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A MANUAL
STRUCTURAL BOTANY
AN INTEODUCTOEY TEXT-BOOK FOR STUDENTS
OF SCIENCE AND PHARMACY
^ /
BY
HENRY H. RUSBY, M.D.
PROFESSOR OF MATERIA MEDICA IN THE COLLEGE OF PHARMACY OF THE CITY OF NEW YORK (COLr.MBI^
university) ; chairman op the scientific DIRECTORS OF THE NEW YORK BOTANICAL
gardens; president of the TORREY BOTANICAL CLUB; PHARMACOGNOSIST
OF THE UNITED STATES DEPARTMENT OF AGRICULTURE; MEMBER
OF THE COMMITTEE FOR THE REVISION OF THE UNITED
STATES PHARMACOPOEIA SINCE 1890
WITH 599 ILLUSTRATIONS
LEA & FEBIGER
PHILADELPHIA AND NEW YORK
1911
Entered according to the Act of Congress, in the year 1911, by
LEA & FEBIGER,
in the Office of the Librarian of Congress. All rights reserved.
PREFACE
This volume, which is a condensed but fairly complete introduction
to botany, and is suitable as a text-book for academic or collegiate
students, has been written with special reference to the needs of the
first year student of pharmacy, as a preparation for his second year
work in pharmacognosy. It may, therefore, be regarded as an intro-
duction to pharmacognosy, as well as to general botany. It will be
followed by a companion volume on Commercial Pharmacognosy.
Pharmacognosy may be defined as the art of identifying, valuing,
and selecting drugs of vegetable and animal origin. It is, therefore,
^not a distinct science, although various sciences may be employed in
its practice. In such operations as taking specific gravity, making
microscopical measurements and determining the characters of crystals,
physics is utilized. In making qualitative tests of identity and purity
and determining the percentages of constituents, chemistry is involved.
In determining the structural characters of plant and animal bodies,
botanical and zoological knowledge is necessary. In determining the
value of drugs of which the purity and strength cannot be estimated
by any of these methods, we may have recourse to physiological tests
on animals, or pharmaco-dynamics.
It is thus apparent that the entire field of pharmacognosy is very
broad and that its complete working involves varied classes of labora-
tory operations. The extent and complexity of detail that have
become necessary in these operations have required their consideration
in separate departments of the pharmaceutical curriculum, so that such
branches as physical and chemical testing and pharmaceutical assaying
have been established.
The number of drugs of animal origin in general use has become so
small that the study of zoology is no longer deemed essential, and it is
left to botany to contribute by far the greater portion of the instruction
now deemed essential as a preparation for the study of pharmacognosy.
Manifestly, a knowledge of structural botany is the only scientific
basis for the examination of the i)lant body.
VI PREFACE
Since a correct knowledge of the structural relations of the plant-
parts to one another can scarcely be gained without some knowledge
of their uses in the economy of the plant, it follows that at least the
elementary facts of plant-physiology must be considered in connection
with its anatomy.
The parts of plants which are used as drugs may come to us either
in their entire condition or in such large fragments as to be capable
of examination with the naked eye, or in the crushed or powdered
condition, when their examination requires the aid of the compound
microscope. Even in the case of the whole drug, the examination will
frequently call for the aid of the microscope in determining difficult
questions of identity or quality.
Commercial Pharmacognosy may be defined as the application of
pharmacognosy to ordinary commercial operations. It includes the
examination of crude drugs by growers, collectors, traders, brokers,
importers, and ordinary purchasers for pharmaceutical purposes.
All such persons should be qualified to subject their drugs to the
most complete and minute examination, or should employ someone
who is so qualified; but, as a matter of fact, this is probably not
true in more than one case in a hundred, though happily this propor-
tion is steadily increasing. In all others, dependence is wholly upon
examinations made with the naked eye, or at most with a pocket lens.
The work on Commercial Pharmacognos}" will be designed for the use
of all such persons in their commercial operations with drugs. It will
deal with the commercial aspects of all drugs found in commerce, their
identity, varieties, grades, and qualities, their substitutes, adulterants,
and imperfections, their trade designations and relative values.
Although designed for use as a text-book, it will be especially valuable
in its commercial adaptations.
In view of the totally different methods of examination involved,
and the apparatus and other facilities required, the subjects of
vegetable histology and of microscopical methods and technique are
omitted from the present work, its object being to teach the student
all that it is possible for him to do in the examination of drugs with
the naked eye or with the pocket lens.
H. H. R.
CONTENTS
CHAPTER I
Fundamental Considerations 17
CHAPTER II
Anthology; General Nature of the Flower 23
CHAPTER III
Laws of Floral Structure 36
CHAPTER IV
The Perigone 50
CHAPTER V
The Androecium 62
CHAPTER VI
The Gynaecium 70
CHAPTER VII
The Torus and Disk 81
CHAPTER VIII
Dissection and Analysis of Flowers 86
CHAPTER IX
Pollination and Fertilization 90
CHAPTER X
Carpology; Functions and Structure of the Fruit 102
CHAPTER XI
Classification of Fruits 116
Vlll CONTENTS
CHAPTER XII
The Seed 127
CHAPTER XIII
General Structure of Root andStem . 136
CHAPTER XIV
Extensions and Appendages of the Stem 15;j
CHAPTER XV
Classification OF Roots AND Stems 158
CHAPTER XVI
The Leaf 170
CHAPTER XVII
Anthotaxy 199
CHAPTER XVIII
Cryptogams 207
CHAPTER XIX
Botanical Classification and Analysis 21 S
CHAPTER XX
Botanical Nomenclature 222
CHAPTER XXI
The Collection and Preservation of Botanical Specimens .... 226
INTRODUCTION TO PHARMACOGNOSY.
STRUCTURAL AND DESCRIPTIVE BOTANY
CHAPTER I
FUNDAMENTAL CONSIDERATIONS
Organic Bodies, Organs and Functions. — Living bodies differ from
those wliich are lifeless in their al)ility to grow by converting into their
own substance extraneous and dissimilar substances, as seen in the use
of carbonic acid in the ]:)roduction of starch and cellulose. This process
is called Assimilation. They consist also of more or less distinct parts,
each of which performs special work differing from that performed by
the other parts. These parts are called Organs or ]\Iembers, and the
special work which each organ performs is called its Function. Living
bodies are, therefore, designated as Organic Bodies and the part of
nature composed of them the Organic Kingdom. The term "organic
body" is usually preferable to "living body," as it applies equally well
to a body in which life has ceased to exist. A third important char-
acteristic of living bodies which may be mentioned is their power to give
origin to other independent living bodies, which, separating from their
parent, or remaining attached thereto, grow into a resemblance to it.
That is, they possess the power of Reproduction.
Organic Matter. — The assimilated matter of organic bodies is called
Organic Matter. Organic matter may be living, as cytoplasm, or lifeless,
as starch. It may, as in the case p/ the starch, be prepared for future
use as food, or be for the construction of tissue, as in the case of cellu-
lose, or it may exist as disassimilated matter resulting from the per-
formance of function, as the poisonous ptomaines of bacteria. The
latter may still be of some service in the i)lant economy, as are volatile
oils, or, perhaps, be entirely useless.
Plants and Animals. — Organic bodies are of two kinds — ^\>getable
and Animal — and are respectively denominated Plants and Animals.
Biology. — The study of the organic kingdom constitutes Biology.
Anatomy. — Biology in attention to the structure of bodies is Anatom}'.
f ROPERTT UBRAIf
r. ir
18 FUNDAMENTAL CONSIDERATIONS
Physiology. — Biology in attention to functions is Physiology. We
have therefore both animal and plant anatomy, and animal and plant
physiology.
Botany. — Biology relating to plants is Botany.
Gross and Minute Anatomy. — Owing to the totally different methods
of examination employed in the two cases, it becomes of the greatest
convenience to divide anatomy, in practice, into two parts. That part
depending upon observations which can be pursued without the aid of
the compound microscope is knowai as Gross Anatomy. That which
requires such aid is Minute Anatomy, or Histology.
Microscopical Botany. — Applied to botany, the latter is commonly
known as Microscopical Botany, a term which, though incongruous,
possesses the excellent merit of being highly convenient and generally
expressive.
As the study of botany involves the use of physics and chemistry*
it is apparent that when so applied they become parts of botany, just
as botany becomes a part of physics or chemistry when applied in the
pursuit of those branches. The propriety of such terms as "chemical
botany" or "botanical chemistry" is thus explained.
Departments of Botany. — The departments of botany, and the manner
in which one may arise from the necessities of another and contribute
to it, may be illustrated as follows:
Systematic Botany. — It being understood that no plants are now in
existence which existed in the beginning, all having originated through
changes effected in some manner in those which formerly existed, one
of the great objects of botanical study is to ascertain the genetic rela-
tionships which exist between plants and to constitute such a systematic
arrangement of them as shall, so far as practicable, indicate the lines
and order of their development from others, that is, of their Phylogeny,
This department constitutes Systematic Botany.
Structural Botany. — Since such classification is based chiefly upon
structure, it is necessary that there should be a department known as
Structural Botany.
Physiological Botany. — Before the facts ascertained by the struc-
tural botanist can be utilized in classification, it is necessary that the
relative ranks of the structural characteristics should be determined.
Of any two structural characteristics, that which was first developed,
or is the older in creation, should form the basis of the primary division
of the group, the other of a subdivision. In ascertaining such relative
ranks, a consideration of the uses of the several characters is of great
MEDICAL BOTANY 19
value, so that Physiological Botany or AVgetable Physiology is brought
into service.
Organography. — When structural botany has for its object merely the
determination of the organs as they exist, it becomes Organography.
Organogeny or Morphology. — When such object is to determine the
development of organs through the transformations of others, as of a
petal from a leaf, or a tendril from a branch, it becomes Organogeny or
Morphology.
Homologies and Analogies. — The ancestral organ and its developed
product are called Homologues of each other, and an Homology or
Affinity is said to exist between them. For example, the leaf of a plant,
and the petal of its flower, which we assume to have developed through
the modification of the leaf, are homologues of one another. When they
are only similar, without any genetic relationship, they are Analogues
of each other, and Analogy exists between them. Morphology might,
therefore, be defined as the stud}^ of homologies.
Anthology and Carpology. — As classification has been based very
largely upon flower structure and fruit structure, the study of these,
respectively, has been dignified by the titles Anthology and Carpology.
Phytography. — The description of plants in such manner that they
can be recognized therefrom is called Descriptive Botany or Phytog-
raphy.
Other Departments. — Botany has also numerous departments depend-
ing upon the class of plants under study, as Phanerogamic Botany, the
botany of flowering plants; Cryptogamic Botany, that of flowerless
plants; Mycology, the study of fungi; Agrostology, the stud}' of grasses.
Agricultural Botany. — This is subdivided into a number of different
departments, such as Agrostology, or Graminology, the study of grasses
and of their culture; Horticulture, the study of garden plants and of
their culture; Floriculture, Pomology, and Forestry. Doubtless a ver\'
large and important department will yet be established for the study
of the culture of medicinal plants.
Medical Botany. — This term is self-explanatory as to its general
nature. In use, however, it should be more strictly regarded than is
customary. The term originally included all botany relating to medi-
cinal plants; but with the development of Pharmacy the greater portion
of what was once comprised in the former term has naturally and per-
manently established itself in the form of the separate department,
Pharmaceutical Botany. Medical Botany properly concerns itself with
the medicinal properties and active principles of plants, and the deter-
20 FUNDAMENTAL CONSIDERATIONS
mination of their uses, iiioluding the principles (l)ut not the practice)
of their preparation as based upon such facts, and their chissification in
view of medical considerations.
Pharmaceutical Botany. — In its widest scope, Pharmaceutical Botany
would include the classification, phytography, histology, distribution
and culture of medicinal plants, and the collection, preservation,
packing, transport, commerce, identification and selection, composition,
and methods and processes of preparation for use of the drugs derived
from them. From this it would follow that the pursuit of pharmaceu-
tical botany would demand a thorough knowledge of nearly all depart-
ments of scientific botany. This conclusion is to be modified, in view
of existing conditions, in important directions. The pursuit of the
study to such an extent would almost necessarily involve the a^'erage
pharmacist, at least in this country, in financial failure, through the
inattention to practical afl^airs which would ensue. It is the peculiar
office of the teacher of technical science to place its practical benefits
within the reach of his students, while relieving them from attention
to the greater portion of the field. It is not to be overlooked, however,
that while such a process of extensive exclusion is possible, utility
requires that a corresponding degree of elaboration shall be attained
in special directions. The faithful teacher, moreover, will not refrain
from urging as liberal an indulgence in extra-utilitarian study as indi-
vidual circumstances will properly permit. The directions in which
botanical knowledge is most useful to practising pharmacists will
determine the most important requirements for botanical study.
Pharmacognosy. — The identification, valuation, and selection of drugs
— that is to say. Pharmacognosy — constitute the principal field for the
exercise of botanical knowledge on the part of the pharmacist.
It is convenient to divide botanical pharmacognosy, like vegetable
anatomy, into gross and minute, the latter concerning itself with those
characters which require the compound microscope for their demon-
stration.
Subjects Essential to Pharmacognosy. — Remembering that vegetable
drugs may consist of the entire plant or of any one or more parts thereof,
and that they may reach the pharmacist in any condition, from that of
unbroken, or even fresh, to that of a fine powder, the departments of
botany necessarily pertaining to pharmacognosy and materia medica
will appear as follows: A knowledge of classification or systematic
botany, while a prime necessity in medical botany, there being a distinct
co-relation between natural classification and medicinal value, is one
ORDER OF SUBJECTS 21
of tlu> less practical and essential elements of ])liannacentical botany.
Still, it aids the student in the ai)i)licati()n of i)hytography and espe-
cially in understandinfj; distribution, and it serves to crystallize and
systematize his knowledge of groups of medicinal agents. A good
working knowledge of phytography may be regarded as the leading
essential. If the drug is to be sought by the pharmacist in nature, he
can recognize it only through phytography, whether that knowledge be
acquired through folk-lore or book-lore. If, on the other hand, he seeks
the crude drug in commerce, he merely restricts his phytography to the
plant-part under inspection, and so far from being by this consideration
relieved from phytographical labor, its requirements are the more exact-
ing and its methods the more refined, as the recognition and estimation
of a fragmentary representative becomes more difficult than that of the
complete individual. As "Phytography" in its ordinary employment
is about equivalent to "the study of the manifest organs of plants,"
or of their gross units of structure, morphology becomes the key to the
situation.
When drugs come to hand in a comminuted condition, the compound
microscope is the only resource, and the department of plant-histology
becomes the foundation of work. As will be shown farther on, the
greater portion of this subject can be passed over, but that portion
which receives attention, permitting the recognition of detached tissue-
elements and the determination by their examination of their source,
requires observations quite as careful and knowledge quite as accurate
as are called for in any other portion of the field. In the New York
College of Pharmacy, for the students of which this work is specially
prepared, the use of the compound microscope, and the subject of
histology, are separately taught, and the treatment of this important
subject is left to the appropriate department.
Finally, we note that only an insignificant portion of the materia
medica includes the bodies of flowerless plants, so that the great division
of Cryptogamic botany, as regards its detailed treatment, is not essential
to Pharmacognosy.
Order of Subjects. — In attempting a comparative view of the series
of plants, it is unquestionably well to begin with the lowest form and
follow the line, or rather lines, of ui)ward (kn-elo])ment; but in gaining
our first knowledge of the structure of the })lant organism, sound and
accepted rules of pedagogy require that we begin with the more obvious
characters of the higher plants, and pursue the analytic method, so far
as the special conditions of the case will ])erniit.
22 FUNDAMENTAL CONSIDERATIONS
It has been repeatedly remarked that ])hint hfe is a circle of germina-
tion, growth, and reproduction, passing again into germination. It
therefore makes little difi'erence, on general principles, at which point
we enter upon our series of observations. Begin where we wull, we must
labor at the disadvantage of requiring more or less knowledge of facts
preceding our point of departure, and therefore not as yet possessed.
In special cases, however, there is much more room for choice, and
there are many reasons why we would advise pharmaceutical students
to commence b}- observing the organ concerned in reproduction, namely,
the flower.
CHAPTER II
ANTHOLOGY: THE GENERAL NATURE OF THE FLOWER
The Phytomer. — In order to accurately understand the structure of
the flower, we must first consider the general characters of its struc-
tural units, which are the same as those of the stem upon which it
is borne and of which it is a part. These are well displayed in a
willow twig (Fig. 1), presenting a main stem, with perhaps short
branches below and leaves above. These leaves are found, upon exami-
nation, to arise at regularly occurring points, thus dividing the stem
into parts which are seen to possess definite and uniform characteristics.
In common language these parts are called "joints," and technically,
Phj'tomers or Phytons.
Units of Structure. — The upper portion of each phyton is commonly
somewhat enlarged and it possesses the power of giving rise to three new
structures: (1) the leaf (a), or in many plants a circle of two or more
leaves; (2) a superimposed phytomer, continuing the growth of the
stem in its original direction; (.3) a branch extending the growth of
the stem in a lateral direction, or, if there be more than one leaf, then
a corresponding number of such branches. Upon the upper portion of
the stem the branches are seen still undeveloped, and in the form of
buds (6). The bud originates, with rare exceptions, at the point where
the leaf emerges from the stem and upon its upper side. This point is
known as the Leaf-axil. The portion of the phytomer which gives
origin to these three structures is called its Node (c). The portion
intervening between two nodes is called the Internode (d). The inter-
node does not normally possess the power of giving origin to these
new parts.
The branch is found, after development, not to differ essentially
from the stem, so that a branch may be regarded as a lateral stem,
secondary, tertiary, and so on. In noting'hereafter the development of
the other parts of the plant out of those here named, we shall frequently
find the latter so modified that we shall be unable to recognize them
by the ordinary methods of examination, so that the relative positions
which they occupy will prove an important guide. A correct under-
24 ANTHOLOGY: THE GENERAL NATURE OF THE FLOWER
standing of morpholo^n- requires, tiierefore, that we keep in mind the
following faets relating to the internode, no(k', U-af, branch, and super-
imposed phytomer.
1. Any of them may remain more or less undeveloped.
2. There is a definite and regular arrangement as to position of the
leaves upon the stem in most cases.
3. Several leaves and as many branches may develop from one node.
4. The branch normally develops as a bud in the leaf-axil, and con-
versely a leaf, in some form, is normally at the base of each branch in
its rudimentary condition.
Fig. 1. Leafy twig of
willow, its phytomers separated, a, leaf; b, axillary bud; c, node; d, internode.
5. All growth developing in the leaf-axil, with the exception of hairs
and similar appendages, is a manifestation of the branch.
6. All organs of the plant which w^e consider, except the root, the
hairs, etc., are constructed of the above parts in some modified form.
Certain necessary qualifications of the above statements can be made
only when we come to the study of the stem, and these do not involve
any failure to understand correctly the principles of anthology.
Propagation by Nodes. — Before proceeding to consider the forms of
structural modification of phytomers in the development from them of
fMOnRTY LIBRABff
J». C State C#««««
PROPAGATION BY NODES
25
the fl()\v(>r, certain iini)()rtiiiit i)r<)i)erties ])ertaiiiiii<i; to tlieiii, in addition
to their abihty to inultii)ly and grow as above indicated, shouhl receive
attention, in onh'r tliat hiter a comparison of reproductive methods can
l)e instituted. It is found that if, in the case of many plants, a stem
be laid prostrate in the soil, its connection with tlie parent not destroyed
(P'ig. 2), its nodes, in addition to jwoducing branches (a), may develop
roots (/;) similar in structure and function to those of the parent. If
now the phytomers be sei)arated through some portion of the internode,
they will heal the wound so produced by the formation of a callus (c),
continue to grow independently, and become plants similar to the parent.
Such a process, here of artificial production, is of frequent natural
occurrence and is called Propagation. It is seen to be, in this case,
purely vegetative, and may be defined as the production by vegetative
processes of a plant-body growing independently and separately from
that from which it was derived.
Fig. 2. Propagation by layering, a, axillary bud developed into a stem; b, adventitious roots;
c, callus.
Various other modes of stem-propagation may here be referred to,
and it may be remarked that the process is not confined to the node,
occurring in exceptional cases from fragments of the internode, root,
or even leaves. The phytomers, instead of remaining attached during
the rooting process (Layering), maybe first separated (Propagating by
Cuttings). The cutting, in this case called a Scion, may be inserted
(Grafting) or a bud may be so inserted (Budding) imder the bark of a
living stem, or it may be caused to take root in the soil. Propagation
by tul)ers or parts of them, as in the case of the potato, is identical.
It may be remarked, in passing, that in tlic seed itself nature resorts to
a similar method, for the contained embr\() consists of one or more
26 ANTHOLOGY: THE GENERAL NATURE OF THE FLOWER
phytomers. This process is, however, sexual, and is called Repro-
duction.
Composition of the Stem. — Roughly stated, the stem may be said to
consist of three portions: (1) A framework consisting of strands of
conducting vessels (54, g), associated commonly with fibers; (2) among
and around the last a quantity of soft non-fibrous tissue; (3) a covering,
membranaceous when young and changing greatly with age.
Composition of the Leaf. — All these parts are extended into the leaf,
the first existing in a system of branching ribs or veins, the second as a
filling in the meshes of the former, and the third as a highly developed
skin-like covering, the epidermis.
Parts of the Leaf. — Morphologically considered, the typical leaf
(Fig. 3) consists of three parts which, like those of the stem, will be
considered in detail hereafter. The base (a) bears the Pulvinus or
organ of attachment to the stem, frequently
extended into an encircling sheath, and upon
either side a membranous expansion (h) called
the Stipule. The stem of the leaf (c) is called
the Petiole. The blade {d) is called the Lamina.
In some plants an additional organ, the Ligule,
develops as an appendage upon the face, being
a modification of the stipule (Fig. 465, A,h).
Modification of the Structural Units. — If we
could observe the phytomers of such a twig
during the process of formation in the bud
(Fig. 4) we should find them in a more and more
rudimentary condition towards its apex or center
until we reached an ultimate growing point («),
where development had not yet manifested itself.
Yet this point would possess the power, under
proper conditions, of continuing the process of
development and growth of phytomers. It therefore may be said
to represent a certain amount of vital energy or potential growth.
Now, our fundamental ideas of flower structure rest upon the fact that
this vital energy or potential growth may be diverted from the produc-
tion of phytomers and leaves such as we have been considering and
may produce in their stead other structures in which resemblance to
and variation from them are mingled in variable proportions. These
new structures we then call Modified Phytomers and Modified Leaves.
The student should dwell upon this point until the exact meaning of
Fig. 3. Leaf of willow, a,
pulvinus or foot; 6, stipules;
c, petiole; d, lamina. 4. Dia-
gram of longitudinal section
through bud. a, the growing
point.
THE FLOWER CLUSTER IS A MODIFIED BRANCH
27
these terms becomes clear. When hereafter he encounters, as he very
frequently will, a reference to some organ being modified or transformed,
it must never be understood that it was first produced and then changed.
The exact meaning is that the change takes place in the direction or
exercise of the energy which is to ])roduce the modified structure.
Modification Produced by Injury. — Such a diversion of energy may be
caused by accident, as seen in the so-called "Willow-cone" (Fig. 5),
resulting from an injury inflicted by an insect in depositing its eggs in
P
8
10
Fig. 5. Willow twig with tip transformed into a gall-cone through insect agency. C. Willow twig
after fall of leaves. 7. The same with axillary buds enlarged, in spring. S. The same with axillary
buds developed into (a) female flower-bearing branches, c, scale (modified leaf) from one of the nodes
of "a." 9. Scale with its axillary bud developed into a flower, consisting of a pistil only, o, the stipe;
6, the ovary; c, the style; d, the stigmas. 10. Longutidinal section through willow pistil, a, placenta;
h, ovule.
the center of a bud. A portion of the structures, ha\ing been originated
before such injury, will reach a partial development, but further pro-
duction is checked and a distorted product results.
Bud-scales are Modified Leaves. — In the cases which we shall have
to consider the modification dates from an earlier stage and is natural
and physiological, instead of pathological, as in the case of the willow-
cone. Fig. 6 represents a twig after the fall of its leaves in the autumn.
Each bud is seen protected by its lowest leaf, permanently enlarged,
and developed into a covering scale. At the base is seen the scar of the
leaf in the axil of which the bud was developed. Fig. 7 illustrates the
twig in the spring after early growth has enlarged the buds.
The Flower Cluster is a Modified Branch. — In Fig. 8 (a) the covering
scale has fallen, the branch has developed to a length of an inch or so,
28 ANTHOLOGY: THE GENERAL NATURE OF THE FLOWER
and its structure can be seen to consist of a great number of very short
phytomers, each of the crowded nodes bearincf a scale (c) and in its
axis (Fig. 9) a peculiarly shaped body (a, b, c, d). These bodies, as we
shall soon see, are flowers, and this entire bunch is a flower cluster.
