cent, of
acrid resins, a volatile oil, starch, and tannin.

Iris florentina, which yields the ORRIS ROOT of commerce (Fig.
190), is a plant cultivated in Middle and Southern Europe, and
closely resembles the above-mentioned species. The rhizome con-
tains a volatile oil resembling that found in violets, and is used
in perfumery. Orris root is also obtained from Iris germanica
and /. pallida. The violet odor is developed on keeping the rhizome
a vear or two.

CLASSIFICATION OF ANGIOSPERMS. . 493

Crocus sativus, the orange-red stigmas of which have been used
in medicine since ancient times, is an autumnal-flowering plant.
The flowers are lilac-purple, somewhat like those of Colchicum,
and occur at the summit of a scape rising 15 to 20 cm. above
ground. The leaves are linear and rise directly from a more or
less globular corm. The plant is cultivated in Spain and other
parts of Europe and in the United States as well. The stigmas
constitute the drug SAFFRON (Crocus), which was formerly official,
and contain a coloring principle, I part of which will impart a
distinct yellow color to 100,000 parts of water. Saffron contains
a yellow glucoside, CROCIN, which is soluble in alcohol but not in
water, and is colored blue by sulphuric acid. The drug also con-
tains 7.5 to 10 per cent, of a volatile oil, which appears to be
derived from a coloring principle that resembles carotin ; and the
bitter principle picro-crocin.

e. JUNCACE^ OR RUSH FAMILY.— These are grass-like
marsh plants, which are distinguished by the fact that the flowers
are small, with a 6-parted glumaceous perianth, and the fruit is a
loculicidally dehiscent capsule. The stems are mostly solid, slen-
der, usually arise in tufts from the rhizome, and are characterized
by stellate parenchyma cells, among which are large, intercellular
spaces, the latter also being characteristic of the leaves. The
rushes are principally found in cold and temperate regions.

Several species of Juncus and Luzula have been used in medi-
cine, particularly in Europe. The seeds of Luzula compestris,
a common wood rush of the United States naturalized from
Europe, are edible. Soft rush (Juncus effusus) and Hard rush
(/. conglomerate) are used in Japan in the manufacture of rush
matting. In Holland the rush is grown on the embankments
along the coast to prevent the action of the tides.

VIII. ORDER SCITAMINALES OR SCITAMINE^E.

The plants of this order are mostly found in the Tropics and
are perennial herbs with fleshy rhizomes. The leaves are large,
more or less elliptical and pinnately veined. The leaf sheaths close
tightly around each other and form a kind of false stem. The
flowers are epigynous, unsymmetrical or zygomorphic, and fre-
quently only one stamen is completely developed.

494 A TEXT-BOOK OF BOTANY.

a. THE ZINGIBERACE;E OR GINGER FAMILY is dis-
tinguished from the other Scitaminese by the fact that the seeds
have endosperm as well as perisperm. The plants are rich in
volatile oils, and a number are used in medicine and perfumery.

Zingiber officinale yields the official ginger (Fig. 273). From
a creeping, fleshy, branching and laterally compressed rhizome
(Fig. 187) arises a stem about i M. high bearing numerous lanceo-
late leaves. The flowering stalk arises directly from the rhizome,
terminating in a spike which bears flowers having greenish-yellow
petals with violet or purple stripes.

Elettaria Cardamomum (E. repens) yields the cardamom of
the several pharmacopoeias (Fig. 237). The plant has a leafy as
well as floral stem which rises from a tuberous rhizome. The
leaves are broadly lanceolate. The flowers are greenish-white,
the labellum (consisting of two petal-like staminodes) being bluish.
The fruit is a capsule, and the seeds are the part used in medicine.

The so-called PARADISE GRAINS are the seeds of Amomum
Melegueta growing in Western Africa. They are about 3 mm. in
diameter, dark brown, nearly smooth, friable, and contain a vola-
tile oil.

GALANGAL, which is used in perfumery, is the rhizome of
Alpinia Galanga growing in the East Indies and cultivated in
China and Bengal. It is frequently referred to as " Galangal
major " to distinguish it from the rhizome of Alpinia officinarum
growing in China near Hainan. Galangal occurs in short, branched
pieces of a reddish-brown color, with numerous circular scars,
and has an aromatic and pungent taste. It contains 0.5 per cent,
of a volatile oil, the principal constituent of which is cineol ; a
pungent principle, galangol ; an acrid, pungent resin ; 25 per cent,
of starch ; and three crystalline principles.

CURCUMA or TURMERIC is the rhizome of Curcuma longa, a
reed-like plant which is largely cultivated in India and other
tropical countries. In preparing the rhizome for market it is sub-
jected to a scalding or parboiling process which agglutinates the
starch in the cells. While turmeric is used as a condiment, it is
also used on account of its color as an adulterant of mustard,
rhubarb, and other articles, but is very easily detected. Several
forms of curcuma are found in commerce, as " round curcuma,"

CLASSIFICATION OF ANGIOSPERMS. 495

consisting of the main rhizome, and " long curcuma," composed
of the short branches. They occur in cylindrical or ovoid pieces,

FIG. 273. Zingiber officinale, the rhizome of which constitutes the ginger of the market.
Entire plant showing rhizome and roots, a leaf-branch and a flower-branch, as also scars of
previous year's growth after decay of leaf- and flower-branches. A, entire flower; B, sec-
tion of flower showing beak-like appendage at the apex of the fertile stamen, which encloses
the style; C, three-parted labellum or irregular segment of corolla showing 2 tooth-
like staminodes (rudiments of stamens) at the base; D, the ovary with lower portion of
style and two epigy nous, filiform processes which secrete nectar; E, apex of funnel-shaped,
fringed stigma. — After Berg and Schmidt.

2 to 5 cm. long, of a yellowish-brown color externally, bright yel-
low internally, and aromatic odor and taste. Curcuma contains

496 A TEXT-BOOK OF BOTANY.

i per cent, of volatile oil containing phellandrene and turmerol ; 0.3
per cent, of a yellow crystalline principle, CURCUMIN, which is
soluble in alcohol, sparingly soluble in water, forms reddish-brown
solutions with alkalies and is converted into vanillin with weak
oxidizing agents. It also contains considerable starch and a small
quantity of an alkaloid.

Other families of the Scitamineae are of great importance on
account of the food-products obtained from them, as the Musa-
cece, which contains the group of plants to which the BANANA
(Musa paradisiaca and M. Sapientum) belongs. To the Canna-
cece belong the cultivated Cannas, one of them, Canna edulis,
being grown extensively in the West Indies and Australia as a
vegetable, and another, Canna coccinea, which grows in the West
Indies and South America, furnishing " Tous les mois," the
arrow-root starch of the English and French. To the Maranta-
ce& belongs Maranta arundinacea, which is cultivated in tropical
America, and the rhizome of which yields the starch, MARANTA
ARROWROOT (Fig. 88, 5), and is largely used in the preparation of
infants' food.

IX. ORDER ORCHIDALES OR MICROSPERM^E.

The most important family of this order is the ORCHIDACE^E or
ORCHID FAMILY. The orchids are the most highly specialized
of the Monocotyledons. They are perennial herbs with diverse
habits, many tropical species being epiphytes, and of varying mor-
phological structure, which is particularly evident in the zygo-
morphic flowers. The perianth consists of 6 segments. The 3
outer correspond to sepals and are similar. Two segments of the
inner circle correspond to petals and are alike, while the third,
which is known as the LIP, is remarkably modified, being usually
larger, often spurred, and frequently reversed, being turned for-
wards and downwards by the twisting or torsion of the ovary.
Only one of the stamens — the anterior of the external whorl — is
developed and bears an anther. The other stamens are entirely
wanting or present as staminodes (except in Cypripedium and the
Apo-stasieae). The filament is united with the style to form a
column, the so-called " stylar column," and the anther is thus
placed on its apex, and behind the stigma. The 3 carpels form a
unilocular ovary with 3 parietal, deeply bifid placentae. The fruit

CLASSIFICATION OF ANGIOSPERMS.

497

is a pod or capsule, which dehisces mostly by means of 6 valves,
and contains numerous minute seeds, which are without endo-
sperm, and the embryo of which lacks frequently any trace of
external organs. The seed-coat is membranous and loose.

FIG. 274. A fruiting plant of Vanilla planifolia, an epiphytic orchid, which is indige-
nous to Mexico and extensively cultivated in tropical countries, especially in Mexico and
Java. The photograph is of a plant growing in Dominica, an island of the West Indies,
and shows the long, elliptical leaves, also some of the long, slightly curved, slender pods.
The latter are not fragrant, but develop their characteristic aroma by a process of slow
curing. — Reproduced by permission of The Philadelphia Commercial Museum.

Vanilla planifolia, which yields the official vanilla, is a high-
climbing plant with long internodes and distinct nodes from which
arise more or less oval or broadly lanceolate, somewhat fleshy
leaves and also commonly a single aerial root. The long stem
is terminated by a raceme, flowers also arising in the axils of the
32

498

A TEXT-BOOK OF BOTANY,

FIG. 275. Moccasin Flower or Pink Lady's Slipper (Cypripedium acaule), one of the
commonest and most beautiful of the orchids, found growing in sandy and rocky woods from
Newfoundland to North Carolina, and westward from Minnesota to Kentucky. The
crimson pink flowers are solitary at the summit of long scapes; the lip is large inflated,
slipper-shaped, drooping and with a fissure in front instead of a circular opening as in the
other species. — After Troth.

leaves for some distance back on the stem. The flowers are yel-
lowish-green and the segments of the perianth are similar, and
erect or spreading. The lip is united with the column, forming a

CLASSIFICATION OF ANGIOSPERMS. 499

FIG. 276. Round-leaved Orchis (Habenaria orbiculata) , an interesting orchid found
growing in rich deep woods in the north temperate regions of the United States. It has a
leafless scape, at the base of which are two orbicular or elliptical leaves spreading flat on the
ground. The flowers are in a loose raceme, greenish-white, the lip being oblong linear and
about the same length as the spur. — After Troth.

A TEXT-BOOK

BOTANY.

FIG. 277. White Fringed Orchis (Habenana blephariglottis), an attractive and rather
common orchid growing in bogs and peaty lands throughout the eastern and centra! United
States. The stems are from 4 to 6 dm. in length, terminated by many-flowered spike. The
flowers are white, the lip being copiously fiinged and the spur about 2 cm. in length. — After
Troth.

cylindrical body which is strongly concave on one side and spread-
ing at the upper portion. The pollinia are granular. Pollination

CLASSIFICATION OF ANGIOSPERMS. 501

may be effected by insects, but is usually brought about by arti-
ficial means (hand-pollination) . The fruits require several months
to become fully grown, and an equal period of time is necessary
for their maturity, which is indicated by their yellow color. They
are then gathered and cured by alternately steaming and drying
them, until they acquire the dark brown color and the odor of the
commercial article. Vanilla is cultivated in all tropical countries
where the temperature does not fall below 18° C, and the humidity
is considerable. Usually vanilla culture is combined with that of
Cacao. The plants begin to yield fruits the third year and continue
bearing for thirty or forty years (Fig. 274).

The yellow-flowering Cypripediums of the United States (C.
parviflonnn and C. parvifloruni pubescent) yield the cypripedium
which was formerly official. The plants are a foot or two high.
The leaves are oval or elliptical (in the latter) or elliptical or
lanceolate (C. parvifloruwi} . In C, pubescens the lip is pale yellow
with purple veins, 25 to 50 millimeters long, and possesses a tuft of
white, jointed hairs at the throat. In C. parviflorum the lip is
smaller and non-hairy. C. acaule is shown in Fig. 275.

The root-stocks of a number of Orchids are rich in mucilage
and yield the drug salep or a product resembling it. Salep occurs
in the form of globular or somewhat flattened, more or less trans-
lucent, light yellowish-brown tubers, 2 to 4 cm. long, of a horny
texture and a mucilaginous taste. The principal constituent is
mucilage, which originates in the cell-contents. It may contain
in addition either starch or sugar.

While the Orchidaceae, which contains about 6,000 species,
ranks second in numbers to the Composite, there is probably no
family which exceeds it in interest. The plants are extensively
cultivated, and some of their flowers are the highest priced known
in the commercial world. There are few localities in which there
are not some orchids to be found, illustrations of several of which
are here shown (Figs. 275 to 279).

B. CLASS DICOTYLEDONE^:.

The following are some of the prominent features of the
Dicotyledons: (i) The leaves are reticulately (open) veined and
usually with an irregular margin, being sometimes deeply lobed ;

502

A TEXT-BOOK OF BOTANY.

FIG. 278. Arethusa bulbosa, an Orchid growing in bogs from Newfoundland to South
Carolina, and west to Minnesota. It produces a solitary magenta-crimson flower on a long,
slender scape, in the sheaths of which a solitary linear leaf arises and protrudes after the
flower opens. In the illustration are shown a number of plants, some of which show the
.small bulbs at the base. — After Troth.

(2) the parts of the flower are usually in circles of 2 to 5 each;

(3) the stems and roots generally increase in thickness by means of
a cambium, and the vascular bundles are open, varying from

CLASSIFICATION OF ANGIOSPERMS.

FIG. 279. Rattlesnake Plantain, a rather common orchid, variously known as Epi-
Pactis, Peramium, or Goody era pubescens. It is generally found growing in coniferous woods
and characterized by the dark-green basal leaves with their prominent nerves and numerous
white reticulating veins. The flowers are greenish-white, numerous and crowded on the
erect scapes. — After Troth.

simple collateral to bi-collateral ; annular rings are formed in the
perennial stems; (4) the germinating plant usually has two coty-
ledons which are opposite each other. The Dicotyledons are
divided into two series or sub-classes, depending upon whether

504 A TEXT-BOOK OF BOTANY.

the parts of the corolla are distinct or are united, namely, the
Archichlamydeae and Metachlamydese.

ARCHICHLAMYDE^E OR CHORIPETAL^.

The Archichlamydeae or Choripetalse comprise those dicoty-
ledonous plants in which the petals are separate and distinct from
one another or are entirely wanting.

I. ORDER PIPERALES.

The plants of this order are mostly tropical herbs and shrubs
and possess very small flowers which have neither petals nor sepals.
The leaves are simple and without stipules, the most important
family medicinally, as well as in other ways, being the PIPERACE/E,
to which the following medicinal plants belong.

Piper nigrum is a woody climber that has leathery, grayish-
green, ovate-elliptical leaves (Figs. 281, 282), with three prominent
middle nerves and two side nerves; the flowers are perfect,
sessile and form an elongated fleshy spike ; the fruit is a berry
which is yellowish-red when ripe. The unripe fruit constitutes
the BLACK PEPPER of commerce. WHITE PEPPER is the ripe berry
of Piper nigrum from which the epicarp is removed, while " LONG
PEPPER " is obtained from Piper longum, an entirely different
plant, and consists of the entire spikes with immature fruits.

Piper Cubeba is a climbing perennial, with leathery elliptical-
ovate or long elliptical leaves ; the flowers are dioecious and
arranged in spikes ; the fruit is a berry, the pedicel becoming much
elongated after fertilization. The unripe fruit is the part used in
medicine and is official as cubeb.

Piper angustifolium yields MATICO, formerly official. The
plant is a shrub growing in Central and South America and is
characterized by its long, oblong-lanceolate, deeply reticulate, very
hairy leaves. The flowers and fruits are very small and arranged
in long, slender spikes, which are frequently found in the drug.
Matico contains 2 to 3 per cent, of a volatile oil, containing a
stearoptene matico camphor, which appears to be the most im-
portant constituent. It also contains an acrid resin, a bitter prin-
ciple, and a crystalline principle, artanthic acid. Other related

CLASSIFICATION OF ANGIOSPERMS.

505

-

•— «• \s?e*>ty& — I.---* v^=-^.

FIG. 280. Diagrams of cross sections of the flowers of a number of families of dicoty-
ledonous plants showing the number and position of the parts with reference to each other:
t, stem of plant; f, foliage leaf; b, bracts or leaves on the flower-stalk; s, sepals; p, petals;
a, stamens; c, ovary; per, perianth. A, Linaceae; B, Cruciferae; C, genus Citrus; D,
Rosaceae; E, Berberidaceae, showing nectaries (k) on the petals; F, Lauraceae, showing
staminodes (g); G, epigynous flower of Rubiaceae; H, Ericaceae; I, Labiatae, showing
position of other flowers (sv) in the cymes; J, Violaceae showing spurred stamens; K,
Campanulaceae, showing bracts (a, /3) the relation of the sepals (1,2,3,4 and 5), and two pos-
terior hairy stamens; L, Leguminosae, showing the large posterior petal (p) known as the
vexillum or standard, the two lateral petals (v) situated under the standard known as alse
or wings, and the two anterior petals which are covered by the wings and part.ly cohering
to form a prow-shaped body called the carina or keel (k). — Adapted from Warming.

506

A TEXT-BOOK OF BOTANY.

FIG. 281. Black pepper (Piper nigrum), a climbing shrub growing in Botanic Gardens,
Port of Spain, Trinidad. The illustration shows the ovate-elliptical leaves, opposite which
are the fruiting spikes, which when ripe are of a yellowish-red color. The plant has been
introduced into many tropical countries and is not infrequently seen in botanic gardens
throughout the civilized world. — Reproduced by permission of The Philadelphia Commercial
Museum.

species of Piper are used in tropical America similarly to Piper
angnstifolium.

The leaves of a number of species of Piper (known as " betel

CLASSIFICATION OF ANGIOSPERMS. 507

5o8 A TEXT-BOOK OF BOTANY.

leaves ") are mixed with the Areca nut and lime and constitute
what is known as " BETEL," which compound is used for chewing,
in India and other countries, chiefly on account of its astringency.
The root of Piper methysticum is also chewed, and when mixed
with the milk of the Cocoanut yields an intoxicating drink which
is used by the inhabitants of the Sandwich Islands. The dried
root has been used in medicine under the name of METHYSTICUM
or KAVA-KAVA. It consists of large, branching, soft, spongy,
dark brown pieces, which are tough, fibrous, and with a pungent,
somewhat bitter taste. Kava-kava contains 3 resins, one of which
has marked anaesthetic properties ; an alkaloid, kavaine ; a neutral
body, methysticin ; and about 50 per cent, of starch. The drug is
free from calcium oxalate crystals, these being usually wanting
in the Piperacese.

•y>f ";"'

II. ORDER SALICALES.

This order comprises but a single family, namely, the SALI-
CACEJE or Willow Family, to which belong the willows and pop-
lars. The plants are dioecious shrubs and trees ; the flowers being
in aments or catkins and without petals or sepals. The fruit is a
capsule containing many seeds which are small and with long, silky
hairs at the base.

The barks of a number of the members of this group contain
glucosides, as salicin, which is found in Salix alba, the white willow
of Europe and the United States, and the brittle willow Salix fra-
gilis; and populin, which is found in the white or silver-leaf poplar
(Populus alba) of Europe, Asia, and the United States and
Populus pyramidalis of Italy. These principles are also found in
other species of willow and poplar. A number of the barks con-
tain a yellow coloring principle allied to quercitrin, as Salix daph-
noides of Europe and Salix alba. Tannin is a common constituent
in both the willows and poplars. The buds of many of the poplars
contain in addition a volatile oil which is in the nature of a di-
terpene, as those of Populus pyramidalis. Populus balsamifera,
the tacamahac or balsam poplar of the United States and Canada,
furnishes the BALM OF GILEAD buds which are coated with an
oleo-resin that gives them their aromatic properties. Populus

CLASSIFICATION OF ANGIOSPERMS. 509

nigra yields a volatile oil, of which the important constituent is
humulene.

The charcoal used medicinally is prepared by burning the wood
of the young shoots of the white and black willow, poplar, beech,
or linden without access of air.

III. ORDER MYRICALES.

This group somewhat resembles the Salicales in that the flowers
are in aments. The flowers are either pistillate or staminate,
and mostly dioecious in our native species. The most important
family is the MYRICACE^E or Bayberry Family. The genus Myrica
is especially characterized by the fact that the outer layer of the
drupe is waxy. This is particularly true of the following species :
Myrica cerifera, the wax myrtle of the sandy swamps of the United
States, contains a volatile oil. The fruit of sweet gale (M. Gale)
yields a volatile oil containing a camphor. The sweet fern ( Comp^
tonia peregrina) found in the United States yields a volatile oil
resembling that of cinnamon. The rhizome of this plant contains
also tannin and possibly gallic and benzoic acids.

IV. ORDER JUGLANDALES.

The plants are trees with alternate, pinnately-compound leaves.
The staminate flowers are in drooping aments, the pistillate being
solitary or several together. The flowers are monoecious and
have a more or less distinct perianth consisting of 3 to 6 lobes.
The fruit is a kind of drupe formed by the union of the torus
with the wall of the ovary. There is but one family in this order,
namely, the JUGLANDACE^E (Walnut family), which includes the
hickory (Hicoria) and walnut. The black walnut (Juglans
nigra) of the United States yields a valuable timber and an edible
nut; the white walnut or butternut (/. cinerea) of the United
States yields the butternuts which are edible, and a bark which has
medicinal properties and was formerly official under the name of
JUGLANS. It contains about 7 per cent, of a yellow, crystalline
acrid principle which is colored purple with alkalies ; 2 to 2.5 per
cent, of a crystalline resin; volatile oil, tannin, sugar, and a
fixed oil. The bark of the stems of the butternut tree is used in
dyeing. The ripe fruits are edible, as also* the green nuts when

510 A TEXT-BOOK OF BOTANY.

pickled. The sap of the tree contains a sugar. The wood, though
inferior to black walnut, is used in cabinet making.

/. regia, native of Persia and cultivated in various parts of
Europe and California, yields the edible ENGLISH WALNUT.

The following species of hickory yield edible nuts : The shell-
bark hickory (Hicoria ovata) ; the pecan (H. pecan) common
from Illinois southward; and western shell-bark hickory (H.
sulcata). The wood of these as well as H. glabra and other species
of hickory is used where strength and elasticity are required.

Coloring principles are found in the barks of a number of
species and are used for technical purposes. The following con-
tain yellow coloring principles : Hicoria ovata, H. sulcata, and
H. glabra (pig-nut hickory) ; green coloring principles are found
in H. tomentosa, and yellowish-brown principles in Juglans nigra,
J. cinerea, and /. regia.

The fatty oils from the cotyledons (kernels) of both hickory-
nuts and walnuts are articles of commerce, and they have been
used in medicine.

V. ORDER FAGALES.

The plants are trees or shrubs with alternate, petiolate, simple,
pinnately veined leaves. The flowers are in aments, monoecious,
and with a more or less distinct perianth. The fruit is a nut which
is subtended by the mature involucre (bur or cup) or samara,
the seeds being without endosperm (Fig. 283).

a. BETULACE^ OR BIRCH FAMILY.— The plants are
aromatic trees or shrubs and are represented in the United States
by such trees as hornbeam (Carpinus), ironwood (Ostrya), and
birch (Betula) ; and by such shrubs as the hazelnut (Corylus) and
alder (Alnus). The plants yield a volatile oil consisting largely
of methyl salicylate. The bark of the sweet birch {Betula lenta)
yields the oil of betula which is official and closely resembles the
oil of wintergreen. The bark of a number of plants of this family
yields tannin and yellow coloring principles. A number of species
of Betula yield a sweet sap, as B. lenta, and B. Bhojpattra of Rus-
sia. The nuts of some species are edible, as the filbert or hazelnut
of Europe (Corylus Avellana), the hazelnut of the Orient (C.
Colurna), the American hazelnut (C. americana).

CLASSIFICATION OF ANGIOSPERMS. 511

b. FAGACE^ OR BEECH FAMILY.— This family includes
some of our largest forest trees, these being rather characteristic
of temperate regions. They are all highly valued for their timber,
and yield other valuable products besides. One notable character-
istic is that all of the chestnuts and oaks and some of the beeches

FIG. 283. White oak (Quercus alba): A, characteristic, lobed leaf; B, young branch
showing pistillate (p) and staminate (s) flowers; C. hairy bracts of a staminate flower; D,
group of hairs from bract; E, stamen; F. pollen grains; G, cluster of pistillate flowers; H,
acorn with cupule; I, starch grains from acorn, which vary from 10 to 25 M long; J. trans-
verse section of bark showing cork (k). stone cells (st), bast fibers (b), crystal fibers (ca),
medullary rays (m), parenchyma (p) ; K, longitudinal section of bark showing end of bast
fiber (b) crystal fibers (ca) and parenchyma cells (t) containing tannin.

contain tannin in the wood, bark, and leaves. The oaks are further
notable in being prone to the attack of gall-producing insects
(various species of Cynips) whereby the peculiar excrescences
known as galls are formed on the leaves and young shoots. Among
the oaks which yield galls rich in tannin are the following : Quercus
infectoria of the Mediterranean, which yields the official Turkish

512 A TEXT-BOOK OF BOTANY.

or Aleppo galls (pp. 206, 334) ; Quercus Robur, which is some-
times divided into Q. pubescens and Q. pedunculata, yields
a European gall; the live oak (Q. virginiana) of Texas; and
Q. lobata of California. Various oaks of the Southern States also
produce "ink balls " or " ink galls," as Q. cocclnea and Q. imbri-
caria. Several species of oak are used in the tanning industry,
as that of white oak (Quercus alba}, red oak (Q. rubra), Spanish
oak (Q. digitata), and black oak (Q. velutina), all of North
America; Q. pedunculata and sessiliflora of Germany, and Q. den-
tata of Japan.

The glucosidal coloring principle quercitrin is found in the
bark of Quercitron or black oak (Q. velutina}. Q. coccifera of
Southern Europe yields a red coloring principle which is used in
dyeing.

The wood of the American beech (Fagus americana) and of
the European red beech (F. sylvatica) yields a tar from which
on distillation the official CREOSOTE is obtained.

The cork of commerce which is used for a variety. of purposes
is derived from the bark of several species of Quercus, namely,
Q. Suber and Q. occidentals, growing in Spain, Southern France,
and Algiers.

The cotyledons of the seeds of the Beech family are rich in
proteins, starch, and oil, and some of the nuts are edible, as the
Spanish CHESTNUTS obtained from Castanea vulgaris, American
chestnut from C. dentata, and CHINQUAPIN from C. puniila (Fig.
202). .

VI. ORDER URTICALES.

This order embraces three families which, while they agree in
certain characters, are quite distinct in other ways.

a. ULMACE^ OR ELM FAMILY.— The plants are trees
or shrubs with alternate, simple, serrate, petiolate leaves. The
flowers are monoecious or dioecious, with a 4- to 6-divided peri-
anth. The fruit is a i-seeded drupe, samara, or nut. The typical
group of this family is that of the elms, of which the American
or white elm (Ulmus americana) is the most prized for orna-
mental purposes. The elms yield valuable timber, and the bark of
Ulmus campestris of Europe is used for tanning and dyeing be-
cause of the presence of tannin and a yellow coloring principle.

CLASSIFICATION OF ANGIOSPERMS.

513

The inner bark of the red or slippery elm (Ulmus fulva) is
used in medicine on account of its mucilaginous character (see
Fig. 119, C). The tree has a gray, fragrant bark; leaves which
are very rough above and become fragrant on drying, and the
wood is reddish-brown. The samara is not hairy as in some of
the other species.

FIG. 284. View taken in Ceylon of a part of a grove of 4-year-old rubber trees (Ficus
elastica). This tree is extensively cultivated in Ceylon and other portions of tropical Asia,
and most all of the Asiatic rubber is produced by this tree. The trees may be tapped when
25 years old, and for 50 succeeding years yield 40 pounds caoutchouc every 3 years. —
Reproduced by permission of The Philadelphia Commercial Museum.

b. HORACES OR MULBERRY FAMILY.— The mem-
bers of this family are herbs, shrubs, or trees, many of them con-
taining a milk-juice or latex. There are many representatives in
the tropical regions and some in temperate regions. The flowers
are unisexual, with a 4- to 5-parted perianth, and occur in spikes
or ament-like clusters.

Cannabis sativa. — This is the plant yielding hemp and also the
33

514

A TEXT-BOOK OF BOTANY.

drug Cannabis indica. The plant is an annual branching herb
from i to 3 M. high. The leaves are alternate above, opposite
below, digitate with 5 to 1 1 linear-lanceolate, deeply serrate lobes.
The flowers are dioecious, the staminate occurring in panicles and
the pistillate in erect simple spikes (Figs. 409, 410, 412). From
the inner bark of the stem, which is fibrous, the HEMP FIBER is
prepared.

FIG. 285. Several large rubber trees (Ficus elastica) growing in Java and showing
the production of numerous aerial roots from the branches. It occurs in damp forests
from the base of the Sikkim Himalaya eastward to Assam and Arracan. There are large
government plantations in Assam, and it is also being cultivated in other provinces. Kurz
remarks that it is frequent in Upper Burma, and that whole forests of the species are said
to exist in the valley of Hookhoom. — Reproduced by permission of The Philadelphia Com-
mercial Museum.

Humulus Lupulus or hop is a twining perennial plant, curving
to the right, with opposite, palmately 3- to 7-lobed (or simply
dentate above) rough leaves (Fig. 286). The flowers are dioecious,
the staminate ones occurring in panicles and the pistillate in
ament-like spikes. On the inner surface of each scale of the
ament occur two flowers consisting of a membranous perianth

CLASSIFICATION OF ANGIOSPERMS.

515

and a bicarpellary ovary with two long styles. After fertilization
the aments become cone-like, and this compound fruit constitutes
the hop of commerce. This fruit differs essentially from the
true strobiles or cones of the Gymnosperms in that the seed in
the latter is replaced by an akene. " Hops " are extensively used

FIG. 286. Hop vine (Humulus Lupulus): A, portion of branch with pistillate flowers
(f) and cone-like fruit (s) ; B, portion of rachis of strobile with two scales enclosing akenes;
C, pistil; D, hair from rachis; E, epidermis of scale; F, longitudinal section of akene show-
ing coiled embryo; G, surface view of bract showing epidermis and cells containing calcium
oxalate; H, cystolith of leaf; I, cystolith of stem; J, glandular hairs (lupulin).

in the manufacture of various beers and to a limited extent in
medicine.

Ficus Carica, which yields the edible fig, is a deciduous tree
from 3 to 7 M. high, and with large, 5-lobed, petiolate leaves.
The flowers are situated in a hollow torus the walls of which

Si6 A TEXT-BOOK OF BOTANY.

after fertilization become thick and fleshy, constituting the fruit.
The best figs come from Turkey, Italy, Spain, and Provence.

A large number of the plants belonging to the Moraceae yield
economic products, some of which, as the drug Cannabis indica
obtained from Cannabis sativa, are powerful narcotics. HASH-
ISH or BHANG is a preparation made from the dried leaves, stems,
and flowers of the pistillate plants and is smoked either alone or
with tobacco, or chewed in combination with other substances, or
an intoxicating drink is made from it, it being extensively used
by the inhabitants of Arabia, Persia, India, and other Oriental
countries. The leaves of Ficus Ribes of the Philippine and Mo-
lucca Islands are smoked like opium. The milk- juice of a number
of plants belonging to the Moracese is the source of arrow poisons.
The URARI POISON of Brazil is obtained from Ficus atrox ; the
IPOH ARROW POISON of Java and Borneo is derived from the Upas-
tree, Antiaris toxicara. Many of the plants of the group contain
emetic principles, as the COCILLANA BARK of Guarea Rusbyi, a
tree of Bolivia.

The milk- juice of quite a number of species of Ficus yields
India-rubber or caoutchouc (Fig. 128) , as Ficus elastica of the East
Indies, F. toxicaria of South America, F. clliptica and 'F. prinoides
of New Granada and several other species of Brazil, Brosimum
spurium of Jamaica, Cecropia peltata of the West Indies and
South America, and Castilloa elastica of Mexico and the West
Indies. Ficus benghalensis of India and tropical Africa, and
Ficus Tsiela of India, yield gum-lac. Ficus altissima and F.
religiose of tropical Asia yield shellac on the puncture of the stems
by a hemipterous insect (Coccus lacca).

A yellow coloring principle is found in Cudrania javanensis
of tropical Asia and Africa, Chlorophora tinctoria of Mexico,
Madura aurantiaca (Toxylon pomiferum) or osage orange, a
hedge plant of North America; Ficus tinctoria of the Friendly
Islands and F. asperrima of India. A fixed oil is obtained from
Artocarpus Blumei of Java.

A large number of the plants of the Moracese yield edible
fruits besides the fig tree already described, as the BREAD-FRUIT
trees (Artocarpus incisa) of the Sunda Islands and the JACK-TREE

CLASSIFICATION OF ANGIOSPERMS. 517

(A. integri folia) of the East Indies, the WHITE MULBERRY (Morus
alba) and the BLACK MULBERRY (Morus nigra).

The leaves of the white mulberry (Morus alba), indigenous,
to China and cultivated since the twelfth century in Europe and
now in cultivation to a limited extent in the United States, are
the chief food of the silkworm.

c. FAMILY URTICACE^E.— The plants belonging to the
Urticacese or Nettle family are chiefly herbs with mostly petiolate,
stipulate, simple leaves. The flowers are small and with 2 to 5
distinct or more or less united sepals. The fruit is an achene ;
the embryo is straight and surrounded by an oily endosperm. The
stems and leaves of several of the genera are characterized by
stinging hairs, this being especially true of the sub-group to which
the genus Urtica or stinging nettle belongs. Of the stinging
nettles the following are used in medicine : Urtica dioica of
Europe and naturalized in the United States, U. spatulata of
Timor, Laportea crenulata of tropical Asia, L. moroides of
Queensland, and Girardinia palmata of India. In the small
nettle (Urtica urens) of Europe and the United States an alka-
loid has been found, and Laportea stimulans has been used as a
fish poison. Boehmeria cor data of Brazil is used as a substitute
for Arnica. The fibers of a number of the Urticacese have been
found useful, of which the following may be mentioned : Urtica
cannabina of Asia, U. dioica, U. urens and Boehmeria nivea of
the Sunda Islands and China, the latter of which yields RAMIE.
The akene of Debregeasia edulis of Japan and the rhizome of
Pouzolzia tuberosa of China and Japan are edible.

VII. ORDER PROTEALES.

The members of this group are mostly shrubs and found prin-
cipally in the Tropics and southern hemisphere, several species
being cultivated in greenhouses for the sake of the beautifully
colored flowers which are in crowded inflorescences. The order
is represented by but a single family, namely, the Proteacese.
The leaves are leathery and vary even on the same plant from sim-
ple to compound. The glucoside proteacin and a bitter principle
are found in Leucadendron argenteum and L. continuum, both

518 A TEXT-BOOK OF BOTANY.

of Africa. A gum-resin is found in Grevillea robusta of Aus-
tralia, and a tannin in the bark of Lomatia obliqua of Chile.

A golden-yellow coloring principle is obtained from the flowers
of Persoonia saccata of Australia. The wood of Protea grandi-
flora of Abyssinia is used in wagon building, and Leucospermum
conocarpum of Cape Colony yields a valuable red wood and a
tan bark.

Banskia (cmula of Australia and the sugar-bush (Protea melli-
fera) of Australia and P. speciosa have a sugary cell-sap. The
oily seeds of the Chilean hazelnut (Guevina Avellana) are highly
prized as food by the inhabitants. The seeds of Brabeium stellati-
folium or wild chestnut of Cape Colony are poisonous when fresh,
but on roasting they become edible and are used as a substitute
for coffee.

VIII. ORDER SANTALALES.

This order embraces a number of families which are quite
distinct in several respects.

a. LORANTHACE^E OR MISTLETOE FAMILY.— The
plants are half-parasites with well-developed leaves containing
chloroplastids. They live on trees by means of haustoria. To
this family belongs the American mistletoe (Phoradendron fla-
vescem), parasitic on oaks, elms, the tupelo (Nyssa), red maple
and other deciduous trees. The white, globose berries of this
plant are quite poisonous, as are also those of the European mistle-
toe (Viscum album) and the oak mistletoe of Southern Europe
(Loranthus europccus). Viscum album contains a volatile alka-
loid, VISCINE, a glucoside and a resinous principle. This sub-
stance serves to attach the seeds to the barks of trees, where they
germinate, and it is used in the manufacture of BIRD-LIME, which
owing to its viscid character is used to catch small birds.

b. SANTALACE^E OR SANDALWOOD FAMILY.—
The plants are chlorophyllous herbs or shrubs which are common
in warm countries, and many of which are parasitic on the roots of
other plants. A number of them contain volatile oils, as the wood
of various species of Santalum. The official oil of sandal is obtained
from the scented wood of the white sandalwood (Santalum album),
a small tree growing wild and also cultivated in India and the

CLASSIFICATION OF ANGIOSPERMS. 519

East Indian Archipelago. The wood from the East Indies is
known as Macassar sandalwood and yields 1.6 to 3 per cent, of
oil, while the Indian wood yields 3 to 5 per cent. The oil consists
of 90 to 98 per cent, of santalol. Fiji oil of santal is obtained from
S. Yasi; and Australian oil of santal from Fusanus acuminatus
and F. spicatus. The Chinese oil is obtained from Santalum
Freycinctianum and .9. Preisci.

c. FAMILY BALANOPHORACE.E.— The plants of this
group are indigenous to tropical and sub-tropical regions. They
are root-parasites and develop tuberous rhizomes and fleshy shoots
which are yellow and without foliage leaves. Balanophom elon-
gata of Java grows on the roots of Ficus and other plants, and
contains a large quantity of wax and resin. Sarcophyte sanguined
of Cape Colony, which lives on the roots of certain Acacias, con-
tains a principle with the odor o.f scatol. Cynomorium coccineum,
found in the countries bordering the Mediterranean, has a blood-
red, astringent sap. The torus of the flower of Langsdorffia hypo-
gcca of tropical America is edible. The plant is also rich in wax,
and in New Granada it is sold under the name of " Siejas " and
burnt like a candle.

IX. ORDER ARISTOLOCHIALES.

This order includes two families which are very different in
their general habits, a. The Ramesiaceae are parasitic herbs that
are almost devoid of chlorophyll. The reddish vegetative parts
penetrate into the tissues of the host, and from these arise almost
mushroom-like flowers which in the case of Rafflesia Arnoldii
of Sumatra are I M. in diameter, being probably the largest flowers
known. The plants of this family are rich in astringent substances.

b. ARISTOLOCHIACE^ OR BIRTHWORT FAMILY.
— The plants are non-parasitic herbs or shrubs, some of which are
twining. The leaves are simple and in many of the plants more
or less cordate and reniform. The flowers are perfect and the
perianth is 3- to 6-lobed. While the flowers of our native species
are rather small and insignificant, those of the tropical plants are
extremely curious, being generally of some striking color and
of various odd forms.

Aristolochia reticulata is one of the plants that furnishes the

520 A TEXT-BOOK OF BOTANY.

official drug serpentaria (see Vol. II). From a slender rhizome
with numerous hair-like roots arise one or more short, leafy
branches which are more or less simple, somewhat hairy, and bear
oblong-cordate, prominent-reticulate, hairy leaves (Fig. 287). The
flowers are borne on slender, scaly, basal branches ; the calyx tube
is purplish and curved like the letter " s," being enlarged around
the ovary and at its throat. The fruit is a capsule containing
numerous flat or concave seeds. An allied species, Aristolochia
Serpentaria, furnishes the drug Virginia snakeroot. It is a more
delicate plant, the leaves being ovate-lanceolate, acuminate; the
flowers are solitary, and in some cases cleistogamous. This species
is found growing in the United States, more especially east
of the Mississippi, while Aristolochia reticulata is found west
of the Mississippi from Arkansas to Texas. The plants of this
genus contain volatile oils, and in addition to the two species
mentioned 45 other species are used in medicine in various parts
of the world.

Asarum canadense (Canada snakeroot or wild ginger) is a
plant common in the Northern United States and Canada (Fig.
288). The long and slender rhizomes are used in medicine.
They are 5 to 15 cm. long, about 2 mm. thick, more or less bent
and curved, purplish-brown externally ; whitish internally ; the
bark is thick, wood with about 12 fibrovascular bundles, pith large ;
the odor is aromatic ; the taste pungent and bitter. The drug con-
tains 2 to 3 per cent, of a volatile oil containing a fragrant body,
asarol ; a pungent, fragrant resin ; a yellow coloring principle
which is colored dark green with ferric salts ; and starch. The
volatile oil obtained from A. europccum contains a principle (asa-
rone) which forms irritating vapors on heating.

X. ORDER POLYGON ALES.

This order is represented by a single family, the POLYGONACE^:
cr Buckwheat family. The plants are mostly herbs, but include
some twining vines and shrubs. The leaves are simple, mostly
entire, and characterized by having a stipulate appendage (ocrea)
which sheaths the stem. The flowers are small, perfect, and with
a 2- to 6-parted perianth. The fruit is a 3- to 4-angled akene. The
embryo is either straight or curved, and the endosperm is mealy.

CLASSIFICATION OF ANGIOSPERMS. 521

FIG. 287. Southern serpentaria (Aristolochia reticulata) showing the cordate, reticu-
lately-veined leaves, and the clusters of irregular flowers on the lower part of the stem.
—After Carson.

522

A TEXT-BOOK OF BOTANY.

RHeum officinale is the source of the " South China " rhubarb
from Szechwan, Kanzu, and Shensi. The plant is a perennial herb
resembling the garden rhubarb. The rhizome is vertical and
gives rise to a leafy branch terminated by the inflorescence, which
is a panicle. The leaves are large, with a sub-cylindrical petiole,

FIG. 288. Wild Ginger (Asarum canadense). A, showing habit of plant, consisting of
underground root-stock, the kidney-shaped leaves on long petioles, and the short peduncled,
bell-shaped flower which develops close to the ground; B, longitudinal section of flower,
and C, a transverse section of flower. — Bicknell, in Bulletin Torrey Bot. Club, Nov., 1897.

a cordate or orbicular lamina which is either entire or coarsely
and irregularly dentate. There are several nearly related species
which also yield the drug. Rheum pahnatum of Northern China
has leaves which are lobed or deeply incised, which character is
especially marked in the variety tanguticum. Rheum Rhaponti-
cum, which yields English rhubarb, has leaves which are heart-

CLASSIFICATION OF ANGIOSPERMS. 523

shaped at the base and with a more or less irregularly undulate
margin. All of these species are more or less common in culti-
vation in botanical gardens in Europe.

FIG. 289. Curled dock (Rumex crispus} showing two of the lower, long-petioled, oblong-
lanceolate and wavy-margined leaves, and a flowering branch, the upper leaves of which
are narrowly-oblong and short-petioled.

Rumex crispus or curled dock is a perennial herb growing in
fields and waste places in the United States and parts of Canada.

524

A TEXT-BOOK OF BOTANY.

FIG. 290. Field or sheep sorrel (Rumex acetosella) , a common weed containing a
sour juice and growing in open fields; i to 3 dm. high, having narrow-lanceolate or halberd-
shaped leaves, and somewhat reddish flowers in a panicled raceme. — After Brown.

The leaves are oblong-lanceolate, with an undulate margin and
rather long petiole. The flowers have a 6-parted, dark green
perianth, and are perfect or polygamo-dicecious. The fruit is a

CLASSIFICATION OF ANGIOSPERMS. 525

dark brown, cordate-winged, 3-angled akene. The dried root is
somewhat fusiform, reddish-brown, and with a bitter, astringent

FIG. 291. Polygonum pennsylvanicum (Fam. Polygonaceae), one of about 30 species
of knotweeds, being common in waste places, all herbaceous, and characterized by the leaves
having sheathing stipules. Typical of this group is P. pennsylvanicum, having lanceolate
leaves and short, erect terminal spikes with bright rose-colored flowers. — After Brown.

taste. It contains chrysophanic acid, tannin, calcium oxalate, and
some of the other constituents found in rhubarb (Fig. 289).

Rumex Acetosella (field or sheep sorrel), is a slender annual
herb with hastate leaves, having flowers in compound racemes.

526

A TEXT-BOOK OF BOTANY.

The leaves contain oxalic acid, both free and in combination with
calcium and potassium (Fig. 290).

FIG. 292. Buckwheat (Fagopyrum esculentuni): A, transverse section of grain showing
pericarp (c), endosperm (n) and slender coiled embryo (e); B, transverse section of portion
of grain showing epicarp (e), fibrous layer (f), pigment layer (p), outer epidermis of spermo-
derm (o), aleurone cells (a), endosperm cells containing starch (n) ; C , surf ace view of cells
of epicarp; D, isolated fibers of pericarp; E. surface view of aleurone cells; F, isolated par-
enchyma cells of endosperm filled with starch grains as seen in buckwheat flour; G, appear-
ance of starch grains when mounted in oil and viewed with polarized light; H, swollen and
altered starch grains which are two to three times the size of the normal grains.

Tannin is obtained from a number of the plants belonging to
the Polygonacese, as the root of Rumex hymenosepalus of Texas

CLASSIFICATION OF ANGIOSPERMS. 5*7

which is known as CANAIGRE; the rhizome of Polygonum bistorta
of Europe which yields the drug BISTORTA.

Polygonum cuspidatum of the gardens contains emodin ; poly-
gonin, a glucoside yielding emodin ; and probably emodin methyl
ether. Rumex ecklonianus of South Africa contains emodm, a
volatile oil and a resin. The latter consists of emodin monomethyl
ether; chrysophanic acid, physosterol (resembling rhamnol), etc.
Polygonum Hydropiper and P. aviculare, both common in the
United States, are poisonous to sheep.

A number of the plants of this family yield food products.
Buckwheat is the fruit of Fagopyrum csculentum indigenous to
Central Asia and cultivated in many parts of the world (Fig. 292).

Some are also cultivated as ornamental plants, as the Prince's
feather (Polygonum orientale).

XI. ORDER CHENOPODIALES OR CENTROSPERM^.

This order includes seven families, in all of which the embryo
is curved or coiled, and the reserve consists chiefly of perisperm.

a. CHENOPODIACE^E OR GOOSEFOOT FAMILY.-
The plants are annual or perennial herbs with simple leaves and
small perfect flowers, the fruit being a utricle. The fruits of a
number of the group contain volatile oil, and are used in medi-
cine, as the common woTmseed (Chenopodiuin ambrosioides
anthelminticum) , which is found in waste places in the United
States. Most of the oil is distilled in Maryland and is known in
commerce as " Baltimore oil."

Che no podium mejcicanum yields saponin. Atriplex hortensis
of Tartary yields indigo. The ash of very many species of Atriplex
as well as genera of the Chenopodiacese yields soda. The seeds
of several species are edible, as of Chenopodium viride of Europe
and Asia, C. Quinoa of Chile, etc. Seeds of Spinacia tetandra
of the Orient are used in bread-making.

A number of species are used as garden vegetables, as spinach
(Spinacia oleracea) and beet (Beta vulgaris).

The SUGAR BEET (Beta vulgaris Rapa), which contains from
4 to 15 per cent, of cane sugar (sucrose), is largely cultivated in
Germany, as well as to some extent in the United States, and is
an important source of cane sugar. While the juice of the beet

528 A TEXT-BOOK OF BOTANY.

contains a larger amount of nitrogenous substances than that of
the sugar cane, it is practically free from invert sugar.

b. AMARANTACE^E.— The plants are weed-like and much
resemble the Chenopodiacese. They yield anthelmintic principles,
edible seeds, and the leaves of a number of species are used as
vegetables. The ash yielded by some species contains potash, as
Achyranthes aspera and Amaranthus ruber. Some are ornamental
plants having a fasciated inflorescence, as the Cock's-comb
(Celosia cristata).

c. NYCTAGINACE^E OR FOUR-O'CLOCK FAMILY .-
The plants are mostly herbs growing in America. The leaves are
entire and simple, and the flowers are regular and in terminal or
axillary clusters. The perianth consists of a 4- to 5-lobed corolla-
like calyx. The most common representative of this family is the
Marvel-of-Peru or four-o'clock (Mirabilis Jalapa). While this
plant is an annual in the United States, in the Tropics the tuberous
root is used as a substitute for jalap, and is sometimes sold for it.
The seeds of this plant are edible, as are also the leaves of several
species, as of Bocrhavia erecta, which are used as green vegetables.
Some members of the group, as Bougainvillea spectabilis, are
handsome plants with bright rose-colored bracts which envelop
the small greenish flowers.

d. PHYTOLACCACE^E.— The plants of this family are
mostly tropical and are represented in this region by only one
species, namely, the common poke (Phytolacca decandra), the root
and fruit of which are used to some extent in medicine. This is a
succulent, branching herb I to 4 M. high, having a large perennial
root. The stem is hollow except for the thin, papery partitions.
The leaves are simple, ovate-lanceolate, petiolate. The flowers
are in racemes and characterized by having ten stamens. The
fruit is a dark purple, juicy berry (Fig. 293).

The roots of this species as well as others contain powerful
drastic principles, as Pircunia littoralis and Anisomeria drastica
of Chile. Phytolacca abyssinica contains saponin, and a red color-
ing principle is found in the berries of Phytolacca decandra and
Rivinia tinctoria of Venezuela. The leaves of some species of
Phytolacca are used as greens.

e. AIZOACE^L. — This is a group of mostly tropical plants,

CLASSIFICATION OF ANGIOSPERMS. 529

FIG. 293. Poke weed (Phytolacca decandra), a common weed growing in low grounds
and waste places. The plant is a perennial herb, usually sending up from a large, fleshy
root a number of stout stalks, i to 3 M.'high; the leaves are ovate-oblong, and opposite which
may arise the racemes of whitish flowers. The roots are quite frequently mistaken for
parsnips, and when eaten may cause serious illness. The young shoots and leaves are
sometimes gathered in the spring and may be used for a table vegetable. The juice of the
berries is said to have been used in Portugal to color Port wine. — After Brown.

very many of them having fleshy leaves and adapted to arid re-
gions. Many of the plants, particularly those belonging to the
genus Mesembryanthemum, are much prized on account of their

34

530

A TEXT-BOOK OF BOTANY.

beautiful flowers, which expand only in the sunshine. The com-
mon ice-plant of the gardens, so called because of the numerous
glistening globules of water which cover the leaves, is M. crystal-

FiG. 294. Soapwort, Bouncing Bet (Saponaria officinalis), a perennial herb growing
to a height of 3 to 6 dm. and producing opposite, entire leaves, and cymose clusters of rose-
colored flowers, commonly double. This plant has been more or less cultivated; it has,
however, escaped from the garden, and, in spite of its beauty, has become a troublesome
weed in some places. The plant contains saponin and therefore forms a lather with water.
It has been used as a detergent. — After Brown.

linum. This plant as well as other species of Mesembryanthemum
are used in medicine. The ashes yielded by the plants of this
family also contain soda. The seeds of some species of Mesem-

CLASSIFICATION OF ANGIOSPERMS. 531

bryanthemum as well as other members of this family are edible,
and the leaves of some species are used as vegetables like lettuce.

/. PORTULACACEyE.— The plants are fleshy or succulent
herbs mostly indigenous to America. The two common represen-
tatives are the spring beauty (Claytonia virginica), the tubers of
which are rich in starch, and purslane (Portulaca oleracea), some-
times used as a green vegetable. The seeds of the latter plant as
well as of other species of Portulaca are used in medicine.

g. CARYOPHYLLACEyE. — The plants are annual or peren-
nial herbs, often swollen at the nodes, with opposite, entire leaves,
and usually perfect regular flowers. The perianth has a distinct
corolla of 4 or 5 petals. The fruit is a capsule and the seeds are
half anatropous. The plants are most abundant in the northern
hemisphere ; and some of them are quite showy, as the CARNATION
(Dianthus caryophyllus) and pinks (Dianthus species) and the
cultivated pink or Sweet William (D. barbatus). A number of
the members of this group contain saponin, as Bouncing Bet
(Saponaria offtcinalis) , which is naturalized in the United
States (Fig. 294), Gypsophila Struthium of Spain and other
species of this genus, as well as species of Lychnis and Her-
niaria. The leaves of Paronychia argentea are used in Morocco
as a substitute for tea. The roots of Scleranthus peren-
nis of Eastern Europe are inhabited by an insect (Coccus
polanica) which is used in the preparation of a red dye. The
fleshy stitch- wort (Alsine crassifolia) of Europe and the United
States is poisonous to horses.

XII. ORDER RANALES.

The plants are mostly herbs, but include some shrubs and trees,
and comprise eight families of economic importance.

a. NYMPH^ACE^: OR WATER LILY FAMILY.—
These are aquatic perennial herbs with thick root-stocks and
floating, peltate leaves. The flowers are perfect and have large
petals. The seeds are enclosed in an aril, and the embryo has fleshy
cotyledons.

Nuphar luteum of Europe and Middle Asia contains the alka-
loid nupharine and tannin, the latter of which splits into ellagic
and gallic acids. The yellow pond lily (Nymphoca advena) of the

532 A TEXT-BOOK OF BOTANY.

United States contains similar principles. The seeds and rhizomes
are rich in starch and are used as food, in some cases starch being
manufactured from them, as of various species of Nymphcca,
Nelumbo (Lotus) and Victoria, and Euryale ferox.

b. RANUNCULACE^ OR CROWFOOT FAMILY.—
These are annual or perennial herbs with simple or compound
leaves, regular or irregular flowers, and fruits which are akenes,
follicles, or berries.

FIG. 295. Fruiting top of Golden Seal (Hydrastis canadensis), showing the two large
palmate leaves, above one of which is a berry-like fruit which is bright red when ripe.

Hydrastis canadensis yields the official drug hydrastis. From
a short, thick, horizontal rhizome with numerous slender roots
rises a short stalk with a few palmately lobed, reniform, petiolate,
pubescent leaves. The flowers are small, solitary and greenish-
white, and the fruit is a head of crimson berries somewhat resem-
bling the raspberry (Fig. 295).

Cimicifuga racemosa (black cohosh or black snakeroot) yields
the official drug cimicifuga. This is a tall perennial herb with large
knotty rhizome, large decompound leaves, and a long raceme of
white flowers (Fig. 296).

CLASSIFICATION OF ANGIOSPERMS.

533

FIG. 296. A group of transplanted wild plants with a plant of Ctmicifuga racemosa
in the foreground, showing the characteristic, large, decompound leaves and long raceme of
flowers.

Aconitum Napellus yields the official drug aconite (Fig. 186).
This is a perennial herbaceous plant indigenous to Europe and
extensively cultivated. From a tuberous root arises a simple leafy

534

A TEXT-BOOK OF BOTANY.

stem with palmately lobed or divided leaves, and large, irregular,
blue flowers which form a rather loose panicle (Fig. 297). The
sepals are 5 in number, the posterior upper one being large and

E

FIG. 297. Acomtum Napellus . A, one of the long-petiolate, divided leaves; B, epi-
dermal cells of lower surface; c, an epidermal cell of the upper surface; D, transverse sec-
tion through one of the principal veins showing two fibrovascular bundles, and strongly
collenchymatic cells beneath the lower epidermis; E, one of the few hairs from the petiole;
F, lignified bast fibers surrounding the sieve in the petiole; G, longitudinal section through
fibrovascular bundle showing spiral and reticulate tracheae (t), bast fibers (b) and some
of the collenchyma cells (c), those at the left exhibiting longitudinal pores which give
a crystal-like effect.

helmet-shaped. The petals are 2 to 5 and rather small ; the two
posterior or upper ones which are hooded and concealed in the
helmet-shaped sepal are nectar-secreting (Fig. 223, E). The fruit
is a follicle and contains numerous small seeds.

CLASSIFICATION OF ANGIOSPERMS. 535

FIG. 298. Wood anemone, wind flower (Anemone quinque folia) , one of the earliest
flowering woodland plants. It is a low, slender plant with 3 trifoliate leaves forming an
involucre, from the junction of which arises a peduncle, bearing a solitary flower. The
sepals vary in number as well as in color; there are generally 5, which are usually whitish,
or slightly tinged with purple. — After Brown.

Delphinium Staphisagria, which yields the official staphisagria
or stavesacre, is a handsome, tall, biennial larkspur, with dark
green, palmate 5- or 7-lobed leaves and blue or purplish flowers in

536

A TEXT-BOOK OF BOTANY.

FIG. 299. Wild Columbine (Aquilegia canadensis), one of the most interesting plants
of the Ranunculaceae. It grows in the crevices of rocks and in open woods, and is a very
striking plant, with its 5 long-spurred, scarlet petals. A number of species of Aquilegia
are cultivated, and their flowers show considerable variation in form and color. — After
Brown.

racemes. The flowers are zygomorphic and somewhat resemble
those of Aconite.

CLASSIFICATION OF ANGIOSPERMS. 537

PULSATILLA, which was formerly official, is obtained from sev-
eral species of Anemone growing in Europe. These are perennial
herbs (Fig. 206) with basal leaves which are deeply lobed or
dissected, those of the stem forming a kind of involucre near the
flower. The flowers are rather large and with numerous petaloid
sepals. The fruit is a densely woolly achene in those species which
are used in medicine. The entire plant is used and contains an
acrid volatile oil, the principal constituent of which is an anemone
camphor (anemonol). The latter is easily decomposed into
anemonon, which on fusion becomes exceedingly acrid. Similar
principles are found in other species of Anemone as well as in
certain species of Ranunculus (buttercup) and Clematis Vitalba of
Europe.

Very many of the other Ranunculacese contain active princi-
ples. The glucoside helleborein, which resembles digitalin in its
medicinal properties, is found in Helleborus niger, the BLACK
HELLEBORE of Europe, and probably in other species of Helleborus,
as well as in Actcea spicata, the baneberry of Europe, and Adonis
vernalis, the false hellebore of Europe and Asia.

c. BERBERIDACE^: OR BARBERRY FAMILY.— The
plants of this family are herbs or shrubs with simple or compound
leaves, and flowers either single or in racemes (Figs. 134, E;
81, T). The fruit is a berry or capsule.

Herberts Aquifolimn (trailing mahonia) yields the unofficial
drug berberis. It is a low, trailing shrub with 3- to 7-compound,
scattered leaves. The leaflets vary from oval to nearly orbicular,
are obtuse at the apex, slightly cordate at the base, finely reticulate,
and spinose-dentate. The flowers are yellow and in dense ter-
minal racemes. The fruit is a blue or purplish berry.

Caulophyllum thalictroides or blue cohosh of the Eastern
United States is a perennial herb with a thick rhizome and large
ternately compound leaves (Fig. 300). The flowers are small
and greenish-purple. The fruit is peculiar in that it resembles a
berry and consists only of blue, globular, naked seeds, the pericarp
being ruptured and falling away soon after fertilization. The
rhizome and roots were formerly official. It is a horizontal, much
branched rhizome with broad, concave stem-scars, and numerous
roots ; it is grayish-brown externally, sweetish, slightly bitter and

538

A TEXT-BOOK OF BOTANY.

somewhat acrid. The drug contains an acrid, saponin-like gluco-
side, leontin ; a crystalline alkaloid, caulophylline ; two resins ; and
starch. For analysis of the seeds see Chem. News, 1908, p. 180.

Podophyllum peltatum or May apple is the source of the official
podophyllum. This is an early, herbaceous, low, perennial plant
forming large patches by reason of its long dichotomously branch-

FIG. 300. A group of transplanted plants, showing in the upper portion
a fruiting plant of blue cohosh (Caulophyllum thalictroides') .

ing rhizome (Fig. 182). It forms two kinds of branches, one
bearing a single, peltate, 5- to 7-lobed leaf ; and another bearing
in the axil of two similar leaves a white flower which gives rise
to a large, yellowish, ovoid berry which is edible.

d. MENISPERMACE^: OR MOONSEED FAMILY.—
The plants are climbing or twining, herbaceous or woody vines
with simple, entire or lobed leaves and small, greenish-white dice-

CLASSIFICATION OF ANGIOSPERMS. 539

cious flowers. The fruit is a drupe and contains a characteristic
crescent-shaped seed.

Menispermum canadense or Canada moonseed yields the drug
menispermum which was formerly official. It grows in the North-
ern United States and Canada and is a high-climbing vine with
broadly ovate, cordate and 3- to 7-lobed leaves (Fig. 180). The
flowers are in panicles giving rise to a characteristic cluster of
bluish-black berries.

The rhizome occurs in pieces which are 5 to 7 dm. long and
2 to 5 mm. in diameter; externally it is longitudinally wrinkled,
of a yellowish-brown color and somewhat resembles Sarsaparilla.
In transverse section, however, it is very distinct (Fig. 194). The
drug has a bitter taste and contains a bitter alkaloid menispine,
berberine and starch. In addition it contains the alkaloid oxyacan-
thine which is also found in Berberis vulgaris of Europe and the
West Indies.

Jateorhiza palmata yields the official drug calumba (columbo).
The plant is a herbaceous climber somewhat resembling Meni-
spermum, the leaves being more decidedly lobed. The flowers
form long racemes.

Chondrodendron tomentosum, the source of the unofficial drug
pareira, is a high woody twiner. The leaves are large, petiolate,
broadly ovate or rounded, slightly cordate, and densely tomentose
on the lower surface.

Anamirta paniculata is a woody climber of the East Indies.
The fruits, known as fishberries or COCCULUS, are used as a fish
poison by the natives and contain the neutral principle picrotoxin.

Very many other plants of the Menispermaceae contain power-
ful toxic principles and are used as fish poisons and as antidotes
to snake poison. Several species of Abuta are used in the prepara-
tion of curare poison.

e. MAGNOLIACE^E OR MAGNOLIA FAMILY.— The
plants are mostly trees or shrubs and are represented in the
United States by the magnolias and tulip tree (Liriodendron
Tulipifera). The latter is a magnificent tree with characteristic
leaves (Fig. 204) and large, fragrant, orange-colored, tulip-like
flowers.

The plants of this family contain a variety of constituents.

540 A TEXT-BOOK OF BOTANY.

Ethereal oils containing anethol and resembling those of anise
are found in the fruit of Illicium anisatum (I. verum) or STAR
ANISE, a small evergreen tree growing in the mountains of South-
ern China. A volatile oil with a disagreeable odor is found in a
closely related species /. religiosum (Shikimi) of Japan. The
fruit of the latter plant is known as JAPANESE STAR ANISE and
contains in addition a poisonous neutral principle. The fruits of
both star anise (Illicium) and the Japanese star anise are made up
of 6 to S radially arranged follicles, which are dark brown, dehis-
cent on the upper (ventral) surface and each contains a single,
brown, shiny seed. Star anise has an odor and taste resembling
anise. Japanese star anise has a bitter taste and in addition is
brownish-black, very woody and strongly beaked.

Volatile oils are also found in the flowers of the various species
of Magnolia and in Michelia Champaca found in the Malay Archi-
pelago and cultivated in India and Brazil, and in M. nilagirica of
India, the latter being used in perfumery.

Winter's bark is derived from Drimys Winteri, a shrub of
South America. It occurs in quills which are from 5 to 10 mm.
thick; externally it is grayish-brown and covered with numerous
lichens ; the fracture is short, the broken surface being marked
by stone cells and resin canals; the odor is fragrant; taste aro-
matic, pungent and bitter. The drug contains a volatile oil which
consists essentially of a hydrocarbon known as winterin; it also
contains a resin.

A crystalline principle magnolin, a glucoside and a volatile oil
are found in Magnolia macro phylla (or cucumber-tree of the
Southern States) and M. tripetala or umbrella tree growing
southward from Pennsylvania. A bitter principle liriodendrin, a
volatile oil, an alkaloid, and a glucoside are found in the tulip
poplar or tulip tree.

The bitter and aromatic bark of Michelia montana of Java is
used like cascarilla (Euphorbiacese). A bitter resin is found in
the fruit of Talauma Plumieri of the Antilles.

A glucoside which dissolves the blood corpuscles is found in
Talauma macrocarpa of Mexico. A red coloring principle soluble
in water occurs in the leaves of Michelia Tsiampaca of Java. The
fruits of Schizandra propinqua of Nepal and Kadsura Rox-

CLASSIFICATION OF ANGIOSPERMS.

54i

burghiana of Japan contain considerable mucilage and are edible.
The latter plant is also used as a hair-restorer. From the ash of
Schizandra chincnsis of China and Japan sodium chloride is
obtained.

The flowers of Magnolia Juglans are used to flavor tea and the

FIG. 301. North American papaw (Asimina triloba): A, branch showing lateral
nodding flower and the large, pinnately- veined, entire leaves : B. section of the oblong,
3-seeded berry; C, D, seeds, the one in longitudinal section. — After Baillon.

leaves of Talauma ovata are used as a substitute for tea in Brazil.
/. ANONACE^ OR CUSTARD-APPLE FAMILY.—
These are shrubs or small trees chiefly inhabiting warm-temperate
and tropical regions. They yield very many economic products.
The fruit of Xylopia brasilensis is used as a substitute for cubeb.
Some yield fruits having an aroma similar to that of nutmeg, as

542

A TEXT-BOOK OF BOTANY.

Monocarpia Blancoi of Africa and Jamaica. The flowers of
Cananga odorata of tropical countries are used in the preparation
of a pomade from which the perfume YLANG-YLANG is made.
Ethereal oils are also found in other species, as Uncna ligularis
of Ambyona, the seeds of which are used in perfumery. The bark
of Popowia pisocarpa of Java contains an alkaloid.

FIG. 302. Nutmeg trees growing in Singapore. The trees are handsome, evergreen
shrubs, extensively cultivated in the East Indies, and to some extent in tropical America. —
Reproduced by permission of The Philadelphia Commercial Museum.

The seeds of Xylopia salicifolia of Trinidad and X. muricata of
Jamaica are very bitter, as are also the wood and bark of X. glabra
of the West Indies.

The seeds of Asimina triloba, the North American papaw
(Fig. 301), contains an emetic principle. This plant should not
be confounded with Carica Papaya (Caricacese) which contains
the ferment papain.

Many of the Anonacese yield large succulent fruits, some of
which are edible, as the sugar apple obtained from Anona squa-

CLASSIFICATION OF ANGIOSPERMS.

543

mosa and CUSTARD APPLE from A. reticulata both abundant in the
Tropics. The fruit of A. muricata sometimes weighs as much as
two kilograms.

g. MYRISTICACE^: OR NUTMEG FAMILY.— This
family is represented by the single genus Myristica. Nutmeg

FIG. 303. Young plant of Cinnamomum zeylanicum grown from cutting.