That the scales are modified leaves is proved not only by their position,
as pre^•iousl^' explained, and to be further explained in our study of the
leaf, but by the fact that in exceptional cases the branch will produce
them in a form intermediate between that of a scale and of an ordinary
leaf (Fig. 13, a).
Each Flower of the Cluster is a Modified Branch. — Such being the case,
anything produced in their axils must, according to the same laws of
position, be modified branches. We must therefore regard the flower
shown in Fig. 9 in the axil of the leaf, as a modified branch, one of a
great many produced upon the parent modified branch shown in Fig. 8.
How profound is the modification which has taken place in the latter
can be appreciated from a consideration of its reduced size, for it is now
approximate!}^ full grown. The great number of phytomers upon it,
had they reached the form and extent of development reached by those
in Fig. 1, would have produced a branch many feet, or even yards, in
length, whereas in their present form they will produce a structure only
an inch or two long. As we shall soon see, increased complexity
of structure has replaced the greater amount of tissue-growth of
the leafy branch, a cluster of flowers having been produced in its
stead.
The Flower Explained and Defined. — Examining now the little modified
branch (Fig. 9) taken from the larger branch (Fig. 8, a), we observe
that it presents two uniform portions or halves, united into a single
body except at the tip, where they are separate. In exceptional cases
we find this separation extended downward, perhaps even to the base
of the body, and each of the separated portions expanded, formed and
veined very much like a small leaf, which, in fact, it is. The little branch,
a, b, c, d, is thus to be regarded as bearing two leaves which have been
developed in a united condition. Upon dissection (Fig. 10) the body
thus formed from these two leaves is found to be hollow at one portion,
containing two slight projections upon its inner wall (a), and upon these
a number of minute rounded bodies (6), If allowed to develop and
mature under the requisite conditions, we should find that these bodies
had become seeds. The structure ])roducing them we now see to be a
branch, so modified as to produce seeds, and this constitutes our definition
of the flower.
THE PISTILLATE OR FEMALE FLOWER
29
Some Flowers are Imperfect. — It does not follow that because con-
structed for the production of seeds, a flower is always capable of per-
forming this office independently, and, indeed, such is not the case with
the flower under consideration, which is, therefore, an Imperfect ore.
Sex and Sexual Reproduction.- — INIinute microscopical examination
discloses within the bodies which are to become seeds, minute structures
called JNlacrospores, which, after germination and growth in that i)lace,
produce cells comparable, in their essential characters, to the ova of
animals, and requiring a similar fertilizing process to cause their develop-
ment.* Flowers, or at least certain of their products, are thus seen to
possess sex and to be capable of performing sexual reproduction, or
reproduction proper. Commonly, both sexual parts are present in one
flower, and of these the female, the 2-leaved branch here considered,
and in this case all that there is to the flower, is called the Gynaecium,
frequently represented by the symbol G.
Fig. 11. Willow twig with axillary buds developed into (a) male flower-bearing branches. 12. Scale
(modified leaf) from 11, a, with its axillary branch developed into a male flower consisting of two
stamens, a, position of node; b, scale; c, filament; it. anther. 13. .Abnormal willow twig, the scales
(o) of its flower-bearing branch intermediate between the ordinary form and the leaf.
The Gynaecium is Composed of One or More Pistils. — In Fig. 47, the
gynaecium consists of fl\c such bodies, and in other flowers it consists
of various numbers. One of them is called a Pistil, so the gyn;;ecium
may consist of but one, or of any number of pistils.
The Pistillate or Female Flower. — This flower (Ing. 9) possesses only
the gynaecium, and is therefore often s])()ken ( f as a "Female Flower,"
technically a Pistillate flower, and indicated by the .-symbol •..
* For an explanation of this subject see Chapter IX.
30 ANTHOLOGY: THE GENERAL NATURE OF THE FLOWER
Fig. 14. Diagram representing
transverse section through anther,
o, theca, containing pollen; 6, con-
nective; c, locellus. 15, alder twig.
o, pistillate-flowered branches; b,
staminate-flowered branches.
The Staminate or Male Flower. — Before considering the structure of
the pistil we will examine a "JNIale Flower," borne, in the case of the
willow, upon a plant which produces no pistillate flowers. Fig. 11
illustrates branches (a) crowded with male
flowers each (Fig. 12, a), as before, in
the axil of a scal^ (6). In this case the
two modified leaves forming the flower are
entirely separate and the hollow portion of
each {d) is small, borne at the summit
of a stem (c) and filled (Fig. 14) with a
great number of minute rounded bodies.
These correspond, though of the other sex,
to the macrospores which we have found
the pistillate flower to produce, and they
are called IMicrospores — in flowering plants,
Pollen-grains, They possess the power of
germinating, growing, and producing Male
Cells, comparable to the spermatozoa of
animals, and requisite for the fertilization of the corresponding egg-
element produced by the macrospores.
The Androecium is Composed of one or more Stamens. — The male por-
tion of a flower is called the Androecium, frequently indicated by the
symbol A, and it consists of one or more Stamens, in this case of two.
As this flower consists only of androecium, it is known as a Staminate
Flower, indicated by the symbol d.
The Sporophyte, Sporophyll, and Sporangium. — We have now seen that
both the stamen and the pistil, homologues of leaves, exist for the
production of spores. A modified leaf producing spores is called a
Sporophyll. Both the stamen and the pistil form hollow bodies for
containing one or more spores. Such a spore-case is called a Sporangium
or Sporange. A plant producing sporophylls and sporanges is called a
Sporophyte. JMacrosporophytes, Macrosporophylls and Macrospor-
anges are those producing only macrospores or female spores. Micro-
sporophytes, Microsporophylls, and INIicrosporanges are those producing
only microspores or male spores.
Dioecious, Monoecious and Polygamous Flowers. — When, as in this
case, the macrospores are produced })y one plant and the microspores
by another, the plant is dioecious. If in addition each plant produced
some perfect flowers it would be Dioeciously Polygamous. If, as in the
Alder (Fig. 15) pistillate flowers (a) and staminate flowers (b), or other-
PARTS OF THE PISTIL 31
wise stated, spores of both sexes, are produced by tlie same plant, it
is Monoecious. If, in adition, the phmt bear some perfect flowers it is
Monoeciously Polviianious.
Hermaphrodite and Perfect Flowers, — When, as illustrated in Fig. 17,
the flower possesses both gynaecium and androecium, it is Hermaphro-
dite, indicated by the symbol 9. Hermaphrodite flowers are not
always perfect, as one of the organs, while perfect in form, may be
functionless; whereas, in order to be perfect, both parts mnst be present
and functionally active.
Degrees of Imperfection. — Imperfect flowers present all intermediate
grades between that last mentioned and that in which there remains
no trace of the lost part, or in which it has even been transformed into
an organ of a different kind.
Parts of the Stamen. — The stem-like portion (Fig. 12, c) regarded as
corresponding to the petiole of the sporophyll, is the Filament. The por-
tion containing the spores or pollen is the Anther (d). The two halves of
the anther, each corresponding to a half of the lamina of the sporophyll,
are the Thecae (Fig. 14, a). At an earlier stage each theca is subdivided
into two Locelli (Fig. 14, c), and in many plants this condition persists
to maturity (Fig. 138). The portion connecting the thecae with one
another and with the filament is the Connective (b). Our detailed
study of the stamen, as of the pistil, may here be anticipated by the
statement that any or all of their parts may in different flowers be found
modified in an extreme degree by reduction, exaggeration, or special
form of growth, and may bear appendages in great variety, their true
nature, or even their identity, in many cases being thus masked. Often
an a])i)endage aj)parently consisting of a modified stipule exists.
Parts of the Pistil. — The stem-like base (Fig. 9, a), not present on
most pistils, is the Stipe or Thecaphore. It represents the united
petioles of the sporophylls. The body of the pistil represents either a
single sporophyll having its edges brought together and united, with
the upper leaf-surfaces inside of the cavity (Figs. 219 and 220), or, as
in this case, more than one sporophyll, the edges of one meeting those
of the other in the same manner (Fig. 27, e) or in many cases in a^ifl'er-
ent manner. The edges, after meeting along the hollow portion, project
inward more or less, while along the tip, for a greater or less distance,
they may be everted, as seen in Fig. 17, b. A s])oroi)hyll of a pistil is a
Carpel, and we see that a pistil may consist of one or more carpels.
The seed-rudiments which ])r()duce and contain the macrospores
are the 0^•ules (Fig. 10, b). The outgrowth from the inner wall of the
32 ANTHOLOGY: THE GENERAL NATURE OF THE FLOWER
ovary iipon which the ovules develop is the Placenta (Fig. 10, a). The
hollow portion of the pistil, containing the placentae and ovules is the
Ovary (Fig. 9, b). The divisions of the ovarian cavity, which sometimes
exist, are called Cells (Fig. 221, etc.), and the partitions which separate
them are called Septa or Cell walls. A point upon a pistil (Fig. 9, d)
which lacks its epidermis and permits entrance into the ovary of the
pollen-product is a Stigma. (See also Figs. 191, etc.) A portion con-
necting the stigma to the ovary, narrower than the latter and usually
not hollow, is the Style (Fig. 9, c).
The leafy nature of the Carpel and its products is well illustrated
by Fig. 19, which represents a reverted state of the pistil.
The Essential Organs. — Since the androecium and gynaecium are
capable of producing seeds without the necessity for other floral parts
they are commonly known as the Essential organs, others as the Non-
essential organs.
Protection Needed by the Essential Organs. — The danger of accident,
as the result of blows, punctures, erosion, or even changes of tempera-
ture, to the complex mechanism and delicate structure of the essential
organs, and the resulting necessity for their protection, is obvious. In
the case under consideration the flowers are so closely crowded upon
their supporting branch that their leaf-scales (which are not parts of
the flowers, but grow out underneath them, from the nodes) afford
the necessary protection. But commonly this is not the case, and each
flower must provide and possess its own protecting organs. It must be
borne in mind, however, that protection is usually the least important
office which such organs fulfil.
The Calyx. — A series, or apparent or real circle, of such modified
leaves, underneath or surrounding the androecium, is displayed in the
flower of Pulsatilla (Fig. 16, a) and constitutes its Calyx, frequently
indicated by the symbol K, the several leaves being called either Sepals
or Calyx-Lobes, in accordance with conditions to be considered hereafter.
The Corolla. — Commonly, there is a second series or circle betAveen the
calyx and androecium, as in the buttercup (Fig. 17, a), and this is called
the Corolla, frequently indicated by the symbol C, its several leaves.
Petals or Corolla-lobes, according to their condition. Rare cases
occur in which, although but a single circle is present, it is regarded as
a corolla.
Sinuses. — The space between two adjacent petals or corolla-lobes — and
the same is true of a similar space between any two organs or divisions
standing side by side — is called the Sinus.
THE TORUS
33
Petals and Sepals. — Occasionally the petals will he mimeroiis, forming
more than one circle. A petal or sepal is normally not composed of
distinct parts, unless it be by a narrowed insertion, called the Unguis
or Claw, which is frequently present (Fig. 18, a), the broad part being
called the Lamina, Blade, or Limb. It is then said to be r'nguicu-
late. Usually the form of sepals and petals is more obviously leaf-like
than that of the stames and carpels, and frequently in color and texture,
particularly of the sepals, they are strongly foliaceous. The calyx and
corolla may, however, possess any color or texture and they may be
similar or dissimilar, usually the latter, in this feature. The petals, as
w'vW as the sepals, may even difl'er among themselves in color and texture.
Fig. 16. Flower of PulsaliHa, subtended by epicalyx, with calyx of 6 sepals; a, torus; 6 and c, rudi-
mentary or aborted petals 17. Flower of Adonis, a, petal; &, pistil; c, stamen. 18. Unguiculate
petal of Diaiithus. a, unguis or claw. 19. Flower with its carpel partly reverted to the leaf-form.
The Perigone. — The calyx, or the calyx and corolla together when both
exist, constitute the Perigone, less aptly called the Perianth or Floyal
I'nvelopes. A flower possessing both calyx and corolla is called
Dichlamydeous; one with calyx only, Monochlamydeous, indicated
by Co, and one with neither, Achlamydeous or Naked, indicated by
Ko-Co. Those which have no corolla are called xA.petalous.
The Complete Flower. — A flower possessing calyx, corolla, androecium,
and gynacciiini is called Complete.
The Neutral Flower.— Some i)lants habitually i)roduce a portion of
their flowers without essential organs (Fig. 2(18, a). Such flowers are
called Neutral.
The Torus. — It must ever be borne in mind that all these parts are
constructed of the modified leaves of the floral branch. The latter is
called the Torus or Thalamus, or, less desirably, the Ileceptacle. The
torus may, therefore, be defined as the reduced branch which gives origin
to the jxirts of the /lower {a, in Figs. 10, 23, and 24).
3
34 ANTHOLOGY: THE GENERAL NATURE OF THE FLOWER
Relation of the Flower and its Parts to the Branch and its Leaves. — The
relation of these parts to their branch may be displayed by comparing
the leafy stem of a lily Mith the dissection of a lily flower (Fig. 20).
Fig. 20. Diagram showing homology between leafy stem and flower of lily, the lowest whorl of former
corresponding to the calyx of latter, the second to the corolla, the third and fourth to the two sets
of stamens, the uppermost to the carpels, the torus to the branch.
The Epicalyx. — ^What appears to be a double calyx, or one calyx
outside of another, is frequently seen. This appearance is sometimes
Fig. 21. lAndoiCallirrhoe. a, epicalyx; 6, calyx; c, corolla. 22. The same expanded. 23. Apetalous
flower of Hepatica. a, torus; 6, calyx. 24. The same, calyx removed, o, the torus showing the epi-
calyx as distant.
due to the actual manifestation of two circles, as in the mustard; at
others to appendaging (see Fig. 36), but usually to a circle of modified
THE EPICALYX 35
foliage leaves standing close to the torus (Figs. 21 and 22, a), and
known as the Epicalyx. When, as in this case, the flower has in addition
a calyx and corolla the real nature of the epicalyx is readily understood.
But when (Fig. 23) there is no corolla, the calyx (h) being colored like
one, the epicalyx may easily be mistaken for a calyx. In this instance,
however, it may be seen by turning back the epicalyx or removing the
calyx (Pig. 24) that the point of insertion of the former is upon the
stem below the torus («), so that it can be no i)art of the flower
proper. The divisions of the epicalyx are called Bracts, though the
term is not restricted to this use, as will be seen farther on.
CHATTER III
LAWS OF FLORAL STRUCTURE
Meaning of the Term. — When we speak of a natural law as governing
a certain natural object, we refer merely to some observed mode or
manner of the existence of that object. Thus it is a law that water
flows downward, because that has been observed to be one of the
peculiarities of this substance. Similarly, warm air rises, wood burns
when fire is applied to it, and the sepals and petals of a flower possess
a similar form to that of the leaves of the plant on which they grow
and of which leaves they are homologues. Nevertheless, water will
sometimes run up hill because it is forced up, warm air sometimes does
not rise because it is confined, wood will not burn because it is wet or
otherwise fireproof, and the sepals and petals will not conform with the
leaves because some plants have no leaves, or because the influence of
some other law, known or unknown to us, has interfered with the action
of the one stated.
Under the natural and unobstructed influence of the morphological
development of the flower from a branch and of its parts from the leaves
of that branch, the flower and its parts would possess certain definite
and typical characters. In the process of such development, however,
there is a constant tendency toward variation from the typical state,
the extent and direction of which variation are determined by the
external conditions and forces to which the living plant is subject, so
that, as a rule, flowers differ greatly from that typical state. A careful
study of all flowers will nevertheless show that their general plan of
structure is in accordance with these laws, with more or less variation
in the details.
Modification of the Typical Flower. — We shall here consider the laws
of floral structm-e in relation to the following characters: The relative
number and position of parts of different kinds or of different series, as
those of the calyx compared with those of the corolla, or of the andro-
ecium compared with those of the gynaecium; the separation of each
part from every other, both of the same and of different kinds or series;
a similarity in form and size of the parts composing any one series;
SYMMETRICAL FLOWERS
37
the characteristic form and function of all the parts of one kind. P'or
the identification of the parts of a typical flower, the few illustratiojis and
definitions already given will prove ample, but such flowers are very
rare. The great majority of them de\'iate from the tj'pe in one or more
directions to such a degree and in such a variety as to very frequently
create difficulty in identifying or circumscribing the several parts. To
fit the student for properly meeting the difficulties which so arise, as
well as for understanding botanical terminology, it is necessary to
specify and explain the principal forms of variation and to establish such
a classification of them as their varied nature will permit.
Law 1: Symmetrical Flowers. — The number of parts of each kind or
series is the same as of each other, or they have a common multiple. The
term Isomerous is used to indicate that the same number of parts enter
into the formation of the two or more circles to which the term is appHed.
In the case of the gynaecium, it is the carpels which are counted as
parts of the circle or series, whether developed each as a se])arate pistil,
or all united into one. The number of stamens is normally equal to
that of the sepals and petals com})inctl, that is, they form two circles.
If the flower is typical, the number of stamens will thus be just twice as
great as that of the parts of any other kind. A flower constructed in
accordance with this law is called Svmmetrical.
Fig. 25. Ai>i)ar('iitl.v nioiioniorou.s flowor of I/ippuris. a, raly.\; c, stamen; <i, pistil. 20. Longitu-
dinal section of same. 27. Dinierou.s flower of liicuntUa. a, sepals; b, original petals; 6', petal-like
bodies developed from one pair of stamens; c, the other pair of stamens, each divided into three; d,
pistil; e, eros.s-seetion of ovary, showing two placentae. 28. Trimcrous flower of VercUrutn. 29.
Tetramerous flower of Ocnulhcra. 30. Pentamerous flower of Grrauium.
Terms Indicafin;/ Niuncrical Synivicfri/.— Thus, the flower oi Ilipjniris
(Figs. 25 and 2G) has an entire calyx, apparently of one sepal, no corolla,
38 LAWS OF FLORAL STRUCTURE
one stamen, and one carpel, and is, in its present state, Monomerous
or One-merous. The symmetrica] flower of Bicuculla (Fig. 27) possesses
two sepals (a), four petals (6 and b'), six stamens (c), and a two-carpelled
pistil {d and e), and is Dimerous or Two-merous. That of the Veratrnm
(Fig. 28) is similarly based on the plan of three, and is Trimerous or
Three-merous. Oenothera (Fig. 29) is Tetramerous or Four-merous,
and Geranium (Fig. 30) is Pentamerous or Five-merous. Fig. 43 displays
the plan of such a flower in cross-section and admirably illustrates our
second law also.
Suppression and Duplicatio7i. — Suppression results in the posses-
sion of less parts of one kind than are possessed by the typical flower,
while Duplication results in the possession of more. From what follows
it will be seen that neither suppression nor duplication necessarily inter-
feres with the numerical plan, although they frequently do so.
In the monochlamydeous flower of Pulsatilla (Fig. 16) suppression
of the entire circle of petals has occurred, although vestiges of them
remain. In the staminate and pistillate flowers of the willow, all
organs except a single series are suppressed. In the Claytonia (Fig. 45)
one complete stamen-circle has been suppressed.
In all these cases the remaining parts accord with the numerical plan
and the flowers are still symmetrical. Suppression which thus results
is called Regular Suppression.
Irregular Suppression. — This is displayed in the calyx of Claytonia,
with three of its five sepals wanting, in the androecium of the 4- or
5-merous flower of Horse-chestnut, which usually wants 1 to 3 of the
requisite number of stamens, and in the gynaecium of the 4-merous
flower of the olive (Figs. 31 and 32), which has but two carpels remaining.
In this flower, both forms of suppression appear to have occurred, for
but 2 of its 8 original stamens remain. To irregular suppression the
term Abortion has been applied, while by others this is restricted to
suppression in which a vestige of the lost organ remains, as in case of the
petals of Pidsatilla, and one set of stamens in Fig. 38, a.
Regular Duplication. — Duplication, like suppression, presents a
regular and an irregular form. Kegular duplication is seen in the
5-merous flower of the strawberry (Fig. 36), with its 10 sepals; the
3-merous flowers of Magnolia (Fig. 35), with 6 to 9 petals, and Meni-
spermum, with 12 to 24 stamens, and in the 5-merous flower of Maha,
which frequently has 10 carpels.
Chorisis and Syngenesis. — The development into two or more sepa-
rate parts of an organ originally entire is called Chorisis. This is exhibited
SYMMETRICAL FLOWERS
3d
^-AX
W
/ / /
in the androecium of the mustard, where the multipHcation of two of
the stamens, each into two, has occurred. The development in a united
condition of two or more organs originally
separate is called Syngenesis. This is exhibited
in the two carpels of the mustard, which are
united to form a single pistil.
The nature of the process is illustrated by
the accompanying diagram (Fig. 30 A). Let
a represent a mass of elementary tissue which
is normally to develop into a stamen. If it
develop by a uniform growth throughout the
mass, it will become a single stamen, d. If,
upon the other hand, it grow separately at the points h, c, and d, it
must result in the production of three separate bodies, each of which
^^
Fig. 30 A. Diagram illustrating
the process of chorisis.
Figs. 31 and 32. Tetramerous flower of olive, 6 of its stamens and 2 of its carpels suppressed. 31.
Same in longitudinal section. 33. Androecium of mustard, showing a stamen developed as two,
through chorisis. 34. Flower of Tilia, showing each stamen developed into a cluster and a petal
through chorisis. 37 shows such a cluster detached. 35. Diagram of transverse section of Magnolia,
showing duplication through metamorphosis. 3G. Flower of strawberry, the calyx-appendages simu-
lating an cpicalyx. 38. Androecium of Fsorospermum, the stamens of one set undergoing chorisis,
those of the other aborted into gland-like bodies. 39. Flower of Stellaria, the corolla apparently
double. 40. A petal of the same, bi6d by chorisis. 41. Flower of rarojacHW, the calyx having under-
gone chorisis.
may become a perfect stamen, as represented by the dotted lines. The
process thus results in branching.
40 LAWS OF FLORAL STRUCTURE
The important point for the student to note is that while we should
thus have three stamens as to form and function, we should have but
one as to the numerical plan of the flower, for all have developed from
the point belonging to one, and from the elementary tissues of one, and
all represent but one leaf-homologue. Sometimes the total number of
stamens (or other parts) will thus be multiplied, each element under-
going the same change, while at others only one or two in the circle will
be thus modified. The latter would result in irregular duplication. In
studying the law of position of parts, we must note the great difference
between duplication occurring in this way and that from the develop-
ment of a new circle independently of any process of chorisis. This
peculiarity of position in chorisis is well illustrated by the flower of
Tilia (Fig. 34), where three groups or fascicles of stamens can be seen,
each produced from one, and in that of Psorospermum (Fig. .38) where
there are five, the separation being here confined to the upper portion.
In this case, remains of a suppressed circle of stamens are present in the
form of gland-like bodies (a). Chorisis is well displayed in the calyx of
a floret of the Dandelion (Fig. 41), whose sepals have become divided
into numerous bristle-like portions, and in the corolla of the SteUaria
(Fig. 39), each of whose petals (Fig. 40) has become divided into two.
Production by Chorisis of a Part of a Different Kind. — Chorisis some-
times produces an organ of a difterent kind from the original, as in the
case of the original stamens of the Tilia, where each, besides dividing
into about 7 stamens, has at the same time yielded one or more little
petals (Fig. 37, a) standing in front of the stamen group.
Median and Lateral Chorisis. — Chorisis is Median in the case of the
last-mentioned petals, which stand in front of the organ out of which
they were formed. Lateral in the case of the stamens, which stand
beside the organ out of which they were formed.
An Indefinite Number of Parts. — When the number of organs of one
kind, as of petals, as in the rose (Fig. 59), or of stamens (Fig. GO),
exceeds twenty, it is commonly spoken of as Indefinite, indicated by
the symbol go , although in most cases it falls within certain definite
upper and lower limits which are of diagnostic value.
Indication of the Numerical Plan by Diagram. — The numerical plan
and deviations therefrom are often indicated pictorially by diagrams
like that shown in Fig. 43. When dots are introduced, as in this dia-
gram, they indicate the position of organs which should be present in
accordance with the floral type, but which have in that case suffered
suppression. A diagram thus marked is called Theoretical, while if
ALTERNATION OF POSITION
41
the (lots arc omitted it is called Empirical. Frequently, also, a dot is
placed above the dia<,n-am to indicate the jiosition of the plant-stem on
which the flower is borne, this being the Su])erior or Posterior side of
the flower, while underneath it is often indicated the leaf or })ract in the
axil of which it is situated, this being the Inferior or Anterior side of the
flower,
^S o
Fig. 43. Diagram of transverse section of Geranium, showing the alternation of parts. 44. Vertical
view of Illipe, one set of stamens alternating with, the other opposite to, the corolla-lobes, and several
of the stamens aborted. 45. Flower of Ctaytonia with outer set of stamens suppressed. 46. One of
the remaining stamens anteposod to petal. 47. Typical flower of Sedum. 48. Slightly irregular
coToWa. of Pelargonium.