(Fig. 302) and mace are obtained from Myristica fragrans, an
evergreen tree with ovate, petiolate, coriaceous, entire and
pinnately-veined leaves. The flowers are small, yellow and dice-
cious. The fruit is a berry having somewhat the shape and size
of the green fruit of black walnut. It has a line of dehiscence,
and when ripe is yellow. The arillode of the seed constitutes MACE,

544 A TEXT-BOOK OF BOTANY.

while the kernel is th£ NUTMEG, the pericarp of the fruit and coat
of the seed being rejected.

h. LAURACE^: OR LAUREL FAMILY.— The members
of this family are chiefly shrubs and trees which are distributed
mostly in the Tropics, although a few are found in the temperate
zones (Fig. 280, F).

Sassafras officinale. — This is a tree common in the eastern and
central portion of the United States and is characterized by its
rough bark and its I- to 3-lobed leaves, from whence it received
its former name Sassafras variifolium (Fig. 203). The flowers
are yellow, dioecious and appear in the spring before the leaves.
The fruit is an oblong, blue drupe.

Cinnanwmum zeylanicum, which is the source of the Ceylon
cinnamon (Fig. 304), is a small, handsome, evergreen tree with
opposite, coriaceous, broadly lanceolate, 3- to 5~nerved leaves (Fig.
303). The flowers are yellowish- white, hermaphrodite, or both
pistillate and staminate. The fruit is a black, ovoid berry. The
oil of Ceylon cinnamon from the bark and branches is charac-
terized by its content of cinnamic aldehyde; from the leaves by
eugenol; and from the root bark by camphor. C. Cassia which
yields Cassia cinnamon is a tree growing in China, Sumatra, and
cultivated in Java. It has long, oblong-lanceolate leaves which are
pubescent on the lower surface. Cassia cinnamon (bark) is also
obtained from Cassia Burmanni. Saigon cinnamon (see Vol. II)
is derived apparently from wild trees growing in the mountainous
regions of Anam, the botanical origin of which has not been
determined.

The volatile oils of the members of the Lauraceae vary con-
siderably in composition. In addition to the oils of Sassafras
and Cinnamon the following may be mentioned : A CINNEOL-
containing oil is found in Cinnamomum Oliveri of Australia,
Umbellularia calif ornlca of Western North America and Laurus
nobilis the noble laurel of the Mediterranean and Mexico. A BOR-
NEOL-containing oil is obtained from the root of Dicypellium
caryophyllatum of Guiana, the wood of which is known in
Cayenne as rose-wood. An oil containing a notable amount of
METHYL SALICYLATE is obtained from the spice-bush (Lindera
Benzoin) of the United States.

CLASSIFICATION OF ANGIOSPERMS.

545

FIG. 304. Cutting cinnamon in Ceylon. Cinnamomum zeylanicum is a native of the
forests of Ceylon and is extensively cultivated, not only on the western coast of that island
but in other countries of tropical Asia. The manner of cultivation is such that a number of
stems are allowed to grow from a single root. When of sufficient height these are cut down
and the smaller branches removed, as shown in the illustration. The bark is then separated
from the thicker portion of the stems, gathered into bundles and placed under mats until
a slight fermentation takes place. After the corky layer is removed the product is ready
for the market. — Reproduced by permission of The Philadelphia Commercial Museum.

Cinnamomum Camphora, or the camphor tree, is indigenous to
China, Japan and Formosa, and is now cultivated in many warm
35

546 A TEXT-BOOK OF BOTANY.

countries as a shade and ornamental tree, growing very well in
Southern California and the Southeastern States. All parts of
the tree contain a volatile oil which on oxidation yields camphor,
which latter is obtained on distillation and sublimation. Camphor
of poor quality is obtained from C. Parthenoxylon of Burmah,
Malaya and China, and C. glandulifermn of the Himalayas. Cam-
phor is also a constituent of other ethereal oils of this same
family, as the Massoy bark oil obtained from the root bark of
C. zeylanicum and C. Burnianni of Java.

A EUGENOL-containing volatile oil is obtained from Ravensara
ar&matica of Madagascar, and Machilus Thunbergii of Japan.
Eugenol is also found in oil of laurel leaves (L. nobilis), Massoy
bark oil, the oil of the leaves of Ceylon cinnamon, and the oils
obtained from Cinnamomum Culilawan of the Malay Peninsula
and China, and C. Wightii of East India, and possibly is also
found in Dicypellium caryophyllatum.

The wood and the bark of Nectandra or Beeberu (Nectandra
Rodicei) of Guiana and Brazil contain several alkaloids, one of
which is known as beeberine and is supposed to be identical with
the alkaloids in Buxus sempervirens (Earn. Buxacese) ; pelosine
found in Pareira ; and paricine found in the bark of the cultivated
cinchonas of Java. Coto bark, which is used in medicine, is
obtained from an unknown tree in Northern Bolivia belonging to
this family. The bark contains a volatile oil having a pungent
taste, and a volatile alkaloid.

Fatty oils are obtained from Ravensara aromatica of Mada-
gascar, Litsea glauca of Japan and other species of Litsea found
growing in Cochin China and India. A red sap with a very fetid
odor is obtained from Ocotea fattens of tropical and sub-tropical
America, and the stink-wood of South Africa (0. bullata).

XIII. ORDER RHCEADALES OR PAPAVERALES.

These are mostly herbaceous, seldom woody, plants. The
flowers are perfect and the fruit capsular. This order includes
two families of importance medicinally.

a. PAPAVERACE^E OR POPPY FAMILY.— These are
herbs with a milky or colored latex.

Papaver somniferum or opium poppy is an annual herb I to 2

CLASSIFICATION OF ANGIOSPERMS.

547

M. high. The stem is sparingly branched, with alternate, deeply
lobed, pubescent, clasping (by a cordate base), dull green leaves
(Fig. 305, A). The flowers in the variety album, from which
opium is obtained, are white or silver-gray, and in many cultivated
varieties are large and extremely showy. The two sepals drop
away with the expansion of the corolla ; the ovary is smooth, more
or less globular and subtends the radiate stigma; the fruit is a

FIG. 305. A, Opium poppy (Papaver somniferum) ; B, California poppy (Eschs^holt-
zia calif arnica) showing flower (a), and capsules (b, c), one of which (c) is dehiscent. — After
Schimper.

capsule (Fig. 238), dehiscing by means of terminal pores, and
contains a large number of extremely small white seeds, known as
MAW-SEED, and which yield a fixed oil known as poppy-oil. The
latex of this plant (Figs. 306, 307) yields opium.

Other allied members of the Papaveraceae possess narcotic
properties, but the alkaloid morphine has not been isolated from
any of them, as the California poppy (Eschscholtzia calif orni ca )
(Fig. 305, B) ; the Mexican poppy (Argemone mexicand) ; Hy-
pe coum procumbent, and Fumaria plicata, both of Southern

548

A TEXT-BOOK OF BOTANY.

Europe. These latter plants probably contain also the alkaloid
protopine which is apparently identical with fumarine.

Sanguinaria canadensis or bloodroot, the rhizome of which is
official. The plant is a small, herbaceous, perennial herb with a red
latex. The rhizome is horizontal, short and thick, and gives rise
to a single, petiolate, palmately 5- to 9-lobed "leaf and a single
white flower with a long peduncle (Fig. 308). The capsule is

FlG. 306. Poppy fields in the meadows 8 miles northwest of Ping-li, Shensi, China,
showing the plants with large terminal flowers. — Reproduced by permission of The Phila-
delphia Commercial Museum.

oblong, 2-valved, and contains a number of smooth but crested
seeds.

Chelidonium ma jus (celandine) is the source of the herb
CHELIDONIUM which was formerly official. The plant is a delicate
branching herb about 0.5 M. high ; with alternate, deeply pinnati-
fid leaves ; yellow flowers ; slender elongated capsule resembling
that of the mustards, and a yellow latex in every part. Celandine
is indigenous to Europe and Asia and is common in waste places
in the United States. The drug contains the following alkaloids :

CLASSIFICATION OF ANGIOSPERMS.

549

FlG. 307. Poppy fields in Afionkarohissar, Turkish Empire. The capsules are ready
to be incised, allowing the milky juice to exude, which is then collected and constitutes the
opium of commerce. — Reproduced by permission of The Philadelphia Commercial Museum.

550 A TEXT-BOOK OF BOTANY.

Chelidonine (identical with stylophorine), chelerythrine (which
is fluorescent ), and protopine (found also in opium and sangui-
naria). It also contains a bitter neutral principle chelidoxanthin
and several organic acids (Fig. 309).

To this family belong a number of other plants which contain
principles similar to or identical with those found in Sanguinaria
and Chelidonium, and of these the following are common in the

FIG. 308. A group of transplanted bloodroot plants (Sanguinaria canadensis) show-
ing i-flowered scapes, and the palmately veined and lobed leaves.

United States : Yellow or celandine poppy (Stylo phorum diphyl-
lum) and the Dutchman's breeches (Bicuculla Cucullaria}.

The alkaloid PROTOPINE (fumarine) is found in the following
plants of this family : Sanguinaria canadensis; Chelidonium
majus; Stylo phorum diphyllum; Eschscholtzia calif ornica; Glau-
cium corniculatum of Middle Europe; Bicuculla Cucullaria; Ad-
lumia fungosa, the climbing fumitory of the United States and
Canada; Fumaria officinalis, the fumitory of Europe, which is
naturalized in the United States and Canada ; Bocconia cordata
of China and Japan, and B. frutescens of the West Indies, Mexico

CLASSIFICATION OF ANGIOSPERMS.

and Paraguay ; Dicentra pusilla of Japan and several species of
corydalis. The tubers of squirrel corn or corydalis (Bicuculla
canadensis) contain the alkaloidal corydaline.

FIG. 309. Celandine (Chelidonium majus), a biennial herb, with pinnately divided
leaves, and terminal clusters of small, yellow flowers. The plant has an orange-colored
latex. — After Brown.

b. CRUCIFER^: OR MUSTARD FAMILY.— These are
herbaceous plants with characteristic flowers and fruits. The
flowers have four deciduous sepals, four petals which are more or
less spreading and clawed at the base, and six stamens which are
tetradynamous (Fig. 280, B). The fruit is a 2-celled silique or

552

A TEXT-BOOK OF BOTANY.

FIG. 310. Fruiting specimens of the two mustards, the one on the left White Mustard
(Brassica alba), and the one on the right Black Mustard (Brassica nigra). — After Newcomb.

CLASSIFICATION OF ANGIOSPERMS. 553

silicic, which varies in shape in the different genera (Fig. 310).

Brassica alba (white mustard). — The plant is a slender,
branching, more or less hispid (bristly hairy) annual or biennial
herb usually less than 0.5 M. high, with deeply pinnatifid lower
leaves and lanceolate, dentate upper leaves. The flowers are
yellow, and the silique is densely hispid, constricted between the
seeds and terminated by a long, flat, sword-like beak (Fig. 310).
The seeds are official as white mustard (Sinapis alba) but are
known in commerce as yellow mustard.

Brassica nigra or black mustard, the seeds of which constitute
the official black mustard (Sinapis nigra), is a larger, more branch-
ing plant than Brassica alba, being from I to 3 M. high. The
silique is erect, more cylindrical and with a slender, filiform beak
(Fig. 310).

Glucosides similar to those which occur in BRASSICA ALBA and
BRASSICA NIGRA are also found in other species of BRASSICA,
as well as in the following related plants, but the oils produced
are not identical: Horseradish (Roripa Armoracia), the oil being
similar to volatile oil of mustard; water cress (R. Nasturtium) ;
garden radish (Raphanus sativus) ; Sisymbrium Alliaria of Eu-
rope, and the hedge mustard (S. officinale) naturalized in the United
States; TURNIP (Brassica Rapa) of Europe; field penny-cress
(Thlaspi arvense) of Asia and found in waste places in the
Eastern and Middle United States ; the narrow leaved pepper-
grass (Lepidium ruder ale) naturalized from Europe ; scurvy-grass
(Cochlearia officinalis) of Northern and Middle Europe, the herb
of which, known as HERBA COCHLEARIA, is used in medicine;
" HONESTY" (Lunaria annua) common in cultivation on account
of the ornamental use of the dry pods ; Parrya macrocarpa of
Southern Europe; treacle mustard (Erysimum cheiranthoides) of
Northern Europe and the United States, and garlic mustard (E.
Alliaria).

The seeds of most of the Cruciferae are also rich in fixed oils,
and the commercial oils are obtained from the following species :
Wild mustard or charlock (Brassica arvensis) naturalized in the
United States from Europe ; Hesperis tristis of Southern Europe ;
cabbage (Brassica oleracea). An INDIGO- forming glucoside is
found in Isatis tinctoria of Europe and /. indigotica of China;

554 A TEXT-BOOK OF BOTANY.

Neslia paniculata of Europe and the Orient ; and Lepidium owai-
hiense of the Hawaiian Islands. Shepherd's purse (Capsella
Bursa-pastoris) contains an alkaloid (bursine) and tannin. The
leaves and roots of many of the Cruciferse are used as garden
vegetables, and some are cultivated as ornamental plants. The
seeds of Lunaria biennis (or "ho-nesty") contain an orange-red
crystalline alkaloid, or possibly a mixture of alkaloids.

c. There are several other" families of the Rhoeadales which
yield economic products. The RESEDACE^E include the migno-
nette (Reseda odorata), the flowers of which yield a fragrant vola-
tile oil ; and R. Luteola of Europe, which contains a yellow coloring
principle and also an anthelmintic principle. The MORINGACE^
comprise a single genus, Moringa. The root of M. oleifera of
tropical and sub-tropical countries contains a volatile oil resem-
bling the volatile oil of mustard, and the stem yields an astringent
gum resembling that of Bombax malabaricum (Bombaceae).

XIV. ORDER SARRACENIALES.

This order includes several families which are of special inter-
est because of the fact that the leaves are of peculiar construction
and adapted to the catching and digestion of insects (Fig. 208).

Probably all of the plants of this order produce proteolytic
ferments resembling those in the pine-apple and are capable of
acting upon and digesting animal substance. Some writers have
supposed that the properties of these plants might be due to bac-
teria present in the liquid contained in the pitchers of the leaves,
but there seems to be no question that a distinct enzyme resem-
bling trypsin is formed in those plants which have been studied.

(a) The genus Sarracenia of the family SARRACENIACE^E or
pitcher-plant family, is represented in the United States by a
number of species. The rhizome of Sarracenia purpurea (Fig.
311) contains several alkaloids, one of which, sarracenine, seems
to have some resemblance to veratrine. (b) The DROSERACE^: or
sundew family includes the Droseras or sundew plants and Dioncea
muscipula, the Venus's flytrap o-f North Carolina (Fig. 209). A
number of species of Drosera contain a red coloring principle
similar to that isolated from the rhizomes of D. Whittakern of
Australia and is a derivative of methylnaphthoquinone. Citric

CLASSIFICATION OF ANGIOSPERMS.

555

FIG. 311. Pitcher Plant (Sarracenia pur pur ea). The plant grows in peat bogs, and
the pitcher-shaped leaves are usually half filled with water and serve as a trap for insects,
which are finally digested and furnish the plant with nitrogenous food. The flowers are
single on a naked scape and of a deep purple color, the petals being arched over the style.
Many species of Sarracenia are prized by horticulturists because of their odd trumpet-
shaped leaves. — After Troth.

acid has been found in D. longifolia, a sundew common in the
•United States as well as in Europe and Asia, (c) The family
•NEPENTHACE^E contains the single genus Nepenthes, several spe-

556 A TEXT-BOOK OF BOTANY.

cies of which are extensively cultivated in greenhouses. The
leaves and roots of N. Boschiana of Borneo contain an astringent
principle.

XV. ORDER ROSALES.

The plants range from herbs to shrubs and trees and have
complete flowers which are mostly perigynous. The carpels are
solitary, or several either distinct or united.

a. PODOSTEMACE^E OR RIVER-WEED FAMILY.—
/The plants are aquatic and more or less alga-like, and are repre-
sented in the United States by the river-weed (Podostemon Cerato-
phyllum), which is a densely tufted plant found in running water
attached to stones. The ash of these plants contains a consider-
able amount of sodium chloride, the ash of M our era Weddelliana
of Brazil containing 50 per cent, of salt and being used as a source
of table salt.

b. CRASSULACE^E OR ORPINE FAMILY.— The plants
are chiefly succulent herbs and represented by such plants as
houseleek (Sempervivum tectorum), which is cultivated largely
as an ornamental plant, and the common sedums, of which there
are numerous species in temperate regions. The common mossy
stonecrop or wall-pepper (Sedum acre} naturalized in the North-
ern United States contains a ferment capable of dissolving the
membrane formed in diphtheria and croup ; Sempervivum balsami-
ferum of the Canary Islands contains a substance resembling the
viscine found in certain Loranthacese. Ditch or Virginia stonecrop
(Penthorum sedoldes) contains tannin.

c. SAXIFRAGACE^E OR SAXIFRAGE FAMILY.— The
plants are mostly found in temperate regions and among the im-
portant members are mitrewort (Mitella), false mitrewort (Tia-
rella cordifolia), alum root (Heuchera americana}, golden saxi-
frage (Chrysosplenium) , grass of Parnassus (Parnassia), mock
orange (Philadelphus coronarius) and the wild hydrangea (Hy-
drangea arborescens).

The plants are rich in tannin, as the alum root of Eastern and
Central North America, which contains 10 to 20 per cent, of
tannin. A glucoside hydrangin, a volatile oil, and possibly also
a saponin are found in "SEVEN BARKS" or wild hydrangea (PL

CLASSIFICATION OF ANGIOSPERMS.

FIG. 312. Early Saxifrage (Saxifraga virginiensis), a perennial herb with a whorl of
root leaves from which arise the flower scapes bearing open and loosely panicled cymes.
It grows in the clefts of rocks, and the name is derived from the Latin, meaning to break
a rock. No doubt because of its habit, medicinal virtues were earlier ascribed to it, and it
was used to cure stone in the bladder. — After Troth.

arborescens) ; a glucoside is also found in the root of garden
hydrangea (H. paniculata grandiflora) .

In this family are also included the gooseberries (Fig. 245)

558 A TEXT-BOOK OF BOTANY.

and currants. The cultivated CURRANTS are varieties of Ribes
rubrum: the cultivated GOOSEBERRIES are varieties of R. Uva-
crispa. Both of these plants are natives of Europe and Asia and
have escaped from cultivation in the United States and Canada.
The fruits contain fruit-acids and fruit-sugars and are used in a
variety of ways. The fetid currant (Ribes prostratum) has a very
fetid odor and it is said that the flowers of the buffalo currant
(Ribes aureum) contain hydrocyanic acid.

e. HAMAMELIDACE^: OR WITCHHAZEL FAMILY.—
The plants are shrubs or trees and are most abundant in sub-
tropical countries.

Hamamelis. virginiana, or witchhazel, the leaves and bark
of which are used in medicine, is a shrub which is especially
characterized by its asymmetric, undulate leaves and by its produc-
ing flowers in the autumn when the leaves are falling and the
mature, but not ripe, capsules of the preceding year are still
present (Fig. 313).

The forked branches of the witchhazel, as also the twigs of
the peach and other plants, are used in various parts of the
United States for detecting the presence of underground water.
These are operated somewhat as follows : The branched arms
are held by the operator in a horizontal position and as the operator
surveys the field, it is supposed the main stem will dip in the
direction indicating either underground water, petroleum, etc. It
is the honest belief of the operators, that the working of the rod
is influenced by agencies — usually regarded as electrical currents
following underground springs of water — that are entirely inde-
pendent of their own bodies, and many uneducated people have
implicit faith in their ability to locate underground waters in this
way. However, it is held by scientists that the operation of the
divining rod is generally due to the unconscious movements of the
body or muscles of the hand.

Liquidambar styraciflua or sweet gum-tree of the Atlantic
coast of the United States and Mexico, is a tall tree with charac-
teristic cork-wings on the branches ; 3- to 7~lobed, petiolate, finely
serrate leaves ; monoecious flowers, and a spiny, globular, capsular
fruit. The tree yields a balsam allied to the official styrax

CLASSIFICATION OF ANGIOSPERMS.

559

(storax), which is obtained from a very similar tree (L.
orientalis).

f. PLATANACE^: OR PLANE TREE FAMILY.— This

FIG. 313. Branch of Witchhazel (Hamamelis virginiana) showing alternate, short-
petiolate and pinnate-reticulately veined leaves, having a broadly oval or obovate out-
line, round, acute, or slightly acuminate apex; slightly cordate, inequilateral base; and
undulate or sinuous margin.

/amily consists of but one genus, Platanus, of which there are
7 species. It includes the sycamore or buttonwood (Platanus
occidentalis}, one of our largest trees, easily recognized by its

A TEXT-BOOK OF BOTANY.

mottled exfoliating bark. The leaves are palmately lobed and
within the base of the petioles are formed the winter buds. The
flowers are staminate and pistillate heads, borne on separate ped-
uncles. The fruits are spherical heads about 2 cm. in diameter,
composed of numerous achenes, and persist on the trees throughout
the winter. The wood is not only used for building purposes, but
also for butchers' blocks.

FIG. 314. Cross- pollination through the agency of a bee, in flower of quince (Cy-
donia vuigaris). A, flowering branch; B, flower showing bee extracting nectar, and masses
of pollen adhering to its legs, some of which will fall upon the stigmas of other flowers when
it visits them; C, ripe inferior fleshy fruit (pome) of quince. — After Dodel-Port.

/. ROSACES OR ROSE FAMILY.— The plants are herbs,
shrubs or trees usually with alternate, stipulate, simple or com-
pound leaves, and regular perfect flowers with or without petals,
and numerous stamens (Fig. 280, D). The fruit is a pome (Fig.
314), drupe (Fig. 315), follicle or achene (Fig. 236).

Prunus serotina or wild black cherry is a tree varying from
10 to 30 M. in height, with a more or less smooth bark marked by
prominent transverse lenticels, and showing a tendency to peel
off in semicircular pieces, which gives the older bark, which is
more or less black, a roughened appearance. The leaves and inner

CLASSIFICATION OF ANGIOSPERMS. 561

bark have an agreeable aromatic odor; the leaves are oval- or
oblong-lanceolate, acute or acuminate, and serrate, the teeth being

.' FIG. 315. Fruiting branch of wild black cherry (Prunus serotina).

glandular ; the flowers are white and in racemes ; the fruit is a
dark purple or blackish, globular drupe (Fig. 315). The nearly
related species wild cherry or choke cherry (Prunus virginiana)
36

562 A TEXT-BOOK OF BOTANY.

is a shrub or small tree with broadly oval, acuminate leaves, red
or nearly black drupes, and flowers and fruits several weeks
earlier than P. serotina.

Prunus Amygdalus is a small tree resembling somewhat the
peach tree. The leaves, are lanceolate, serrate; the flowers are
rose-colored, and the fruit is a dehiscent drupe in which the
leathery sarcocarp separates from the endocarp, which latter, with
the seed which it encloses, constitutes the edible almond of the
market. The kernels of some of the seeds are quite bitter (bitter
almonds), and some are bland and free from bitterness. By a
process of selection plants yielding the latter are now extensively
cultivated in sub-tropical and warm-temperate regions, and yield
the sweet or Jordan almond of the market. In Turkestan some
of the almonds have a smooth endocarp.

A glucosidal substance having the properties of amygdalin is
found in the buds, leaves, bark and seeds, more especially the
latter, of some members of the following genera : Prunus, Sorbus
(mountain ash), Cotoneaster, Amelanchier, and Eriobotyra (E.
japonica or Japanese medlar).

Prunus domestica yields the French plum or prune of com-
merce. The leaves are ovate or ovate-lanceolate, dentate, and
pubescent on the lower surface. The flowers are greenish-white,
with a hairy peduncle. The fruit is a drupe, with a black or
bluish-black epicarp, a brownish sarcocarp, and a hard, oval,
smooth and flattened endocarp.

The endocarps of the members ol me genus Prunus vary greatly.
The endocarp in the apricot (P. Armeniaca) is quite smooth, as is
also that of the cherry (P. Cerasus) ; in the peach (Prunus Per-
sica) it is reticulate. The bark of Pyrus Toringo yields a yellow
coloring principle known in Japan as " dzaini." It also contains
a white, crystalline glucoside (toringin), and pyrus-quercitrin, the
latter forming yellow needles and on hydrolysis yields quercetin
and rhamnose. The bark is also used to adulterate licorice, gentian
and other drugs in the powdered form.

The apple (Pyrus Mains) , the pear (Pyrus communis) , and the
quince (Cydonia vulgaris) are inferior fruits known as pomes,
the fleshy part developing from the torus and persistent calyx,
the core being composed of the united carpels. The edible fruits

CLASSIFICATION OF ANGIOSPERMS. 563

of the Rosaceae contain a number of FRUIT-ACIDS, such as malic,
citric, tartaric, and FRUIT-SUGARS, as dextrose and levulose. The
acids vary from 0.20 per cent, in pears to 1.50 per cent, in plums ;
and the sugars from 4.48 per cent, in peaches to 8.26 per cent,
in pears. The carbohydrates mannit and sorbit are found in the
fruit of Prunus Laurocerasus of Europe. In the unripe fruits
there is more or less tannin and also a principle known as PECTOSE.
This latter during the ripening of the fruit is converted into
PECTIN, a viscid principle which is further changed into pectic
and pectosic acids, the solutions of which gelatinize on cooling, so
that these fruits are adapted to jelly making (see pp. 243, 255).

Rubus nigrobaccus, or high bush-blackberry, is a branching
shrub i to 2 M. high with reddish, prickly, erect or recurved stems.
The leaves are 3- to 5~foliate, the leaflets being ovate, coarsely
and unequally serrate, and midrib and petiolules with stout, re-
curved prickles. The flowers are white, in terminal racemes and
with hairy and prickly stalks. The fruit is broadly ovoid and
consists of an aggregate, of drupelets which ripen in August and
September.

Rubus villosus Ait. (Rubus canadensis L.) or low-blackberry
(Northern dewberry) is a trailing, shrubby, prickly plant the
leaves of which are 3- to 7-foliate, the leaflets being oval or ovate-
lanceolate, serrate and nearly smooth. The flowers are in racemes
and the fruit resembles that of R. nigrobaccus, but is smaller.

Rubus cuneifolius or sand-blackberry of the Eastern and
Southern States is a small shrub less than i M. high, much
branched, and with straight or recurved, stout prickles. The
leaflets are ovate or cuneate, and densely pubescent, as are also
the young shoots. The inflorescence consists of two to five flowers,
the petals of which are white or pinkish. The fruit is oblong, more
or less cylindrical, and sometimes 20 mm. long.

Rubus Idccus or the cultivated European red-raspberry is a
shrub with a glaucous, bristly stem and with 3- to 7-foliate leaves.
The flowers are white and the red fruit consists of a cap-like col-
lection of hairy drupelets which is easily detached from the non-
fleshy receptacle. The fruit is used in the preparation of syrup
of raspberry which is used for flavoring. There are a number of
varieties of this species of raspberry in cultivation, the fruits of

564 A TEXi-iiOOiv oF BO i AIM.

which vary in color from crimson, brown, or yellow to nearly
white. The fine flavored but watery fruit of the wild red-rasp-
berry (R. strigosus) is sometimes substituted for the fruit of
Rubus Idccus ( Fig. 243 ) .

Rosa gallica, which yields the red rose-petals, official in a num-
ber of the pharmacopoeias, is a native of Southern Europe and
is extensively cultivated.

Rosa centifolia, which is now known only in cultivation, and
of which there are a large number of varieties, is distinguished
by its glandular leaflets, and its pale red or pink petals. The
cone-like collection of petals of the flower-bud is the part which is
used in medicine, but it is deficient in coloring .principles and
fragrance as compared to Rosa gallica.

Rosa damascena, the petals of which yield the oil of rose or
attar of rose, is extensively cultivated in Bulgaria and to some
extent in France and Germany. It flowers very profusely, and
the yield of oil is about 0.02 per cent. The oil consists of a crys-
tallizable hydrocarbon known as rose-camphor which is odorless,
and a liquid portion consisting of geraniol, 1-citronellol, 1-lina-
lool, citral, n-nonyllic aldehyde and phenyl ethyl alcohol. Similar
oils are obtained from other species of Rosa growing in Northern
Africa, Abyssinia and Northern India, as R. moschata, and
R. sempervirens.

The fruits of wild brier (Rosa canina) naturalized from
Europe, as well as of other species of Rosa (R. pomifera and
R. rugosa), contain considerable malic and citric acids and fruit-
sugars, and are made into a confection by boiling with syrup. In
addition to the fruit-ethers found in the common edible fruits
of this family and the volatile oil of rose, it should be mentioned
that oils containing salicylic acid are also present. A number of
species of Spiraea contain salicylic aldehyde and methyl salicylate.

Quillaja Saponaria is a large tree having a thick bark and
hard wood. The leaves are oval, coriaceous, slightly dentate and
evergreen (Fig. 316). The flowers are monoecious or dioecious,
white, apetalous, and axillary in groups of one to four. The
ovary consists of 4 to 5 carpels and on ripening forms a star-like,
spreading group of follicles. The inner bark is the part used in
medicine.

CLASSIFICATION OF ANGIOSPERMS.

565

A spurious quillaja bark (Q. Pocppigii) differs from the
official in being thinner, darker and in having the surface covered
with a coarse network of whitish lines. Another bark, occurring
in quilled pieces, from 8-15 cm. long, and 1-5 cm. wide, has also
been found in commerce.

Hagenia abyssinica is an ornamental tree with 7- to 13-foliate
leaves. The flowers are monoecious and occur in panicles ; the
staminate being greenish-yellow and with 20 stamens ; and the
pistillate fragrant, bicarpellary, and with a reddish calyx (Fig.

PlG. 316. Soap-bark tree (Quillaja Saponaria): A, flowering branch; B, one of the
hermaphrodite flowers; C, the latter in longitudinal section. — After Baillon.

317). The fruit is a nutlet. The pistillate flowers are official
under the name of Cusso.

Various species of Prunus yield GUMS, as cherry, peach,
apricot, etc. MUCILAGE is found in the testa of certain seeds, as
of quince. The manna of Luristan is obtained from Pyrus glabra
of Persia. Tannin and gallic acid are found in TORMENTILLA
rhizome which is obtained from Potentilla silvestris, a perennial
herb of Europe, and other species of Potentilla. The fruit of the
hawthorn (Crat&gus Oxyacantha) contains quercitrin. A bitter
principle and tannin are found in Purshia tridentata of the Rocky
Mountains. Phloridzin is found in the root bark of a number of
species of Pvnts and Prunus

566

A TEXT-BOOK OF BOTANY.

7

PIG. 317. Hagenia abyssinica: A, branch showing a large panicle of pistillate
flowers and the stipulate, compound leaves; B, C, staminate flowers; D, E, pistillate
flowers. — After Berg and Schmidt.

In the genus Fragaria to which the strawberry belongs, the
torus becomes large and fleshy and is the edible part of the fruit.
The garden strawberry (F. chilocnsis) has a large fruit, the
achenes being sunken in the periphery of the torus (Fig. 242). In

CLASSIFICATION OF ANGIOSPERMS. 567

the wild strawberries the fruit is smaller, usually somewhat flesh-
colored and the achenes are either embedded in the torus as in F.
virginiana or borne on the surface as in F. vesca. The strawberry
fruit contains about 87 per cent, of water; 6 per cent, of cane
sugar; 5 per cent, of invert sugar (a mixture of dextrose and
levulose) ; I per cent, of free fruit-acids; and about 2 per cent,
of nitrogenous substances.

g. LEGUMINOS^E OR PULSE FAMILY.— The plants are
herbs, shrubs, trees, or vines with alternate, stipulate and usually
compound leaves. The flowers are complete, and the corolla is
either regular or irregular; the stamens are usually united, and
the pistil is simple and free, becoming in fruit a legume. The
plants are widely distributed, many of them being found in the
Tropics. Three principal sub-groups, which have been ranked
as families by some botanists, are recognized.

1. PAPILIONAT.E. — Those species with papilionaceous flowers
are separated into a group called the Papilidnatae. This sub-group
has a number of representatives in the United States, as clover,
locust, and Baptisia (Fig. 280, L).

2. CESALPINIOIDE.E include the sennas and have flowers which
are nearly regular, or imperfectly, or not at all papilionaceous.

3. The MIMOSOIDE^E include the acacias and have flowers that
are regular.

Cassia acutifolia is a small shrub with leaves that are 8- to
i o- foliate. The leaflets are official as Alexandria or Tripoli senna ;
the flowers are yellowish and in axillary racemes; the fruit is a
smooth, flat, dehiscent pod, with 6 to 8 seeds.

Cassia angustifolia is a shrub which is cultivated in Southern
India and resembles Cassia acutifolia. The leaflets which consti-
tute India senna or Tinnevelly senna are longer and narrow-lanceo-
late, and the pods are longer, and slightly crescent-shaped, as
compared to those of C. acutifolia.

Cassia Fistula or purging cassia, the pods of which are used
in medicine, is a tree about 15 M. high. The leaves are 10 to 12-
foliate ; the flowers golden-yellow and in racemes ; and the fruit
is a very long, cylindrical, indehiscent legume. The leaves of
quite a number of species of Cassia are used in medicine and the

568

A TEXT-BOOK OF BOTANY.

following are the source of FOLIA MALABATHRI : C. Tamala of
Assam and C. javanica.

Glycyrrhiza glabra is a perennial herb, with 8- to 14- foliate

FIG. 318. Spanish licorice (Glycyrrhiza glabra) plant grown from a cutting
by the late Henry N. Rittenhouse of Philadelphia.

leaves (Fig. 318), the leaflets being glandular in the variety
glandulifcra; the flowers have a violet-colored, papilionaceous
corolla, and the fruit is a flat, dehiscent legume. The rhizome and
roots are the parts used in medicine.

CLASSIFICATION OF ANGIOSPERMS. 569

Cytisus scoparius or green or Scotch broom is a shrub nat-
uralized from Europe. The branches are numerous, slender, erect
and grow close together, adapting them for use as brooms. The
tops are used in medicine.

Tamarindus indica is a tree attaining a height of 25 M. The
leaves are pinnately compound, having numerous sessile, entire,

FIG. 319. Tragacanth plant (Astragalus gummifer)'. A, flowering branch; B,
modified, thorn-like leaf with stipules at the base; C, irregular (bilateral) flower; D, legume
of A. arislatus, — After Taubert.

oblong leaflets ; the flowers are in terminal racemes and the petals
are yellow with reddish veins ; the fruit is a curved, indehiscent
legume which has a thin epicarp and a pulpy sarcocarp with
numerous fibers, and contains a number of flat, quadrangular
seeds. The pulp is the part used in medicine as a laxative and
refrigerant.

Astragalus gummifer is a tomentose shrub less than I M.
high. The leaves are pinnately compound, the leaflets being narrow

570 A TEXT-BOOK OF BOTANY.

and elliptical ; the flowers are pale yellow, sessile and axillary ;
the fruit is a small, somewhat cylindrical, hairy pod or legume.
The gummy exudation constitutes the Tragacanth of commerce.

Acacia Senegal, which yields gum Arabic or acacia gum, is
a small tree with bipinnate leaves which are subtended by curved
spines ; the flowers are yellow and in dense spikes ; the fruit is a
broad pod containing five or six seeds.

Acacia Catechu is a small tree which resembles Acacia Senegal
and furnishes Black Catechu. '

Km

FIG. 320. Acacia Senegal: A, flowering branch: B, a single flower showing numerous
stamens; C, part of legume showing attachment of seeds; D, E, sections of seeds. —
Alter Taubert.

Pterocarpus Marsnpium is a fine timber tree with spreading
branches. The leaves are 5- to 7-foliate, the leaflets being cori-
aceous, obovate, and emarginate ; the flowers are pale yellow, and
the fruit is an indehiscent, orbicular pod with a single reniform
seed. The official Kino is prepared from the juice.

The trees yielding kino are under State control in Madras.
According to v. Hohnel the kino is present in special cells in the
bark, which are arranged in radial rows in the region of the lep-
tome. The cells are from 50 to ioo/x wide and from 100 to

CLASSIFICATION OF ANGIOSPERMS. 571

500 fj, long, the walls consisting of cellulose. The term " kino "
is applied to the red astringent juices obtained from a number of
plants. " AMERICAN KINO " is a synonym sometimes applied to
the extract of Geranium maculatum (Fam. Geraniacese).

Pterocarpus santalinus is a small tree with trifoliate leaves,
and flowers and fruits resembling those of P. Marsupiuin. The
heart-wood is official.

Hccmatoxylon campechianum is a small tree with irregular
spinous branches. The leaves are 8- to lo-foliate, the leaflets being
sessile and obcordate. The flowers are fragrant, have a purple
calyx and yellow corolla, and are in racemes. The fruit is a
slender, lanceolate, flat pod, which dehisces laterally instead of
along the sutures. The heart-wood of this tree constitutes the
commercial Logwood, of which about 200,000 pounds are con-
sumed annually, its chief use being as a dye-wood.

Krameria triandra is a shrub with a few, simple, ovate-lanceo^
late, sessile, silver-white, glistening leaves. The flowers are com-
plete, having two purple petals and three stamens. The fruit is a
i-seeded, globular, prickly, indehiscent pod. K. Ixina, found
growing from Mexico to Northern South America, and K. argen-
tea of Northern Brazil, are distinguished by having flowers with
three petals and four stamens. The root is the part used in
medicine.

Copaiba Langsdorffii is a small tree found growing in Brazil.
The leaves are 6- to 10- foliate, the leaflets being ovate-lanceolate,
glabrous, coriaceous, and glandular punctate. The flowers are
apetalous, and the fruit is an ellipsoidal, coriaceous, 2-valved pod
having a single glandular seed with an arillus. An oleo-resin
collects in longitudinal cavities in the trunk of the tree, often
amounting to many liters, and sometimes the pressure thus pro-
duced is sufficient to burst the trunk in places. The oleo-resin is
official as COPAIBA. The latter consists of 30 to 75 per cent, of a
volatile oil from which the sesquiterpene caryophyllene has been
isolated ; a bitter acrid resin and a bitter principle. A similar prod-
uct is obtained from a number of other species of Copaiba growing
in South America, as well as C. copallifera of Western Africa, and
Hardwickia Mannii of tropical Africa, and H. pinnata of India.

An oleo-resin known by the natives in the province of Velasco

572 A TEXT-BOOK OF BOTANY.

in Bolivia as " Copaiba " is obtained from Copaiba paupera. It
is thick, like Maracaibo balsam, but lighter in color and resembles
in odor and taste true copaiba. It is distinguished from the other
specimens of American copaiba by its dextro- rotation [a]D -f- 36°.
On the addition of one to two volumes of petroleum ether it forms
a clear solution, giving a white precipitate on the addition of
more ether.

Toluifera Balsamum is a tree about 25 M. high, with a straight
trunk, on which the branches first appear at a height of from
15 to 20 M., and is found growing in Northern South America.
The leaves are compound and with seven to eleven alternate,
oblong, acuminate, glandular-punctate leaflets; the flowers are
white and in simple axillary racemes ; the fruit is a winged, inde-
hiscent, I -seeded legume. The plants yield a balsam ( official in
all the pharmacopoeias and known as BALSAM OF TOLU) which
occurs in schizogenous cavities in the bark of young twigs, and
is obtained by incising the bark, it being usually collected in gourds.
The balsam consists of 75 to 80 per cent, of resin, which is a
compound of tolu-resinotannol, cinnamic and benzoic acids ; 18 to
20 per cent, of free cinnamic acid ; 0.2 to I per cent, of a volatile
oil; and 0.5 per cent, of vanillin. A good tolu balsam is also
obtained from T. peruifera growing in the northeastern part o>f
South America.

Toluifera Pereircc is a tree about 15 M. high, which has a
short trunk and begins to branch at a height of 2 or 3 M. It
otherwise resembles T. Balsamum. It is found over the whole of
Northern South America, extending through Central America to
Mexico, and is cultivated in Singapore. The balsam, which is
formed as a result of injury to the trunk, consists chiefly of esters
of benzoic and cinnamic acids, some free cinnamic acid, and vanil-
lin. A very fragrant vanilla-like balsam is obtained from the fruit
of this same plant, and in San Salvador it is known as white Peru
balsam to distinguish it from the black Peru balsam obtained
from the trunk.

Physostigma venenosum is a woody climber. The leaves are
3- foliate, the leaflets being ovate -acuminate; the flowers are violet
in color and in axillary racemes; the fruit is a broadly linear,
somewhat flattened, distinctly veined, dehiscent pod which tapers

CLASSIFICATION OF ANGIOSPERMS.

573

at both ends, and usually contains two or three seeds. The seeds
are official as Physostigma.

FIG. 321. Wild Indigo (Baptisia tinctoria), a perennial herb resembling a shrub,
possessing nearly sessile, 3-foliate leaves, and having, at the ends of the branches, loose
racemes of yellow flowers. A pale blue coloring principle has been obtained from the plant
resembling indigo, though somewhat inferior. — After Brown.

The blue coloring principle INDIGO is mostly obtained from
the herbs Indigo f era tinctoria and /. Anil which are indigenous

574 A TEXT-BOOK OF BOTANY.

to, and cultivated in, tropical and sub-tropical countries. It is
prepared by extracting the leaves with water. The glucosidal
principle indican (or mother-substance of indigo blue) undergoes
oxidation and the insoluble indigo blue separates out. This is the
commercial indigo. A similar principle is found in the wild indigo
(Baptism tinctoria) of the United States and Canada; the leaves
of Robinia Pseud-acacia of North America; several species of
Psoralea and Amorpha, as well as some other Leguminosse. It is
also found in other families, as in Polygonaceae, Cruciferse, Ascle-
piadacese, and Apocynaceae.

A yellow coloring principle is found in the dyer's broom
(Genista tinctoria) of Europe and Asia and naturalized in the
New England States. G. ovata of Europe yields a similar dye.

COPAL RESINS are derived from a number of the Leguminosse :
American copal from Hymen&a Coubaril of the West Indies and
South America ; Brazilian copal from H. Martiana of Rio Negro ;
Zanzibar or Chakazzi-copal from Trachylobium mossambicense of
Western Africa ; Sierra Leone copal (yellow gum, red gum) from
Copaiba Guibourtia of Sierra Leone; Inhambane copal from Co-
paiba conjugata and C. Gorskiana of Singapore, Jamaica and
Australia.

A number of the LOCO-WEEDS containing principles poisonous to
cattle belong to the Leguminosae. The word " loco," meaning
crazy, is of Spanish origin, and is applied in reference to the pecu-
liar nervous symptoms manifested by the affected animals. The
plants causing greater loss than all other poisonous plants com-
bined and regarded as loco-plants par excellence are Aragallus
Lamberti and Astragalus mollissimus. Of these two Aragallus
Lamberti, also commonly known as rattleweed or white loco, is the
most poisonous and has a wide range, extending from Alaska on
the north down through the whole grazing region of the Great
Plains, where it is very abundant. Astragalus mollissimus, known
as purple loco, woolly loco, or Texas loco, is more limited in its
range. Among other plants causing heavy losses to stockmen on
the grazing lands of the Great Plains east of the Rocky Mountains
may be mentioned the following : Zygadenus elegans ( Earn. Lili-
acese), especially dangerous to sheep ; the larkspurs or Delphiniums
(Earn. Ranunculaceae), causing losses among cattle; and lupines,

CLASSIFICATION OF ANGIOSPERMS. 575

causing losses especially among sheep. The water hemlock
(Cicuta maculata, Fam. Umbelli ferae) is poisonous to all higher
animals, including man. Among other plants poisonous to cattle
the following may be mentioned: California loco-weed (Astrag-
alus Crotalarice) , Texas or woolly loco-weed (A. mollissimus) ,
rattle-box (Crotalaria sagittalis) found in the Eastern United
States and Canada. The poisonous action of some of these plants
has been ascribed to the presence of barium salts, although this
has not been substantiated in all cases. Clitoria glycinoides of
Brazil and Phaca ochroleuca of Chile are poisonous to horses
and should probably be included with the loco-weeds.

A large number of the plants belonging to the Leguminosae
contain toxic principles' and those which have not already been
considered might be grouped according to the principles which
they contain.

1. ARROW-POISON group, including the genera Erythrophlceum,
Afzelia and Pithecolobium.

2. FISH-POISON group, including the genera Albizzia, Afzelia,
Bauhinia, Barbiera, Enterolobium, Leucaena, Millettia, Tephrosia,
Acacia, Abrus, Clitoria, Mundulea, Derris, Lonchocarpus, Pisci-
dia (P. Erythrina or Jamaica dogwood, which contains a curare-
like alkaloid).

3. SAPONiN-containing plants as the genera Acacia, Albizzia,
Entada (E. scandens or the sea bean of the East and West Indies),
Enterolobium, Gleditsia and Gymnocladus (G. dioica or Ken-
tucky coffee-tree growing in the United States and Canada).

4. CvTisiNE-containing plants ; the alkaloid cytisine is found in
Laburnum vulgar e and L. alpinum growing wild in Southern
Europe and also cultivated, and in one or more species of the
following genera : Anagyris, Baptisia, Coronilla, Crotalaria,
Genista, and Ulex.

Abrin, composed of a globulin and albumose and whose prop-
erties are affected at a temperature of 50° C. or over, is found in
the seeds of JEQUIRITY (Abrus precatorius) and Cassia hispidula
of Mexico; two alkaloids (lupinine and lupinidine) and a bitter
glucoside (lupinin) are found in the white lupine (Lupinus albus)
of Europe and in other species of Lupinus ; a glucoside (wistarin)
and a poisonous resin are found in WISTARIA, species of Wisteria,

576 A TEXT-BOOK OF BOTANY.

a common woody climber in cultivation as an ornamental plant;
the glucoside ononin is found in RADIX ONONIDIS, the root
of Ononis spinosa of Europe; the glandular hairs on the pods of
Mucuna pruriens and M. urens growing in the Tropics of both
hemispheres constitute the COWHAGE of medicine ; butyric acid is
found in ST. JOHN'S BREAD, the fruit of Ceratonia Siliqua, which
grows in European countries bordering the Mediterranean, and
also in Eperua falcata of Guiana.

A bitter principle, bondicine, known as poor man's quinine, is
found in Ccesalpinia Bonducella and other species of Cccsalpinia
growing in Sumatra, Borneo, New Zealand and Brazil ; the seeds
of Phaseolus lunatus of the East Indies contain a principle from
which hydrocyanic acid is derived.

The seeds of many of the plants belonging to the Leguminosse
are rich in starch and proteins and hence are used as foods. The
protein LEGUMIN is characteristic of this family. The following
are some of the important food plants: the garden pea (Pisum
sativum), the garden bean (Phaseolus vulgaris) ; lentil (Lens
esculenta), Japanese Soy bean (Glycine hispida). The peanut
(Arachis hypogcea) indigenous to Brazil and extensively culti-
vated in most of the Southern States and in Southern Europe,
belongs to the group of plants which have geocarpic fruits, that
is, fruits which penetrate the soil during their development and
ripen under ground (Fig. 231). In peanuts the starch is re-
placed by a fixed oil which is present to the extent of about 45
per cent, and which is an article of commerce. In addition to
the seeds mentioned those of a number of other plants as well
as some fruits, roots and leaves are used as foods in various parts
of the world, particularly in the Tropics. The plants of a number
of species are used as forage, as those of clover (Trifolium) ;
some are cultivated as ornamental plants, as sweet pea (Lathyrus
odoratus), and some yield valuable timber, as the locust (Robinia).

Soy Bean' (Glycine hispida) is an important food plant and
forage crop. The plant is an annual with trifoliate hairy leaves,
rather inconspicuous pale or violet-colored flowers, and with broad
pods containing 2 to 5 seeds. The seeds are more or less com-
pressed, spherical or elliptical and vary in color from whitish-
or yellowish-green to brownish-black. The yield of seed per

CLASSIFICATION OF ANGIOSPERMS. 577

acre may run as high as 40 bushels. As a forage crop it yields
as high as 2 to 3 tons of cured hay per acre. The seeds contain
about 5 per cent, of starch and nearly 50 per cent, protein sub-
stances. The seeds are therefore very nutritive and are exten-
sively used in feeding of live stock. In Japan the seeds are
known as " Soy," being derived from the Japanese word " Shoyu,"
in allusion to a preparation made from the seeds. In Europe it is
also used to a limited extent as a food. In this country it is used
to some extent as a food for persons suffering from diabetes.

ALFALFA or Lucerne (Medicago sativa) is one of the most val-
uable forage plants known to man. It is a perennial herb with
obovate-oblong leaves, bluish purple flowers occurring in
racemes, and twisted pods. Alfalfa is extensively cultivated in
all parts of the United States. It is an exceptionally deep-rooted
leguminous plant and under the best conditions is long lived,
growing in the arid lands of the West as well as in the rich soils
of the East. In many essentials and in feeding for stock alfalfa
resembles the clover. The alfalfa is relatively somewhat richer in
digestible protein than the clover but considerably lower in fat.

VEGETABLE BEZOARS are concretions formed in the stomachs
of ruminating animals. They consist of the hairs of crimson
clover and the awns of oats, barley and other cereal grains. They
are spherical in shape, of a yellowish-brown color, with smooth,
even surfaces, of a firm texture, and saturated with intestinal
juices. The balls when dried shrink but little and vary from 10 to
12 cm. in diameter. Since the introduction into the United States
of crimson clover as a forage plant or green manure, there have
been numerous deaths reported among horses and other cattle
due to their eating crimson clover, which leads to the formation
of bezoars caused by the undigested hairs matting together. An
examination of these bezoars shows that the hairs of which they
are composed, lie with the broken or basal end toward the center
of the ball, the sharp summit being directed toward the surface.

XVI. ORDER GERANIALES.

This order includes a number of families of economic impor-
tance. The sepals are mostly distinct ; the stamens are few ; the
carpels are united, and the ovules are pendulous (epitropous).
37

578 A TEXT-BOOK OF BOTANY.

a. GERANIACE^E OR GERANIUM FAMILY.— The
plants are herbs with alternate or opposite, usually stipulate leaves,
regular and perfect flowers, and capsular fruit ( Fig. 236, C) .

Geranium maculatum is a perennial herb (Fig. 322) with a
short, thick, horizontal rhizome, from which arises a simple, some-

FIG. 322. Geranium maculatum showing typical dicotyledonous flowers
and the s-parted, reticulately-veined leaves.

what branching, hairy stem, with 3- to 5-parted, variously toothed
and cleft, petiolate leaves, those on the upper part of the stem
being opposite; the flowers are regular and 5-merous, occurring
singly or in twos in the axils of the leaves; the petals are rose-
purple and hairy at the base ; the fruit is a dehiscent capsule ; the

CLASSIFICATION OF ANGIOSPERMS. 579

five carpels when ripe separate and roll upwards, remaining
attached to a central column by means of a slender carpophore, the
individual carpels being in the nature of achenes. The rhizome is
the portion used in medicine.

The cultivated geraniums belong to the genus Pelargonium,
and some of the species furnish oil of rose geranium, as P. odora-
tissimum, P. capitatum and P. Radula, all of which are cultivated
in France, Spain, Germany, Algiers and Reunion for the oil, which
is largely used in perfumery. The oil contains geraniol, cit-
ronellol, and various esters. The leaves of Pelargonium peltatum,
growing in certain parts of Africa and Australia, contain oxalic
acid and acid oxalates.

b. OXALIDACE^: OR WOOD-SORREL FAMILY.— To
this family belongs the genus Oxalis, some species of which have
leaves that are quite sensitive to light as well as mechanical
stimuli, which applies especially to the cultivated forms of South
Africa, and to the common wood-sorrel (Oxalis Acetosella) of
the United States and Canada, as well. The leaves contain oxalic
acid and acid oxalates.

c. THE TROP^OLACE^: OR NASTURTIUM FAMILY
comprises but a single genus, Tropaeolum. Some species are culti-
vated for ornamental purposes and are the nasturtiums of the
garden. The young shoots are succulent and taste like some of
the cresses, hence they have received the name " Indian cress."
They contain volatile constituents resembling those of the Cruci-
ferae, and in the leaves of Tropccolum majus benzyl mustard-oil
is found. The flower-buds and young fruits of this species are
used for pickling like capers.

d. LINAGES OR FLAX FAMILY.— The most important
plant of this family is the common flax (Linum usitatissimum) .
This is an erect, slightly branching annual herb with alternate,
lanceolate and 3-nerved leaves. The flowers are in terminal, leafy
panicles, the pedicels being slender, the calyx non-glandular, and
the petals blue (Fig. 280, A). The fruit is a lo-locular, lo-seeded
capsule. The seeds are official. There are a number of cultivated
varieties and the seeds of the var. hitmile contain a glucoside
which yields, under the influence of ferments, hydrocyanic acid.
A cathartic principle has been found in L. catharticum growing in

A TEXT-BOOK OF BOTANY.

Europe. The bast fibers of Linum usitatissimum are used in the
manufacture of linen. These fibers are distinguished from many
other vegetable fibers in not containing lignin.

e. ERYTHROXYLACE^: OR COCA FAMILY.— This
family contains but two genera, one of which is Erythroxylon.

FIG. 323. Flowering branch of Erythroxylon Ccca showing the parallel lines on either
side of the midrib, which are not true veins, brt due to an extra development of hypodermal
cells in this region. — After Reiche.

The official coca leaves (Fig. 323) are obtained from Erythroxy-
lon Coca. The plant is a shrub and requires a very humid atmos-
phere and a comparatively high elevation. The leaves are
alternate, petiolate and entire ; the flowers are white and very
small ; the fruit is a reddish drupe resembling that of dogwood.
Coca leaves contain several alkaloids, including cocaine, cinna-

CLASSIFICATION OF ANGIOSPERMS. 581

myl-cocaine, truxilline and ecgonine. Of these cocaine is the most
important, the Bolivian leaves containing the greatest amount, or
0.5 to i per cent. ; the other alkaloids preponderate in the Peruvian
leaves, which usually do not contain more than one-half or two-
thirds as much cocaine as the Bolivian leaves ; the Java leaves also
contain benzoyl-pseudotropine ; in addition, coca leaves contain a
volatile aromatic principle ; and a tannin giving a green color with
ferric salts.

COCAINE (benzoyl-methyl-ecgonine) occurs in monoclinic
prisms. The hydrochloride of cocaine with palladous chloride
forms a characteristic crystalline double salt (Fig. 97).

Other species of Erythroxylon also yield useful products. An
aromatic oil is found in the wood of E. monogynum of Ceylon
and India, and the wood is known as " bastard cedar " or " bastard
santal." A brownish-red coloring principle is found in the red-
wood (E. cerolatum) of Jamaica and in E. suberosum and E.
tortuosum. Purgative and anthelmintic principles are found in
some species of this genus.

/. ZYGOPHYLLACE;E OR CALTROP FAMILY.— The

plants are mostly herbs and shrubs which are widely distributed
in warm-tropical regions. The leaves are mostly opposite, pin-
nate and stipulate. The genus Guaiacum is of interest on account
of the wood containing considerable resin, which is used in
medicine.

Guaiacum officinale is a small tree with 4- to 6- foliate leaves,
the leaflets being ovate, entire and sessile; the flowers are large,
blue, and in axillary clusters ; and the fruit is a 2-valved capsule
(Fig. 324). G. sanctum is a tree resembling G. officinale, but is
distinguished by having leaves which are 8-foliate and with
smaller leaflets, and a 4- to 5-valved capsule. The resin of both
species is official.

A resin having an odor resembling that of creosote occurs in
the CREOSOTE BUSH (Covilleo, tridentata) of Mexico and Texas.

The juice of Peganum Harmala contains a yellow coloring
principle used in dyeing. A number of the plants of this family
contain powerful poisonous principles.

g. RUTACE^E OR RUE FAMILY.— The plants are shrubs
or trees, seldom herbs, with lysigenous oil-secretion cells. The

582

A TEXT-BOOK OF BOTANY.

leaves are usually alternate, simple or compound and glandular-
punctate (Fig. 280, C).

Zanthoxylum americanum or northern prickly ash is a shrub
or small tree with 5- to n -compound leaves, the leaflets being
ovate and nearly sessile; the flowers are dioecious, greenish, and
in axillary cymes ; the fruit is a black, 2-valved capsule. Z. Clava-
Herculis or the southern prickly ash is a very prickly shrub, which

FIG. 324. Guaiacum offlcinale: A, flowering and fruiting branch; B, gynaecium in
longitudinal section showing the pendulous ovules; C, a seed; D, E, the fruit in longitudinal
and transverse sections. — After Berg and Schmidt.

is characterized by having cork-wings on the bark. The leaves
are 5- to 17-foliate, the leaflets being ovate and crenulate; the
flowers are in terminal racemes and have a calyx of 4 or 5 sepals,
the calyx being wanting in Z. americanum. The bark of these
two species is official.

PILOCARPUS. — To this genus belong a number of species which
are shrubs or small trees and indigenous to tropical America.
The leaves are mostly pinnately-compound, the leaflets being
coriaceous and entire; the flowers are small, greenish and in
axillary or terminal racemes; the fruit is a i-seeded, 2-valved

CLASSIFICATION OF ANGIOSPERMS. 583

capsule. The leaves of three species are official as Pilocarpus
or Jaborandi.

BAROSMA. — The buchu leaves of medicine are obtained from
several species of Barosma (see Vol. II). The plants are branch-
ing shrubs with opposite, coriaceous, serrate or dentate leaves
with glandular margins ; the flowers are white or reddish and occur,
i to 3, in the axils of the leaves ; the fruit is a 5-valved capsule.
The leaves contain a volatile oil, one of the constituents of which
is diosphenol.

CITRUS.: — The fruits of a number of species of this genus are
edible, and the plants are also valued for their volatile oils. They
are aromatic, glandular, mostly thorny shrubs or small trees
indigenous to tropical and sub-tropical Asia, and now extensively
cultivated in tropical, sub-tropical and warm-temperate regions.
The leaves are more or less winged-petiolate, glaucous, coria-
ceous, mainly unifoliate (or trifoliate) ; the flowers are complete,
with a 3- to 6-toothed gamosepalous calyx, and 4 to 8 glandular
petals ; the stamens are 20 to 60, in groups of I to 9 ; the ovary
is subtended by a cushion-shaped disk, and the fruit is a spher-
ical, oblong or pear-shaped berry, having a coriaceous pericarp
with numerous lysigenous oil-glands, a juicy pulp made up of
peculiar hair-structures which arise from the endocarp, and in
which are embedded white polyembryonic seeds (Fig. 280, C).

Botanists have divided this genus into two sub-groups-: (a)
the Pseudo-y£gle group is represented by the trifoliate orange
(Citrus trifoliata), cultivated widely in the United States as a
hedge. The leaves are trifoliate and deciduous, the petals spatu-
late and the ovary and disk hairy, (b) In the Eucitrus group the
leaves are unifoliate and evergreen, the petals oblong, and the
ovary and disk glabrous. This latter group includes the two
species which yield most of the edible Citrus fruits.

Citrus Aurantium includes a number of sub-species and varie-
ties. The plants are small trees with leaves having winged
petioles; fragrant, white flowers; and a more or less globular
fruit. The SWEET ORANGE (Malta, Portugal) is derived from the
sub-species sinensis. The BITTER ORANGE (Seville, Curasao)
is derived from the sub-species amara. The flowers of both the
Sweet and Bitter Orange tree contain a volatile oil known as OIL

584 A TEXT-BOOK OF BOTANY.

OF NEROLI, and composed of limonene, geraniol, linalool, etc. The
oil from the rind of the fruit is known as OIL OF ORANGE PEEL, and
is obtained chiefly from Italy and Sicily. It is composed of
limonene, citral, citronellol, etc. The oil from the Bitter Orange
peel has a superior flavor and is known as BIGARADIA OIL. The
Bergamot Orange is the fruit of the sub-species Bergamia, culti-
vated in Europe, but only rarely in the United States. The oil of
the rind of the fruit is known as BERGAMOT OIL and consists
largely of linalyl acetate. In the group of MANDARIN or Kid-
glove orange (Citrus nobilis) the fruit is compressed, spherical,
5—6 cm. in diameter and with an orange-yellow, loose and easily
removable rind. The SHADDOCK or grape-fruit is derived from
the sub-species sinensis var. decumana, a tree indigenous to
the Malay Archipelago and extensively cultivated in India, Flor-
ida, California and elsewhere. The fruits are quite large, some-
times weighing several kilograms, and those which are round are
the most valuable commercially, being known as Pomelos or
GRAPE-FRUITS. The BLOOD ORANGE is the fruit of the sub-species
sinensis var. sanguined. The OTAHEITE ORANGE, which is ex-
tensively cultivated as a dwarf pot plant and the foliage and
flowers of which resemble those of lemon, is probably a variety of
the sub-species sinensis, or it may be a hybrid of lemon and orange.
The NAVEL ORANGE is a sweet orange in which an additional
compound ovary is developed within the fruit.

LEMON and LIME fruits are derived from sub-species of Citrus
Medico,, which are mostly shrubs with simple, petiolate leaves,
reddish twigs and flowers, and more or less ellipsoidal fruits.
Lemons are derived from the sub-species Limonum. The rind of
the fruit yields the OIL OF LEMON, which consists of limonene,
citral, etc. Most of the commercial article comes from Sicily and
Calabria. Lime fruits or limes are derived from the sub-species
acida, a shrub cultivated in the West Indies and Florida. The
CITRON fruit, the rind of which is used in the making of preserves
and confections, is derived from the sub-species genuina. The
fruit is large and lemon-like but with a thick rind, the plant being
cultivated to some extent in Florida and California.

The KUMQUAT ORANGE is obtained from Citrus japonica, a
thornless tree with spreading dwarf habit extensively cultivated

CLASSIFICATION OF ANGIOSPERMS. 585

in China and Japan and very hardy even in Northern Florida.
The fruit is round or oblong, from 3 to 5 cm. long and 2 to 3 cm.
in diameter, and of an orange-yellow color; the rind is sweet,
while the pulp is acid, and usually free from seeds, although from
i to 4 slightly beaked seeds may be present.

The inner white portion of the rind of the Citrus fruits con-
tains a crystalline, tasteless glucoside known as hesperidin (see
pp. 151-154). Those which are bitter contain in addition several
bitter glucosides, namely, aurantiamarin and naringin. (See
Aurantii Amari Cortex, and Aurantii Dulcis Cortex, in Vol. II.)

Volatile oils are also found in other members of the Rutaceae.
The garden rue (Ruta graveolens), the leaves of which are used
in medicine, contains a volatile oil consisting of several ketones.
It also contains a glucoside known as rutin which resembles the
barosmin of buchu ; and quercetin, which is said to be derived from
rutin. The Hop tree (Ptelea trifoliata) of Eastern North Amer-
ica contains besides a volatile oil, a resin and an alkaloid. The
volatile oil of pepper-moor (Zanthoxylum piperitum) of China
and Japan is known as Japanese oil of pepper.

ANGUSTURA BARK obtained from Cusparia trifoliata or C.
officinalis, plants growing in the region of the Orinoco River, con-
tains a volatile oil, resin, a bitter principle and four alkaloids.
The wood of Amyris balsamifera of Guiana and Jamaica, yields
on distillation a volatile oil resembling Oleum Rhodii.

h. SIMARUBACE;E OR AILANTHUS FAMILY.— The

plants are chiefly shrubs or trees with alternate and pinnately-
compound leaves. The flowers are regular, dioecious or polyg-
amous and in axillary racemes. The plants are natives of tropical
countries and are distinguished from the Rutaceae, which they
somewhat resemble by the absence of oil secretory cavities. They
are widely employed particularly in the tropics, on account of their
bitter principles, and are considered valuable tonics, febrifuges
and remedies for dysentery.

Picrasma excelsa is a small tree with 9- to I7~foliate leaves,
the leaflets being ovate and more or less tomentose, particularly
in the bud ; the flowers are yellow, polygamous and in axillary
panicles ; the fruit is a large, spherical drupe. The wood of the
plant constitutes Jamaica quassia.

586 A TEXT-BOOK OF BOTANY.

Quassia amara is a small tree or shrub with 4- to 5-foliate
leaves; the leaflets are narrow, obovate and acuminate, and the
rachis and petiole or stalk are winged ; the flowers are her-
maphrodite, with 10 stamens, bright red corolla, and in terminal
racemes; the fruit is a 5-valved indehiscent pod or nutlet. The
wood constitutes Surinam quassia.

A red coloring principle is found in Samadera indica of India,
Ceylon and Java. The alkaloid cedronin is found in the seeds of
Simaba Cedron of New Granada, the seeds being used as an anti-
dote for the bites of poisonous animals. A similar principle may
exist in the bark of Simaruba versicolor of Brazil, the plant being
used for a similar purpose. The alkaloid brucamarine is found
in the fruit of Brucea sumatrana. A tragacanth-like gum is
obtained from Ailanthus excelsa of India. DIKA or GABUN CHOC-
OLATE is obtained from the seeds of Irvingla gabonensis of trop-
ical West Africa. Cay-Cay-Butter is obtained from the seeds of
Irvingia Oliveri and /. malayana of Malacca and Cochin China.

A gum resembling acacia is also obtained from the bark, peti-
oles and seeds of the species of Irvingia.

i. BURSERACE^: OR MYRRH FAMILY.— The plants are
shrubs or trees, the latter being sometimes quite large, with
resin-canals in the bark, and alternate compound leaves ; the
flowers are small, occurring in racemes. The members of this
family are found in tropical countries.

Commiphora abyssinica is a shrub 10 M. high, the branches
being modified to thorns ; the leaves are trifoliate, the leaflets being
oblong, dentate, sessile and the terminal one much larger than
the other two ; the flowers are dioecious, and the fruit is a drupe
with a fleshy, resinous sarcocarp. The official Myrrh is probably
obtained from this plant as well as other species of Commiphora.