Iiultvditon (if ilic Xiinicricdl Plan hi/ For/// ///a.- -The inanner of
indicating by formulae the numl)er of parts in calyx, corolla, androecium,
or gynaecium has already been indicated. It will now be seen that by
a combination of these expressions, the entire plan of the flower can
be indicated by a single formula. K3, C3, A3 + 3, G- indicates 3 sepals,
3 petals, 2 circles of 3 stamens each, and 2 carpels. K3, C3, A^ + 0, G^,
would indicate that the second circle of stamens had suffered suppres-
sion, but each of the first circle had divided into three. In a diagram,
the positions of the suppres.sed stamens would be indicated ^ ^-^
bv dots, while the doubled set remaining would be indicated in /. . o
pairs, thus: The letter n, in j)lacc of a figure, as in the follow-
ing formula, Ko, Go Ao + n, G'', indicates that the number of parts of
that kind (in this case the stamens of the second circle) is not constant.
Law 2 : Alternation of Position. The parts of each circle alternate in
position with those of the adjacent circles. In other words, each i)art of
42
LAWS OF FLORAL STRUCTURE
the flower stands opposite a sinus of the adjacent outer and inner circles.
Thus, in Fig. 44, the stamens of the circle nearest the corolla-lobes
alternate with the latter, while those of the next circle alternate with
the former and are consequently opposite to the corolla-lobes. In Fig.
43 the same relation can be observed between the other circles. It is
thus clear that the parts of two alternating circles, as of the first and
third, or the second and fourth, must stand opposite each other, or in
the same radial line.
Anteposition Resulting from Suppressioji. — It is also clear that if
two circles shall be brought into juxtaposition by the suppression of
an intervening circle, their parts will naturally stand opposed and thus
appear to invalidate our second law, as in the case of the stamens and
"Vi>^.
J7
Figs. 49 to 53. Figures illustrating torsion.
petals of Claytonia (Figs. 45 and 40), where the stamen-circle originally
standing between the other one and the corolla has been suppressed.
Organs thus placed, the one directly in front of the other, are called
anteposed.
Note should also be taken of the fact, already pointed out, that the
cluster of organs produced by chorisis corresponds in position with the
single part by the modification of which it was produced.
Position Sometimes Obscured. — In examining the position of parts
great care should be taken by the student to see the actual point of
insertion, as the free portion of an organ frequently deviates from the
line of its true position and leads to error.
Torsion. — One such condition which can easily lead to error is
Torsion, or twisting. This relates to a permanent condition of the
REGULARITY 43
mature organ and not a temporary eml)ryonic state such as the twisting
of the coroUa in the bud. Torsion of the base of the coroHa is shown in
Fig. 49, of the stamens in Fig. 50, of the anther in Fig. 51, of the style
in Fig. 52, and of the fruit in Fig. 53. Torsion also frequently affects
other parts of the plant, especially the stems of flOwer and leaf.
The treatment of the subject of position here presented is necessarily
superficial and incomplete, owing to our failure to have considered
already the subject of leaf-arrangement. There is a direct correlation
between the arrangement of foliage-leaves and the parts of the flower.
As the arrangement of the former is sometimes by circles or whorls and
sometimes by spirals, it follows that some flowers may be arranged on
the former plan (Fig. 20), some (at least in part) upon the latter, and
such we actually find to be the case. There is no one of the floral series
but what at times exhibits in its parts (in most cases when they are
numerous) a well-marked spiral arrangement. Such are denominated
Acyclic, while those having their parts in true whorls or circles are
called Cyclic.
Flowers Normally Possessing hut One Stamen-circle. — It should be
noted that the very frequent occurrence of flowers possessing but one
stamen-circle, and this alternating with both carpels and petals, has
led to the belief that in some plants but one stamen-circle is the rule, a
second calyx-circle existing instead of the second stamen-circle. Care
should be taken not to confuse the idea of this second calyx-circle with
that of the totally different epicalyx.
Law 3: Regularity. — The parts composing one circle agree in form and
size. A How'cr all of whose circles obey this law is liouular. An illus-
tration is found in the flower of Veratnun (Fig. 28).
Ir regular it y and How it May Result. — Irregularity may result from
abortion (Fig. 44), where three of the upper circle of stamens are
different from the other five; from appendaging (Fig. 05), where one of
the five petals bears a long spur; or from mere variation in form (Fig.
110) or size (Fig. 48). Sometimes, as in the last case, the variation is
so slight that the student will be in doubt as to its existence, while at
other times an accidental variation in an individual plant may suggest
irregularity where it is not a characteristic. Very often an irregularity
so slight as to be scarcely perceptible in the open flower may be more
conspicuous in the bud. In cases of doubt the relationship of the plant
to others whose flowers are regular or irregular may aid to a decision.
A tendency to antero-posterior irregularity in flowers would apjiear
to be generally characteristic of their higher development.
44 LAWS OF FLORAL STRUCTURE
Law 4. — Each part of a circle develops separate and disconnected from
all others in that and in other circles. As the mass of tissue forming
each of the floral parts becomes isolated and projected from the torus,
its margins and faces should develop completely separate from those
of all adjacent parts. The law assumes that growth shall continue in
the isolated portions, by which process they must continue separate.
But this form of growth of the parts does not always occur. Very
commonly the point of growth changes or becomes restricted to the
basal portion, where they have not yet separated from one another.
This projection from the torus of an undivided or unseparated portion,
and its subsequent growth, must clearly result in the development of
a portion of the flower consisting of more than one floral part in union.
The component parts are usually indicated by more or less of a separa-
tion of their apical portions. This principle has been already carefully
explained in connection with Fig. 42.
Connaiion. — There is no other direction in which deviation from the
type represented in Fig. 47 is so frequent and variable as in that just
described, nor in which the results are so far-reaching or call for so
extensive a classification and terminology. The deviations are of two
classes. When a part is united laterally with another part of the same
circle the condition is called Connation, Cohesion, Coalescence, or
Syngenesis. When connation does not exist the parts are said to be
Distinct or Eleutherous. Connation will be discussed in our detailed
consideration of the several floral parts.
Adnation or Adhesion. — In the second form, called Adnation or Ad-
hesion, one circle is more or less united with another. Adhesion may
affect any two or more circles of the flower, and it may affect an entire
circle or only one or more of its parts. Thus, Fig. 54 illustrates a
petal of the ^'anilla adnate to the ganaecium, while the other petals
are free. It is plain that when the calyx and gynaecium are adnate, all
the intervening circles must be included in the condition, as in the
lower portion of the colocynth (Fig. 5(5). Since all the parts start
from the torus at a, they must be adnate to the whole surface of the
ovary between the points a and /;.
Epigyny. — In the last case, as in all cases where one or more circles
are adnate to the gynaecium, the free or ununited ends of the parts
must lose the appearance of emanating from the torus and must appear
to emanate from the gynaecium. They are, therfore, said to be Epigy-
nous. At this ])oint the student should not fail to impress himself
with an understanding of the fact that in all such cases the epigynous
THE IIYPANTIIIUM
45
organs really orifjinate at the torus, and that in a cross-seetion through
the adherent ])()rti()ns the niieroseope will often demonstrate the tissues
of such a part adnate to those of the part from which it appears to
emanate. In descriptive i)hrase()logy, the term "Calyx adherent"
always means "adherent to the ovary," or ejjigynons, e\en though the
Fig. 5-1. Adnate petal of Viuiilhi. Tm. (iynaiiilnius slauieiis i.f .\,l,iihim, as prevalent in the Apo-
cynaceae. 56. Flower of rolorjnth, with inferior ovary and superior (adherent) calyx. 57. Longi-
tudinal section through flower of I'Mox, .showing stamens adherent to corolla. 58. The same through
flower of cherry, showing adhesion of all parts except the pistil. 50. "Double" flower of rose, showing
the stamens of tlio ".single" fiower (60) transformed into ix'lals.
words "to the ovary" are omitted
condition is to say "Ovary inferior
Another mode of stating tl;e same
r " ( 'alyx su])erior." It frc(iuentl\-
happens that the condition is only partial, when the terms "Half
inferior" and "Partly inferior" are emi)loyed. 'riure are cases where
proper aj)])lication of any of these tei-nis is doiihtful and some ])fr))h'xity
is created.
The Ili/ixnilliliini.- In many cases tlie toiMis, wliicli is to he remem-
bered as the end of a hraiich, is hollow and has the lower portion of the
flower inside of it and adherent to the inner surface of its cup (Figs.
46 LAWS OF FLORAL STRUCTURE
59 and 60). In this case the outer surface of its cup may be mistaken
for that of an adherent calyx. The enclosed portion of the calyx really
is adherent, but it is not visible, since it is enclosed and concealed by the
hollow torus, which is known as a Hypanthium. It is often extremely
difficult to distinguish between a simple adherent calyx and a hypan-
thium, and good botanists frequently disagree in particular cases.
Perigyny. — The insertion of a corolla or an androecium which is
adherent to a free calyx, as in the cherry (Fig. 58), or of an androecium
adherent to a free corolla, as in the Phlox (Fig. 57), is denominated
Perigynous.
Hyvogyny. — Organs which are not in any way adherent are denom-
inated Free, and because their insertion is manifestly upon the torus
underneath the gynaecium, they are said to be Hypogynous (Fig. 47).
Gynandry. — With the stamens adnate to the pistil the flower is said
to be Gynandrous (Fig. 54). The body thus formed of the united
androecium and gynaecium is technically known as the Column. (See
also "Stamen^column.") A peculiar form of gynandry is common
among the relatives of the Apocytmm (Fig. 55).
Law 5. — Each part preserves its own function and a characteristic form.
The forms freeing with this law correspond in general with those
which have been indicated in our account of the flower. Deviations
from it are caused by INIetamorphosis, Enation, resulting in the true
appendaging of an organ, the very similar process of exaggeration in
the growth of a part, retardation in its growth, or its suppression or
abortion. With the exception of the first, the results of these processes
will be discussed under the details of the respective parts.
Metamorphosis is the simulation in form or function, or both, of one
organ by another. The rose, which normally has but five petals (Fig.
60), is seen under cultivation to consist of a dense mass of them, in
many circles, becoming a so-called "double" flower. An examination
of the inner petals of such a flower (Fig. 59) discloses that they are
successively smaller and more stamen-like as they stand nearer the
stamens, indicating their origin through the metamorphosis of the
latter, which are fewer in proportion as the petals are more numerous.
In another form of the rose, the " Green Rose," the petals in turn appear
transformed into leaves or leaf-like bodies. Such accidental or artificial
deviations from the normal type are called Monstrosities. The sepals
also frequently present a leafy appearance, sometimes as an abnormality
but in most species habitually. Even the stamens and carpels fre-
quently display the latter abnormality.
GLANDS
47
Retrograde Metam or pilosis. — In all of these cases the change is from
a more com])lex organ, or one of higher rank, to one of a lower, and is
called Retrograde i\retani()r])hosis, or Reversion of Type.
Progressive Metaiitorphosis also occnrs. It is seen in the gradual
transformation of bracts, themselves transformed leaves, into sepals
in the Barberry (Fig. (il), and of sepals into petals and petals into
stamens. Even stamens may become metamorphosed into carpels
or carpels into stamens, one instance being the flowers of the willow,
where organs have been seen intermediate in ai)pearance between the
two.
62.
Fig. 61. Structures from flower of licrhrris, interiiiodiate between petal and stamen. 62. Same
from flower of Castalia.
Teratology. — Cases of abnormal retrograde metamorphosis are very
common, and have given rise to a separate department of study known as
Teratology.
Enation or Outgrowth. — Enation and the effects ])rodnced by it are well
illustrated in one of their forms by the petals of certain genera of the
Ranunculaceae. The retention of a drop of nectar at the base of the
petal of some species of buttercup is effected by the presence there of a
minute scale (Fig. 03), covering over a slight depression. The nectar
is partly lodged in this pit, partly held between the petal and the
scale. In the Coptis (Fig. 04), a closely related plant, the dej)ression
is deepened into a more obvious cavity and the .scale is dispensed with,
while in the Delphinium. (Fig. 65) the cavity becomes a long tube.
Glands. — Although the detailed consideration of appendages will
be taken up in connection with tlie several organs to which they apper-
48
LAWS OF FLORAL STRUCTURE
tain, we shall here consider a special class of them, called Glands, not
only of great importance in diagnosis and classification, but of such
physiological importance that from that jxnnt of \\e\v they constitute
a distinct organ of the flower. For the peculiarities of structure and
secretory function of glandular tissue, works on histology must be
consulted. Here we note that although glands are sometimes distributed
through the other tissues in such a way as to be imperceptible on
superficial examination, their tissue is at other times collected into more
or less conspicuous bodies of definite form and position. The term
"Gland" is frequently applied also to
bodies which resemble glands in location
and form, but which do not appear to be
glandular in function. Glands may be
stalked (Fig. 66, a), sessile (Fig. 67, a),
or depressed (Fig. 6S, a, see Nectary),
and they may develop upon various parts
Fig. 63. (a) frontal; (b) lateral, views
of base of petal of buttercup, showing a
scale which retain nectar in nectary.
64. Petal of Coptis, hollowed to form a
nectary. 65. Long hollow spur forming
nectary in flower of Delphinium.
Fig. 66. Stalked glands (a) on calyx of Dinemandra.
67. Sessile glands (o). 68. (a) Depressed glands (nectary)
on petal of Frasera. 69. (a) Basal gland prevalent in
the Apocynaceae. 70. (a) Glands at base of stamen of
Sassafras.
of the flower or plant. Those upon the outside of the calyx are exten-
sively utilized in classification in the family Mali)ighiaceae, Avhile those
upon the inside are so used in the families Apocynaceae (Fig. 09, o) and
Gesneriaceae.
Fig. 6S is an illustration of glands located upon the corolla, while
Fig. 70, a, illustrates them connected with the stamens, as seen in
Sassafras.
Glands upon filament-like stalks, suitably located, may easily be
mistaken for stamens, (ilands may be themselves appendaged.
As to their origin, it may be stated that glands frequently result
EXAGGERATION OF GROWTH 49
from metamorpliosis of the remains of an aborted orj?an. Thus, in the
staminate willow-flower (Fig. 12) a small gland between the bases of
the stamens is supposed to represent the aborted pistil, while similar
ones at the base of the pistil, in the pistillate flower (Fig. 9), are supposed
to represent the aborted stamens.
The misleading effects of su])pression have been observed in Ilcpatica
(Figs. 23 and 24) in the absence of the corolla, the metamorphosis of
the calyx toward corolla and of the epicalyx toward calyx. Those of
abortion are seen in the Pulsatilla (Fig. 16), where the petals b and c
are reduced to simulate filaments.
Exaggeration of Growth is well displayed in the torus of the straw-
berry and the placentae of the watermelon (Fig. 312), which respec-
tively contribute the massive edible portions of those fruits.
The principles of anthology as api)Iied to the higher types of plants,
having thus been followed into and through the typical flower, and the
general nature of the deviations therefrom having been outlined, we
shall proceed to a detailed consideration of the several parts of the
flower, with the object of preparing us to interj)ret the multiform
appearances which those organs present in the extensive flora from
which our drugs are deri^'ed.
That division will not, however, close our consideration of flower
structure, as some imi)ortant modifications will remain to be discussed
in our chai)ter on pollination and fertilization.
CHAPTER IV
THE PERIGONE
Study of the Perigone.— The perigone is to be studied as to the number
of its circles, their color, texture, and surface, the number of parts
forming each, their adhesion or cohesion, if existing, the form and
divisions, if any, of each and of its parts, appendages, secretions, meta-
morphosis or other variations, arrangement of the parts in the bud,
movements or other noteworthy habits, and duration.
Number of Parts. — The normal condition of two circles, the modifica-
tion of these through abortion, suppression, duplication and meta-
morphosis, and their agreement with the numerical plan of the flower
and its modification through the same influences, need no further
discussion. The number of parts entering into either perigone circle,
whether these exist in a distinct or coherent state, is indicated by the
appropriate numeral preceding the suffix "phyllous;" thus Monophyl-
lous, Diphyllous, Triphyllous, and so on.
Color and Texture. — The typical idea of a calyx more or less herba-
ceous and a corolla thin, delicate, and brightly colored, is not always
realized. In the Crocus and most related flowers the parts of both
circles are similarly petaloid. The petals of Garcinia are thick and
fleshy, in Caopia they are leathery, and in Alzatea hard and almost
woody, at least when dry. The surfaces of the sepals, particularly the
outer, are not commonly glabrous, while those of the petals are; but
even the latter are often glandular, pubescent, densely woolly, or even
prickly. No shade of color is denied to either circle of the perigone,
nor is the color necessarily uniform among its parts or even over the
surface of any one part. The shade and marldngs are very liable to
vary in different individuals of the same species, so that color is not
always a good character on which to base a determination. In general,
the color deepens as the altitude of the habitat increases.
Form of Parts. — The strictly typical state calls for a general resem-
blance between the form of the perigone parts and that of the foliage
leaves of the plant which bears them. They sometimes display a keel
corresponding to the mid-rib of the leaf, and as in the leaf, this may
ADHESION
51
be continued into a terminal ])oint. They may be concave, as in Thco-
hroma (Fig. 71); the margin may be toothed and the a})ex tootlied or
fim])riated, as in Siletic (Fig. 72); the toothing of the margin may extend
into a ])imiatifid condition, as in the calyx
lobe of Rosa canina (Fig. 73), and that of
a toothed or fimbriate apex into the cleft
or divided state of chorisis.
The Pappus. — The peculiarly di\ided
calyx illustrated in Fig. 79, a, is denomi-
nated a rai)pus, and this term has been
extended to all forms of the calyx (Figs.
74 to S3) existing in that family (the
Com positae) and in some others. Fig. 80
illustrates the action of median, as well as
of lateral chorisis, in the development of
a double pappus, the outer circle being
much shorter and different in kind.
The se^•eral forms of perigone i)arts
corresj)onding to those of leaves (see leaf-forms) and numerous inter-
mediate ones not illustrated, should be carefully considered by the
student, as they ha^e a most important bearing ui)on the forms of the
corolla produced by cohesion, which we shall shortly consider.
FiK. 71. ConoMVc petiil of Tlicohronut.
72. FlowtT of .SiVi/K, the i)etals loothod
at apex and bearing a crown at junction
of limb with claw; also a conspicuous
anthophore in base of calyx. 73. Pinna-
tifid sepal of Jiusa.
IS. 76. n.
Figures illustrating forms of the pappus; Fig. 71. Pappus little changed from ordinary superior
calyx-limb. 75. That of Tanareium, reduced to a short cup. 70. That of Absinlhiuiri, practically
obsolete. 77. That of yVycthia, 2 of the calyx-teeth awned. 78. That of Griiidelia, the two remaining
calyx-teeth aristiform. 79. That of Aruica, the ordinary setose form. SO. The double pappus of
£ri(/(To;i, the outer series very short. 81. Plumose bristle from pappus of Lasiopoffon. 82. Scaly bristle
from pappus of Eriosphaern. H',i. Serrate bristle from pappus of Cineraria.
Adhesion. — Both adhesion and cohesion are exceedingly common in
the case of the })erigoiic. The foiiner has already been pretty fully
considered. \Vry rarely is it so coiniilete that there is not at least a
])()rtioii of the parts remaining free. Since the adherent ])arts are
52
THE PERIGONE
alternating, adhesion necessarily involves the ultimate effect of cohesion.
In the case of cohesion extended very high, peculiar effects, often
puzzling to the beginner, are produced, as in the case of Oenothera
(Fig. 29).
Here the calyx, after adhering to the entire surface of the ovary (e),
is continued upward in the form of a long, slender tube resembling a
flower-stem. Inside of this tube the petals and stamens are adnate,
and do not become free until they reach its summit.
Cohesion. — Cohesion, like adhesion, may be partial or complete. In
its slightest forms, with a mere band of union at the base, it may
escape observation, as in the case of the corolla of Lysimachia (Fig. 84).
In such cases a decision is best reached by carefully pulling away the
Fig. 84. Adnate corolla and androecium of Lysimachia, the parts of each coherent at the base only-
87. Completely separating calyptra of Eucalyptus. 88. Partly attached calyptra of Mitranthes.
89. Corolla of Oenothera escaping through a fissure in side of calyx. 90. Corolla of Ayenia, its petals
coherent at summit only. 91. Completely coherent petals of Ipomoea, leaving the margin merely
sinuate.
corolla. If there is a union, however slight, the corolla may thus be
removed as one body. Agglutination will occasionally cause an appear-
ance of cohesion, but upon applying the test here specified, the parts
will be found to separate readily, without the tearing of any tissue.
The Calyptra. — A peculiar and extreme form of cohesion is that in
which the sepals refuse to separate even at the apex wdien the flower
expands, and the calyx is torn loose from its basal attachment, falling
entire as a Calyptra, as in the corolla of Eucalyptus (Fig. 87), or remain-
ing attached at one side as in Mitranthes (Fig. 88). A modification of
it permits the remainder of the flower to escape through a rent in the
side, as sometimes in the case of Oenothera (Fig. 89). Very rarel}^
cohesion exists at the apex only, a remarkable instance being the corolla
of Ayenia (Fig. 90).
SPECIAL FORMS OF CALYX AND COROLLA 53
Terms Indicating Cohesion or its Absence.- — When tlic ])ctals are dis-
tinct the coroUa is said to he l^lenther()i)etaloiis or Choripetalous. The
ol(K'r hut less desirable term is Polypetalous. When they are coherent,
the corolla is said to be Gamopetalons or Synpetalous, the older and
less desirable term being Monopetalons. Corresponding terms lor the
calyx are Eleiitherosepalous, Chorisepalous, or Polysepalous, and
Gamosepalous, Synsepalous, or Monosepalous. In the gamopetalous
and gamosepalous state the parts cease to be designated petals and
sepals, and are known respectively as Corolla-lobes and Calyx-
lobes.
The relative altitude to which the cohesion is carried is indicated
by special terms. When existing at the base only, the circle is said to
be parted (Fig. 84) ; when extending about half-way up, as in Solainim,
Cleft (Fig. 92) ; when still farther, but yet leaving a considerable portion
ununited, as in Spigelia, Lobed (Pig. 97), and when having only traces
of the parts ununited, Toothed (Fig. 102). A peculiar form is that in
which the position of the parts is indicated by a mere waving irregular-
ity of the margin, as in the flower of Lpomoea (Fig. 91), which is then
said to be Sinuate or I 'ndulate. The student must not fail to discrim-
inate between the entirely different senses in which these terms are
here used, in reference to the entire calyx and corolla, and as used
previously in reference to the margin of a single part thereof.
Special Forms of Caljrx and Corolla. — We must next consider certain
specific forms of the calyx and corolla as wholes, which are of \ery
great diagnostic value. That the form of a gamopetalous corolla is
determined by the form of the ])etals of which it is composed is readily
seen by comparing Figs. IS and 98. In Fig. 18 we have a j)etal with
a long, slender claw and a broad limi). Several such petals united by
their edges must yield a corolla with a broad border supported upon a
long tube; just sucli a form is that represented by Fig. 98. Similar
results are shown in Figs. 97 and 99, and it is not difficult, on examining
these figures, to imagine the exact form of the component parts. In
Fig. 9;^ we have a union of somewhat broader petals, while those of Fig.
MY.] were so ^■ery sliort and broad as to have resulted in a saucer-slia])ed
corolla.
Although such characteristic forms are most numerous among the
coherent class, tiiey are not wanting among those in which cohesion
does not exist. Sometimes a non-coherent corolla will necessarily
assume such a form through the restraint exercisetl by coherent sepals.
At other times the form is entirely independent of such restraint.
54 THE PERIGONE
The Tube, Throat, and Limb. — In such corollas and calyces as are
represented by Figs. 97 to 99, the narrow portion is denominated the
Tube and the broad portion the Limb. When the change from tube to
limb is not abrupt, there will be an intermediate portion, as displayed
at h in Fig. 94, called the Throat. Less frequently this term is ap])licd
also to the delimiting circle between the limb and the tube when these
do meet abruptly. Occasionally distinct contraction instead of a dila-
tation will be found at the throat, as very frequently occurs in other
parts of the tube (Fig. 100).
The Margin. — The terminal boundary line, including all its extensions
and intrusions, is called the Margin, The margin may intrude partly
or quite to the tube, so that the cohesion may include none or the whole,
or any part of the throat, or of the limb.
Special Terms Indicating Form. — The terms regular and irregular
apply to lobes precisely as though they were distinct sepals or petals
and to the united portions as well as to the lobes. Some of the terms
applicable to the forms of the gamopetalous corolla (and, of course, to
the gamosepalous calyx) refer to its entire body, while others refer to
its several parts. The former class, and among them those which are
regular, will be first considered.
The term Cylindrical is self-explanatory. If nearly cylindrical, it is
called Cylindraceous. Such shapes are shown in Figs. 29 and 99. If
such a one is manifestly angled, as in the calyx of MimiiJus (Fig. 94),
it is Prismatic, and the same is true of other tubular forms. If the
entire body flares regularly (Fig. 97), or if there is such a flaring portion
upon a cylindrical tube, it is called Infundibular or Funnel-shaped.
The less broadened infundibular forms are called Trumpet-shaped, as
in the honeysuckle. If the flaring portion or limb is flat, or nearly so
upon a cylindrical or cylindraceous tube, it is called Ilypocraterimor-
phous, H\^ocrateriform, or Salverf-orm, as in the flower of the coffee
(Fig. 101). A corolla which is bell-sha])ed is called Campanulate
(Fig. 93). Of this there are two sul)-forms, the Open (Fig. 91) and the
Contracted (Fig. 95). The term Globular or Globose is self-explanatory.
It may be specified, however, that the mouth must be small and with
no conspicuous limb, or with the limb turned back flat against the
body. Approaches to the globular form are called Sub-globular or
Globoidal. Other related forms are the Ovoid or egg-shaped and
oblong. A somewhat globoidal form, with conspicuous recurved
margins, is Urceolate or Urn-shaped (Fig. 102). Of the broader or
more widely expanded forms, the campanulate develops outward into
TERMS I X 1)1 ( 'A TI Xd I RREd ll.A RI T Y
55
tlic llcinisphcrical and the C'ratcritorin or Sau('('r-.slia])ccl, as in the
Kalmia (Fig. 103). When still more flattened out it becomes Rotate
or Wlieel sha])ed, as in the SoIa}iiiin (P^ig. 92).
A ganiopetalous corolla sometimes has a fissure on one side extending
nearly or entirely to the base as in the Lobelia (Fig. 9G). When in
addition the corolla or the split portion of it loses its tubular form,
becoming flattened out, it is called Lignlatc or Strap-shaped, as in the
Dandelion (P^ig. 104).
Special Formx of I'triyoiie. — Fig. 92. Rotate corolla of Sola/mm, with connivent anthers. 93.
Campanulate corolhi of Campanula. 91. Prismatic calyx and bilabiate, personate corolla of Mimulus:
a, the tube; b, the throat; c, the lower lip; d, the palate. 95. Contracted campanulate corolla of
Leucolhoe. 96. Fissured corolla of Lobelia. 97. Infundibular corolla of Spiorlia. 98. Hypocrateri-
form corolla. 99. Cylindrical corolla. 100. Hypocratcriform corolla of Erhiles with portion of tube
constricted. 101. Hypocratcriform corolla of coffee flower. 102. Urceolato corolla of Pemettya.
103. Crateriform corolla of Kalmia. 104. LiKulate corolla of Taraxacum.
Accuracy Required in the Use of Terms.— The applicability to the tube
and limb separately of many of the terms here applied to the entire
corolla is apparent. It should be noted, however, that very detailed
descriptions of these res])ective parts, as well as of the throat, with
specification of any irregularities and marks, are often imperatively
demanded. This is es])ecially true of the florets of the Compositae,
where such cliaraetcrs, although \'ery slight, fr{>(|ueiitly serve for si)ecific
distinction.
Special terms for forms resulting from the possession of a])pendages
will be considered hiter.
Terms Indicating Irregularity. — Terms indieating irregularity will next
be considered, commencing with those ai)plicable to the entire body.
Either the base or the mouth is ()bli{(ue when a plane transecting
it is not at right angles to the lloral axis. The body is declined (Fig.
56
THE PERIGONE
107) when, either with or without any manifest curve, its axis is turned
from the perpendicuhir, so that it rests more or less against one side of
the cal^-x. It may be Straight or Curved, and the curvature may be
Simple (Fig. 99) or Compound as in the Sigmoid calyx of Aristolochia
(Fig. 106). When dilated upon one side only it is Ventricose, as in
some species of Salvia (Fig. Ill), or, if the swelling is small and prom-
inent, Gibbous (Fig. 107, a). When the swelling is carried downward,
so as to form a sac, as in Cypripediuvi (Fig. 112, a) it is called Saccate.
When the dilation is directed upward, so as to form a hood, as in Aconite
(Fig. 108, a), it is called Cucullate or Galeate, and when the hood is
//^ //s
//£ m
Fig. 105. One-lipped corolla of Dinoseris. 106. Sigmoid-curved calyx of Aristolochia. 107. Corolla
of Achimenes, the mouth oblique, the base declined and gibbous. 108. Galeate upper petal of Aconite.
109. Personate corolla of C/ieZone. 110. Papilionaceous corolla of La^^2/r«s. 111. Ringent and gibbous
corolla of Salvia. 112. A saccate lower petal of Cyprip^dium. 113. Auricled calyx of Nicandra.
114. Dorsal spur on petal of Myrmephytum. 115. Long-caudate petals of Theobroma.
compressed laterally and much enlarged proportionately to the size of
the body it is called Cristate. Most of these terms are also applicable
to a single lip of the form next to be considered or to a petal. When
one or more of the lobes of a corolla are separated by a deeper sinus
than those of the others it is called Labiate or Lipped. If the fissure
proceeds entirely across the corolla, cutting off the lower portion, it
becomes One-lipped (Fig. 105). Otherwise it is Bilabiate or Two-lipped
(Fig. 111). The two lips are denominated respectively the Upper or
Inner (a), being that which is nearer the stem of the plant when the
flower and its stem are standing erect and without any twisting, and
THE AURICLE 57
the Lower or Outer {h). It is always of iiii])ortaiice to note the number
of lobes inchuled in each Hp, in doinf; which the student may be misled
either by chorisis, one or more extra lobes making their appearance,
or, far more frequently, by cohesion, two lobes coalescing into one so
as to simulate suppression. Two forms of the bilabiate corolla are
commonly recognized — the Ringent in which the lips stand widely
apart (Fig. Ill), and the Personate, in which the mouth is occluded
(Fig. 109).
Several distinctive titles are applied to flower-forms which are
characteristic of large and important families or sub-families, the
Labiate being one. Another is the Papilionaceous, in reference to its
simulation of the form of a butterfly (Papilio), as in the common Pea
(Fig. 110). The five petals are as follows: Two (a) are more or less
coherent by their lower edges to form the Body or Keel; two others (6)
are denominated the Wings; the fifth (c) is large, broad, and commonly
reflexed so as to ajjpear erect, and is called the Vexillum or Standard.
Caryophyllaceous and Cruciferous Corollas. — Special names have also
been applied to the choripetalous corollas characteristic of the pink
and mustard families. The former, the Carophyllaceous corolla (Fig.
72), consists of five petals, each with a long, slender claw extending to
the summit of an elongated calyx, and there expanding abruptly into
a broad limb. The other, the Cruciferous corolla, has four petals, of
similar structure and form, so placed as to present the form of a cross.
Appendages. — Appendages to the perigone, while less numerous and
varied than in the case of the other organs, call for our careful attention,
as they sometimes occasion false interpretations. In the sense in which
the term is here emi)loyed, we do not refer to hairs and similar out-
growths which modify the surface of the parts, and which pertain
equally to other parts of the ])lant, but to developments which pertain
distinctly to the flower, modifying its structure or functions, or com-
monly both, in some important way.
The Auricle. — In Nicandra (Fig. 113) we observe a slight appendage
at the base of the calyx-lobe on either side and directed downward.
Such an appendage, because of its resemblance to the lobe of the ear,
is called an Auricle. Its appearance is somewhat exaggerated in this
case, owiiiu: to tlu- fact that the calyx is inflated. Smaller auricles are
seen at the base of the calyx of Lobelia (Fig. 1 ");'>) . A similar a])pendage
is sometimes directed upward, and by its union with the contiguous
one forms an organ exactly resembling an intermediate or false sejial,
as in the Strawberry (Fig. 30). Such ai)pendages, which undergo
58 THE PERIGONE
considerable variation in form and consistency, may or may not be
stipular in their natnre. Marginal teeth extended into conspicuous
appendages have already been referred to.
The Cauda or Tail. — Sometimes the apex is similarly prolonged into a
Cauda or Tail, an extremely exaggerated form of which is sometimes
seen (Fig. 115).
The Awn. — An apex extended into an acute, stiff", slender point is
an Arista or Awn (Fig. 78, a). An awn sometimes emanates from the
producing organ at the back, instead of at the apex, and is then called
a Dorsal Awn.
The Horn.— An awn-like body which is hollow is a Cornu or Horn
(Fig. 150, a).
The Spur. — A horn-like appendage extending downward is called a
Calcar or Spur (Fig. 65). The spur may also be dorsal (Fig. 114). All
of the appendages noticed above may be found upon either calyx or
corolla.
The Fornicate Corolla. — Sacs to the corolla are sometimes intruded,
as in Mertensia (Figs. 118 and 119), instead of extruded. The corolla
is then said to be Fornicate. Instead of sacs there may be longitudinal
folds, as in some species of Gentian.
The Palate. — When a single large sac occludes the mouth of a bilabi-
ate corolla it is called a Palate (Fig. 94, d).
jNIany appendages such as we have noticed are secretory in function
and they may even be glandular in form. Doubtless the various
secretions are characteristic, and might, in pharmacy, in exceptional
cases, be utilized for diagnostic purposes, but the attempt has never
yet been made.
The Corona or Crown. — Lastly, we note what is perhaps the most
important, as it certainly is the most striking and interesting, of the
corolla or calyx appendages — namely, the Crown. The crown is an
outgrowth, more or less membranaceous, from the face of the perigone.
Its morphological nature is not understood or agreed upon, and is
probably not the same in all cases. It may be a mere abnormal product
of median chorisis, or it may be the homologue of the ligule of certain
leaves, hereafter to be considered (see h in Fig. 4G5, .1), the latter being
regarded as a normal and morphologically distinct part. When the
crown develops from a petal with a distinct narrowed basal portion,
which may be assumed to correspond to the petiole of the formative
leaf, it usually develops from or near the point where this is joined
to the broader portion (Fig. IS). The crown becomes very important
PRAEFLORATION
50
ill classification in such families as Passifloraceae (Fij?. 110, a), Asclc-
])iadaccac, and AiiKiri/llidaccac (Fif?. 117, a). A ring of intruded folds
at the throat (Fijj;. 119) is often, jjcrliaps incorrectly, called a crown.
It is sometimes very difficult to deterniine whether the crown is an
appendage of the corolla or of the androecium.' Its adhesion is some-
times to the androecium and not to the corolla, and sometimes to both.
In some species of Passi/lom which have no corolla, the attachment
is to the calvx onlv.
//a
Fig. IIG. T,i>nKitutlinal section, throviKli flower of Passiflora oxliihiting orown at a. 117. Flower of
Narcissus exliibiting a. large crown at a. US. Flower of Myoyotis. 11',). The same opened to sliow
folds in throat.
Praefioration. — The arrangement of the ])arts of the perigone in the
bud yields some of our most important diagnostic characters as dis-
tinguishing families, sub-families and genera, and has been the subject
of elaborate classification. The demands of pharmacognosy, however,
call for attention to only the princii)al types of Praefioration or Aesti-
vation. The three principal types depend upon the fact that the com-
bined breadth of all the ])arts of a perigone circle must (1 ) be insufficient
to enclose the i)U(l, in which case ()])en s])accs must be left between
their margins {Rr.srdd) or the summit must be left uncovered (the calyx
in P^ig. 120), the form in either case being called Open; (2) it must be
exactly sufficient to enclose it, the edges then meeting exactly, with
nothing to spare and the form being called Valvate (Fig. 12;), the calyx);
or {'.]) it must be excessive, in which case the excess may be dis])()sed
of in one of several ways. In one, the parts, after nuH-ting s(iuarely,
ar<' uniformly turned straight outward (Fig. 121), the form being
called Valvate Reduplicate. In another, they are turned straight
inward, the Valvate Iiiduplicate form (Fig. 122). They may even be
60
THE PERIGONE
rolled inward, the Involute form. When lapping the one o^•er the
other they are Imbricate (Fig. 123, the corolla). Here it is important
to note whether the overlapping is from right to left, Dextrorse (Fig.
125), or the reverse, Sinistrorse (Fig. 124). In determining this point,
the relations can best be understood by imagining the flower as a man,
his feet in the direction of the torus and his hands representing the
petals. To be dextrorse, his right hand must be covered by his left.
In other words, the terms "right" and "left," in this position, signify
right-covered and left-covered, not right-covering and left-covering.
/Z3. /2&
Fig. 120. Bud of Ipomoea with open calyx and convolute corolla. 121. Transverse section through
valvate reduplicate calyx of Hibiscus. Fig. 122. The same, valvate-induplicate calyx of Clematis.
124. Sinistrorse imbrication of corolla-lobes of Lochnera. 125. Dextrorse imbrication of corolla-
lobea of Echites.
Petals, sepals, or stamens are occasionally rolled vertically down-
ward from the apex, this form being called Circinate. Occasionally we
find the petals folded and doubled in an irregular manner, the Crumpled
or Corrugated form of praefloration. A number of terms are called for
by the peculiar conditions of the gamopetalous form. Economy of
space is here commonly secured by longitudinal folding, the Plaited
form. Vertical shortening is often secured by twisting, the Convolute
form (Fig. 120, the corolla). In this case it is important to determine
the direction of the contortion as dextrorse or sinistrorse, in the same
way as that of imbrication.
Other details as to the precise mode of overlapping are frequently
worthy of note.
In determining the form of jjraefloration, care must be taken to
select a well-formed bud.
The Mixed Form. — The praefloration may be mixed, as in Oenothera,
where the parts^^are valvate at the base and slightly imbricate or redu-
plicate at the immature apex. At the best, intermediate and perplexing
forms will be encountered.
DURATION 61
Duration. — The duration of the perigone, especially of the calyx,
is frequently of considerable importance from the standpoint of phar-
macognosy, although in general not so. When a part falls away at,
or very shortly after, expansion it is Caducous. When lasting about
a day, and then either falling or i)erishing upon the flower, as in the
poppy, it is Fugacious. When lasting longer than a day, but falling
soon after fertilization, it is Deciduous. When remaining and retaining
more or less of its normal appearance for some time after fertilization,
it is Persistent. When so remaining, but in a withered condition, it is
Marcescent. These definitions assume that fertilization takes place
normally. If this be artificially prevented or deferred, the freshness of
a corolla is often very greatly })rol()nged. (See Fertilization.) Impor-
tant facts relating to the Accrescent calyx of the fruit will be i^resented
when the latter is discussed.
Some very interesting facts concerning characteristic movements
of the corolla, its sleeping and awakening and other habits, should be
sought in general works on botany.
CHAPTER V
THE ANDROECIUM
Review. — It has already been shown, in considering the general
nature of the flower, that in at least a large part of the flowering class,
the androeciiim typically consists of two stamen-circles, the stamens
of each isomerous with the parts of the other circles, one standing in
front of each petal and sepal, that each stamen is entirely free and
distinct, and of characteristic form and structure (Figs. 12 and 14).
We have also pointed out some of the forms of deviation due to
duplication, suppression, adhesion, and metamorphosis. To these the
following general remarks may be added.
Sterile Filaments and Anthers. — When an anther, still present, has
lost its function, it is called a Sterile or Imperfect Anther. When the
anther has become suppressed, but the filament remains, the latter is
called a Sterile Filament. Either of these is called a Staminodium.
One or more complete circles of sterile filaments, changed or not by
metamorphosis, may be mistaken for a crown or a disk (Fig. 38).
Adhesion of the stamens to the corolla, or even to the ovary, may
include only one circle, the other circle being entirely free, or they may
be adnate in different degrees (Fig. 44).
Terms Indicating the Number of Stamens. — Before discussing other
and specific points of variation, we shall consider the typical organ
more in detail. The number of stamens in the androecium is indicated
by joining the appropriate numeral to the suffix "androus;" thus,
Monandrous, Diandrous, Triandrous, Tetrandrous, Pentandrous, etc.
These terms do not necessarily indicate the numerical ])lan of the flower.
When the number is 20 or more, the term Polyandrous or Stamens
Indefinite is commonly employed.
Color. — In color, the filament is commonly white or whitish, and
the anther yellow; but this is not an absolute rule, as the latter is often
blue, brown, black, or otherwise colored.
Construction of the Anther. — There are several distinct forms of attach-
ment of the anther to its filament which are characteristic of larger or
smaller groups. Its origin from the leaf assumes that each theca
corresponds to a vertical half of the leaf from which it has developed.
ATTACHMENT OF THE ANTHER
63
and the production of a sccoiHlan- or "false" i)artition separating each
theca h)ngitudinally into two locclli. This inipHes a four-h)cellatc
condition of all anthers (Fig. K)S). Ordinarily this condition is not
permanent, the false septa more or less completely (lisa])i)earing after
the formation of the pollen, leaving the mature, antlier two-celled, or
this condition is brought about in other ways.
Attachment of the Anther. — The Adnaic Form.— It is furthermore
assumed that the filament is normally continued along the back of
the anther in the relation of the midrib of the formative leaf. This
form of attachment is called Adnate (Fig. ]2()).
Fig. 126. Adnate anther of Magnolia. 127. An incumbent anther. 128. Twisted anther of Ceiba.
129. Versatile anther of Oenothera. 130. Innate anther of Sangumaria. 131. Reniform confluent
anther of Malva. 132. Horizontal confluent anther of Pcnlslemon. 133. Sagittate anther of Taber-
naemontana.
Iiicinnhctit Form. — It ma>' be attached only at some ])oint u])()n the
back (I)orsifixed). Of this there are two forms. In one (Fig. 127) the
anther is rigidly fixed, its lower portion close to and ])arallel with but
free from the upper portion of the filament, the Incumbent form.
]'ers(iiUe Form. — In the other, it moves freely upon the pivotal
l)()int of attachment (Fig. 129), the Versatile form. Rarely the anther
is wrapped or twi.sted about its filament (Fig. 128).
Innate Form.— Thv continuation of the filament, instead of being
along the back, may be centrally up through the base and between the
thecae (Fig. 130), the Innate form.
SiiKjiiidtc Form. — The lower ])ortions of the thecae may be separated
from one another and from the connective (Fig. 13.3), the Sagittate form.
Reniform (inti Ilor/'jnifdl Form.^-. — The sagittate condition is some-
times extreme, the antliers becoming more or less reiiifonn (Fig. 131)
or semicircular, or tlicy may e\fii become liori/.ontal I l''ig. 132). This
64 THE ANDROECIUM
is to be distinguished from the form which is horizontal by versatility
(Fig. 129), by the presence in the latter of the two cells side by side,
in the former, end to end.
Extrorse and Introrse Attachments.- — Rarely the adnate form will
possess the connective upon the inner side (next the pistil), when it is
Extrorse by Attachment, in the normal form being Introrse.
Forms of the Filament. — Besides these variations in the relation of
filament and anther, each is in itself subject to certain modifications,
some of which will be discussed in connection with appendages and
exaggerated growth. The general form of the filament is subject to
much variation which, being characteristic in a given species or genus,
requires specification. When cylindrical, either of uniform thickness
throughout or regularly tapering, it is Terete. When considerably
thickened toward and at the summit, so as to be club-shaped, it is
called Clavate. When flattened it is Complanate. Laterally Com-
planate is so flattened that the edges point toward and from the gynae-
cium, the broad sides to right and left. Dorsally complanate has the
edges pointing to right and left, the broad sides facing toward and from
the gynaecium. A dorsally complanate filament may have a sharp
ridge or keel running along its back, when it is called Carinate or Keeled.
If the ridge is less sharp and prominent it is Costate or Ribbed. It
may, upon the other hand, bear a groove, when it is called Channelled.
Rarely a filament is Triangulate in cross-section, or otherwise prismatic.
When tapering from a broad base to a rather acute apex, and rather
short, it is Subulate or awl-shaped. When very slender or thread-
shaped, it is filiform. When even more slender so as to be hair-like,
it is Capillary.
Forms of the Anther. — The principal forms of anther are oblong, oval,
globular, reniform, quadrangular, or linear, and the base or apex may
be truncate, rounded, obtuse, acute, or pointed. An anther is occa-
sionally doubled upon itself, when it is styled Sinuous (Fig. 139). It
may even take the form of a horizontal ring (Fig. 134). This condition
is sometimes preceded by the loss of one theca. In any case of curva-
ture, even slight, of the anther, the same is characteristic and of value
in classification, as exemplified in the vast genus Solanuvi, where
attention to this character is well nigh indispensable. The filament is
also sometimes variously curved or reduplicate, and this condition may
be permanent or only temporary during the early stage of the flower,
as in Ardostaphylos (Fig. 145), where the powerful elasticity of the
filament assists in expanding the corolla.
J.\TR()/iSK A\D EXTliOR>SK DI'JII ISCKXCK
05
Development of the Spores. — Inside of the tlicca, develop certain
large cells, in rows, the Spore INIother Cells, each of which, by t)\ice
dividing, produces a Tetrad of four pollen-grains. Ordinarily the wall
of the mother-cell mostly (lisa])i)ears and leaves the grains separate and
mobile, while in other cases they cohere in the tetrad or in a cluster
of tetrads.
Pollinia and PoUinaria. — Large clusters are called Pollinia or Pollen-
masses. The entire contents of a theca may form one pollinium (Fig.
135), or they may be divided into several (Fig. 140). A cluster of
pollinia, like the last, is called a Pollinarium. The number of pollinia
Fig. 134. Ring-formed anther of Cyclanthera. 135. Pollinium of Asclepias. 136. Dorsal dehiscence
in anther of Hyoscyamus. 137. Dehiscence by apical pores in Menzicsia. 138, Dehiscence by valves
in anther of Sassafras. 139. Sinuous anther of Sicyos. 140. Pollinarium of 4 pollinia in Ponthiera.
141. Marginal dehiscence in anther of Convallaria. 142. Ventral dehiscence in anther of tomato.
143. Dehiscence by apical pores in anther of Cassia. 144. Peculiar ventral pores. 145. Apical pores
becoming basal by inversion of the anther in Arctostaphylos.
in a theca is of much diagnostic importance in tlie Orchidaceae, The
characteristics of the individual ])()llen-grains are of the utmost value
in pharmacognosy, as well as in classification (as, for instance, in the
Acanthaceae) , and arc discussed in works on histology.
Dehiscence of the Anther. — ^We must next consider the structural
provisions for permitting the escape of the pollen from the thecae or
locellae. This is commonly by splitting, called Dehiscence, along a
longitudinal line upon each theca, called the Suture. If the suture is
at the back of the anther, as in Ilyoscyamns (Fig. 136), the dehiscence
is called Dorsal. If upon the face, as in the tomato (Fig. 142), Ventral;
if upon the i^^h^(.\ as in Coiirdllaria (Fig. 141), ^Marginal.
Introrse and Extrorse Dehiscence. — This suture may face the gynae-
cium, when the anther is Introrse by Dehiscence, or away from it,
5
66 THE ANDROECIUM ^
Extrorse by Dehiscence. It does not follow that an anther introrse or
extrorse by dehiscence is the same by attachment.
Confluent Sutures. — In the sagittate-horizontal anther the sutures
of the two thecae often become continuous, the Confluent form (Figs.
131 and 132).
Dehiscence by Pores. — Small orifices, called Pores, frequently exist at
the apex, as in Ca.s-.sia (Fig. 143), more rarely at the base. The most
scrupulous care must be taken to determine the exact direction in which
apical pores look. In some cases, as in Solanum, a slight difference
will possess specific importance.
Dehiscence by Valves. — A less common form of discharge is by A^alves
(Fig. 138), the common form for the four-locellate anther. Special
mechanical contrivances for aiding in the discharge of the pollen are
of great interest and will be mentioned under Cross-pollination.
Cohesion. — Cohesion is responsilile for quite as great and important
modifications of the androecium as of the perigone. Here, as there, it
may be complete, or, beginning at either apex or base, it may stop at
any point. Fig. 84 displays the dilated bases of the filaments of
Lysimachia lightly coherent, the detection of the condition calling
for the same keen inspection as in the case of the corolla. In Guarea
(Fig. 147) the union is seen carried to the anthers, but these left
distinct.
Adelphism. — Coherent filaments are styled Monadelphous when all
united (Fig. 147), Diadelphous, when there are two groups, even though
one of them contains but one stamen, as in Glycerrhiza (Fig. 146),
Triadelphous when three, and so on. It must not be lost sight of that
the terms are applied similarly, w^hether the iniion is progressive, the
result of cohesion as in this case, or that of incomplete chorisis, as in the
Tilia (Pigs. 34 and 37) and Psorospermum (Fig. 38), though its classi-
ficatory value is very different in the two cases.
The Stamen-column. — The term column, previously explained, is
changed to Stamen-column for monadelphous stamens.
The Ssmandrium. — The stamen-column is ordinarily hollow, contain-
ing the Gynaecium; but when the flower is staminate, the column is
solid, and called a Synandrium.