A number of other resinous products are yielded by plants of
this family. West India ELEMI resin or Elemi Occidentale
(Anime) is obtained from the stems of Protium Icicariba of
Brazil. The resin is greenish-yellow, soft, with a bitter taste and
dill-like odor. Manila Elemi is a soft, granular, lemon-yellow or
grayish-white resin derived from Canarium commune of the
Philippine Islands. Bengal Elemi is derived from Commiphora
Agallocha of the East Indies and Madagascar. The TACAMAHAC

CLASSIFICATION OF ANGIOSPERMS. 587

RESINS are balsamic resins, of which there are several commercial
varieties : Mauritius tacamahaca is obtained from Protium hepta-
phyllum of Columbia, and Mexican or West Indian tacamahaca
from Bursera tomentosa of Mexico, West Indies, and South
America. INDIA BDELLIUM is a resin obtained from the bark of
Commiphora Roxburghiana of Northwestern India and Belu-

•* T I J

FIG. 325. Myrrh plant (Commiphora abyssinica): A, young branch showing tri-
foliate leaves; B, flowering and fruiting stem with thorn-like branches; C, leaf axis in which
occur a fruit and staminate and pistillate flowers; D, staminate flower in longitudinal
section; E, longitudinal section of pistillate flower; F, longitudinal section of fruit showing
arillus-like mesocarp and the easily dehiscent endocarp. — After Engler.

chistan. CopAL-like resins are obtained from Canarium ben-
galense (East Indian Copal) and possibly several species of Bur-
sera. BLACK DAMMAR resin is obtained from Canarium ros-
tratum of the Molucca Islands. OLIBANUM or Frankincense is a
gum-resin obtained from several species of Boswellia of Asia and
Somaliland. AMERICAN OLIBANUM or Soft Resin of Cayenne
exudes spontaneously from the stems of Protium heptaphyllum
and P. guianense. GILEAD BALSAM is obtained from Protium

588 A TEXT-BOOK OF BOTANY.

altissimum and P. Carana of Guiana and Brazil. MEXICAN LIN-
ALCE OIL is obtained from Bursera graveolens, and several species
of Bursera of Mexico are used as a substitute for Aloe wood.

/. MELIACE^E OR MAHOGANY FAMILY.— This is a
large family of tropical trees and shrubs with mostly alternate,
compound and exstipulate leaves, the leaflets being entire, with
secretion cells, but not glandular-punctate (Fig. 326). The flowers

FIG. 326. Pride of China (Melia Azedarach): A, flowering branch; B, a part
of the inflorescence. — After Harms.

are complete, the filaments being united into a tube ; and they
occur in axillary clusters or racemes ; the fruit is a capsule, berry
or drupe ; the seeds are sometimes winged and with fleshy or leaf-
like cotyledons.

The bitter principle mangrovin is found in the bark of the
China Tree or Pride of China (Melia Azedarach) indigenous to
Asia, and extensively cultivated in tropical and warm-temperate
regions, and naturalized in the southern part of the United States
(Fig. 326). A similar principle is found in other plants of this
family.

CLASSIFICATION OF ANGIOSPERMS. 589

Carapa Oil, which has a characteristic odor and bitter taste
and is toxic to insects, is obtained from the seeds of Carapa pro-
cera and C. guianensis, of tropical West Africa and tropical
America, and also from Swietenia Mahagoni (Mahogany Tree).
Cedar- wood oil ("Oleum Cedreke ") is obtained from several
species of Cedrela growing in tropical America. The most impor-
tant constituent of the oils is cadinine. Oils with a garlic-like
odor are found in the seeds of Melia Azedarach, the bark of
Cedrela australis of Australia and the fruit of Dysoxylum binec-
tariferum of Java. Besides the Mahogany tree there are other
trees of this family which yield valuable woods. Cigar boxes and
sugar boxes are made from the wood of Cedrela odorata of the
West Indies and Guiana, and from other species of Cedrela.

k. MALPIGHIACE^E is a rather large family of shrubs,
small trees, or lianes with anomalous stem-structure, • found in
the Tropics, principally in South America. The leaves are usually
opposite, the sepals are glandular, and the fruit is a winged samara
somewhat like that of maple (Acer).

The plants contain a notable amount of tannin and the woods
of some species contain a red coloring principle.

/. POLYGALACE^: OR MILKWORT FAMILY.— The
members of this family are herbs or shrubs, occurring in all parts
of the world except in the Arctic regions.

Polygala Senega is a perennial herb about ^3 M. high. It has
a fleshy root, producing at the crown a large number of buds and
giving rise to a cluster of overground stems or so-called plants.
The leaves are alternate, lanceolate or oblong-lanceolate and ses-
sile ; the flowers are faintly greenish- white and in cylindrical
spikes ; the capsule is loculicidally dehiscent, and the seed is hairy
and slightly longer than the lobes of the caruncle. The root is
official.

Polygala alba or White Milkwort yields the White or Texas
Senega. The stems are numerous and taller than those of P. Sen-
ega; the leaves are narrow-lanceolate or linear with revolute mar-
gin ; the flowers are white and in elongated conic spikes ; the
caruncle lobes are about half as long as the seed. The plant is
found west of the Mississippi River, extending as far south as
Texas and Mexico and west as far as Arizona and New Mexico.

590

A TEXT-BOOK OF BOTANY.

m. EUPHORBIACE^: OR SPURGE FAMILY.— The
plants are herbs, shrubs or trees with acrid and often milky
latex. The fruit is mostly a trilocular, dehiscent capsule ; the seeds
are anatropous and have an oily endosperm.

FIG. 327. Stillingia sylvatica: showing the more or less closely arranged leaves
and the terminal spike of flowers. — After Bentley and Trimen.

Stillingia sylvatica or Queen's-Root yields the official Stillingia
(Fig. 327). The plant is a perennial herb about I M. high and
diffusely branched. The leaves are obovate, short-petiolate, with
glandular-serrate margin ; the flowers are in terminal spikes, light
yellow, monoecious, the staminate being above and the pistillate
below, the latter solitary in the axils of the lower bractlets.

CLASSIFICATION OF ANGIOSPERMS. 591

Ricinus communis or Castor-Oil Plant is an annual herb in the
temperate regions but is shrub-like and perennial in tropical and
sub-tropical countries. In temperate regions the plant is from
i to 5 M. high ; the leaves are peltate and 6- to i i-palmately-lobed ;
the flowers are greenish, apetalous, monoecious and in racemes,
the pistillate being above the staminate on the flower-axis; the
fruit is a 3-locular, oval, spinous capsule, which dehisces septi-
cidally (Fig. 237, B). The seeds are anatropous, somewhat flat-
tened-oblong ; 10 to 16 mm. long and 4 to 8 mm. in diameter;
smooth, mottled grayish-brown or yellowish-red, with a promi-
nent caruncle ; hard but brittle testa, thin white tegmen, large oily
endosperm, and thin foliaceous cotyledons at the center. The
seeds contain 45 to 50 per cent, of oil which constitutes the Castor
Oil of medicine and a large amount of proteins in the form of
aleurone grains (Fig. 250, D). The cake from which the oil is
expressed contains a poisonous principle known as ricin which
is apparently poisonous to cattle, but not to poultry.

Croton Tiglium is a shrub or small tree indigenous to tropical
Asia and extensively cultivated in tropical countries; the leaves
are alternate, oblong-lanceolate with petioles which are glandular
at the base, but wanting in the star-shaped hairs so characteristic
of other species of this genus ; the flowers are small, monoecious
and in terminal racemes, the pistillate being above and the stam-
inate below ; the fruit is a 3-locular, septicidally dehiscent capsule.
The seeds resemble those of Ricinus in size and structure, except
that they are less smooth, more brownish in color and the caruncle
is quite small.

They contain a fixed oil which is obtained by expression and
which is poisonous and a powerful cathartic. The seeds of a
number of the other members of the Euphorbiaceae contain fixed
oils resembling those of Croton and Ricinus, as CURCAS, the seeds
of Jatropha Curcas of tropical America. MEXICAN CROTON OIL
is obtained from th« seeds of Euphorbia calyculata. The seeds of
the Caper Spurge or Wild Caper (Euphorbia Lathyris), nat-
uralized in the United States from Europe, also contain a fixed
oil resembling that of Croton. The seeds of Joannesia Princeps
of the maritime provinces of Brazil are also powerful purgatives.

Mallotus philippinensis is a shrub or small tree found in trop-

592 A TEXT-BOOK OF BOTANY.

ical countries of the Eastern Hemisphere: The leaves are alter-
nate, petiolate, ovate, acuminate, coriaceous and evergreen; the
flowers are small, dioecious, and in racemes ; the fruit is a 3-locular,
glandular-hairy capsule. The hairs of the capsule are official in a
number of pharmacopoeias under the name of KAMALA and occur
as a reddish-brown, granular powder, consisting of two kinds of
hairs, the one colorless and occurring in branching clusters (Fig.
151) and the other with yellowish-red, multicellular, glandular
heads. The important constituent is about 80 per cent, of a dark
brownish-red resin composed of a crystalline principle rottlerin,
isorottlerin, two reddish-yellow resins, a coloring principle and
wax. It also contains a trace of volatile oil, starch, sugar, tannin,
oxalic and citric acids.

A red coloring principle is found in the bark of Aleurites
triloba of the Polynesian Islands, Euphorbia parviflora of Ceylon,
E. pulcherrima of Mexico and Brazil and the other species of
Euphorbia.

CASCARILLA BARK is obtained from Croton Eluteria and other
species of Croton growing in the Bahama Islands and other parts
of the West Indies and Florida. Cascarilla bark is official in a
number of pharmacopoeias. It occurs in small curved pieces or
quills, i to 3 mm. thick, externally brownish-gray ; inner surface is
reddish-brown, the fracture short, resinous ; odor aromatic ; partic-
ularly on burning; taste aromatic and bitter. Cascarilla contains
I to 1.5 per cent, of a volatile oil, containing eugenol, limonene, an
oxygenated portion, and some other constituents; 15 per cent, of
resin ; a bitter principle, cascarillin ; tannin and vanillin.

COPALCHI BARK or Quina blanca which is derived from Croton
niveus of Mexico contains a bitter principle, copalchin, which is
also found in other species of Croton. Malambo bark is derived
from Croton Malambo of Venezuela, the latter two barks being
sometimes substituted for Cascarilla bark.

ELASTICA or India Rubber (Caoutchouc) is the prepared milk-
juice obtained from one or more species of the following genera :
Hevea, Mabea, Euphorbia, etc. (see pp. 238-241). The fresh
latex of a number of species is a powerful irritant, as that of the
Sand-box tree (Hura crepitans] of tropical America, which con-
tains a highly toxic albuminoid; the Blinding-tree (Excrecaria

CLASSIFICATION OF ANGIOSPERMS. 593

Agallocha) of Southern Asia and Australia, the juice of which
produces blindness.

The gum-resin EUPHORBIUM is obtained from Euphorbia res-
inifera, a cactus-like plant of Morocco, and is also found in other
species of Euphorbia. It contains, among other constituents, 38
per cent, of an acrid resin, and 22 per cent, of a crystalline prin-
ciple euphorbon.

The milk-juice of several species of Euphorbia is used in the
preparation of arrow poisons in Brazil. One or more species of
the following genera are used as fish poisons : Flueggea, Phyl-
lanthus, Bridelia, Exccecaria and Euphorbia. A number of plants
are used as remedies for the bites of serpents, as the bark of
Phyllanthus mollis of Java and Euphorbia pilulifera of South
America and India. Euphorbia pilulifera, common in tropical
countries, contains an alkaloid, a wax-like substance, several
resins and tannin. (Ph. Jour., 29, July 31, 1909, p. 141.)

A camphor-containing oil is found in the bark of Pentalo-
stigma quadriloculare of Australia; the aromatic wood of Col-
liguaya odorifera of Chile is used as a substitute for santal and
on burning emits a rose-like odor; the leaf of Croton mentho-
dorus of Peru contains an oil with an odor of mentha ; a balsam
resembling Copaiba is derived from the bark of Croton origani-
folius of the West Indies ; methylamine is found in Mercurialis
annua of Europe and other species of Mercurialis. Tannin is
found in the following genera: Macaranga, Phyllanthus and
Bridelia; Brazil kino is obtained from a species of Croton (C.
erythrceus?) of Brazil. A gum-lac is formed on the stems of
Aleurites laccifera of the Antilles and Ceylon as a result of the
sting of an insect, and contains among other substances a large
amount of methyl- and ceryl-alcohols, and a substance resembling
abietic acid. The sap of Euphorbia Cyparissias of Europe yields
a resin which is sometimes substituted for scammony.

A reddish resinous substance resembling dragon's blood is
obtained from Croton erythrema of Brazil; a yellow coloring
principle is found in the seed of Croton tinctorius of Mexico;
poncetin, a violet coloring principle, occurs in Euphorbia hetero-
phylla of Brazil; a blue coloring principle is found in Chrozo-

phora tinctoria of Southern Europe and Africa and in Argitham-
38

594 A TEXT-BOOK OF BOTANY.

nia tricuspidata lanceolata of Chile; an indigo-like principle is
obtained from Mercurialis perennis of Europe. The fresh latex
of Euphorbia phosphorea of Brazil is phosphorescent.

Quite a number of the seeds of this family contain fatty oils.
The Chinese Tallow tree (Sapium sebiferum) yields a fat which
is used for burning and for technical purposes ; a similar fat is
obtained from the seeds of several species of Aleurites and
Euphorbia.

TAPIOCA starch is derived from the tuberous roots of Manihot
utilissima, extensively cultivated in tropical countries; other spe-
cies of Manihot also yield starchy food products.

Edible fruits are obtained from the following genera : Phyl-
lanthus, Baccaurea and Antidesma ; the seeds of Hevea brasiliensis
are edible ; a sweet sap is found in Baccaurea ramiftora of Cochin
China and Brazil ; a peptone-like ferment is found in Euphorbia
heterodoxa of South America and other species of Euphorbia.

XVII. ORDER SAPINDALES.

The plants of this order are chiefly trees and shrubs. The
flowers are mostly regular and the seeds usually without endo-
sperm. The order has a number of representatives in both tropical
and temperate regions.

a. BUXACE^ OR BOX TREE FAMILY.— The plants are
shrubs with alternate or opposite, evergreen leaves, and usually
axillary monoecious or dicecious flowers. The most important
plant of this family is the Box tree (Buxus sempervirens) , which
is extensively cultivated. The wood is used for making musical
instruments and for other purposes, and the twigs have been used
in medicine. The latter contain several alkaloids, the most impor-
tant being buxine, which resembles beberine ; a volatile oil con-
taining butyric acid and a wax containing myricyl alcohol and
myricin.

b. FAMILY CORIARACE^E.— This family is represented
by but a single genus, Coriaria. The plants are shrubs found
in Europe, Asia and South America, and yield several important
economic products. The leaves and bark of C. myrtifolia of
Southern Europe and Northern Africa are rich in tannin and used
in dyeing. This plant also contains a narcotic principle, resem-

CLASSIFICATION OF ANGIOSPERMS. 595

blmg picrotoxin, known as coriamyrtin, which is also found prob-
ably in C. atropurpurea of Mexico. The leaves of Coriaria myrti-
folia or TANNER'S SUMAC are coriaceous, distinctly 3-nerved,
astringent and bitter and were at one time substituted for senna
leaves. A black dye is obtained from C. ruscifolia of New Zealand
and Chile. While the fruits of some species are quite poisonous,
the sap of the fleshy leaves is used in New Zealand in making
an intoxicating drink.

c. ANACARDIACE^E OR SUMAC FAMILY.— The plants
are trees or shrubs with an acrid, resinous or milky latex, and
alternate leaves.

Rhus Toxicodendron, POISON IVY or Poison Oak, is a woody
vine, climbing by means of aerial roots and sometimes becoming
quite shrub-like, which is common along roadsides in the United
States. The leaves are 3-foliate, the leaflets being ovate, acumi-
nate, nearly entire, inequilateral and with short stalks ; the flowers
are green and in loose axillary panicles ; the fruit is a globular,
glabrous, grayish drupe (Fig. 328). The nature of the poisonous
constituents of Poison Ivy is not definitely known. It was orig-
inally considered to be in the nature of a volatile principle. Pfaff
and his pupils seemed to show that the poisonous principle was a
non-volatile brownish-red resin which is soluble in alcohol and
called toxicodendrol. Schwalbe, on the other hand, states that
the poisonous substance is of a volatile nature, being formed in the
laticiferous vessels and by osmosis is transferred to the hairs.
The poison may be transmitted either by direct contact with the
hairs, much as in the same manner with the nettles, or by volatiliza-
tion of the oil when the hairs are broken. The experience of most
plant collectors would seem to indicate that in Poison Ivy there
is a volatile toxic constituent (Amer. Jour. Pharm., March, 1914).
On the other hand, Rost and Gilg were unable to find a volatile
poison in either the hairs or pollen of Poison Ivy. In some ex-
periments conducted by Warren on pollen grains, similar negative
results were obtained {Amer. Jour. Pharm., Dec., 1913). The
poisonous principle occurring in several species of Rhus is an
amber-red, non-volatile liquid. It is of a resinous nature, com-
bining with the alkali hydroxides to form nigrescent compounds,
and otherwise behaves like certain phenolic compounds. The toxic

59^

A TEXT-BOOK OF BOTANY.

resin exists in the plant in the form of an emulsion which readily
blackens with the alkali hydroxides. So delicate is this reaction
that minute amounts of the substance may be detected by means

FIG. 328. Leaves and fruit of the poison ivy (Rhus radicans). This is a 3-foliate com-
pound leaf, the leaflets being ovate and having veins which bifurcate and end free.

of the microscope if the plant tissues are mounted in an alcoholic
solution of potassium hydroxide. A vesicating principle CARDOL
is found in the CASHEW NUT. The latter is the fruit of Anacardium

CLASSIFICATION OF ANGIOSPERMS. 597

occidentale, a shrub growing in tropical America. A principle
resembling cardol is found in the East India Marking tree or Ink
tree (Seniecar pus Anacardium)a.nd Holigarna ferruginea of India.

The POISON SUMAC or Poison Elder (Rhus Vernix) is a shrub
or small tree found in swamps in the United States and Canada.
The leaves are 7- to 13-foliate, with obovate or oval, acuminate,
entire leaflets ; the flowers are small, green, and in axillary pani-
cles; the fruit resembles that of R. radicans (Fig. 328). The
plant is poisonous like R. Toxicodendron and probably contains the
same principle. Other species of Rhus are also poisonous, as the
western Poison Oak (R. diversiloba) of the Pacific Coast, and
the Japanese Lacquer or Varnish tree (R. vernicifera and R.
succedanea). The lacquer trees grow wild in both China and
Japan, where they are also cultivated. The lac is obtained by
incising the bark and removing it with a pointed spatula. The
grayish-white emulsion is strained and on exposure to air it
changes to brown, becoming finally black. This change is due to
the oxidizing enzyme laccase. The natural lac (Kiurushi) contains
a non-volatile poisonous resin-like principle and is closely associ-
ated with other resinous substances. Japanese lac is thinned with
camphor, or mixed with linseed oil, and on drying in a moist atmos-
phere forms the most indestructible varnish known. Various pig-
ments are used, as vermilion, gamboge, acetate of iron and other
substances. The best glossy black colors are obtained by the
addition of iron.

Rhus glabra or the Scarlet Sumac is a smooth shrub. The leaves
are n- to 31 -foliate, the leaflets being lanceolate, acuminate, sharply
serrate, dark green above and lower face glaucous ; the flowers are
greenish, polygamous and in terminal panicles ; the fruits of this
plant and of R. typhina (Fig. 329) are used in medicine.

CHINESE GALLS are excrescences produced on Rhus semialata
as a result of the stings of an Aphis. JAPANESE GALLS are similar
formations occurring on Rhus japonica. (See pp. 206, 334.)

Pistacia Lentiscus is a shrub or tree, which is found growing
in the Grecian Archipelago. The leaves are pinnately compound
and with winged axis, the leaflets being alternate, oblong, entire,
sessile; the flowers are small, dioecious, and in axillary clusters.
In the bark of this plant there are large cavities which contain

598

A TEXT-BOOK OF BOTANY.

\

FIG. 329. Fruiting branch with leaves of Rhus typhina. Reproduced from Sargent's
"Silva of North America."

Rhus typhina is commonly known as the " staghorn sumac" in allusion to the soft
brown pubescence covering the twigs and branches. It is also known as the " vinegar tree "
and " Virginia sumac." It may attain the height of a tree, and is usually found growing in
uplands in good soil, ocasionally being found like Rhus glabra on barren gravelly banks. It
is very abundant in the eastern United States and apparently sparingly distributed west of
the Appalachian Mountains.

CLASSIFICATION OF ANGIOSPERMS. 599

an oleo-resin that is official as Mastic in a number of pharmaco-
poeias (see Vol. II). The wood of Schinopsis Lorentzii and S.
Balansa, growing in Argentine and Paraguay, is known in com-
merce as QUEBRACHO COLORADO. It is red, very hard and contains
tannin, gallic and ellagic acids.

The PISTACIO nuts or Pistacia almonds are obtained from
Pistacia vera indigenous to Syria and Mesopotamia and exten-
sively cultivated in the countries bordering the Mediterranean.
The kernels are used extensively in confectionery. The nuts are

FIG. 330. Gallic acid: long orthorhombic crystals obtained from an aqueous solution.

about 20 mm. long, somewhat quadrangular in cross section, and
the seed consists of two fleshy, green cotyledons. The seeds of
Buchanania latifolia and other species of Buchanania are used in
India much like almonds.

Gums are found in several species of Anacardium and Sclero-
carya. ACAJOU GUM is obtained from Anacardium occidentale.
Considerable sugar and citric acid are found in MANGOS, the
fruit of Mangifera indica native of Farther India and Ceylon and
cultivated in the Tropics. A fruit used like lemons is obtained
from Dracontomelon mangiferum of Malacca and the Sunda
Islands.

6oo A TEXT-BOOK OF BOTANY.

d. AQUIFOLIACE^: (ILICACE^E) OR HOLLY FAM-
ILY.— The plants are mostly shrubs or trees with alternate, petio-
late, simple leaves and small, white, regular flowers. The fruit
is a berry-like drupe containing several nutlets. The most im-
portant genus of this family is Ilex, a number of species of which
are found in the United States.

The European holly (Ilex Aquifolium) contains a bitter gluco-
sidal principle, ilicin, which is found in the bark as well as the
drupes. The drupes contain a principle which is a homologue
of benzyl alcohol, and a glutinous substance which renders them
useful in the manufacture of bird lime. The American holly (/.
opaca) growing in the Eastern United States probably contains
similar constituents to the European holly. This is the plant
which furnishes the CHRISTMAS HOLLY.

MATE, Paraguay or Brazilian tea, consists of the leaves of
Ilex paraguariensis (Fig. 331) found in Brazil, Argentine and
Paraguay. They contain about 2 per cent, of caffeine, 1 1 per
cent, of tannin and some volatile oil, and are used like tea in the
making of a beverage. Cassine or Appalachian tea consists of
the leaves of the Dahoon holly (Ilex Cassine) growing in the
Southern United States. These leaves contain about half as much
caffeine and tannin as Mate.

e. CELASTRACE^: OR STAFF-TREE FAMILY.— These
are shrubs, as Euonynms, or woody climbers, as the climbing bit-
tersweet (Celastrus scandens). The plants are especially charac-
terized by their dehiscent fruits and scarlet or reddish arilled seeds.

Euonymus atropurpureus (Wahoo or Burning Bush) is a
shrub or small tree. The twigs have four distinct cork-wings,
making them somewhat 4-angled. The leaves are opposite, petio-
late, ovate-oblong, acuminate, crenulate-serrulate and hairy be-
neath. The flowers are purplish and in axillary cymes. The f ruitJ
is a 3- to 4-lobed, persistent, loculicidally dehiscent capsule with
6 to 8 scarlet seeds. The bark of the root is official.

The leaves of Catha edulis growing in Arabia and Abyssinia
are chewed and also used like tea. They contain the alkaloids
cathine and celastrine which are supposed to have similar proper-
ties to cocaine, as well as tannin and an ethereal oil. A yellow
coloring principle is found in the bark of Euonymus tingens of

CLASSIFICATION OF ANGIOSPERMS.

60 1

> 6 I* • '

mm

FIG. 331. Yerba Mate trees (Ilex paraguariensis) growing in Pereira Continhoand
Almeido, Santos, Brazil. The plants are shrubs or small trees, with ovate or nearly spatu-
late, dentate and slightly coriaceous leaves. The latter are used, under the name of Para-
guay tea, in the preparation of a tea-like beverage. The trees are extensively cultivated
in South America, and large quantities of Mate" are consumed annually. The young branches
are gathered between December and August, dried over a fire, the leaves being separated,
and are then ready for market. — Reproduced by permission of The Philadelphia Com-
, mercial Museum.

602 A TEXT-BOOK OF BOTANY.

the East Indies. The yellow coloring principle in the arils of the
seeds of Celastrus and Euonymus appears to closely resemble
carotin. The seeds of a number of plants of this family contain
a considerable quantity of fixed oil, as Celastrus macro car pus of
Peru, and Maytenus Boaria of Chile.

/. ACERACE^: OR MAPLE FAMILY.— The plants of this
family are trees or shrubs, the most widely distributed repre-
sentative of which is the maple (Acer). The most distinguishing
character of this family is the fruit, which is a double samara.
The sap of a number of species of Acer contains cane sugar or
sucrose, and the sap of the sugar maple (Acer saccharinum) which
grows in the United States and Canada contains from 3 to 4 per
cent. The making of maple syrup and maple sugar is quite an
industry in some localities. Maple sugar is also obtained from
the black sugar maple (Acer nigrum) and the ash-leaved maple
(A. Negundo). The bark of the latter species is used to some
extent in medicine. Valuable timber is yielded by the maple trees.

g. HIPPOCASTANACEyE OR BUCKEYE FAMILY.—
The plants are shrubs or trees with opposite, petiolate, and 3- to
9-digitately-foliate leaves. The flowers are in terminal panicles
and the fruit is a 3-lobed capsule, which usually contains one
large, shiny seed.

The horse-chestnut (sEsculus Hippocastanum) contains in the
bark two fluorescent bitter principles, sesculin and paviin, the
former of which is in the nature of a glucoside ; and in the bark,
leaves and flowers the coloring principle, quercitrin is present;
in the seed-coat saponin is supposed to occur, and the glucoside
sesculin as well. The cotyledons contain considerable starch, some
proteins and sugar, a small quantity of a fixed oil, and argyresin,
to which the antihemorrhoidal action appears to be due. A
narcotic principle is present in the bark, twigs and leaves of the
red buckeye (JEsculus Pavia) of the Southern United States.

h. SAPINDACE^ OR SOAPBERRY FAMILY.— The
plants are mostly trees or shrubs indigenous to the Tropics. In
some genera they are herbaceous or woody vines (lianes). The
plants of this family usually have either a milky sap or contain
saponin, and it seems strange that a plant yielding caffeine, namely,

CLASSIFICATION OF ANGIOSPERMS. 603

Paullinia Cupana, which furnishes the official Guarana, should
belong to this group.

The fruit shells of Nephelium lappaceum contain a toxic sapo-
nin (Ph. Weekblad., 45, i, 156, 1908). Four or five per cent.

FIG. 332. Flowering and fruiting branch of Brazilian cocoa (Paullinia Cupana) yielding
the Guarana used in medicine. — After Radlkofer.

of SAPONIN is found in the fruit of Sapindus trifoliatus of India.
A principle related to saponin is found in Sapindus Saponaria of
tropical America. Saponin is also found in the fruits of other
species of Sapindus, the bark of Pometia pinnata of the Sunda

604 A TEXT-BOOK OF BOTANY.

and South Sea Islands, and the kernels of the seeds of the two
species of Magonia indigenous to Brazil. The latter plants also
yield a poisonous nectar and the root-bark is used in the poison-
ing of fish. A shellac is obtained from Schleichera trijuga of
India and the seeds of this plant yield " marcassa oil."

Paullinia Cupana is a woody climber indigenous to and culti-
vated in Northern and Western Brazil. The leaves are alternate
and 5~foliate, the leaflets being oblong, acuminate, coarsely, irreg-
ularly dentate, and with short stalks ; the flowers are yellow and
in axillary panicles ; the fruit is a 3-locular, 3-seeded sub-drupose
capsule (Fig. 332).

i. BALSAMINACE^E OR JEWEL-WEED FAMILY.—
The plants are succulent herbs with alternate, petiolate leaves and
conspicuous axillary flowers ; the fruit is a capsule which at
maturity breaks into five valves, discharging the seeds with con-
siderable force.

The balsam of the gardens (Impatiens Balsamina), which
flowers all summer, belongs to this family. Other species of
Impatiens are also cultivated.

The stem sap as well as that of the flowers of a number of
species of Impatiens is used on account of its red and yellow
coloring matters, to color the skin of the hands and feet as also, the
nails by the people of India, Tartary and Japan. The seeds of
some species of Impatiens yield an oil which is used for burning.

XVIII. ORDER RHAMNALES.

This order includes two large families which are characterized
by having 4 or 5 stamens which are either alternate with the sepals
or opposite the petals when the latter are present. The ovules
are atropous.

a. RHAMNACE^E OR BUCKTHORN FAMILY.— The
plants are woody climbers, shrubs or small trees.

Rhamnus Purshianus is a large shrub or small tree. The leaves
are petiolate, oblong, elliptical, acuminate, finely serrate and pubes-
cent beneath ; the flowers are small and in axillary umbellate
cymes, and the fruit is 3-lobed, black, ovoid, and drupaceous.
The bark constitutes the official Cascara sagrada (Fig. 333).

Rhamnus Frangula or Alder Buckthorn is a shrub the botan-

CLASSIFICATION OF ANGIOSPERMS. 605

ical characters of which closely resemble those of R. Purshianus.
The bark of this plant is also official.

FIG. 333. A Cascara tree on University of Washington campus. — After Johnson and
Hindman, Amer. Jour. Pharm., 1914, p. 389.

The leaves of the shrub known as New Jersey Tea (Ceanothus
americamts) are said to have been used as a substitute for tea
during the Revolutionary times. This plant is found in the East-

606 A TEXT-BOOK OF BOTANY.

ern United States and Canada and the root, which contains con-
siderable tannin and possibly an alkaloid, has been used in medi-
cine. The leaves of Sageretia theezans of Asia have also been
used as a substitute for tea. A number of plants of this family
have been SUBSTITUTED FOR HOPS in the fermentation industry, as
Ceanothus reclinatus of the West Indies ; Colubrina fermenta of
Guiana, and Gouania doming ensis of Martinique and Hayti.
Saponin is found in the bark of Gouania tomentosa of Mexico.
A crystalline bitter principle, colletin, occurs in the wood of Col-
letia spinosa of South America. The bark of Discaria febrifuga
of Brazil has been used as a substitute for cinchona. A number
of genera furnish fish poisons, as Zizyphus, Tapura, and Gouania.
Gum-lac is formed on the twigs of Zizyphus Jujuba of Asia as
the result of the sting of an insect (Coccus lacca).

The fruits of several species of Zizyphus, thorny shrubs found
growing in South America, are edible and enter into the French
or Spanish confection known as JUJUBE-PASTE.

b. VITACE^: OR GRAPE FAMILY.— The plants of this
family are woody climbers or erect shrubs with alternate, petiolate
leaves, and small, greenish, regular flowers, the fruit being a
berry.

The most important genus, economically, is Vitis, to which
belong the cultivated grapes, the fruits of which furnish raisins,
wine and brandy. The GRAPE-VINE indigenous to Europe (Vitis
vinifera) is cultivated in all temperate and sub-tropical countries,
and the variety silvestris which is found distributed in the Medi-
terranean countries as far east as the Caucasus Mountains is sup-
posed to have furnished the cultivated wine grape. The CONCORD
and CATAWBA GRAPES are cultivated varieties of the northern Fox-
or Plum-grape (Vitis Labrusca) indigenous to the Northern
United States east of Minnesota. The DELAWARE GRAPES are cul-
tivated varieties of the frost-grape (V. cordifolia) and the sweet-
scented grape (V. vulpina) of the Eastern United States. The
pulpy part of the grape contains from 9 to 18 per cent, of grape-
sugar and 0.5 to 1.36 per cent, of tartaric acid. In unfavorable
seasons the tartaric acid is replaced in part by malic acid. The
soil has a marked influence on the quality of grapes, a sandy soil

CLASSIFICATION OF ANGIOSPERMS. 607

producing a light colored wine, a soil rich in calcium a sweet
wine, and a clay soil a fine bouquet, etc.

WINES are made by fermenting the grape juice, and contain
from 5 to 20 per cent, of alcohol, from i or 2 to 12 per cent, of
sugar, about 0.5 per cent, of tartaric, acetic and other fruit-acids,
tannin and coloring matter from a trace to 0.3 per cent., and
various compound ethers, giving them their characteristic flavors
or bouquets. WHITE WINES are made from the juice of the pulp
of the white or colored grapes after separation from the epicarp
and seeds. In the manufacture of RED WINE no care is taken to
separate the seeds and skins of colored grapes or even the stems
on which the fruits are borne. PORT WINE is made from a grape
grown in Portugal, the wine being chiefly exported from Oporto.
The term CLARET is applied to a red wine containing a small
amount of alcohol. BRANDY is obtained by the distillation of the
fermented juice of the grape. CHAMPAGNE is a product obtained
by fermenting grape juice to which other substances have been
added, and contains about 10 per cent, of alcohol and 67 per cent,
of carbon dioxide. RAISINS are obtained from a variety of Vitis
vinifera containing a high percentage of sugar. In the prepara-
tion of raisins the ripe grapes are dried either by exposure to the
sun or artificial heat. In grape preserves in addition to the indis-
tinguishable cells of sarcocarp, raphides of calcium oxalate occur.

A principle resembling toxicodendrol is found in Vitis incon-
stans of Japan. A greenish-blue coloring principle occurs in Vitis
sicyoides of South America. The leaves and twigs of VIRGINIA
CREEPER or American ivy (Psedera quinquefolia) contain tartaric
acid, glycollic acid, catechin and inosit.

XIX. ORDER MALVALES.

This order includes several families having rather diversified
characters. The stamens are numerous, the sepals are valvate
and the placentas are axillary.

a. FAMILY EL^OCARPACE^.— The members of this
family are shrubs or trees mostly indigenous -to the Tropics.
They are distinguished from the plants of the other families of
this order in not containing lysigenous mucilage canals. A prin-
ciple yielding hydrocyanic acid is found in Echinocarpus Sigun

6o8

A TEXT-BOOK OF BOTANY.

FIG. 334. American Linden, Basswood or Lime tree (Tilia americana}. A, flowering
branch showing the obliquely heart-shaped, serrate leaves with conspicuous midrib and
primary veins, and cymose clusters of yellowish-white fragrant flowers, which are at-
tached to the midvein of an oblong, leaf-like bract. B, several of the ovoid or spherical,
nut-like fruits about the size of peas. — From Bulletin 26, U. S. Department of Agriculture.

of Java. A yellow coloring principle is found in the leaves of
Vallea cordifolia of Peru. A fatty oil is found in the seeds of
several species of Elceocarpus. A number of fruits of this family

CLASSIFICATION OF ANGIOSPERMS. 609

are edible. Maqui Fruit is obtained from Aristotelia Maqui of
Chile and is used to color wine. The seeds of Sloanea dentata are
eaten like chestnuts in Guiana.

b. TILIACE^E OR LINDEN FAMILY.— The plants are
shrubs or trees with alternate, simple leaves, and with white
flowers in cymes or panicles. In the Linden or Basswood ( Tilia)
the peduncles are partly adnate with the long, leaf-like bracts.
The fruits are dry drupes (Fig. 334).

The flowers of the European Linden (Tilia europcca) contain
a fragrant volatile oil and are used in medicine. The flowers of
other species of Tilia also contain volatile oils, and the flowers of
Tilia toment-osa of Southern Europe are used to flavor champagne.
The leaves of Tilia europcea contain the glucoside tiliacin. Sev-
eral species of Grewia are used as fish poisons. A purgative
principle is found in the seeds of Cor chorus olitorius of Southern
Asia, Africa and South America. A bitter principle occurs in
the seeds of Cor chorus tridens of Arabia, India and Egypt. A
reddish-colored, fatty oil known as APEIBA OIL is obtained from
the seeds of Apeiba Tibourbon of Guiana. The root of Grewia
scabrophylla is used as a substitute for Althaea in India. Mucilage
is found in the flowers and fruits of a number of genera. The
leaves of Corchorus siliquosus are used in Panama as a substitute
for tea. A number of the fruits of this family are edible, as of
Muntingia and Apeiba. The bast fibers of several species of Cor-
chorus, particularly C. capsularls of China and India, constitute
jute, which is used in the making of cordage. The fiber is sep-
arated by cold retting in stagnant water.

c. MALVACE^ OR MALLOW FAMILY.— The plants are
mostly herbs or shrubs with alternate, simple leaves, and regular,
perfect, large flowers, with the stamens united into a column which
encloses the styles (Fig. 222, E), and a capsular fruit. The culti-
vated ornamental Hollyhock and Althaea belong to this family.

Althcea officinalis or marshmallow is a perennial herb about
I M. high with broadly ovate, petiolate, acute, dentate and lobed,
pubescent leaves ; the flowers are 2 to 4 in number in the axils of
the leaves and have rose-colored petals. The bractlets are linear
and the fruit consists of 15 to 20 indehiscent carpels. The root
is used in medicine as a demulcent.
39

610 A TEXT-BOOK OF BOTANY.

GOSSYPIUM species. — The plants are herbs or shrubs with
3- to 5-lobed leaves, and large axillary flowers; the fruit is a
5-locular, dehiscent capsule or pod ; the seeds are spherical or
somewhat angular and covered with long i -celled hairs, which]
latter constitute cotton- (Fig. 139).

FIG. 335. Indian mallow, velvet leaf (Abulilon Theophrasti). A common plant grow-
ing in waste places, with velvety, heart-shaped leaves; yellow flowers; and characteristic
fruits, consisting of 12 to 15 beaked carpels. — After Brown.

There are three important cultivated species. ( i ) SEA ISLAND
COTTON is obtained from Gossypium barbadense, a plant which is
principally cultivated in the Southern United States and also in
Northern Africa, Brazil, Peru and Queensland. This species is
distinguished by the fact that after removal of the hairs from

CLASSIFICATION OF ANGIOSPERMS. 611

the seeds they are smooth. (2) G. arboreum has purplish-red
flowers, yields a particularly white cotton, and is cultivated in
Egypt, Arabia and India. (3) G. herbaceum is distinguished by
its broadly lobed leaves and yellowish flowers. This plant has
been cultivated for over 26 centuries in Arabia and the East
Indies, and since 1774 in the United States. Of this latter species
there are a number of cultivated varieties. The bark of the root
constitutes the cotton-root bark of medicine.

The seeds of the genus Gossypium contain a large percentage
of fixed oil, which is obtained by expression and is official as
COTTON SEED OIL. The residue is known as cotton seed oil-cake,
and contains a considerable amount of proteins with a small quan-
tity of oil and a poisonous principle, ricin. A fat resembling .that
of Cacao is obtained from the seeds of Pachira macrocarpa of
Brazil ; Kapak oil is derived from the seeds of Eriodendron anfrac-
tuosum caribccum of the West Indies.

The flowers of some of the members of the Malvaceae contain
coloring principles, and have been used for dyeing, as Hollyhock
(Althaa rosea) and Mallow (Malva sylvestris). MUSK SEED or
Amber seed, which is used in perfumery as a substitute for musk,
is obtained from Abelmoschus moschatus indigenous to the East
Indies and now cultivated in other tropical countries. Malva mos-
chata also has the odor of musk, and is found in Middle and
Southern Europe.

Saponin is found in the roots of Sida jamaicensis and Hibiscus
Sabdariffa of the East and West Indies ; Sida paniculata of Peru
is used as an anthelmintic and the action is supposed to be due
to the glandular hairs. The seeds of several members of this
family are used as substitutes for coffee, as Abutilon muticum of
Egypt, and Okra or Gumbo (Hibiscus esculentus). The leaves
of Sida canariemis and 5\ retusa, the latter of India, have been
substituted for tea leaves. The fruits of several of the members
of this family are edible, as Hibiscus esculentus, which yields the
vegetable okra, and H. ficulneus of Ceylon and Egypt, which are
used like beans.

Fibers are obtained from a number of the other members of
this family, as the bast fibers of Hibiscus tiliaceus of the Tropics,
H. cannabinus of the East Indies, Urena lobata, Abutilon indicum,

j6i2 A TEXT-BOOK OF BOTANY.

Sida retusa, and Napcca Iccvis, all cultivated more or less in tropical
countries.

d. FAMILY BOMBACE/E.— This is a group of tropical
trees yielding a variety of useful products. A gum is obtained
from Bombax malabaricum, and mucilage is contained in the genus
Ochroma and several species of Bombax. The root of Bombax
malabaricum contains tannin in addition. The bast fibers of a
number of the plants of this family are used like cotton in making
fabrics, as species of Bombax, Chorisia and Adansonia. The
fruits of several of the Bombacese contain tartaric acid, as the
Sour Cucumber tree or CREAM-OF-TARTAR TREE (Adansonia Greg-
orii) of Northern Australia; and the MONKEY-BREAD TREE or
BAOBAB (Adansonia digitata) of India and South America, which
attains a diameter of 9 M. The green fruit of Matisia cordata
of the Andes region is edible. The seeds of Bombax insigne and
Matisia Castano of South America yield a product on roasting
which is used like cacao bean. The seeds of Cavanillesia umbel-
lata of Peru are edible and contain a considerable quantity of
fixed oil.

e. STERCULIACE^: OR COLA FAMILY.— The plants
are herbs, shrubs or trees, sometimes lianes, with mostly simple,
petiolate, alternate leaves ; the flowers are small and form a
rather complex inflorescence.

Theobroma Cacao is a small tree 5 to 10 M. high, with cori-
aceous, glaucous, entire leaves, and clusters of brownish 5-mer-
ous flowers arising from the older branches or stem ; the fruit is
large, fleshy, ovoid, 10- furrowed longitudinally, yellow or reddish,
and contains five rows of seeds, 10 or 12 in each row (Fig. 336).
The seeds are ovoid, somewhat flattened, and with large, convo-
luted cotyledons which break up into more or less angular frag-
ments on drying. The seeds contain 35 to 50 per cent, of a fixed
oil known as CACAO BUTTER and official as Oleum Theobromatis ;
15 per cent, of starch; 15 per cent, of proteins; I to 4 per cent,
of theobromine; 0.07 to 0.36 per cent, of caffeine, about 0.5 per
cent, of sugar, and also a small amount of tannin. The red color
of the seed is due to a principle known as cacao-red which is
formed by the action of a ferment on a glucoside.

The Cacao tree is indigenous to the countries bordering the
Gulf of Mexico and is now cultivated in many tropical countries.

CLASSIFICATION OF ANGIOSPERMS.

613

FIG. 336. Cacao tree (Theobroma Cacao), growing in Rio Hondo, Costa Rica. In
the illustration is shown the peculiar habit of this tree in producing large, ovoid, fleshy
fruits on the main axis or trunk, as well as on the older branches. When Cortez conquered
Mexico he found the Aztecs using Cacao seeds to make a beverage; this was later introduced
into Europe, previous to either coffee or tea. — Reproduced by permission of The Phila-
delphia Commercial Museum.

614

A TEXT-BOOK OF BOTANY.

FlG. 337. A flowering branch of the Kola nut tree (Cola acuminata), growing in Trini-
dad. The leaves are obovate or lanceolate, acuminate, and in the axils are borne small
clusters of purplish flowers. The tree is indigenous to Africa and is extensively cultivated
in the West Indies and Brazil, in which countries it has become naturalized. — Reproduced
by permission of The Philadelphia Commercial Museum.

CLASSIFICATION OF ANGIOSPERMS. 615

Most of the cacao of the market is obtained from Ecuador (the
Guayaquil variety being especially valued), Curasao, Mexico,
Trinidad, and the Philippine Islands. The seeds of the wild
plants contain a bitter principle, the quantity of which is found
to be greatly reduced in the plants when under cultivation. The
bitter principles in the raw product are more or less destroyed
by the process of fermentation to which the seeds are subjected
in preparing them for use, which at the same time develops the
aroma.

Cola acuminata is a tree with lanceolate or obovate, acuminate,
entire, petiolate leaves. The flowers are purplish, unisexual, and
in small axillary clusters, frequently arising from the old wood ;
the fruit consists of five follicles, each containing 4 to 8 seeds.
The seed is made up of two large, fleshy cotyledons. They have
much the same constituents as Cacao, but the proportions of these
differ (Fig. 337). The leaves of Waltheri'a glomerate, are used
as a hemostatic in Panama like matico, as are also the leaves of
Pterospermum acerifoliuvn. The inner bark of Fremontia
calif ornica is used for purposes similar to those of elm bark.
Mucilage is also found in the following genera : Pentapetes, Wal-
theria, Guazuma, Relict eres, and Sterculia. Tannin is found in
the bark of Guazuma uhnifolia of South America. An oil is manu-
factured from the seeds of Sterculia fcctida of the East Indies
and Cochin China. The seeds of a number of species of Sterculia
are edible. Abronia angusta of India yields a fiber which has
been suggested as a substitute for silk.

XIX. ORDER PARIETALES.

This is a group of plants of rather wide distribution, and
includes perennial herbs like the violets; evergreen shrubs, such
as the Tea Plant ; and vines like the Passion flower. As the name
indicates, the plants of this order are characterized by the flowers
having, for the most part, ovaries with parietal placentas.

a. FAMILY DILLENIACE^.— The plants are mostly trop-
ical trees which yield valuable timber. The wood of a species of
Dillenia growing in the East Indies also contains red coloring
substances. The fruits of Dillenia indica contain citric acid and
are used like lemons. The leaves of Curatella americana contain
considerable silicon and are used to polish wood. Dillenia speciosa

6i6

A TEXT-BOOK OF BOTANY.

FIG. 338. Leaves, flowers, and fruits of the Tea plant (Thea sinenis, or Camellia
viridis). The plant is a shrub or small tree bearing lanceolate, evergreen leaves, and in
the axils occur the rather large, white, fragrant flowers. The fruits are small, globular
capsules. — Reproduced by permission of The Philadelphia Commercial Museum.

of India contains a large percentage of tannin. Some species of
Dillenia are cultivated and the foliage and flowers combine to
make the plants the most beautiful in the plant kingdom.

b. MARCGRAVIACE;E.— The members of this family are

CLASSIFICATION OF ANGIOSPERMS. 617

partly epiphytic, and have dimorphic leaves, the smaller ones being
pitcher-like. The plant which is cultivated in greenhouses, Marc-
gravia uinbellata, is used in the Antilles in medicine.

c. THEACE;E OR TEA FAMILY.— The plants are shrubs

or trees with alternate, evergreen leaves, and perfect, regular

FIG. 339. Picking tea on a plantation in Japan, the wall at the left probably being
the ruins of an ancient temple. While the plant ordinarily is a shrub, it is kept trimmed
and is a bush from 2 to 5 feet high. The plants begin to bear in the third year, and continue
to yield a commercial article from 3 to 7 years thereafter. The number of crops per year
is determined by the geographical location. In the tropical fields of Ceylon, India, and
Japan leaves are picked frequently, while in northern Japan they secure only one crop a
year. — Reproduced by permission of The Philadelphia Commercial Museum.

flowers with numerous stamens, occurring one or more in the
axils of the leaves. The fruit is a 3- to 5-locular, dehiscent
capsule. The most important member of this family is Thca
sinensis, the two varieties viridis and Bohea furnishing the leaves
known as TEA. The Tea tree is indigenous to Eastern Asia, and is
now extensively cultivated in China, Japan, India, Java, Brazil,
Sicily, Portugal and France, and to some extent in the Southern
United States (Figs. 338, 339).

618 A TEXT-BOOK OF BOTANY.

The fresh leaves of Thea do not have the properties which
characterize the commercial article, the aroma and other qualities
being developed after special treatment. Two general classes of
tea are found in commerce, these depending on the mode of treat-
ment. Those which are rapidly dried by means of artificial heat
constitute GREEN TEA. The leaves which are slowly dried, per-
mitting fermentation to set in, furnish BLACK TEA. Tea leaves
contain 1.5 to 3.5 per cent, of caffeine; theobromine and the-
ophylline (an isomer of theobromine) ; 10 to 20 per cent, of gallo-
tannic acid ; quercitrin, and a volatile oil containing, among other
components, methyl salicylate. The seeds contain about 30 per
cent, of fixed oil, I per cent, of caffeine, and saponin. The leaves
furnish one of the sources of the official caffeine. Saponin is
found in the seeds of Thea Sasanqua of China and Japan. Two
saponin-like substances (assamin and assaminic acid) are found
in the seeds of Thea assamica. The flowers of T. Sasanqua are
used in China and Japan to flavor teas. The flowers and leaves
of Thea kissi are used as an insecticide. The red colored sap of
Laplacea Hcematoxylon of New Granada is used in medicine.

d. GUTTIFER^ OR GAMBOGE FAMILY.— The plants
are principally shrubs and trees of the Tropics, that is, if we
exclude the Hypericaceae which are now put in a group by them-
selves.

Garcinia Hanburyi is a tree with ovate, petiolate, coriaceous,
opposite leaves. The flowers are small, yellow, dioecious, occur-
ring in small clusters in the axils of the leaves. The fruit is a
pome-like berry, with a papery endocarp and an oily sarcocarp,
and 3 or 4 seeds, i in each loculus (Fig. 340). The trees are
chiefly valued on account of the gum-resin known as gamboge
which they contain.

A resin used in making plasters is obtained from Calophyllum
brasiliense of Brazil. Balsams resembling Copaiba have been
obtained from Calophyllum Calaba of the West Indies. Balsams
known as TACAMAHAC are also derived from the following plants :
Bourbon Tacamahac from Calophyllum Tacamahaca, India Taca-
mahac from C. apetalum and Brazilian Tacamahac from Rheedia
Madruno. Balsams are also obtained from Caraipa grandiflora

CLASSIFICATION OF ANGIOSPERMS.

619

of Brazil, and Rheedia acuminata of Peru. Resins and balsams
are obtained from a number of species of Clusia.

A yellow coloring principle, mangostin, is obtained from the
bark and fruit of Mangosteen (Garcinia Mangostana) of the East
Indies. Yellow coloring principles are found in Ochrocarpos

FIG. 340. Gamboge plant (Garcinia Hanburyi). A branch showing the
axillary pistillate flowers and pome-like fruits. — After Baillon.

longifolius of India and Vismia acuminata of South America.
Tannin occurs in Mahurea palustris of. Brazil, Mesua ferrea of
the East Indies, that flower-buds of Ochrocarpos longifolius of
India, and several species of Cratoxylum of China and Java.

A butter-like fat is obtained from the seeds of Garcinia indica.
A fixed oil known as LAUREL-NUT OIL is derived from the seeds
of Calophyllum Inophyllum and other species of Calophyllum

620 A TEXT-BOOK OF BOTANY.

growing in the East Indies, Cochin China and Brazil, as well as
the seeds of Symphonia fasciculata of Brazil.

The bark of Clusia pseudochina is used in Peru as a substi-
tute for cinchona. An alkaloid is found in Visinia robusta of Java.
A gum is obtained from Calophyllutn tomentosum of India and
Vismia acunrinata, that of the latter being purgative. The flower
buds of the India Suringi (Ochrocarpos longifolius) have an
aromatic odor resembling cloves. Aromatic principles are also
found in other plants of this family.

Edible fruits are yielded by the following plants : MANGO
FRUIT from Garcinia Mangostana and other species of Garcinia;
MAMMEI APPLE or Apricot of St. Domingo from Mammea anier-
icana of tropical America, the latter being used in the prepara-
tion of Mammey wine or " Toddy " and a liquor known as " Eau
de Creole." The seeds of Platonia insignis are used like almonds
in Brazil and Paraguay ; the fruit of the latter plant is quite acid
and is eaten with sugar.

e. HYPERICACE^: OR ST. JOHN'S-WORT FAMILY.—
The plants are herbs or shrubs of the temperate regions, and are
represented in the United States by the Hypericums, which are
quite common. The flowers are characterized by the numerous
stamens which are united into distinct groups or clusters. The
flowers of Hypericum perforatum or Common St. John's-wort
contain yellow and red coloring principles. Yellow coloring prin-
ciples have also been isolated from Hypericum larici folium of
Ecuador and H. elodes of Northern Europe. The entire plant of
H. perforatum is used in medicine and contains considerable resin,
and a small amount of volatile oil.

/. FAMILY DIPTEROCARPACE^:.— The plants of this
family are principally trees and indigenous to tropical Asia. The
family derives its name from the winged fruits of the principal
genus Dipterocarpus. A number of economic products are fur-
nished by this group of plants. BORNEO CAMPHOR is obtained
from Dryobalanops aromatica. The camphor separates in canals
in the older parts of the wood and between the wood and bark,
and is obtained by felling the trees, splitting the wood, and then
removing the camphor by hand. Owing to the fact that some of
the trees do not contain camphor, it is sometimes necessary to fell

. CLASSIFICATION OF ANGIOSPERMS. 621

a hundred trees in order to obtain 6 or 8 K. of the product. The
young twigs of this plant as well as the older wood yield a volatile
oil known as Oil of Borneo camphor.

GURJUN BALSAM or Wood oil is obtained from a number of
species of Dipterocarpus growing in the East Indies by incising
the stems as in the collection of turpentine. The balsam is used
as a substitute for copaiba and contains an ethereal oil which
consists chiefly of a sesquiterpene, an indifferent resin, and gur-
junic acid. SINDOR BALSAM is obtained from Dipterocarpus mar-
ginatus of Borneo. A resin known as " PINEY RESIN," which is
used as a substitute for Dammar, is obtained from a number of
species of Vateria growing in India. CHAIA RESIN is obtained
from Shorea rubifolia of Cochin China. The bark of Shorea
robusta of Northern India contains 32 per cent, of tannin. The
seeds of species of Shorea, Pinanga, Gysbertsiana and Isoptera
yield the fatty oil known in Java as TANGKAWANG. The seeds of
a number of plants of this family contain considerable starch, as
Vateria, Vatica and Doona. The woods of the following genera
are extensively used : Vatica, Shorea, and Hopea.

g. FAMILY TAMARICACE^E.— The plants are halophytic
shrubs found in the desert regions of Central Asia and Mediter-
ranean countries and one genus (Fouquieria) is found in Mexico.
Fouquieria splendens is cultivated to some extent, and is known
as Ocotilla or Coach-whip Cactus. The bark contains gum, resin
and wax; the latter is known as OCOTILLA WAX and resembles
beeswax. The twigs of Myricaria germanica of Europe are used
as a substitute for hops. A manna-like sugar is formed on the
stems of Tamarix mannifera growing in Egypt, Arabia and
Afghanistan, as the result of the sting of an insect (Coccus manni-
parus). Tannin is found in a number of species of Tamarix as
well as in the galls formed on the plants, the tannin being used
for dyeing. A table salt is prepared from the ash of several
species of Reaumuria found in Northern Africa and the East
Mediterranean region.

h. FAMILY BIXACE;E.— These are shrubs or trees found
in the Tropics, and are of interest chiefly on account of the seeds
of Bixa Orellana which furnish the coloring matter known as
ANNATTO (Orlean, Arnotta). The plant is found in tropical

622 A TEXT-BOOK OF BOTANY.

America and also in Polynesia and Madagascar. The seeds are
covered with a fleshy arillus from which the coloring matter is
prepared by means of water. The insoluble matter is collected,
made into cakes and chiefly used for dyeing and coloring. Annatto
contains a red crystalline principle, bixin, a yellow coloring prin-
ciple, orellin, and an ethereal oil. The root of this plant also con-
tains some coloring matter. A yellow coloring principle is found in
Cochlospermum tinctorium of Senegambia and an aromatic resin is
obtained from Cochlospermum Gossypium of Ceylon and Malabar.

i. FAMILY CANELLACE^: OR WINTER AN ACE^.—
These are trees with aromatic barks having an odor of cinnamon ;
pellucid-punctate leaves; and golden-yellow flowers. The most
important member of this family is Winterania Canella growing in
the Antilles and in Southern Florida, which furnishes the CANELLA
BARK or False Winter's bark used in medicine. The bark occurs
in large quills or broken pieces, from 3 to 10 mm. thick, with the
periderm nearly entirely removed, the outer surface yellowish or
orange-red with transversely elongated patches of cork and shal-
low, whitish depressions ; the fracture is short with numerous resin
canals ; the odor aromatic ; taste aromatic, bitter and pungent. It
contains mannitol, resin and 0.5 to 1.28 per cent, of a volatile oil
containing eugenol, cineol, caryophyllene and pinene. The bark
of one or more species of Cinnamodendron of tropical America is
sometimes substituted for Canella bark, but it is distinguished by
containing tannin, which constituent is not found in Canella.

;. VIOLACE^: OR VIOLET FAMILY.— The plants are
herbs or shrubs with basal or alternate leaves, perfect, irregular
flowers, and 3-valved dehiscent capsules (Fig. 280, /). The best
known representatives of this group are the cultivated species of
the genus Viola, including the English or sweet violet ( Viola odor-
ata), which produces a volatile oil containing ionon ; and the varie-
ties of Viola tricolor vulgaris which furnish the pansies of the
garden. The entire herb of Viola tricolor has been used in medi-
cine and contains the yellow coloring principle viola-quercitrin,
salicylic acid and methyl salicylate (Figs. 201, 232).

k. FAMILY FLACOURTIACE^:. — These are tropical
shrubs and trees, and are chiefly of interest because of their valu-
able woods and acid, juicy fruits. A number of them are of

CLASSIFICATION OF ANGIOSPERMS. 623

medicinal interest. CHAULMUGRA OIL is said to be obtained from
the seeds of Gynocardia odorata of Farther India. The seeds also
contain gynocardic acid and hydrocyanic acid. The latter is also
present in the seeds of Hydnocarpus venenata of Southern India
and Ceylon and the leaves of Kiggelaria africana.

A number of species of Lcetia growing in Cuba yield a resin
resembling sandarac. The Coccos oil which is used in perfumery
is obtained from several species of Myroxylon growing in Poly-
nesia. The fixed oils from the seeds of Gynocardia odorata and of
several species of Pangium are used in cooking. A bitter principle
occurs in the bark of Casearia adstringens of Brazil. A purgative
principle is found in C. esculenta of tropical Asia and Australia.
The root of Homalium racemosum of Guiana contains an astrin-
gent principle.

/. FAMILY TURNERACE^.— These plants are herbs,
shrubs and trees mostly found in tropical America, and are of
interest on account of the leaves of Turnera diffusa, particularly
the variety aphrodisiaca, which yield the DAM IAN A of medicine
esteemed as a tonic laxative like Rhamnus Purshianus. The drug
usually consists of leaves, although the reddish stems, yellowish
flowers and globular capsules may be present. The leaves are
about 25 mm. long, varying from oblanceolate to obovate; the
margin is serrate-dentate; the color, light-green (older leaves
somewhat coriaceous and pubescent) ; the odor aromatic ; taste
aromatic and bitter. Damiana contains a volatile oil, resin, and
the bitter principle damianin. Ethereal oils are found in other
species of Turnera, and T. angustifolia of Mexico contains con-
siderable mucilage.

m. PASSIFLORACE^ OR PASSION-FLOWER FAM-
ILY.— The plants are mostly herbaceous or woody vines climbing
by means of tendrils, with alternate, palmately-lobed, petiolate
leaves and solitary, perfect, regular flowers. The flowers are
peculiar in that between the corolla and stamens there are numer-
ous, frequently petaloid, colored, sterile, filamentous bodies which
are known collectively as the " corona." The fruit is a berry or
dehiscent capsule. The genus Passiflora is known as the Passion-
flower because the flowers are considered to be emblematic of the
Crucifixion, the corona representing the crown of thorns, the

624 A TEXT-BOOK OF BOTANY.

stamens the nails, and the gynaecium with its three styles, the
three thieves. The rhizomes of the Passion-flowers of the South-
ern States (Passiflora incarnata and P. lutea) have been used in
medicine. Not much is known with regard to the active principles
of these two plants or of the thirty other species of Passiflora
which are used in medicine. The fruits of several species of Passi-
flora are edible, and a number of them are cultivated on account
of their beautiful as well as odorous flowers.

«. CARICACE^ OR PAP AW FAMILY.— This family is
composed of two genera of latex-containing trees growing in trop-
ical America, the best known of which is the genus Carica. The
Papaw or Melon tree (Carica Papaya) is a small tree with a
straight, slender, usually unbranched trunk which bears at the
summit a cluster of long-petiolate, deeply-lobed leaves. The
flowers are dioecious, and the fruit is a large, melon-like berry.
The green fruits as well as the leaves contain a milk-juice which
is obtained by incising them. The material is dried and is used
in medicine on account of its containing a proteolytic ferment,
papain or papayotin, which is active in the presence of both acids
and alkalies. The leaves and fruit also contain the alkaloid car-
paine, and in addition the leaves contain the glucoside carposid.
The root contains a glucoside somewhat resembling potassium
myronate and a ferment which has a decomposing action upon it.
A proteolytic ferment is also present in the leaves of Carica quer-
cifolia of Argentina. The melon tree is cultivated on account of
the fruits, which are edible.

o. BEGONIACE^:.— This is a family of tropical plants which
are extensively cultivated. They are herbs or shrubs frequently
with tuberous rhizomes and with characteristic, asymmetric, varie-
gated leaves. They are easily propagated by cuttings, providing
they have sufficient moisture, even the leaves giving rise to new
plants. The roots of Begonia anemonoides of South America and
B. gracilis of Mexico contain purgative principles. Calcium oxal-
ate and acid oxalates are found in the leaves of probably all of the
species of Begonia. The roots of a number of species of this
genus are astringent.

p. DATISCACE^E.— The plants are trees or shrubs found
principally in the Tropics. A bitter principle is found in the

CLASSIFICATION OF ANGIOSPERMS. 625

Yellow hemp (Datisca cannabina) of Southern Europe and the
Orient. The root contains a yellow coloring principle, datiscin,
which is used in the dyeing of silk. The wood of Octoineles and
Tetramelcs is used in the making of tea-chests.

XXI. ORDER OPUNTIALES.

The plants of this order are succulent, with much reduced
leaves, and with flowers characterized by having a perianth with
numerous segments and an inferior ovary.

a. CACTACE/E OR CACTUS FAMILY.— This is a remark-
able family of succulent plants growing largely in the arid regions
of Mexico, Brazil and other parts of America. The stems are
more or less flattened, terete or tuberculated, in some cases becom-
ing branched and woody. The leaves are reduced to scales, but
are sometimes larger, more or less cylindrical or dorsiventral, and
usually drop off sooner or later. In the axils of the leaves or
leaf-scars there are usually groups of hairs and spines. The
flowers are mostly solitary, sessile, perfect, regular and conspic-
uous. The fruit is usually a fleshy berry, the fruits of a number
of species being edible.

Quite a number of the Cacti have been used in medicine, the
one most commonly employed being the NIGHT-BLOOMING CEREUS
(Cereus grandifiorus) , which is extensively cultivated on account
of its flowers. The flowers and fresh stems are the parts used.
They contain several acrid principles, including probably an alka-
loid and a glucoside, the drug resembling in its action digitalis.

MESCAL BUTTONS (Anhalonium) are the dried tops of several
species of Lophophora growing in Northern Mexico. The main
axis of the plant is under the ground and produces at certain
points small aerial shoots which are more or less button-shaped
or disk-like, being about 20 to 50 mm. in diameter. In the center
of the disk occur tufts of hairs which vary in the different species,
and among which are usually found one or more pinkish flowers.
The drug has been used like Night-blooming Cereus, and con-
tains several alkaloids, namely, anhalonine (similar to pellotine),
mescaline, anhalonidine and lophophorine. Alkaloidal principles
are also found in other members of this family.

The sap of several species of Cereus of the Antilles has anthel-
40

626

A TEXT-BOOK OF BOTANY,

FlG. 341. Prickly Pear or Indian Fi'g (Opuntia vulgaris), a prostrate, more or less
spreading cactus, composed of flattened stems bearing very small, awl-shaped and decidu-
ous leaves and short, yellowish-green bristles and occasionally solitary spines. The flowers
are pale yellow, opening in the sunshine. The fruit is a succulent berry about 2.5 cm.
long. Various of these cacti are used as food by the cattle, which often eat them with the
bristles. Frequently the spines are burnt off by the cattlemen with the use of gasolene
torches, so as to prevent the accumulation of spines in the stomachs of the cattle in the form
of phyto-bezoars, which are globular accumulations of vegetable tissues. (See p. 577.)—
After Troth.

CLASSIFICATION OF ANGIOSPERMS. 627

mintic properties, as also that of certain species of Rhipsalis and
Opimtia. A caoutchouc-like exudation is obtained from Opuntia
vulgaris and other species of Opuntia growing in the West Indies.
An astringent principle is found in the root and bark of Opuntia
Karwinskiana of Mexico. A tragacanth-like gum is found in
Peireskia Guacamacho of Venezuela, Opuntia rubescens of Brazil
and O. Tuna of the West Indies, Mexico and South America. An
alcoholic beverage is made by the Indians of Sonora from the
fruit- juice of Cereus T lumber gii.

A number of species of Opuntia yield edible fruits. The
PRICKLY PEAR is the fruit of Opuntia Tuna growing in the West
Indies and tropical America ; INDIAN FIG is derived from Opuntia
Ficus-Indica growing in Southern Europe, particularly Sicily ; a
fruit also known as Prickly pear or Indian fig is derived from
Opuntia vulgaris, a common Cactus growing in sandy soil in the
Eastern United States. The COCHINEAL INSECT which is official
under the name of coccus in a number of pharmacopoeias (Coccus
Cacti) feeds upon various of the Cactacea, more especially the
Nopal plant, Nopalea (Opuntia) coccinellifera, a native of Mex-
ico and Peru. (See Kraemer, Amer. Jour. Pharm., 1913, p. 344-)

XXII. ORDER MYRTALES OR MYRTIFLOR^.

The plants are herbs or shrubs with complete flowers, rarely
apetalous, producing one or more ovules in each loculus.

a. THYMEL^ACE^: OR MEZEREUM FAMILY.— The
characters of this family are illustrated by the Spurge laurel or
Mezereon (Daphne Mezereum), which is a small shrub about I M.
high, with oblong-lanceolate, acute, entire, sessile leaves, and small
groups of fragrant flowers, the perianth tube of which is purplish-
red or white. The fruit is an ovoid, reddish drupe. The bark of
Daphne Mezereum and other species of Daphne is used in
medicine.

The bark of Funifera utilis of Brazil contains a vesicating
principle. A principle with similar properties is found in the
bark of Leather wood (Dirca palustris) of the Eastern United
States and Canada. The fruit and leaves of Gnidia carinata of
Cape Colony contain emetic and drastic principles. A poisonous
principle is found in Pimelea trichostachya of Australia. A

628 A TEXT-BOOK OF BOTANY.

yellow coloring principle is found in several species of Daphne
and Thymelcua. The wood of Aquilaria Agallocha of India and
China is aromatic and resembles the " Aloe wood." A balsam is
obtained from the wood of Pimelea oleosa of Cochin China. The
bast fibers of quite a number of plants are used in the making of
paper, as of Daphne in India, Gnidia of Madagascar, Lagetta (L.
lintearia or Lace-tree) of Jamaica and St. Domingo, Thymelcua
of the Mediterranean countries and Linodendron of Cuba. The
fibers of Leather wood (Dirca palustris) of the Eastern United
States and Canada are said to be used in a similar manner.

b. FAMILY EL^EAGNACE^.— This is a small family
represented in the United States by several genera, among which
is the Buffalo berry (Lepargyr&a argentea), a thorny shrub found
in the western part of the United States and the Northwest Terri-
tory. The fruit is a reddish drupe-like berry which contains a
small amount of citric and malic acids, 5 per cent, of sugar, and
in composition is much like the currant. It is eaten by the Indians,
and used to a great extent in the Western States in the making
of jellies. The leaves and flowers of a number of species of
Elaeagnus are used in medicine.

c. LYTHRACE^E OR LOOSESTRIFE FAMILY.— The
members of this family are herbs, shrubs and trees usually with
opposite, entire leaves. The flowers are in racemes and the fruit
is a capsule. Quite a number of the plants yield valuable woods
and a number are cultivated as ornamental plants.

The flowers of Woodfordia floribunda of India contain a red
coloring principle, and the bark and leaves of Lafccnsia Pacari of
Brazil contain a yellow coloring principle. Considerable tannin
is found in the root of the Purple loosestrife (Ly thrum Salicaria)
of the Northern United States and Canada, and widely distrib-
uted in the Old World ; and also in the fruit of Woodfordia flori-
bunda, a plant which is extensively cultivated in greenhouses. A
bitter principle, nessin, is found in the leaves of Nescea syphilitica
of Mexico and probably other species of this genus. Cuphea
viscosissima of Mexico is said to. resemble digitalis in its physiologi-
cal action. A vesicating principle, resembling cantharidin in its
action, is obtained from the fresh leaves of Ammannia baccifera
of India. A narcotic principle is found in the seeds of Lager-

CLASSIFICATION OF ANGIOSPERMS. 629

strccmia Flos-regina of India. The flowers of Lawsonia inermis,
native to and cultivated in the Orient, have an odor resembling that
of the Tea rose. The shrub is also cultivated to some extent in
the West Indies and is known in the Orient as the HENNA PLANT.
The leaves are used in the preparation of the cosmetic Hinna.
They contain an orange or brownish-yellow dye which is used in
the dyeing of the skin and hair.

d. PUNICACE^: OR POMEGRANATE FAMILY includes
a single genus of two species. The Pomegranate (Punica grana-
tum) indigenous to the Levant and now extensively cultivated is
of chief interest. The plants are small trees, the young twigs of
which are 4-angled and frequently thorn-like. The leaves are
opposite, ovate-lanceolate, entire and short-petiolate. The torus,
calyx and corolla are scarlet, and the gynsecium consists of two
whorls of carpels. The fruit is an inferior edible berry with a hard
pericarp or rind. The pulpy portion is formed from the outer
layer of the seed-coat. The bark of the root and stem is used in
medicine (see Granatum, Vol. II). The rind of the fruit is used as
an astringent because of the tannin which it contains. It does not
appear, however, to contain the alkaloids found in the official bark.

e. FAMILY LECYTHIDACE^.— The plants are mostly
shrubs and trees indigenous to the Tropics. They are of chief
interest on account of the BRAZIL-NUT (Fig. 342) obtained from
Bertholletia excelsa, and the Sapucaya-nut obtained from the
Monkey-pot tree (one or more species of Lecythis), both genera
of South America. The seeds (so-called nuts) are rich in oil
and proteins and are edible. The fruit of Careya arborea is drupa-
ceous and is also edible, the seeds being considered, however,
to be poisonous. Bitter narcotic or poisonous principles are also
found in the fruit of Planchonia valida of the Molucca Islands and
the seeds of a number of species of Lecythis. The fruits and roots
of a number of species of Barringtonia are used in China and Java
to stupefy fish. The pericarp of the fruit of Fcetida moschata
of Guiana contains considerable quantities of an ethereal oil. The
flowers of Grids cauMora of the Antilles are used like tea. A
cooling drink is made from the sarcocarp of Couroupita guianensis
of the West Indies and Guiana

630

A TEXT-BOOK OF BOTANY,

/. RHIZOPHORACEyE OR MANGROVE FAMILY.—
These are tropical shrubs or small trees with evergreen, cori-
aceous leaves, small cymose and axillary flowers, and seeds which
germinate while the fruit is still attached to the plant. The best

FIG. 342. Brazil-nut (also known as Para nut, cream nut, and nigger-toe), the seeds
of Bertholletia excelsa, a Brazilian tree belonging to the Fam. Myrtaceae. In the illustration
is shown a portion of the fruiting branch with some of the long, leathery leaves. The fruits
terminating the branches are woody, vary from 10 to 15 cm. in diameter, and are in the
nature of a pyxis, — i.e., opening by means of a lid. It encloses about 20 brownish-gray,
3-sided seeds, which are largely exported from Para. — Reproduced by permission of The
Philadelphia Commercial Museum.

known genus of this family is Rhizophora (Mangrove tree), of
which there are three species, the AMERICAN MANGROVE being R.
Mangle. This tree produces aerial roots on the stems and branches,
and leaves which are characterized by a number of layers of

CLASSIFICATION OF ANGIOSPERMS. 631

water-containing cells. The plants grow in muddy swamps, or
along the sea-coast where the water is brackish, a number together
forming the so-called " Mangrove swamps " (Fig. 165).

The root and bark of the Mangrove, as well as other species
of Rhizophora and several species of Bruguiera, contain a large
quantity of tannin which resembles catechu. The aerial roots of
Rhizophora are used by the natives of Polynesia in the making of
bows, and the woods of several genera are used in carpentry.

g. MYRTACE^E OR MYRTLE FAMILY.— This is a group
chiefly of shrubs and trees, some, as of species of Eucalyptus,
being the loftiest trees known, attaining a height in some instances
of 105 M. The plants are indigenous to Australia and tropical
America and some are extensively cultivated.

EUCALYPTUS species. — The leaves frequently vary in shape and
in arrangement on the young and older branches of the same
plant. On the young branches they may be, as in Eucalyptus
Globulus, ovate or broadly elliptical, opposite and sessile, while
on older branches they are scythe-shaped, glandular-punctate,
glabrous, petiolate and alternate. In the latter case the petioles
are twisted and the leaves stand edgewise so that both surfaces are
equally exposed to the light and hence of similar structure. The
flowers are solitary, or in cymes or umbels, occurring in the axils
of the leaves. Petals are wanting and the whitish stamens, which
are numerous and inflexed in the bud, are covered by an oper-
culum or lid which is considered to be formed by the union of
the sepals, and which dehisces on the maturing of the stamens,
this being one of the most characteristic features of the genus.
The fruit is a 3- to 6-locular truncated capsule or pyxis.

This is a very important genus from an economic point of
view, among the products being the volatile oil (oil of eucalyptus),
and eucalyptol, both of which are official, and the tannin or
so-called " gum," known as Eucalyptus kino.

Jambosa Caryophyllus (Eugenia caryophyllata). — This is a
small tree indigenous to the Molucca Islands and now extensively
cultivated in the Tropics. The leaves are opposite, ovate-lance-
olate, acuminate, petiolate, entire and evergreen. The flowers are
rose-colored and in cymes ; the fruit is berry-like and constitutes
the Anthophylli or MOTHER-CLOVE. The unexpanded flower-buds

632 A TEXT-BOOK OF BOTANY.

constitute the drug or spice known as Cloves. (See Vol. II.)

Pimento, officinatis is a tree with opposite, lanceolate, acute,
petiolate, pellucid-punctate and evergreen leaves. The flowers are
small, white and in axillary racemes. The fruit, known as " All-
spice," is used for flavoring.

Not only are ethereal oils obtained from the genera Euca-
lyptus, Jambosa and Pimenta already described, but also from
other members of the Myrtacese. OIL OF BAY or oil of Myrcia
is distilled from the leaves of Pimenta acris of the West Indies.
The oil consists largely of eugenol, methyl-eugenol, chavicol,
methyl-chavicol, citral, phellandrene and myrcene, and is used
in the preparation of BAY RUM. The fruits of P. acris yield 3.3
per cent, of an oil resembling the leaf oil.

Cheken leaves are obtained from Eugenia Chekan. They are
about 25 mm. long, ovate or rectangular, with entire, somewhat
revolute margin, light green, pellucid-punctate, aromatic, astrin-
gent and bitter. Cheken leaves yield about i per cent, of a volatile
oil containing cineol and pinene; 4 per cent, of tannin; a volatile
alkaloid and a glucoside.

Oil of Cajeput is obtained from the leaves and twigs of Mela-
leuca Leucadendron, particularly the varieties Cajeputi and minor
of the East Indies. The principal constituents of this oil are
cineol, terpineol, pinene, and a number of aldehydes and acid
esters. An oil resembling Cajeput oil is obtained from the leaves
and flowers of Myrceugenia camphorata of Chile.

The leaves of Myrtus communis, a plant extensively cultivated
in the Mediterranean countries of Europe, yield a distillate with
water known as EAU D'ANGE and used as a toilet article.

The leaves of the following plants are used as substitutes for
tea leaves: Myrtus Molina oi Chile, Melaleuca genistifolia of
Australia, and Leptospermum scoparium and other species of this
genus growing in New Zealand. The seeds of Eugenia disticha
are known in the Antilles as Wild coffee. Quite a number of the
genera of this family yield edible fruits. GUAVA or Guayava fruit
is obtained from Psidium Guajava of tropical America. ROSE
APPLE is the fruit of Jambosa malaccensis, growing in the East
Indies and Oceanica. JAMBUSE BERRIES are derived from Jambosa
vulgaris which is extensively cultivated in the Tropics. The

CLASSIFICATION OF ANGIOSPERMS. 633

lemon-like fruit of Myrcia coriacea is used in medicine, the bark
in tanning, and the wood in dyeing. The fibrous bark of Eugenia
ligustrina is used like oakum.

h. FAMILY COMBRETACKE:.— The members of this fam-
ily are shrubs or trees, sometimes climbing ; with usually alternate,
petiolate, simple leaves ; sessile flowers in racemes ; somewhat
fleshy, winged, i-seeded fruits, and are mostly found in the
Tropics.

Like the Fagacese the plants of this family contain a tannin,
similar to gallotannic acid, in nearly all parts of the plant. The
MYROBALANS of the East Indies are the young fruits of Terminalia
Chebula. The pericarp contains from 5 to 45 per cent, of tannin,
the latter amount being found in the fruits known as Long or
Chebula Myrobalans. The fruits also contain ellagic and chebu-
linic acids. The fruits of Terminalia Bellerica constitute the Bel-
eric Myrobalans. The galls of Terminalia macroptera of Africa
and other species of Terminalia as well as of Bucida Buceras of
tropical America are particularly rich in tannin. A yellow coloring
principle is found in Terminalia Brownii of Africa and is used in
dyeing leather. The bark of T. Catappa of Asia and Africa is used
to dye leather black.

A gum-resin with cathartic properties is obtained from Termi-
nalia fagifolia of Brazil. An aromatic resin is found in Ter-
minalia angustifolia of the East Indies. The fruits of one or
more of the Combretacese are said to be used in the preparation
of the arrow-poison of the Negritos. The seeds of Terminalia
Catappa and Combretum butyrosum contain about 50 per cent.
of fixed oil. These seeds as well as those of other species of
Terminalia and Quisqualis indica of Farther India and tropical
Africa are edible. The seeds of the latter plant when unripe are
said to be used like mustard. The woods of a number of the plants
of the Combretacese are valuable for building purposes, and some
of the genera furnish ornamental plants which are cultivated in
greenhouses.

i. FAMILY MELASTOMATACE^E.— This is a large family
of herbs, shrubs, and trees with opposite, 3- to Q-nerved leaves
and regular, perfect, often showy flowers. They are chiefly found
in South America and are represented in temperate regions by

634 A TEXT-BOOK OF BOTANY

the Meadow beauty (Rhexia). Quite a number of the plants are
cultivated and a large number yield edible fruits. The fruits,
barks and leaves frequently contain COLORING PRINCIPLES. A yel-
low coloring principle is found in the leaves of a number of species
of Memecylon of the East Indies and Africa, which resembles
that of saffron and curcuma. Red coloring principles are found
in the berries of a number of species of Blakea of South America.
A black coloring principle is obtained from the fruit of several
species of Tamonea of tropical America, Melastoma malabathri-
cum of the East Indies and Tococa guianensis of Northern South
America and Tibouchina Maximiliana of Brazil. Tannin is found
in considerable quantity in the barks of Tibouchina, Dissotis and
Rhynchanthera.

The leaves of Tamonea thewzans are used in Peru as a sub-
stitute for tea. A mucilage is found in the bark of Medinilla
crispata of the Molucca Islands. The flowers of the latter plant
as well as of M. macrocarpa are used as a remedy for the bite of
poisonous serpents.

;. ONAGRACE^: OR EVENING PRIMROSE FAMILY.
— These are mostly annual or perennial herbs with usually entire
or toothed, simple leaves. The flowers are perfect, regular or
irregular, epigynous, variously colored, solitary in the axils of the
leaves or in somewhat leafy spikes. The fruit is a dehiscent
capsule, berry, drupe, or nut. This family is represented in tem-
perate regions by such plants as the Willow herb (Epilobium),
Evening primrose (QEnothera), on which de Vries has carried on
his famous mutation experiments, and Enchanter's nightshade
(Circsea). The cultivated FUCHSIA also belongs to this family.
A yellow coloring principle is obtained from the herb and unripe
fruits of Jussieua pilosa of Brazil. The roots of (Enothera bien-
nus, O. muricata and other species of this genus are edible.

This family also includes the group of aquatic plants, repre-
sented by a single genus and one o*f which, Trapa natans or Water
chestnut, is naturalized to some extent in the ponds of Massachu-
setts and New York. The fruit is coriaceous, 2- to 4-spinose, and
i -seeded. The cotyledons are unequal, rich in starch, and are
edible, sometimes being ground and made into bread by the people
of Europe and Northern Asia.

CLASSIFICATION OF ANGIOSPERMS. 635

FIG. 343. Evening Primrose (CEnothera biennis), a simple, sometimes more or less
branching herb growing to a height of 3 to 15 dm. The leaves are lanceolate or oblong-
lanceolate; the flowers are symmetrical, with yellow petals; and the capsules are narrow
and 4-valved. This plant is one of the commonest of the CEnotheras, growing in open places.
It is a biennial like the other species, but it is possible for horticulturists to develop its life
history in one year. — After Brown.

636 A TEXT-BOOK OF BOTANY.

XXIII. ORDER UMBELLALES OR UM BELLI FLOR.E.

The plants of this order are widely distributed in northern
temperate regions, although there are some representatives in the
Tropics. The flowers are small, 4- or 5-merous and epigynous.

a. ARALIACE^E OR GINSENG FAMILY.— The plants
are mostly trees or shrubs with alternate, petiolate, simple or 3- to
/-compound leaves. The flowers are either in umbels or panicles.
The fruit is a drupe or berry. The best known representatives of
this family are the English ivy (Hedera Helix) of Europe, and
Ginseng (Panax quinque folium) (Fig. 345) growing in the East-
ern and Central United States. This plant is the source of the
ginseng root of commerce, considerable quantities of which are
exported to China, where it is used like the root of Panax Ginseng,
a plant growing wild in Manchuria and Korea. Both plants are
also cultivated in the United States, the roots from the wild plants
being preferred. The root contains a volatile oil, and considerable
starch. Several species of Aralia are used in medicine (Fig. 344).

The leaves of the English ivy contain the glucoside helixin,
and a carbohydrate, inosit. They also contain formic, oxalic, malic,
tannic and hederic acids, besides the yellow principle carotin. The
fruits of the ivy contain a purplish-red coloring substance and are
said to be poisonous.

The Chinese RICE PAPER is made from the pith of Tetrapanax
papyriferum, which grows wild in Formosa and is extensively
cultivated in China. .The pith is cut spirally into thin strips, which
are spread out flat and then cut into pieces varying from 15 to
30 cm. long and 10 to 12 cm. broad. This paper differs from
other papers in that it is a natural product.

The rhizome of Panax rep ens, growing in Japan, contains 20.8
per cent, of a non-toxic saponin with hemolytic properties.

b. UMBELLIFER^E OR CARROT FAMILY.— The plants
are herbs, frequently with hollow stems ; alternate, simple or com-
pound leaves, the base of the petiole often forming an inflated
sheath ; and small white, yellowish, greenish or somewhat purplish
flowers occurring in simple or compound umbels. The fruit is a
cremocarp, having characters which are of important taxonomic

CLASSIFICATION OF ANGIOSPERMS. 637

value, as the presence or absence of secondary ribs, number and
position of the vittse, etc.

FIG. 344. Wild Sarsaparilla (Aralia nudicaulis). The plant produces a long, cylin-
drical rhizome at or near the surface of the ground, and sends out at various points a single,
long-stalked compound leaf, and a shorter, naked scape bearing 2 to 7 umbels of greenish-
' white flowers. The rhizome is sold as American Sarsaparilla, but it has none of the con-
stituents of the true Sarsaparilla. — After Brown.

Coriandruni sativum is an annual herb the fruits of which are
official. The compound leaves are bi- or tri-pinnate, the leaflets

638

A TEXT-BOOK OF BOTANY.

being narrow linear-lanceolate ; and the flowers are white or rose-
colored.

FIG. 345. Panax quinquefolium (Ginseng): A, upper portion of plant showing pal-
mately-compound leaves with long-stalked leaflets and the berry-like drupes; B, fusiform
root; C, roots showing characteristic stem scars at the upper portion. — From a photograph
by Wyss. (See also Fig. 166, p. 305.)

Conium maculatum or Poison Hemlock is a tall, erect, branch-
ing, biennial plant, with purplish spotted stems, .large pinnately

CLASSIFICATION OF ANGIOSPERMS. 639

decompound leaves and small, white flowers (Figs. 346, 347).
The fruit as well as the leaves is used in medicine.

Carum Carvi (Caraway) is a biennial herb with bi- or tri-
pinnate, deeply incised leaves, and white flowers. The fruit is
official and the leaves are also used in medicine.

Pimpinella Anisum is a small, hairy, annual herb. The leaves
are variable, the lower being somewhat cordate and serrate, the
middle distinctly lobed, and the upper ones trifid ; the flowers are
white. The fruit is official and is also used for flavoring.

Fceniculum vulgar e is an annual or perennial, glabrous herb
with very finely dissected leaves, the divisions being narrow-linear.
The flowers are yellow, and the involucre and involucels are
wanting. The fruit is official.

Ferula fcctida is a stout, perennial herb with few, ternately
compound leaves and small, polygamous, light yellow flowers. The
root is rather large and yields the gum-resin asafetida. Asafetida
is also derived from other species of Ferula.

Ferula Sumbul is a tall perennial herb with purplish latex-
containing stems. The basal leaves are ternately compound and
with amplexicaul base. The leaves decrease in size from the base
upward, becoming bract-like near the inflorescence. The flowers
are polygamous, resembling those of F. fcetida. The root is official
and is probably also obtained from other closely, related species of
Ferula.

A large number of the plants belonging to the Umbelli ferae
contain essential oils, resins, gum-resins and related substances.
The gum-resin AMMONIAC is an exudation found on the stem and
branches of Dorema Ammoniacum and other species of Dorema
as a result of the sting of an insect. The plant is found in Western
Asia. The gum-resin occurs in yellowish-brown, globular, or
somewhat flattened tears which are brittle, milky-white internally,
with a distinct balsamic odor and bitter, acrid, nauseous taste. It
contains a small quantity of volatile oil having the odor of Angelica.
AFRICAN AMMONIAC is obtained from Ferula tingitana growing
in Northern Africa and Western Asia.

The gum- resin GALBANUM is obtained by incising the root of
Ferula galbaniflua and other species of Ferula growing in the
Levant. Galbanum occurs in pale yellowish-brown agglutinated

A TEXT-BOOK OF BOTANY

FlG. 346. — Poison Hemlock (Conium maculatum), showing the spreading habit of the plant
and the prominent large compound umbels of flowers. — After Bornemann.

CLASSIFICATION OF ANGIOSPERMS.

641

FIG. 347. Conium maculatum, showing the large decompound leaves with pinnatifid
leaflets, and the compound umbels of flowers, with detached, enlarged views of umbels and
a compound- umbel.— rFrom Bulletin No. 26, U. S. Department of Agriculture.

The fresh juice of Conium maculalum was used in the preparation of the famous hemlock
potion which was employed by the Greeks in putting their criminals to death. This is not
the same plant under the name of Conium which is referred to in Roman and mediaeval Latin
literature, the latter being Cicuta virosa, which does not grow in Greece and in Southern
Europe.

642

A TEXT-BOOK OF BOTANY.

V; St

FIG. 348. Cicuta maculata (Water Hemlock): A, upper part of stern with leaves and
compound umbels; B, base of the stem and the thick tuberous roots; C, cross-section of
stem showing part of a mestome-strand and the pith with secretory cells (a), vessels (v),
libriform (St), pith (p); D, a flower showing petals with long inflexed summit and the five
stamens inserted on the disk that crowns the ovary; E, the fruit; F, fruit in longitudinal
section showing the two ovules; G, cross-section of a mericarp showing the six vittae or oil-
tubes. — After Holm.

tears, forming a more or less hard mass, which 'is brittle when
cold but soft and sticky at 37° C. ; the odor is distinct, balsamic ;
the taste bitter and acrid. It contains from 10 to 20 per cent, of a
volatile oil composed of d-pinene, cadinene, and other principles.

CLASSIFICATION OF ANGIOSPERMS. 643

A volatile oil, known as AJOWAN OIL, and containing thymol,
is obtained from the fruit of Carum Ajowan of Europe, Asia and
Africa. A volatile oil containing APIOL is found in the fruit and
leaves of the garden parsley (Petroselinum sativum). DILL OIL
is obtained from the garden Dill (Anethum graveolens}. The
fruit of Sweet cicely ( Washingtonia longistylis) yields a volatile
oil known as sweet anise oil, which contains anethol. The oil
of water fennel ((Enanthe Phellandrium) contains about 80 per
cent, of phellandrene. CUMIN OIL is obtained from Cuminum
Cyminum of Turkestan and Egypt, and contains cymene.

The roots of a number of the plants of this family contain
volatile oils, as Lovage (Levisticum officinale) of Southern
Europe; European angelica or garden angelica (Angelica Arch-
angelica) ; American angelica or the purple-stemmed angelica
(A. atropurpurea) found in the Northern and Eastern United
States and Canada; Wild angelica (A. sylvestris) of Europe.

r. CORNACEyE OR DOGWOOD FAMILY.— The plants
are shrubs or trees with simple, opposite leaves, and flowers in
cymes or heads, which in the case of the Flowering dogwood
(Cornus florida) are subtended by four large, petal-like, white, or
pinkish bracts. The fruit is a I- or 2-seeded drupe.

The bark of Cornus florida, a shrub or small tree growing in
the United States, contains a bitter principle, cornin ; and a small
quantity of gallic and tannic acids.

Aucuba japonica, a plant indigenous to the Himalayas, China
and Japan and extensively cultivated on account of its crimson
berries, contains a glucoside aucubin. It is found in the different
varieties and varies in amount from 0.31 to 1.96 per cent.

METACHLAMYDE^E OR SYMPETAL.E.

This is the highest group of plants and is marked by the follow-
ing characters : The corolla is sympetalous ; the flowers are mostly
perigynous or epigynous and both the corolla and stamens are
borne on the perianth tube. The number of parts is definite, there
being 5 sepals, 5 petals, 5 or 10 stamens and 2 or 5 carpels. This
sub-class includes but six orders, to which, however, belong a large
number of medicinal and economic plants.

644 A TEXT-BOOK OF BOTANY.

I. ORDER ERICALES.

The plants of this order are distinguished by the fact that the
stamens are mostly free from the perianth tube.

a. PIROLACE^E. — The plants are small, mostly evergreen
perennials, and are represented in the United States by several
genera.

Chimaphila umbellata (Prince's pine or Pipsissewa) is a small
trailing or creeping plant producing distinct flower- and leaf-
branches. The 'leaves are used in medicine. The flowers are in
small corymbs and the petals are white or pinkish. In Chimaphila
maculata the leaves are lanceolate, mottled with white along the
veins and the flowers are considerably larger.

With the Pirolaceae are sometimes grouped the saprophytic
plants of the genus Monotropa. There are two representatives of
this genus which are common in the United States, namely, Indian
pipe (Monotropa uniflora) and false beech-drops (M. Hyp opitys).
The latter contains a glucoside or an ester of methyl salicylate, and
a ferment gaultherase (Fig. 349).

b. ERICACEAE OR HEATH FAMILY.— This is a large
family and the plants are widely distributed, especially in the
northern mountainous parts of both the Eastern and Western Con-
tinents. They vary from perennial herbs to trees. The flowers
are usually regular, the stamens being mostly 2-spurred (Fig.
221, S), and the fruit is either a superior or inferior drupe or
berry (Fig. 280, H).

Arctostaphylos Uva-Ursi is a low branching shrub which trails
or spreads on the ground. The leaves are used in medicine (Fig.
355). The flowers are small, white or pink, few and in short
racemes. The fruit is a red, globular drupe.

Trailing arbutus (Epigcca re pens) is a trailing, shrubby, hairy
plant with broadly elliptical or ovate, coriaceous, evergreen leaves
and white or rose-colored, fragrant flowers which are either per-
fect, with styles and filaments of varying length, or dioecious. The
leaves contain similar constituents to those in Uva-Ursi and
Chimaphila (Fig. 353).

The leaves of wintergreen (Gaultheria procumbens) are the
source of true oil of wintergreen, which consists almost entirely

CLASSIFICATION OF ANGIOSPERMS.

645

FIG. 349. Indian Pipe (Monotropa uniflora), a parasitic plant of the Ericaceae growing
on roots of various plants and on decomposing vegetable matter. The stems are white, or
yellowish-red, furnished with scales or bracts in place of leaves, and surmounted usually'
with a single nodding flower becoming in fruit erect. — After Troth.

646

A TEXT-BOOK OF BOTANY.

FIG. 350. Purple Azalea or Pinkster Flower (Rhododendron nudiflorum), showing the
upright lower stalk surmounted by several spreading branches, each bearing a number
of showy tubular flowers at its extremity. The flowers of this plant often appear before
the leaves.

CLASSIFICATION OF ANGIOSPERMS.

647

of methyl salicylate. It contains a small quantity of an alcohol
and an ester giving the characteristic odor. The same principles

FIG. 351. Great Laurel or Rose Bay (Rhododendron maximum), an evergreen shrub
found in low woods and along streams, chiefly in the mountains of the eastern United States,
often forming impenetrable thickets. It is one of the most beautiful of the flowering shrubs,
producing from scaly, cone-like buds numerous corymbose clusters of flowers varying from
pale rose to white. — After Troth.

probably also occur in several other species of Gaultheria (Fig.
354).

648

A TEXT-BOOK OF BOTANY.

FIG. 352. Mountain Laurel (Kalmia latifolia). This is a handsome evergreen shrub
growing on rocky hills and in damp soils in the eastern United States. The foliage is bright
green, and the showy flowers occur in terminal corymbs, being either of a whitish or pink
• color. The leaves of many species of Kalmia are said to be poisonous to animals, which is
especially true of the Sheep Laurel, known as Lambkill (Kalmia anguslifolia), which is
not infrequent on hillsides and pastures. — After Troth.

The poisonous principle andromedotoxin is found in a number
of species of Rhododendron, Leucothoe, and Pieris. This principle
is a powerful emetic and one of the most toxic principles known.

CLASSIFICATION OF ANGIOSPERMS. 649

FIG. 353. Trailing Arbutus or Mayflower (Epigcea repens). This is one of the first
of the early spring flowering plants. It is a prostrate woody plant, usually more or less
covered up with the autumn leaves and with rounded and heart-shaped evergreen leaves.
The flowers occur in small axillary clusters, are of a rose-red color, dimorphic as to styles
and stamens, and are very fragrant. They are transplanted with difficulty, and require
an acid soil, as do many other Ericaceae. — After Troth.

650

A TEXT-BOOK OF BOTANY.

FIG. 354. Wintergreen, teaberry (Gaultheria procumbens), a low shrub producing slender
stems lying at or beneath the surface of the earth and having ascending flowering branches
rising to a height of 7 to 12 cm. The leaves are evergreen, obovate or oval, and very spar-
ingly toothed; the flowers are whitish, urn-shaped and axillary. The fruit is capsular, sur-
rounded by the fleshy calyx, which forms the reddish aromatic globular berries. — Bureau
of Plant Industry, U. S. Department of Agriculture.

CLASSIFICATION OF ANGIOSPERMS. 651

FIG. 355. Bearberry (Arctostaphylos Uva-ursi), a trailing, shrubby plant with thick
evergreen, alternate leaves and whitish flowers in terminal racemes. The fruit is a globular,
reddish, berry -like drupe about the size of a pea, with a mealy, insipid pulp. A . alpina, grow-
ing in the Alpine summits of Maine and New Hampshire, develops a blackish drupe with a
juicy and edible pulp. — Bureau of Plant Industry, U. S. Department of Agriculture.

652

A TEXT-BOOK OF BOTANY.

FIG. 356. Black or High-bush Huckleberry (Gaylussacia baccala or G. resinosa). An
erect shrub with straggling branches, having leaves and flowers that are densely covered
with resinous dots; the leaves vary from oval to oblong; the flowers are reddish-yellow,
clustered in short racemes on terminal and axillary branches; the fruit is a sweet, blackish,
berry-like drupe. In some varieties it is smooth and shiny, in others it is bluish and covered
with a bloom. — After Brown.

CLASSIFICATION OF ANGIOSPERMS.

653

It probably occurs in the nectar of the flowers of Kalmia and
Rhododendron, being the cause of the poisonous properties of the
honey from this source. The leaves of several species of laurel

FIG. 357- Dwarf Blueberry or Early Sweet Blueberry (Vaccinium pennsylvanicum') .
A low shrub growing to a height of 2 to 6 dm. The leaves are lanceolate or oblong, of a
bright green color and minutely serrate with bristle-pointed teeth; the flowers are few, in
short racemes, the corolla being whitish and cylindrical; the berries are bluish, covered with
a bloom, and ripen during July and August. — After Brown.

v( Kalmia) contain considerable quantities of this principle, and
are poisonous to cattle.

The plants of the genus Gaylusaccia are small shrubs distin-
guished by having an inferior, berry-like drupe with ten loculi.
To this genus belong the huckleberries, as black huckleberry

654

A TEXT-BOOK OF BOTANY.

(G. baccata) ; blue huckleberry (G. frondosa) ; and dwarf huckle-
berry (G. dumosa). The latter plant grows in sandy swamps
in both the United States and Canada and the fruit ripens in
May and June. The fruits of the other two species ripen in July
and August (Fig. 356).

X«

FIG. 358. Low Blueberry or Blue Huckleberry (Vaccinium vacillqns'). A small
shrub with yellowish-green branchlets having nearly entire, narrow, obovate leaves. The
flowers are in racemose clusters, appearing before the leaves are half grown, as shown in
the illustration; the corolla is pinkish-white, oblong-cylindrical, and somewhat constricted
at the throat. The berries are blue, covered with a bloom, and ripen in August and Sep-
tember.— After Brown.

The plants belonging to the genus Vaccinium vary from very
small shrubs to tree-like shrubs and the fruit is an inferior,
5-locular berry with numerous seeds. The blueberries or bilberries
(whortleberries) are the fruits of several species of Vaccinium.

CLASSIFICATION OF ANGIOSPERMS.

6SS

The low-bush blueberry (V . pennsylvanicum) yields the berries
which ripen in June and July, while the high-bush blueberry ( V.
corymbosum) furnishes the fruits which are found in the market
in July and August (Figs. 357, 358).

FIG. 359. Small Cranberry (Vaccinium Oxycoccos). A trailing evergreen shrub, which
produces slender erect or ascending branches with oblong revolute leaves, rose-colored
nodding flowers, and a 4-locular, reddish, acid fruit. The berry of the American Cranberry
(V. macrocarpon) is much larger and furnishes the fruit of the market. There are many
varieties in cultivation. — After Brown.

The bilberry of Europe, Vaccinium Myrtillus, a plant growing
in Northern Europe and Asia and the Western United States and
Canada, is said to destroy Bacillus typhosus and B. Coli, an
infusion of the dried berries being used for this purpose. The
leaves of this plant contain ericolin and kinic acid.

656 A TEXT-BOOK OF BOTANY.

Cranberry is the fruit of several species of Vaccinium which
are sometimes grouped in a separate genus, Oxycoccos. There
are two principal species : The large or American Cranberry ( V .
macrocarpon) in which the berries are ovoid or oblong and the
small or European Cranberry ( V. Oxycoccos) in which the berries
are globose. The berries contain from 1.4 to 2.8 per cent, of citric
acid; and a bitter glucoside, oxycoccin (Fig. 359).

Many attempts have been made to cultivate the blueberry,
trailing arbutus, and other plants of the Ericaceae. For some
years a number of the agricultural experiment stations in the
United States have attempted to grow the blueberry as a fruit,
but none of these attempts has resulted in the commercial success
of blueberry culture, and the experimental results have been chiefly
of a negative character. The reason for this has been due, as
pointed out by Coville (Bull. No. 193, Bureau of Plant Industry,
U. S. Department of Agriculture), to a misunderstanding of the
soil requirements for this plant. Plants will thrive only in soil
having the following properties : I. The soil must have a distinctly
acid reaction, such as is found in peat bogs or on the surface of
the ground in sandy, oak, or pine woods. 2. Aeration of the soil
is necessary. The rootlets of the swamp blueberry are remarkable
in having no root hairs whatsoever, so that their absorptive surface
is only about one-tenth that of other plants having root hairs.
The growth of the rootlet of the blueberry is much less than that
of other plants, being about at the rate of only I mm. per day under
favorable conditions. The rootlets of healthy blueberry plants are
inhabited further by a mycorrhizal fungus which apparently has
the property of assimilating nitrogen.

II. ORDER PRIMULALES.

Of the three families belonging to this order, there are two
which are to some extent represented in temperate regions.

a. PRIMULACE^: OR PRIMROSE FAMILY.— The plants
are mostly perennial herbs with perfect regular flowers, and capsu-
lar fruits. The family is chiefly of horticultural interest, as it
contains the genera Primula and Cyclamen. There are several
species of Primula cultivated, and they are among the most popular
and beautiful of the florist's flowers (Fig. 360). Several of the

CLASSIFICATION OF ANGIOSPERMS.

657

FIG. 360. Primula (Primula obconica), one of several species of Primula which are
cultivated in greenhouses and as house plants. The leaves are circular heart-shaped,
long petiolate, and very hairy; the flowers are pinkish or lilac color and occur in umbels.
The hairs of this plant are very irritating, and cause a dermatitis similar to that produced
by poison ivy. — After Guernsey.

species are found in Northern United States and Canada. Dur-
ing recent years it has been reported that the wild primrose (P.
farinosa) and also the cultivated species (P. obconica) possess
42

658 A TEXT-BOOK OF BOTANY.

hairs which are very irritating and cause a dermatitis similar to that
produced by poison ivy.

A number of the primulas have been examined chemically.
The subterranean parts of Primula officinalis contain two crystal-
line glucosides, primeverin and primulaverin, which by the action
of the ferment, primeverase, produce an anise-like odor. The
odors of the other species of Primula are probably due to distinct
glucosides: (a) one producing an anise-like odor, as in P. ofUci-
nalis, P. capitata, and P. denticulata; (b) one producing the odor
of methyl salicylate, as in P. longiflora, P. elatior, and P. vulgaris ;
(c) one producing the odor of coriander, as in P. auricula, P.
panonica, and P. Palinuri. The flowers of a number of species
are light in color and somewhat luminous in the dark.

b. PLUMBAGINACE^E OR LEADWORT FAMILY.—
Perennial, mostly acaulescent herbs, growing in saline locations.
Sea lavender or marsh rosemary (Limonium carolinianum) is
found in the salt meadows from Labrador to Texas. The plant
is reported to contain tannin and has been used in medicine.

III. ORDER EBENALES.

This order includes three families which are chiefly indig-
enous to the Tropics. The leaves are alternate, and the flowers
vary in the different families, the fruit being a berry or drupe.

a. SAPOTACE^: OR SAPODILLA FAMILY.— The plants
usually have a milky latex, and many of them yield GUTTA-PERCHA,
of which the following may be mentioned: Palaquium Gutta, P.
oblongifolium, P. borneense and P. Treubii, all growing in the
East Indies. The latex is obtained by incising the trees and collect-
ing the exuding juice in suitable vessels. It soon coagulates and
forms grayish or reddish-yellow hard masses, which are plastic
at 65° to 70° C. Owing to the fact that the material is plastic
when heated and firm and tenacious when cold, it is used for a
variety of purposes, as in the manufacture of surgical instruments
and as a material for filling teeth. Gutta-percha as it exudes from
the tree is supposed to consist of a terpene-like hydrocarbon,
which on coagulation is oxidized, forming a number of resinous
compounds. The plants of other genera of this family also yield

CLASSIFICATION OF ANGIOSPERMS. 659

gutta-percha, as Mimusops Balata, M. Elengi, and about fifteen
species of Payena growing in the East Indies.

GUM BALATA is obtained from Mimusops Balata, a tree of
Guiana. The gum is more resinous and flexible than gutta-percha.
It contains /?-amyrin acetate and probably lupeol acetate.

A gum resembling gutta-percha is obtained from the Sabodilla
tree (Achras Sapota}. This gum is known in commerce as GUM
CHICLE and is obtained from Yucatan. It is whitish, brittle, and
yet somewhat elastic, aromatic, and contains 45 per cent, of a
colorless crystallizable resin, soluble in alcohol and ether; and 18
per cent, of caoutchouc. It is used in large quantities in the making
of chewing gum.

The seeds of Illipe butyracea yield a fixed oil which is known
as VEGETABLE BUTTER. A fixed oil is also obtained from other
species of Illipe as well as various species of Bassia, Argania, and
Butyrospermum, that from the latter being known as " shea
butter."

The family is notable on account of the hard woods, known as
IRONWOODS, which it furnishes, these being yielded by Mimusops
Kauki of Farther India and tropical Australia and Argania Side-
roxylon of Southwestern Morocco.

A number of species also yield highly prized edible fruits, as
the SAPOTILLA yielded by Achras Sapota indigenous to the Antil-
les and cultivated in tropical countries, and STAR APPLE yielded by
Chrysophyllum Cainito of tropical America.

b. EBENACE^: OR EBONY FAMILY.— The plants differ
from those of the preceding family in not containing a latex. The
flowers are monoecious or dioecious and they usually have from two
to eight styles. The chief interest is in the genus Diospyros, which
yields the wood known as EBONY. Black ebony is obtained from
various species of Diospyros growing in tropical Africa, and Asia,
and the Philippine Islands. White ebony is obtained from several
species of Diospyros growing in the Philippines. A red ebony is
obtained from D. rubra of Mauritius, a green ebony from D.
Chloroxyion of Farther India, and a striped ebony from several
species growing in the Philippines.

PERSIMMON fruit is obtained from Diospyros virginiana, a
tree growing from Rhode Island south to Texas. The astrin-

660 A TEXT-BOOK OF BOTANY.

gency of the unripe fruit is due to the tannin which it contains.
When it is ripe, which is not until after the appearance of frost,
it is palatable and contains considerable malic acid and sugars.
The Japanese persimmon is a cultivated variety of D. Kaki and
produces a large orange-colored fruit which is not uncommon in
the fruit markets in many parts of the world. At the present
time the plant is cultivated in California.

The bark of our native persimmon is used in medicine. It
contains considerable tannin which resembles gallotannic acid, and
a crystalline resinous principle with a peculiar odor and slightly
astringent taste.

c. STYRACACE^ OR STORAX FAMILY.— The flowers
of this family somewhat resemble those of the Ebenacese, but the
filaments of the stamens are united in a single series, and there
is a single slender style.

Styrax Benzoin is a medium-sized tree with long, ovate, acu-
minate leaves which are very hairy on the under surface. The
flowers occur in terminal racemes, and are silvery white on the
outer surface and reddish-brown on the inner surface. The bal-
samic resin yielded by this plant is official as benzoin.

IV. ORDER GENTIANALES OR CONTORTS.

The plants of this order have opposite leaves, the flowers are
regular and the gynaecium consists of two separate carpels. The
order includes five families, all of which furnish medicinal plants.

a. OLEACE^ OR OLIVE FAMILY.— This family is
chiefly of interest because of the olive and manna trees.

The olive tree (Olea europcea) is indigenous to the Orient and
is now cultivated extensively in Southern Europe, Northern
Africa, the islands of the Mediterranean, tropical America, includ-
ing the Southern United States, and in California. The leaves
are narrow-lanceolate, entire, coriaceous and evergreen. The
flowers are small, white, diandrous and in axillary racemes. The
fruit is a drupe, the sarcocarp of which is rich in a fixed oil
known as olive oil. The oil is obtained by expression, and is
official. Depending upon the character of the fruits and the
amount of oil which they yield, over forty varieties are recognized.

CLASSIFICATION OF ANGIOSPERMS. 661

The fresh green olives contain a glucoside oleuropein, which
disappears on the maturation of the fruit.

Fraxinus Ornus is a tree resembling the ash, with /-foliate
leaves, and polygamous flowers occurring in compound racemes.
The fruit is a flat samara with the wing at the apex. The sac-
charine exudation from this plant is official as manna.

The white ash (Fraxinus americana) is a valuable tree on
account of the timber which it yields. The bark contains a bitter
glucoside, f raxin, the solutions of which .are fluorescent ; a bitter
substance, f raxetin ; an ethereal oil of a butter-like consistency,
and tannin. Some of these principles are also found in other
species of Fraxinus growing in the United' States and Europe.

The bark of the fringe tree (Chionanthus virginica) of the
Southern United States contains an intensely bitter glucosidal
principle, chionanthin, and possibly also saponin.

The leaves of the garden lilac (Syringa vulgaris) contain a
crystalline glucoside, syringin, and syringopicrin, both of which
are probably also found in other species of Syringa as well as
the bark and leaves of privet (Ligustrum vulgar e), which latter
plant is extensively used for hedges.

b. LOGANIACE^E OR LOGANIA FAMILY.— The plants
are variable in character, being herbs, shrubs, trees or vines.

Yellow jessamine (Gelsemium senipervirens) is a twining
woody vine, sometimes trailing on the ground for a considerable
distance. The leaves are oblong-lanceolate and evergreen. The
flowers are bright yellow and dimorphic. The fruit is a septi-
cidally dehiscent capsule. The rhizome .and roots are official.

Carolina pink (Spigelia marilandica) is a perennial herb with
ovate-lanceolate, more or less acute and nearly sessile leaves.
The flowers are yellow on the inner and scarlet on the outer
surface, and occur in a I -sided spike or scorpioid cyme. The fruit
is a loculicidal, few-seeded, 2-valved capsule (Fig. 361). The
rhizome and roots are official.

Strychnos Nux-vomica is a small tree with broadly elliptical,
3- to 5-nerved, reticulately-veined, somewhat acuminate, cori-
aceous leaves. The flowers are whitish and in terminal cymes.
The fruit is a berry of varying size and contains several seeds,
the seeds being official. ;i ,1:.-:,

662

A TEXT-BOOK OF BOTANY.

CURARE, which is used by the Indians of South America as
an arrow-poison, is supposed to be made from the bark of Strych-
nos toxtfera, growing in Guiana, and probably other species of

FIG. 361. Carolina pink (Spigelia marilandica) showing the rhizome bearing two
branches with opposite leaves and flowers in terminal scorpioid cymes.

this genus. The active principle of this poison is the alkaloid
curarine, which when administered hypodermically has a powerful
action resembling that of digitalis.

CLASSIFICATION OF ANGIOSPERMS.

663

FIG. 362.' Closed Gentian (Gentiana Andrewsii), probably one of the most abundant
of the fall-flowering Gentians. It is a perennial, forming stout, leafy stems, terminated by
sessile clusters of blue flowers. The corolla is closed, and hence this Gentian is sometimes
called "Bottle Gentian." It grows in moist ground throughout most of the eastern United
States and Canada. — After a photograph by Troth.

c. GENTIANACEyE OR GENTIAN FAMILY.— The plants
are mostly herbs with regular, perfect, showy flowers occurring
usually in small cymes or racemes (Fig. 362).

Yellow gentian (Gentiana lutea) is a large, perennial herb

664 A TEXT-BOOK OF BOTANY.

(see Vol. II) with large, 5- to 7-nerved, broadly elliptical leaves.
The flowers are yellow and occur in axillary cymes. The fruit is
a 2-valved, ovoid capsule. The rhizome and roots are official.
Many of the gentians are among the most highly prized of the
wild flowers, some of them, as the fringed gentian (Gentiana
crinita), being one of the most beautiful. The closed gentian (Fig.
357) > s° called because the flowers remain closed, is quite abundant
in moist grounds throughout most of the United States and
Canada. The roots of a number of species of American gentian
have medicinal properties resembling that of G. lutea.

Menyanthes, the yellowish-white horizontal rhizome of Men-
yanthes trifoliata (Fig. 363), contains an amorphous glucoside
which is slightly soluble in water, soluble in alcohol, and is precipi-
tated with ta:nnm. Upon hydrolysis menyanthin yields a volatile
oil possessing an odor reminding one of bitter almonds.

SwertiaChirata. — The: entire plant is official.

HERBA QENTAURII MINORIS, the entire plant of Erythrcca Cen-
taurium of Europe, contains a glucoside, erytaurin, which forms
small colorless prismatic and bitter crystals and is slowly hydro-
lyzed by emulsin. ' S abb atia Elliot tii, occurring in the pine barrens
of the Southern States;\is known as the " quinine herb."

d. APOCYNACE/E Oil DOGBANE FAMILY.— The plants
vary from perennial herbs to shrubs and trees, contain an acrid
latex, and have flowers with the stigmas and styles united and the
stamens distinct. They are mostly found in the Tropics.

Apocynum cannabinum is a perennial herb with erect or ascend-
ing branches. The leayes are oblong-lanceolate, opposite, nearly
sessile or with short petioles (Figs. 226, 251). The flowers are
greenish-white, the lobes of the corolla being nearly erect and
the tube about as long as the calyx. The fruit is a slender, terete
follicle containing numerous seeds tipped at the micropylar end
with a tuft of hairs. The root is official.

The root of a closely related species, namely, spreading dog-
bane (Apocynum andros&mifolium), is sometimes substituted
for the official drug. The plant is distinguished by being more
spreading in its habit. The leaves are ovate (Figs. 226, 364), the
flowers are pinkish, the lobes being revolute, and the tube several
times as long as the calyx.

CLASSIFICATION OF ANGIOSPERMS. 665

FIG. 363. Buckbean or Bogbean (Menyanthes trifoliata), a perennial herb with a
fleshy horizontal rhizome, producing erect stems, bearing three oval or oblong leaflets,
and a raceme with numerous, white or rose-colored, fringed flowers. The plant grows in
bogs and shallow water in northern United States and Canada. — Bureau of Plant Industry,
U. S. Department of Agriculture.

666

A TEXT-BOOK OF BOTANY.

FIG. 364. Spreading Dogbane (Apocynum androsamifolium) , a perennial, branching
herb, with ovate-oblong, opposite leaves, and small, pinkish fragrant flowers occurring in
terminal cymes. All parts of the plants contain a white acrid latex. — After Brown.

Strophanthus Kombe. — The plant is a woody climber with
elliptical-acuminate, hairy leaves. The flowers are few, charac-
terized by long styles, and occur in axillary racemes. The fruit
consists of two long follicles containing numerous awned seeds,

CLASSIFICATION OF ANGIOSPERMS.

667

which are official. In the closely related plant S. hispidus the
flowers are numerous and occur in terminal cymes.

FIG. 365. Butterfly-weed or Pleurisy-root (Asclepias tuberosa), showing the sessile, oblong-
ovate leaves and the simple, many-flowered umbels.

QUEBRACHO or ASPIDOSPERMA is the bark of Aspidosperma
Quebracho-bianco, a tree growing in Argentine. It contains a
number of alkaloids and is used to some extent in medicine.

668 A TEXT-BOOK OF BOTANY.

The leaves and bark of the cultivated oleander (Nerium Olean-
der) contain the glucoside oleandrin, resembling digitalin in its
action ; a fluorescent principle, and probably several other
principles.

The common periwinkle (Vinca minor) contains the principle
vincin, which is supposed to be a glucoside and which probably
occurs in other species of Vinca.

e. ASCLEPIADACE^: OR MILKWEED FAMILY.— The
plants somewhat resemble those of the Apocynaceae. The flower,
however, is distinguished by having distinct styles, a 5-lobed
corona connecting the corolla and stamens, which latter are mostly
monadelphous, and pollen grains that are coherent, forming char-
acteristic pairs of pollinia. Few of the plants are of any economic
importance. The latex of the stems and the hairs of the seeds are
deserving of attention. PLEURISY ROOT, which was formerly offi-
cial, is obtained from Asclepias tuberosa, a plant growing in the
Eastern United States and one of the two members of this genus
that have orange-colored flowers (Fig. 365).

CONDURANGO is the bark of Marsdenia Cundurango, a liane of
Ecuador and Colombia. It occurs in quilled pieces, the bark
being from 2 to 6 mm. thick. Externally it is brownish-gray
and with a more or less scaly cork. The taste is bitter, acrid, and
aromatic. The drug contains an amorphous glucoside ; an unsatu-
rated alcohol occurring in large prisms; and a volatile oil (0.3
per cent.).

V. ORDER POLEMONIALES OR TUBIFLOR^.

This is a large order of plants, which are mostly herbaceous.
The leaves are either opposite or alternate ; the flowers are regular
or irregular, the stamens being usually adnate to the corolla.

a. CONVOLVULACE^: OR MORNING-GLORY FAM-
ILY.— The plants are mostly herbs or shrubs, frequently twining
(to the left). They are found mostly in the Tropics, but quite a
number of genera occur in temperate regions (Fig. 366).

Exogonium Purga is a perennial twining herb with distinctly
veined, cordate leaves ; purple flowers with the stamens exserted,
and occurring in cymes. The fruit is a 2-locular capsule. The

CLASSIFICATION OF ANGIOSPERMS.

669

plants produce slender rhizomes with tuber-like roots, these being
used in medicine.

Convolvulus Scammonia is a perennial twining herb, with a
large tap root, containing a resinous latex, and is the source of
the official scammony root. The leaves are sagittate ; the flowers
are large, yellowish- white and funnel- form, as in the morning-

FIG. 366. Great bind weed (Convolvulus sepium) showing trailing or twining habit,
the hastate leaves and funnel-shaped corolla. The plant is very resistant to noxious fumes
and is usually found in smelter regions.

glory, and occur in the axils of the leaves, either solitary or in
clusters. The fruit is a 4-seeded, 4-locular, dehiscent capsule.

A number of the plants of the Convolvulaceae are cultivated,
probably the most important of which is the SWEET POTATO vine
(Ipomoca Batatas}, a plant extensively cultivated in tropical and
sub-tropical countries on account of the edible tuberous roots.
The roots contain from 3 to 10 per cent, of sugar and 9 to 15 per
cent, of starch, which occurs in larger proportion in plants grown

670 A TEXT-BOOK OF BOTANY.

in sub-tropical countries. The starch is a commercial product
and is known as sweet-potato starch o-r BRAZILIAN ARROW-ROOT.
The grains are more or less bell-shaped and 2- or 3-compound,
about the size of wheat-starch grains, and in other ways resemble
those of tapioca.

To this family also belongs rather an interesting group of
parasitic plants, namely, dodder (Cuscuta). They contain the
principle cuscutin, and quite a number have been used in medicine.

b. POLEMONIACE^: OR POLEMONIUM FAMILY.—
A family mostly of herbs and chiefly of horticultural interest. It
contains the genus Phlox, which is indigenous exclusively to North
America. A number of the species are cultivated and are included
among the most valuable hardy, herbaceous perennials. The
flowers are among the most beautiful and persistent of our garden
plants. Another interesting genus belonging to this family is
Polemonium, a number of species of which have been long under
cultivation as border plants. Polemonium reptans is rather com-
mon in the woods of the Northern United States (Fig. 367).

c. HYDROPHYLLACE^E OR WATERLEAF FAMILY.—
The plants are herbs or shrubs which are indigenous to Western
North America. Very few of the plants of this family are of
use medicinally, although quite a number are ornamental plants.

Eriodictyon calif ornicum (E. glutinosum) or Yerba Santa
is a shrub growing in Northern Mexico and California. The
leaves are official (Fig. 368). The flowers are funnel-form, white
or purple, occurring in cymes. The fruit is a dehiscent capsule
and the seeds are small and few.

d. BORAGINACE^ OR BORAGE FAMILY.— The
plants are mostly herbs with regular blue flowers, occurring in
scorpioid inflorescence. The best examples of the group are
the forget-me-not (Myosotis), the roots of several species of
which have been used in medicine ; and the garden heliotrope
(Heliotropum peruvianum) , the fragrance of the flowers being
due to a volatile oil. This plant, as well as other species of
Heliotropum, contains a poisonous volatile alkaloid.

At one time considerable interest attached to ALKANET, the root
of Alkanna tinctoria of Southern Europe and Asia, on account
of the red coloring principle alkannin, which is soluble in alcohol,

CLASSIFICATION OF ANGIOSPERMS. 671

FlG. 367. Greek Valerian (Polemonium reptans), a perennial, 2 to 4 dm. in height, having
alternate pinnate leaves and light blue flowers in corymbs. — After Brown.

ether, fixed and ethereal oils, but insoluble in water. COMFREY
or SYMPHYTUM is the root of Symphytum officinale and other
species of this genus naturalized from Europe in waste places in
the United States. It occurs on the market in small, purplish-

672

A TEXT-BOOK OF BOTANY.

FIG. 368. Yerba Santa (Eriodictyon calif or m cum) , a low, evergreen, aromatic shrub,
the leaves and stems being covered with a resinous exudation. The leaves are lanceolate,
irregularly serrate or nearly entire, and woolly hairy beneath; the flowers are violet or
purple in color, and occur in cymose panicles. — Bureau of Plant Industry, U. S. Depart-
ment of Agriculture.

CLASSIFICATION OF ANGIOSPERMS. 673'

black, more or less curved pieces, which are quite mucilaginous
and astringent to the taste. The drug contains a gluco-alkaloid,
consolidin, and an alkaloid, cynoglossine. It also contains a small
amount of amylo-dextrin, i.e., starch which is not colored blue with
iodine, and tannin. The root and herb of HOUND'S TONGUE
(Cynoglossum officinale) are both used in medicine. The drug
contains the powerful alkaloid cynoglossine, which resembles cura-
rine in its action ; and the gluco-alkaloid, consolidin.

e. VERBENACE^: OR VERVAIN FAMILY.— The plants
are chiefly herbs or shrubs with usually opposite or verticillate
leaves and more or less irregular flowers (Fig. 369).

To* this family belongs the group of verbenas, some of which
are used in medicine, as blue vervain (Verbena, hastata), which
resembles eupatorium in its medicinal properties ; nettle-leaved
vervain (V. urticifolia) , which contains a bitter glucoside. The
drug LIPPIA MEXICANA consists of the leaves of Lippia dulcis
mexicana, and contains a volatile oil, the camphor lippiol, tannin,
and quercetin. Lippia citriodora, found growing in the central
part of South America, contains a volatile oil, of which citral is
a constituent. TEAK-WOOD, which is one of the hardest and most
valuable of woods, is derived from the teak tree (Tectona
gmndis), a large tree indigenous to Farther India and the East
Indies.

/. LABIATE OR MINT FAMILY.— The plants are mostly
aromatic herbs or shrubs, with square stems, simple, opposite
leaves, bilabiate flowers, and a fruit consisting of four nutlets.
The calyx is persistent, regular or 2-lipped and mostly nerved.
The corolla is mostly 2-lipped, the upper lip being 2-lobed or
entire, and the lower mostly 3-lobed. The stamens are adnate
to the corolla tube, and are either 4 and didynamous, or 2 per-
fect and 2 aborted. The ovary is deeply 4-lobed (Fig. 280, /).

The Labiatse are especially distinguished on account of the
volatile oils which they yield, and a few contain bitter or glucosidal
principles.

i. The following PLANTS ARE USED IN MEDICINE:

Scutellaria lateriftora (skullcap). The plant is a perennial
herb producing slender stolons somewhat resembling those of
43

674

A TEXT-BOOK OF BOTANY.

FIG. 369. Blue Vervain (Verbena hastata), a tall, perennial herb, with oblong-lanceolate
leaves, and numerous terminal spikes of violet-blue flowers. — After Brown.

CLASSIFICATION OF ANGIOSPERMS.

6/5

FIG. 370. Mad-dog Skullcap (Scutellaria later i flora), a perennial herb growing in
wet, shady places with an upright, quadrangular stem, bearing opposite ovate-oblong,
serrate leaves, in the axils of which are formed the blue bilabiate flowers. — Bureau of Plant
Industry, U. S. Department of Agriculture.

peppermint and spearmint. The stems are erect or ascending,
commonly branching and from 22 to 55 cm. high (Fig. 370).

676 A TEXT-BOOK OF BOTANY.

Marrubium vulgar e (white hoarhound) is a perennial woolly
herb with ascending branches; the leaves and flowering tops are
used in medicine.

Salvia officinalis or garden sage is a perennial, somewhat
shrubby, pubescent herb. The leaves are ovate, crenulate. The
flowers are bluish, somewhat variegated, the calyx and corolla
both being deeply bilabiate. Only the two anterior stamens are
fertile (bear anthers) ; the connective is transverse, the upper
end bearing a perfect pollen-sac, and the lower a somewhat
enlarged rudimentary pollen-sac (Fig. 223, F).

Hedeoma pulegioides (American pennyroyal) (Fig. 371).

MENTHA species. — The plants are nearly glabrous, diffusely
branching herbs, which form leafy stolons that are perennial
(Fig. 184). The leaves and flowering tops of both Mentha
piperita (Fig. 372) and Mentha spicata are official.

2. VOLATILE OILS of the following plants are official :

Rosmarinus officinalis is a shrub growing in the Mediterranean
countries. The plant has linear, coriaceous leaves, and bluish, bila-
biate flowers, the middle lobe of the lower lip of the corolla being
large, concave, and toothed on the margin. The flowering tops
yield from I to 1.5 per cent, of oil which is composed of 15 to 18
per cent, of borneol; about 5 per cent, of bornyl acetate; and
pinene, camphene, camphor, and cineol. There are two commer-
cial varieties of the oil, the Italian and French, the latter having
the finer odor.

Lavandula offlcinalis (garden lavender) is a shrub growing in
the Northern Mediterranean countries, as well as in England.
The leaves are linear, coriaceous ; the flowers are small, light blue,
bilabiate, with a tubular calyx, and occur in opposite cymes
(verticillasters).

The oil is derived from the fresh flowering tops, the flowers
yielding about 0.5 per cent. Two kinds of oil are on the market,
namely, French and English. The French oil contains 30 to 45
per cent, of 1-linalyl acetate; linalool; geraniol, both of which
latter constituents occur free and as esters. The English oil con-
tains about 5 to 10 per cent, of linalyl acetate and a slight amount
of cineol. Spike lavender (Lavandula Spica) is sometimes dis-
tilled with true lavender (see p. 679).

CLASSIFICATION OF ANGIOSPERMS.

677

FlG. 371. American Pennyroyal (Hedeoma pulegioides), a low, annual plant, growing
in dry soil; having small, opposite, elliptical leaves; and loose clusters of bilabiate flowers,
often forming terminal leafy racemes. — Bureau of Plant Industry, U. S. Department of
Agriculture.

Thymus vulgaris (garden thyme) is a small shrub having
linear or linear-lanceolate leaves, and pale blue flowers with

678

A TEXT-BOOK OF BOTANY.

strongly bilabiate, hairy calyx, and occur in axillary cymes. The
plant grows in the mountains of Southern France. The herb

FIG. 372. Peppermint (Mentha piperita): B, portion of shoot showing petiolate leaves;
C, transverse section of leaf showing several forms of glandular hairs on lower surface,
loose parenchyma (m) and palisade cells (p) ; D, lower surface of leaf showing stoma (s) and
glandular hair (g). Spearmint (Mentha spicatd) : A, portion of shoot showing flowers and
nearly sessile leaves; E, flower; F, outspread corolla showing cleft posterior lobe (p) and
the four adnate, included stamens; G, H, hairs from calyx; I, sphere crystals (sphaerites) of
a carbohydrate found in the corolla and style; J, pollen grains.

contains from 0.3 to 0.9 per cent, of volatile oil, which is of a
dark reddish-brown color, and contains from 20 to 25 per cent, of
thymol ; and cymene, 1-pinene, borneol and linalool. The Spanish

CLASSIFICATION OF ANGIOSPERMS. 679

oil of thyme contains from 50 to 70 per cent, of carvacrol, but no
thymol.

3. OF OTHER PLANTS OF THE LABIATE which are of interest,
the following may be mentioned :

Lavandula Spica yields oil of spike, which has an odor of
lavender and rosemary. The oil contains camphor, borneol, cineol,
linalool, and camphene.

Origanum Majorana (Sweet marjoram) is an annual culti-
vated herb that has more or less oval, entire leaves, white flowers,
and an aromatic odor and taste. It produces a volatile oil which
contains terpinene and d-terpineol. Origanum vulgar e (Wild
marjoram) grows in fields and waste places in the Eastern United
States and Canada. The calyx is equally 5-toothed and the
corolla varies from white to pink or purple. It contains a volatile
oil having an odor somewhat like that of the oil of O. Majorana.
Origanum hirtum and O. Onites yield an origanum oil containing
carvacrol and cymene. The oils obtained from Cretian Origanum
are the source of commercial carvacrol.

Pogostemon Patchouli, a plant cultivated in Southern China
and the East and West Indies, furnishes the oil of PATCHOULI
used in perfumery. Patchouly camphor and cadinene have been
isolated from the oil, but nothing, however, appears to be known
of the nature of the odorous principle.

Hyssopus officinalis (Garden hyssop) contains about 0.5 per
cent, of volatile oil to which the characteristic odor of the plant
is due. Satureia hortemis (summer savory) yields a volatile oil
containing carvacrol, cymene and terpene. Ocimum Basilicum
(Sweet basil) is an herb growing in Europe, and yields an oil
which is used in the preparation of Chartreuse and similar liquors.
The oil contains methyl chavicol, linalool, cineol, camphor, pinene,
and terpin hydrate.

Melissa officinalis (Sweet balm) is a perennial herb indigenous
to Europe and Asia and also cultivated. The leaves are ovate,
dentate, and the flowers are bilabiate, the calyx being bell-shaped
and 13-nerved. The taste is bitter, this being due to a bitter
principle. The fresh leaves are quite aromatic and produce from
o.i to 0.25 per cent, of a volatile oil containing a stearoptene.

Several species of Monarda known as HORSEMINT or wild

68o

A TEXT-BOOK OF BOTANY.

FIG. 373. Cat Mint or Catnip (Nepeta Cataria), a hardy perennial herb with heart-
shaped, oblong, deeply crenate, velvety, whitish green leaves, bearing in the axils dense
whorls of light purplish flowers. It is a common weed and derives its common name from
the fact that cats are fond of it, eating it and rubbing themselves upon it. — Bureau of Plant
Industry, U. S. Department of Agriculture.

bergamot are used in medicine. The oil was at one time official.
The oil of Monarda punctata, a perennial herb found growing

CLASSIFICATION OF ANGIOSPERMS.

681

from New York to Texas, contains thymol, thymoquinone, hydro-
thymoquinone, carvacrol, cymene, and limonene.

Nepeta Cataria (catnip) is a perennial herb naturalized in
the United States from Europe (Fig. 373). It contains a bitter

FlG. 374. (b) A mass of Ground Ivy (Nepeta hederacea) growing on an embankment,
with (a) Spring Beauty (Claytonia virginica).

principle, tannin, and an oxygenated volatile oil. Nepeta hede-
racea or GROUND IVY is a creeping perennial herb with blue bilabi-
ate flowers and reniform leaves (Fig. 374). It contains a bitter
principle and volatile oil. Cunila origanoides, or American DIT-

682

A TEXT-BOOK OF BOTANY.

TANY, is a small perennial herb growing from New York to
Florida, and characterized by its pungent aromatic properties.