When, as seen in Fig. 92, the anthers come together but do not actually
cohere, they are called connivent. The cohesion is carried only partly
down the filaments in the squash (Fig. 148), and partly upward in the
Sidalcea (Fig. 149), but in the Asdepias (Fig. 154) it is complete for
the entire organs.
APPEND AGING
C7
Asymmetry and Irregularity. — A lack of symmetry aiul regularity,
actinu' sci)arately or tout'tluT, is responsible for a number of character-
istic and iinpoi-tant states of the androecium requiring,' distinctive
terms.
The Didynamous Androecium.- In the o-merous flower of ScidcUarid
(Fii;-. l")!) six stamens are su])pressed and the rcniaininijj four are
irr('<;ulai-, there being a pair of each form. This foi-ni of anch'oeciiim
has received the title of Didynamous. In this case the antlicrs of a j)air
are connivent also.
/J4
Fig. 140. Diadelphous arulroerium of Glycyrrhiza. 1-17. Vertical section lliroiigh flower of Guarea,
showing nionadelphous filaments witli distinct anthers. 148. Cohesion of filaments, incomplete at
base, in flower of squash. 149. The same, incomplete at summit, in flower of SiV/afcca. 150. Vertical
section through flower of Asdepias showing coherent filaments and anthers, with appendages to crown
in form of horns. 154. Winged androecium of same. 151. Didynamous androecium of Labiatae
152. Androecium of Eupatorium, the anthers coherent, the filamenta distinct. 153. Monadelphous
filaments and anthers of Lobelia.
The Tetradynamous Androecium.^In that of the IMustard (Fig. 33),
two of the stamens Iuinc each by chorisis become converted into two,
these differing in length from the undi\i(led pair. 'J'his form is styled
Tetraflynanions.
Appendaging. No other subject connected with the androecium calls
for such close and discriminating attention in connection with pharma-
cognosy as the i)roducts of exaggerated growth and enation. No
portion of the androecium is free from their effects, which ai)ply equally
to it when adherent or coherent, free or distinct. The simplest form
of appendage to the filament is that of sti])nloid a])])endages to the
68
THE ANDROECIUM
base, called Petaloid when assuming the form of a petal, as in Fig. 155
A similar appendage may stand in front of a stamen. One standing in
front of a stamen group has been shown in Fig. 37. Appendages may
be developed at a higher point in other cases. Appendages in the form
of teeth or hairs are very common.
Modifications of the Connective. — Modifications of the connective are
numerous and remarkable. The thickening of its entire body, equally
or unequally, produces such appearances as are seen in Figs. 15G, 157,
and 159. Or the extension may result in elongation either above or
below the thecae, instead of in broadening.
/SS. 2S6 ISZ IMJ60
Fig. 155. Petaloid appendage to filament of Chaetostoma. 156, 157, and 159. Anthers with the con-
nective broadened so as to separate the thecae. 158. The same with the broadened connective forked.
160. Stamen with connective extended between the apex of the filament (a) and the base of the anther
(6). 161. The same, with an appendage at base of connective. 162 and 163. The appendage with
scarcely any elongation of connective. 16-4. Forked connective of Salvia, each branch bearing one of
the thecae.
Basal Appendages. — If the extension is downward, it will lead to an
apparent jointing of the filament (Fig. 160), the space between a and b
being such a downwardly produced extension of the connective. A
slight bulbous enlargement at the base may be modified into the most
grotesque forms, as shown in Figs. 161 to 163. Such appendages, in
every detail of number, form, position, and direction, are characteristic,
and in a family like the Melastomaceae, from which most of the above
illustrations are taken, possess generic value. Instead of elongating
as a single body, the base may* apparently divide longitudinally, through
extreme broadening, resembling a forked filament, one theca borne on
each branch (Figs. 158 and 164.)
One-celled Anthers. — When one of the thecae then becomes suppressed,
its connective branch remaining (Fig. 165) or even disappearing (Fig.
166), one of the forms of the one-celled anther results. Another form
is produced by simple abortion, without any such modification of the
connective, or it may result from the disappearance of the connective.
APPENDAGES TO THE STAMEX COIAMX
G9
Dorsal Appendages.— Instead of the base, tlie back of the connective
may l)e api)cii(Ia<;c(l. It may become expanded into a disk-like form
over the backs of the thecae, as in Gratiola (Fig. 1()7). The backs of
the anthers may be excavated to receive it, as in Aloe (Fig. 108), or it
may be ap})en(higed in any other direction.
Apical Appendages. — Appendages of any form may devek)p at its
ai)cx. In tlie Compositae these are frequently triangular, as in Eupa-
toriuvi (Fig. 109, a), or lance-shaped. In the Asariim (Fig. 170) it is
an awn, while in the Violet (Fig. 171) it is sail-shaped. Sometimes
it is formed like a feather (Plumose).
Fig. 165. Forked connective, one of the thecae aborted. IGG. The same as in Audibertia, with one
of the branches aborted. 167. Anther of Gratiola, the connective expanded into a saucer-shaped disk.
168. Anther of Aloe, the connective hollowed to receive the filament. 169. Anther of Eupatorium,
the connective bearing a terminal appendage. 170. The same, as in Asarum. 171. The same, as in
Viola. 172. Anther of Vaccitiium, the thecae extended into awns and bearing also dorsal awns. 173.
Monadelplious filaments of Alternanthera bearing fimbriate appendages in the sinuses.
Appendages to the Thecae. — It remains to be pointed out that the
thecae themselves may be similarly appendaged at any part. Fig. 133
displays caudae, or tails, which are found in a great variety of forms.
In Fig. 154, a, Alae, or wings, are illustrated. Dorsal spurs or claws
(Calcaria) frequently occur and are also often borne at the top. Apical
awns to the thecae, forked and pore-bearing at the summit, as well as
dorsal awns, are also shown in Fig. 172.
Appendages to the Stamen-column. — The stamen-column itself is
subject to reinarkai)le and characteristic appendaging, with or without
connection with an adnate disk. Ordinarily, the summit of the stamen-
tube terminates at the beginning of the distinct i)ortion of the stamens,
but sometimes, as very generally in the Amaranthaccae (Fig. 173), it
is continued ui)ward in the sinuses of the anthers, and this j)()rti()ii may
be lobed and appendaged in the most beautiful manner.
Stamens which extend beyond the margin of the coiojla are called
Exserted or Plxsert. This term is also ai)plieable to any organ which
projects beyond the perigone.
CHAPTER VI
THE GYNAECIUM
Gymnospermous and Angiospermous Gynaecia. — Two distinct types
of the gynaecium respectively characterize the Gymnosperms and the
Angiosperms, both of which classes contribute important medicinal
plants. What has been said of the gynaecium in our consideration of
the general nature of the flower, pertains wholly to the latter class. A
few words concerning the former may be written before taking up our
detailed study of the latter.
The Gymnospermous Pistil. — The essential character of the gymno-
spermous pistil is illustrated in Fig. 174. This consists in its not being
shaped into an enclosure for containing the ovules. In the form here
figured there is no progress toward
such a condition, the carpel remain-
ing more or less fiat and bearing the
ovules upon its surface; but in the
progressive forms there is a cavity,
which, however, is never completely
enclosed. A high development of it
is found in the Taxus or Yew (Fig.
175), in which the cavity is deep and
Fig. 174. Entirely plane gymnospermous OpCU Ouly at the Very apCX. The
pseudo-cavity of the gymnospermous
carpel is never divided. It is evi-
dent that no true style or stigma can exist in this class of plants,
although it must be understood that there is an organ performing the
same function of providing for the germination and growth of the
microspore, the possession of such an organ being the one distinction
between the flowering and flowerless plants.
Review. — It has been shown that the gynaecium of Angiosperms,
except in those rare cases in which a central appendage of the torus is
projected u])ward, occupies the center or summit of the flower; that it
consists of one or more carpels or carpophylls which may be all coherent
into a single ])istil, the Syncarpous, Gamocarpous or Compound Pistil
(Fig. 2 IS, etc.), or may each form a separate pistil, the Apocarpous,
carpel of Pinus. 175. Cup-shaped gymno-
spermous carpel of Taxus.
METHOD OF KXAMIXATJOX 71
Monocarpellary, orSiini)le Pistil (Figs. 219 and 220), and tlint ordinarily
the carpels alternate with the stamens of the adjacent circle. The parts
of the pistil have been defined, and it has been shown that of these the
stipe or thecaphore is rarely present, and that the style is very fre-
quently absent, resulting in the Sessile Stigma. The different forms of
adhesion and its effects, as well as those of suppression and metamor-
phosis, have also been explained. Some additional facts of a general
nature must be considered before taking up the details of this subject.
Method of Examination. — The student should from the outset resist
the temi)tation to seek the characters of the gynaecium in the mature
or immature fruit, because of its more convenient size. While many
of the characters of the gynaecium are permanent, there are others
which (lisai)])ear after the fertilization of the ovules, and still others
which only then make their appearance. The other ])arts of the flower
should be completely stripped oft", this operation being performed under
close and continuous scrutiny, with the idea of detecting any character-
istics of relationship between them and the gynaecium. The latter
should then be carefully examined in situ. An implement should be
passed down between the carpels to determine what degree of cohesion,
if any, exists between them, for this will occasionally be found at the
very base only, and also to determine if there be any adhesion to a
central prolongation of the torus. The details of attachment to the
torus must also be determined and their arrangement considered.
When numerous, the pistils are apt to assume the spiral arrangement,
which has already been noticed in referring to the position of floral
l)arts in general. When solitary, the carpel assumes a position to one
side of the axis, thus demonstrating its isolation through the suppres-
sion of the complementary ])arts of the circle. A lack of uniformity,
as indicating abortion of one or more carpels, must be looked for.
When all are uniformly aborted, in the case of flowers which are herma-
j)hro(lite but imi)crfect, this fact will sometimes escajic detection unless
both forms of flower are examined. The color, texture, and surface of
the carjx'Is call for minute exaiiiination in all cases, though there are
no peculiarities of a general nature diil'ering from those of the other
organs. As in the case of the petals, so in that of the carpels, the general
form is determined by that of the foliage leaves; but the form is less
closely preserved and the homology is far less a])])arent here than there,
owing to the far more ])r()foun(l modifications which are rendered
necessary by the j)eculiar functions of the carpels, a consideration which
will further on be seen to a])])ly with special force to tin- fruiting stage.
72
THE GYNAECTUM
Position of the Style.— The position of the style often calls for scrutiny.
It does not always rise, as would be expected, from the summit of the
ovary. One process by which deviation in this particular results is
illustrated by Fig. 17(5, which represents the deeply lobed ovary of
borage, the single style rising from the depression in the center. If,
now, all but one of the parts of such an ovary were to become aborted,
the style would be seen rising more or less laterally (Figs. 177 and
178), or even basally (Fig. 179) from the remaining monocarpellary
ovary. E\'en though the styles remain separate in such a divided
ovary, yet their insertion is necessarily carried toward the base
(Fig. 180).
m. J6'6. m js'S' /m wo
Fig. 176. Deeply 4-lobed ovary of Boraffo. 177. Lateral style on carpel of I'VZ/oresia. 178. The same
in Aslronium, the style almost basal. 179. The same in Alchemilla, the style completely basal. 180.
The same, with none of the carpels aborted. 181. Conical style of Piper. 182. Clavate style of
Helianlhemum. 183. Obconical and prismatic style of Bomhax, with umbrella-shaped stigma. 184.
Obconical style of Chimaphila. 185. Filiform styles of Poederia. 186. Style of Potalia, with large
bulb-like base. 187. Filiform and pilose style of Galopina. 188. Style of Heliocharis, with subulate
branches. 189. Styles showing a tendency to early separation below, while remaining coherent above.
190. Capillary style of maize.
Forms of the Style.— The same descriptive terms as to form already
applied to the filament apply equally to the style and its branches.
Owing to the frequency with which styles are coherent, ribbed, chan-
nelled, or angled forms are common. Fig. 181 illustrates the conical
style of Piper, Fig. 182, an obconical one; Fig. 183, one obconico-
POSITION AND FORM OF STIGMA
73
prismatic; Fig. 184, a clavate form; Fig. 18G, one with a bulbous base.
The style branches in Fig. 185 are filiform; in Fig. 187 they are filiform
and plumose; in P'ig. 190, cai)illary, and in Fig. 188, subulate. Rarely,
styles will be connate above, distinct below (Fig. 189).
Position and Form of Stigma. — The position and form of the stigma
are of very great importance in classification. Its size, as compared
with that in other related plants, is apt to be greater or less according
as the number of ovules to be fertilized varies.
Figures illustrating forms of the stigma
The Linear Stigma. — It has already ])een sliown that while the
stigma is commonly located at or ii(>ar the ai)ex, it may extend either
entire or divided into two lines for a greater or less distance down the
ventral margin of the style, becoming Linear (Fig. 191).
Stigmas Introrsely Located. — If several united styles are separate
at the summit, or ui)i)er j)ortions, their stigmas are commonly borne
upon their inner faces, as in this case, and are frequently, by the co-
hesion of the former in the young condition, secluded from the access
of pollen until a certain time (Figs. 191 and 271). Between the con-
74 THE GYNAECIUM
dition of complete separation and complete cohesion of several stigmas
there are all degrees of division and of lobing of the divisions (Figs. 192
to 195).
The Capitate Stigma. — ^A stigma which is strictly terminal and more
or less spherical, thus resembling a head, is Capitate (Fig. 196).
The Truncate Stigma. — The Capitate stigma is Truncate when it
terminates abruptly in a flat upper surface, as though cut across (Fig.
197).
The Peltate Stigma.— li flattened and attached at the center it is
Peltate (Figs. 183 and 198), and this may be horizontal or oblique, as
in the latter. The peltate stigma may have its margin reflexed, making
it umbrella-shaped (Fig. 199), or upturned, making it cup-shaped, or
Cupulate (Fig. 200), and either of these forms may be lobed (Figs. 201
and 202).
The Laminar Stigma. — A stigma flattened out into a blade-like form
is called Laminar. Several oblique laminar forms are show^n in Figs.
20.3 to 205. Fig. 207 displays the manner in which the stigma sometimes
enfolds the stamen.
The Annular »Sii^7?ia.— Stigmas sometimes possess a ring at or below
the apex, the Annular form, various modifications of which, unlobed
and lobed, are shown in Figs. 210 to 215. Such forms prevail in the
family Ajjocynaceae and are of great value in classification.
Appendages to the Stigma. — The Appendages of the stigma are quite
as numerous and varied as those of the anther. A Plumose appendage
is shown in Fig. 209. Such are common among the grasses. A stigma
(or other organ) is called Penicillate when its ])lumose appendage
resembles a little brush (Fig. 208). In Stigmatophyllon, the appendage
is a little green leaf (Fig. 206).
Terms Indicating the Number of Carpels. — The number of carpels in a
compound pistil is indicated by the use of the appropriate numeral
followed by the suffix "carpellary," thus Dicarpellary, Tricarpellary.
Determination of the Number of Carpels. — The determination of the
number of carpels is of the utmost necessity, but is usually a difficult
task for the beginner, especially if he is not pre\'iously trained in the
art of plant-dissection. The indications may be divided into external
and internal. The latter must be apprehended from the study of
internal structure explained below.
External Indications. — Whenever there is more than one pistil in a
gynaecium, each consists of but one carpel. Complete chorisis of a
carpel, producing more than one pistil, never exists, although it fre-
IX ri'JRNA L IN Die A TIONS
75
queiitly appears so, in the fruit. If cohesion is partial, cxeii tlioiif^h so
nearly complete as to Icaxc a separation represented by a mere lohirig
at apex (Fi<;;. 21G) or dorsum (Figs. 217 and 218), the determination
of the mimber of its carpels is not difficult. It is true that the latter
condition is often complicated by grooving or pseudo-lobing pertaining
to the backs of the indi\i(lual carpels, but such grooves are usually
characteristically different from those separating the carpels. While
the above remarks have been applied especially to the ovary, they may
be applied with equal force to the styles and stigmas. If the exterior
of the ovary bear no indications of the number of car])els, we may
count the styles, or the divisions or apical or dorsal lobes of a style
column, and if those be wanting, then the stigmas or the corresponding
characters of the stigma. It must be noted, however, that complete
Fig. 21G. Ovary of Modiola, the lobes of the summit indicating the carpels. 217. TIk
by lateral lobing in Pentapanax. 218. The same in Tetraplasandni.
or partial chorisis of style or stigma is not at all rare, and care must be
taken to avoid falling into error, by counting mere parts as styles or
stigmas. In such case the number of lobes of each is apt to equal
the number of styles or stigmas.
Internal Indications. — In the case of failure of all these indications to
appear, the internal structure must be studied. For this purpose both
longitudinal and transverse sections must be made. The former should
be so directed as to lay open the inside of a cari)el, and of the latter
there should be three, through the lower, middle, and upper portions
respecti\-ely. In most eases a good li'iis will be sullieieiit to di.sclose
the charaetc-rs, but when insufficient, recourse must be had to the
stage and low power of a comj^ound mier()scoi)e. Further details regard-
ing this process will be found in our chapter devoted especially to the
methods of floral dissection.
76
THE GYNAECIUM
First Plan of Ovarian Structure. — Two distinct plans for the enclosure
of the cavity of the angiospermous ovary are recognized. In the first
(Fig. 219) the margins of one carpel meet each other, and then, by more
or less of an involution, form the placenta with its two rows of ovules
within a single cell. If two or more of such carpels then unite in one
compound ovary (Figs. 221 and 222), each necessarily forms its own
cavity, and there are as many cells as such a pistil has carpels, unless
some modification of structiu'e shall take place, as illustrated below.
Axillary, Axile, or Central Placentae. — In all cases where closed carpels
of this sort unite in a compound ovary, their ventral sides come into
contact, and the placentae are brought together at the center and are
known as Axillary, Axile, or Central.
Fig. 219. Transverse section tlirough 1-celled monocarpellary ovary of bean. 220. The same,
through 2-celled monocarpellary ovary of Astragalus. 221. The same, through upper 2-celled portion
of dicarpellary ovary of Datura. 223. Through lower, 4-chambered portion. 222. The same, through
the 5-carpelled and 5-celled ovary of Vaccinium. 224. Through the 5-carpelled, but 10-celled ovary
of the flax.
Abortion of the Septa. — If the septa between the cells now become
aborted (Fig. 230), the placentae are left free in the center and are
collectively called the Free Placenta.
True and False Septa and Cells. — ^The walls separating the cells of
ovaries constructed upon this first plan, because they consist of the
original carpellary walls, are called "True," as are the cells. When,
as sometimes happens (Fig. 220), a- new septum develops from the
carpellary midrib, extending across to the placenta and separating its
two rows of ovules into two cells, the term "False" is applied both to
the septum and to the cells so resulting. If there be several carpels to
the pistil, and each undergoes this change, it is clear that there must
result twice as many cells as there are carpels (Figs. 223 and 224).
Chambers. — When septa are incomplete, the imperfectly separated
cells which result are called Chambers, and the ovary is said to be
Chambered. Thus the ovary of Datura is completely 2-celled (Fig.
221), but each cell is 2-chambered by partial walls which exist at the
basal portion only (Fig. 223).
BASAL A^'D APICAL PLACENTAE
77
Second Plan of Structure.— Quite a diflVrciit group of appearances
will result from the liiii^lier or more comi)lex form of carpel union, by
which the ])roximate margins of two adjacent carpels meet and unite
(Fig. 225) instead of two belonging to the same carpel. The result of
this form must be a single cavity or a 1-celled .ovary, without regard
to the number of carpels, unless, as in the mustard (Fig. 22(1), one or
more false septa may divide it.
Axillary Placentae. — It has been observed that in all cases of the
first plan of ovarian structure, the placentae will be central. It is
equally clear that in all cases of the second, the placentae must be
formed upon the sides, where the edges of the carpels meet. Such
placentae are called Parietal (Figs. 225 to 229). Such placentae may,
by an extensive involution of the margins, be carried very nearly, or
quite, to the axis (Figs. 227 and 228), but unless cohesion actually
occurs at that p(Mnt they are parietal and the ovary is 1-celled.
;i>26
230.
Fig. 225. The 2-carpeIled, 1-celled ovary of the gentian. 22G. 2-carpelled and falsely 2-celled ovary
of mustard. 227. A 2-carpeIled, 1-celled ovary, its placentae nearly meeting in the axis. 228 and 229.
The same, 3-carpclled. 230. The free central placenta of Primula. 231. A 1-celled ovary with basal
placenta. 232. 2-carpclIed, 1-celIed ovary of Ubolaria, the placentae extended to completely line the
wall.
Modifications of the Placenta. — Some further modifications of the
placenta require our consideration. The free central placenta has
been considered. Such a placenta frequently becomes partly aborted
by the gradual (lisai)])earaiice of its upper portion.
Basal and Apical Placentae. — Tliis process may continue until the
placenta is reduced to a trace at the base (Fig. 231). In other cases it
will be reduced to a trace at the apex (Figs. 235 and 237). Basal or
apical placentae may be Centric or Fccentric. Modifications of these
processes may result in restricting the placenta to any intermediate
point. Upon the other hand, such a j)lacenta may become enlarged and
fleshy. Similar changes may occur in the j)arietal placenta. It may
become reduced to a mere point pre.ser\e(l at the apex, base, or inter-
mediate portion. In the watermelon it becomes enormously enlarged.
78 THE GYNAECIUM
filling the entire cavity with a fleshy, edible mass. In the Obolaria
(Fig. 232) it is laterally expanded to form a more or less complete false
lining to the ovarian cavity. In this position it may remain free or
become coherent, so that, as in this case, the entire face of the ovary
may appear to be ovuliferous. By a subsequent obliteration of a portion
of such an expanded placenta, the remaining portion may be seen to
assume an abnormal position, being occasionally confined to the midrib
itself.
Ovules. — Xumbcr of Ovules. — As has already been pointed out, the
number of ovules is extremely variable and the proportion of them which
become fertilized is little less so.
Position of Ovules. — The position of the ovules is to a great extent
determined by the nature of the placenta, as has already been explained.
It calls for a number of distinctive terms. The two rows of ovules
produced by the two carpellary margins do not always appear distinct,
but may be reduced, before or after fertilization, to one.
Series of Ovules. — A vertical row of ovules is called a series, and ovules
are thus defined as being One-serialled, Two-serialled (Fig. 219), etc.
When there are many series, so that the number is not readily made out,
we simply say that they are Many-serialled (Fig. 227).
Collateral Ovules. — Ovules placed side by side (Fig. 219) are called
Collateral.
Crowded Ovules. — Sometimes no definite series can be made out,
owing to the crowding of many ovules into a small space, as in Obolaria
(Fig. 232). They are then said to be Crowded.
Divergence of Ovules. — Collateral ovules, and, indeed, any ovules
standing together and deviating from a straight line, have a tendency
to turn their foramina away from one another.
Direction of Omdes. — As to the directions, in relation to the ovary,
which ovules assume, they are Erect (Fig. 233) when standing erect
from the base; Suspended (Figs. 235 and 237) when occupying an
exactly opposite position ; Horizontal (Fig. 234) when taking a direction
at right angles to the axis of the ovary; Ascending (Fig. 238) when
directed obliquely upward from some point intermediate between base
and apex; and Pendulous (Fig. 239) when directed obliquely downward
from such a point. When starting as an ascending ovule and afterward
drooping (Fig. 236) an ovule is Resupinate, or when as in Fig. 240,
Recurved-pendulous.
Obscuring of the Position. — An ovule may have its direction obscured
by peculiarities of attachment. Thus, in Loxoijterygium (Fig. 178),
STRUCrURE AND PARTS OF THE OVULE 79
the real base becomes, l)y extreme oblicjiiity, ai)i)arently lateral and
causes an erect ovule to be ai)i)arently ascending. That of Anemone
is suspended, but owing to the same condition a|)])arently only jjcndu-
lous. The terms erect and suspended are after all only relative, as we
can ne\'er be sure that an ()\iile wliich a])pears in sucli i)osition is really
the uppermost or lowermost of its series. \'(ry often others which
would have been in reality the basal or apical lia\e become aborted,
as in the last case illustrated.
A merely recurved ovule is not to be mistaken for an anatropous
ovule. The latter, as will now be explained, has the contiguous portion
of the funicle adherent as a raphe, which comes away with the seed
at maturit\'.
Fig. 233. Erect ovule of Symmeria. 234. Horizontal ovule of Paullinia. 235. Pendulous ovule of
Guaiacum. 236. Resupinate ovule of Euonymus. 237. Suspended ovule of Drymicarpus. 238. As-
cending ovule of Euonymus. 239. Pendulous ovules. 240. Recurved pendulous ovule of Drunnichia.
Structure and Parts of the Ovule.— The recognized varieties of ovules
are based upon cxtenial structure, which will here be briefly considered.