Leonurus Cardiaca or MOTHERWORT is a perennial herb nat-
uralized in the United States and Canada from Europe. The

FIG. 375. Flowering tops of Datura fastuosa flava, a variety of a plant growing in the
East Indies, the Malay Archipelago, and tropical Africa, containing much the same con-
stituents as Datura Stramonium. — After Newcomb.

leaves are 3-lobed; the calyx is 5-nerved and with 5 prickly
teeth ; the corolla varies from white to pink or purple. The plant
contains a volatile oil of rather an unpleasant odor ; a bitter prin-
ciple; two resins and several organic acids, namely, malic, citric
and tartaric.

CLASSIFICATION OF ANGIOSPERMS.

683

/. SOLANACE^: OR POTATO FAMILY.— The family
includes herbs, shrubs, trees, and vines, which are most abundant
in tropical regions. The leaves are alternate and vary from entire

•

FIG. 376. Atropa Belladonna showing the alternate, petiolate, ovate, entire leaves,
in the axils of which are the solitray fruits or flowers with large, leafy bracts.

to dissected. The flowers are mostly regular, except in hyos-
cyamus. The stamens are adnate to the corolla tube, the anthers
connivent, and the pollen-sacs apically or longitudinally dehiscent.
The fruit is a berry or capsule in which the sepals mostly persist

.684 A TEXT-BOOK OF BOTANY.

and sometimes become enlarged or inflated. The seeds have a
large reserve layer, and the embryo is frequently curved.

Datura Stramonium (Jimson weed, thorn apple) is a large,
annual, branching herb, found in waste places in the United States
and parts of Canada, being naturalized from Asia. The leaves
and flowering tops are official. The large, spiny capsule is shown
in Fig. 236, B. D. fastuosa (Fig. 375) has similar medicinal
properties.

Atropa Belladonna (Deadly nightshade) is a perennial herb
producing a large, fleshy root, which is used in medicine (Fig.
376), as are also the leaves and flowering tops.

Scopolia carniolica is a perennial herb with nearly entire or
somewhat irregularly toothed leaves. The flowers are campan-
ulate and dark purple. The fruit is a globular, transversely dehis-
cent capsule (pyxidium).

Hyoscyamus niger or henbane is a biennial herb (Fig. 377) ,
the leaves and flowering tops of which are official.

Pichi is the dried leafy twigs of Fabiana imbricata, a shrub
with small, scale-like leaves, indigenous to Chile. It contains a
volatile oil; o.i per cent, of a bitter alkaloid ; a glucoside resem-
bling aesculin ; and a bitter resin.

Solatium Dulcamara (Bitter sweet) is a perennial, climbing
herbaceous plant, indigenous to Europe and Asia and naturalized
in the Northern United States. The branches which have begun
to develop periderm are collected, and were formerly official as
DULCAMARA. They are cut into pieces 10 to 20 mm. long which
are greenish-brown, hollow, with a sweetish, bitter taste and
contain a glucoside, dulcamarin, and the gluco-alkaloid solanine
(Fig. 378).

Solanum carolinense (Horse nettle) is a perennial herb having
numerous yellow prickles on the branches and leaves. The leaves
are oblong or ovate, irregularly lobed (Fig. 379). The flowers
are white or light blue and occur in lateral cymes. The fruit is
an orange-yellow, glabrous berry. The plant is common in waste
places in Canada and the United States east of the Mississippi.
The root and berries are used in medicine. The root is simple
and quite long, 5 to 10 mm. in diameter, yellowish-brown, the
bark readily separating from the wood. It has a narcotic odor

CLASSIFICATION OF ANGIOSPERMS.

685

377.

Flowering branch of Hyoscyamus niger annuum, showing sessile, acutely lobed
leaves and two of the funnel-form flowers. — After Newcomb.

and a sweetish, bitter, somewhat acrid taste. Both the root and
terries contain the gluco-alkaloid solanine, which varies from
0.15 (in the root) to 0.8 per cent, (in the berries).

686

A TEXT-BOOK OF BOTANY.

FIG. 378. Bittersweet (Solanum Dulcamara), a perennial, climbing or twining shrub,
with several types of leaves, varying from ovate heart-shaped. The flowers are blue or
purplish and hang in loose cymose clusters. The fruit is an ovoid, reddish berry and very
poisonous. It is sometimes eaten by children, producing fatal effects. — After Brown.

CLASSIFICATION OF ANGIOSPERMS.

687

Capsicum fastigiatum (Cayenne pepper) is a perennial, smooth,
herbaceous, or somewhat shrubby plant, with ovate, acuminate,
petiolate, entire leaves ; the flowers are greenish-white, and solitary

K

FIG. 379. Horse nettle (Solatium ca,rolinpnseV A, portion of shoot showing flowers
and fruits and spines on leaves and stem; B, longitudinal section of spine (s) and portion
of stem showing glandular (g) and non-glandular (h) hairs, and cells containing small
sphenoidal crystals (ca) ; C, thick-walled, strongly lignified cells of spine; D, portion of
fibrovascular bundle showing small sphenoidal crystals (ca) of calcium oxalate in the cells
accompanying the sieve; E, stellate, non-glandular hair; F, stbma of stem; G, diagram cf
cross section of flower showing sepals (s), petals (p), stamens (a), ovary (c); H, longitudinal
section of flower; I, stamen showing terminal pores; J, cross section of 2-locular berry;
K, pollen grains, 30 M in diameter.

in the axils of the leaves. The fruit is official and is known in
commerce as African or Cayenne pepper. This plant and a num-
ber of other species of Capsicum are indigenous to tropical

688 A TEXT-BOOK OF BOTANY.

America, where they are extensively cultivated, as also in Africa
and India.

Nicotiana Tabacum (Virginia Tobacco plant) is a tall annual
herb indigenous to tropical America and widely cultivated. The
stem is simple, giving rise to large, pubescent, ovate, entire, decur-
rent leaves, the veins of which are prominent and more or less
hairy. The flowers are long, tubular, pink or reddish, and occur in
terminal spreading cymes. The various forms of tobacco are
made from the leaves, which are hung in barns, whereby they
undergo a slow drying or process of curing. Other species of
Nicotiana are also cultivated, as N. persica, which yields Persian
tobacco ; and N. rustica, the source of Turkey tobacco. Tobacco
leaves contain from 0.6 to 9 per cent, of the alkaloid nicotine ; an
aromatic principle nicotianin or tobacco camphor, to. which the
characteristic flavor is due and which is formed during the curing
of the leaves. The dried leaves yield from 14 to 15 per cent, of
ash, consisting in large part of potassium nitrate.

Solanuvn tuberosum (Potato plant) is indigenous to the Andes
region of South America and is extensively cultivated on account
of the edible tubers. The tubers (potatoes) contain about 75 per
cent, of water, 20 per cent, of starch, and nearly 2 per cent, of
proteins in the form of large protein crystalloids. The fruits and
young shoots contain the gluco-alkaloid solanine and the alkaloid
solanidine. The tubers contain a small amount of solanine, which
is increased when they are attacked by certain fungi or exposed
to light. (Consult pp. 142, 148, 194, and 198.)

Besides the potato plant, several other plants belonging to the
Solanaceae yield vegetables, as the Tomato plant (Solanuin Lyco-
persicum) and the Egg plant (Solanum Melongena). Various
cultivated species of Capsicum annuum furnish the common red
peppers of the market.

g. SCROPHULARIACE^ OR FIGWORT FAMILY.—
The plants are herbs, shrubs or trees with opposite or alternate
leaves and perfect, mostly complete and irregular flowers. The
corolla and stamens show some resemblance to those of the Labi-
atse in that the corolla is frequently more or less 2-lipped and the
stamens are didynamous. The fruit is a dehiscent capsule and

CLASSIFICATION OF ANGIOSPERMS. 689

the seeds have a reserve layer and a straight or slightly curved
embryo. ,

FIG. 380. Culver's-root (Leptandra virginica) showing the verticillate leaves and the long
spike-like terminal racemes.

Leptandra virginica (Veronica virginica), or Culver's root, is
a perennial herb with leaves in whorls of 3 to 9, those on the upper
part of the stem being opposite. They are lanceolate, serrate,

44

690

A TEXT-BOOK OF BOTANY.

and pinnately veined ; the flowers are white or bluish, tubular, and
in dense racemes. The rhizome and roots are official (Fig. 380).

PIG. 381. Foxglove (Digitalis purpurea): The terminal i-sided raceme with slightly
irregular, declined, tubular flowers, and a leaf of the first year's plant with long, winged
or laminate petiole.

Digitalis purpurea (Foxglove) is a tall, biennial, pubescent
herb, producing the first year a large number of basal leaves
(Fig. 381), and the second, a long raceme of drooping, tubular,

CLASSIFICATION OF ANGIOSPERMS. 691

slightly irregular, purplish flowers ; the inner surface of the corolla
is spotted, the stamens are didynamous, and the upper calyx
segment is narrower than the others. The leaves are official in all
the pharmacopoeias.

The Scrophulariacese are well represented in the United States,
and a number of the plants have medicinal properties. The com-
mon MULLEIN (Verbascum Thapsus) contains a volatile oil,
two resins, and a bitter principle. The flowers of mullein contain
the same principles and in addition a yellow coloring principle.
Other species of Verbascum are used in medicine in different
parts of the world.

BUTTER-AND-EGGS (Linaria vulgaris) contains a crystalline
principle, linariin, antirrhinic acid, a volatile oil, resin, and tannin.
Several species of Scrophularia, as S. nodosa of Europe and S.
marilandica of the Eastern United States, contain a pungent
resin and a trace of an alkaloid. TURTLE-HEAD (Chelone glabra]
(Fig. 382) contains a bitter principle and gallic acid. The plant of
HYSSOP (Gratiola officinalis) of Europe contains gratiolin, a bitter
glucoside, and gratiosolin. The leaves of Curanga amara of the
East Indies contain a glucoside, curanjiin, which resembles digi-
talin in its action.

h. BIGNONIACE;E OR TRUMPET-CREEPER FAM-
ILY.— The plants are shrubs, trees or woody vines, and are repre-
sented in the United States by the catalpa tree (Catalpa bigno-
nioides) and the trumpet creeper (Tecoma radicans). The bark,
pods, and seeds of CATALPA have been used in medicine and con-
tain a bitter principle, catalpin, a glucoside, and several crystalline
principles. The TRUMPET CREEPER contains narcotic poisonous
principles. The leaflets of CAROBA (Jacaranda Copaia) and other
species of Jacaranda contain the alkaloid carobine, an aromatic
resin, carobone, and a principle having the odor of coumarin.

i. PEDALIACE^:.— The plants are herbs indigenous to the
Tropics of the Old World, some of which are now cultivated in
the Tropics of both hemispheres. Benne oil (oil of sesame) is
obtained from the seeds of Sesamum indicum by expression. It
consists chiefly of a glycerite of oleic acid, a glycerite of linoleic
acid, and myristin, palmitin, and stearin. It is a bland, non-drying
oil and is used like olive oil.

692

A TEXT-BOOK OF BOTANY.

PIG. 382. Turtle-head (Chelone glabra), a perennial herb with lanceolate, serrate,
opposite leaves and short, terminal spikes of whitish or purplish flowers. The corolla is
bilabiate, the mouth slightly open, the upper lip broad and arched, suggesting the head of
a turtle or snake, hence the origin of the common name. — Bureau of Plant Industry, U. S.
Department of Agriculture.

CLASSIFICATION OF ANGIOSPERMS. 693

FIG. 383. Purple Gerardia (Gerardia Purpurea, Fam. Scrophulariaceae) , a branching herb
with linear leaves; and large, bright purplish-pink, bilabiate flowers. — After Brown.

694

A TEXT-BOOK OF BOTANY.

/. ACANTHACE^; OR ACANTHUS FAMILY.— The
plants are mostly tropical perennial herbs, or shrubs with opposite

TlG. 384. Common Plantain (Plantago major). A very familiar weed found along
waysides and in poorly kept lawns. The leaves are clustered, lying near the ground, broadly
elliptical and with prominent parallel veins. The flowers occur in long, dense spikes which
give rise to small, capsular fruits, being sometimes employed as a green bird food. — After
Brown.

leaves ; in the mesophyll or epidermal cells and parenchyma of the
axis occur cystoliths. Several genera are represented in the
United States, one of which, Ruellia (Ruellia ciliosa), is the source

CLASSIFICATION OF ANGIOSPERMS.

695

PIG. 385. Squaw-root, also known as Cancer-root (Conopholis americana), one of the
OrobanchacecE or root parasites. It is shown here growing on the roots of another plant.
The flowering plants are from i to 2 dm. high, and consist of a cone-like stalk with fleshy
scales surmounted by a spike of more or less yellowish flowers. — After Troth.

696 A TEXT-BOOK OF BOTANY.

of the spurious spigelia which has been on the market for some
years past.

Ruellia ciliosa is a perennial herb which is distinguished from
the other species of the genus Ruellia by the leaves, stems, and
calyx being distinctly pubescent. The leaves are ovate-lanceolate,
nearly sessile and entire; the flowers are blue, sessile, solitary, or
two or three in a cluster, in the axils of the leaves ; the stamens
are 4, and exserted. The fruit is an oblong, terete capsule con-
taining from 6 to 20 orbicular seeds. The plant is found from
New Jersey and Pennsylvania to Michigan and as far south as
Florida and Louisiana. Long cystoliths are found in some of the
epidermal cells of both surfaces of the leaf.

Quite a number of the plants of the Acanthacese are used in
the Tropics in medicine. One of these, Adhatoda Vasica of trop-
ical Asia, contains the alkaloid vasicine, and is said to have the
property of destroying algae which grow in the rice swamps.

k. PLANTAGINACE^: OR PLANTAIN FAMILY.— The
plants are annual or perennial herbs, represented by but few
genera, but numerous species. The principal genus is Plantago,
which includes 200 species that are widely distributed. Several
species of Plantago are used in medicine. The common plantain
(Plantago major) contains a glucoside, acubin; emulsin; and
invertin, and the short rhizome, considerable starch. The seed-
coat has an outer mucilaginous layer, and the mucilage of the
seeds of Plantago Psyllium, P. arenaria (both of Europe), and
P. Ispaghula (of the East Indies) is used as a sizing material.
The seeds of a number of the species of Plantago are used as
bird food, particularly for canaries.

/. OROBANCHACE^: OR BROOM-RAPE FAMILY.—
This very interesting family is made up of plants which are
parasitic upon the roots of other plants and are consequently
rather light in color, as they develop no chlorophyll. Squaw-root
or Cancer-root (Conopholis americana) has the flowers arranged
in the form of a spike looking like an elongated cone, especially
after the flowers have begun to turn brown (Fig. 385). Another
little plant, also more or less white or yellow in color, is Beech-
drops (Epifagus), which develops upon the roots of the beech.

CLASSIFICATION OF ANGIOSPERMS. 697

VI. ORDER RUBIALES.

The plants of this order are distinguished from all of the
preceding Sympetalae by having flowers which are distinctly epigy-
nous. The leaves are opposite or verticillate.

a. RUBIACE^ OR MADDER FAMILY.— The plants are
herbs, shrubs, or trees, and of the representatives found in the
United States the following may be mentioned: Bluets (Hous-

PIG. 386. Cinchona Ledgeriana: A, flowering branch; B, bud and open flower;
C, fruiting branch. — After Schumann.

tonia species), Partridge-berry (Mitchella re pens), and Bedstraw
(Galium species). In Mitchella and Houstonia the flowers are
dimorphic.

CINCHONA species. — The plants are mostly trees, or rarely
shrubs, with elliptical or lanceolate, entire, evergreen, petiolate,
opposite leaves (Fig. 386). The flowers are tubular, rose-colored
or yellowish-white, and occur in terminal racemes. The fruit is
a capsule, which dehisces into two valves from below upward,
the valves being held above by the persistent calyx. The seeds

698

A TEXT-BOOK OF BOTANY.

CLASSIFICATION OF ANGIOSPERMS.

699

are numerous and winged. There are from 30 to 40 species of
Cinchona found growing in the Andes of South America at an
elevation above 800 M. in a restricted area about 500 miles in
length extending from Venezuela to Bolivia. The plants are

FIG. 388. Ipecac plant \Cephaelis (Uragoga) Ipecacuanha]: A, flowering shoot; B,
flower hrlongitudinal section ; C, fruit; D, fruit in transverse section; E.seed; F, annulate
root. — After Schumann.

cultivated in Java, Ceylon, New Zealand, and Australia, as well
as in Jamaica (Fig. 387).

There are two species which furnish the Cinchona bark of
medicine: (i) Cinchona Ledgeriana (C. Calisaya Ledgeriana) ,
which has small, elliptical, coriaceous leaves, the under surface
o! which is reddish ; small, yellowish, inodorous flowers, and a

700 A TEXT-BOOK OF BOTANY.

short capsule; (2) C. succirubra, which has large, thin, broadly-
elliptical leaves, purplish-red calyx, rose-colored petals, and a
very long capsule. • While C. Ledgeriana yields barks containing
the highest amount of alkaloids, C. succirubra is most cultivated.

Uragoga (Cephaclis) Ipecacuanha. — The plants are perennial
herbs 10 to 20 cm. high, with a creeping, woody, hypogeous stem.
The roots are official in all of the pharmacopoeias (see Vol. II).
The leaves are elliptical, entire, short-petiolate, and with divided
stipules (Fig. 386). The flowers are white and form small ter-
minal heads. The fruit is a blue berry, with characteristic spiral
arrangement of the carpels.

Coffea arabica is a small evergreen tree or shrub with lanceo-
late, acuminate, entire, slightly coriaceous, dark green, short-
petiolate leaves, which are partly united with the short inter-
petiolar stipules at the base. The flowers are white, fragrant, and
• occur in axillary clusters. The fruit is a small, spherical or ellip-
soidal drupe with two locules, each containing one seed, or COFFEE
GRAIN. The coffee plant is indigenous to Abyssinia and other
parts of Eastern Africa, and is cultivated (Fig. 389) in tropical
countries, notably in Java, Sumatra, Ceylon, and Central and South
America, particularly Brazil, over 600,000 tons being produced
annually in the. latter country. The yield of one tree is between
i and 12 pounds. There are two methods of' freeing the seeds
from the parchment-like endocarp : In the one case the fruits
are allowed to dry and are then broken ; in the other case, which
is known as the wet method, the sarcocarp is removed by means
of a machine, and the two seeds with the parchment-like endocarp
are allowed to dry in such a manner as to undergo a fermentation,
and after drying the endocarp is removed. Coffee seeds contain
from i to 2 per cent, of CAFFEINE ; from 3 to 5 per cent, of tannin ;
about 15 per cent, of glucose and dextrin; 10 to 13 per cent, of a
fatty oil consisting chiefly of olein and palmitin ; 10 to 13 per
cent, of proteins ; and yield 4 to 7 per cent, of ash. The official
caffeine is derived in part from coffee seeds.

In the ROASTING of coffee there is a change in the physical
character of the seeds, as well as a change in some of the constit-
uents. The AROMA is supposed to be due to an oil known as
coffeol, which is said to be a methyl ether of saligenin.

CLASSIFICATION OF ANGIOSPERMS.

701

FIG. 389. Coffee tree growing in Costa Rica. An evergreen shrub, with elliptical
leaves resembling somewhat those of the laurel. The flowers are white, fragrant, and are
formed in clusters among the branches, being followed by the berry-like fruits, which when
ripe are about the size of and resemble the cranberry. Each fruit contains two elliptical
plano-convex seeds, which on being separated constitute the so-called coffee bean of com-
merce.— Reproduced by permission of The Philadelphia Commercial Museum.

702 A TEXT-BOOK OF BOTANY.

YOHIMBI (Yohimbihi) bark is obtained from Corynanthe Yo-
himbe, a tree growing in the Cameroon region of Africa. The
pieces of bark are 25 cm. or more in length, 5 to 8 mm. thick,
externally dark brown or grayish-brown, and somewhat bitter.
Numerous bast fibers are present, but no sclerotic cells. It yields
4 alkaloids (0.3 to 1.5 per cent.), the principal one being yohim-
bine (corymbine or corynine), which forms white prismatic

FIG. 390. Picking coffee in Brazil. The coffee shrub is cultivated in plantations, and
when the berries are ripe they are collected either by shaking the tree and allowing the
berries to fall upon a cloth or they are picked by hand directly from the branches, and
removed from the field by oxen teams. More than half of the coffee of the world is grown in
Brazil, the remainder being obtained in various parts of tropical America and East India. —
Reproduced by permission of The Philadelphia Commercial Museum.

needles, soluble in alcohol and almost insoluble in water, and on
treatment with nitric acid becomes first deep green and then
yellowish, changing to a cherry-red if followed with an alcoholic
solution of potassium hydroxide (distinction from cocaine).

A number of the Rubiaceae contain valuable coloring prin-
ciples, as the madder plant (Rubia tinctorum}, which is a peren-
nial herb occurring wild in Southern Europe and formerly culti-
vated in France and Germany on account of the coloring principle

CLASSIFICATION OF ANGIOSPERMS. 703

FIG. 391. Buttonbush (Cephalanthus occidentalis) , a small shrub growing in swamps
and along streams throughout the United States. The leaves are opposite or whorled in
threes. The flowers are white and densely aggregated in spherical peduncled heads; they
secrete large quantities of nectar, and are sought to such a degree by the bees that the
bush is often called "Honey balls."— After Troth.

in its roots. The root is known commercially as MADDER, and con-
tains when fresh a yellow coloring principle, which on the drying
of the root breaks up into several glucosides, one of which on
further decomposition yields ALIZARIN, the principle to which the

704 A TEXT-BOOK OF BOTANY.

red color of the dried root is due. At present alizarin is made
artificially from anthracene, a coal-tar derivative.

Morinda citrifolia, a shrub widely distributed in tropical coun-
tries, contains a red coloring principle in the flowers and a yellow
coloring principle in the roots, the latter being known as morindin
and resembling the color principle in madder.

The pulp of the fruit of Cape jasmine (Gardenia jasminoides)
contains a yellow coloring principle resembling crocin, found in
Crocus.

The stem and root barks of Button-bush (Cephalanthus occi-
dentalis), common in swampy regions in the United States, are
used in medicine (Fig. 391 ) . The barks contain a bitter glucoside,
cephalanthin, and a tasteless glucoside which is fluorescent in solu-
tion. Mitchella re pens contains a saponin-like body in the fruit
and a tannin and bitter principle in the leaves. Quite a number of
species of Galium (bedstraw) are used in medicine and for other
purposes. A principle resembling glycyrrhizin is found in wild
licorice (Galium circazans) , a perennial herb growing in dry
woods in the United States, and also in Galium lanceolatum, which
is found from Virginia northward to Ontario. The yellow bed-
straw (Galium veruni), naturalized from Europe, contains a milk-
curdling ferment.

b. CAPRIFOLIACE^: OR HONEYSUCKLE FAMILY.—
The plants are perennial herbs, shrubs, trees, or woody climbers
with opposite, simple or pinnately compound leaves. The flowers
are perfect, epigynous, regular, or bilabiate, and arranged in
corymbs. The fruit is a berry, drupe, or capsule. They are mostly
indigenous to the northern hemisphere.

Viburnum prunifolium (Black haw) is a shrub or small tree
25 cm. in diameter. The winter buds are acute and reddish-
pubescent ; the leaves are ovate, elliptical, obtuse or acute at the
apex, somewhat rounded at the base, finely serrulate, glabrous,
and short-petiolate (Fig. 392) ; the flowers are white and in
nearly sessile cymes ; the fruit is a small, oval, bluish-black,
glaucous, inferior drupe. The root-bark is official.

Viburnum Opulus (Wild guelder-rose or cranberry-tree) is
a shrub about half the height of V. prunifolium, with broadly
ovate, deeply 3-lobed and coarsely dentate pubescent leaves. The

CLASSIFICATION OF ANGIOSPERMS. 705

flowers are white and in compound cymes, the outer being sterile
and large and showy. The fruit is a reddish, globular, very
acid drupe, clinging to the branches all winter. The Snow-ball
or guelder-rose of the gardens is a sterile variety of this species.
Another variety (edule) is also cultivated on account of its edible
fruits, particularly in Canada and the Northern United States.

FIG. 392. Fruiting branch of Viburnum prumfolium.

A number of species of Viburnum are rather common in
various parts of the United States, as the Maple-leaved arrow-
wood (V . acerifolium) , which is a small shrub with deeply
3-lobed, coarsely dentate leaves and small, nearly black drupes ;
Arrow-wood (V . dentatum), with broadly ovate, coarsely den-
tate leaves and blue drupes, which become nearly black when
45

;o6 A TEXT-BOOK OF BOTANY.

ripe; Soft-leaved arrow-wood (V . molle), which somewhat re-
sembles V. dentatum, but has larger leaves that are crenate or
dentate and stellate-pubescent on the lower surface ; Larger withe-
rod (V. nudum), having nearly entire leaves and a pink drupe,
which becomes dark blue.

Sambucus canadensis (American elder) is a shrub growing
in moist places in the United States as far west as Arizona and
in Canada. The leaves are 5- to 7-foliate, the leaflets being ovate,
elliptical, acuminate, sharply serrate, and with a short stalk ; the
flowers are small, white, and in convex cymes. The fruit is a
deep purple or black berry-like drupe. The dried flowers are used
in medicine. They are about 5 mm. broad, with a 5-toothed,
turbinate calyx, and a 5-lobed, rotate corolla, to which the 5 sta-
mens are adnate. The odor is peculiar and the taste is muci-
laginous and somewhat aromatic and bitter.

The active principles have not been determined, but are prob-
ably similar to those of S. nigra. The inner bark is also used in
medicine and contains a volatile oil, a crystallizable resin, and
valerianic acid. It does not appear to contain either tannin or
starch. The roots of elder contain a volatile principle somewhat
resembling coniine. The pith consists chiefly of cellulose, is deli-
cate in texture and has a variety of uses (Fig. 132).

The Black elder (Sambucus nigra), which is a shrub com-
mon in Europe, is characterized by narrower leaflets, a 3-locular
ovary, and black berries. The flowers are official in some of the
European pharmacopoeias. They contain about 0.4 per cent, of
a greenish-yellow, semi-solid volatile oil, which when diluted has
the odor of the flowers. They also contain an acrid resin.

The Red-berried elder or mountain elder (S. pub ens) some-
what resembles the common elder, but the stems are woody, and
the younger branches have a reddish pith. The flowers are in
paniculate cymes, and the fruits are scarlet or red.

Other plants of the Caprifoliaceae are also used in medicine.
Horse gentian (Triosteum perfoliatum), a perennial herb with
connate-perfoliate leaves and small, orange-red, globular drupes,
growing in Canada and the United States as far west as Kansas,
furnishes the drug (rhizome) known as WILD IPECAC or Trios-
teum. The rhizome is yellowish-brown, somewhat branched,

CLASSIFICATION OF ANGIOSPERMS. 707

cylindrical, 10 to 20 cm. long, 10 to 15 mm. in diameter, with
numerous cup-shaped stem-scars, and coarse, spreading roots;
it is rather hard and tough, and has a bitter, nauseous taste.
Triosteum contains an emetic alkaloid, triosteine, and considerable
starch. The seeds of Triosteum perfoliatum are sometimes roasted
and employed like coffee, the plant being known as Wild coffee.
The roots and stems of the following plants are sometimes
employed: The Snowberry (Symphoricarpos racemosus), the
Bush honeysuckle (Diervilla Lonicera), and various species of
Lonicera, these being also known as honeysuckles.

VII. ORDER VALERIANALES OR AGGREGATE.

The plants are mostly herbs with an inferior ovary, which is
either unilocular with a single pendulous ovule, or tri-locular
with frequently but a single anatropous ovule.

a. VALERIANACE^E OR VALERIAN FAMILY.— The
plants are herbs with opposite, exstipulate leaves, small, perfect,
or polygamo-dioecious flowers, occurring in corymbs. The fruit
is dry, indehiscent, and achene-like. The calyx is persistent, be-
coming elongated and plumose, and resembling the pappus in the
Composite.

Valeriana officinalis (Garden or Wild valerian) is a tall, peren-
nial herb, more or less pubescent at the nodes. The leaves are
mostly basal, pinnately parted into seven or more segments, which
are lanceolate, entire, or dentate. The flowers are white or pink
and arranged in corymbed cymes. The calyx is much reduced,
consisting of 5 to 15 pinnately branched teeth (pappus) ; the
corolla is tubular, somewhat sac-like on one side, but not spurred
as in other members of this family; the stamens are 3 in number
and adnate to the corolla tube ; the stigma is 3-lobed. The fruit is
ovoid, glabrous, and with a conspicuous plumose pappus. The
rhizome and roots are official.

The young leaves of several species of Valerianella are used
as a salad and are cultivated like spinach, as the European corn-
salad (V . olitoria) , which is also cultivated to some extent in
the United States.

b. DIPSACACE;E OR TEASEL FAMILY.— The plants are

annual or perennial herbs, chiefly indigenous to the Old World.

;o8 A TEXT-BOOK OF BOTANY.

The flowers are arranged in heads on a common torus, resem-
bling in some cases those of the Compositae.

Some of the plants are used in medicine, as the roots, leaves,
flowers, and seeds of Fuller's teasel (Dipsacus fullonum), the
roots of Succisa pratensis of Europe, and several species of Scabi-
osa and Cephalaria. The seeds of Cephalaria syriaca when
admixed with cereals give a bread that is dark in color and bitter.
This family is, however, chiefly of interest on account of Fuller's
teasel, which is a cultivated form of Dipsacus jerox, indigenous
to Southwestern Asia, the plant being cultivated in Europe and
New York State. The elongated, globular heads, with their firm,
spiny, and hooked bracts, are used in the fulling of cloth.

VIII. ORDER CAMPANULAT^E.

This order differs from the two preceding by having the
anthers united into a tube (syngenesious). It includes three prin-
cipal families, which are distinguished by differences in the char-
acter of the androecium: (a) Cucurbitaceae, in which there are
three stamens, having not only the anthers united but the fila-
ments also (monadelphous) ; (b) Campanulacese, in which there
are five stamens, both the filaments and anthers being united into
a tube; (c) Compositse, in which there are five stamens, but the
anthers only are united, the filaments being separate (Fig. 82, A).

a. CUCURBITACE^: OR GOURD FAMILY.— The plants
are mostly annual, tendril-climbing or trailing herbs (Fig. 66),
mainly indigenous to tropical regions. The leaves are alternate,
being opposite the tendrils, petiolate, and entire, palmately lobed
or dissected. The flowers are epigynous ; the petals are borne on
the calyx tube and frequently are united (campanulate) ; the ovary
is i- to 3-locular and with few or many anatropous ovules. The
fruit is a pepo, which is indehiscent but may burst somewhat
irregularly.

Citrullus Colocynthis is a trailing herb with deeply lobed
leaves. The flowers are yellow, axillary, and monoecious, the
staminate being with short filaments and glandular pistillodes
(aborted pistils), and the pistillate having a 3-locular, globose
ovary and three short staminodes. The fruit is globular, 5 to 10

CLASSIFICATION OF ANGIOSPERMS. 709

cm. in diameter, smooth, greenish, and mottled. The fruit de-
prived of the epicarp is official.

Cucurbita Pepo (pumpkin-vine) is an extensively trailing
hispid vine, with large, nearly entire, cordate leaves having long
petioles. The tendrils are branching. The flowers are large,
deep yellow, and monoecious ; the staminate ones being in groups
and the pistillate single. The ffuit is a large, yellowish berry,
sometimes weighing from 10 to 72 K. The seeds are numerous
and are official as Pepo.

Ecballium Elaterium (Squirting cucumber) is a bristly-hairy,
trailing perennial herb with thick, rough-hairy, cordate, some-
what undulate leaves. The flowers are yellow, monoecious. The
fruit is ellipsoidal, about 4 cm. long, rough-hairy or prickly, pend-
ulous, and at maturity separates from the stalk, when the seeds
are discharged upward through a basal pore. The plant is indig-
enous to the European countries bordering the Mediterranean,
the Caucasus region, Northern Africa and the Azores. The juice
of the fruit yields the drug ELATERIUM, which is official in the
British Pharmacopoeia. Elaterium yields 30 per cent, of the
ELATERIN of the Pharmacopoeias. From the latter by fractional
crystallization from 60 to 80 per cent, of a-elaterin, a laevo-rota-
tory crystalline substance is separated, which is completely devoid
of purgative action ; and varying amounts of /?-elaterin, a dextro-
rotatory crystalline compound which possesses a very high degree
of physiological activity (Power and Moore, Ph. Jour., 29, Oct.
23, 1909, p. 501 ; and Proc. Chem. Soc., No. 362, 1909, p. 1985).

Bryonia or BRYONY is the dried root of Bryonia alba (White
bryony), a climbing herb indigenous to Southern Sweden, East-
ern and Central Europe, including Southern Russia, and Northern
Persia (Fig. 181). The root contains two bitter glucosides,
bryonin and bryonidin ; two resinous principles and considerable
starch. Bryonia dioica (Red bryony) also has medicinal proper-
ties and is a source of the drug. B. dioica has red berries, while
the fruit of B. alba is black. The latter plant is sometimes known
as Black bryony, but this plant should not be confounded with
Tamus communis (Fam. Dioscoreaceae), of Southern Europe,
the rhizome of which is known commercially as Black bryony.

The fruits and seeds of various members of the Cucurbitacese

710 A TEXT-BOOK OF BOTANY.

contain powerful drastic and anthelmintic principles. A number
/ of the plants, however, are cultivated on account of the fruits,
which are used as food, as the pumpkin already mentioned, the
WATER MELON ( Citrullus vulgaris) , indigenous to Southern Africa
and cultivated in Egypt and the Orient since very early times ;
CANTALOUPE or musk-melon, derived from cultivated varieties of
Cucumis Melo, indigenous to tropical Africa and Asia, also culti-
vated since early times. The common CUCUMBER is obtained from
Cucumis sativus, which is probably indigenous to the East Indies.
These fruits contain from 90 to 95 per cent, of water, and the
water melon contains 3.75 per cent, of dextrose, 5.34 per cent,
of saccharose, and yields 0.9 per cent, of ash.

Luffa cylindrica is an annual plant indigenous to the Tropics
of the Old World. It is cultivated to some extent in America,
but especially in the Mediterranean region. The fruit is more or
less cylindrical and 20 cm. or more long. The pulp is edible and
the fibrovascular tissue forms a tough network, which, when the
seeds, epicarp, and pulpy matter are removed, constitutes the

LUFFA-SPONGE.

The fruits of Luffa operculata and L. echinata, both found in
Brazil, contain a bitter principle resembling colocynthin.

b. CAMPANULACE^E OR BELL-FLOWER FAMILY.—
The plants are mostly annual or perennial herbs, but are some-
times shrubby, with an acrid juice containing powerful alkaloids.
The rhizomes and roots of about twelve of the genera contain
inulin. The leaves are alternate ; the corolla is regular, cam-
panulate and rotate, or irregular, as in Lobelia. The fruit is a
capsule or berry containing numerous small seeds.

Lobelia infiata (Indian or Wild tobacco) is an annual, pubes-
cent, branching herb (Fig. 224), the dried leaves and. tops of
which are official (see Vol. II): About 15 different species of
Lobelia are used in medicine. The most important of those grow-
ing in the United States is the Cardinal flower or Red lobelia
{Lobelia cardinalis), a plant found in moist soil from Canada to
Texas, and characterized by its long, compound racemes of bright
scarlet or red flowers. The Blue cardinal flower or Blue lobelia
(L. syphilitica) is a plant of nearly the same habit and same gen-

CLASSIFICATION OF ANGIOSPERMS. 711

eral character, except that the flowers are of a bright dark blue
color or occasionally white.

c. FAMILY COMPOSITE.— This is a large group of plants,
which are annual, biennial, or perennial herbs, under-shrubs,
shrubs, trees and twiners or even climbers, a few being aquatic.
They contain inulin, a constituent peculiar to this group of plants.
The most distinguishing character is the inflorescence, which is
a head or capitulum (Fig. 228), consisting of one or two kinds
of flowers, arranged on a common torus, and subtended by a
number of bracts, forming an involucre. The flowers are epigy-
nous and the fruit is an achene, usually surmounted by the per-
sistent calyx, which consists of hairs, bristles, teeth or scales,
which are known collectively as the PAPPUS (Fig. 227).

The individual flowers are called florets (Figs. 241, 242), and
may be hermaphrodite or pistillate, monoecious, dioecious, or
neutral. Depending upon the shape of the corolla, two kinds of
flowers are recognized, one in which the corolla forms a tube,
which is 5-lobed or 5-cleft, known as TUBULAR FLOWERS (Figs.
227, 228, C) ; and one in which the petals are united into a short
tube, with an upper part that forms a large, strap-shaped, usually
5-toothed limb, known as LIGULATE FLOWERS (Figs. 227, 228, D).

In some of the plants of the Compositse the head consists of
ligulate flowers only, but in the larger number of plants the head
is composed of both tubular and ligulate flowers or tubular flowers
alone and accordingly two main groups or sub-families are dis-
tinguished. The sub-family in which all of the flowers are lig-
ulate is known as LIGULIFLOR^E, or CICHORIACE^:, by those who
give the group the rank of a family. This group includes plants
like dandelion, chicory, lettuce, and Hieracium. The group or
sub-family in which the flowers are all tubular or ligulate on the
margin only is known as the TUBULIFLOR^E. When the head
consists only of tubular flowers it is called DISCOID, but when
ligulate flowers are also present it is called RADIATE. When the
heads are radiate, as in the common daisy, the tubular flowers
are spoken of as DISK-FLOWERS, and the ligulate flowers as RAY-
FLOWERS. The disk-flowers are usually perfect, while the ray-
flowers are pistillate or neutral (without either stamens or pistils).
By some systematists the Tubuliflorae are divided into groups

A TEXT-BOOK OF BOTANY.

which have been given the rank of families. This division is
based especially on the characters of the stamens. In a small
group represented by the ragweed and known as the AMBROSI-
ACE^E, the anthers, while close together (connivent) , are not united,
and the corolla in the marginal or pistillate flowers is reduced to a
short tube or ring. In a large group, which includes probably
10,000 species and which is considered to be the COMPOSITE
proper, the stamens in the tubular flowers are syngenesious and
the marginal or ray-flowers are distinctly ligulate. This group
includes the daisy, sunflower, golden-rod, aster, thistle, and most
of the plants which yield official drugs.

It may also be added that the Composite is considered to be
the highest and youngest group of plants.

Taraxacum officinale (Dandelion) is a perennial, acaulescent
herb with milky latex; oblong-spatulate, pinnatifid or runcinate,
decurrent leaves, and with a i -headed scape, the stalk of which is
hollow. The flowers are ligulate, golden-yellow and numerous;
the involucre consists of two series of bracts, the inner one of
which closes over the head while the fruit is maturing, afterward
becoming reflexed. The fruit consists of a loose, globular head
of achenes, each one of which is oblong-ovate and with a slender
beak at the apex which is prolonged into a stalk bearing a radiate
tuft of silky hairs, which constitute the pappus. The root is fusi-
form and usually bears at the crown a number of branches 2 to 5
cm. long, having a small pith and other characters of a rhizome.
The root is official.

Lactuca virosa (Poison lettuce) is a biennial prickly herb,
with milky latex and oblong-obovate, spinose-toothed, runcinate
basal leaves and with alternate, somewhat sessile or auriculate,
scattered stem leaves, the apex and margin being spinose. The
flowers are pale yellow and occur in heads forming terminal pani-
cles. The involucre is cylindrical and consists of several series
of bracts. The flowers are all ligulate and the anthers are sagit-
tate at the base. The achenes are flattish-oblong, and the pappus,
which is raised on a stalk, is soft-capillary, as in Taraxacum.
The prepared milk-juice is official as Lactucarium.

Eupatorium perfoliatum (Boneset or Common thorough wort).
— The leaves and flowers are used in medicine.

CLASSIFICATION OF ANGIOSPERMS. 713

Eupatorium sebandianum, which is added to Mate as a sweet-
ening agent, contains two sweet glucosides ; eupatorin and reban-
din ; a bitter principle, and a resin.

GRINDELIA species. — The plants are perennial, greenish-yellow,
resinous herbs, sometimes being under-shrubs, with alternate>
sessile or clasping, oblong to lanceolate, spinulose-dentate leaves,
and large, terminal, yellowish heads, consisting of both ligulate
and tubular flowers. The leaves and flowering tops of Grindelia
cainporum, G. cuneifolia and G. squarrosa are official.

Erigeron canadensis or Leptilon caiiadense (Canada fleabane)
is an annual or biennial, hispid-pubescent herb found growing
in fields and waste places in nearly all parts of the world. The
stems are simple, with numerous crowded leaves and numerous
flowers occurring in terminal panicles. The plants are sometimes
branched and i to. 3 M. high. The leaves are linear, nearly entire,
of a pale green color, the lower and basal ones being spatulate,
petiolate and dentate or incised. The flowers are white and the
heads are composed of both ligulate and tubular florets, the former
being pistillate and not longer than the diameter of the disk. The
pappus consists of numerous capillary bristles and the involucre,
which is campanulate, consists of five or six series of narrow,
erect bracts. The fresh flowering herb contains 0.3 to 0.4 per cent,
of a volatile oil which is official, tannin, and a small amount of
gallic acid. The oil is obtained by distillation and consists chiefly
of d-limonene.

The genus Erigeron includes a number of species which have
medicinal properties. E. annuus (Sweet scabious or Daisy flea-
bane) is a low, branching, annual herb, characterized by its linear-
lanceolate or ovate-lanceolate leaves and its conspicuous flowers,
which resemble those of the common daisy, the ray-flowers often
being tinged with purple (Fig. 393). It contains a volatile, oil
resembling that of Canada fleabane, and tannin. The Philadel-
phia fleabane (Erigeron philadelphicus) is a perennial herb pro-
ducing stolons, and has clasping or cordate leaves, the basal being
spatulate, and is further distinguished by its light purplish-red
ray-flowers.

Anthemis nobilis (Roman chamomile) is an annual or peren-

714 A TEXT-BOOK OF BOTANY.

nial, procumbent, branched herb, with numerous 2- to 3-pinnately
divided leaves, the ultimate segments being narrow-linear. The
flowers occur in terminal heads with long peduncles, a conical
torus and few white pistillate ray-flowers. The flowers of culti-

FIG. 393. Daisy-fleabane (Erigeron annuus).

vated plants are official (see Vol. II), the heads consisting mostly
of ligulate flowers, forming so-called " double flowers," as in the
cultivated chrysanthemums.

Anacyclus Pyrethrwn (Pellitory) is a perennial herb resem-
bling Anthemis nobilis in its general characters. The ray-flowers,

CLASSIFICATION OF ANGIOSPERMS.

715

however, are white or purplish, and the pappus consists of a ring
or scale. The root is official.

Matricaria Chamomilla (German chamomile) is an annual,
diffusely branched herb, with pinnately divided leaves, consisting
of few, linear segments. The flowers are official (Figs. 228,
394).

FIG. 394. A single plant of Matricaria Chamomilla, showing nnely divided leaves and
numerous composite flowers. — After Newcomb.

Arnica montana is a perennial herb with small rhizome;
nearly simple stem ; opposite, somewhat connate, entire, spatulate,
hairy leaves, and yellow flowers in large heads with long peduncles.
The flowers are official.

Arctium Lappa (Burdock) is a coarse, branched, biennial or

7i6

A TEXT-BOOK OF BOTANY.

FIG. 395. Chicory or Succory (Cichorium Intybus), a branching perennial herb with
oblong or lanceolate, more or less clasping leaves and axillary clusters of violet-blue flowers.
The plant is cultivated as a pot herb and salad, and the young roots are used like carrots.
The plant is more widely grown for its roots, which are used in the preparation of a substi-
tute of coffee. — After Brown.

CLASSIFICATION OF ANGIOSPERMS.

717

perennial herb, with alternate, broadly ovate, repand, entire, tomen-
tose, mostly cordate leaves, the basal ones being from 30 to 45 cm.
long. The flowers are purplish-red or white, tubular and form
rather large corymbose heads ; the involucre consists of numerous
lanceolate, rigid, nearly glabrous bracts, which are tipped with

PIG. 396. Burdock (Arctium Lap pa), a biennial herb with large, mostly cordate
leaves crowded at the base of the stems, and bearing small clusters of purplish flowers in
the shorter branches above. It is a common roadside weed, and well known because of
the burr-like fruits, consisting of the hooked tips of the bracts of the involucre. — After
Brown.

hooked, spreading bristles. The achenes are oblong and some-
what 3-angled, and the pappus consists of numerous short bristles
(Fig. 396). The root is used in medicine.

The common burdock (Arctium minus) resembles A. Lap pa,
but is a smaller plant and is more common in the United States.
The heads are smaller and the inner bracts are shorter than the

718 A TEXT-BOOK OF BOTANY.

tubular flowers, the bristles of this series being erect and with
the outer spreading.

Calendula officinalis (Marigold) is an annual herb with alter-
nate, spatulate, oblanceolate, entire or serrate leaves. The flowers
are yellow and form solitary heads, consisting of both ray and
tubular florets. In the cultivated varieties most of the tubular
florets are changed to ligulate, the latter being official (Fig. 227).

While the Compositae include a large number of genera and
species, the plants do not yield many important drugs, although a
number are used in medicine and for other purposes.

The so-called INSECT FLOWERS (Pyrethri F lores) are the
partly expanded flower-heads of several species of Chrysanthe-
mum, and are used in the preparation of a powder which is a
powerful insecticide. T.he plants are perennial herbs resembling
in their habits the common white daisy (C. Leucanthemum) . The
DALMATIAN Insect Flowers are obtained from C. cineraria: folium,
growing in Dalmatia, and cultivated in Northern Africa, Cali-
fornia and New York. The heads as they occur in the market
are about 12 mm. broad, light yellowish-brown and have a slightly
rounded or conical torus, which is about 12 mm. in diameter and
consists of 2 or 3 series of lanceolate involucral scales. The ray-
florets are pistillate, the corolla varying in length from i to 2 cm.
and having numerous delicate veins and 3 short, obtuse or rounded
teeth. The tubular flowers are perfect and about 6 mm. long. The
ovary is 5-ribbed and the pappus forms a short, toothed crown.
The odor is distinct and the taste bitter.

PERSIAN Insect Flowers are derived from C. rosemn and C.
Marschallii, growing in the Caucasus region, Armenia and North-
ern Persia. The heads are about the size of those of C, cinerarice-
folium; the torus is dark brown; the involucral scales and ray-
florets are purplish-red ; the ovary is lo-ribbed.

Insect flowers contain from a trace to 0.5 per cent, of a vola-
tile oil, the Persian flowers containing the larger proportion, and
the amount decreasing with the maturing of the flowers. They
also contain two resins, varying from 4 to 7 per cent., the larger
amount being found in the Dalmatian flowers ; a small quantity
of a glucO'side and a volatile acid.

The principle toxic to insects is PYRETHRON, an amber-yellow,

CLASSIFICATION OF ANGIOSPERMS. 719

syrupy substance which is the ester of certain unidentified acids,
and on saponification yields the alcohol pyrethrol which crystal-
lizes in fine needles. The acids combined in the ester pyrethron
do not give crystalline salts.

WORMWOOD or Absinthium consists of the dried leaves and
flowering tops of Artemisia Absinthium, a perennial, somewhat
woody, branching herb, indigenous to Europe and Northern
Africa, cultivated in New York, Michigan, Nebraska and Wis-
consin and naturalized in the United States from plants that have
escaped from cultivation. The leaves are grayish-green, gland-
ular-hairy, I- to 3-pinnately divided, the segments being obovate,
entire, or lobed ; the flowers are yellowish-green, the heads being
about 4 mm. broad and occurring in raceme-like panicles ; the
torus is hemispherical and the involucre consists of several series
of linear bracts, the inner being scale-like ; the florets are all
tubular, the outer ones sometimes being neutral. The herb is
aromatic and very bitter.

The fresh drug contains about 0.5 per cent, of a VOLATILE OIL
which is of a dark green or blue color, has a bitter, persistent taste
but not the pleasant odor of the plant, and consists of d-thujone
(absinthol), thujyl alcohol free and combined with acetic, iso-
valerianic and palmitic acids, phellandrene and cadinene. The
other constituents oi the drug include a bitter glucosidal principle,
ABSINTHIIN, which forms white prisms and yields on hydrolysis
a volatile oil ; a resin ; starch ; tannin ; succinic acid, potassium
succinate, and about 7 per cent, of ash. The plant is used in the
preparation of the French liquor known as ABSINTHE.

Artemisia Cina yields the official Santonin.

Other species of Absinthium also yield volatile oils, as the
COMMON MUGWORT (Artemisia vulgaris), which yields from o.i
to 0.2 per cent, of an oil containing cineol ; Artemisia Barrelieri,
which contains an oil consisting almost entirely of thujone, and
said to be used in the preparation of Algerian absinthe.

SAFFLOWER consists of the dried florets of Carthamus tinc-
torius, an annual herb which is known only in cultivation. The
florets are tubular, yellowish-red, the corolla tube being about
2 cm. long and with 5 small, linear lobes ; the stamens are exserted.
The ovary with the long, slender style is usually not present in

720 A TEXT-BOOK OF BOTANY.

the drug (Fig. 227, C). Safflower contains a small percentage
of a yellow coloring principle (safflower-yellow), which is soluble
in v/ater, and 0.3 to 0.6 per cent, of a red coloring principle (car-
thamin or carthamic acid), which is insoluble in water but soluble
in alcohol, the solution having a purplish-red color. A volatile
oil is also present. Carthamin is used in conjunction with French
chalk in the preparation of a rouge.

TANSY is the dried leaves and tops of Chrysanthemum (Tana-
cetum vulgar e), a perennial, aromatic herb indigenous to Europe,
extensively cultivated and naturalized in the United States. The
leaves are large and pinnately divided, and the flowers, both tubu-
lar and ligulate, are yellow, the heads being in terminal corymbs.

The plant yields from o.i to 0.3 per cent, of a volatile oil,
consisting of thujone, borneol and camphor ; and 3 resins.

ELECAMPANE (Inula Helenium) is a large, perennial, densely
pubescent herb with alternate leaves and large, solitary terminal
heads, consisting of yellow tubular and ligulate florets (Fig. 227).
The plant is indigenous to Central Europe and Asia, and natural-
ized in North America from Canada to North Carolina. The
root is used in medicine and was formerly official as INULA.

The root of Polymnia Uvedalia, a plant closely related to
Inula, but indigenous to the United States east of the Mississippi,
contains a volatile oil, a glucoside, tannin, and a resinous sub-
stance consisting of two resins, one of which is pale yellow and
soft, the other dark brown and hard.

The following Composite, while not of very great importance,
are used in some localities:

YARROW (Achillea Mille folium) is a common weed naturalized
from Europe (Fig. 397), and contains about o.i per cent, of a dark
blue volatile oil with a strongly aromatic odor and a small amount
of a bitter alkaloid, achilleine. The roots of yarrow, on the other
hand, yield a volatile oil with a valerian-like odor. Achillea nobilis
of Europe contains an oil resembling that of yarrow, but it is of
finer quality and has a spice-like taste. Achillea moschata, an
alpine plant of Europe, yields three alkaloids and a volatile oil
containing cineol, and is used in Italy in the preparation of the
liquor, "Esprit d' Iva." Achillea tanacetifolia yields a blue volatile
oil having the odor of tansy.

CLASSIFICATION OF ANGIOSPERMS. 721

FIG. 397. Yarrow or Milfoil (Achillea Millefolium), a perennial herb, branching only
at the top and bearing deeply pinnatifid leaves, the segments being very narrow. The
flowers are small, white, occasionally crimson and arranged in large, terminal corymbs. —
Bureau of Plant Industry, U. S. Department of Agriculture.

The HIGH GOLDEN-ROD (Solidago canadensis) yields 0.63 per
cent, of a volatile oil, consisting chiefly of pinene, with some phel-
46

722

A TEXT-BOOK OF BOTANY.

landrene and dipentene, and containing about 9 per cent, of
borneol, 3 per cent, of bornyl acetate and some cadinene. The
True or ANISE-SCENTED GOLDEN-ROD (Solidago odora) yields
an aromatic volatile oil and a small amount of tannin.

FIG. 398. Method of gathering the pollen of Golden-rod (Solidago Shortii} for immuniz-
ing the hay-fever horses. The plant is gathered just about the time that the pollen-sacs
are ready to open, then taken to a sunny room — free from draft and air disturbances —
placed slanting in a basin filled with water, the blossoms drooping over the sides of the
vessel, with clean, smooth paper spread underneath them. The following morning the
pollen will be on the paper and can readily be gathered with a feather-top or a quill. —
After Schimmel & Co.

The rhizome of the large Button-snakeroot (Lacinaria scari-
osa), growing in the eastern and central portion of the United
States and Canada, contains o.i per cent, of volatile oil, about
5 per cent, of resin, and 2 per cent, of a caoutchouc-like substance.

CLASSIFICATION OF ANGIOSPERMS. 723

COLTSFOOT (Tussilago Farfara) is a plant indigenous to
Europe and naturalized in the Northern United States and Can-
ada. It is an acaulescent herb with a slender rhizome 30 to 40
cm. long ; nearly orbicular, somewhat lobed and tomentose leaves,
and large, solitary, yellow flowers appearing before the leaves.
The plant contains an acrid volatile oil, a bitter glucoside, resin
and tannin.

ECHINACEA is the root of Brauneria (Rudbeckia) pur pur ea,
a plant growing in rich soil from Virginia to Illinois and south-
ward, and of B. angustifolia, growing from the Northwest Terri-
tory to Texas (Fig. 399). The drug contains an alkaloid and
0.5 to i per cent, of an acrid resinous substance to which the
medical properties are due.

ROSIN WEED or COMPASS PLANT (Silphium laciniatum) ,
found growing from Ohio to South Dakota and south to Texas,
produces an oleo-resin which exudes either spontaneously or from
the punctures of insects, and contains about 19 per cent, of vola-
tile oil, and 37 per cent, of acid resin.

The THISTLE (Cnicus benedictus) contains a crystalline bitter
principle, cnicin, which is colored red with sulphuric acid.

The Mexican drug PIPITZAHOAC is the rhizome of Perezia
Wrightii, P. nana and P. adnata, plants found in Southwestern
Texas and Mexico*. It contains about 3.6 per cent, of a golden-
yellow crystalline principle, pipitzahoic acid, which appears to be
related to oxythymoquinone and is colored an intense purple with
alkalies and alkaline earths.

LION'S FOOT, the root of Prenanthes Serpentaria, P. alba and
other species of Nabalus growing in the United States, contains
bitter principles, resin and tannin. Mio Mio (Baccharis cordi-
folia), of South America, is poisonous to sheep and cattle and
contains an alkaloid, baccharine, and a bitter principle. SPINY
CLOTBUR (Xanthium spinosum) contains a bitter resin and possi-
bly a volatile alkaloid. The fruit of Xanthium spinosum, a
common weed naturalized from Europe, contains an amorphous,
non-glucosidal substance, xanthostrumarin, which forms precip-
itates with a number of the alkaloidal reagents. SNEEZE- WEED
(Helenium autumnale) contains a volatile oil, a bitter glucoside
and tannin. Helenium tenuifolium, of the Southern United States,

724

A TEXT-BOOK OF BOTANY.

FIG. 399. A flowering specimen of the Purple Cone-flower (Brauneria angustifolia) ,
showing the 3-nerved lanceolate leaves and 2 of the flower heads with the characteristic
long spreading rays. — After Newcomb.

is a narcotic poison. PARA CRESS (Spilanthes oleracea), of trop-
ical America, contains a soft pungent resin and a crystallizable
principle, spilanthin. The common white daisy (Chrysanthemum

CLASSIFICATION OF ANGIOSPERMS. 725

Leucanthemum) yields about 0.15 per cent, of a greenish volatile
oil with the odor of chamomile and mint.

CHICORY, the root of Cichorium Intybus, a perennial herb
with blue or purplish ligulate florets, indigenous to and cultivated in
Europe and naturalized in the United States (Fig. 395), is used
in medicine as well as in the preparation of a coffee substitute.
The root is spindle-shaped, somewhat resembling Taraxacum, but
is of a light brown color and the laticiferous vessels are arranged
in radial rows in the somewhat thinner bark. It contains a bitter
principle and a large amount of inulin. In the preparation of a
coffee substitute the root is cut into rather large, equal pieces and
roasted, after which it is ground to a yellowish-brown, coarse
powder. The grains are heavier than water, imparting to it a
yellowish-brown color. Under the microscope it is distinguished
by the branching latex-tubes and rather short, oblique tracheae
with rather large, simple pores.

The SUNFLOWER (Helianthus annuus) is an annual herb indig-
enous to tropical America and extensively cultivated. The plant
is grown on a large scale in Russia, Hungary, Italy and India for
its fruits, which yield a fixed oil resembling that of cotton seed.
The achenes (so-called seeds) are obovate, flattened, externally
black or with alternate white and black stripes, the pappus con-
sisting of two deciduous, chaffy scales. Sunflower seed-cake is
readily distinguished by a few of the fragments of the epicarp,
with the characteristic twin, unicellular, non-glandular hairs and
large, oblique, but rather short, sclerenchymatous fibers. Besides
40 per cent, of a fixed oil, the seeds contain a peculiar glucosidal
tannin, helianthic acid, which is colored deep green with ferric
chloride and yellow with alkalies. The root contains inulin ; the
shoot asparagin, and the fresh pith about 1.5 per cent, of potas-
sium nitrate. The pith has been used in the preparation of
MOXA, a combustible vegetable material which burns without fus-
ing and is used by the Portuguese to destroy any deep-seated
inflammation. The pith of various species of Artemisia, which
also contains considerable potassium nitrate, furnishes the Chinese
Moxa.

JERUSALEM ARTICHOKE (Helianthus tuber osus) is a large,
coarse, pubescent herb with yellow ray-florets, which is indigenous

726 A TEXT-BOOK OF BOTANY.

to the Middle United States and sometimes cultivated. The
tubers, which resemble artichokes, are more or less elongated or
pear-shaped, reddish-brown, somewhat annulate, and internally
white or reddish. They have been used as a substitute for pota-
toes and contain about 16 per cent, of the following carbohydrates :
Inulin, pseudo-inulin, inulenin, saccharose, helianthenin, and syn-
antherin. In early spring with the development of the tubers there
is formed a small quantity of dextrose and levulose.

The Globe artichoke of the gardens (Cynara Scolymus) is a
hardy perennial and is valued on account of the fleshy involucral
scales and torus, which are edible.

The POLLEN of a number of plants of the Composite, as rag-
weed (Ambrosia), golden-rod (Solidago), aster and chrysanthe-
mum, is said to be responsible for the autumnal cold, known as
HAY FEVER. A similar disease is produced in spring and early
summer by the pollen of certain grasses. It has been found that
the pollen grains of these plants contain a highly toxic substance,
belonging to the toxalbumins, which is the cause of the disease.
By inoculation of rabbits, goats and horses with this toxalbumin
a serum containing an antitoxin is obtained which neutralizes the
pollen toxin and protects those who are susceptible to hay fever
from its attacks. In practice the serum is prepared by injecting
the toxalbumin subcutaneously into horses, the serum being known
in commerce as POLLANTIN (Fig. 398).

The pollen of the following plants is toxic: aster, barley,
chrysanthemum, convallaria, corn-flower, golden-rod, grasses,
honeysuckle, oats, cenothera, ragweed, rice, rye, spinach, wheat,
and zea. The constituents of rye pollen are 86.4 per cent, of
organic matter, 10.2 of water, and 3.4 of ash. The organic matter
consists of 40. per cent, of toxic substances, 3 of fixed oil, 25 of
carbohydrates, and 18 of a non-albuminous substance. The num-
ber of pollen grains per gram varies in different plants : from
Indian corn being 7,000,000, of rye 20,000,000, of golden-rod
80,000,000, and of ragweed 90,000,000.

The flowers of the Japanese chrysanthemum " Riuno-kiku "
(Chrysanthemum sinense japonicum) yield 0.8 per cent, of a
volatile oil containing an optically inactive crystalline iso-camphor.

CHAPTER VI.
CULTIVATION OF MEDICINAL PLANTS.

WHEN the forests and woods were full of wild medicinal plants
that could be easily gathered, there was hardly an incentive
to consider the farming of them. Now that they are becoming
scarcer, the need is especially apparent. Our interest in the culti-
vation of medicinal plants, however, is not primarily because there
is a growing scarcity of the sources of supply, but in order that
drugs of uniform quality and increased value may be had. For-
tunately, there is a tendency on the part of some manufacturing
pharmacists to concentrate their efforts upon a few plants yielding
drugs and to study them in relation to their active principles
throughout different periods of the season. In addition to these
actual experiments, there are numerous inquiries made regarding
the possibilities of the successful farming of medicinal plants.
These inquiries come from various people who, for one reason
or other, would like to get into country life and have some definite
work to do. Many of them have never had any practical experi-
ence in growing plants other than taking care of a garden plot.
Nearly all know nothing of the commerce of drugs and have no
idea of the problems connected with the disposition and marketing
of them. Fortunately, some experiments have been conducted
and there is some general information as to how one should
proceed in the work. However, it must be said at the outset, no
one can grow medicinal plants without having some training and
special education for it ; and unless one is familiar with the prac-
tical conditions of trade, that is in regard to the markets and
prices paid for drugs, even though successful in raising a good
crop, one may not be able to dispose of it. It is very difficult to
lay down any one rule that can be invariably followed on this sub-
ject. In fact, very little work has been done to enable us to draw
other than very broad conclusions. The first thing to be consid-
ered is locality. Of course, tropical plants would not grow in
the temperate zone, nor mountainous plants at the seaside, although
even here there are exceptions that only experiments can show.

727

728 A TEXT-BOOK OF BOTANY.

Then again, there are plants which grow only in the rich woodland
soil, while others grow in barren soil in open places. Some plants
require special kinds of soil, as Atropa Belladonna and Cannabis
sativa, which do not seem to reach a high state of cultivation except
in a calcareous soil. On the other hand, the plants of the Ericaceae
are peculiar in that they require an acid soil (pp. 250, 656).

In beginning this work in a new locality it is very important
to make a rather careful survey of the plants growing wild, or
those which have become naturalized. It would be safe to say
that within certain limits, if there are a number of genera of any
family well represented that has some of the habits of the plant
with which one desires to experiment with, there is a probability
that it may be grown successfully. This can be ascertained to some
extent by the nature of the plants that are brought under cultiva-
tion. For instance, digitalis might be grown very successfully
in localities where it is cultivated and has become naturalized.
By a priori reasoning, in the cultivation of licorice, the ideal
location for growing the plant would be in the West and North-
west where the wild licorice, Glycyrrhiza lepidota, is indigenous.
In addition, it is necessary to study the best ways of propagating
the plant one wishes to grow. Sometimes this is by means of
seeds, as in belladonna and digitalis ; at other times it is by propa-
gation of rhizomes, as hydrastis and glycyrrhiza ; or again by
root-stocks or prostrate stems, as in the mints. Sometimes both
seeds and cuttings may be used, as in the case of hydrastis.

PLANTS GROWN FROM SEEDS. — A large number of plants can be
grown from seeds, and when they are grown in this manner, espe-
cially in a temperate climate, where the growing season is rather
short, it is necessary to begin the germination of the seed early
in the spring. This must be done in the house or under conditions
where there is some protection. They may be sown either in small
boxes or seed pans, in which the soil is quite sandy or made up
largely of broken granitic rock (Fig. 400), and which must be
clean and free from organic matter that is likely to mould. The
seeds should not be planted too deep, and the boxes or pans should
be covered with glass so as to condense or hold moisture. Of
course, where there is the necessary attention, so far as keeping
the earth moist is concerned, this can be dispensed with. The

CULTIVATION OF MEDICINAL PLANTS. 729

FlG. 400. Digitalis Seedlings in seed pans, ready to be transplanted into plant flats.
This is the first step in the propagation of Digitalis.— From the Experimental Farm of
Eli Lilly & Company, Indianapolis, Ind.

730

A TEXT-BOOK OF BOTANY.

time required in germination will vary considerably. Many seeds
will germinate well within two weeks ; usually probably four or
five weeks are necessary. Occasionally some seeds, as with roses,
may require a year or two. The present tendency is to shorten
the period of germination in several ways. The simplest, possibly,
is to place the seeds in water for 24 hours. If the seed-coat is
more or less lignified and non-porous, boiling water is poured upon
them, or some special treatment may be given, as the use of dilute

FIG. 401. Digitalis Seedlings in plant flat, three months after transplanting from
seed pans. These plants are now ready to be transferred to cold frames. — From the Ex-
perimental Farm of Eli Lilly & Company, Indianapolis, Ind.

or even concentrated mineral acids. For instance, in the culti-
vation of Paraguay tea or mate, for many years it was found that
the seeds would not germinate unless they had previously passed
through the alimentary tract of certain birds. Later it was found
that the same results could be obtained by placing the seeds in solu-
tions of hydrochloric acid. Miller reports that he has obtained
good results in the case of belladonna by first placing the seeds for
30 or 40 seconds in concentrated sulphuric acid. The germination
of seeds may also be hastened by certain mechanical means. These
are employed when the seed-coat is unusually thick and not easily

CULTIVATION OF MEDICINAL PLANTS. 731

penetrated by the moisture; or if the seeds are large, they may
be filed in one or two places; when they are small they may be
shaken with sharp, angular sand until the exterior is somewhat
roughened.

After the seedlings have put forth a few leaves they are then
set out in suitable boxes known as flats (Fig. 401) which contain
a soil having a fair amount of nutriment. The plants must be
watched at this point to see that there is no damping off and loss
by reason of attacks by soil micro-organisms.

FIG. 402. Cold frames for use in propagating such plants as Digitalis, Belladonna,
Henbane, etc. The young seedling plants are transferred from the greenhouse to these
cold frames in late spring for the purpose of hardening them before transplanting to the
open field. — From the Experimental Farm of Eli Lilly & Company, Indianapolis, Ind.

Should there be a damping off and loss of seedlings some
method should be employed to overcome it. Recently the De-
partment of Agriculture has utilized dilute sulphuric acid, which
Kraemer has shown is the active principle produced whenever
sulphur is used in the greenhouse, for the destruction of insect
pests, as well as the blights due to fungi and other micro-
organisms.

The plants are allowed to grow in the flats until they have
developed a good root system and have produced a shoot with
3 or 4 leaves. They are then transferred to cold frames (Fig.
402), where they remain until they are acclimatized or hardened

732

A TEXT-BOOK OF BOTANY.

sufficiently to be planted directly in the soil. This transferring
should be done not later than the early part of May. The structure
and use of the cold frame is perfectly familiar to the practical
gardener.

Sometimes the individual plants are removed from the flats
and placed directly in the soil of cold frames. .This may give
them a temporary setback, as the roots are more o-r less disturbed

FlG. 403. A general view of the testing and breeding of medicinal plants at the Experi-
mental Farm of Eli Lilly & Company, Indianapolis, Ind.

by the operation, but if the experiment in the cold frames is to be
continued considerable time will be saved.

If the plants are to be transplanted out of doors it is desirable
that this should be done as soon as possible after the last days
are over for the possibility of frost. The plants are arranged
in rows and set sufficiently far apart so the maximum crop per acre
can be obtained (Figs. 403-407), and also that weeds may be
pulled out and the ground worked over.

The above outline given may be used for the propagation of

CULTIVATION OF MEDICINAL PLANTS. 733

most plants by seedlings. Some plants are rather easily grown if
care is taken with their culture, as digitalis and belladonna. Other
plants, like hyoscyamus, are with some difficulty cultivated, and
very few persons, even seedsmen, are uniformly successful in
growing aconite. It should also be stated that there are a number
of plants yielding medicinal products which are grown from
seeds and require no more care than the usual garden plants.
Among these are calendula, Chrysanthemum roscum, echinacea,

FlG. 404. Harvesting a unit test plot of first-year Digitalis. — From the Experimental
Farm of Eli Lilly & Company, Indianapolis, Ind.

and a number of others grouped under sweet, pot, and medicinal
herbs.

PROPAGATION BY CUTTING. — This is a common method of
propagating plants, being extensively employed by florists. A
cutting is a severed portion of a stem having one or more nodes
or buds. They • are derived either from over-ground shoots,
as in carnation, rose, geranium, and coleus, or, where the plant
produces root-stocks or rhizomes, they are made from these rather
than from the over-ground shoots. Not all plants can be propa-
gated equally well from cuttings. Some plants are readily propa-

734

A TEXT-BOOK OF BOTANY.

gated in this way, as the willows, the twigs of which, when they
fall off or are broken off, frequently take root in the moist soil.
Other plants, like the oak, are very difficult to grow from cuttings.
In propagating plants from rhizomes the latter are cut into pieces,
each of which has one or two> buds, and these pieces are planted.
Among the medicinal plants which have been grown from cuttings
of rhizomes are licorice, peppermint, hydrastis, and ginger, but
it is likely that all plants which produce rhizomes can be readily

FIG. 405. Goldenseal (Hydrastis canadensis) farming in a natural woodland glade. —
From Wellcome Materia Medica Farm near Dartford, England.

propagated in this manner. Cuttings of over-ground stems are
made from the growing parts of branches, and it is necessary to
have them of such a length that at least one node may be placed
in the soil. These are at first planted in micaceous soil or river
sand, which should be kept well moistened. It is desirable that
the leaves be as few as possible, so as to reduce the transpiring
surface until the young roots have been formed, wrhich may take
several weeks or several months. Usually the lower leaves should
be cut off entirely, while the others may be partially trimmed. The

CULTIVATION OF MEDICINAL PLANTS. 735

cuttings should also be protected from strong light, as this tends
to increase transpiration, and also- guarded against a dry atmos-
phere, which may be accomplished by covering them with glass,
particularly during the day, when the weather is dry. Cuttings
of hard wood plants intended for outdoor culture should be made
in the fall. They should be 6 or 8 inches in length, kept covered
with sand in a suitable place during the winter, and planted in the
spring.

FIG. 406. Goldenseal (Hydrastis canadensis) farming under an artificially constructed
shade. — From Wellcome Matena Medica Farm near Dartford, England.

In the case of both ginseng and hydrastis, one-year-old plants
are often supplied by growers, and, though this is not always desir-
able, yet there are conditions where, for experimental purposes,
they may be used. It should be emphasized that it is not merely a
matter of getting rhizomes or young plants, but a very careful
study should be made of the conditions governing soil and light,
and which favor the maximum returns from the crop (Figs. 405-
407). Caution should be exercised in the use of manure for in-
creasing the yield of the crop as well as the plant constituents.

736

A TEXT-BOOK OF BOTANY.

CULTIVATION OF MEDICINAL PLANTS. 737

The method for producing new varieties is by hybridization,
or cross-pollination, of different related species or varieties (Fig.
403). The offspring is known as a HYBRID, and has a blending of
the qualities or characters of the two parent plants. This method
is mostly employed by florists who desire to produce some new
or striking flower, or by horticulturists who desire to establish
some new quality or transfer a desirable quality from a foreign
plant to one which is adapted to a given locality. The method
has not been largely employed in the cultivation of medicinal
plants, except in the case of cinchona, where it is claimed that the
barks richest in alkaloids are the direct result of hybridization
and selection. By transplanting and special methods of treat-
ment, as that of mossing, the alkaloidal percentage has been in-
creased from S per cent, to 10, whereas by hybridization the
amount of total alkaloids has reached as high as 16 per cent., about
three- fourths being quinine.

COLLECTING AND DRYING OF DRUGS. — The time of the COLLEC-
TION of vegetable drugs is of prime importance, and, while it
may not be possible to make extended generalizations, still, the fol-
lowing rules for the collection of various drugs may be given :

(1) Roots, rhizomes, and barks should be collected immedi-
ately before the vegetative processes begin in the spring, or
immediately after these processes cease, which is usually in the
fall.

(2) Leaves should be collected when photosynthetic processes
are most active, which is usually about the time of the develop-
ment of the flowers and before the maturing of fruit and seed.

(3) Flowers should be collected prior to or just about the
time of pollination.

(4) Fruits should be collected near the ripening period, i.e.,
full grown but unripe.

(5) Seeds should be collected when fully matured.

It should be emphasized that these are very general rules for
the guidance of the collector, and that when one is farming drug
plants this question becomes exceedingly vital, as not only do the
constituents vary at different times during the season, but there
is considerable variation in the amount of drug obtained. The
exact information regarding the proper time of gathering any
47

738 A TEXT-BOOK OF BOTANY.

specific drug can be obtained only by collecting it at different
times during the season, assaying it and making preparations
from it. Experiments thus far seem to show that belladonna
leaves collected in July and August show a higher toxicity than
those gathered in September or October. It is quite possible that
after the removal of the leaves high in alkaloidal content in July,
another crop can be obtained by October. It is important to bear
in mind with some drugs that a very slight difference in time of
gathering and manner of drying, great variation of the active con-
stituents may be found, as with many of the Composite flowers.
It is only when they are in the bud condition, as in the case of
insect flowers, and santonica, that they show the highest amount
of active principle. Again, depending on whether an article is
gathered to be put upon the market or whether the active prin-
ciples are to be isolated, as in the manufacture of the essential
oils, different methods are followed, depending upon the nature of
the plant and what previous experiments have demonstrated
should be followed. For instance, while in the preparation of oil
of peppermint the herb is first dried, yet in other cases the col-
lected material must be previously macerated in order to obtain
the largest yield of oil, as with those plants yielding volatile oils
containing either cyano-benzaldehyde or methyl-salicylate.

Too much attention cannot be given to the entire question
of the harvesting of the crop and proper methods of drying, and,
of course, again, depending upon the locality, different methods
will be followed. There are some places at certain times where
it would be quite possible to dry the drugs out of doors. In other
situations it would be necessary to dry them in barns and even
in specially constructed drying ovens* where artificial heat would
be employed. The drying oi leaves, flowers, and seeds is com-
paratively simple and can usually be rather quickly performed
without any special preparation. In the case of roots and fleshy
fruits the drying should be under special protection, and is facili-
tated more or less by slicing or comminuting the article.

In some drugs, in addition to drying, there is a curing process
that takes place. By this process of fermentation the active con-
stituents are developed. Among the drugs treated in this manner
the following may be mentioned : tobacco, vanilla, gentian,

CULTIVATION OF MEDICINAL PLANTS. 739

guarana, digitalis, the Solanaceous leaves, etc. In some cases
the increase in quality can be determined by the assay of some one
constituent, but in other cases the acquired value, like that of teas,
wines, and tobacco, cannot be determined by an assay process and
yet can be detected by the expert.

It has already been pointed out that plants contain a large
proportion of water, and when they are collected and dried there
is necessarily considerable loss. The loss is greater in the case
of herbaceous plants, where the yield of crude drug is only about
10 per cent., as in eupatorium and stramonium. Roots and rhi-
zomes yield on an average from 20 to 30 per cent, of dried drug.
In some cases, as in hops, the yield of dried drug is over 60 per
cent., and in fruits and seeds there is very little loss.

RELATIVE VALUE OF DRUGS FROM CULTIVATED AND WILD
PLANTS. — For some years it has been a question whether the
activity of drugs obtained from cultivated plants is equal to that
of those derived from wild plants. We find in some of the
foreign pharmacopoeias the specific statement that certain drugs,
as digitalis, belladonna leaves, and belladonna root, must be
derived from wild plants. This would naturally lead to the infer-
ence that wild plants are better, and yet it may be that this
provision was made with the intention of securing uniformity
of drugs rather than because the materials from wild plants are
superior. In 1907 Rippetoe conducted some experiments in Vir-
ginia which showed that cultivated plants of belladonna yielded
both leaves and roots which were equal, if not superior, to the
average drug on the market. As this work was done without any
particular care and in a limited way, it was more than gratifying
to those who were especially interested in this subject. Carr has
shown by careful comparative experiments that cultivated plants
of belladonna contain a little more alkaloid than do the wild
plants. The investigations of Sievers also point to a similar
conclusion. Sievers has also shown that the percentage of alka-
loids in the leaves of different cultivated plants is exceedingly
large, and that plants high in alkaloids will continue to breed
plants high in alkaloids, so that by mere selection a better com-
mercial article may be produced. Coming to the question of
digitalis, there are some very interesting results. Hale, for in-

740

A TEXT-BOOK OF BOTANY.

stance, showed that cultivated digitalis leaves yield a much higher
potency than those obtained from wild-grown plants, and yet
he concludes that it is doubtful whether the fact that they were
cultivated had anything to do with the high activity. One of the
most valuable facts brought out in connection with these experi-
ments is that the leaves of one-year-old plants seem to have as great
toxicity as those of the two-year-old plants. Hale distinctly states
that " first-year leaves are not necessarily weaker than second-

FlG. 408. Atropa Belladonna, first year's growth from seed planted January ist.
Photograph in July of the same year. — From the Experimental Farm of Eli Lilly & Com-
pany, Indianapolis, Ind.

year leaves, and might be used in preparing assayed digitalis prepa-
rations." This means that one does not have to wait two years
before securing a crop, so that practically one can obtain twice the
quantity of the drug during the same period.

There may be some instances during this experimental stage
which might seem to indicate that certain external conditions, such
as climate as well as soil, have a very great influence in the growing
of plants o<f exceptional value. In the case of American-grown
cannabis, Eckler and Miller have shown that repeated plantings

CULTIVATION OF MEDICINAL PLANTS. 741

from carefully selected plants of American and Indian cannabis
have failed to yield, when in cultivation near Indianapolis, a
product testing over 65 per cent, of the active value of good
Indian-grown drug, and that the majority of the plants tested
50 per cent, and even less.

FlG. 409. Form of American Cannabis developed by F. A. Miller. Such forms are
obtained by selection and result in strains that are better adapted to modern methods of
agriculture and from which the collection of the pistillate inflorescence is greatly simplified. —
From the Experimental Farm of Eli Lilly & Company, Indianapolis, Ind.

Experiments conducted near Timmonsville, S. C, by the U. S.
Department of Agriculture have shown that in that locality a
drug of a somewhat higher degree of potency can be grown. Of
course, it is well known that the hemp plant is grown extensively
for fiber in Kentucky and other parts of the middle West. This

742

A TEXT-BOOK OF BOTANY.

may be due in large part to the fact that it requires a limestone soil,
and in practice the most favorable results are obtained where there
is an underlying bed of blue limestone. Sufficient has been said
to show that success will attend the cultivation of medicinal
plants, and indeed, by a priori reasoning on the basis of other

FlG. 410. Form of American Cannabis developed by F. A. Miller. Such forms are
obtained by selection and result in strains that are better adapted to modern methods of
agriculture and from which the collection of the pistillate inflorescence is greatly simplified.
— From Experimental Farm of Eli Lilly & Company, Indianapolis, Ind.

agricultural efforts, one would expect that medicinal plants could
be grown with the same certainty of increasing the yields of any
particular constituent or quality that might be desired. Indeed,
the history o<f the sugar beet industry has been duplicated in the
work on Cinchona, and the same thing can be said with regard to
any other plant that man desires to conserve and cultivate. There

CULTIVATION OF MEDICINAL PLANTS. 743

are no insurmountable obstacles in this work, and there are no in-
tricate processes to be solved before success results. There are
merely a few underlying principles that must be adhered to, and
by persistent effort and with a full understanding of market con-
ditions success must crown the efforts of anyone who undertakes

FIG. 411. A seedling plant of Digitalis about six months old.

this work. What has been done in the selection of fruits and vege-
tables can be equally well accomplished in drugs with the proper
incentive.

PROGRESS IN THE UNITED STATES. — We can scarcely appreciate
that, while the development of medicinal plant culture has been

744

A TEXT-BOOK OF BOTANY.

an exceedingly slow one, yet as a matter of fact, by reason of
some of the products being more extensively used, as in the case
of hops, it is one of the oldest agricultural industries in the United
States. The history of the cultivation of hops is very similar to

FIG. 412.

Cannabis sativa: Young plant grown from seed found in the drug Cannabis
indica.

the experience with other medicinal plants. For instance, it was
grown in Virginia with poor results, and in Vermont and Massa-
chusetts, where it was very successful. By virtue of the success
obtained in the New England States it was, in the early part of
the last century, introduced into New York State and later spread

CULTIVATION OF MEDICINAL PLANTS. 745

into some of the Middle States, as Michigan, Wisconsin, Indiana,
and Ohio. Since that time the cultivation has been extended to

FIG. 413. Seedling plants of Erythroxylon Coca (A) and Eucalyptus globulus (B).

some of the States on the Pacific coast, notably Oregon, Washing-
ton, and northern California.

The peppermint industry shows a similar history. This indus-
try was first developed in Wayne County, New York. Later it

746 A TEXT-BOOK OF BOTANY.

spread into Michigan, Ohio, and some of the Southern States,
and by reason of the more favorable climate and soil conditions
in Michigan the industry here has outstripped that of even New
York State, being practically .abandoned in Ohio and the other
States. The men connected with the Division of Botany of the
United States Department of Agriculture have always mani-
fested a keen interest in the possibilities of the cultivation of
medicinal plants, and have done what they could to encourage
interest in this subject, and the records show that they have sup-
plied in formation as it might be needed by those disposed to take
up the work in a practical manner.

The development of the tea industry in North Carolina is
one of the most creditable pieces of work of the National Govern-
ment. Bulletin No. 234 of the Bureau of Plant Industry, on " The
Cultivation and Manufacture of Tea in the United States," by
George F. Mitchell, should serve as an inspiration to anyone
contemplating drug culture. If a plant of this kind can be grown
successfully here and the technique of manufacture developed
to such an extent that the cultivation at Pinehurst, North Carolina,
has become remunerative, there is no question but that within
reasonable limits nearly any plant except the strictly tropical ones
can be successfully grown in the United States.

Without doubt, the camphor industry will become successful
in some of the Southern States. Nearly fifty years ago, when the
price of camphor was very high, the government started some
experiments in Florida in the growing of the camphor tree. These
experiments were subsequently abandoned, as there was hardly
any likelihood of anyone being interested in this commercially
on account of the low price of camphor. During the past few
years, however, interest in this culture has been revived in Florida
and southern Georgia.by reason of the fact that frosts destroyed the
citrus fruits and the landowners began a search for other possible
crops which would not be so injured. Circular No. 12, Division
of Botany, United States Department of Agriculture, shows just
what can be done for the successful cultivation of this tree in the
Southern States, and some recent experiments of the government
show that by utilization of leaves and twigs there are great possi-
bilities in the economical manufacture of camphor in the United
States in spite of the high price of labor.

CULTIVATION OF MEDICINAL PLANTS. 747

Owing to the fact that essential oils are used in such large
quantities it is quite likely that the cultivation of many of these
plants may be made successful, providing at the same time that
suitable apparatus for their distillation is also installed upon the
farms.

By reason of the fact that the cultivation of chicory is a per-
manent agricultural industry in nearly all of the countries having
a temperate climate in Europe, experiments have been conducted
in the United States in a small way, and these have led to the con-
clusion that it may be successfully cultivated in those States where
the sugar beet industry has flourished.

As a summary, the following general points might be held in
mind by those who desire to take up the cultivation of medicinal
plants :

In the first place, he ought to determine whether there is a
market for any drug under consideration, and this can only be
obtained by personal inquiry and investigation, as not even any
of the government publications give this information.

In the next place, if one is satisfied that it is worth while
to take up the cultivation of any particular plant, its geographi-
cal range should be studied, both as to where it is indigenous
and where it has become naturalized. The literature should be
gone over not only for facts regarding the cultivation and distribu-
tion of the particular plant in view, but also of some of the related
plants.

At the same time that these preliminary studies are made, a
careful survey should be taken of the plants which are indigenous
and under cultivation in the particular locality where one is pro-
posing to locate the farm. Then, of course, everything should
be done on a small scale at first. If there is no information
available, then he must, on the basis of the general principles laid
down for the cultivation of medicinal plants, proceed with their
culture, conducting parallel experiments with propagation by both
seeds and cuttings.

Then when the crop is harvested he must, by analytical and
other means, satisfy himself as to the value of his product com-
pared with the commercial article, and with these facts in hand
submit specimens and request quotations from the dealer in crude
drugs, and the wholesale druggist. On this basis he will arrange

748 A TEXT-BOOK OF BOTANY.

for all future crops with some certainty as to their market value.
Experience has shown that cultivated crops command a higher
price than the drugs obtained from wild plants, even though their
superiority cannot always be demonstrated by analytical means.
For instance, no one is trying to determine by an analytical process
whether any given lot if tobacco, tea, or coffee is of superior value,
and yet the competent dealer and the discriminating public even
recognize the qualities of the grades that are offered. This is
even more marked with the products that have been derived thus
far from cultivated medicinal plants, and are appreciated by some
pharmacists and physicians.

BIBLIOGRAPHY.

CULTIVATION OF BELLADONNA : A. F. Sievers, Amer. Jour. Pharm., March
and November, 1914; Francis H. Carr, Ibid., November, 1913; F. A.
Miller, Ibid., July, 1913.

CULTIVATION OF DIGITALIS: E. L. Newcomb, Amer. Jour. Pharm., No-
vember, 1911 ; John A. Bornefnan, Ibid., December, 1912; F. A. Miller,
Ibid., July, 1913.

CULTIVATION OF HYDRASTIS : John Uri Lloyd, Proc. A. Ph. A., 1905, p. 307,
and in Jour. A. Ph. A., Vol. I, p. 5; Alice Henkel and G. Fred.
Klugh, Circ. No. 6, Bureau of Plant Industry, U. S. Department of
Agriculture; J. C. Baldwin, Amer. Jour. Pharm., April, 1913.

CULTIVATION OF GINSENG : George V. Nash, Bulletin No. 16, Division of
Botany, U. S. Department of Agriculture.

CULTIVATION OF EUCALYPTUS : A. J. McClatchie, Bulletin No. 35, Bureau
of Forestry, U. S. Department of Agriculture.

CULTIVATION OF PEPPERMINT: A. M. Todd, Proc. A. Ph. A., 1903, p. 277;
Alice Henkel, Bulletin No. 90, Bureau of Plant Industry, U. S. De-
partment of Agriculture.

CULTIVATION OF CANNABIS SATIVA : C. R. Eckler and F. A. Miller, Amer-
Jour. Pharm., November, 1912.

CULTIVATION OF CAMPHOR : Circ. No. 12, Division of Botany, U. S. De-
partment of Agriculture.

CULTIVATION OF TEA : Bulletin 234, Bureau of Plant Industry, U. S. De-
partment of Agriculture.

CULTIVATION OF CHICORY: Bulletin No. 19, Division of Botany, U. S.
Department of Agriculture.
A number of valuable articles by Mitlacher and other members of the

pharmacognostical department of the University of Vienna have been

published in Zeitschrift fur das landwirtschaftliche Versuchswesen in.

Oesterreich since 1911.

CHAPTER VII.
MICROSCOPIC TECHNIQUE AND REAGENTS.

MAKING OF SECTIONS. — In order to examine objects by means
of the compound microscope they must be relatively thin and
transparent ; furthermore, they must be mounted in water or other
mounting fluids. In material consisting of single cells, or, at
most, a layer of a few cells, the specimen may be mounted directly
in water. This manner of mounting may also be used in the exam-
ination of pollen grains, hairs, and thin organs, as petals. Usually
in the examination of the latter some clearing agent, as solution of
hydrated chloral, is necessary in order to make the specimen trans-
parent. As most objects consist of a large number of cells, it is
necessary to examine small portions of them, and these are termed
sections. They are made with a razor and correspond to the shav-
ings made by a carpenter's plane. As each object has three dimen-
sions, it is necessary that three different kinds of sections be made.

1 i ) A transverse or cross section is one made horizontally through
the object, therefore its plane lies at right angles to the long axis*

(2) A radial-longitudinal section is one made at right angles to the
cross section and it lies in the plane of the radius, so that in a
dicotyledonous stem the section would be made parallel with the
medullary rays. (3) A tangential-longitudinal section differs
from the preceding in that it lies parallel to the outer surface of
the object, or in a plane tangent to the cylinder. These several
forms of sections are readily understood from the adjoining illus-
tration (Fig. 414).

Sections of roots, stems, barks, and many fruits and seeds
can be made directly without embedding the material, and while
sections can be made holding the material in the hand, between
the thumb and three fingers, the hand microtome for holding
the material may be used by those who are less experienced. In
the sectioning of leaves and other material that is not firm, and
fruits and seeds which are too small to hold in the hand, the
material should be embedded in some substance which will hold
it and give it stability. When the tissues are not too hard the

749

750

A TEXT-BOOK OF BOTANY.

material may be placed between pieces of elder or sunflower pith.
In some cases the making of sections is facilitated by moistening
both the pith and the razor. In the case of seeds and fruits which
are very small and at the same time very hard, as colchicum and
mustard, it is best to use a velvet or fine grade of cork for holding
the material. The cork is indented by means of forceps and the
seed or fruit forced into the cavity.

In the case of very delicate tissues, where the protoplasmic
contents of the cells are to be studied, as in the ovaries of flowers,
prothalli of ferns and other parts of the plant, where cell division,
is going on, the material should be embedded in paraffin or celloi-

FIG. 414. Schematic presentation of the three types of sections: q, cross or transverse sec-
tion; /, radial-longitudinal section; /, tangential-longitudinal section. — After Meyer.

din, subsequently hardened, and sectioned by means of a finely
adjusted microtome.

DRIED MATERIAL. — Most of the vegetable drugs and some of
the vegetable foods occur in commerce in a more or less dried
condition, and in order to study them microscopically it is usually
necessary to give them some preliminary treatment. With the
majority of drugs, soaking in hot or cold water from a few
minutes to a few hours will render them sufficiently pliable or
soft for sectioning. After this the material is hardened by placing
it in alcohol (60 to 70 per cent.) for a few hours or over night.
It may then be sectioned and treated with special reagents or
stains as desired. Very hard material, as the shells of nuts and

MICROSCOPIC TECHNIQUE AND REAGENTS. 751

seeds, may be softened by soaking in solutions of potassium
hydrate.

SOME PRACTICAL SUGGESTIONS. — The following are some
of the rules which should be bo-rne in mind by the student
when using the microscope in the examination of microscopic
material :

1. Always mount the sections (including powdered material)
in water or other suitable reagent prior to examination; never
attempt to examine dry material except in special cases.

2. Use sufficient of the mounting medium or reagent to cover
the specimen, but avoid an excess or more than will be held under
the cover-glass.

3. Always endeavor to have the object properly illuminated
by making use of the concave mirror.

4. Always be particular about having the eye-piece and objec-
tives clean.

5. In examining a microscopic object, always use the low-
power objective first.

6. The edge of a section is always the thinnest, and this part
being the best for study, should be brought to the center of the
field.

7. When the object is properly centered, raise the objective,
swing it to one side, bring the high-power objective into its place,
and cautiously lower it until it is brought to about the distance
of a millimeter from the cover-glass. Then holding the slide
with the left hand, the proper focus of the object is obtained by
making use first of the coarse adjustment and then of the fine
adjustment, the right hand being used fo-r this purpose. In exam-
ining the object always hold the slide with the left hand, and
use the right hand for maintaining the proper focus by means of
either the coarse or fine adjustment.

8. In all cases where practicable make drawings of the sections
examined.

9. In some cases it is desirable to apply a reagent after the
material has been mounted, as in the addition of an iodine solution
to a section to determine the presence of starch, and this is accom-
plished by placing a drop or two of the reagent, by means of a
pipette or dropper, near the edge of the cover on one side and

752

A TEXT-BOOK OF BOTANY.

taking up the excess of liquid by temporarily placing a piece of
filter paper on the opposite side (Fig. 415).

AIR-BUBBLES. — The beginner in the use of the microscope is
often confused by the presence of air-bubbles, mistaking them
for portions of the material under examination, as starch grains,
oil-globules, or even the cells themselves. While it is not prac-

FIG. 415. Method of applying reagent to material already mounted, g, pipette; f,

filter paper.

ticable to avoid their presence entirely, their identity may be
determined by the manner of focussing upon them. When
focussing above on an air-bubble it always appears dark (Fig.
416, C), but when the focus is lowered, it becomes lighter (Fig.
416, D) ; while in the case of an oil-globule or starch grain the
reverse is true, i.e., it is lightest when the focus is above (Fig.

MICROSCOPIC TECHNIQUE AND REAGENTS. 753

416, E) and darker when the focus is lowered (Fig. 416, F).
To obviate as much as possible the formation of air-bubbles, the
edge of the cover-glass should first be applied to the liquid on one
side and then allowed to drop upon it. When particular care is
required, a pair of forceps may be used for holding the cover and
lowering it gradually.

FIG. 416. Diagrams showing the difference between an air-bubble and an oil-globule
in different foci: When the focus is above, as at A, the air-bubble (C) is dark gray and
the oil-globule (E) light gray. When the focus is at the lower portion, as at B, the air-
bubble (D) is light in the center and the oil-globule (F) dark gray. The same optical effects
as are obtained with oil-globules are observed with cell walls, starch grains and crystals.

Frequently also simple pores in the cell-walls are mistaken
for cell-contents, and sometimes even the lumen of the cell has
been mistaken for a prism of calcium oxalate. The beginner
will therefore find it an advantage to study the simple pores in
the pith cells of elder or sassafras (Fig. 132). In sections show-
ing either the upper or lower wall of the cells, the pores appear
as circular or elliptical markings, which may be mistaken for cell-
48

754

A TEXT-BOOK OF BOTANY.

contents, but which in focussing upon them are seen to be optical

or microscopical sections of the pores.

MICROMETRY OR MICROSCOPIC MEASUREMENT. — In the micro-
scopic study of any substance a knowl-
edge of the comparative size of the
elements is often of much help in deter-
mining the identity of material under
examination, and for this reason the
student should early learn to measure the
characteristic elements, or those showing
a variation in size in different plants, as
starch grains, calcium oxalate crystals,
diameter of cells, thickness of cell-walls,
etc. The method best adapted for this
work is that involving the Use of a micro-
metric scale which is placed in the eye-
piece and known as the ocular micrometer.
But to determine the value of the ocular
micrometer it is necessary to use another
scale known as the stage micrometer.
The stage micrometer, as its name indi-
cates, is used on the stage, and when
placed in juxtaposition to an object indi-
cates its size. However, it is obviously
impracticable always to place an object

alongside of the scale, and hence in prac-

Cjhit^ _...^ tice the ocular micrometer is used, the

value of the divisions of which are

of determined by comparison with those of

the ocular micrometer (o) and ..i • /T-" \ TM

the stage micrometer (s). AS the stage micrometer (Fig. 417). The

here represented 20 divisions 1 r j_i j' • • r j.i 1 1

of the ocular scale are equiva- Value of the divisions of the OCUlar Scale
lent to 4 divisions of the stage • e j • rr i • , •

micrometer, and thus each di- vanes for different objectives, eye-pieces

vision of the ocular is equiva- 1^.11 ^i 1 •, •

lent to 2 microns (see p. 8i3). and tube lengths, hence it is necessary to

d, diaphragm in eye-piece, , • ,1 i f ,1 «... r .

on which the ocular microm- ascertain the value of the divisions for the
different optical combinations and tube

lengths employed. The stage micrometer is usually divided into
tenths and hundredths of a millimeter, and the millimeter being
equivalent to 1000 microns (the micron being indicated by the

MICROSCOPIC TECHNIQUE AND REAGENTS. 755

Greek letter ^u.), the smaller divisions are equivalent to 10 microns
(io/x). For example, suppose, using a low-power objective,
that 10 divisions of the ocular scale equal 20 of the smaller
divisions of the stage micrometer. Thus, 20 divisions of the stage
micrometer are equivalent to 20 times IO/A , or 200 /x; then, since
10 divisions of the ocular scale equal 20 divisions of the stage
micrometer, one division of the ocular scale is equivalent to i/io
of 200 /x, or 20 fji. Or, using the high-power objective, we may
suppose that 80 divisions of the ocular scale equal 24 divisions of
the stage micrometer. Thus, I division of the ocular micrometer
is equivalent to 1/80 of 240 /z, or 3^. Then, if an object has a
diameter covering 3 divisions of the ocular micrometer, its diame-
ter is equivalent to 3 times 3 /* (the value of one division), or 9 p.

REAGENTS. — The reagents that have been recommended for
microscopical work are quite numerous, and, while nearly all o-f
them may have more or less special merit, the number of reagents
actually required in practice is fortunately quite small.

It is important that the student recognize the necessity for a
thorough understanding of the structure of the material under
examination rather than place too much dependence upon the
effects produced by reagents ; in other words, the study of struc-
ture should precede the use of reagents, particularly stains, when
it will often be found that the latter can be dispensed with entirely.

The chemicals that are employed in microscopical work, either
as reagents or for other purposes, may be classified as follows:
(i) Preservatives, (2) Fixing and Killing Agents, (3) Harden-
ing and Dehydrating Agents, (4) Clearing Agents, (5) Stains,
and (6) Special Reagents.

PRESERVATIVES are substances used to preserve material which
is to be examined. The most important of these are alcohol ( from
40 to 95 per cent.) and formalin [2 to 6 per cent, aqueous or
alcoholic (60 per cent, alcohol) solution], the latter of which is
considered advantageous in the preservation of specimens contain-
ing coloring substances, as leaves, flowers, etc. Almost any anti-
septic of the proper strength may be used as a preservative.

FIXING or KILLING AGENTS are more especially employed in
the study of the protoplasmic cell-contents, where by their use
the life-processes of the cell are brought to a sudden termination,

756 A TEXT-BOOK OF BOTANY.

the object being to fix the contents in a condition approaching as
nearly as possible the normal living state. In order to carry out
this operation successfully, the living specimen must be placed in
the fixing or killing agent as soon as collected, and if the specimen
is large it should be cut into small pieces. The following are some
of the common fixing agents : Chromic acid in 0.5 to i per cent,
aqueous solution ; osmic acid in i to 2 per cent, aqueous solution ;
Flemming's mixture, which is an aqueous solution of chromic
acid (0.25 per cent.) containing o.i per cent, of osmic acid and
o.i per cent, of acetic acid; picric acid in concentrated aqueous
or alcoholic solution ; picric-sulphuric acid, a concentrated aqueous
solution of picric acid containing 2 per cent, by volume of sulphuric
acid; and mercuric chloride (corrosive sublimate) used in o.i to
i per cent, aqueous or alcoholic solution.

HARDENING or DEHYDRATING AGENTS are those substances
which are employed for the purpose of hardening the specimen so
as to facilitate sectioning and for removing the water, which
would interfere with its examination. Alcohol is to be regarded
as the principal hardening or dehydrating agent, and considerable
care is necessary in its use; the specimen is treated successively
with alcoholic solutions of gradually increasing strength, begin-
ning with a 35 per cent, solution, in which the specimen is kept
for twenty-four hours ; then it is placed in 50 per cent, alcohol for
from six to twenty-four hours, and then in 70 per cent, alcohol,
in which it may be kept until ready for use. In order to avoid
shrinking of the material at this stage, it may be kept in a solu-
tion of alcohol and glycerin, or oil of bergamot, or a mixture of
xylol and paraffin. When the material is to be examined it should
be removed to 85 per cent, alcohol for from six to twenty- four
hours, then to 95 per cent, alcohol and absolute alcohol suc-
cessively for the same length of time. Of the other dehydrating
agents the most important are anhydrous glycerin, pure carbolic
acid, and anhydrous sulphuric acid, the latter being used in a
desiccator and not applied directly to the specimen.

CLEARING AGENTS. — Most dehydrating agents are also clear-
ing agents, because of the fact that the air and water in the speci-
men are replaced by a medium having greater refractive proper-
ties. Some clearing agents act chemically on the tissues and cell-

MICROSCOPIC TECHNIQUE AND REAGENTS. 757

contents. Among the clearing agents most frequently employed
are: Chloral in saturated aqueous solution, and chloral-glycerin
solution (a solution of equal parts of glycerin and water saturated
with chloral). Essential oils, as clove, turpentine, cedar, mar-
joram, etc., are also useful for this purpose, particularly when
the specimen is to be mounted in Canada balsam.

STAINING AGENTS are those that produce more or less defi-
nitely colored compounds with the cell-contents or -walls. They
include: (i) the Aniline Dyes and (2) Non-aniline Stains.

The aniline stains may be used in aqueous solutions, weak
alcoholic solutions or strong alcoholic solutions, containing from
i to 3 per cent. o>f the dye. The following are the aniline stains
most frequently employed : Aniline blue, Bismarck brown, fuchsin,
gentian violet, methylene blue, methyl violet and safranin. In
addition to these, aniline hydrochloride or sulphate is used in what
is known as Wiesner's Reagent, which is a 25 per cent, solution of
alcohol containing 5 per cent, of either of these salts, a drop of
either hydrochloric or sulphuric acid being used with a drop of the
solution, according as the hydrochloride or sulphate has been used.

LOFFLER'S METHYLENE BLUE. — This reagent is prepared by
adding 30 c.c. of a concentrated alcoholic solution of methylene
blue to 100 c.c. of water containing 10 milligrams of potassium
hydrate.

ZIEHL'S CARBOL-FUCHSIN. — This solution is prepared by add-
ing 15 c.c. of a concentrated alcoholic solution of fuchsin to
100 c.c. o>f water containing 5 grams of carbolic acid.

ANILINE DYES are usually employed in concentrated aqueous
solution, but owing to the difference in solubility of the dyes the
solutions vary in strength. Saturated solutions of eosin or gen-
tian violet may be prepared by dissolving i gram of the dye in
100 c.c. of water, while to make a saturated solution of methylene
blue requires 0.400 Gm. of the dye to 100 c.c. of water. Some
investigators prefer to replace the distilled water with aniline
water, which is prepared by adding about 3 grams of anilin oil to
loo c.c. of distilled water.

REAGENT BOTTLE FOR STERILE SOLUTIONS. — The solutions of
the aniline dyes as ordinarily prepared deteriorate more or less
rapidly and are usually made up fresh each time they are required

758

A TEXT-BOOK OF BOTANY.

for use. These solutions, as well as other reagents that are prone
to decomposition, may, however, be kept for months or even years
by preparing them with care and keeping them in a special kind
of bottle (Fig. 418). An ordinary bottle may be used, and is
fitted with a rubber stopper perforated so as to allow the intro-
duction of two glass tubes. These tubes are bent twice at right
angles and the free ends directed downwards. One of the tubes
is connected with an atomizer bulb and serves for forcing out the

FIG. 418. Reagent bottle for sterile solutions.

liquid. A small plug of absorbent cotton is placed in the tube
at the point C, so as to filter the air. This may be improved by
blowing a bulb in the tube for holding the cotton. The bottle
should be sterilized before placing the solution in it, and the solu-
tion should be made by adding the dye to sterile water contained
in the bottle. The solution may be afterwards further sterilized
by means of steam if this should be found necessary, as in this
way only a perfectly sterile solution could be produced.

MICROSCOPIC TECHNIQUE AND REAGENTS. 759

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760 A TEXT-BOOK OF BOTANY.

The non-aniline stains give, as a rule, more reliable and con-
stant results in the study of cell-walls, as in the roots, stems, and
other parts of the plant, than the aniline stains. They include
the following:

BEALE'S CARMINE SOLUTION, which is made as follows : Mix
0.6 Gm. carmine with 3.75 Gm. ammonia water (10 per cent.) ;
heat on a water-bath for several minutes ; then add 60 Gm. o-f
glycerin, 60 Gm. of water and 15 Gm. of alcohol, and filter.

GRENACHER'S BORAX-CARMINE SOLUTION. — Dissolve 2 to 3
Gm. of carmine and 4 Gm. of borax in 93 c.c. of water and then
add 100 c.c. of alcohol (70 per cent.) ; shake and filter. When
this stain is employed the sections are freed from an excess by
the use of alcoholic solutions of borax or oxalic acid.

HOVER'S PICRO-CARMINE SOLUTION is made by dissolving
carmine in a concentrated solution of neutral ammonium picrate.
A solution of carmine and picric acid is known as Picro-Carmine
Solution. Carmine solutions give to cellulose, the nucleus and
proteins a red color.

CHLOR-ZINC-IODIDE SOLUTION, or Schulze's Cellulose Reagent,
consists of anhydrous zinc chloride, 25 Gm. ; potassium iodide, 8
Gm., and water, 8.5 Gm., to which as much iodine is added as
the solution will dissolve. This reagent gives a violet color with
cell-walls containing cellulose. Of the cell-contents, starch is the
only one which is affected by it, being colored blue.

BOHMER'S HJEMATOXYLIN SOLUTION is prepared by mixing
Ithe two following solutions and filtering after allowing the mix-
ture to stand for several days: (a) one part of a 3.5 per cent,
alcoholic (95 per cent.) solution of hsematoxylin and (b) three
parts of a 0.4 per cent, aqueous solution of potassium alum.

DELAFIELD'S H^MATOXYLIN SOLUTION, which is also incor-
rectly called " Grenacher's Hsematoxylin Solution," is made by
mixing the following solutions: (a) Hsematoxylin 4 Gm., alcohol
25 c.c., and (b) 400 c.c. of a saturated aqueous solution o>f ammo-
nia alum ; this solution is exposed to the light for three or four
days, filtered, and then 100 c.c. each of glycerin and methyl alco-
hol are added, the solution allowed to stand for several days and
finally filtered. An excess of the stain is removed from the sec-
tions by subsequent washing either with a 2 per cent, alum solution

MICROSCOPIC TECHNIQUE AND REAGENTS. 761

or an acidified alcoholic solution. This solution gives to cellulose,
lignin and the protoplasmic cell-contents a violet color.

IODINE AND POTASSIUM-IODIDE SOLUTION consists of iodine,
2 Gm. ; potassium iodide, 6 Gm. ; water, 100 c.c.

IODINE WATER is prepared by adding as much iodine to dis-
tilled water as it will dissolve (about i : 5000).

CHLORAL-IODINE SOLUTION consists of a saturated aqueous
solution of chloral, to which iodine is added. This reagent is
useful for staining the starch grains in the chloroplasts.

PHLOROGLUCIN SOLUTION, used as a test for lignin, is a 0.5
to 2 per cent, alcoholic solution of phloroglucin, which is used
in conjunction with hydrochloric acid. The reagent should be
protected from light.

IRON SOLUTIONS are aqueous or alcoholic solutions containing
5 to 20 per cent, of ferric acetate or ferric chloride. These are
mostly used as tests for tannin, giving either a bluish-black or
greenish-black coloration or precipitate.

COPPER-ACETATE SOLUTION is a j per cent, aqueous solution
of cupric acetate. It is the most distinctive test for tannin, par-
ticularly with fresh material, producing a reddish-brown precipi-
tate in the cells containing tannin. The fresh material should be
cut into small pieces and immediately placed in the solution of
copper acetate and allowed to remain for from 24 to 48 hours.
The excess of the reagent is then washed out and the material
placed in alcohol.

SCFULZE'S MACERATING SOLUTION is prepared by adding
crystals of potassium chlorate from time to time to warm con-
centrated nitric acid. It is employed in the isolation of lignified
cells. The material is allowed to remain in the solution for a
short time or until there appears to be a disintegration of the
tissues. A large excess of water is then added. The material is
carefully washed, the cells teased apart and mounted in a solution
of methyl ene blue.

SPECIAL REAGENTS comprise all those substances which are
employed in the morphological study of the cells, and include
solutions of the alkalies (o.i to 6 per cent.) solutions of the
mineral acids, which may be weak or concentrated, and solutions
of organic acids, as acetic and citric.

762

A TEXT-BOOK OF BOTANY.

DOUBLE STAINING, or the use of two stains in the examination
of a specimen, furnishes not only a means of beautifying the speci-
men, but also has a certain diagnostic value. The following are
some of the combinations used: (a) aqueous solutions of car-
mine in connection with alcoholic solutions of iodine green; (b)

o

PlG. 419.. Crystals of some of the common reagents which not infrequently sepa-
rate on the slide and may be mistaken for cell contents: A, isotropic crystals of chloral
which occur in cubes about 10 /u. in diameter or long needles about 50 M long; B, phloro-
glucm which occurs in broad rectangular plates or ellipsoidal discs from 10 to 35 /u. in diam-
eter which are doubly refracting with a play of colors; C, cubes of potassium iodide which
&Te isotropic; D, crystals from potassium hydrate solution which separate in broad prisms
and branching chains that are doubly refracting and give marked color effects.

alcoholic solutions of hsematoxylin and safranin; (c) solutions of
eosin and methylene blue; (d) solutions of fuchsin and methylene
blue; (e) solutions of gentian violet and Bismarck brown.

MOUNTING OF SPECIMENS. — Microscopic preparations or
mounts are of two kinds: they may serve a temporary purpose

MICROSCOPIC TECHNIQUE AND REAGENTS. 763

only or they may be prepared so as to serve for future study,
the latter being known as PERMANENT MOUNTS.

In taking up the study of a specimen it should first be mounted
in water and examined ; then the water may be replaced by a weak
aqueous solution of glycerin (5 to 10 per cent.) and the specimen
examined again. After this preliminary examination other agents
and reagents may be employed. Specimens mounted in glycerin
will keep for several days and even months. Generally speaking,
the only effect which the glycerin has on the tissues or contents
is that of swelling them, which is obviated, to a greater or less
extent, however, if the glycerin is washed out after an exam-
ination is made.

In addition to the methods involving the use of glycerin, there
are two ways of making permanent mounts, depending upon the
employment either of Canada balsam or glycerin jelly as the
mounting medium. The method involving the use of the latter
is the simpler, and leaves the specimen in such a condition that a
re-examination with reagents can be made if desirable. GLYCERIN-
JELLY mounts are made as follows : Specimens which have been
previously treated are transferred to glycerin and allowed to
remain for several hours, the excess of glycerin removed, and
the specimen transferred to a warm slide on which a drop of
glycerin jelly * has been placed. The preparation is warmed
slightly to remove air-bubbles, and a warm cover-glass applied,
care being taken to prevent the formation of air-bubbles. Evap-
oration of the glycerin jelly is prevented by the use of shellac
cements, asphalt varnish or candlewax.

The following method may be used for the preparation of
CANADA BALSAM MOUNTS: The specimen is cleared, dehydrated
by the use of alcohol and then placed in chloroform or benzol. The
clearing of the specimen is materially assisted by placing it in
oil of cloves or turpentine prior to mounting it. A drop of Canada
balsam solution (i part of balsam to 3 parts of chloroform or

1 KAISER'S GLYCERIN JELLY. — Digest 7 Gm. of gelatin in 42 Gm. of
water for two hours on a hot water-bath ; dissolve i Gm. of carbolic acid in
49 Gm. of glycerin ; mix the two solutions ; heat on a water-bath, with
occasional stirring, for fifteen minutes, and finally filter through glass
wool. The jelly is warmed slightly to liquefy it before using.

764 A TEXT-BOOK OF BOTANY.

benzol) is placed on a slide and the specimen mounted. When
nearly dry, scrape off the excess of balsam, clean the slide and
cover-glass with chloroform or benzol, and ring with cement.

THE MICRO- POLARISCOPE is a useful accessory in conjunction
with the microscope. It is employed in the study of technical
products, and is chiefly applicable in the examination of crystals,
starch grains and cell-walls. A number of substances, owing to
certain peculiarities of structure, are double-refracting or ANISO-
TROPIC, i.e., they polarize light. If the double refraction is strong
enough these substances show a play of colors. Of these may
be mentioned the raphides and the rosette aggregates of calcium
oxalate, cane sugar, citric acid, benzoic acid, caffeine, salicin, aloin,
phloroglucin, and the salts of berberine, strychnine, and atropine.
The acicular crystals which separate in chloral preparations of
gambir also show a play of colors. Among the substances which
are anisotropic but give no chromatic effects are starch grains,
inulin, mannit, the rhombohedra in catechu and the various types
of cell- walls. All substances which form crystals belonging ta
the isometric system are ISOTROPIC or single-refracting, i.e., do
not polarize light, as sodium chloride, the octahedra in gambir,
potassium iodide and chloral.

When glass, which is an isotropic compound, is heated and
suddenly cooled it is changed into an anisotropic body. Micro-
scopic glass beads formed by quickly cooling very thin pieces of
glass show polarization effects similar to those of wheat starch
grains. This has led to the supposition that the polarization
effects produced by starch grains are due to tension rather than
to a crystalline structure. But this point cannot be definitely
settled until it has been determined whether any of the substances
composing the layers of the starch grains are capable of crystal-
lization.

THE SPECTROSCOPE IN MICROSCOPIC ANALYTICAL WORK. — To
a limited extent at the present time, and yet very effectively by
those who are competent to employ it, the Spectroscope is being
employed in the examination of organic coloring substances. This
method has the advantage that accurate results can be obtained with
small quantities of material. With the proper instruments and
with practice one may attain a skill equal to that attained in

MICROSCOPIC TECHNIQUE AND REAGENTS. 765

qualitative and quantitative analytical work. The Spectroscope
can be used in checking chemical methods and also employed
frequently in the detection of mixtures, just as the microscope is
used where qualitative chemical methods are not available. The
Spectroscope is used not only in the examination of single color-
ing principles, but where there are mixtures, and whether these
are in solution, on fabrics, on paper, etc. So that for technical
chemists, especially for those interested in dyeing and allied indus-
tries, it has a very great value.

. There are several different types of spectroscopes : ( I ) the
ordinary, in which the liquid is placed in a long glass cell between
the source of light and the slit of the spectroscope; (2) a com-
parison spectroscope, where an unknown liquid can be compared
with that of a known; (3) the micro-spectroscope, in which a
spectroscope is attached to a microscope and the liquid is placed
in small tubes.

A characteristic spectrum is obtained only when the solution
is of the proper dilution. The solutions must be prepared care-
fully and interfering substances removed as much as possible.

( Consult : " Untersuchung und Nachweis organischer Farb-
stoffe auf spektroskopischen Wege," by Jaroslav Formanek and
Dr. Eugen Grandmougin, Second Edition. " Zur Biologic des
Chlorophylls Laubfarbe und Himmelslicht Vergilbung und Etiole-
ment," by Ernst Stahl. " The Origin and Nature of Color in
Plants," Kraemer, in Proc. Am. Phil. Soc., 1904, p. 259.)

DARK FIELD ILLUMINATION AND THE ULTRA-MICROSCOPE. —
The study of minute particles which are otherwise not visible
under the microscope by direct illumination may be accomplished
by a simple contrivance known as a reflecting condenser. The
principle upon which this operates is similar to when a pencil
of sunlight enters a more or less darkened room, causing the par-
ticles of dust to become visible. In the same manner the invisible
particles in a colloidal solution and the ordinarily structureless
substances in an animal or vegetable cell are rendered visible by
reason of the contrast between these particles and their dark sur-
roundings.

The apparatus consists essentially of two parts : ( I ) a parab-
oloid condenser which has two reflecting surfaces so as to bring

766 A TEXT-BOOK OF BOTANY.

the rays of light to a focus on the objective and against a dark
background; and (2) a funnel stop objective. The latter is an
ordinary immersion objective with the addition of a funnel stop
back of the lenses so that the diffused rays only enter the eye to
the exclusion of the direct rays.

An ordinary microscope with a reflecting condenser and a
funnel stop objective thus constitutes an ultra-microscope. The
illumination is by means of an arc light. If a Welsbach lamp is
used it is necessary to employ a bull's-eye lens to concentrate
the light upon the mirror. The light is ordinarily reflected
through the condenser from the plane mirror of the microscope.
Cover-glasses of a standard thickness, 0.17 mm., should be used.
The space between the top of the condenser and the microscopic
slide containing the object must be rilled with a layer of cedar
oil in the same way as between the cover-glass and the objective.
Time must be taken to perfectly center the condenser with refer-
ence to the objective.

(Consult: " Dunkelfeldbeleuchtung und Ultramikroskopie,"
by N. Gaidukov.)

MICRO-ANALYSIS.

The value of the microscope is well established in the examina-
tion not only of the living plant but in the study of various techni-
cal products. It is usual to give greater prominence to the ANA-
TOMICAL or HISTOLOGICAL method of study, based largely upon
the form of cells and the structure and composition of their walls.
The study of cell contents, as starch grains, calcium oxalate>
phyto-globulins, and other definite substances, is being utilized
very largely in the examination of technical products and to some
extent by students of botany.

A number of books have been published dealing with the
micro-chemistry or histo-chemistry of some of these substances.
For the most part the study of microscopic crystals has been of
a very general nature, in that statements are given regarding
the general shape of the crystals or their aggregates and their
behavior with certain test solutions. The time has come when
the study of the crystalline substances found in plants requires,
if any real progress is to be made in this direction, that the

MICROSCOPIC TECHNIQUE AND REAGENTS. 767

CRYSTALLOGRAPHIC METHOD of examination be utilized. This
method originated in the examination of thin sections of rocks
and it has been possible by this study to* identify the numerous
rock-forming mineral species. In those species which are mixed
crystals, i.e., made up of isomorphous mixtures of two or more
components, it has been possible to determine with some accuracy
their composition simply by their optical properties, as for exam-

FIG. 420. Codeine: x-shaped skeleton crystals from TO per cent, alcoholic solution.

pie the feldspars. Furthermore, it has been possible to draw
conclusions as to the ultimate composition of rocks and the
conditions under which they were formed.

The value and possibilities of the employment of the crystal-
lographic method in biological studies is well exemplified in the
recent work of Reichert and Brown, " The Crystallography of
the Hemoglobins." By special means individual crystals of the
hemoglobins were obtained and by purely crystallographic
methods, including a study of the forms and optical properties
of such crystals, the hemoglobins of the 200 species of animals

768

A TEXT-BOOK OF BOTANY.

studied were differentiated in a manner that could not have been
accomplished by chemical analysis or other methods of procedure.
A careful study of much that has been written, and especially
of the illustrations that have been made, of micro-crystals in
plants and drugs, shows that erroneous conclusions may be easily
drawn from the general appearance of crystalline precipitates or
aggregates of crystals that are formed. For instance, Vogl has

FIG. 421. Cubebin: orthorhombic crystals from Prollius' solution, showing various
types of twinning (a, b, c); d, amorphous material in the form of oi.lv drops (under-cooled
liquid); e, this amorphous material crystallizing in aggregates.

shown that the sphero-crystals, found in the glandular hairs
of Mentha piperita and considered by some to be menthol, are
found in leaves of many of the Labiatae. Again, very many sub-
stances produce aggregate groups which closely resemble each
other, as of citric acid, cocaine hydrochloride, etc.

In regard to the value of the crystallographic method we
quote the following paragraph from Brown (loc. cit.) : "When
a chemical compound solidifies from fusion, solution or vapor
under conditions which are favorable to the development of

MICROSCOPIC TECHNIQUE AND REAGENTS. 769

individuals, its particles tend to arrange themselves in regular
order, so that a definite structure is produced. The external
form of the individuals is also regular, being bounded by planes
in definite relation to each other so that polyhedral solids are
produced which are called CRYSTALS. The regular arrangement
of the atoms among themselves, and of the molecules which

FIG. 422. Strychnine sulphate: tetragonal crystals in polarized light, showing side aspect.

they build up, is so characteristic of substances of definite com-
position that the crystalline condition of dead matter is the normal
condition. Differences in chemical constitution are accompanied
by differences of physical structure, and the crystallographic test
of differences of chemical constitution is recognized as the most
delicate test of such differences."
49

770 A TEXT-BOOK OF BOTANY.

It is apparent that, apart from their solubility, color reactions,
behavior towards reagents, etc., the substances with which we
are dealing should be prepared in such a manner that isolated
crystals are formed and not aggregates or groups. These isolated
crystals can then be studied independently. The reason why

FIG. 423. Hydrastine: large, nearly equidimensional orthorhombic crystals from alcoholic

solution.

aggregates are formed is because the crystals are permitted to
grow too rapidly on the slide. This is usually the case in the
usual method of procedure in securing crystals, i.e., by adding
a drop of a solution to the slide, and then allowing it to evaporate
spontaneously, under ordinary conditions. If, on the other hand,
the rate of evaporation is lessened so that there is a slowing down
of the growth of the crystals, individuals may be obtained of

MICROSCOPIC TECHNIQUE AND REAGENTS. 771

almost any size desired. And it will be found that these isolated
crystals may be quite as easily prepared as the aggregates which
seem so characteristic to the average student. Special methods,
however, may be necessary to obtain such isolated crystals. For
instance, single crystals of menthol (Fig. 126) are obtained by

FIG. 424. Pipeline: monoclinic crystals, mostly on the clinopinacoid, showing the oblique
terminations, obtained from hot alcoholic solution.

means of sublimation rather than from solutions. Cumarin
crystals are easily obtained by controlling the temperature of the
melted mass, etc.

The interest in these crystalline substances is becoming greater
as foods and drugs and technical products are subject to stand-
ards of purity. Most of the crystalline constituents common to

'772 A TEXT-BOOK OF BOTANY.

plant products are usually said to be calcium oxalate. This sub-
stance is insoluble in water, alcohol, and acetic acid, soluble in
the mineral acids and occurs usually in definite crystals. These
crystals are rather easily studied in Iris, Quillaja, etc. (see page
186). They are found to crystallize either in the tetragonal or
monoclinic systems, sphenoids of the latter being present in
Belladonna (see pages 183-192).

Some substances occur in a crystalline form even upon the
commercial product, as vanillin upon vanilla pods and cumarin
upon tonka seeds; or crystals may be found in special cells, as
piperine (Fig. 424) in Piper album and Piper nigrum. In alco-
holic material, particularly of the Composite, characteristic sphere-
crystals are found, as in inula (see pages 150-154). Sometimes
similar sphero-crystals are observed upon soaking the drug of
commerce in water and then adding alcohol, as in Scilla. Again,
crystalline substances separate upon the addition of mineral acids,
as when nitric acid or sulphuric acid is added to sections of
Hydrastis (Fig. 95). Again, upon dissolving the product either
in water, as with catechu, or in solutions of chloral, as with
gambir, a crystalline residue remains. Finally, upon extracting
the dried plant with suitable solvents, as Prollius' solution, and
evaporating the solvent, characteristic crystals separate, as with
coca, hydrastis, nux-vomica, cinchona, cola, guarana, etc. ; or
distinct crystalline precipitates may be obtained upon the addition
of special reagents, as palladous chloride to solutions containing
cocaine hydrochloride (Fig. 97), or gold chloride to solutions
containing caffeine (Fig. 96) . Attention has already been directed
to the fact (pages 173-^176) that quite a number of plant principles
are capable of being sublimed.

For some time past, in the study of certain of the cryptogams,
as bacteria, yeasts, and fungi, there has been a disposition to rely
upon physiological rather than morphological characters, this
being due not only to the fact that these are more constant and
characteristic in these organisms, but also to- the fact that distinct
morphological characters are entirely wanting in some cases.
While the necessity for this additional study in the higher plants
is not so apparent on account of the presence of well-defined
morphological characters, still the value of physiological marks

MICROSCOPIC TECHNIQUE AND REAGENTS. 773

as one of the bases of classification is coming to be recognized.
The best illustration of this is to be found in the monograph
of the genus Eucalyptus by Baker and Smith,4 in which they
have utilized the chemical properties and physical characters of
the oils, coloring principles, tannins, etc., in establishing differ-
ences of affinities or species. There is a growing tendency on the
part of investigators to study micro-chemically some of the char-
acteristic plant constituents, as alkaloids, etc. As a rule, how-
ever, the descriptions are superficial and the identification is by
means of color reactions. No real scientific progress will be
made until the botanist employs the petrographical microscope
and is fairly well grounded in the principles of physical and
chemical crystallography. The work is by no means so simple
as in ordinary microscopic work, but when the principles governing
the optical study of crystals are mastered, the study will appeal to
botanists not only as a fertile field for research but also as a
subject of importance in both morphological and taxonomic work.

The study of microscopic crystals is accomplished by means
of the petrographical microscope. Brown (loc. cit.) has stated
succinctly the nature and use of this instrument :

" The necessity of studying small crystals, . . . has re-
sulted in the evolution of a form of microscope which is at once
a goniometer, a polariscope, and an instrument for measuring
optic axial angles — in short, for determining the physical crys-
tallographic constants of small crystals. . . . The polari-
scope portion of the petrographical microscope enables the ob-
server to determine the position and relative value of the elasticity
axes of crystals, to observe the position of the optic axes, and
to determine their inclination to each other and to the elasticity
axes. From these data the optical character of the crystal is
determined. These OPTICAL REACTIONS may be studied by this
instrument with as much ease, and in general with as much
accuracy, as with the larger and better graduated polariscope;
and the data thus obtained are quite as accurate in most cases
as those obtained by the use of the larger instruments. The.
use of the special eye-pieces arranged with artificial twins of
calcite or quartz enables the observer to determine the extinction

774 A TEXT-BOOK OF BOTANY.

angles of the crystals with as much accuracy as can be done with
any form of polariscope.

" From such observations made with the aid of this form of
microscope the following constants may be determined:

" ( i ) The plane angles of the crystals, in most cases the
interfacial angles, giving the data from which the axial ratios are
computed—in other words, the morphological constants of single
crystals.

" (2.) The relation of the composite crystals or twins to each
other, their angles, and the position of the twin plane, twin axis,
composition plane, and other constants of the twin crystals.

" (3) The pleochroism of the crystals, the character of the
colors of the light vibrating parallel to the elasticity axes in
the crystals. This is effected by the use of the single polarizing
prism below the stage. By analyzing this light with the micro-
spectroscope the differences of tint and color may be given
quantitative values in wave lengths.

" (4) The position and relative values of the light elasticity
axes in the crystals, upon which depend the angles of extinction
of the crystals, measured from certain crystallographic axes or
planes or edges. In uniaxial crystals (tetragonal and hexagonal
systems) there are two such elasticity axes — the ordinary ray des-
ignated as w, and the extraordinary ray, designated as e. Either
one of these may be the axis o*f greater or less elasticity ; and
according as the extraordinary ray is the axis of less elasticity
or of greater elasticity the crystal is called optically POSITIVE
or optically NEGATIVE. In biaxial crystals (orthorhombic, mono-
clinic and triclinic systems) there are three elasticity axes at
right angles to each other, and these are designated as fl, the
axis of greatest elasticity; J), the axis of mean elasticity; and
(, the axis of least elasticity.1

" (5) The position and angle of inclination of the optic axes
or lines of single refraction through the crystals. These always
lie in the plane of the elasticity axes & and t and the angles
between the optic axes are bisected by the axes & and C. Accord-
Elasticity in the optical sense is the reciprocal* of refractive index;
.hence a, b, t, are the axes of least, mean and greatest refractive index.

MICROSCOPIC TECHNIQUE AND REAGENTS. 775

ing as to whether t or a is the axis bisecting the acute angle, the
ACUTE BISECTRIX, Bxa, the crystal is called optically POSITIVE
or optically NEGATIVE. Thus if Bxa - t, the optical -character is
POSITIVE. The apparent angle between the optic axes is deter-
mined by means of an eye-piece micrometer in an observation of
the interference figure, looking along the acute bisectrix of the
optic axes, and this angle is designated as 2.E. The character
of the double refraction may be determined by this angle."

It is not possible in this work even to attempt to treat of the
principles underlying the study of physical crystallography. The
study is one requiring special laboratory instruction. Of the
excellent works which the student will find useful the following
may be mentioned :

P. GROTH : Physikalische Krystallographie, 4th Ed., 1905.

THEODOR LIEBISCH : Grundriss der Physikalischen Krystallographie, 1896.

HENRY A. MIERS: Mineralogy, 1902. In this work will be found several

excellent chapters dealing with the principles of the measurement of

crystals and the study of their optical properties.
ROSENBUSCH AND WuLFiNG : Mikroskopische Physiographic der Mineralen

und Gesteine.
P. GROTH : An Introduction to Chemical Crystallography. Translated by

Hugh Marshall, 1906.

In the Zeitschrift fiir Krystallographie will be found refer-
ences to the crystallographic studies which have been made upon
some of the important plant constituents, but as these studies
were mostly made upon relatively large crystals, which could be
measured and examined by means of the goniometer, these
observations must be interpreted and applied to crystals which
are formed upon microscopic slides.

A rather large number of substances have been examined and
only a few of the more important are included at this time.
While drawings might have been made to illustrate the form of
crystals and optical orientations, it was deemed advisable to use
some of the photo-micrographs made by the author. The four-
color plate (Figs. 99, 100) is introduced to show the chromatic
effects observed by using crossed nicols. The plate illustrates
salicin and cocaine hydrochloride and is a nearly exact reproduc-
tion of the effects obtained with the micro-polariscope, the electros

776 A TEXT-BOOK OF BOTANY.

having been made from Lumiere autochrome plates, using direct
sunlight.

The method of obtaining the crystals was rather simple. The
solvents used were distilled water, alcohol, ether, chloroform
and a mixture of chloroform and alcohol. To a weighed amount
of the substance was added a sufficient quantity of solvent to
give a saturated solution. A drop of this was added to a slide
which was covered either with a bell-jar or the cover of a Petri
dish. If the crystals formed too rapidly, giving rise to crystal
aggregates, more dilute solutions were made from the original
solution until single crystals were obtained therefrom. In some
instances, as with physostigmine salicylate, where the edges of
the crystal are likely to be re-dissolved, the slides were finally
dried in a desiccator over sulphuric acid. With caffeine gold
chloride, the best crystals were obtained when the solutions were
relatively weak. Again, it was found that after crystals were
mounted in balsam, as cocaine hydrochloride, caffeine gold chlo-i
ride, etc., the isolated crystals grew considerably in size at'
the expense of amorphous material. A rather unique instance
of growth of large crystals was with menthol when the slide con-
taining the silky aggregates was covered with another slide.
Finally it should be stated that some patience and experience are
necessary to obtain satisfactory crystals.

WORKS OF REFERENCE.

Principles of Microscopy. By A. E. Wright.

Das Mikroskop. By Leopold Dippel.

Anleitung zur Mikrochemischen Analyse. By H. Behrens.

Die Botanische Mikrotechnik. By A. Zimmermann.

Methods in Plant Histology. By Charles J. Chamberlain,

Elements of Drawing. By John Ruskin.

For Drawing of Crystals, consult " Crystallography and Practical Crystal

Measurement," by A. E. H. Tutton.
Physical Optics By Robert W. Wood.

INDEX.