The details of their inner structure will be considered in our cliajjter on
Fertilization.
Body and /'/////Vv////.v.- The ovule consists of a Body (Fig. iMO, a)
and a Funiculus or Stem (h). Named in the order of time in which they
are develoi)ed, the i)arts of the body are as follows:
Xucelln.s and Coals. — The Nucelius, or central i)ortion (Figs. 241 to
244, /(), containing the parts essential to reproduction, and two coats,
the Primine or inner (/,•) and Secundine or outer (.v). Certain i)arts of
these, or jjoints upon them, also have distinctive names.
The Mirropiile. — The more or less circular opening (///) left at the
apex by the failure of the coats to comi)lctcIy inclose the nucclhis is
the I'^oraincii.
80
THE GYNAECIUM
The Chalaza. — The structurally opposite end of the body, or the
point where nucellus, coats, and apex of funiculus separate from one
another (c), is the Chalaza.
The Raphe. — If the body become inverted upon its funiculus,
either partly (Fig. 24.':)) or wholly (Fig. 242), the portion of the funiculus
against which it lies (r) will become adnate to it, and is known as the
Raphe. The portion of the funiculus remaining free (/) is then specific-
ally known as the funiculus. When hereafter in this work the last
term is used it will be understood as applying to this free portion. It
is thus seen that the raphe is limited at its distal end by the chalaza;
but separation of this seed at maturity cannot take place at this point,
owing to the adnation of the raphe, as it would do if no such adnation
existed.
Fig. 241. Atropous or orthotropous ovule; /, funiculus; c, chalaza; n, nucellus; k, primine; s,
secundine; m, micropyle; em, embryo-sac. 242. Anatropous ovule; h, hilum; r, raphe; other let-
tering the same. 243. Amphitropous ovule. 244. Campylotropous ovule.
The Hilum. — Separation in such case must take place at the point
where raphe and funiculus join; hence the Hilum, as such point of
separation is called, may be variously situated, and need not coincide
with the chalaza. In Fig. 241 it is at the chalaza, in Fig. 242 at the
opposite end Qi), while in Fig. 243 (li) it is about half-way between.
The parts here enumerated are not always conspicuous and may be
easily overlooked by the beginner:
Forms of Ovules. — The nucellus is the essential part of the ovule, which
in some cases consists of nothing else, and e\e\\ this may be reduced to
its lowest es.sential elements. An ovule without either coat is Naked
or Achlamydeous; with only primine it is Monochlamydeous, and with
both it is Dichlamydeous. An ovule without funiculus, and the same
is true of any organ not borne upon a stem, is Sessile. The form of the
funiculus, as well as its direction, always calls for inspection. It may
be very short and broad (Fig. 241), or elongated and slender (Fig. 240),
and the latter form may be either straight or variously curved.
FORMS OF OVULES 81
The Anatropous Ociilc. — An anatropous ovule (Fig. 242) is one tlie
body of which is completely inverted. The raphe runs its entire length
and the micropyle is brought close to the hiluni, while the chalaza is
at the opposite end.
TJw Amphitropous Oeule. — An amphitro])ous ()vule (Fig. 243) is one
which is i)artly inverted, occupying a position more or less at right
angles with its funiculus. Its raphe runs only part of its length, and the
hilum is at some point intermediate between the chalaza and micro-
pyle, which are at opposite ends.
The CampyJotropom Omde. — A campylotropous ovule (Fig, 244)
is one which need not be at all inverted, but the body of which is
doubled over so as to bring the micropyle down near the chalaza. It
has, of course, no raphe, and the hilum and chalaza are one. It is very
difficult to distinguish this form from an anatropous ovule with a very
broad raphe.
The Atropous or Orthotropoiis Omde. — This (Fig. 241) is an ovule
which is neither doubled nor turned, the body being straight and erect
upon the funiculus, and having no raphe, the hilum and chalaza at
one, and the micropyle at the opposite end.
Before proceeding to the subject of pollination and fertilization and
the changes in the several parts of the flower consequent thereon, we
must consider in detail the torus and its modifications.
CHAPTER VII
THE TORUS
Review. — The fundamental principles of anthology are based upon
the nature of the torus as a modified branch. We have already con-
sidered the evidences of this fact depending upon its position and the
relative positions of the parts developing upon it. We shall now con-
sider some which depend upon its modifications. These are in part
permanent and typical and in part exceptional and abnormal.
Elongation of the Intemodes. — Among the latter we note that in those
frequent cases in which the parts of flowers revert to the leaf condition,
the torus often elongates, separating the floral series exactly as whorls
or spirals of leaves are separated by the internodes upon a branch. At
other times, the torus will be continued beyond the apex or center of
the flower in the form of a leafy branch. Occasionally one of the sepals
will be found at its proper radial point, but vertically distant from the
rest of the calyx, a portion of the flower stem intervening.
The Anthophore. — A similar condition, but affecting an entire series,
normally characterizes certain species, or groups of species. The
elongation may affect any internode or internodes. When (Fig. 246, a)
it is between calyx and corolla it is called an Anthophore. Sometimes,
as in Viscaria (Fig. 248), the anthophore may be very slight, so as to
escape detection until a longitudinal section reveals its presence.
The Gonophore. — A similar elongated portion between corolla and
androecium is a Gonophore (Fig. 249, a).
The Gynophore. — One between androecium and gynoecium (Fig. 249,
b, and Fig. 252, a) is a Gynophore. A thecaphore (Fig. 9) often resembles
a gynophore and may be mistaken for it. The point of articulation and
separation at maturity will determine whether the stalk is a portion of
the ovary (thecaphore) or of the torus (gynophore) .
The Carpophore.— A slender extension of the torus upward among the
carpels, which are attached to it, constitutes the Carpophore, as in
Erodium (Fig. 245). The presence of a carpophore is characteristic of
plants in the Umbelliferae (P'ig. 247).
The Gynobase. — In the Boraginaceae the carpophore is frequently
reduced to a pyramidal or conical form, or is shortened or laterally
/''O/i'il/.S OF THE DISK
83
expanded until il is iiicrcly convex or even ])l;me. To all such modi-
fications the term (lyiiohasc is ajjplicd. Jn this con(htion it may
become liollowed ont at the insertion of the carpels, as in borage (Fig.
250). In all forms of the gynol)ase it is important to note the point
of attachment of the divisions of the ovary and the scars wliich the
latter lea\e upon removal.
Fig. 245. Pistils of Erorliiim siiriiifziiiK away from the carpopliore (a). 24(5. l-'lower of Lychnis,
showing anthophore at a. 247. Carpels of parsnip attached at summit of carpophore. 248. Flower of
Viscaria with obscure anthophore. 249. Flower of Maerna, a gonophore at a, a gynophorc at h.
250. Gynobase of Borago. 251. Numerous pistils of Magnolia, imbricated upon a carpophore. 252.
Greatly enlarged gynophore of Xelumbium. 253. Ring-shaped disk (a) of Halpichroa adnate to calyx.
254. Epigynous disk (a) of Coussarea.
Abbreviation of the Internodes. — The al)o\e considerations refer to
elongations of internodes of the torus. The condition of adnation of
floral parts may, upon the other hand, be usually looked upon as one
in which the normally very short internodes of the torus are still further
shortened, so as to bring the parts into most intimate connection.
Lateral Expansion of the Internodes.- lii>tca(l of nudcrgoing a uumt
elongation of its internodes, the torus may l)c latcrall>- exi)anded at any
or all points, with or without elongation, and in imuiincrable forms.
The Disk. — An exi)ansion or appendage of this kind, although the
term may be properly regarded as including all forms of enlargement
or extension of the torus, is called a Disk.
Forms of the Disk. — The sim])lest form is, ])crliaps, that seen in the
blackberry, a hemisphere, with the j)istils arranged ui)on its surface
84
THE TORUS
(Fig. 305), although most of the enlargement here seen, as in the next,
is the accrescence of fructification. The disk of the strawberry (Fig.
304) is similar, but its pistils are partly immersed. In the rose, a
related plant (Figs. 59 and GO), the form is modified by the elevation of
the margins, instead of the center, so that a cup-shaped disk is formed,
the pistils attached over its inner surface. In the cherry (Fig. 58) the
disk is thin and lines the calyx-tube, the pistil being free. In the apple
there is a similar disk lining the calyx-tube, and it, at maturity, is
thick, fleshy, and edible, and encloses the five pistils. In the Magnolia
(Fig. 251) the torus is vertically much elongated and at the same time
Fig. 260. Saucer-shaped disk of Pseudima. 261. Similar disk of Allophyhts, but irregular and uni-
lateral. 262. Disk with two lobes coherent. 263. Cupulate, sinuate-margined disk of Hippocratea.
264. Disk of Xanthoceras, of five distinct horns. 265. Cupulate disk with lobed margin. 266.
Campanulate disk of Santalum, adnata to calyx-tube.
much thickened, the pistils adnate along its surface. In the Nelumbo,
the torus (Fig. 252) is enlarged into a top-shaped or Turbinate body,
with the pistils embedded in the flat upper surface. Instead of thus
occupying a hj-pogynous position, the disk may be projected between
any two of the circles, and it may be wholly or partly adnate to either
(Fig. 266, a), or to both of them, or it may be entirely free. When
adnate to both circles it is plain that it becomes responsible for the
existing adnation between the latter. It may then exist only at the
base, or it may entirely fill up the interspace between the parts and even
become epigynous, so that the ovary is immersed in it or buried under-
neath it (Fig. 254, a) . The adnate disk may be shorter or longer than
FORMS OF THE DISK 85
the circle to wliidi it is adnate. The simplest manifestation of tlie disk
is that of a mere swelling or ring (Fig. 200) at the summit of the torus;
its greatest that in which it becomes an elongated cu]) or tube. Either
form may be entire or more or less divided, from that Avith a mere sinu-
ately lobed margin (Fig. 263) through the toothed and lobed (Fig. 2G5)
to that consisting of entirely separate divisions (Fig. 204). It may be
regular, as in the above illustrations, or very irregular (Fig. 2()1), and
cohesion may exist between some of its divisions while the others are
distinct (Fig. 262). The lower portion may be adherent while the
upper, lobed or entire, is free (Fig. 260). It may be itself appendaged,
and it may or may not be glandular in nature. Finally, we note that
the disk may be double, its two circles occupying different internodes
of the torus. The texture of the disk is commonly thicker than that
of the other parts, but it may be laminar. It is, therefore, sometimes
easy to mistake a disk for a corolla, aborted stamen-circle, or crown.
In all its peculiarities above described, and in the number, size, and form
of its divisions and appendages, the disk is characteristic and of the
greatest value in classification, either generic, as in the Gesneriaceae, or
specific, as in Eschscholtzia.
CHAPTEPv VIII
DISSECTION AND ANALYSIS OF THE FLOWER
Apparatus Required; Microscopes. — For the thorough and convenient
examination of floral structure, it is desirable to employ both the
compound and the simple microscope, and it is better to use two forms
of the latter. The compound microscope for ordinary use should have
a focus of about li inches, and it should be provided with a strong
illumination for viewing opaque objects. The simple microscopes used
should be a dissecting microscope, having a magnifying power of
some 20 to 30 diameters and an ordinary jeweller's loup. It must not
be assumed, however, that all of these instruments, useful as they are,
are essential to the work. Excellent work in all directions can be
performed by the use of a strong loup alone, especially if it be held in
the eye or attached by means of a flat steel wire passing around the
head or inserted into a spectacle frame, so that both hands may be
free for the work of dissection.
Other Apparatus. — ^The other apparatus required is a pair of pointed
forceps, a pair of stout needles inserted into thick wooden handles, and
a dissecting knife.
Regular Order of Procedure. — ^It is well for the student in the examina-
tion of flowers to accustom himself to a definite order of procedure, as
the numerous points to be noted are thus far less likely to be forgotten
or overlooked than when considered in a disorderly manner. It is
furthermore highly desirable that the characters observed should be
written down in systematic sequence before the book is referred to.
The order of procedure is from without inward, or in other words, from
below upward. The anthotaxy should first be carefully examined and
the position of the flower with reference to others in the cluster noted,
as well as its position upon the stem and the direction in which it faces.
The position when in l)ud should be compared with that when in flower.
When flowers are aggregated in ,close clusters surrounded by involucres,
all the characters of the latter as a whole and of the bracts of which
they are composed, must be noted precisely the same as though we were
studying the calyx of a single flower. The receptacle upon which the
flowers are borne within the involucre must also be thoroughly examined
as to its size, form, and surface and the ])resence of bracts or scales
interposed among the flowers.
liFJUl.Mi OUDKU OF /'!,•( K •!■: I )Uh-J'J 87
("oiniii.u' next to the study of ;i single flower, it iiiii.st first he cxaiuiiicd
in the hud coiuhtioii and its ])r;K'floration dctcnniiuvh In inakini,'
this ohservation, it is necessary that the ])arts, first of the calyx and
afterward of the corolla, should one \)y one he carefully separated with
needle or forcei)s, heginninfj; at the apex and drawing backward and
downward, the lines of separation being closely scrutinized while the
separation is taking place. The fully expanded flower is next examined.
The presence of both calyx and corolla, or of one or neither, is first in
order, 'i'lie regularity or irregularity of the several circles can be
determined at a glance, as well as their numerical symmetry. The
same ra])id glance will determine the relative sizes of the different
circles, the exsertion or inclusion of the essential organs, the general
form of the flower, and color, surface, and positions of the parts. All
the above observations may be regarded as superficial. It then becomes
necessary to examine into those details which require dissection.
The sepals should first be turned back and examined as to their
cohesion at the base, when this is so slight as to be inappreciable upon
superficial examination. At the same time their adhesion to the inner
series, especially to the ovary, can usually be determined. The corolla
should then be carefully pulled oft' to ascertain whether any degree of
cohesion exists among its petals and also to determine the relation of the
stamensto it. Thestamens are next to be removed, and this is preferably-
done by pushing against them at the base from a lateral direction with
a blunt instrument, so as to ascertain whether they exhibit a tendency
to cohere in groups. The superficial characters of the g>'naecium also
can now be readily ascertained. The presence of a disk interposed
between gynaecium and calyx must then be searched for and its char-
acters determined, as in the case of the other circles. It has already
been explained that the disk may be easily overlooked through its
adhesion to calyx or corolla or both. Occasionally it will be overlooked
because it exists in the form of a granular or powdery mass.
The general observations thus determined should next be verified
and more accurately made by making a vertical incision through one
side of the calyx and disk, if the latter be i)resent, and carefully remov-
ing them. The body thus renio\-e(l may then be flattened out and the
relations of all its parts be fully seen. If, after the initial incision has
been made, it be ascertained that adhesion exists l)etween the calyx
and gynaecium, so that the former is not readily removed, the incision
nmst then be carried entirely through the flower and the latter sei)a rated
into two a|)proximately e(|ual portions. In either case search for
nectaries or other ai)penilages nnist next \)v made. This subject has
88 DISSECTION AND ANALYSIS OF THE FLOWER
been so thoroughly considered, that it need not be again taken up except
to say that glands, which are frequently metamorphosed stamens or
appendages to the several parts, must not be mistaken for a disk. With
the flower in this position it may also easily be seen whether the parts
are cyclical, and if so the number of circles may be determined. If
duplication has occurred, its origin in chorisis or metamorphosis is
readily determined, while if sujipression has occurred it can readily
be referred to the respective circle.
The relation of the parts to one another having been thus determined,
each of them must next be studied individually. The shape and texture,
and the division into parts, with the details of any existing appendages,
will be sought separately in sepal, petal, and stamen and in filament
and anther separately. In the examination of the stamen, it is essen-
tial that it be examined separately in direct lateral, ventral, and dorsal
views, as only thus can the true relations of its parts become known.
The form of attachment of anther to filament and the point of junction
between filament and connective are next in order, as well as the form
of dehiscence of the thecae and especially the position and direction
assumed by the sutures, pores, or valves of the latter. The chief diffi-
culty in the examination of the stamens will be in determining the part
upon which any existing appendages originate. The position which
such an appendage occupies is frequently quite misleading as to the
nature of its origin, and it must be carefully moved about with the
points of the needles, great care being taken that no delicate attachment
is severed, before it can be definitely ascertained whether an appendage
originates from filament, connective, or theca.
It is, moreover, not rarely the case that the characters of appendage
and anther are so concealed or even substituted that the one may be
mistaken for the other. The examination of the stamen is not com-
plete until the characters of the pollen, as to its being granular or
collected into pollinia, the nature and characters of the latter, and even
the characteristics of the individual pollen-grain, have been determined
by the aid, chiefly, of the compound microscope.
The gynaecium, still in position upon the torus, must next be studied
as to its relations to the latter and its composition of united carpels
or separate pistils. If of separate pistils, they must be separately
removed from the torus, great care being taken not to mutilate the
latter, and their number and regularity must be determined. If
regular, the detailed examination of one of them is sufficient, but if
irregular, one of each form must be separately studied.
The external characters of the pistil present no difficulty for exami-
PREPARATION OF DRIED SPECIMENS FOR EXAMINATION 89
nation, bnt the examination of their strueture and contents constitutes
perhaps the most (hfHeult i)art of floral dissection. It is very desirable
that the stigmas be subjected to examination with the compound
microscope, as the character of its surface and the form and distril)ution
of the stigmatic surface proper upon the style and u]nm the body,
which may at first sight be regarded as the stigma, is frequently a matter
of the utmost importance. The dissecting knife must now be used for
dividing the ovary into a number of transverse sections, which must
then be separately viewed by transmitted light. This examination will
determine the number of cells and their completion by the continuation
of the septa from top to bottom. It will also in most cases be sufficient
to enable us to determine the number of ovules and the position and
character of the placentae. All these points should, however, be veri-
fied by the subsequent examination of vertical or longitudinal sections.
Finally the ovules must be removed and their form and structure
determined by the aid of a compound microscope.
It may be pointed out in conclusion that the examination of a single
flower is not always sufficient to determine the structural characters.
Dimorphism or dichogamy, unrecognized by the student, may lead to
the most false conclusions.
The student should also be cautioned against the temptation to
examine the partially or wholly matured fruit with the idea that he
can thus more easily determine the characters of the gynaecium. As
will be shown later, great changes frequently occur in the structure
of the pistil during fructification.
Preparation of Dried Specimens for Examination.— The oi-dcr of exam-
ination is the same whether a fresh or a dried flower be under considera-
tion. In the case of the latter, however, it is necessary that it be first
thoroughly softened by immersion in water. For this purj)ose it may
be left in warm water all night or for a longer period, or as is usually
more convenient, it may be boiled for from one to five minutes, accord-
ing to its texture, in a s])oon or porcelain dish held in the flame of an
alcohol lamj). Considerable exi)erience is required to know just how
long to subject it to the action of the hot water. If too quickly removed,
the tissues will be found stifi" and resistant, while if it be boiled too
long, they will become so thoronulily linij) as to lose all trace of their
natural i)()siti<)n. If the jmxcss i> jx rfcctl^- ])(M-formed, the flower may
be thrown \i\)(n\ a blotter and after the excess of moisture has been thus
removed, will be found very much in the original growing condition
and yielding easily to manipulation.
CHAPTER IX
POLLINATION AND FERTILIZATION
Review. — It has been stated that the essential female element of
reproduction in the flower is produced in the nucellus of the ovule, the
male by the germination of the pollen-grain. It has also been shown
that these two elements are produced separately, and in most cases
remotely, from one another, and that some means must exist for bring-
ing them together in order that fertilization may be effected.
POLLINATION
In those plants (Gymnosperms, P^igs. 174 and 175) in which no
stigma exists, this is accomplished by immediate contact of the pollen
with the ovule, which is exposed for the purpose. In those in which a
stigma exists, it is accomplished by the deposit and fixation of the
pollen thereupon. To either of these processes the term Pollination
is applied.
Close-pollination and Cross-pollination. — The two elements may
proceed from the same flower, in which case the term Self-pollination or
Close-pollination is applied, or they may proceed from different flowers,
in which case the term Cross-pollination is applied. It will be noted
further that there are degrees of crossrpollination, according to whether
the elements proceed from flowers upon the same or upon different
plants. When the flowers are perfect, it is at least possible in most
cases for them to be either close- or cross-pollinated.
Cross-pollination Beneficial. — In nearly all cases, the reproductive
function is strengthened through cross-pollination, which explains
the fact that nearly all flowers are constructed so as to facilitate the
process, while most of them are so constructed as to incommode, and
very many to prevent, close-pollination. In a few cases the flower is
constructed so as to prevent cross-pollination.
Methods of Securing Cross-pollination.- I'lie methods of effecting
cross-pollination may be divided into the ordinary and the exceptional.
l'h'()\ISI(>.\S FOR ATTUACTIXa IXSECTS
!)1
The latter must he considered iii(hvi(hiall\ . The former are two —
namely, throufijh the agency of tlie wind and throufj;h that of insects
(or occasionally other animals).
Anemophilous and Entomophilous Flowers. — Flowers adapted to the
former methods are called Anemophilous; those adapted to the latter
are called Entomo])hilous. Occasionally the flower is so formed that
the movement of the water during rains, or in streams, effects pollina-
tion.
Provisions in Anemophilous Flowers. — The activity of the wind hcing
heyond the control of the flower, the adai)tati()n of the structure of an
anemophilous flower is limited to securing the benefits of such action
when it comes into play. This consists chiefly in (1) a gregarious habit
— the growing together in great numbers of individuals of one kind, as in
the case of grasses and of most of the forest trees of temperate latitudes;
(2) a very abundant j)()llcn ('.]), which is loosely fixed, one method
being illustrated by Fig. 2()7, light and easily
removed and transported; and (4) the dispo-
sition of the ovule of gymnos])erms, and the
form and disposition of the stigma and con-
nected parts of angiosperms, so as to catch
the pollen. All these provisions may be
readily seen to affect the process in the case
of Pitiiift pal list r is, for example. In this
l)laiit the ])()llcn-grains contain several cells,
all but one of them empty, thus decreasing
tlicir specific gravity. They are produced in such great abun-
dance that the crop, carried by strong winds, has been known to
fall at a great distance as a thick deposit, the so-called "sulphur-
showers" of history. The trees are densely massed, to the exclusion
of almost all others, and bear innumerable cones (Fig. .SfiO), each
consisting of numerous scales, outwardly flaring, and so (lisi)ose<l as
to catch many of the j)ollen grains and guide them downward to the
little pockets at their bases.
Provisions in Entomophilous Flowers. In entonioi)hilous (lowers, such
provisions as aboNc described for the utilization of the i)()llen-carr\ing
forces, nuist be preceded by others of a dilVereiit nature, eal(ulate(j to
first set in motion and attract these forces.
Provisions for Attracting Insects. l*i-()\isi(»Ms for atti-acting external
agents are found chiefly in the form, coloration, and size of the Hower
or of one or more of its i)arts, the ])roduction of fragrant and nutritive
Fig. 2()7
Anemophilous flower of
a grass.
92
POLLINATION AND FERTILIZATION
secretions and the exercise of these influences at the most opportune
times.
Form. — The form of the flower is efficient when it resembles a form
attractive to an insect the visit of which is desirable, or when it is
one well calculated to display effectively the coloration; and it is not
impossible that certain forms, like certain colors, are attractive jmv se.
The forms of nectar-bearing flowers are, moreover, in most cases, such
as to facilitate the collection of the food by the visiting insect, or,
when otherwise, to eft'ect special objects to be considered farther on.
For example, it is usually a peripheral or central position of the nectaries
which respectively determine the ex-
trorse or introrse dehiscence of the
anthers.
Color. — Coloration also may be
attractive, through its simulation of
an insect or merely by its serving
to make known to the insect the
presence or position of the flower
concerned — as a white, light-colored,
or lustrous flower, in attracting in-
sects which fly only when there is
little light.
Function of Neutral Floivers.—
Flowers are frequently modified in
size so as to effect these results, and
this modification is often secured at the expense of their own sexual
functions. Fig. 268 illustrates a cluster of Viburmnn flowers, the
marginal being large and light-colored and admirably adapted to
attract insects, but destitute of perfect reproductive parts. This
tendency to produce upon the same plant flowers of two kinds, the
one for display, the other for rei)roduction, is widely manifested. In
the Einphegus, the flowers produced respectively upon the lower and
upper portions of the stem exhibit this difference. In such heads of
flowers as the Daisy, the showy marginal flowers are very frequently
sterile, even though pistillate, and attract insects which then poIHnate
the inconspicuous central flowers.
Odor. — The odors of flowers, while frequently offensive to the human
sense, are supposed to be attractive in most cases to the insects whose
visits favor their pollination. They result from the evaporation of
volatile oils. The glands by which these oils are excreted and in which
Fig. 208. Inflorescence of Viburnum with
neutral marginal flowers.
POLLINATION BY BIRDS 93
they are stored may be distributed through the tissues of all or certain
of the floral parts, or their presence may be restricted to the special
appendages described below.
Nectar and Nectaries. — The nutritive substances other than pollen
to be consumed by tlio visiting insect, known as Nectars, are produced
by certain special glands and are stored in or upon contiguous receptacles
called Nectaries. The presence of these nectaries is commonly responsi-
ble for the outgrowth of the appendages to which they are often attached
(Figs. G3 and 05). At other times a part of the flower not conspicuously
modified produces and holds the nectar.
Time of Activity. — The influences here described are in almost all
cases exerted at certain times which are especially favorable for securing
the desired results. In speaking of the perigone, it has been shown
that the duration of flowers varies greatly. It may be further stated
that those which perish quickly mature and ex])and at the particular
time of day when pollination is most likely to occur. Those which last
for several days enjoy a daily resting period and another period of
greatest activity, the details of which vary in different species or classes.
Commonly, the perigone becomes more or less folded or closed during
this resting period, its form and coloration less conspicuous, the exhala-
tion of odors entirely suspended or greatly restricted, and access to the
nectar prevented altogether. At the same time that its functions are
thus inactive, its position is such as to afford it protection of various
kinds from dangers which are especially imminent during the hours in
which it rests.
Sleep of the Flower. — This condition of inactivity or rest is commonly
spoken of as the sleep of the flower. It occurs at such a period of the
day as finds the agencies specially adapted to pollination in its case
themselves enjoying their rest. As these again become active, the
flower "awakens" and all the conditions above noted are reversed, or
at least such of them as affect the flower in question. #
Diurnal and Nocturnal Flowers. — Flowers in which this active period
occurs during the day, whether they endure for but one day or longer,
are called Diurnal; those in which it occurs at night are called Nocturnal.
Besides the regular daily resting period, a great many flowers, by virtue
of special sensitiveness, possess the power of assuming such a condition
on special occasions when the conditions call for it.
Pollination by Birds. — Humming-birds, as well as insects, are active
participators in the operations above recorded. Their operations
in promoting cross-pollination in the Cinchona group have been largely
94 POLLINATION AND FERTILIZATION
responsible for some of the most far-reaching economic conditions and
results in the history of the drug trade. In exceptional instances, still
other animals take ])art in this work.
Participation by other Parts than the Flower.^ — It may be remarked in
passing that these characters, like some of those which follow, are not
restricted to the flower itself. Very frequently other portions of the
plant adjacent to the flower will be expanded, brightly colored, and
developed into special forms, while the odor of some flowers, due to
the presence of glandular tissues, is shared by the foliage and other
herbaceous portions, as in the lavender. Well-formed, large glands are
present in the axils of the primary veins of the leaves of some species
of Cinchona, although the precise function which they perform is by
no means clearly established.
Provisions for Utilizing Insect-visits. — The special contri^'ances for
utilizing insect-visits in eft'ecting pollination are far more elaborate
and varied than those for inducing them, which we have already
considered, and our consideration of them cannot be extended beyond
what is necessary to indicate their general nature and classification,
and to serve as a key in understanding the complicated modifications
which we have observed the typical flower to undergo. Usually the
effects extend in two directions — (a) toward excluding the pollen from
access to the stigma of its own flower, and (6) toward securing its
access to that of another.
Dichogamy. — One of the most frequent methods of securing the
former result is the maturing of the androecium and gynaecium at
different times. This method is called Dichogamy.
Proterogyny and Proterandry.^ — By it the ovules of a flower are already
fertilized before the mature pollen of that flower escapes from its thecae
(Proterogyny), or else the pollen is matured and utilized before the
stigmas of that flower are prepared for its reception (Proterandry).
Proterandry is well illustrated by Figs. 269 and 270. The former
illustrates the anthers erect with their pollen ready for removal, while
the stigmas are yet immature. The visit of an insect to such a flower
cannot aft'ect the stigma, but will result in the transportation of the
pollen to another flower, perhaps in the condition represented by Fig.
270. Here it will be received upon an active stigma, the anthers having
already perished and dropped beneath the margin of the corolla.
Figs. 271 and 272 illustrate proterandry assisted by a special mechan-
ical device. The former represents a flower with closely syngenesious
and introrselv dehiscent anthers.
PROrEIiOaYNY AND PROTERAXDRY
95
Its style is two-cleft, the stigmas existing iipou the inner faces of the
branches, their outer faces being clothed with stifi" hairs pointing
nj)w;ir(l. It is obvious that until these style-branches separate, polli-
nation cannot take place. Before such separation occurs, the tip of the
style is, by elongation, slowly forced u]) through the tube of the anthers.
The anthers, with their contained pollen, are mature, and the pollen is,
by the stifi' hairs upon the backs of the style-branches, torn out from
its receptacles and exposed to such agencies of trans])()rtation as may
be prepared to act upon it. Cases are even known in which the tearing
out of the ])()l]cn in tliis way is cllVctcd by a spasmodic shortening
Fig. 200. nichogamous flower of Milchrlla in first stage. 270. The same, in second stage. 271.
Dicliogamous flower of Vernoriia in first stage. 272. Style of same in second stage.
of the stamens ni)on the instant of contact by a visiting insect, the
pollen being by the same process at once discharged iii)on tiie Ixidy of the
latter. After the removal of the j)ollcn, or after the (k-ath of such
grains as fail to be removed, the style-l)ranches .separate (Fig. '272) in
readiness to receive the pollen brought from .some other flower. This
method, or some modification of it. is very common among the Co7u-
positae, and illu.strates how the study of pollination serves to explain
many modifications of flower-structure otherwi.se inex])lieable, and why
the possession of tlic latter is reganh'd by the biologist as indicating a
higher stage of de\clo])ineiit.
Dichogamy is very conmion among perfect aiieni()i)liil()us flowers,
96 POLLINATION AND FERTILIZATION
where self-pollination would otherwise commonly result, and it may
be assumed to have been the first step toward the uni-sexual state, so
common among flowers of that class. Careful notice should be taken
of the fact that in dichogamy the retarded state observed in androecium
or gynaecium is but temporary, and that the finally develc^ed form is
the same, whether the flower be proterandrous or proterogynous.
Dimorphism. — A far more profound modification is that in which there
is a permanent change in the androecium (Fig. 273) of one flower and
a similar change in the gynaecium (Fig. 274) of another, by which a
similar result is obtained to that proceeding from dichogamy. Such
a provision constitutes Dimorphism. By a modification of it, a third
form of flower, intermediate between the other two, is produced, con-
stituting Trimorphism. The explanation of the case of dimorphism
here exhibited is as follows : An insect visiting flower No. 1 and thrusting
his proboscis deeply into the corolla-
tube in search of nectar, brings his
body into contact with the stamens,
and pollen is deposited upon it. The
next flower visited may be one like
2/^4^ No. 2, having a long style. The por-
tion of the body which is now covered
with pollen will then be brought into
Fig. 273. Long-styled form of dimorphous COUtact with the StigUia, UpOH wllich
aoy^er of Houstonia. 274. The same, long- ^j^^ jj^^^ j^ dcpOsitcd. At the SamC
staminate form. ^
time a different part of the body is
being laden with pollen from the short stamens of flower No. 2, to be
deposited upon the short pistil of still another flower, similar to No. 1.
If perchance two flowers of the same form are visited in succession, the
result is that an additional deposit of pollen is secured, or at most a
portion of the pollen already being carried is left upon the stamens of
the visited flower.
As will be seen by a consideration of typical examples of each, dimor-
phism is more intimately connected with the transferring of the pollen
than is dichogamy, though the latter is rarely without some special
provision for thus supplementing the effect which it produces in
excluding the pollen from the stigma of its own flower.
In conclusion, it may be said that even if, by some failure in the
provision here described, the flower should become self-pollinated, we
have excellent reasons for believing that pollen from a different flower
which might be deposited at the same time would find an advantage
CLEISTOGAMY 97
accorded to it by whicli it would he enabled to first reach and fertilize
the ovules.
Coercion of Insect by Special Forms. — The assuming of a form con-
venient for the visiting insect, to which reference has been made, is
very frequently interfered Math for the purpose ' of forcing the insect
into such a position as shall favor or compel the removal of the pollen,
a labor which is by no means agreeable to it and which it not rarely
seeks to avoid, as in the case of the bee, which cuts a hole at the base
of some corollas, through which its food may be extracted.
No better illustration of such coercion of the insect by special form
could be selected than that of the Asclepias (Fig. 27G). The nectary is
at a, in the bottom of a large slipper-shaped pouch. Into this pouch
the insect would naturally thrust its proboscis in the direction of the
276.
Fig. 275. Highly magnified papillose stigmatic surface. 276. Vertical section of flower of Asclepias:
a, nectary; b, blind pouch; c, horn; d, pollinium; e, glutinous corpuscle of same; /, stigma.
point b, thus avoiding contact with the pollen. The appendage c,
however, cuts off this line of approach, sei)arating the blind pocket b
from the nectary a. In order to reach the latter, the insect is now
forced to seek an entrance at the ])oint d, his head being thus forced
into contact with the pollen at e, which adheres and is carried away to
be applied to the stigma/ of the next flower visited.
In spite of the possibility of thus effecting a rough classification of
some of the methods of securing cross-pollination, it is yet true that the
great majority of instances are not subject to classification and must be
denominated special, or else that they combine some si)e(ial arrange-
ments with such general methods as have been described.
Cleistogamy. — Flowers which are self-fertilized before exi)ansion are
Clei.stogamous. Occasionally, fertilization takes i)laee without the
removal of the pollen from the anther.
7
98 POLLINATION AND FERTILIZATION
Fixation of the Pollen. — The pollen thus transferred to the stigma
must be fixed there in order that fertilization may follow pollination.
This process is effected by contrivances little less elaborate, although
more minute, than those which have been described. These con-
trivances relate in part to peculiarities of the pollen. As regards the
stigma, fixation is effected most generally by means of the viscid
secretion to which reference has been made, the stigma being essentially
glandular in nature. Appendages in the form of hairs, scales, or
papillae (Fig. 275) are very common. In some cases the divisions of
the stigma are sensitive and close elastically upon the pollen as soon
as it is deposited. With the fixation of the pollen upon the stigma,
pollination is completed and preparations for fertilization begin.
FERTILIZATION
A knowledge of fertilization is of importance to the pharmacognosist
only as it throws light upon the characters of the fruit, in which we
include the seed as a part. Only the principal facts connected with the
subject will, therefore, be here considered.
Internal Structure of the Ovule. — The gross appearance and parts of
the ovule have already been described. Its internal structure is illus-
trated in Fig. 277.
The immediate function of the flower has been seen to be the pro-
duction of spores. These spores are to act as reproductive bodies, which,
like seeds, they can do only by germinating and growing in a suitable
soil. This function of each will now be considered.
We have seen that the macrosporophyll is the carpel, its macro-
sporange the ovary. The macrospore itself is the large centrally
located cell of the nucellus, which is to develop into the embryo-sac, e.
The natural soil for the germination of this spore is the tissue of the
nucellus where it is formed. Its germination takes place immediately
and results in the development of the several distinct bodies figured in
the illustration. Of these bodies, the oospore or vegetable egg, o, is
the ultimate female reproductive element.
The Gymnospermous Ovule. — The OA'ule of gymnosperms agrees in
the possession of an embryo-sac, with several bodies corresponding to
the oosphere of angiosperms, but with the other corpuscles not clearly
developed. The foramen is secretory, so as to be adapted to acting
upon the pollen-grain which it receives, as does the stigma in angio-
sperms.
77//'; roLLKX-TUBE 99
The Female Gametophyte.- As is tlic i)r<)(Iii(t of seod-germination,
so is the product of sixuv-uvnuiiiatioii a plant. The plant which results
from seed-germination, and wliicli ])r()duces spores, has been called a
si)orophyte. That which results from spore-germination, and the
ultimate function of which is the production of seed; is called a gameto-
])hyte. Hence the mass contained within the embryo-sac is such a
l)lant. the female gamctophyte. It will rest in the state in which we
now find it until its oiisphere is acted upon by the male element, which
wc ha\e yet to consider, and if such action does not occur, it will die
and (lisa])pear.
Connection between Stigma and Ovule. — Between the ovule thus
prepared and the stigma, there is an almost continuous connection
through conducting tissue, extending through the body of the stigma,
style, and placenta. The extent of this conducting tissue, like that of
the stigmatic surface, is usually greater or less according to whether
there are more or fewer ovules to be fertilized.
We have seen that the soil u]K)n which the microspore is intended to
germinate is the stigma, in angiosperms, and the foramen of the ovule
in gymnosperms. The process of germination is dependent upon the
following structural characters:
Structure of the Microspore.^ The ])()llcn-grain consists of a highly
hygroscopic mass of tissue, ])artly vital and ])artly nutritive, the latter
of variable composition, surrounded !)>■ a thin, iion-])erforated, highly
elastic membrane, the Intine, and this in turn by a thicker, non-elastic
covering, the Extine, or "Exine," bearing one or more comi)lete per-
forations, very thin ])laces, or otherwise modified ])oints u])on its surface.
In exce])tional cases there is instead but a single wall.
Germination of the Microspore. — The ])rocess of fertilization is illus-
trated l)\- Fig. 27s, and the onhiiary jjhciionicna are as follows: The
l)ollen grain (a), fixed \i\un\ the stigma of the angiosjierm, or upon the
sununit of the o\ule of the gymnos])crni, the hygroscoi)ic contents
absorb moisture from the secreting or transuding surface with which
it is in contact, the nuiss increases in si/e and distends the intine which
surrounds it. Shortly ccll-di\ision of its contents takes place, the com-
i)ined changes constituting the germination of the micros]>ore.
The Pollen-tube.— Through one or more of the ])erforations of tlu>
extine already existing, or forcii)ly made )>> this ])ro(ess, ])rotrude
prolongations of the pollen contents, still cnxcioped in a |)rocess of the
intine. Such a i)roIongation is known as a Pollen-tube {h).
100
POLLINATION AND FERTILIZATION
The Male Gametophyte. — A body of this kind, proceeding from the
germination of a matured spore, is properly to be regarded, Hke its
female homologue, as a plant body. It is to be noted, in passing, that
it can be equally well produced by germination upon other surfaces
which present the proper conditions.
Fig. 277. Diagram illustrating structure of ovule: s, synergidae; o, o6sphere; sek, nucleus; e,
embryo-sac; g, antipodal cells. 278. Diagram illustrating fertilization: a, pollen-grains on stigma;
h, pollen-tubes penetrating stigma and style and entering ovarian cavity, one of them entering the
foramen of the ovule at c.
Following the same course of reasoning as in the case of the female
gametophyte, we see that this pollen-tube is the male gametophyte.
Its structure is not, or apparently not, even so highly developed as in
the case of the other.
The Male Cell. — At its lower end are one or more little bodies which
constitute the male element and which are to fertilize the oosphere
which we have already observed within the embryo-sac. This fertil-
izing element is the INIale Cell, or Antherozoid.
In some of the lowest of the flowering plants, and in most of the
Cryptogams, this male cell is highly organized, with a specially formed
body, is capable of locomotion, and possesses peculiar powers of
nutrition. It is comparable with the spermatozoon of animals.
The Descent of the Pollen-tube. — The male cell or antherozoid is quite
as incapable of reproducing by itself as is the oosphere, and its sole
function is to act upon the latter, fecundating it. This is accomplished
THE DESCENT OF THE POLLEN-TUBE 101
by the penetration of the loose celkihir tissue oi tlie stigma, then of tlie
style, by the pollen-tube. Nourishment for its growth and movement
is afforded partly by the contents of the pollen-mass and partly by
absorption from the tissues of the stigma and style with which it is in
contact. This process is known as the Descent of the Pollen-tube, and
by it the male cell or antherozoid is brought into the ovarian cavity and
into the immediate presence of the ovule. It then finds the foramen
of the latter, contact and fusion of the male cell with the oosphere is
effected, and fertihzation is accomplished.
Among cryptogams, there are no such speciallj' adapted sites pro-
vided upon the plant-body of the parent for the germination of spores,
which reproduce upon any appropriate soil. They may be of two
sexes, the macrosjiore resulting in a gametophyte which produces
female cells, the microspore in one which produces antherozoids, or the
one gametophyte may produce both organs. In either case, the anthero-
zoids commonly tray el to reach the female cell. Fertilization occurs
very much as in phanerogarns, but no seed is produced, as will shortly
be explained, the embryo proceeding at once to grow and reproduce a
sporophyte.
CHAPTER X
CARPOLOGY: FUNCTIONS AND STRUCTURE OF THE FRUIT
FRUCTIFICATION
Fructification and its Objects, — The changes effected by fertiHzation
extend to all parts of the flower and even to other parts of the plant.
A consideration of the objects of the process will prepare us to under-
stand the nature of the changes. The objects are (1) the production
and maturing of one or more seeds, including provisions for their pro-
tection and nourishment throughout the process, together with the
nourishment of the parts w^iich thus protect them; (2) provisions for
their transfer, still enclosed in their container, to a suitable place
for germination and the fixation of the latter there, or (3) provisions for
their exit from such container and (4) their transfer after such exit to
the place of germination and their fixation there. The combined pro-
cesses connected with the attainment of these objects is Fructification,
and the product thereof is the Fruit.
Fructification Results in the Death of Some Parts, the Stimulation of
Others. — It is clear that the energies of the plant should not l)e called
for in the further development or preservation of any parts of the flower
which .are not serviceable as a part of the fruit in the attainment of
the above-named objects, unless possibly they may possess some other
function foreign thereto, as, for instance, the action of the stamens of a
flower in which fructification has already begun, in fertilizing the ovules
of some other flower. We should, therefore, look (a) for the disap-
pearance or death of all floral parts not thus serviceable, and (6) for
the stimulation and development of those which are. That the first of
these two objects is an immediate result of fertilization is strikingly
and unhappily illustrated in the behavior of ornamental flowers in which
the latter process is allowed to take place. Those who produce for
the market the handsome and expensive flowers of orchids are obliged
to carefully exclude insects from their greenhouses. Valuable flowers
which, without fertilization, would last for several weeks, wither and
die within a few days, or even hours, after such process has occurred.
That the accomi)lishment of the second-named object is no less imme-
diate is apparent upon considering the morphology of the fruit.
A^^IT" PARTS DEVELOPED BY FRUCTIFICATION 103
Parts Useless in Fructification. — The only i)()rti()n of the flower which
is certain to he in no case utihzed in fructification, and, therefore, to
disappear after fertiHzation, is the actual stigma, and the stamens when
they are non-adlicrent. The stamens, as has been shown, may be ser-
viceable for other purposes, so that their death depends rather upon
the performance of their inchxichial function than upon fertihzation.
In proterogynons flowers this function is actuall\- stinnilate(l by the
conii)k'tion of fertiH/ation in their own flower.
Parts Useful in Fructification. — Upon the other hand, we are not
certain of a requisition in every case for the preservation and develop-
ment of any part other than the particular ovules which l)ecome fer-
tilized, the ovarian walls of the i)istil or pistils containing them (and
in some cases only a part of these), and of the torus. The death or
decay, therefore, of any or all of the other parts will be determined by
the indiA-idnal or class habit of the plant concerned.
Accrescent Parts. — To any part other than the ovary, which thus
develops and enlarges as a part of the fruit, the term Accrescent is
ai)plie<l.
Accessory Fruits. — Fruits of which such accrescent i)arts form the
conspicuous ])ortion are called Accessory fruits.
New Parts Developed by Fructification. — Finally, we must note that
new ])arts, of service in the fruit, frequently develop in the course of
fructiflcation, u])on either pericarj) or seeds, just as special a])])endages
develop u))on the floral organs for performing special function in con-
nection with pollination. That such additional parts exhibit little, if
any, (le\-eloi)nient (Jui'ing the floral stage, is due to the fact that an
enormous waste of energy on the i)art of the plant would thus be
involved. Of all the flowers j)roduce(l by a plant, only a niiiioi- ])ortion
usually accom])lish fructiflcation, and of all the ovules produced by any
gynaecium only a minor j)ortion usually produce seeds. The develop-
ment of these su])erfluous flowers and o\ules constitutes in itself a
serious waste, l)ut it is a necessary or, upon the whole, an economical
one, as it tends in the end to secure the full degree of fructification by
tiie plant. The develojiment, however, upon such superfluous flowers
or ovules, of parts which will be of value only in case fructiflcation is
effected, would be anything l)ut (>cononiieal. Hence the general
rule that ])arts of the fruit which are of no use in elfiM-ting ])ollination
and fertilization are not (le\-elope(l until after these functions are
performed.
104 CARPOLOGY: FUNCTIONS AND STRUCTURE OF THE FRUIT
FRUIT
Structural and Physiological Senses of the Term, — There are two dis-
tinct senses in which the term "fruit" may be employed. In the first
instance, we may regard it as the structural product of the develop-
ment in fructification of a pistil, or in the second as an organ performing
a certain reproductive function or functions. The limitations of our
definition of the term will vary accordingly.
Entire Gynaecium as the Fruit. — In many cases the ripened gynaecium
performs or may perform the fruit-function entire, as in the cherry,
the strawberry, the blueberry, the so-called "seed" of the sunflower, or
the pod of the bean or digitalis. In such cases the solitary ripened
carpel (cherry and bean) or the aggregation of ripened carpels (as in the
other illustrations), of a gynaecium, constitutes the fruit, from either
point of view.
Either the Whole or Part of a Gynaecium as a Fruit. — In other cases the
several carpels of a gynaecium are separate from first to last as pistils,
as in the case of the buttercup. The entire collection then constitutes
a fruit, being the product of a flower, but each of the individual pistils
must also, from a physiological standpoint, be regarded as a fruit, inas-
much as it performs the fruit function independently.
Part of a Pistil as a Fruit. — Again we find, as in the case of the borage,
that carpels originally coherent, separate before performing their
function, so that we must regard each of the separated carpels, as well
as the entire gynaecium, as in the nature of a fruit.
Part of a Carpel as a Fruit. — Occasionally even a carpel will itself
divide into separate parts, each of which is equally entitled to be
designated as a fruit, as in the case of the 2 carpels of the lavender,
which separate into 4 nutlets.
Gynaecia of a Number of Flowers Forming a Fruit. — In still other cases
the ripened gynaecia of more than one flower cohere and perform the
fruit function as one body, as in the case of the partridge-berry, the
fig, and the mulberry.
Finally, we note that many fruits can perform their function in either
way — namely, by means of their carpels, or parts thereof individually,
or as aggregations proceeding from a single flower (blackberry), or
from many flowers (fig, hop, etc.). It is, therefore, to be noted that
that which is at one time to be regarded as a fruit is at another time
only a part of one, according to the manner in which it performs its
function.
THE PERICARP 105
Kinds of Fruits. — From the foregoing considerations, we may deduce
the following definitions of fruits:
A Fruit is a separate ripened carpel, or a separate part thereof, or an
aggre,c;ation of ripened carpels, together with any adherent j)arts.
Multiple or Collective Fruits are those proceeding from the gynaecia
of more than one flower.
Aggregate Fruits are those which proceed from a number of pistils
of one flower.
Simple Fruits are those proceeding from a single pistil.
Apocarpous Fruits are those consisting of one carpel or of two or
more non-coherent carpels.
Syncarpous Fruits are those consisting of coherent carpels.
Accessory Fruits are those in which some part other than the ripened
ovary constitutes a conspicuous portion.
Structural Composition of the Typical Fruit. — The student cannot have
failed to note in reading the above statements that the composition of
the fruit is extremely variable and in some cases complicated. In
accordance with this fact, the classification of the parts of fruits is
o])en to great differences, according to the principles upon which the
observer bases his classification. The typical fruit may be considered
as that which consists only of the ripened pistil with the contained seed
or seeds.
The Pericarp. — As a fruit is regarded as possessing but two portions,
namely, the seeds and the Pericarp, the pericarp of such a tyi)ical fruit
would consist of a ripened })istil exclusive of its seeds, but since, in many
cases, the calyx, disk, or other part is closely adnate to the wall of the
ovary and more or less indistinguishable from it, it becomes imprac-
ticable to restrict the term pericarp to a part consisting only of the
pistil. Again we find that there are all intermediate forms and degrees
of adnation and sei)aration between the ovary and the accrescent ])arts
of accessory fruits. It, therefore, appears most convenient to define
the pericarp in a broad sense as the fruit with the exception of the
seeds.
The Pseudocarp or Anthocarp. — AVhen the pericarj) consists chiefly
of other elements than the ovarian wall it is called a Pseudocarp or
Anthocarp.
Layers of the Pericarp. — When the pericarp is seen to consist of three
demonstrable layers, these are called respectively Fxocarp, the outer;
Endocarp, the inner; and Mesocarp, the middle. When the exocarp
is thin and membranous, like the skin of a plum, apple, or tomato,
106 CARPOLOGY: FUNCTIONS AND STRUCTURE OF THE FRUIT
it is called an Epicarp, and when an endocarp is hard and strong inside
of a fleshy layer, like the stone of a peach or the "core" of an apple, it
is called a Putamen.