Abelmoschus, 434
Abies, 119, 213, 434
Abnormal root structure,
319

stem structure, 344
Abortive, 391
Abrin, 198, 575
Abroma, 615
Abrotanum, 434
Abrus, 434. 575
Absinthe, 719
Absinthin, 719
Absinthium, 434, 719
Abuta, 539
Abutilon, 610, 611
Acacia, 434, 567, 569, 575
Acajou gum, 599
Acanthaceae, 694
Acanthus family, 694
Accumbent, 426
Acer, 434, 602
Aceraceae, 602
Acetaldehyde, 234
Achene, 410
Achillea, 172, 434, 720
Achilleine, 172
Achras, 659
Achyranthes, 528
Acid abietic, 237

acetic, 234

amido-succinamic, 168

amino-acetic, 192

antirrhinic, 691

arabic, 222

arachidic, 212

behenic, 212

benzoic, 234

capric, 212

caproic, 212

caprylic, 212

carthamic, 720

cerasic, 223

chaulmoogric, 214

chebulinic, 633

chromic, 756

cinnamic, 234, 572

formic, 234, 287

gallic, 599

gurjunic, 621

gynocardic, 623

hederic, 636

hydrocyanic, 198, 235

hypogaeic, 213

isovaleric, 234

japanic, 213

kinic, 655

Acid, lactic, zymase, 245

lauric, 212

lichen, 72

lignoceric, 212

linoleic, 213

lycopodic, 213

magenta, 182

methysticinic, 177

myristic, 212

oleic, 213

palmitic, 212

pectinic, 243

phosphomolybdic, 164

phosphoric, 214

picric, 165, 756

picric-sulphuric, as fixing
agent, 756

pipitzahoic, 723

protocatechuic, 204

rapic, 213

resinolic, 237

ricinoleic, 213

salicylic, 234

stearic, 212

succino-abietic, 237

sulphuric, in germination,
731

tiglic, 213

yellow A. T., 182
Aconite, 434, 533, 534
Aconitum, tubers of, 328
Acorn-cups, tannin in, 206
Acorus, 434, 479
Acre, 434
Acris, 434
Actaea, 434, 537
Actinomorphic, 393
Acubin, 696
Acuminate, 355, 434
Acuminatus-a-um, 434
Acute, 354

Acutifolius-a-um, 434
Adansonia, 612
Adder's tongue, 458
Adderwort, 438
Adhatoda, 696
Adhesion, 390
Adiantum, 88, 434
Adlumina, 550
Adnate, 381
Adnation, 390
Adonis, 434. 537
Advena, 434
Adventitious root, 301
^Ecidiospores, 69
/Ecidium, 69

A6gle. 434
Aerial root, 306
Aerobes, 252
^Esculin, 169, 602
^Esculis, 602

tannin in, 206
^Estivalis, 434
African ammoniac, 639
Afzelia, 575
Agar-agar, 34
Agaric, 63, 64, 456

surgeon's, 65
Agaricaceae, 59
Agaricus, 434

campestris, 59
protein in, 200

muscarius, 155
Agave, 434. 489

constituents of, 492

fiber, 269
Agavose, 155
Agglutins, 198
Aggregatae, 707
Aglykone, 169, 170
Agrimonia, 434
Agropyron, 434, 468
Agrostemma, 172, 426, 434
Ailanthus, 434, 586

family, 585
Air-bubbles, 752

method of detection, 752
Air plants, 480
Aizoaceae, 528
Ajowan oil, 643
Ajuga, 434

Akene (see Achene), 410
Albizzia. 575, 435
Albumins, 194, 195
Albus-a-um, 435
Alchemilla, 435
Alcoholase, 245
Alcohol, benzyl, 233

camphyl, 233

ceryl, 214

cinnamic, 233

ethyl, 233

melissyl, 214

methyl, 233
Aldehyde, 234

cinnamic, 544

salicylic, 564
Alder, 435, 510

buckthorn, 604
Aletris, 435, 480
Aleurites, 592

oil in, 213

777

INDEX.

Aleurone, grains, 193
Alfa, 472
Alfalfa, 577
Algae, 7, 435

blue-green, 8

characteristic, 16

classes, 17

economic uses of, 40

of Red Sea, 8

of Yellowstone Park, 8

polluting water, 8

used as food, 40

used in medicine, 40
Alga-fungi, 42
Alisma, 466
Alismaceae, 466
Alizarin, 179. 7O3

preparation of, 704
Alkaloids, 159

chemical classification,
1 66

effect of climate on, 165

families yielding, 165

from cultivated and wild
plants, 739

functions of, 172

microchemistry of, 160

origin of, 160

properties of, 163

reagents for, 163
Alkanet, 670
Alkanna, 670
Alkannin, 670
Allisin, 489
Allium, 435, 485, 489

vascular bundle of, 309
Allspice, 455

wild, 438
Almond, 435

emulsin, 243

oil in, 213
Alnus, 435. 5io

glandular hairs in, 230
Aloe, 435

species of, 487

wood, 628
Alpinia, 494. 651
Alsine, 435. 53 1
Alstonia, 435
Alteration in forms of plants,

332
Alternation of generation,

78, 86

Althaea, 435, 609, 6n
Alum root, 447, 556
Alyssum, 435
Amandin, 195
Amanita, 60-65
Amarantaceae, 528
Amaranth, 435
Amaranthus, 435, 528
Amarus-a-um, 435
Amaryllidaceae, 489
Amaryllis, 435, 492
Amaryllus family, 489

Amber, 119, 237

fossil, 119

seed, 6ll

Ambrosia, 435, 726
Ambrosiaceae, 712
Ambrosioides, 435
Amelanchier, 562
Aments, 508
American aloe, 434

copal. 574

kino, 569, 571

linden, 608

pennyroyal, 676

senna, 360

Americanus-a-um, 435
Amino-acid, 167
Ammanni, 435
Ammoniac, 639

African, 639

plant, 444
Ammoniacum, 435
Amomum, 435, 494
Amorpha, 435, 574
Amygdalin, 169, 170
Amygdalus. 435
Amylo-dextrin, 145
Amylo-pectinase, 242
Amylose, 144, 242
Amylum, 435
Amyris, 585
Anabasis, 527
Anacardiaceae, 595
Anacardium, 435, 596, 599
Anacyclus, 435 714
Anaerobes, 252
Anagallis, 436
Anagyris, 575
Analysis, micro, 776
Anamirta, 436, 539
Ananas, 436, 480
Anatomical differences in

leaves, 370
Anatomy, i
Anatropous, 379
Andira, 436
Andrcecium, 381
Andromedotoxin, 648
Andropogon, 436, 467, 472
Anemone, 359, 436, 535, 537
Anemonol, 537
Anemonon, 537
Anemophilous flowers, 399
Anethol, 234, 643
Anethum, 436, 643
Angelica, 436

American, 643

European, 643

purple stemmed, 643

wild, 643
Angiosperms, 119

classification of, 463

development of, 120

economic importance of,
128

flowers of, 375

Angostura, 436, 443, 585
Angustifolius-a-um, 436
Anhalonidine, 625
Anhalonine, 625
Anhalonium, 625
Aniline blue, as staining

agent, 757
Anime, 586
Anise, 436, 448, 639

Japanese star, 540

protein in, 200

star, 448
Anise-scented golden-rod,

722

Anisomeria, 528
Anisum, 436, 448, 639
Annatto, 621
Annual herbs, 330

rings, 343
Annular, 273
Annulus or ring, 61
Annuus-a-um, 436
Anogra, 436
Anona, 542
Anonaceae, 541
Anthelminticus-a-um, 436
Anthemis, 436, 713
Anther, 379

appendages of, 381
Antheridium, 5
Antherozoid, 5
Anthoceros, 83
Anthocyanin, 209, 210

origin of, 180
Anthophylli, 631
Anthotaxy, 393
Anthoxanthum, 436, 472
Anthracene, 170

derivatives, 179
Antidesma, 594
Antirrhinic acid, 691
Aparine, 436
Apeiba, 609
Apex of leaf, 354
Apiin, 169, 170
Apiol, 234, 643
Apiose, 169
Aplastic, 172
Apocarpous, 376
Apocynaceae, 574, 664
Apocynum, 386, 436, 664

fruit, 412

seed, 429
Apostasieae, 496
Apothecia, 73
Appendages of anther, 381
Apple, 457, 562

cedar, 115

earth, 440

may, 538

protein in, 199

rose, 632

rust, 115

star, 441, 659

sugar in, 156

INDEX.

779

Apricot, 562, 620

oil in, 213

protein in, 199

sugar in, 156
Aquaticus-a-um, 436
Aquifoliaceae, 600
Aquifolium, 436
Aquilaria, 628
Aquilegia, 536
Arabicus-a-um, 436
Arabin, 222
Araceae, 475, 478
Arachis, 401, 576
Arachnoidiscus, 35
Aragallus, 574
Arales, 475
Aralia, 436, 636, 637
Araliaceae, 636
Araroba, 436

tree, 462
Arbor, 460

vitae, 118
Arbutin, 169, 170, 174,

176

Arbutus, trailing, 644, 649
Archegoniates, 75
Archegonium, 75
Archesporium, 79, 124
Archichlamydeae, 504
Arctium, 436, 715, 717
Arctostaphylos, 174, 436,

644. 651
Areca, 436, 473
Arecaidine, 474
Arecaine, 474
Arecoline, 473
Arethusa, 502
Argania, 659 '
Argemone, 436, 547
Arginin, 253
Argithamnia, 436, 594
Arillode, 427
Arillus, 427

Arisaema, 436, 477. 480
Aristolochia, 436, 519, 521
Aristolochiales, 519
Aristotelia, 609
Arnica, 437, 715

pollen of, 404
Arnotta, 621
Aromaticus-a-um, 437
Aros, 437
Arrow-head, 466
Arrow-poison, 516, 575. 593,

633, 662
Arrow root, 462

Maranta, 496

soft-leaved, 706

starch, 496
Arrow wood, 705

maple-leaved, 705
soft-leaved, 706
Artemisia, 437, 719

hairs of, 285
Artemisiaefolius-a-um, 437

Arthrospore, 12
Artichoke, ferment in, 244

globe, 726

Jerusalem, 725
Artificial coloring of flowers,

182

Artocarpus, 437, 516
Arum, 437, 478
Arundinaceus-a-um, 437
Arvensis-e, 437
Asafoetida, 445, 639
Asagraea, 437
Asarone, 520
Asarum, 365, 437, 520
Asci, 47

Asclepiadaceae, 574, 668
Asclepias, 437. 667, 668
Ascomycetes, 47
Ascophyllum, 30
Ascus, 47
Asexual generation, 298

spore, 298
Ash, 446

mountain, 562

prickly, 462

white, 661

wild mountain, 454
Asimina, 437, 541
Asparagine, 167, 253, 725
Asparagus, 437, 485, 489

protein in, 199

sugar in, 156
Aspen, 456
Aspergillus, 49
. emulsin, 243
Asperula, 437
Aspidium, 437
Aspidosperma, 437, 667
Asplenium, 437
Assimilation root, 306

shoot, 299
Aster, 712, 726
Astragalus, 437, 569, 574

gum in, 218

Athamanticus-a-um, 437
Atmospheric nitrogen, fixa-
tion of, 307
Atriplex, 437. 52?
Atropa, 437, 683, 684

fruit, 412
Atropous, 379
Atropurpureus-a-um, 437
Attar of rose, 564
Aucuba, 643
Aucubin, 643
Aurantiamarin, 585
Aurantium, 437
Auric chloride, 165
Australis-e, 437
Autumnalis-e, 437
Auxochrome, 179
Auxospores, 37
Avena, 437, 467

structure of, 423
Avenalin, 195

Avens, 446

Avocado, 455

Ax-seed, 442

Azalea, glandular hairs in,

230
purple, 646

Baccaurea, 594
Baccharis, 437, 723
Baccifer-a-um, 437
Bacillus, 14

hay, 13

subtilis, 13

typhosus, destroyer of,

655
Bacteria, 12

aerobic, 12

anaerobic, 12

classes of, 13

sulphur, 14
Bacterium, 14
Balanophora, 519
Balanophoraceae, 519
Balata, gum, 659
Balatium, 241
Ballota, 437
Balm, 452

of Gilead, 508

sweet, 679
Balsam, 225

Canada, as mounting me-
dium, 757

gurjun. 621

.Maiacaibo, 572

mounts, 763

of fir, 118

of the gardens, 604

of Tolu, 572

Oregon, 119

poplar, 508

Sindor, 621

tree, 461

Balsamifer-a-um, 438
Balsaminaceas, 604
Balsams, 236
Balsamum, 438
Bambusa, 466
Banana, 496

protein in, 199

sugar in, 156
Baneberry, 434, 537
Banskia, 518
Baobab, 612

Baptisia, 438, 567, 573. 575
Baptisin, 169
Barbaloin, 169
Barbarea, 438
Barberry, 438

family, 537
Barbiera, 575
Barium salts, 575
Bark, 317
Barley, 448

lecithin in, 214

protein in, 199

78o

INDEX.

Barley, starch in, 148

sugar in, 156
Barosma, 438, 583
Barringtonia, 629
Base of leaf, 356
Basidiomycetes, 56
Basil, sweet, 679
Bassia, 659
Bassorin, 223
Basswood, 609
Bastard cedar, 580

santal, 580
Bauhinia, 575
Bayberry, 212, 508
Bay oil, 632

rum, 632

Beale's carmine solution, 760
Bean, 576

buck, 452

garden, 576

Indian, 440

Japanese soy, 576

kidney, 455

lima, 199

pichury, 453

protein in, 199

Sacred, 453

sea, 575

Bearberry, 436, 461, 651
Beard grass, 436
Bearwort, 452
Beauty, meadow, 634
Bebeeru, 453, 546
Bedstraw, 446, 697, 704

yellow, 704
Beeberine, 546
Beech, 445, 510

American, 512

drops, 696
false, 644

nut, protein in, 199

purple, 178

red, 512

Beer manufacture, 515
Beet, 438, 527

garden, protein in, 199
sugar in, 156

sugar, 527

proteins in, 199
sugar in, 156
Beggiatoa, 14
Begonia, 624

hairs in, 282
Begoniaceae, 624
Belladonna, 438, 683, 740

hairs of, 284

lily, 435

root, cross section of, 318
Bell-flower family, 710
Bellwort, 485
Benedictus-a-um, 438
Bengal quince, 434
Benne oil, 691
Benzaldehyde, 234
Benzoinum, 438, 660

Benzo-quinhydrone, 179
Benzoquinone, 179
Benz-pyrrol, 180
Berberidaceas, 537
Berberine, 162, 180
Berberis, 438, 537
Bergamia, 584
Bergamot, 679

oil, 584

wild, 679
Berry, 410

partridge, 452
Bertholletia, 629
Beta, 438, 527

stomata on leaves, 367
Betel, 508

leaves, 506

nut, 436, 473
palm, 476
Betonica, 438
Betony, 438
Betula, 438, 510

cross-section of wood, 346
Betulaceae, 510
Betulase, 243
Betulinus-a-um, 438
Bezoars, vegetable, 577
Bhang, 516
Bicollateral mestome

strands, 341
Bicuculla, 550, 551
Bidens, 438
Biennial herb, 330
Biennis-e, 438
Bifacial leaves, 349, 366
Biflorus-a-um, 438
Bigardia oil, 584
Bignonia, 438
Bignoniaceae, 691
Bilabiate, 386
Bilberry, 654, 655
Bind weed, 442
Birch, 438, 510

family, 510

white, cross-section of

wood, 346
Bird food, 696
Bird-lime, 518
Birthroot, 461
Birthwort, 436

family, 519
Bisectrix, 775
Bishop's cap, 452
Bismarck brown, as staining

agent, 757
Bistorta, 438, 527
Bitter sweet, 444, 684
Bixa, 621 4
Bixaceae, 621
Bixin, 622
Blackberry, 458

bush, 563

low, 563

sand, 563

sugar in, 156

Black catechu, 569

haw, 462, 704

hellebore, 537
Bladder-wrack, 28
Blade, 348
Blakea, 634
Blazing star, 449
Blights, 44
Blinding tree, 592
Blood orange, 584

root, 458, 547

Blueberry, cultivation of.
656

dwarf, 653

early sweet, 653

high bush, 655

low, 654

low-bush, 655
Blue flag, larger, 492

indigo, 574
Bluets, 448, 697
Bocconia, 550
Boehmeria, 438, 517

fibers in, 269
Bcerhavia, 528

hairs in, 282
Bogbean, 665
Bog plants, 480
Bogs, sphagnum, 84
Bohmer's hasmatoxylin so-
lution, 760
Boletus, 61
Bombaceae, 554, 612
Bombax, 554, 612
Bondicine, 576
Boneset, 712

false, 449

Borage family, 670
Border, 386
Bork, 293

Borneo camphor, 620
Borneol, 233, 544, 676
Borraginaceae, 670
Boswellia, 587

hairs in, 282
Botrychium, 365, 438
Bottle, reagent, for sterile

solutions, 757
Bougainvillea, 528
Bouncing bet, 530, 531
Bower, Virgin's, 441
Box tree family, 594
Boxwood, 439
Brabeium, 518
Brachycerus-a-um, 438
Bracts, 388, 393, 402
Bramble, 458
Branches, lateral, 312
Brandy, 607
Brasiliensis-e, 438
Brassica, 438, 552, 553
Brauneria, 438, 723, 724

oil canals in, 224

phytomelane in, 260
Brazilian copal, 574

INDEX.

781

Brazilin, 179, 180

Bursine, 554

Brazil-nut, 629

Butcher's blocks, 560

aleurone grains of, 194

Butneria, 439

Breadfruit, 437, 516

Butter, cacao, 612

Bread, St. John's 576

shea, 659

Breadstone, 39

vegetable, 659

Breathing root, 306

Butter-and-eggs, 691

Bridelia, 593

Buttercup, 457, 537

Brier, cat, 459

Butter-fly weed, 667 ^

green, 459

Butternut, 509

Bromeliaceae, 480

Buttonbush, 440, 703, 704

Bromelin, 244

Buttons, 473

Broom, 443

mescal, 625

green, 569

Button-snakeroot, 722

Scotch, 569

Buttonwood, 559

weed, 458

Butyrospermum, 659

Broom-rape family, 696

Buxaceae, 594

Brosimum, 516

Buxine, 594

Brucamarine, 586

Buxus, 439, 546. 594

Brucea, 586

Bruguiera, 631

Cabbage. 553

Brush, 472

Cacao, 148, 211, 439, 460,

Bryonia, 438, 709

612

sieve in, 276

butter, 612

tendril of, 323

protein in, 199

Bryonidin, 709

red, 612

Bryonin, 709

seeds, 612

red, 709

starch in, 148

white, 709

sugar in, 156

Bryophytes, 76

tree, 612

economic uses of, 84

Cactaceae, 625

Bubbles, air, 752

Cactus, 439, 621, 625

Buchania, 599

coach- whip, 621

Buchu, 152, 438, 583

family, 625

Buckbean, 665

Cadinene, 233, 589, 642

Buckeye family, 602

Caducous, 388

Buckthorn, 445, 457

Cassalpinia, 439, 576

family, 604

coriaria, tannin in, 206

Buckwheat, 445, 526, 527

Caesalpinioideas, 567

family, 520

Caffeine, 162, 176, 600, 618,

flowers, 400

700

protein in, 199

Cajuputi, 439. 452

sugar in, 156

Calabar bean, 455

Bud, apical, 321

Calamint, 441

axillary, 321

Calamites, 100

scale, 1 20

Calamus, 439, 474, 479

scaly, 321

Calcarate, 388

terminal, 321

Calcium carbonate, 200

Buds, 321

oxalate, 183

Buffalo berry, 628

phosphate, 186

Bugbane, 441

Calendula, 387, 439, 718

Bugle weed, 434, 451

hairs in, 288

Bulb, 327

pollen of, 405

Bulbils, 327

Calisaya, 439

Bulblets, 327

Calla, 439, 479

Bunt, 461

Calla-lily, 478

Bur, 510

Callitris, 119

Burdock, 436, 449, 715, 717

Calluna, 439

Burning bush, 600

Callus, 277

Bur-reed, 464

Calophyllum, 439, 618, 619

family, 463

inophyllum, 212

Bursa, 438

Caltha, 439

pastoris, 439

Caltrop family, 581

Bursera, 587

Calumba, 439, 539

Burseraceae, 586

American, 445

Calyptrogen, 254
Calyx, 402

duration of, 388
Cambium, 314

intrafascicular, 341

ring, 341
Cambogia, 439
Camelina, 439
Campanulaceae, 708, 710
Campanulatae, 708
Campanulate, 388
Campechianus-a-um, 439
Campestris-e, 439
Camphene, 676
Camphor, 439, 544, 546, 620

Borneo, 620

culture, 746

Japanese, 234

Laurus, 234

tree, 545
Campion, 451
Camptosorus, 439
Campylotropous, 379
Canada fleabane, 713

moonseed, 539
Canadensis-e, 439
Canaigre, 527
Canango, 542
Canarium, 586
Cancer root, 695, 696
Cane, 439, 445
Cane-sugar, 155, 156
Canella, 622

bark, 622

substitute, 622
Canellaceae, 622
Canna, 496
Cannabinus-a-um, 439
Cannabis, 439, 513

American, 741, 742, 744

fiber, 269

hairs of, 284
Cannaceae, 496
Cantaloupe, 710

sugar in, 156
Cantharellus, 58
Caoutchouc, 439, 513, 516,
592

threads, 240
Cape jasmine, 704
Caper, 579

spurge, 591

wild, 591

Capillaceus-a-um, 439
Capillus-Veneris, 439
Capitulum, 711
Caprifoliaceae, 704
Capsella, 438, 439, 554

ferment in, 244
Capsicum, 439, 687

protein in, 200
Capsule, 411
Caraipa, 618
Caramel, synthetic, 159
Carapa oil, 589

INDEX.

Caraway, 440, 639

protein in, 200
Carbamases, 244
Carbohydrates, origin of, 157

photosynthetic, 157
Carbon dioxide assimilation,

299, 350

Carboniferous age, 99
Carbon-like substance, 258
Cardamom, 410, 435, 439,
444, 494

protein in, 200

starch in, 148
Cardinal flower, 710
Cardol, 596
Carduus, 451
Carex, 439, 47 1, 472
Careya, 629
Carica, 440, 542, 624

ferment in, 244
Caricaceas, 624
Carices, 472
Carnation, 443, 531
Carnauba-palm, 214, 474
Carnauba-wax, 474
Carnivorous plants, 361
Caroba, 691
Carobine, 691
Carobone, 691
Carolianus-a-um, 440
Carolina pink, 661
Carolinensis, 440
Carota, 440
Carotin, 493, 636
Carpaine, 624
Carpel, 120, 374~3?6
Carpinus, 440, 510
Carpophore, 417
Carposid, 624
Carragheen, 31
Carrot, 440, 443

family, 636

protein in, 199

starch in, 148

sugar in, 156
Carthamic acid, 720
Carthamin, 720
Carthamus, 387, 719

pollen of, 405
Carum, 440, 639, 643
Caruncle, 427
Carvacrol, 234, 679
Carvi, 440
Carvone, 234
Carya, 333

cross-section of wood, 346
Caryophyllaceae, 531
Caryophyllene, 571
Caryophyllus, 440, 632
Caryopsis, 417, 466
Caryota, 476
Cascara, 440, 604
Cascarilla, 440, 592
Cascarillin, 592
Casearia, 623

Cashew, 435.

nut, 458, 596
Cassia, 360, 440, 567, 575

purging, 567

species of, 567
Cassine, 600
Castanea, 440

cross-section of wood, 346

species of, 512
Castilloa, 241, 516
Castinin, 195
Castor bean, 457

aleurone grains in, 194

plant, 443, 591
Catabolism, 252
Catalases, 245
Catalpa, 440, 691
Catalpin, 691
Cataria, 440
Catawba grape, 606
Cat brier, 485
Catechin, 180
Catechu, 440

black, 569
Catha, 600
Cathartocarpus, 440
Cathine, 600
Catkin, 394
Cat mint, 680
Catnip, 440, 453, 680, 681
Cat-tail family, 463
Cauliflower, protein in, 199

sugar in, 156
Caulophylline, 538
Caulophyllum, 440, 537
Cavanillesia, 612
Cay-Cay butter, 586
Ceanothus, 440, 604
Cecidien, 334
Cedar, 460

apples, 115

bastard, 581

prickly, 454

red, 115, 118

uses of, 115-117

white, 118

wood oil, 589
Cedrela, 589
Cedron, 440, 459

seed, 440
Cedronin, 586
Cedrus, 118

Celandine, 441, 548. 551
Celastraceae, 600
Celastrine, 600
Celastrus, 440, 600
Celery, protein in, 199
Celloidin, 749
Cells, 2

antipodal, 124

apical, 254

conducting, 272

contents, examination of,
246

Cells, contents reaction with
microchemical reagents,
759

cork, 290,

division, 3

epidermal, 277

forms of, 262

guard, 279

helping, 124

inclusion, 207

kinds of, 297

laticiferous, 239

protecting, 277

sclerenchyma, 266

sclerotic, 267

secretory, 226

stereomatic, 268

stone, 267

tapetal, 121, 404
Cellulases, 244
Cellulose, 256

walls, protective, 257
Cell- wall, reaction with mi-
crochemical reagents,
759

stratification in, 258
striation in, 259
Celosia, 528
Centaurea, 440
Centifolius-a-um, 440
Centrifugal, development 262
Centripetal, development.

262

Centrospermae, 527
Centrospheres, 135
Century plant, 489
Cephaelis, 440, 699
Cephalanthin, 704
Cephalanthus, 440, 703, 704
Cephalaria, 708
Ceramium, 40
Cerasin, 223
Ceratonia, 440, 576
Cerealis-e, 440
Cereus, 625, 627

night-blooming, 625
Cetraria, 73, 440
Cevadilla, 458
Chakazzi copal, 574
Chamaelirium, 440, 491
Chamomile, German, 715

Roman, 713

wild, 452
Chamomilla, 440
Champagne, 607
Chanterelle, 58
Characeae, 26
Charcoal, 508, 509
Charlock, 553
Chartreuse, 679
Chavicol, 632
Chebulinic acid, 633
Chekan, Eugenia, 441, 63*
Chelerythrine, 550
Chelidonine, 550

INDEX.

783

Cheliodonium, 441, 548, 550,

551

Chelidoxanthin, 550
Chelone, 441, 691
Chemical stimuli, 248
Chenopodiaceae, 527
Chenopodiales, 527 ,
Chenopodium, 441, 527

hairs in, 282
Cherry, 456

bark of, 294

choke, 561

cross-section of wood, 346

protein in, 199

sugar in, 156

wild, 561

black, 560
Chestnut, 511

American, 512

bark disease, 54

cross-section of wood,
346

horse, 206, 602

oak, tannin in, 206

protein in, 199

Spanish, 512

starch in, 148

sugar in, 156

tree, 440

wild, 518
Chests, tea, 625
Chewing gum, 659
Chew-stick, 447
Chickweed, 435
Chicory, 441, 716, 725

culture, 747

Chimaphila, 441, 455, 644
Chinese galls, 597

potatoes, 492

rice paper, 636

tallow tree, 594
Chinquapin, 512

starch in, 148
Chionanthin, 661
Chionanthus, 441, 661
Chirata, 441, 664
Chirayita, 441, 664
Chiretta, 460, 664
Chives, 485
Chloral, crystals, 762
Chloranthy, 391
Chlorenchyma, 366
Chlorococcum, 72
Chlorophora, 516
Chlorophycese, T7, 20
Chlorophyll, 138, 158
Chloroplastids, 137
Chloroplasts, 137
Chlorosis, 391
Chlor-zinc-iodide solution,

760

Choke cherry, 561
Chondrodendron, 441, 539
Chondrus, 31, 441
Choripetalae, 504

Choripetalous, 383
Chorisepalous, 383
Chorisia, 612
Chorisis, 390
Christmas holly, 600
Chromatin, 136
Chromatophore, 136

fixed oils in, 210
Chromene, 180
Chromic a*cid, 756
Chromogen, 179
Chromophores, 179
Chromoplastids, 137, 138

occurrence of, 181
Chromosomes, 136
Chrozophora, 593
Chrysanthemum, 441, 714,

718, 724, 726
Chrysarobinum, 441
Chrysophyllum, 441, 659
Chrysosplenium, 441, 556
Chymases, 244
Cicely, sweet, 643
Cichoriaceae, 711
Cichorium, 441, 716, 725
Cicuta, 441, 575, 642
Cigar boxes, 117, 589
Cimicifuga, 441, 532, 533
Cinchona, 441, 697

cultivated, 546, 690, 698

plantation, 698

species of, 699

substitute, 606, 620
Cineol containing oil, 544
Cinereus-a-um, 441
Cinnamic acid, 572

aldehyde, 544
Cinnamodendron, 622
Cinnamomum, 441, 543, 544,

545
Cinnamon cultivation, 545

cutting, 545

oil, 544

starch in, 148
Cinquefoil, 456
Circaea, 441, 634
Circinate, 364
Circumcissile, 413
Circumnutation, 360
Cirrhiferous, 357
Cissampelos, 441
Cistus, hairs in, 282
Citral, 233, 234. 564. 583
Citron, 441, 584
Citronellol, 564, 579
Citrullus, 441, 708, 710
Citrus, 441, 583. 584
Cladonia, 72, 74
Claptonia, 531
Claret, 607
Clavatus-a-um, 441
Clava-Herculis, 441
Clavaria, 58
Clavariaceae, 59
Claviceps, 441

Claviceps purpurea, 52

Claw, 385

Clearing agents, 755, 756

Cleavers, 446

Cleaverwort, 436

Cleft, 356

Clematis, 441, 537

cork in, 293
Climbers, 324

root, 324
Clinopodium, 441
Clitoria, 575
Clotbur, 462
Clove, 440, 441, 632

protein in, 200

starch in, 148

tree, 445
Clover, 567, 576

prairie, 449

sweet, 452
Club-like, 441
Clusia, 619, 620
Cnicin, 723
Cnicus, 441, 723
Coach-whip cactus, 621
Coal age, 99

deposits, 119
Coalescence, 390
Coca, 442, 580

family, 580

seedling, 745
Cocaine, 163, 170, 581
Cocci, 13
Coccos oil, 623
Cocculus, 442, 539
Coccus, 442, 516, 531, 606,
621, 627

lacca, 238

Cochineal insect, 627
Cochlearia, 442, 553
Cochlospermum, 223, 622
Cocillana, 516
Cocklebur, 462
Cock's-comb, 528
Cocoa (see Cacao)

Brazilian, 603
Cocoa-nut, 212, 474

palm, 474
double, 427
fruit, 413

protein in, 199
Cocos, 474. 476

fruit, 413

Codeine crystals, 767
Coffea, 442, 700
Coffee, 442, 700

aroma, 700

caffeine in, 162

cultivation, 700

Kentucky, 447

picking, 702

protein in, 199

roasting, 700

substitutes, 6n, 716

sugar in, 156

INDEX.

Coffee tree, 575, 701

wild, 632, 707
Coffeol, 700
Cohesion, 390
Cohosh, 434

black, 532

blue, 440, 537
Cola, 614, 615

caffeine in, 162

family, 612
Colchicum, 442, 485
Cold frames, 731
Colic-root, 435, 485
Coliguaya, 593
Collateral mestome strands,

Collenchyma, 265
Colletin, 606
Collinsonia, 442
Colloidal, 140
Colocynth, 708

fruit, 410, 424

seed, 424
Colocynthis, 442
Color in autumn leaves, 178

in lichens, 72

principles, chemistry, 179

substances, cell-sap, 176,
181

substances, distribution of,

181
Coloring of flowers, artificial,

182
Colors, cell-sap, 176

function of, 181
Coltsfoot, 387, 445, 461, 723
Colubrina, 606
Columbine, wild, 536
Columbo, 539
Combretaceag, 633
Combretum, 633

hairs in, 282
Comfrey, 460, 671
Commelina, 442, 480
Commelinaceae, 480
Commiphora, 442, 586
Common mossy stonecrop,

556

Communis-e, 442
Compass plant, 723
Complete flower, 298
Compositae, 711, 712

flowers of, 387

hairs in, 288
Compound leaves, 356
Comptonia, 509
Concentric mestome strands,

342

Conduplicate, 364
Condurango, 668
Cones, 375
Confluent, 381
Conglutin, 195
Conidia, 41
Conifera-um, 442

Coniferse, uses of, 117
Coniferin, 169, 170, 171, 489
Conium, 442, 638, 640
Conjugatae, 17
Conjunctive tissue, 313
Connate-perfoliate, 356
Connective, 122, 381
Conopholis, 695, 696
Consolodin, 673
Contortae, 660
Contraction of roots, 319
Contrayerva, 444
Convallamarin, 170, 442,

486

Convallaria, 487
Convolute, 364
Convolvulaceae, 668
Convolvulus, 442, 669
Copaiba, 442, 571, 574

substitute, 621
Copal, American, 574

Brazilian, 574

Chakazzi, 574

East Indian, 587

Inhambane, 574

resins, 574

Sierra Leone, 574

Zanzibar, 574
Copalchi, 592
Copalchin, 592
Copernicia, 474

cerifera, 214
Copper acetate solution, 761

treatment of water, 8
Coptis, 442
Coral root, 442
Corallorhiza, 442
Corchorus, 269, 609
Cordifolius-a-um, 442
Coriamyrtin, 595
Coriander, 442

protein in, 200
Coriandrum, 442, 637
Coriaraceae, 594
Coriaria, 594
Coriarious-a-um, 442
Cork cells, 290

development, 293
Corm, 329. 477
Corn, 467

Black Mexican, 178

cockle, 434, 446
seed, 426

Indian, 462
root-tip, 300

oil in, 213

protein in, 199

silk, 178

starch in, 148

sugar in, 156
Cornaceae, 643
Cornel, 442
Cornin, 643
Cornus, 442, 388, 643
Corolla, 382, 402

Corona, 623
Coronilla, 442, 575
Cortex, 310

secondary, 313
Corydaline, 551
Corydalis, 209, 551
Corylus, 442, 510
Corymb, 394
Corymbine, 702
Corynine, 702
Cotoneaster, 562
Cotton, 447

fiber, 269

protein in, 199

Sea Island, 610

seed, oil in, 213

oil, 611
Cotula, 442
Cotyledon, 299, 426
Couch-grass, 468
Coumarin, 472

in polypodium, 96
Couroupita, 629
Corillea, 581
Cowhage, 452, 576
Cranberry, 656

American, 655

European, 656

fruit, 417

small, 655

tree, 704
Cranesbill, 446
Crassulacea?, 556
Cratsegus, 442, 565
Crateriform, 388
Cratoxylum, 619
Crawley root, 453
Cream nut, 630
Crea.m-of-tartar tree, 612
Crecopia, 516
Cremocarp, 417, 636
Crenate, 356
Crenulatus-a-um, 442
Creosote, 512

bush, 580
Cress, Indian, 579
Cretian origanum, 679
Crinum, 492
Crispus-a-um, 442
Croceine M. O. O., 182
Crocin, 493, 704
Crocus, 442, 493, 704

pollen of, 404. 405

stigma of, 405
Crops, harvesting of, 738
Cross-pollination, 560
Cross-section, 749
Crotalaria, 442, 575
Crotin, 198
Croton, 443, 591-593

oil in, 213
Crowfoot, 457, 532
Crown-galls, 335
Crucifer-a-um, 443
Crucifers, 551, 574

INDEX.

785

Cruciger-a-utn, 443

Curare poison, 539

Cryptogams, 5

Curarine, 662

vascular, 86

Curatella, 615

Crystal, 769

Curcas, oil in, 213

biaxial, 774

Curcin, 198

clusters, 185

Curcuma, 494

codeine, 767

protein in, 200

columnar, 183

Curcumin, 496

fibers. 187

Currant, 457, 558

hexagonal, 774

Buffalo, 558

h'ydrastine, 77O

fetid, 558

membrane, 189

protein in, 199

micro, 187

sugar in, 156

microtechnic, 776

Cuscuta, 670

monoclinic, 183, 184, 774

Cuscutin, 670

of fixed oils, 211

Cusparia, 443, 585

of reagents, 762

Cusso, 443, 447, 565

orthorhombic, 183, 774

Custard apple, 543

piperine, 771

family, 541

sand, 188

Cutin, 277

solitary, 183

Cutose, 257

sphere, 192

Cyanol, P. P., 182

strychnine crystals, 769

Cyanophyceae, 8

tetragonal, 183, 774

glycogen in, 154

triclinic, 774

Cyanus, 443

uniaxial, 774

Cycads, in

Crystalline wax, 216

Cyclamen, 656

Crystallographic method of

hairs in, 282

examination, 767

Cydonia, 560

Crystalloidal, 140

Cylindric leaves, 349

Crystalloids, 193, 199

Cyme, 395

Cubeb, 443, 504

dibrachious, 395

substitute, 541

helicoid, 395

Cubebin, crystals, 768

rrionobrachious, 395

Cuckoo-pint, 437

Cymene, 643

Cucumber, 710

Cyminum, 443

protein in, 199

Cynara, 726

squirting, 444, 709

Cynips, 511

sugar in, 156

Cynoglossine, 6?3

tree, 540

Cynoglossum, 443, 673

sour, 612

Cynomorium, 519

Cucumis, 443, 710

Cyperaceae, 472

Cucurbita, 443, 709

Cyperus, 443, 472, 473

Cucurbitaceae, 708

Cypripedium, 443, 496, 498,

Cudbear, 74

501

Cudrania, 516

Cystoliths, 200

Cud weed, 446

Cystopus, 44

Cultivated and wild plants,

Cystotyles, 201

value of, 739

Cytases, 244

Cultivation of medicinal

Cytisine, 575

plants, 727

Cytisus, 443, 569

progress in, 744

Cytology, 13^*^** -^

Culver's root, 450, 689

Cytoplasm, 2, 135

Cumarin, 173

Cumin, 443, 643

Daisy, 712

oil, 643

fleabane, 713

Cuminum, 443, 643

white, 718, 724

Cunila, 443, 681

Damascenus-a-um, 443

Cup or bur, 510

Damiana, 623

Cupana, 443

Damianin, 623

Cuphea, 628

Dammar, black, 587

Cupule, 420

Dandelion, 460, 712

Curanga, 691

hairs in, 288

Curanjiin, 691

Daphne, 443, 627

Curare, 662

Daphnin, 170

D-arabinose, 169

Dark field illumination, 765

Date palm, 208, 473
endosperm in, 265

Dates, 475

Datisca, 625

Datiscaceae, 624

Datiscin, 169, 625

Datura, 443, 682, 684
ferment in, 244

Daucus, 443

Day-flower, 442, 480

Deadly nightshade, 684

Decandrus-a-um, 443

Deciduous, 388

Definite inflorescence, 394

Dehiscence, 411

Dehydrating agent, 755, 756

Delafield's haematoxylin so-
lution, 760

Delphinium, 443, 535, 574

Dentate, 356

Dentatus-a-um, 443

Dermatogen, 253

Derris, 575

Descent of plants, 133

Desmids, 17

Desmodium, 361, 443

Development, arrested, 391
of stomata, 368

Devil's apron, 30

Devonian age, 99

Dewberry, Northern, 563

Dextrin, 147

Dextro-glucose, 155

Dextrose, 155, 563

Diandrous, 381

Dianthus, 443
species of, 531

Diaporthe parasitica, 54

Diastase, 242

Diatomaceous Earth, 38

Diatoms, 35

Dibrachious (cyme), 395

Dicentra, 443, 551

Dicotyledonous stem struc-
ture, 339

Dicotyledons, 120, 501

Dictamus, 225, 443

Dicypellium, 544, 546

Didymus-a-um, 443

Didynamous, 381

Diervilla, 443, ?o?

Digitalin, 169, 170

Digitalis, 443, 690
hairs of, 284, 285
section of leaf, 372
seedlings, 743

Digitalose, 169

Digitonin, 169

Digitoxin, 169

Dill, 436
garden, 643
oil, 643
protein in, 200

786

INDEX.

Dillenia, 615
Dilleniaceae, 615
Dimorphic flowers, 399
Dioicus-a-um, 444
Dionaea, 362, 554
Dioscorea, 444, 492

stem of, 322
Dioscoreaceae, 492
Diosphenol, 582
Diospyros, 444, 659

hairs in, 282
Dipentene, 722
Diphyllus-a-um, 444
Diplococci, 14
Dipsacaceae, 707
Dipsacus, 444, 708
Dipterocarpaceas, 620
Dipterocarpus, 620
Dirca, 444, 627
Disaccharose, 154
Discaria, 606
Discoid head, 711
Disk-flower, 711
Dissepiment, 411, 378

false, 378
Dissotis, 634
Distichous, 363
Dita, 435

Ditch stonecrop, 454, 556
Dittany, 443

American, 682
Divergence, 363
Divided, 356
Divi-divi, tannin in, 206
Divining rod, 558
Division, internal, 5
Doassansia, 67
Dock, curled, 523

sorrel, 458
Dodder, 670
Dogbane, 436

family, 664

spreading, 664
Dog's-tooth violet, 485
Dogwood, 442

family, 643

flowering, 643

Jamaica, 448, 575 .
.Domesticus-a-um, 444
Domingensis-e, 444
Doona, 621
Dorema, 444, 639
Dorsal pneumatic tissue, 366

suture, 377
Dorsiventral flowers, 393

leaves, 349, 366
Dorstenia, 444
Double flowers, 714

staining, 762
Douglas fir, 114

spruce, 119
Dracaeno, 489
Dracontomelum, 599
Dragon's blood, 474, 488
Dragon tree, 489

Drimys, 540
Drosera, 361, 444, 554
Droseraceae, 554
Drugs, curing of, 738

drying of, 737, 738

physiological testing of,
248

selection of, 737
Drupe, 418, 426
Driizenzotten, 222
Dryobalanops, 620
Dryopteris, 87, 90, 92, 444

hairs of, 284

Dry yeast, lecithin in, 214
Duckweed, 450

family, 478

Ducts (see Tracheae), 273
Dulcamara, 444, 684
Dulce, Irish, 34
Dulcis-e, 444
Dulcitol, 156
Duration of calyx and

corolla, 388
Dutch clover, 472
Dutchman's breeches, 550
Dwarf branch, 374
Dye, leather, 633
Dyer's broom, 574
Dyes, aniline, as staining
agents, 75?

non-aniline, as staining

agents, 757

Dynamic centers of cell, 140
Dysentericus-a-um, 444
Dzaini, 562

Early sweet blueberry, 653
Eau D'Ange, 632

de Creole, 620
Ebenaceae, 444, 659
Ebenales, 658
Ebony, 444, 659

black, 659

family, 659

green, 659

red, 659

striped, 659

white, 659
Ecballium, 444, 709
Echinacea, 723

oil canals in, 224

phytomelane in, 260
Echinate, 354
Echinocarpus, 607
Ecology, i
Edestin, 195
Eelgrass, 466
Egg apparatus, 298

cell, 124, 298

plant, 688
Elseagnaceae, 628
Elaeagnus, 628
Elaeis, 474
Elaeocarpaceae, 607
Elaeocarpus, 608

Elastic, 444
Elastica, 241, 592
Elasticity, 774
Elasticus-a-um, 444
Elaterin, 709
Elaterium, 444, 709
Elaters, 82
Elder, 458

American, 706

black, 706

mountain, 706

red-berried, 706
Elecampane, 448, 720
Elemi, Bengal, 586

Manila, 586

resin, 586

West India, 586
Eleocharis, 444, 472
Elettaria, 444, 494
Eleusine, 467
Elm, 461, 512

American, 512

cross-section of wood, 346

family, 512

slippery, 513

white, 512
Eluteria, 444
Emarginate, 355
Emasculated, 451
Embryo-sac, 108, 120, 298
Emodin, 170
Emulsins, 243

Enchanter's nightshade, 634
Endocarp, 410
Endodermis, 310
Endosmosis, 251
Endosperm, 108, 127, 425

of date palm, 265

structure of, 429
Endospore, 12, 41
Endothecium, 404
Endothia radicalis, 54
Entada, 575
Enterolobium, 575
Entomophilous, 402
Environment, 130
Enzymes, 241

diastatic, 242
Eperua, 576
Ephemeral, 388
Epicarp, 410
Epicotyl, 299, 426
Epidermal cells, 277
Epidermis, 309, 369
Epigaea, 444, 644, 649
Epigeous shoot, 321, 322
Epigynous, 389
Epilobium, 634
Epipactis, 503
Epiphytes, 306
Equisetaceae, 444
Equisetales, 96
Equisetums, 96, 444
Equitant leaves, 349
Erectus-a-um, 444

INDEX.

787

Ergot, 52, 155, 441, 444
Ericaceae, 444, 644

microsublimates of,

173

Ericales, 644
Ericolin, 655
Erigeron, 444, 713
Eriobotyra, 562
Eriodendron, 611
Eriodictyon, 444, 670

hairs of, 284, 286
Erysimum, 445, 553
Erytaurin, 664
Erythraea, 664
Erythronium, 485
Erythrophlceum, 575
Erythroxylaceae, 580
Erythroxylon, 445, 580
Eschscholtzia, 547, 550
Esculentus-a-um, 445
Esparto, 472
Esters, 234
Estivation, 389
Etaerio, 419
Ether, phenol, 234
Euasci, 47
Eucalyptol, 631
Eucalyptus, 445, 631

kino, 631

oil, 631

seedling, 745

species of, 631
Eucitrus, 583
Eugenia, 445, 631
Eugenol, 234, 544, 546
Euonymus, 239, 445, 600
Eupatorin, 713
Eupatorium, 445, 712
Euphorbia, 445, 591, 592,

594

Euphorbiaceae, 590
Euphorbium, 593
Euphorbon, 593
Europaeus-a-um, 445
Euryale, 532
Evening primrose, 436, 634,

635

family, 634
Evergreen, 459
Evernia, 73
Evolution, 129, 247
Excelsin, 195
Excelsus-a-um, 445
Excoecaria, 592
Exine, 123, 404
Exocarp, 410
Exodermis, 309
Exogonium, 445, 668
Exosmosis, 251
Exospores, 41
Exothecium, 404
Experimental farms, 732-

735

Extraordinary ray, 774
Extrorse, 380

Fabiana, 684
Fagaceae, 511
Fagales, 510

Fagopyrum, 445, 526, 527
Fagus, 445

species of, 512
Fairy-ring fungus, 58
False beech-drops, 644

dissepiment, 378

flax, 439

hellebore, 462, 537

indigo, 435, 438

mitre wort, 460, 556

nettle, 438

Solomon's seal, 484, 485

spikenard, 484

unicorn root, 491

winter's bark, 622
Fan palms, 473
Farfara, 445
Farinosae, 480
Farinosus-a-um, 445
Farms, experimental, 732-

735

Fastigiatus-a-um, 445
Fats, 210

physiology, 216
Fatty oils, 546

resins, 238
Fegatella, 272
Fennel, 445, 639

flower, 453

protein in, 200
Ferments, 241

in stinging hairs, 287

in yeast, 49

microchemistry of, 245
Fern, flowering, 454

fossil, 104

male, 445

palms, in

sensitive, 453

used in medicine, 96

walking, 92

water, 94
Fertile, 121
Fertilis-e, 445
Fertilization, 125, 397
Ferula, 445, 639
Fetid, 445
Fever bush, 438

hay, 726
Fibers, bast, 268

isolation of, 270

sclerenchymatous, 268,270

strength of, 269
Fibrovascular strand, 313
Ficus, 241, 445, 513,514,515

ferment in, 244

latex in, 240

species of, 516
Field sorrel, 524, 525

penny cress, 553
Fig. 515

ferment in, 244

Fig, Indian, 626, 627

protein in, 199
Figwort family, 688
Fiji oil, 519
Filament, 379, 404
Filbert, 442, 510
Filicales, 87
Filix-mas, 445
Fir, 213, 434

California silver, na

red, 119

Scotch, 117

tannin in, 206

white, 119
Fisetin, 180
Fishberries, 539
Fish poison, 517, 539, 604,

606

Fistula, 445
Fixing agents, 755
Flacourtiaceae, 622
Flats, plant, 730
Flavon, 170
Flavone, 180
Flax, 450

family, 579
Flaxseed, oil in, 213

protein in, 199

structure of, 428
Fleabane, 444

Canada, 713

daisy, 713

Philadelphia, 713

sweet scabious, 713
Flea seed, 456 , -

Fleur-de-lis, 448
Floral envelopes, 382

leaves, 120, 375
Florets, 711
Florida moss, 480
Flour, gluten, 196

Graham, 196
Flower, 374
Flowers, classes of, 392

cleistogamous, 391

complete, 392

diagrams, 505

double, 390, 714

inner structure of, 402

insect, 718

ligulate, 395, 7H

of Angiosperms, 375

of Compositae, 387

of Gymnosperms, 375

of Solanaceae, 385

outer morphology of, 374

parts of, 374

stalks, 376, 402

sun, 447

tubular, 39 ', 711

types of, 3"3
Flueggea, 593
Fceniculum, 445, 639

aleurone grains of, 194
Foetida, 629

788

INDEX.

Foetidus-a-um, 445

Fog-fruit, 450

Folia Malabanthri, 568

Follicle, 419

Fontinalis, 85

Food, bird, 696

of plants, 248
Fore-leaves. 393. 466
Forget-me-not, 453, 670
Formaldehyde, 234
Forms of leaves, 354

of plants, alterations in,

332

Fossil Coniferae, 119
Fouquieria, 621
Four o'clock family, 528
Foxglove, 443, 690
Fragaria, 445, 566

fruit, 415

species of, 567
Fragilaria, 37
Fragrance due to volatile

oils, 234
Fragrans, 445
Fragrant, 445
Frames, cold, 731
Frangula, 445
Frangulin, 169, 170 w
Frankincense, 587
Frasera, 445
Fraseri, 446
Fraxetin, 66 1
Fraxin, 169, 170, 661
Fraxinus, 446, 66 1

glandular hairs in, 230
Fremontia, 615
French plum, 562
Fringe tree, 441, 661
Fructose, 154, 155
Fructosidase, 242
Fruit acids, 563

ethers, 564

jellies, 243

outer morphology of, 408

structure of, 421

sugars, 155, 563
Fruits, classification of, 421

different types of, 409
Fuchsia, 634
Fuchsin, as staining agent,

7S7

Fucose, 154
Fuller's teasel, 708
Fulvus-a-um, 446
Fumaria, 209, 446, 547, 550
Fumariaceae, 209
Fumarine, 548, 550
Fumitory, 446, 550

European, 550
Funaria, 85
Function of leaf, 350
Fungi, 7. 40

constituents of 41

coral, 58, 59

detection of, 70

Fungi, economic uses, 65

edible, 59

ferments of, 242, 244

gill,

glycogen in, 154

groups of, 41

imperfecti, 70

jelly, 59

leather, 59

poisonous, 6l

pore, 59

rust, 65, 68

smut, 65

stinck-horn, 59
Fungus chirurgorum, 65
Funifera, 627
Fusanus, 519
Fustin, 169, 170

Galactose, 169
Galangal, 494
Galbalus, 419
Galbanum, 639
Galeopsis, 446
Galetae, 388
Galium, 446, 697, 704
Gallicus-a-um, 446
Galls, 206, 334, 446, 511

Chinese, 597

crown, 335

fungus, 334

hard. 334

Japanese, 597

of Terminalia, 633

soft, 334

Gamboge, 597, 618, 619
Gamete, 5, 298
Gametophyte, 75, 108, 298
Gamopetalous, 385
Gamosepalous, 385
Garcinia, 446, 618, 619,

620
Garden bean, 576

beets, protein in, 199

heliotrope, 670

lilac, 661

pea, 576

rue, 585

strawberry, 566
Gardenia, 446, 704
Garlic, 435, 485

mustard, 553

protein in, 199
Gaultherase, 243, 644
Gaultheria, 446, 644, 650
Gaultherin, 169, 170
Gaylussacia, 446, 652

fruit, 414
Gelidium, 34
Gelsemium, 446, 661
Genista, 446, 574, 575
Gentian, 446, 663

American, 664

bottle, 663

closed, 663

Gentian family, 663
fringed, 664
horse, 706
rhizome of, 331
violet, as staining agent,

757

yellow, 663
Gentianaceae, 663
Gentianales, 660
Gentinin, 169
Gentisein, 180
Geotropism, negative, 320

positive, 302
Geraniaceae, 578
Geraniales, 577
Geraniol, 233, 564, 579, 583
Geranium, 446, 571
family, 578
fruit, 409
grass oil, 472
hairs in, 282
rose, 579

Geranyl acetate, 234
Gerardia, purple, 693
German chamomile, 715
Germander, 460
Germination, time of, 730
Geum, 446
Gigartina, 33, 446
Gilead balsam, 587
Ginger, 462, 494
beer, 49
family, 494
grass oil, 472
protein in, 200
starch in, 148
wild, 437, 520
Ginseng, 305, 454. 636, 638
cultivation of, 735
family, 636
Girardinia, 517
Githago, 446
Glaber-bra-brum, 446
Glabrous, 369
Glaeocapsa, 72
Glandular, 354
Glandulifer-a-um, 446
Glandulosus-a-um, 446
Glans, 420
Glaucium, 446, 550
Glaucous, 370
Glechoma, 681
Gleditschia, 575
Gliadins, 195
Globe artichoke, 726
Globoids, 193
Globulins, 192
Globulus, 446
Glosocapsa, 8
Gloiopeltis, 34
Gluco-alkaloids, 172
Glucose, 154
Glucosidal resins, 238
Glucosidase, 242
Glucoside, 155, 167

INDEX.

789

Glucoside, classification of,
169

dextrose, 169

distribution of, 169

function of, 172

microchemistry of, 171

rhamnose, 169
Glumes, 466
Glumiflorae, 466
Glutamin, 253
Glutelins, 194, 195
Gluten, 196

flour, 196

Glutinosus-a-um, 446
Glutinous, 446
Glycerin-jelly, 763
Glycine, 576
Glycinin, 195
Glycocoll, 192
Glycogen, 154
Glycoside, 167
Glycyphyllin, 169
Glycyrrhiza, 446, 568
Gnaphalium, 446
Gnidia, 627
Goa powder, 441
Goat's beard, 461
Goldenrod, 459, 712, 726

anise-scented, 722

nigh, 721

Golden seal, 448, 532 ;
Gold flower, 441
Goldthread, 442
Gonidium, 71
Goodyera, 503
Gooseberry, 457, 557

fruit, 418

protein in, 199

sugar in, 156
Goosefoot, 441, 527
Gossypitrin, 169
Gossypium, 447, 6iO

fiber, 269
Gouania, 447, 606
Gourd, 443

family, 708
Gracilaria, 34
Graham flour, 196
Grain, 417

pollen, 298
Graminales, 466
Gramineae, 447, 466
Granatum, 447, 629
Grape, 462, 606

fern, Virginia, 365

fruit, 584

protein in, 199

seed, oil in, 213

sugar, 155, 606

sugar in, 156

vine, 606
Grass, 447

beard, 436

family, 466

holy, 448

Grass of Parnassus, 556

panic, 454

pepper, 450, 553

scurvy, 442, 553

sweet vernal, 436

worm, 459
Gratiola, 447, 691
Gratiolin, 691
Graveolens, 446
Gravity, influence of, 301'
Greek valerian, 671
Grenadier's borax-carmine
solution, 760

haematoxylin solution,

760

Grevillea, 518
Grewia, 609
Grias, 629
Grifnthsia, 40
Grimmia, 85
Grindelia, 447, 713
Gromwell, 450
Groundsel, 459

tree, 437

Growing point, 253
Growth, factors influencing,

246, 247
Guaiac, 447

Guaiacum, 447, 580, 581
Guarana, 162, 447, 454, 603
Guarea, 516
Guava, 632
Guayava, 632
Guazuma, 615
Guelder-rose, wild, 704
Gulf weed, 31
Gum, 218, 565, 599

acajou, 599

anacardium, 223

arabic, 222, 569

balata, 659

chagual, 223

chewing, 659

chicle, 659

cocoa-palm, 223

East Indian, 223

exuding, 447

moringa, 223

plant, 447

red, 574

resin, 225, 236

spruce, 119

tragacanth, 218, 569, 570

tree, sweet, 558

yellow. 574
Gumbo, 611
Gummifer-a-um, 447
Gummy, 444
Gurjun balsam, 621
Gurjunic acid, 621
Gutta-percha, 241, 658
Guttiferae, 618
Guvacine, 474
Gymnocladus, 447, 575
Gymnosperms, 101

Gymnosperms, flowers of,

375

groups of, in
Gymnosporangium, 115
Gynaecium, 376
Gynandrous, 382
Gynocardia, 623
Gypsophila, 447, 531
Gysbertsiana, 621

Habenaiia, 447, 499, 500
Hadrome, 312
Haematoxylin, 180
Haematoxylon, 447, 571
Hagenia, 447, 565, 566
Hairs, abietiform, 287

candelabra, 287

crystal containing, 287

false plant, 290

glandular, 222, 228, 281

hooked, 286

lignified, 290

nonglandular, 283

papillose, 286

peltate, 286

plant, 279

shaggy, 285

stellate, 286

stinging, 287

types of, 281

uniseriate, 286
Hamamelidaceae, 558
Hamamelis, 447, 558, 559
Hanburii, 447
Hand microtome, 749
Hardening agent, 755, 756
Hard galls, 334
Hardhock, 459
Hard rush, 493
Hardwickia, 571
Harvesting of crops, 738
Hashish, 516
Haustoria, 306, 518
Haw, black, 704
Hawthorn, 442, 565
Hay fever, 726
Hazelnut, 442, 510

Chilian, 518

oil in, 213

protein in, 199
Hazelwort, 437
Head, 395
Heart's ease, 462
Heath, 444

family, 644
Heather, 439
Hedeoma, 447, 676
Hedera, 447, 636
Hederic acid, 636
Hedge hyssop, 447. 452;
Helenium, 447, 723
Helianthemum, 447
Helianthenin, 150, 726
Helianthus, 447, 725
Helicteres, 615

790

INDEX.

Heliotrope, 447

garden, 670
Heliotropism, 349
Heliotropium, 447, 670
Helixin, 636
Hellebore, 447

black, 537

false, 537
Helleborein, 537
Helleborus, 447, 537
Helonias, 491
Hemiasci, 47
Hemlock, 113, 461

poison, 442, 638, 640

tannin in, 205, 206

(Tsuga), 119

water, 441, 575, 642
Hemp, 439

fiber, 269, 514

nettle, 446

oil in, 213

sisal, 492

yellow, 625

Hempwood, climbing, 452
Henbane, 448, 684
Henequen, 492
Henna plant, 629
Hepaticae, 80, 447
Herb, annual, 329, 330

biennial, 330

perennial, 330

quinine, 664

Herba Centaurii Minoris,
664

cochleariae, 553
Herbaceous, 447
Herbaceus-a-um, 447
Herbs, 329
Hercules, club of, 441
Hermaphrodite, 392
Herniaria, 531
Hesperidin, 151. 169, i?o,

585

Hesperidium, 419
Hesperis, 447, 583

hairs in, 282
Heterocysts, n
Heterosporous, 87
Heuchera, 447, 556
Hevea. 241, 447, 592, 594
Hexose, 154
Hibiscus, 448, 611
Hickory, 333, 509

cross-section of wood, 346
Hicoria, 365, 509, 510
Hierochloe, 448, 472
High-bush huckleberry, 652
Hilum, 425

of starch grain, 144
Hinna, 629
Hippocastanaceae, 602
Hippocastanum, 448
Hirsute, 354
Hirsutus-a-um, 448
Hispid, 354

Hispidus-a-um, 448
Histology, i
Hoarhound, white, 676
Hold-fast, 30
Holly, 448

American, 600

Christmas, 600

dahoon, 600

European, 600

family, 600

leaved barberry, 436
Hollyhock, 435, 609, 611
Homalium, 623
Honesty, 553, 554
Honey, 402

dew, 157

poison, 402 ,

Honeysuckle, 450

bush, 443, 707

family, 704
Hopea, 621
Hop, hornbeam, 454

substitute, 606, 621

tree, 585
Hops. 448, SIS
Hordeum, 448, 467, 468
Horehound, fetid, 437

water, 451
Hornbeam, 440, 510
Horsebalm, 442

chestnut, 434, 448, 602

gentian, 706

mint, 679

radish, 553

tails, 96, 444
Hound's tongue, 443, 673
Houstonia, 448, 697
Hoyer's picro-carmine solu-
tion, 760
Huckleberry, 446, 654

black, 652

fruit, 414

sugar in, 156
Humulene, 508, 509
Humulus, 448, 514

hairs in, 282
Humus, 249
Hura, 592
Hyacinth, 485
Hydnocarpus, 623
Hydrangea, 448, 556

wild, 556
Hydrangin, 556
Hydrastine, 162, 770
Hydrastis, 161, 448, 532

alkaloids, 174, 175

farming, 734. 735
Hydrochinon, 176
Hydrodictyon, 22
Hydrophilous, 401
Hydrophyllaceae, 670
Hydropiper, 448
Hymenenasa, 574
Hymenium, 57
Hymenocallis, 448, 492

Hyoscyamus, 385, 448, 684

branching hairs in, 289

fruit, 409, 412

structure of seed, 429

tracheae of, 274
Hypecoum, 547
Hypericaceae, 618, 620
Hypericum, 448, 620
Hypha, 41
Hypnum, 85
Hypocotyl, 299, 426
Hypocrateriform, 388
Hypodermis, 309
Hypogeous shoot, 321, 325
Hyssop, 691

garden, 679

Hyssopus, glandular hairs
in, 230

hesperidin in, 153

Ice-plant, 529
Icthyomethia, 448
Idaeus, 448
Idioblasts, 207, 208
Ilex, 448, 600, 601
Ilicaceae, 600
Ilicin, 600
Illicium, 448, 540
Illipe, 659
Imbricated, 389
Impari-pinnate, 357
Impatiens, 448, 604
Imperfect flower, 392
Incumbent, 427
Indefinite inflorescence, 394
Index, refractive, 774
India Bdellium, 587

rubber, 516, 592

senna, 567
Indian cress, 579

cucumber, 485
root, 435

fig, 626, 627

hemp, 436

licorice, 434

mallow, 610

pipe, 452, 644

Suringi, 620

tobacco, 710

turnip, 477, 480
Indican, 169, 574
Indicus-a-um, 448
Indigo, 527, 573

blue, 180, 574

forming glucoside, 553

wild, 573
Indigofera, 573

tinctoria, 180
Indigotin, 180
Inflatus-a-um, 448
Inflorescence, 393, 394
Influence of gravity, 301
Infundibuliform, 388
Infusorial earth, 38
Inhambane copal, 574

INDEX.

791

Injury to plants, 172
Ink-ball, 335, 512

gall, 335, 512

tree, 597
Innate, 381

Inner structure of leaf, 365
of root, 309
of stem, 338
Inosit, 607, 636
Insect flowers, 718
Insect visitation of flowers,

399

Insectivorous plants, fer-
ments in, 244
Intine, 404

Intrafascicular cambium, 341
Inula, 387, 448, 720

hairs in, 288

phytomelane in, 261
Inulenin, 150, 726
Inulin, 150, 725
Inulinase, 242
Invertase, 242
Involucre, 395
Involute, 364
Iodine in seaweeds, 40

solution, 761

in water, 760, 761
lonon, 622
Ipecac, 448, 699

wild, 706

Ipecacuanha, 440, 448
Ipomcea, 448
Iridaceae, 492
Iridin, 169
Iris, 332, 448, 492
Iron solutions, 761
Irone, 234

Ironwood, 454, 510, 659
Irregular flower, 393
Irritability. 358
Irvingia, 586
Isatis, 553

Islandicus-a-um, 448
Isoetes, 97, 449
Isometric system, 764
Isoptera, 621
Isoquinoline, 166, 180
Isosporous, 87
Iva, 448
Ivory, vegetable, endosperm

in, 265
Ivy, 441, 447

English, 636

ground, 68 1

poison, 595, 596
Ixina, 449

Jaborandi, 449, 455, 582
Jacaranda, 691
Jack-in-the-pulpit, 477
Jack-tree, 516
Jalapa, 449

substitute, 528
Jamaica dogwood, 575

Jambosa, 631
Jambuse berries, 632
Japanese lacquer, 597

medlar, 562

aoy bean, 576
Japan-wax, 212
Jateorhiza, 539
Jatropha, 591
Jellies, fruit, 243
Jelly, Kaiser's glycerin, 763
Jequirity, 575
Jessamine, yellow, 661
Jewel-weed family, 604
Jimson weed, 443, 684
Joannesia, 591
Juglandales, 509
Juglans, 449, 509, 5io

cross-section of wood, 346
Juglansin, 195
Juglon, 179

Julocroton, hairs in, 282
Juncaceae, 493
Juncus, 493
Jungermania, 83, 85
Juniper, 116
Juniperus, 118
Jussieua, 634
Jute fiber, 269

Kadsura, 540
Kaiser's glycerin-jelly, 763
Kalmia, 174, 449, 648
Kamala, 449, 451, 592

hairs of, 285
Kapac oil, 6n
Kavaine, 508
Kava-kava, 177, 452, 508
Ketones, 234

Kidney bean, protein in, 199
Kiggelaria, 623
Killing agent, 755
Kinic acid, 655
Kino, 449, 569

American, 569, 571

Brazil, 593

eucalyptus, 631
Kittool, 476
Kittul, 476
Kiurushi, 597
Kleister, 145
Knot weed, 456
Kola nut tree, 614
Krameria, 449. 57 1
Kraunhia, 575
Kristallsand, 188
Kuhnia (Wisteria), 449
Kuhnistera, 449
Kumquat orange, 584

Labellum, 388
Labiatae, 449, 673
Laburnum, 575
Lac, 597

Japanese, 597

tree, 245

Laccase, 597
Laccases, 245
Lace-tree, 628
Lacinaria, 449, 722
Laciniatus-a-um, 449
Lacquer, black, 245

Japanese, 597

trees, 597
Lactarius, 65
Lactuca, 449, 712

milk-juice of, 241
Lactucarium, 241, 44* 712
Lady's mantle, 435

slipper, 443

thumb, 455
Laetia, 623
Laevulose, 155
Lafaensia, 628
Lagerstrcemia, 629
Lagetta, 628
Lamellae, 259

middle, 254

secondary, 255
Lamina, 348, 385
Laminaria, 30
Lamium, 449
Lanate, 354
Lanceolatus-a-um, 449
Landolphia, 241
Langsdorffia, 519
Langsdorffii, 449, 571
Laplaceae, 618
Laportea, 449, 517
Lappa, 449
Larch, tannin in, 206
Larix, 118

Larkspur, 443, 535, 574
Lateral branches, 312

root, 301, 312
Laterifolius-a-um, 449
Laticiferous vessels, 240
Latex, 238, 546
Lathyrus, 450, 576
Lauraceae, 450, 544
Laurel, 450, 544

bay, 461

great, 647

ground, 444

mountain, 648

noble, 544

nut, 212
oil, 619

sheep, 449, 648

spurge, 627
Laurus, 544
Lavandula, 450

hairs in, 282, 284
Lavender, 450, 676

pollen of, 404

sea, 450

spike, 676

true, 676

Lawsonia, 450, 629
Layer, resinogenous, 226
Leaf, apex of, 354

792

INDEX.

Leaf, base of, 356

bifacial, 366

climber, 324

dorsiventral, 366

functions of, 350

inner structure of, 365

margin of, 356

mold, formation of, 249

netted-veined, 353

outer morphology of leaf,
348

palmi-nerved, 353

parallel- veined, 352

reticulate, 353

simple, 348

teeth, glandular, 283

unifacial, 366

venation, 352
Leaflets, 356
Leather, dye, 633

wood, 444, 627
Leaves, 299, 348

anatomical differences in,
370

autumn, 178

bifacial, 349

compound, 356

cylindric, 349

decay of, 250

divergence of, 363

dorsiventral, 349

equitant, 349

foliage, 1 20

forms of, 354

modified, 364

movement of, 357

scale, 1 20

sporangial, 120

surface of, 353

sword-shaped, 349

texture of, 354
Lecanora, 74
Lecidea, 75
Lecithin, 214
Lecythidaceae, 629
Lecythis, 629
Ledum, 450
Leek, 485
Legume, 419
Legumelin, 195
Legumin, 195, 576
Leguminosae, 450, 567, 575
Lemna, 300
Lemnaceae, 450, 478
Lemon, 450, 584

oil, 584

protein in, 199
Lens, 450, 576
Lenticels, 291, 292
Lenticus, 450
Lentil, 450, 576

protein in, 199

starch in, 148

sugar in, 157
Lentus-a-um, 450

Lenzites, 62
Leontin, 538
Leonurus, 450, 682
Lepargyreea, 628
Lepidium, 450, 544
Lepidodendron, 100
Leptandra, 450
Leptilon, 713
Leptome, 276, 312
Leptospermum, 632
Lettuce, 449

poison, 712

Leucadendron, 450, 517
Leucaena, 575
Leuco-compounds, 179
Leucoplastids, 136, 137
Leucosin, 195
Leucospermum, 518
Leucothce, 648
Levisticum, 450, 643
Levo-glucose, 155
Levulose, 155, 563
Lianas, 324
Liane, 324, 602
Libriform, 270
Lichens, 71

color in, 179

economic uses of, 73

on Rhamnus Purshianus,
292

roots of, 73
Licorice, 568

fern, 96

section of, 271

Spanish, 568

wild, 704

Life-processes, 134
Light relation of leaves, 349

shoot, 329
Lignin, 256, 580
Lignocellulose, 256
Lignone, 256
Ligulate flower, 711
Ligule, 356
Liguliflorae, 711
Ligusticunij 450
Ligustrum, 450, 66 1
Lilac, 460

garden, 66 1
Liliaceae, 450, 485
Liliales, 485
Liliiflorae, 485
Lilium, 485
Lily, 450, 485

lotus, 453

of the valley, 442, 485, 487

spider, 448

yellow pond, 453
Lima beans, protein in, 199
Limb, 386
Lime fruit, 584

tree, 608
Limnophila, 358
Limonene, 583
Limonium, 450

Limonu-m, 450, 584
Linaceae, 450, 579
Linalool, 233, 564, 583
Linalyl acetate, 234
Linamarin, 169
Linaria, 691
Linariin, 691
Linden, 461, 608, 609

hesperidin in, 153
Lindera, 544
Linen, 580
Linodendron, 628
Linseed, oil in, 213
Linum, 579

structure of, 428
Lion's foot, 723
Lippia, 450, 673
Lippiol, 673
Liquidambar, 450, 558
Liquorice (see Licorice)
Liriodendrin, 540
Liriodendron, 450, 539
Lithospermum, 450
Litmus, 74
Litsea, 546

Liverworts, 76, 80, 82, 83
Lobed, 356
Lobelia, 384, 450, 710

blue, 710

red, 710

section of leaf, 370

seed-coat, 429
Lobeliaceae, 450
Loco, 574, 575
Loculicidal, 412
Locust, 457. 567, 576
Loeffler's methylene blue,

757

Logania, 450, 66r
Loganiaceae, 450, 661
Logwood, 571
Lomatia, 518
Lonchocarpus, 575
Lonicera, 450, 707
Loosestrife, 451, 628

purple, 628
Lophophora, 625
Lophophorine, 625
Loranthaceae, 450, 518
Loranthus, 518
Lotus, 450, 532
Lovage, 450, 643
Lucerne, 577
Luff a, 710
Luffa-sponge, 710
Lumen, false, 269
Lunaria, 450, 553, 554
Lungwort, 456
Lupeol acetate, 659
Lupine, 451, 574

seeds, lecithin in, 214
Lupinidine, 575
Lupinin, 575
Lupinine, 575
Lupinus, 451, 575

INDEX.

793

Lupinus luteus, protein in.

Mammey wine, 620* '

199

Mandarin, 584

root tubercles on, 307

Mandrake, 455

Lupulin, 515

Mangifera, 599

Lupulus, 451

Mango, 620

Lusitanicus-a-um, 451

Mangos, 599

Luteus-a-um, 451

Mangosteen, 446, 619

Luzula, 493

Mangostin, 619

Lychnis, 451, 531

Mangrove, American, 630

Lycoperdaceae, 59

forest, 304

Lycopodiaceae, 97, 45 1

swamps, 631

Lycopodium, 99, 213

Mangrovin, 588

Lycopus, 451

Manihot, 594

Lyngbya, 10

Manna, 155, 451, 565, 661

Lysigenous, 226

Briancon, 118

Lysimachia, hairs in, 282

of Israelites, 74

Lythraceae, 628

Persian, 155

Lythrum, 400, 451, 628

Mannit, 563

Mannitol, 155

Mabea, 592

Mannose, 169

Macaranga, 593

Manometer, 306

Macassar, 519

Maple, 434, 602

Mace, 212, 451, 543

sugar, 157

protein in, 200

syrup, 602

starch in, 148

Maracaibo balsam, 572

Macis (see Mace)

Maranta, 496

Maclura, 451, 516

arrow root, 496

Maclurin, 180

Marantaceae, 496 -

Macrocystis, 30

Marasmius, 58

Maculatus-a-um, 451

Marcescent, 388

Madder, 697, 702, 703

Marcgravia, 617

Mad-dog skullcap, 675

Marcgraviaceae, 616

Magnolia, 451, 539, 540

Marchantia, 81

Magnoliaceae, 539

Marginal, 451

Magnolin, 540

Marginalis-e, 451

Magonia, 604

Marginicidal, 411

Mahogany family, 588

Margin of leaf, 356

tree, 589

Mariana, 451

Mahonia, trailing, 537

Marigold, 387, 7i8

Mahurea, 619

bur, 438

Maidenhair, 434, 439

marsh, 439

Maize, 462

Marilandicus-a-um, 452

Majalis, 451

Maritimus-a-um, 451

Majorana, 451

Marjoram, 451

Major-us, 451

sweet, 679

Malabanthri folia, 568

wild, 454, 679

Malambo bark, 592

Marking tree, East Indian,

Male generative-cell, 298

597

Mallotus, 451, 591

Marmelos, 451

hairs of, 285

Marrubium, 451, 676

Mallow, 609, 611

Marsdenia, 66P

glade, 453

Marsh elder, 448

Indian, 610

Marshmallow, 435, 609

rose, 448

Marsilea, 451

Malpighia glabra, tannin in,

Marsilia, 94, 95

206

Marsupium, 451

Malpighiaceae, 589

Marvel-of-Peru, 528

Maltase, 242

Massoy bark oil, 546

Maltose, 155

Mastic, 452, 599

Malva, 611

tree, 450

Malvaceae, 451, 609

Mastigocoleus, 8

Malvales, 607

Mat6, 600

Mamillosus-a-um, 451

germination of, 730

Mammea, 620

Matico, 452, 504

Mammei apple, 620

section of leaf, 371

Matisia, 612
Matricaria, 452, 715
Mawseed, 547
May apple, 538
Mayflower, 649
Maysin, 195
Maytenus, 602
May weed, 442
Meadow beauty, 634

sweet, 459
Meal, mountain, 39
Measurement, microscopic,

7S4

Medeola, 485
Medicago, 577

ferment in, 244
Medicinal plants, cultivation

of, 727

Medicus-a-um, 452
Medinilla, 634
Medlar, Japanese, 562
Medullary rays, 314
Megasporangium, 108, 298,

375
Megaspore, 86, 298

germination of, 298
Megasporophylls, 108, 375
Melaleuca, 452, 632
Melastoma, 634
Melastomataceae, 633
Melia, 588
Meliaceae, 588
Melibiose, 155
Melilotus, 452
Melissa, 452, 679
Melon, 441, 454

cucumber, 443

musk, protein in, 199

tree, 624

Membrane, primary, 255
Memecylon, 634
Mendel's Law, 132
Menispermum, 539
Menispermaceae, 538
Menispermum, fibrovascular
bundle of, 337

woody vine of, 322
Menispine, 539
Mentha, 452, 678, 384

species of, 676
Menthol, 233

Menyanthes, 452, 664, 665
Menyanthin, 664
Mercurialis, 452, 593
Mercuric chloride, as fixing

agent, 756
Mericarp, 417
Meristems, 253, 254, 291
Mermaid's hair, 10
Mescal, 492

buttons, 625
Mescaline, 625
Mesembryanthemum, 529
Mesocarp, 410
Mesophyll, 366

794

INDEX.

Mestome, 272

sheaths, 367

strand, 313, 341, 342, 343
Mesua, 619
Metabolism, 252
Metachlamydeae, 504, 643
Methyl salicylate, 234
Methylene blue, as staining

agent, 757

Methysticin, 177, 508
Methysticum, 452, 508
Metroxylon, 475
Meum, 452

Mexican linaloe oil, 588
Mezereum, 443, 452, 627
Michelia, 540
Microcarpus-a-um, 452
Micrococci, 14
Micrometer, 754
Micrometry, 754
Micron, 754
Micro-polariscope, 764
Micropyle, 425
Microscope, ultra, 765
Microscopic measurement,

754

Microsomata, 136
Microsomes, 136
Microspermae, 496
Microsporangia, 120, 298
Microspore, 298, 375

germination of, 298
Microsporophylls, 105, 375
Microtome, 749
Midrib, 353

Mignonette, 120, 457, 554
Mikania, 452
Milaceus-a-um, 452
Mildews, 44
Milfoil, 434
Milk, clotting of, 244

juice, 238

ropy, 244

vetch, 437
Milkweed, 437

family, 668
Milkwort, 455

family, 589

white, 589
Millefolium, 452
Millet, starch in, 148
Millettia, 575
Millimeter, 754
Mimosoideae, 567
Mimusops, 659
Mineral cellulose walls, 258
Mint, 449, 452

cat, 453, 680

family, 673

horse, 452
Mio Mio, 723
Miocene, 117
Mirabilis, 528
Mistletoe, 450

American, 531

Mistletoe, European, 518

family, 518

oak, 518

Mitchella, 452, 697, 704
Mitella, 452, 556
Mitrewort, 452, 556

false, 556

Moccasin flower, 498
Mock orange, 556
Modified leaves, 364

roots, 306
Mold, black, 45

water, 42
Mollis-e, 452
Monandrous, 381
Monarda, 452, 679

oil, 680

Monkey-bread tree, 612
Monkey-pot tree, 629
Monkshood, 434
Monniera, 452
Monocarpia, 542
Monoclinic crystals, 183, 184
Monocotyledons, 120, 463
Monoecious, 392
Monosaccharose, 154
Monotropa, 452, 644
Montanus-a-um, 452
Moonseed, Canada, 322, 539

family, 538
Moonwort, 438, 450
Moraceae, 513
Morchella, 58
Morel, 58
Morinda, 704
Morindin, 170, 704
Moringa, 223, 554

pterygosperma, 212
Moringaceae, 554
Morning glory, 448, 668
Morphine, 547
Morphology, i
Morus, 452, 517
Moss, bird's nest, 103

club, 97, 451

groups, 84

Iceland, 73, 440

Irish, 31

reindeer, 74

scale, 83

sea, 441, 446
Mother-clove, 631
Motherwort, 450, 682
Mould (see Mold)
Mountain ash, 459

elder, 706

laurel, 648

Mounting of specimens, 762
Mounts, permanent, 763
Mourera, 556
Movements of leaves, 357
Moxa, 725
Mucedo, 45
Mucilage, 218, 565

chemical classification, 222

Mucilage, forms of, 221

in sassafras, 263

walls, 257
Mucor, 45
Mucuna, 452, 576
Mugwort, common, 719
Mulberry, 452

black, 517

family, 513

fruit, 409

white, 517
Mullein, 691

hairs of, 286
Mundulea, 575
Muntingia, 609
Muricatus-a-um, 453
Musa, 496
Musaceae, 496
Musci, 84
Mushrooms, 434

common, 59

edible, 58

lecithin in, 214

poisonous, 58

propagation, 56
Muskmallow, 434
Musk-melon, 710

protein in, 199
Musk seed, 611

substitute, 611
Mustard, 438, 459

ball, 453

black, 552, 553

family, 551

fruit, 409

garlic, 553

hedge, 459, 553

protein in, 199, 200

treacle, 445, 553

white, 552, 553

wild, 553

yellow, germination of,

299

Mutation, 132, 247
Mycelium, 41
Mycose, 155
Myelin, forms, 215
Myosotis, 453, 670
Myrcene, 632
Myrceugenia, 632
Myrcia, oil, 632
Myrica, 211, 453, 508, 509

cerifera, 212

Nagi, tannin in, 206

species, 508, 509
Myricaceae, 508, 509
Myricales, 508, 509
Myricaria, 621
Myricin, 594
Myristica, 453, 543
Myristicaceae, 543
Myristin, 691
Myrobalans, 633

beleric, 633

chebula, 633

INDEX.

795

Myrobalans, long, 633

Node, 320

(Edogonium, 25

tannin in, 206

Nomenclature, 2

CEnanthe, 643

Myrosin, 243

Botanical, 430

(Enothera, 453, 634, 635

Myroxylon, 623

Nopalea, 627

Officinalis-e, 453

Myrrh, 442, 453, 586, 587

North American papaw, 542

Oil, ajowan, 609

Myrtaceae, 631

Nostoc, ii

apeiba, 643

Myrtales, 627

Nucellus, 108, 124, 298

apopin, 234

Myrtiflorae, 627

Nucleo-proteins, 194

bay, 632

Myrtle family, 631

Nucleoles, 136

ben, 212

tree, 453

Nucleus, 2, 136

benne, 691

wax, 212, 453

function of, 140

bergamot, 584

Myrtus, 453, 632

of starch grain, 144

bigardia, 584

Nuphar, 531

cajeput, 632

Nabalus, 723

Nupharine, 531

candle nut, 213

Naiadaceae, 466

Nut, 420

carapa, 589

Naiadales, 466

Nutation, 358

cedar, as clearing agent,

Naked flowers, 393

Nutgall, 334, 446

757

Napaca, 453

Nutlet, 420

cedar-wood, 589

Napaea, 612

Nutmeg, 212, 453, 542, 543

chaulmoogra, 214, 623

Napellus, 453

protein in, 200

cineol containing, 544

Naphthalene, derivatives,

starch in, 148

clove, as clearing agent,

179

Nux-vomica, 453, 661

757

Naphthol black B., 183

endosperm of, 265, 428

coccos, 623

Narcissus, 453, 492

hairs of, 286

cocoa-nut, 212

Nardus, 453

Nyctaginaceae, 528

Coniferae, 119

Naringin, 169, 170, 585

Nyctinastic, 361

cotton seed, 611

Nasturtium family, 579

Nyctitropic, 361

Crotdn, Mexican, 591

Natural selection, 131

Nymphaea, 453

cumin, 643

Navel orange, 584

Nymphaeaceae, 531

curcas, 591

Navicola, 37

Nyssa, 453

dill, 643

Nectandra, 453, 546

Nysso, 518

essential, as clearing agent,

Nectar, 402

757

apparatus, 408

Oak, 457, 5"

Eucalyptus, 631

poisonous, 402

acorns, 148

fatty, 546

Nelumbo, 453, 532

sugar in, 157

Fiji, 519

Nepenthaceae, 555

bark of, 295

fixed, 210

Nepenthes, 555

black, 512

as a reserve, 217

Nepeta, 453, 680, 681

mistletoe, 518

function of, 235

Nephelium, 603

poison, 595

globule, detection of, 752

Nerium, 668

western, 597

kapac, 611

Neroli, 583

red, 512

laurel-nut, 619

Nerved leaf, 352

tannin in, 206

lemon, 584

Nerves, 352

tannin in, 206

marjoram, as clearing

Nesaea, 628

white, 511, 512

agent, 757

Neslia, 453, 554

tannin in, 206

massoy bark, 546

Nessin, 628

Oats, 437

Mexican linaloe, 588

Netted-veined leaf, 353

protein in, 199

Monarda, 680

Nettle, 461, 517

starch in, 148

myrcia, 632

dead, 449

structure of, 423

Neroli, 583

horse, 684

sugar in, 157

non-drying, 691

small, 517

Obcordate, 355

olive, 213, 660

stinging, 287, 517

Obtuse, 355

orange peel, 583

wood, 449

Obtusifolius-a-um, 453

palm, 211, 474

Nicotiana, 453, 688

Occidentalis-e, 453

palm-nut, 212

Nicotianin, 688

Ochrocarpus, 619, 620

pepper, Japanese, 585

Nicotine, 688

Ochroma, 612

rose, 564

Nigella, 453

Ocimum, 679

sandal, 518

Niger-gra-grum, 453

Ocotea, 546

santal, Australian, 519

Nigger-toe, 630

Ocotilla, 621

sesame, 691

Night-blooming cereus, 625

wax, 621

spike, 679

Nightshade, 459

Ocrea, 520

sweet anise, 643

deadly, 684

Octomeles, 625

tunga, 213

enchanter's, 441, 634

Ocular micrometer, 754

turpentine, as clearing

Nitrogen bacteria, 307

Odontorhizon, 453

agent, 757

Nobilis-e, 453

Odoratus-a-um, 453

volatile, 225

796

INDEX.

Oil, volatile, botanical clas-

Orange, protein in, 199

sification, 232

root, 448

characteristics of, 231

Seville, 583

composition, 233

sugar in, 156

culture of plants yield

sweet, 583

ing, 747

Orcein, 74

formation, 235

Orchid, 496

micro-chemistry of, 231

Orchidaceae, 496

water fennel, 643

Orchidales, 496

Okra, 611

Orchil, 75

Olea, 660

Orchis, fringed, 447

Oleaceae, 453, 660

round-leaved, 499

Oleander, 668

white fringed, 500

cork in, 293

Orcin, color in, 179

Oleandrin, 668

Ordinary ray, 774

Oleo-resin, 225

Orellin, 622

Oleum, 453

Organography, I

Cedralae, 589

Organs, nutritive, 3

Lavandula, 676

plant, 3

Rosmarinus, 676

sexual, 3

Theobromatis, 612

vegetative, 3

Oleuropein, 661

Orientalis-e, 454

Olibanum, 587

Origanum, 454, 679

American, 587

Cretian, 679

Olive, 453, 660

oil, 679

family, 660

Orlean, 621

oil, 660

Ornithogalum, 485

tree, 660

Ornus, 454

Onagraceae, 634

Orobanchaceae, 696

Onion, 435. 485

Orpine family, 556

sea, 461

Orris root, 332, 492

sets, 327

starch, 143

starch in, 148

Orthotoschies, 363

sugar in, 157

Oryza, 467

Onoclea, 92, 453

Oscillaria, 10

Ononidis, 576

Oscillatoria, 10

Ononis, 576

Osmosis, 251

Ontogeny, 130

Osmunda, 365, 454

Oogonium, 5

Ostrya, 454, 510

Oomycetes, 42

Otaheite orange, 584

Oosphere, 5

Ovary, 120, 376

Oospore, 5

tissues of, 406

Opegrapha, 75

Ovules, 376, 378

Operculina, 453

development of, 124

Operculum, 79

forms of, 379

Opium, 241, 453

positions of, 379

collection of, 549

Oxalidaceae, 579

poppy, 546, 547

Oxalis, 454, 579

Optical reactions, 773

Oxidation, 252

Opulus, 454

Oxyacanthine, 539

Opuntia, 454, 626, 627

Oxycedrus, 454

Opuntiales, 625

Oxycoccin, 656

Orange, 437, 441, 582

Oxycoccos, 656

bitter, 583

Oxydases, 245

blood, 584

Oxygen, 252

Curacao, 583

in fucus, 28

G. G., 182

Oxymethylanthraquinone,

kidney-glove, 584

176

kumquat, 584

Malta, 583

Pachira, 611

mock, 455, 556

Paeonia, 454

navel, 584

Palaquim, 658

osage, 451, 516

Pale, 466

otaheite, 584

Palisade tissue, 366

Portugal, 583

Palmae, 473

Palmately-compound, 356
Palmately-veined leaves, 353
Palmatus-a-um, 454
Palmetto, 458

saw, 459

Palmi-nerved leaf, 353
Palm oil, 474
Palms, 473
Palustris-e, 454
Panax, 305, 454, 636, 638
Pandanales, 463
Pangium.igS, 623
Panicles, 396
Paniculatus-a-um, 454
Panicum, 454
Pansy, 622
Papain, 244, 542, 624
Papaver, 454, 546, 547
Papaveraceas, 546
Papaverales, 546
Papaw family, 624

ferment in, 244

North American, 437, 542

tree, 624
Papayotin, 624
Paper, Chinese rice, 636
Papilionaceous, 386
Papilionatae, 567
Papillae, 451
Pappus, 711
Paprika, protein in, 20O
Papyrifer-a-um, 454
Paracatechin, 607
Para cress, 724
Paradise grains, 494
Parallel-veined leaf, 352
Para-nut, 629, 630
Parasites, 40
Pareira, 539
Parenchyma, forms of, 262

rays, secondary, 314

sheaths, 367
Paricine, 546
Parietales, 615
Pari-pinnate, 357
Parnasia, 209, 556
Paronchia, 531
Parrya, 553
Parsley, 455

garden, 643

Parsnips, protein in, 199
Partridge berry, 697
Parviflorus-a-um, 454
Pasque flower, 456
Passiflora, 454, 623
Passifloraceae, 623
Passion flower, 454, 615, 623,
Patchouli oil, 679
Patchouly, 679
Pauciflorus-a-um, 454
Paullinia, 454, 603
Paviin, 602
Payena, 659
Pea, 198, 576

everlasting, 450

INDEX.

797

Pea, garden, 576

germination of, 299

lecithin in, 214

protein in, 199

starch in, 148

sweet, 576
Peach, 435, 562

oil in, 213

protein in, 199

sugar in, 156
Peanut, 199, 576

oil in, 213

plant, 401
Pear, 457, 562

prickly, 454, 526, 627

protein in, 199
Peat, bog, 250

upland, 250
Pectase, 243
Pectin, 243, 563

origin of, 255
Pectinase, 243
Pectose, 243, 563
Pedaliaceae, 691
Pedatus-a-um, 454
Pedicel, 393
Peganum, 581
Pelargonium, 579
Pellitory, 435, 457, 714
Pellotine, 625
Pelosine, 546
Peltatus-a-um, 454
Pencils, 117
Penicillium, 49
Pennatifolius-a-um, 454
Penny cress, field, 553
Pennyroyal, 447

American, 676
Pentalostigma, 593
Pentapetes, 615
Pentastichous, 363
Penthorum, 454, 556
Pentose, 154
Peony, 454
Pepo, 420, 454, 708
Pepper, 455

African, 687

black, 504, 505

cayenne, 200, 687

grass, 553

long, 504

moor, 585

picking, 567

protein in, 200

red, 439, 688

starch in, 148

water, 448

white, 504
Pepperidge, 453
Peppermint, 676, 678

camphor, 233

culture, 746
Peramium, 503
Pereirae, 454
Perennial herb, 330

Perezia, 723
Perfect flower, 392
Perfoliate, 356, 454
Perfoliatus-a-um, 454
Perforatus-a-um, 455
Perianth, 382
Periblem, 253
Pericambium, 312
Pericarp, 410
Pericycle, 312
Periderm, 291
Perigynous, 389
Perisperm, 425

structure of, 429
Peristome, 79
Periwinkle, 668
Permanent mounts, making

of, 763

Peronospora, 43
Persea, 455
Persian tobacco, 688
Persicaria, 455
Persimmon, 444, 660

fruit, 659

Japanese, 660
Persistent, 388
Personate, 388
Persoonia, 518
Pertusaria, 73
Petals, 120, 374, 382
Petiole, 348
Petroselinum, 455, 643
Peziza, 46
Phaea, 575
Phaeophyceae, 17, 28
Phaius, 137
Phallacese, 59
Phanerogams, 5
Phaselin, 195
Phaseoleae, hairs in, 282
Phaseolin, 195
Phaseolus, 455, 576

apical region, 321
Phasins, 198
Pheasant's eye, 434
Phellandrene, 632, 643
Phellogen, 290, 291, 313
Phenol, derivatives, 179
Phenolases, 245
Phenols, 234

Phenyl ethyl alcohol, 564
Philadelphia fleabane, 713
Philadelphus, 455, 556
Phillipinensis-e, 455
Phlobaphene, 203
Phloem, 312
Phloridzin, 169, 565
Phloroglucin, crystals, 762

reaction, 256

solution, 761
Phlox, 455, 670

tracheae of, 274
Phoenix, 475

endosperm in, 265
Phoradendron, 518

Phospholipines, 217
Photosynthesis, 137, 299,
350

fixed oils in, 210
Phycocyanin, 8
Phycomycetes, 42
Phyllanthus, 593, 594
Phyllotaxis, 363
Phylogeny, 129
Physica, 73

Physical basis of life, 138
Physiological experiments,

350

Physiology, i
Physostigma, 455, 572
Phytelephas, 473

endosperm in, 265
Phyto-bezoars, 626
Phyto-cecidien, 334
Phyto-globulins, 193, 197
Phytolacca, 455

leaf, section of, 369

root, section of, 318
Phytolaccaceae, 528
Phytomelane, 258
Phytosterol, 214
Phytovitellins, 193
Pianeze III b, 70
Picea, 109, 119, 455
Pichi, 684
Pickerel weed, 482
Picramnia, hairs in, 282
Picrasma, 455, 585
Picric acid, 756
Picric-sulphuric acid, as fix-
ing agent, 756
Picro-crocin, 493
Picrotoxin, 455, 539
Piereskia, 627
Pieris, 648

hairs in, 282
Pigments, 138

resins, 238

respiration, 181
Pignone, 117
Pignut hickory trees, 333
Pigweed, 441
Pileus, 57

Pilocarpus, 455, 582
Pimelea, 627
Pimenta, 455, 632

starch in, 148
Pimpernel, 436, 455
Pimpinella, 455, 639
Pinaceae, groups of, 113
Pinanga, 621
Pine, 455

Cuban, 113

frankincense, 112

great sugar, 112

loblolly, 112

long-leaved, 113

nut, 117

oil in, 213

pitch, 112

798

INDEX.

Pine, prince's, 644

seeds, 117

spruce, 112

sugar, 117

swamp, 113

torch, 112

Weymouth, 106

white, 106

yellow, 113
Pineapple, 436, 480

ferment in, 244
Piney resin, 621
Pinguicula, ferment in, 244
Pink, 443, 531

Carolina, 66 1

cultivated, 531

lady's slipper, 498

root, 459

Pinkster flower, 646
Pinnately-compound, 356
Pinus, 455

Strobus, 1 06

sylvestris, 213

tannin in, 206
Piper, 426, 455, 504, 506
(see also Pepper)

methysticum, 177

species of, 504
Piperaceae, 504
Piperales, 504
Piperine, 161

crystals, 771
Piperitus-a-um, 455
Pipitzahoic acid, 723
Pipsissewa, 455, 644
Pircunia, 528
Pirolaceae, 644
Piscidia, 575
Piscipula, 455
Pistachio, 455, 599
Pistacia, 208, 455, 597
Pistil, 120, 376

compound, 376

different types of, 377

simple, 376
Pistillate, 392
Pisum, 576

ferment in, 244

germination of, 299
Pitch, Burgundy, 119

Canada, 119
Pitcher-plant, 361, 458, 555

family, 554
Pith, sassafras, 263
Pithecolobium, 575
Pityrodia, hairs in, 282
Placenta, 377

structure of, 408
Plaited, 389
Planchonia, 629
Plane tree family, 559
Planifolius-a-um, 455
Plant hairs, 353

henna, 450
Plantaginaceae, 696

Plantago, 455, 694, 696

ferment in, 244
Plantain, 455, 694

common, 694

family, 696

flowers, 400
Plastids, 2, 138
Platanaceae, 559
Platanus, 559
Plates, sieve, 276
Platinic chloride, 165
Platonia, 620
Pleistocene clays, 117
Plerome, 253
Pleurisy-root, 667, 668
Pleurococcus, 20
Pleurosigma, 36
Plicate, 364, 389
Plum, 456

French, 562

grape, 606

oil in, 213

protein in, 200

sugar in, 156
Plumule, 127, 426
Pod, 420
Podophyllum, 455, 538

rhizome of, 324
Podostemaceae, 556
Podostemon, 455. 556, 679
Point of origin of growth,
144- 300

of vegetation, 300
Poison, arrow, 575, 593, 597,
633, 662

curare, 539

fish, 539, 575, 604, 606

ivy, 595, 596

oak, 595

snake, antidotes, 539
Poke weed, 455
Polariscope, micro, 764
Polemoniaceae, 670
Polemoniales, 668
Polemonium, 455, 670, 676

family, 670
Pollantin, 726

Pollen, 120, 122, 298, 375,
404, 726

composition of, 726

method of gathering, 722

pine, 107

sac, 298

toxic, 726

tube, in

weight of, 726
Pollination, in, 125, 397
Pollinia, 123
Polygala, 172, 455, 589
Polygalaceae, 589
Polygamous, 392
Polygamus-a-um, 456
Polygonaceae, 520, 574
Polygonales, 520
Polygonatum, 456, 483

Polygonatum, rhizome of,

. 325

Polygonum, 456, 525, 527
Polymnia, 720
Polynesia, 631
Polypeptides, 199
Polypodium, 456
Polypody, 456
Polyporaceae, 59
Polyporus, 456

resins in, 237
Polytrichum, 77, 78, 85
Pome, 420

Pomegranate, 447, 457, 620-
Pomelos, 584
Pometia, 603
Pond lily, yellow, 531
Pond-weed family, 466
Pontederia, 482
Pontederiaceae, 480
Poplar, 456, 508
Popowia, 542
Poppy, 454, 548, 549

California, 547

celandine, 550

family, 546

horned, 446

Mexican, 547

oil, 547
in, 213

opium, 546, 547

prickly, 436

yellow, 550
Populin, 169, 170, 508
Populus, 456, 508

species, 508
Pores, bordered, 275

sieve, 276

simple, 263

water, 279
Port wine, 607

coloring of, 529
Portulaca, 551
Portulacaceae, 531
Potassium hydrate, crystals,
762

iodide, crystals, 762
Potato, 688

Chinese, 492

family, 683

phyto-globulins in, 194

plant, 688

protein in, 199

starch, 142, 148
in, 148

manufacture of, 148
with polariscope, 146

substitute, 726
Potentilla, 365, 456, 565
Potometer, 351
Pouzolzia, 517
Pratensis-e, 456
Precatorius-a-um, 456
Prefloration, 389
Prefoliation, 364

INDEX.

799

Preservatives, 755

Psidlum, 632

Prickly pear, 626

Psoralea, 456, 574

Pride of China, 588

Psyllium, 456

Primary root, 301

Ptelea, 456, 585

cross-section of, 310

Pteridophytes, 86

structure, 309

Pteris, 456

of dicotyledonous roots,

Pterocarpus, 456, 569, 571

345

Pterospermum, 615

of stem, 338

Puber-a-um, 456

summary, 345

Pubescens, 456

summary, 317

Pubescent, 353

Primeverase, 658

Puccinia graminis, 69

Primeverin, 658

Puccoon, 450

Primrose, 456

Puffball, 58, 59

evening, 453, 634, 635

Pulegioides, 456

family, 656

Pulegone, 234

Primula, 456, 656, 657

Pulicaria, 456

structure of flower, 407

Pulmonaria, 456

Primulaceae, 656

Pulque, 492

Primulales, 656

Pulsatilla, 456, 537

Primulaverin, 658

Pulse, 450

Prince's feather, 527

family, 567

pine, 644

Pulvinis, 360

Principes, 473

Pumpkin, 454

Privet, 450, 66 1

protein in, 200

Procumbens, 456

sugar in, 156

Prolamins, 194, 195

vine, 709

Promycelium, 66

Punica, 457, 629

Propagation by cutting, 733

Punicaceae, 629

Propagative organs, 298

Purging cassia, 567

Prophylla, 393

Purine, 167

Protaceae, 517

Purple cone-flower, 724

Protea, species of, 518

gerardia, 693

Proteacin, 517

Purpureus-a-um, 457

Proteales, 517

Purshia, 565

Protection of plants, 172

Purshianus-a-um, 457

Proteinase, 244

Purslane, 531

Proteins, 192

Putamen, 410

classification of, 193

Pycnidia, 73

origin of, 198

Pycnoconidia, 73

percentage of, 199

Pyrenoids, 17, 149

toxic, 196

Pyrethri Flores, 718

Protium, 586

Pyrethron, 718

Protococcus, 20

Pyrethrum, 457

Protonema, 78

Pyridine, 166

Protopine, 548, 55O

Pyrocatechol, 204

Protoplasm, 2, 134

Pyrogallol, 204

Protoplasmic movement, 26

Pyrola, 174

Protoplast, 2, 134

Pyrone, 180

Prulaurasin, 169

Pyrrolidine, 166

Prune, 562

Pyrus, 457, 562, 565

protein in, 200

quercitin, 562

sugar in, 156

Pyxidium, 413

Prunifolius-a-um, 456

Pyxis, 413, 630

Prunum, 456

Prunus, 560, 562, 565

Quassia, 455. 457, 585, 586

cork of, 294

Jamaica, 585

ferments in, 243

Quebracho, 667

section of wood, 346

bianco, 457

Pruriens, 456

Colorado, 599

Pseudo-^Egle group, 583

extract, tannin in, 206

Pseudococcus, 627

Queen's root, 590

Pseudoinulin, 150

Quercitin, 169, 179, 180, 508,

Pseudomonas, 307

512, 562. 565

Pseudotsuga, 114

Quercitrin, 170

Quercus, 457, 512

bork of, 295

galls on. 335
Quillaja, 172, 457, 564
Quillwort, 449
Quina blanca, 592
Quince, 560, 562, 565

Bengal, 451
Quinine herb, 664
Quinoline, 166
Quisqualis, 633

Raceme, 394
Racemosus-a-um, 457
Radial flower, 393
Radial-longitudinal section,

749

Radiate head, 711
Radicans, 457
Radicle, 426
Radish, 457

color in, 178

protein in, 199
Ragweed, 435, 459, 726
Rain trees, 157
Raisin, 606, 607

sugar in, 156
Rajania, 492
Ramie, 269, 517
Ranales, 531
Ranunculaceae, 532
Ranunculus, 457, 537

ferment in, 244
Rape-seed, protein in, 199
Raphanus, 457, 553
Raphia, 269
Raphides, 186
Raspberry fruit, 415

protein in, 200

red, 563

sugar in, 156

syrup of, 563
Rattle-box, 442, 575
Rattlesnake plantain, 503
Rattleweed, 574
Ravensara, 546
Ray-flowers, 395, 711
Reactions, optical, 773
Reagents, 755

alkaloidal, 163

Mayer's, 164

Sonnenschein's, 164

special, 755

Wagner's, 164

Wormley's, 165
Reaumuria, 621
Rebandin, 713
Receptacle, 375

secretory, 226
Reclinate, 364
Red gum, 574

raspberry, 563

root, 440

wine, 607
Reed. 439. 445

8oo

INDEX.

Refractive index, 774
Regular flower, 393
Repand, 356
Repens, 457
Reptans, 457
Reseda, 457, 554
Resedaceae, 554
Resene resins, 237
Reserve layers, 425
Resin, 236, 255

balsamic, 225

chaia, 621

fossil, 237

micro-chemistry of, 231

origin of, 238

piney, 621

soft, 587

Resinol resins, 237
Resinolic acid resins, 237
Resins, origin of, 238
Respiration, 350
Reticulate, 354, 457
Reticulatus-a-um, 457
Retuse, 355
Rhamnetin, 180
Rhamnose, 154, 562
Rhamnus, 457, 604

bark of, 342

fruit, 422

wood of, 344
Rhapontic, 457
Rhaponticus-a-um, 457
Rhatany, 449
Rheedia, 619
Rhein, 170
Rheum, 457, 521

species, 522
Rhexia, 634
Rhipsalis, 627
Rhizogenous layer, 312
Rhizome, 325
Rhizophora, 304, 630
Rhizophoraceae, 630
Rhodeose, 169
Rhododendron, 457, 646

glandular hairs in, 230

hairs in, 282
Rhodophyceae, 17, 31
Rhodymenia, 34
Rhceadales, 546, 554
Rhubarb, 457, 522

garden, 522

South China, 522
Rhus, 457, 595, 596, 597, 598

ferment in, 245

hairs of, 280, 284

poisonous, 597

species of, 597

tannin in, 206
Rhynchanthera, 634
Ribes, 457, 558

fruit, 418
Riccia, 82
Rice, 467

protein in, 199

Rice, starch in, 148
Ricin, 195, 196, 590, 611
Ricinus, 196, 457, 591

aleurone grains of, 194,
428

ferment in, 244

fruit, 410

protein in, 199

seed, 426
Ringent, 388
Riuno-kiku, 726
River-weed, 455

family, 556
Rivinia, 528
Robin, 198

Robinia, 457, 574, 576
Robinin, 169
Robustus-a-um, 457
Roccella, 74
Rocket, 447
Rockrose, 447
Rockweeds, 28
Roman chamomile, 713
Root, 299

abnormal structure of, 319

absorption, 251

adventitious, 301

aerial, 306

assimilation, 306

belladonna, cross- section
of, 318

branches, 319

breathing, 306

cap, 299, 301

climber, 324

contraction of, 319 ;

hairs, 299, 301, 309

inner structure of, 309

lateral, 301, 312

modified, 306

outer morphology of, 299

phytolacca, cross-section
of, 318

pressure, 252

primary, 301

structure of dicotyle-
dons, 345

primordia, 301

secondary, 301

stele, 313

stock, 325

tap, 301

true, 299

tubercle, 306

tuberous, 305, 327
Roripa, 553
Rosa, 457, 564
Rosaceae, 560
Resales, 556
Rose, 457, 564

apple, 632

bay, 457, 647

camphor, 564

family, 560

geranium, 579

Rose, hip, 409

oil, 564

petals, 564

tea, 629

wood, 544
Rosemary, 457
Roseus-a-um, 457
Rosin, weed, 459, 723
Rosmarinus, 457, 676
Rostratus-a-um, 458
Rotate, 388
Rottlerin, 180, 592
Rotundifolius-a-um, 458
Rubber, India, 241, 592

trees, ,241
Ruberithrinic, 169
Ruber-ra-rum, 458
Rubia, 702
Rubiaceae, 697
Rubiales, 697
Rubus, 458, 563

cork in, 293

fruit, 416
Rudbeckia, 723
Rue, 458

anemone, 535

family, 581

garden, 585

meadow, 460
Ruellia, 694
Rugose, 354
Rugosus-a-um, 458
Rum, bay, 632
Rumex, 458, 523
Runner, 325
Rush, 458

bog, 449

family, 493

matting, 493

scouring, 96

soft, 493

spike. 444

wood, 493
Rust, wheat, 69
Ruta, 458
Rutaceas, 581
Rutin, 170, 585
Rye, 458, 467

lecithin in, 214

protein in, 199

starch in, 148

sugar in, 157

Sabadilla, 458
Sabal, 458, 473
Sabbatia,-664
Sabina, 115, 458
Sable tetraedrique, 188
Sabodilla tree, 659
Sac, pollen, 120
Saccate, 388
Saccharomyces, 47
Saccharomycetes, 47
Saccharose, 154, 155
Saccharum, 458, 467

INDEX.

801

Sacci, 492
Safflower, 387, 719

oil in, 213

yellow, 720
Saffron, 442, 493

meadow, 442
Safranin, as staining agent,

757
Sage, 458

garden, 676

hairs of, 284
Sageretia, 606
Sagittaria, 465
Sago, 475

palms, 475

starch, 475
Sagrada, 440
Saigonicus-a-um, 458
Salegenin, 700
Salicaceae, 508
Salicales, 508
Salicin, 169, 170, 508
Salicylic aldehyde, 564
Salix, 458, 508

tannin in, 206
Salsify, 461

Salt, table, source of, 556
Salvia, 458, 676

hairs of, 230, 285
Samadera, 586
Samara, 420, 510, 602
Sambucus, 458, 706

cork in, 293
Sambunigrin, 169
Sanctus-a-um, 458
Sandal, oil, 518

tree, 458

wood, 458

family. 518
Sandarac, 119
Sand-box tree, 592
Sanguinaria, 458, 548, 550

latex, 241
Sanicula, 458
Santal, bastard, 581

oil, Chinese, 519
Santalaceae, 518
Santales, 518
Santalinus-a-um, 458
Santalol, 519
Santalum, 458, 518
Santonin, 719
Sap, ascent of, 252

cell, 134

Sapindacea?, 602
Sapindales, 594
Sapindus, 603
Sapium, 594
Sapodilla family, 658
Saponaria, 172, 458, 53O,

531

Saponarin, 169
Saponin, 171, 575, 603, 611

occurrence of, 172
Sapotaceae, 658

Sapotilla, 659
Sapotoxin, 170
Sappan, 439
Saprolegnia, 42
Saprophytes, 40
Sapucaya nut, 629
Sarcocarp, 40, 410
Sarcophyte, 519
Sargassum, 31
Sarracenia,36i, 458, 554,555
Sarraceniaceas, 554
Sarraceniales, 554
Sarracenine, 554
Sarsaparilla, 487

wild, 637
Sassafras, 458, 544

mucilage in, 263

oil, 544

Sativus-a-um, 458
Satureia, 679
Savin, 119

Savory, summer, 679
Saxifragaceae, 556
Saxifrage family, 556

golden, 441, 556, 557
Scabiosa, 708
Scadens, 458
Scale, seminiferous, 108
Scammonia, 458
Scammony, 458

root, 669

Scarlet sumac, 597
Scatol, 519
Schinopsis, 599

tannin in, 206
Schizandra, 540
Schizogenous, 226
Schizo-lysigenous, 226
Schizomycetes, 12
Schizophyceae, 8
Schizophytes. 7
Schulze's cellulose reagent,
760

macerating solution, 761
Scilla. 458
Scillain, 170
Scirpus, 458, 472
Scitamineae, 493
Scitaminales, 493
Scleranthus, 531
Sclerenchyma, 266
Sclerenchymatous fibers, 268
Sclerocarya, 599
Sclerotium, 52
Scolopendrium, 458
Scoparia, 458
Scopolia. 684

fruit, 412

tracheae in, 274
Scopolin, 170
Scotch broom, 569
Scrophularia, 691
Scrophulariaceae, 688
Scullion, 485
Scurvy grass. 553

Scutellaria, 384, 458, 673
Scytonema, 72
Sea bean, 575

Island cotton, 610 '

lettuce, 25

weed, 435

protein in, 200
Secale, 458, 467
Secondary corter., 312, 313

roots, 301

structure, 313

of stems, summary, 345
summary, 317
Secretory canals, 228

cavities, 227

cavity in pines, 107

cells, 226
Sections, 749

making of, 749
Sedge, 439, 472
Sedum, 458, 556

purpurascens, 368
Seed, 379

development of, 125

dispersal, 427

inner structure of, 427

outer morphology of, 423

pans, 729

plants grown from, 728

structure of, 424
Selaginella, 86, 98-10^
Semecarpus, 458
Sempervirens, 459
Sempervivum, 556
Seneca root, 459
Senecio, 459
Senega, 459, 589

Texas, 589

white, 589
Senegal, 459
Senna, 440, 459, 567

Alexandria, 567

American, 360

hairs of, 285

India, 567

Tinnevelly, 367

Tripoli, 567
Sepals, 120, 374, 382
Septa, 411
Septicidal, 411
Septifragal, 411
Sequoia, 117 .
Serenra, 459, 473
Sericeous, 354
Serotin, 169
Serotinus-a-um, 459
Serpentaria, 459, 520

Southern, 521
Serrate, 356
Serrulatus-a-um, 459
Sesame, 459

oil in, 213, 691
Sesamum, 459, 691
Seudo tanga, 119
Seven barks, 556

802

INDEX.

Sexual generation, 298

spore, 298
Shaddock, 584
Shea butter, 212, 659
Sheep laurel, 648

sorrel, 524

Shepherd's purse, 439, 554
Shield fern, 437
Shikimi, 540
Shoot, 299

aerial, 329

axis, 299

creeping, 304

epigeous, 321, 322

hypogeous, 321, 325

overground, 321

subterranean, 329

underground, 321

undeveloped, 321
Shorea, 621
Shoyu, 577
Shrubs, 329
Sida, 611
Siejas, 519

Sierra Leone copal, 574
Sieve, 276
Sigillaria, 100
Silene, hairs in, 282
Silica, 202

forms of, 1 88
Silique, 420, 459
Silk, 269

dye, 625
Silk weed, 437
Silkworm, food, 517
Silphium, 723
Silver-leaf poplar, 508
Simaba, 459
Simaruba, 586
Simarubacese, 585
Simple leaf, 348
Sinalbin, 169, 170
Sinapis, 459, 553

germination of, 299
Sindor balsam, 621
Sinensis-e, 459
Sinigrin, 169, 170
Sinuate, 356
Sisal fiber, 269
Sisymbrium, 459, 553
Skullcap, 458, 673
Skunk cabbage, 478, 480
Sleep movements, 361
Slime molds, 2
Sloanea, 609
Small nettle, 517

Solomon's seal, 483
Smartweed, 448
Smilacina, 484
Smilax, 459, 485

species of, 487
Smut, 461

corn, 67
Snakehead, 441
Snakeroot, 459

Snakeroot, black, 458, 532

Canada, 520

Virginia, 520
Sneeze-weed, 447, 723
Snow-ball, 705
Snow berry, 460, 707
Soap bark, 564, 565

berry family, 602

plants, 171
Soapwort, 458, 520
Socotrinus-a-um, 459
Soda, plants yielding, 530
Sodium in seaweeds, 28
Soft galls, 334
Soil acidity, 249

bacterium, 307

organic constituents of,

250

Soja beans, 199
Solanaceae, 683

flowers of, 385
Solanidine, 688
Solanine, 172, 684
Solanum, 385, 459, 684

fruit, 412

Solidago, 459, 521, 722, 726
Solomon's seal, 456
Solution, Beale's carmine,
760

Bohmer's haematoxylin,
760

chloral-iodine, 761

chlor-zinc-iodine, 760

copper acetate, 761

Delafield's haematoxylin,
760

Grenadier's borax-car-
mine, 760

Grenacher's haematoxy-
lin, 760

Hoyer's picro-carmine,76o

iodine and potassium io-
dide, 761

iron, 761

phloroglucin, 761

Schulze's macerating, 761
Somnifer-a-um, 459
Sorbile, 459
Sorbilis-e, 459
Sorbit, 563
Sorbus, 459, 562
Sorghum, 459, 467

juice, percentage of sugar

in, 157
Sorosis, 420
Sorrel, field, 524

sheep, 524, 525
Southernwood, 434
Soy, 577
Spadix, 394. 475
Spanish licorice, 568

moss, 481
Sparganiaceae, 463
Sparganium, 464
Spathe, 394, 478

Spathiflorae, 475

Spawn, 56

Spearmint, 384, 676, 678

plant of, 326
Special reagents, 755, 761
Specimens, mounting of, 762
Spectroscope, 764, 765
Speedwell, 462
Sperm, 5

Spermophytes, 100
Sphaerites, 192, 678
Sphasrobacteria, 13
Sphagnum, 84, 85
Sphere crystals, 678
Spicatus-a-um, 459
Spice bush, 439, 544
Spider wort, 461, 480
Spigelia, 459, 661

tracheae of, 274
Spignel, 452
Spike, 394

oil, 679

Spikelet, 394, 469
Spikenard, 453
Spilanthes, 724
Spilanthin, 724
Spinach, 527

protein in, 199

sugar in, 157
Spinacia, 527
Spindle tree, 445
Spinose, 354
Spiraea, 459, 564
Spiral, thickening, develop-
ment of, 272
Spirogyra, 18
Spleenwort, 437
Sporangia, 375
Sporangium, 4
Spores, 3

asexual, 4, 298

sexual, 4, 298

staining of, 71

swarm, 5
Sporidia, 66
Sporobolus, 467
Sporogonium, 79
Sporophylls, 375
Sporophyte, 75

embryo, 298
Spring beauty, 531
Spruce, 109, 455

beer, 119

black, 112

Douglas, 114

Norway, 119

pine, 112

white, tannin in, 206
Spurge, 445, 500, 590
Squarrosus-a-um, 459
Squash, 443
Squaw-root, 695, 696
Squaw weed, 459
Squill, 458, 461, 487
Staff tree, 440, 600

INDEX.

803

Stage micrometer, 754
Staining agents, 757

of bacteria, 16

double, 762
Stains, 755
Stalk, 348
Stamen, 120, 374, 375, 379

different types of, 380
Staminate, 392
Staminodia, 391
Staminodes, 391
Staphisagria, 459, 535
Star apple, 659

grass, 435

of Bethlehem, 485
Starch, 140, 435

assimilation, 140

botanical distribution of,
147

Brazilian arrow-root, 670

characteristics of, 145

grain, composition of, 143
development of, 141
structure of, 143

manufacture of, 148

occurrence of, 143

percentage of, 148

properties of, 145

reserve, 137, 143

seen with the micropolari-
scope, 146

sweet-potato, 670

with iodine, 147
Stavesacre, 459, 535
Stem, 299, 320

branches, 320

inner structure of, 338

of dicotyledons, 338

outer morphology of, 320

primary structure of, 338

structure, abnormal, 344
dicotyledonous, 339
primary, summary, 345
secondary, summary,
345

underground, 325
Sterculia, 615

seeds, 615
Sterculiaceae, 612
Sterilization, 15
Stick-lac, 238
Sticta, 73
Stigma. 120, 376, 378

different types of, 377

epithel. 406

structure of, 405
Stillingia, 459, 590
Stinck weed, 460
Stinging nettle, 517
Stink-wood, 546
Stipa, 472
Stipe of fungi, 57
Stipules, 348

function of, 348
Stitch-wort, 531

St. John's bread, 440, 576

wort, 448

family, 620
Stolon, 325
Stoma, 279
Stomata, 278, 367, 368

on leaves of Beta, 367
Stonecrop, 458

common mossy, 556

ditch, 556

Virginia, 556
Stoneworts, 26
Storax, 460, 559, 660
Stramonium, 460, 684

fruit, 409, 412

hairs of, 284

seed, 428

tr.ansverse section of mid-
rib, 366
Strawberry, 445, 566

fruit, 409, 415

garden, 566

protein in, 200

wild, 567

Striatus-a-um, 460
Strigose, 354
String beans, 199
Strobile, 375, 420
Strobiles, 375

Strophanthin, 169, 170, 171
Strophanthus, 460, 666

haiis of, 284, 285
Strophiole, 427
Structure, basis of, I

of wood, 347

primary, 254, 309
summary, 317

secondary, 254
summary, 319

stem, classification of,

341

primary, summary, 345
Strychnine crystals, 769
Strychnos, 460, 661
Stryphnodendron polyphyl-

lum, tannin in, 206
Style, 120, 376, 378

structure of, 406
Styloids. 183
Stylophorine, 550
Stylophorium, 550
Styracaceae, 660
Styraciflua, 460
Styrax, 460, 558, 660
Suberin, 257, 290
Suberose, 257
Sublimable principles, 173
Succisa, 708
Succory, 441, 716
Sucrose, 155, 527
Sugar, 154

beet, 52?

protein in, 199

bush, 518

cane, 467

Sugar.cane.juice.percentage
of sugar in, 157

in cereals, percentage of,
156

in plants, 156

in vegetables, 156
Sumach, 457, 595

poison, 597

scarlet, 597

tanner's, 595
Sumbul, 639
Summer savory, 679
Sundew, 361 444, 554
Sun-dial, 451
Sun-flower, 712

oil in, 213

seed-cake, 725

seed, protein in, 199
Sun's energy, 138
Suppressed, 391
Surface of leaves, 353
Suringi, India, 620
Survival of the fittest, 131
Suspensor, 125
Suture, dorsal, 377

ventral, 377
Swamp pink, 485, 490
Sweet, 444

almond, protein in, 199

anise oil, 643

balm, 679

basil, 679

cicely, 643

fern, 509

flag, 479

gale, 509

gum tree, 450, 558

marjoram, 679

pea, 576

potatoes, protein in, 199
percentage of sugar in,

157

starch, 670
vine, 669

scabious fleabane, 713

William, 531

wine, 607
Swertia, 460, 664
Swietenia, 589
Sycamore, 559
Syconium, 420
Sylvaticus-a-um, 460
Sylvestris-e, 460
Symmetrical, flower, 392
Sympetalae, 643
Sympetalous, 385
Symphonia, 620
Symphoricarpos, 460, 707
Symphytum, 460, 671
Symplocarpus, 478, 480
Synantherin, 150, 726
Syncarpous, 376
Synergids, 124
Syngenesious, 382
Synura, n

INDEX.

Syringa, 455, 460, 661
Syringin, 169, 661
Syringopicrin, 661

Tabacum, 460

Table salt, source of, 556

Tacamahac, 439, 508, 613

Bourbon, 618

Brazilian, 618

India, 618

resins, 587

West Indian, 587
Tagetes, hairs in, 288
Talauma, 540
Tallow tree, Chinese, 594
Tamaricaceae, 621
Tamarindus, 460, 569
Tamarix, 621
Tamonea, 634
Tamus, 492, 709
Tanacetum, 460, 720
Tangential-longitudinal sec-
tion, 749
Tangkawang, 621
Tanner's sumac, 595
Tannides, 202
Tannin, 202

chemical properties of, 203

distribution of, 205

idioblast, 207, 208

in galls, 335

micro-chemistry of, 204

pathological, 207

physiological, 207
Tannol resins, 236
Tansy, 460, 720
Tapetum, 121
Tapioca starch, 594
Tap-root, 301
Tapura, 606

Taraktogenos kurzii, 214
Taraxacum, 239, 387, 460
Taxus, 113
Tea, 460, 617

Appalachian, 600

black, 618

Brazilian, 600

caffeine in, 162

cassine, 600

chests, 625

culture, 746

family, 617

green, 618

Labrador, 450

New Jersey, 605

Paraguay, 600

germination of, 730

plant, 615

rose, 629

seed, oil in, 213

substitute, 53 j, 634

tree, 617
Teaberry, 650
Teak-tree, .673
Teak-wood, 673

Teasel, 444, 707
Technique, bacteriological,

14

Tecoma, 691
Tectona, 673
Tegmen, 425
Telegraph plant, 361
Teleutospores, 68
Temperature, 247
Tendril, 323

climber, 324
Tephrosia, 575
Terebinthina, 460
Terminalia, 633
Terpenes, 233
Terpinene, 679
Terpineol, 632
Terra silicea purificata, 38
Testa, 425

Testing of drugs, 248
Tetradynamous, 381
Tetragonal crystals, 183
Tetrameles, 625
Tetrapanax, 636
Teucrium, 460
Texture of leaves, 354
Thalictroides, 460
Thalictrum, 460
Thallophytes, 6
Thallus, 6
Thea, 460, 616
Theaceae, 617
Thein, 173, 176
Thelephoraceae, 59
Theobroma, 460, 612
Theobromine, 612, 618
Theophylline, 618
Thistle, 712, 723

blessed, 442

milk, 451.

star, 440

Virgin Mary's, 451
Thlaspi, 553
Thorn apple,, 684
Thorough wort, 445, 712
Thuja, 1 1 8, 460
Thujone, 719
Thyme, 460

field, 441

garden, 677
Thymelaea, 628
Thymelaeaceae, 627
Thymol, 234, 678, 681
Thymo-quinhydrone, 179
Thymoquinone, 179, 681
Thymus, 460
Tiarella, 460, 556
Tibouchina, 634
Tick Trefoil, 443
Tilia, 461, 608, 609

hesperidin in, 153

species of, 609
Tiliaceae, 609
Tillandsia, 480
Tinctorium, 460

Tinctorius-a-um, 460
Tissue, 121

conjunctive, 313

laticiferous, 296

mechanical, 264

milk, 296
Tobacco, 453, 460, 688

camphor, 688

Indian, 710

Persian, 688

plant, Virginia, 688

Turkey, 688

wild, 710
Tococa, 634
Toddy, 620
Tolu, balsam of, 572
Tolu-resinotannol, 572
Toluifera, 461, 572
Tomato plant, 688

sugar in, 157
Tomentose, 354
Tomentosus-a-um, 461
Toothed, 385
Toringin, 562
Tormentilla, 565
Torus, 375, 389
Touch-me-not, 448
Touranose, 155
Tous les mois, 496
Toxalbumins, 196, 726
Toxicodendrol, 595
Toxicodendron, 461
Toxylon, 516
Tracheae, 273, 313

markings of, 273
Tracheids, 275
Trachylobium, 574
Tradescantia, 461, 480
Tragacanth, 218, 461, 569,

570
Tragopogon, 461

hairs in, 288
Trailing mahonia, 537
Transpiration, 350
Transverse heliotropism, 349

section, 749
Trapa, 634
Treacle mustard, 553
Tree of heaven, 434
Trees, 329

green coating on, 21
Trefoil, clover, 461

bird's foot, 450
Trehalose, 155
Tremellaceae, 59
Triandrus-a-um, 461
Triassic period, 101
Trichodesmium, 8
Tricolor, 461
Tricuspidatus-a-um, 461
Trifolium, 461, 576
Trilisa, 461
Trillium, 461
Trimorphic flowers, 399
Triosteine, 707

INDEX.

805

Triosteum, 706

Umbelliflorae, 636

Triphyllus-a-um, 461

Umbellularia, 461, 544

Tristichous, 363

Umbrella tree, 540

Triticum, 461, 467, 468

Unguis, 385

Trivial, 461

Unifacial leaf, 366

Trivialis-e, 461

Uniflorus-a-um, 461

Tropagolaceae, 579

Unisexual, 444

Tropaeolum, 579

flower, 392

True root, 299

Unona, 542

Solomon's seal, 483

Upas-tree, 516

Truffles, 65

Uragoga, 699, 7OO

Trumpet-creeper, 691

Urari poison, 51?

Truncate, 355

Urceolate, 388

Tsuga, 113, 118, 461

Uredineae, 65

Tuber, 326

Uredospores, 69

Tubercle, root, 306

Urena, 611

Tuberin, 195

Urginea, 461, 487

Tuberose, 485

Uroglena, 8, 10

Tuberosus-a-um, 461

Urtica, 461, 517

Tubiflorae, 668

Urticaceae, 51?

Tubular flowers, 711

Urticales, 512

Tuckahoe, 65

Use and disuse, 131

Tulip, 485

Usitatissimus-a-um, 461

bulb, 330

Usnea, 73

tree, 450, 539

Ustilagineae, 65

Tupelo, 453, 518

Ustilago, 67. 461

Turner ic, 494

Utricle, 420, 527

Turmerol, 496

Utricularia, 299

Turnera, 623

Uva-ursi, 461, 644

Turneraceae, 623

Uvularia, 485

Turnip, 438, 553

Indian, 436

Vaccinium, 174, 653

little, 453

fruit, 417

protein in, 199

Vacuole, 134

sugar in, 157

Valerian, 462, 707'

Turpentine, 118, 460

garden, 707

as a clearing agent, 757

Greek, 671

Canada, 118

wild, 707

Strassburg, 119

Valeriana, 462, 707

Venice, 118

Valerianaceae, 707

Turpeth, 461

Valerianales, 707

root. 453

Valerianella, 7.07

Turpethum, 461

Vallea, 608

Turtlehead, 441, 691

Valonia, tannin in, 206

Tussilago, 387, 461, 723

Valvate, 389

Twin leaf, 449

Vanilla, 462, 497

Twiner, 324

grass, 472

Types of mestome strands,

hairs of, 284

343

leaf, 461

Typhaceae, 463

sugar in, 157

Vanillin, 173, 572

Ulex. 575

Variifolius-a-um, 462

Ulfnaceae, 512

Various woods, coarse struc

Ulmaria, 461

tures of, 346

Ulmus, 461

Varnish tree, 597

section of wood, 346

Vasicine, 696

species of, 512

Vateria, 621

Ultra-microscope, 765

Vatica, 621

Ulva, 25

Vaucheria, 22, 40

Umbel, 394. 636

Vegetable agglutinins, 198

Umbellales. 636

bezoars, 577

Umbellated, 461

butter, 659

Umbellatus-a-um, 461

ivory, 473, 474

Umbelliferae, 575, 636

Vegetative organ, 299

fruit of, 417

Veins, 352

Venation in Dicotyledons, 353

Monocotyledons, 352
leaf, 352

Venenosus-a-um, 462
Ventral palisade tissue, 366

suture, 377

Venus's fly-trap, 362, 554
Veratrum, 462, 485

section of root, 320
Verbain, blue, 674
Verbascum, 691
hairs of, 286
hesperidin in, 153
Verbenaceas, 673
Verbenas, 673, 674
Vermilion, 597
Vernation, 364
Veronica, 462, 689
Verrucose, 354
Versatile, 380
Versicolor, 462
Verticillatus-a-um, 462
Verus-a-um, 462
Vervain, 673

nettle-leaves, 673
Vessels, 273, 313
Vetchling, 450
Viburnum, 462, 704, 705
Vicia faba, 199
Vicianin, 169
Vicilin, 195
Victoralis, 462
Victoria, 532
Vignin, 195
Villosus-a-um, 462
Vinca, 668
Vinifer-ra-rum, 462
Viola, 462, 622

glandular hairs in, 230
leaf of, 348
quercitin, 622
stem in section, 336
stomata in, 278
structure of flower, 403
Violaceae, 622
Violet, 462

dog's tooth, 485
English, 622
family, 622
leaf of, 348
sweet, 622
Virginia creeper, 607

grape-fern, 365
Virginianus-a-um, 462
Virginicus-a-um, 462
Viridiflorus-a-um, 462
Viridis-e, 462
Virosus-a-um, 462
Viscine, 518
Viscum, 518
Vismia, 619. 620
Vitaceae. 606
Vitae, arbor, 460
Vitis, 462, 607
Vittae. 637

8o6

INDEX.

Volvox, 21

White clover, colors, 178

Vouacapoua, 436, 462

wines, 607

Vulgaris-e, 462

Whortleberry, 654

Wild black cherry, 560

Wahoo, 600

brier, 564

Wake-robin, 437, 461

caper, 591

Walking leaf, 439

cherry, 561

Wall, composition of, 254

indigo, 573

kinds of, 258

marjoram, 679

marking of, 260

strawberry, 566

mucilage, 257

yam root, 492

origin of, 254

Willow, 458, 508

pepper, 556

herb, 440, 634

thickening of, 260

flowers, 400

Walnut, 449, 509

Wind flower, 436

black, 509

Wine, 607

English, cross-section of

light colored, 607

wood, 346

mammey, 620

family, 509

port, 607

oil in, 213

red, 607

white, 509

sweet, 607

Waltheria, 615

white, 607

Wandering Jew, 480

Winterana, 622

Washingtonia, 643

Winteranaceae, 622

Water, 247

Winter cress, 438

arum, 439, 479

Wintergreen, 644, 650

cress, 553

Winterin, 540 .

fennel oil, 643

Winter's bark, 540

hemlock, 575, 642

Wistarin, 575

iodine, 761

Wisteria, 462, 575

leaf family, 670

Witch-hazel, 447, 558, 559

lily family, 531

Witch's brooms, 334

melon, 710

Wolfsbane, 434

net, 22

Wood, 317

plantain, 466

bass, 461

pores, 279 '

carving, 117

Wax, 210, 216, 277

fibers, 270

carnauba, 2, 4

in coal, up

crystalline, 216

pulp, 117

forms of, 216

red, 117

Japan, 212,

rush, 493

myrtle, 211, 212, 509

sorrel, 454, 544, 579

ocotilla, 621

structure of, 346

opium, 214

Woodfordia, 628

Wheat, 461, 467

Woodruff weed, 437

grass, 434

Wool, 269

lecithin in, 214

Woolly, 354

protein in, 199

Wormseed, 527

starch in, 148

Spanish, 527

sugar in, 15?

Wormwood, 434, 437, 719

White clover, 472

hairs of, 285

Xanthium, 462, 723
Xanthone, 180
Xanthorhamnin, 169, 170
Xanthosome, 480
Xanthostrumarin, 723
Xanthoxylum, 462, 582
Xerase, 49
Xylem, 312
Xylopia, 541, 542
Xylose, 169
Xyrideales, 480

Yam, 444, 492

root, wild, 322, 492
Yarrow, 434, 452
Yeast, 47

dry, lecithin in, 214

glycogen in, 154
Yellow gum, 574

pond lily, 434, 531
Yerba Mate, 60 1

Santa, 670
Yew, 113
Ylang-ylang, 542
Yohimbi bark, 702
Yohimbihi bark, 702
Yohimbine, 702
Yucca, 485

Zanthoxylum, 581, 582
Zanzibar copal, 574
Zea, 462, 467, 469

root-tip, 300
Zeora, 75
Zeridine, 49
Zeylonicus-a-um, 462
Ziehl's carbol-fuchsin, 757
Zingiber, 462, 494, 495
Zingiberaceae, 494
Zizyphus, 606
Zollikoferia, hairs in, 282
Zoo-cecidien, 335
Zoospores, 5
Zostera, 466
Zygadenus, 574
Zygomorphic, 393
Zygomycetes, 42
Zygophyllaceae, 581
Zygospore, 5
Zymase, 244

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IfclllKNW 10

WOIOGY

LJ)2lA-6m-9,'73
(R2491slO)476-A-32

General Library .
University of California
Berkeley