Modes of Performance of the Fruit Functions. — We shall now consider
the maimer in which tlie fonr objects of fructification are accomplished
through the modifications effected in each of the floral parts and in
the parts adjacent, by fertilization, including such new appendages
as are thus caused to develop.
Growth and Maturity. — The development and maturity of the fruit
are eft'ected by the stimulation, through fertilization, of the nutritive
functions of the pistil, the torus, adjacent portions of the plant, and
through the combined influence of all the flowers, a similar stimulation
of all portions of the plant.
Protection. — So far as the development of a protecting container for
the maturing seed is concerned, the object in general demands the
development of nothing more than the ovarian wall; but the effects of
adnation and the requirements of the other objects result in the exten-
sion of this process to various other parts of the flower or even of its
supporting parts. The development of such parts in connection with
the ovarian walls will therefore receive attention in considering the
methods by which such other objects are accomplished.
The Abortion of Septa and Cells. — It has been stated that not always
are all of the ovarian walls involved in fruit development. A gynae-
cium possessing several pistils may fail to develop one or more of them
in fruit, and when these are adnate into a compound o^'ary, as in Val-
lesia, one or more of them may likewise fail to develop. A several-
celled ovary, as in Calesium (Fig. 279), may, after the fertilization of
one or more ovules in one or more cells, permit the abortion of those in
the other cells, the septa of the latter being then crowded against the
outer wall by the growing seeds, or even disappearing, so that the fruit
will contain a smaller number of cells than the ovary which produced it.
The partial obliteration of cells in a similar manner is well shown in the
fruit of Diospyros {Fig. 280).
Mr. J. H. Hart has contributed three fruits taken from one crop of
a single plant (Fig. 285, a, b, and c), the first showing the development
of all three of the ovarian cells, the others having respectively one and
two of these aborted.
The Development of New Septa and Cells. — x4dditional walls, upon the
other hand, may develop during fructification. Datura has a 2-celled
ovary (Fig. 221), but a 4-celled fruit (Fig. 223), and this occurs regularly
TRAASl'ORTATIOX OF THE FRUIT
107
in the Labidfar. Tlie newly formed walls are not always vertical. The
fruit of Arsrlii/noiiwne (Fig. 351) and that of Sophora (Fig. 352) divide
trans\(M-seiy into one-seeded joints.
Special Defensive Provisions, ("oneerning the protection of tlii' fruit
and seeds, we note that its full accomplishment often calls for other
defensive i)rovisions than those against merely mechanical forces, in
the form of appendages constituting an armor. These are sometimes
an outgrowth from the ovary itself, as in Sfnuiioniinn (Fig. 282), some-
times u])on an enclosing calyx (Fig. 283), an enclosing wall consisting
of a hollowed branch, ;is ni tlu> i)rickly pear (Fig. 281 ), or soinetiines upon
Fig. 279. Cro-ss-sfction of yoiiiiK fruit of Calcsium, the cells tlisappuiiriiis; uxicpt that in wliich an
ovule has been fertilized. 2S0. Diospyros, the same. 2S1. Fruit of Opuntia, immersed in prickly end
of branch. 282. F'ruit of Datura, with prickly ovary. 283. Of Riancjc, with prickly calyx. 284. Of
Castena, with prickly involucre. 285. Three palm-fruit.s from the same tree, with one or two, a, with
none, of the cells aborted.
an enclosing involucre, as in the chestinit burr (Fig. 284). At other
times the protection is secured by develoi)ing acrid or otherwise dis-
agreeable pericarps, as the husk of the walnut or the pulp of the colo-
cynth. These defences may be ett'ective only during the maturing stage,
as already pointed out, or their deterrent action may be permanent.
In tlie same direction are to be considered the effects of ])oi.sonous
principles proper and the inedible nature of a pericarp pending the
maturing of the seed, })ut which afterward becomes edible.
Transportation of the Fruit.- The transfer of the fruit to the jjlace of
germination is securetl by inctliods which for the ni(»t part admit of
108 CARPOLOGY: FUNCTIONS AND STRUCTURE OF THE FRUIT
classification. We shall first consider those provisions which utilize
the agency of the wind for this purpose.
Transportation by the Wind. — We note, first, that the weight of fruits
to be thus transported is reduced to a minimum. They are in almost
all cases one-seeded (Monospermous), the loss due to this character
being made good by the fructification of a large number of flowers.
The one-seeded condition of such fruits is not restricted to families
which are characterized by it. Many fruits of the Leguminosae, which
are commonly several- or many-seeded, as the pea and bean, become
one-seeded when adapted to wind-transportation (Figs. 296 and 299).
Fruits which are not one-seeded may divide into one-seeded parts,
easily separable, to facilitate transportation by wind or other agencies,
as has already been shown.
Morphology of Fruit-wings.— Such a state having been attained, the
action of the wind upon them is next secured through the development
of an expanded surface of some kind, commonly a wing or plume.
In the Platypodium (Fig. 296) it is the entire wall of the ovary, in its
original nature a pod, like that of the bean, which becomes developed
into a wing. In the elm (Fig. 287) it is likewise the ovarian wall. In
the carrot (Fig. 288) and the Rumex (Fig. 289) it is an enclosing accres-
cent calyx. In the Piptoptera (Fig. 290) it is two accrescent lobes of
such a calyx. In the Zinnia (Fig. 291) a persistent corolla performs
the same office. In the hop (Fig. 292) an accrescent bract is made to
serve the office of a sail. The fruit of the Cardiospermum (Fig. 294)
represents a class in which the thin pericarp, instead of being expanded
into a wing, is inflated into a balloon-shaped receptacle, subserving a
similar purpose. Plumes, consisting of the modified persistent calyx,
are seen in the Valerian (Fig. 293) where it is present, though concealed
by a circinate praefloration, from the flowering stage, while in the
Phyllactis it is not developed until after fructification begins. A
plumose style is seen in Pulsatilla (Fig. 286).
Transportation by Attachments. — We shall next note the cases, per-
haps even more numerous, wherein use is made of passing bodies by
providing such appendages as shall serve to attach the fruit to them.
Fig. 298 represents the fruit of a Rumex, in which the calyx is divided
into hooks for this purpose. Fig. 297 shows another species, in which
this method is combined with wind transportation, a combination which
is very common among the Umbelliferae. The accrescent calyx teeth
(awns) of Verbesina (Fig. 295) are adapted to piercing passing bodies,
while at the same time the adnate tube is winged. In Bidens (Fig. 300)
TRANSPORTATION OF THE FRUIT
109
similar awns arc ])ar}H'(l and adhere very tightly to anything which
they may pierce. In the case of the burdock (Fig. 301) it is an involucre
which bears such hooks. Similar hooks are found upon the outer
wall of the ovary itself in many cases. Sometimes the style is recurved
at the apex, thus forming a terminal hook, while at others (Fig. 302)
the apex, after performing the stigmatic function, falls away, but leaves
a hooked lower joint to become efl'ective in the fruit. The attachment
is not alw^ays thus secured by means of distinctively piercing appendages.
The surface may be rendered adhesive in other ways, as seen in the
minute structures covering the fruit of Desmodium.
Fig. 286. Fruit of Pulsatilla, with plumose style. 287. Winged epicarp of Ulmus. 288. Of carrot.
289. Winged calyx of Rumex. 290. Of Piptoplera. 291. Winged petal of Zinnia. 292. Winged
bract of hop. 293. Plumose calyx limb of Vahriaita. 294. Inflated pod of Cardiospcrmum. 295.
Winged akene of Virhesina. 290. Winged legume of Plalypodium. 297. Winged and hooked calyx
of Rumex. 298. The same, hooked only. 299. Winged legume of Plerocarpus. 300. Hooked calyx
of Bidens.
Trans porf (if ton through Edible Pericarps. — We shall next consider
another large class of fruits, which dci)end for their trans])()rtation upon
the possession of cdil)le pericarps or edible portions of them. Such
fruits may be eaten with the contained seed, as in the case of the straw-
berry or small cherries, in which case transportation is effected during
the process of digestion of the pericarj); or, as in the case of the peach
and ])lum, the fruit may be too large for such process, depending for
trans])ortation upon carriage by a ])arent to its young. In still other
cases they are of such a nature that they can be carric<l and stored for
110 CARPOLOGY: FUNCTIONS AND STRUCTURE OF THE FRUIT
winter use. The edible portion is in some cases, as in that of the banana,
highly nutritious, while in others it is apparently eaten merely for its
palatability or for its thirst-quenching properties.
Special Protection to Seeds of Edible Fruits. — Some special form of
protection is commonly required for the seeds of edible fruits. That
of the peach is enclosed in a hard stone, so that it shall not be a})raded
as the pulp is pecked or bitten away. Those of the cherry and straw-
berry are enclosed in similar hard coats, which resist the digestive process
as well. The more or less laxative or purgative properties of many
fruits doubtless contribute to such protection by the more prompt
dejection of the seeds which is brought about by their action.
J(?P.
Fig. 301. Lappa fruit with prickly involucre. 302. Fruit of Gt-um with jointed .style. 303. Fruit
of Gaulthcria, with fleshy calyx. 304. Of strawberry, with fleshy torus. 305. Of blackberry, with
fleshy torus and ovaries. 306. Of cashew, with fleshy pedicel. 307. Of tamarind, with fleshy middle
layer of pod. 308. Of apple, with fleshy calyx and disk. 309. Of papaw, with fleshy inner layer of
ovary. 310. Of belladonna, with fleshy ovary. 311. Of fig, with fleshy hollowed end of branch.
312. Of watermelon, with fleshy placentae.
Origin of Edible Portion. — The origin of the edible portion is various.
In the strawberry (Fig. 304) it is the complete torus, and this only. In
the blackberry (Fig. 305) such a torus is combined with a partially
fleshy ovarian wall upon each of the ripened pistils. In the rose (Fig.
59) it is a similar torus, but hollowed, probably with other elements
combined. In the apple (Fig. 308) it is a fleshy-thickened disk, together
with the adnate calyx lined by it. In the checkerberry (Fig. 303) it is
the calyx only which becomes fleshy. In the gooseberry it is the calyx
and the entire ovary, but without any disk, while in many other berry-
like fruits it is the ovary alone. In the plum and cherry not all of the
SPECIAL !>h'<)\/SI(>XS FOR I'RFA'KNTI N(i TUAXSl'OUTA TION 1 1 1
ovarian wall is edible, its endoearp heeomiiifjj a putaiiieii. In the lemon
(Fig. 329), the papaw (Fig. 309), and the pnnipkin it is the inner i)ortion
which is edible, while the outer is not. In the waterniclon the ])lacentae
comprise almost the whole of the e(lil)le ])ortion (Fig. '.\V1), while in the
tamarind it is the middle layer of the ovary (Fig. '.\()1).
Edible Portions Not Pertaining to the Flower. — In all of the above-
mentioned cases it is some one or more of the parts of the flower which
eventually forms the edible i)eriear]), but there are numerous cases in
which other parts of the plant contribute to or form the whole of such
l)()rti()n. In the Cashew (Fig. ;>()()) the ovary (a) enlarges but little,
while the j)edicel {b) undergoes a great enlargement and becomes
edible. In the cactus (Fig. 281) the end of the branch is hollowed out
and the wall so formed l^ecomes the edible pericarp of a single flower.
In the fig (Fig. 311) we have a similar hollowed branch, but instead of
being occui)ied by a single flower, the wall is lined by a great number of
them.
Miscellaneous Methods of Transportaiion. — Besides the more common
methods of seed distribution referable to the pericarp, which are thus
subject to classification, we find numerous special devices which cannot
here be enumerated in detail. Fruits which grow beside or in the
vicinity of streams or other bodies of water are commonly adapted in
some way for using the latter as a vehicle for transportation. They are
freqnently of a rounded form and of considerable weight, so that njion
falling they will roll into the water, where they are then enal)le(l to
float i)y virtue of low specific gravity, due often to the presence in them
of large cavities, as in the case of the cocoanut. The pericarp is in such
cases usually furnished with some means of protection against the action
of the water. The fruit of a s])ecies of Arena is so constructed that by
the change of form and position of its long awns in dry and wet weather,
respectively, it is enabled to tra\"el.
Special Provisions for Preventing Transportation.— Finally, we must
note that some fruits are ])rotected by special devices against trans-
portation. Thus, the mangrove possesses a seed which germinates while
still attached to its parent and which does not sever its connections
therewith until the young ])laiit has descended many feet and fixed
itself into the nuid below. The jx'annt, after antlu'sis, drixcs its o\ary
beneath the surface of the soil, where its fruit is dexcloped ( h'ig. .■!]:!).
Plants ])()ssessing such habits are ahva\s highly gregai'ions, ()ccu])yiiig
the ground to the exclusion of all other species, thus .securing their
perpetuation even wliile their di.ssemination is prevented. The high
112 CARPOLOGY: FUNCTIONS AND STRUCTURE OF THE FRUIT
degree of adaptation secured by the peanut is still further illustrated
by its apparent power to support itself by means of these buried
branches, should the parent stem in any way become severed; a very
important protection, in view of the highly nutritious character of the
herbage, which renders it liable to partial destruction by grazing
animals.
<3/J.
Fig. 313. Peanut plant, with buried fruits.
The Fixation of Fruits after Distribution. — The fixation of many fruits
with their contained seeds is secured by a series of devices no less
interesting than those which effect their distribution. Fruits like those
represented in Figs. 75, 76, etc., are commonly more or less sharpened
or narrowed at the lower end, which is much the heavier, so that they
shall the more readily penetrate a favorable surface. Their bodies,
moreover, are commonly toothed or hispid upward, so that the tendency
is for them to sink more and more deeply until properly interred. The
fruit of Viscum, whose seed can develop only upon the bark of trees,
DEHISCENCE 113
is intensely adhesive, so that in i'alHng it does not readily })ound away,
bnt l)eoomes adherent to the first sohd l)ody wliich it eneonnters.
Provisions for Scattering Seeds. — As a rule, fruits whieh are provided
with special dexiees for their transportation are not designed for the
discharge of the contained seed, which escapes accidentally or germin-
ates while still enclosed. Provisions for the discharge of seeds, therefore,
ordinarily apply only to such fruits as complete their function at the
place of origin. For provisions for the distribution of such plants, we
should naturally look to the seeds themselves; yet to this rule there are
mnnerous exceptions, for many fruits which never leave the place of
growth yet possess various devices for distributing their seeds over a
greater or less area by \irtue of forces inherent in their pericarps. The
common name of the Impatiens, "touch-me-not," is derived from the
habit of its fruit of exploding with much force, discharging its seeds
meantime to a considerable distance. The fruit of Iliira similarly
explodes, and with such violence as to cause a report like the discharge
of a firearm. Elaterium (Fig. 314), during the ripening process, collects
by osmosis within its cavity an amount of liquid which exerts a powerful
outward pressure upon the pericarp. When fully rijjc, the slightest
contact with another body causes the pericarp to leap away from its
attachment, with the production of a hole at its base through which
the seeds are expelled with much force.
Dehiscence. — The ordinary method of providing for seed discharge is
by means of a splitting of the pericarp known as Dehiscence.
Dehiscent and Indchiscent Fruits. — A fruit so splitting is said to
Dehisce, and is known as a Dehiscent or Dehiscing fruit. Other fruits
are called Indehiscent. True dehiscence is longitudinal, although the
term is not altogether denied to other forms, provided the line of
separation is regular and constant (Figs. 325-327).
The Valves. — The parts into which pericarps dehisce arc called
Valves. The valves may separate entirely or remain attached in
various ways.
Forms of Dehiscence. — Dehiscence may occur at the ventral or at the
dorsal suture or at both. If at the ventral, then the carpel (Fig. 349),
or each carpel if it be i)art of a ])olycarpellary ])istil (Fig. 310), will be
left entire. If the polycar])ellary ])istil have se\eral cells, xcntinl
dehiscence must involve the separation of the carjjcls by the si)litting of
their walls or septa, whereas in the one-celled form se])ta do not exist
or are incomplete. Nevertheless, the principle is identical in the two
cases, and the former mode is called Septicidal dehiscence (Fig. 316).
8
114 CARPOLOGY: FUNCTIONS AND STRUCTURE OF THE FRUIT
In such case the carpels, after separating through their septa, are not
necessarily open, and unless the dehiscence shall follow the wall into and
my
^ ti'f
J/4
SIS.
3/6.
3/7
Fig. 314. Fruit of Elateriuvi discharging its seeds and watery contents. 315. Loculicidally dehiscent
pod of 7ns. 316. Septicidally dehiscent pod of Hypericum. 317. Transverse diagram of a margini-
cidally dehiscent pod.
Fig. 318. Apical dehiscence of Cerastium. 319. The same, Eucalyptus. 320. Circumscissile dehis-
cence of Mitracarpus. 321. Basal dehiscence of Jussiaea. 322. The same in Cinchona. 323. Apical
dehiscence of Ladenhcrgia. 324. Dehiscence by apical plug (6) in Berlholetia. 325. Apical dehiscence
of Psyllocarpus. 32C. Oblique dehiscence of Slaelia. 327. Partial dehiscence of Jeffersonia. 328.
Dehiscence by apical pore in Siphocampylos,
through the ventral suture, which it more frequently does not, the
dehiscence will be Incomplete and the carpels may even act as separate
indehiscent fruits. If dehiscence occur at the dorsal suture (Fig. 315)
DEHISCENCE 115
it must separate the wall of the cell into two parts, and this form is
called Lociilicidal dehiscence. By an intermediate form, the dehiscence
takes place at the point where the septum joins the outer wall (Fig. 317),
the IMarginicidal form. Various other modifications and combinations
of the two forms may be discovered, but do not call for a notice in this
work.
Mechanism of Dehiscence.— Dehiscence is secured by a peculiar adap-
tation of the fil)ers to the other tissues and to the form of the fruit.
Incomplete Dehiscence. — \^arious forms of imi)erfect or incomplete
dehiscence are those in which it commences at the apex and fails to
extend itself to the base, as in Cerastium (Fig. 318) and EvcalyjJtus
(Fig. 319), or in which it commences at the base and extends only
partially toward the apex, as in Jnssiaea (Fig. 321) and in Cinchona
(322). Important pharmaceutical decisions have rested upon the
question of basal or apical dehiscence. The true Cinchona barks have
all proceeded from species whose fruits dehisce as represented in Fig.
322, while those of the trees yielding the false barks dehisce as repre-
sented in Fig. 323.
Syecial Terms for Dehiscence. — The manner in which true dehiscence
passes into false or transverse dehiscence, called Circumscissile, is well
displayed by Figs. 325, 32G, and 320, viewed in the order named, all
illustrations of closely related plants. A very curimis form of special
dehiscence is that of Jeffersonia (Fig. 327).
Rupturing. — Dehiscence is not the only method by which fruits
open to discharge their seeds. Rupturing fruits are those which oj)en
by an irregular line.
Dehiscence by Pores. — Some portion of a pericarp may decay quickly,
leaving an opening, or the same result may be secured by excessive
shrinkage in drying of the more delicate tissue of some part of the
Pericarp, as in Fig. 328. Openings of this kind are called Pores. Our
consideration of this subject will close with an illustration of the fruit of
the Bcrtholctia, or Brazil-nut (Fig. 324). The apex of this enormously
thickened and strongly hardened pericarp consists of a small circular
portion coiniected with the remainder by a circle of tissue which quickly
decays, making the former removable as a plug and thus leaving an
apical pore.
CHAPTER XI
CLASSIFICATION OF FRUITS
A PERFECT or even fairly satisfactory classification of fruits has never
been presented, and this is impossible, except through a complete
revision and uniform agreement of terminology, based upon a uniform
set of principles. A classification of some sort is, however, an essential
in pharmaceutical botany, and such an one is here presented as appears
most serviceable to those for whom it is intended.
Two Principles Involved. — Among all the various systems which have
been proposed, two fundamental principles have been observed — first,
the morphological structure; second, the physiological features. By the
first, fruits have been classed according to the character and number
of the parts entering into their formation and the modifications which
these have undergone in fructification; by the second, according to the
structural and functional characters as seen in the complete fruit,
without regard to their mode of origin. As characters of the latter
kind exist for the sake of the offices which they are to fulfil, it is clear
that physiology forms the basis of the latter method of classification.
Although it is impracticable to follow either system without some regard
to the other, it may be said that to follow in the main the morphological
plan is the more scientific, the other the more convenient and the more
practical, especially in economic work. The latter is, therefore, the plan
which is here adopted. Fruits possessing pericarps fitted for transpor-
tation (a of our table) will then form the first of our two classes, while
those fitted for discharging their seeds i'??. situ upon maturity will form
the second {e of the table).
F'or a few fruits not readily introduced to this key, and for some
exceptions, the explanations which follow may be consulted:
Fruits with pericarp designed for transportation (a).
Fruits with pericarp not designed for transportation (e).
f With fleshy pericarp (Carnose) (b).
( With non-fleshy pericarp (Siccose) (c).
[ With seeds embedded in a soft endocarp (g).
\ With seeds enclosed in a putamen (h).
nvo I'lilXCIPLES INVOLVKI) ]]?
f With ;m (Midosiiig involucre, at least hcforc maturity (/).
( Without an enclosintj iiixolucre [d].*
\ AVrticall\- (JixisiMc in onc-sccdcd j)arts (/).
I A one-set'ded ]);irt resulting from such division (j).
I Transversely divisible into one-seeded joints (n).
Not divisible into one-seeded ])arts nor the produet of such
I di\-ision (/,•). ^
Not transversely dehiscent (/).
Transversely dehiscent (f/).
Monocarpellary (?»)•
Dicarpellary, the valves sei)arating from the placentae (o).
I Not monocarpellary nor dicarpellary, with valves separating
[ from placentae {y).
r Soft throughout Berrv.
•j' With a soft, tough rind Hesperidium.
I With a hardened rind Pepo.
^ Putamen of bony hardness; solitary Drupe.
Putamen of bony hardness; one of several which are
coherent Pvrene.
Putamen of bony hardness; one of many which are
non-coherent Drupelet.
Putamen thin and tough Pome.
Schizocarp
(If dicarjx'llary, with a cari)ophore .... Cremocarp).
Part of a cremocar]j ]\Iericarp.
Not part of a cremocarp . . . .Coccus, Xucula, or Nutlet.
Dehiscent, the vahes separating from the two
placentae :\Iost Silicles.
With thin, winged pericarp Samara.
With inflated pericarp Utricle.
Pericarp, thickish in view of its size, not inflated,
sometimes winged Akene.
r A non-glumaceous involucre, with contents (dans.
I A one-seeded fruit from a glans Kut.
I A glumaeeous involucre with contents . . . A few Spikelet.s.
I A one-seeded fruit from a spikel(>t Caryopsis.
f Dehiscing by one suture only Follicle.
I Dehiscing by both ventral and dorsal sutures . . Legume.
I (When spirally coiled ("ochlea).
Exceptions occur.
118 CLASSIFICATION OF FRUITS
n . Loment.
^ I Elongated Silique.
I Short Some Silicles.
y Capsule.
q Pyxis.
The fact, as stated above, that custom has not been uniform in the
application of the principles of classification leading to the above terms,
so that the latter are not employed in the same sense in different botan-
ical writings, renders it necessary that such a key as that presented
should be supplemented by a detailed consideration of the limitations
and modifications of each class of fruits.
The Berry (Figs. 281 and 310). — A fruit with a pericarp fieshy through-
out, with the exception of the epicarp. Good illustrations are the grape
and the belladonna. In these, the fruit contains little or no cavity
and the seeds are embedded in a soft pulp. This is the typical form,
from which we see a variation in the Tomato, in the direction of a
central cavity, which in the Capsicum becomes complete. The latter is
frequently called a capsule and connects the berries with the latter
class, but it is more properly grouped with the berries. A similar
modification, though more slight, is found in the checkerberry (Fig. 303)
and the cranberry. The term has also been applied to the pomegranate
and similar fruits, but these, however soft within, possess a distinctly
hardened exocarp and are not true berries. As will be seen farther on,
comparatively few of the fruits which are designated as berries in
common parlance are really such. The berry may possess one or more
cells.
The Hesperidium (Fig. 329) . — A berry-like fruit with a soft, but tough
rind. The term has never been applied to other fruits than those
related to the orange and lemon. They are several-celled.
The Pepo (Fig. 332). — A berry-like fruit in structure, usually hollow
and with an indurated rind. It is one-celled. Good illustrations are
the pumpkin and melon, and the application of the term is by most
authors restricted to the fruits of that family (the Ciicurbitaceae) ;
but it is entirely proper to extend it to such very similar fruits of other
families as the Calabash (in the Bignoniaceae) and the Pomegranate
(in the Punicaccae).
The Drupe or Stone Fruit (Fig. 333). — A fruit with a sarcocarp and
epicarp and a single thick bony putamen. Although typically one-celled
and one-seeded, the term is applicable to similar fruits with several
THE SCIIIZOCARP
119
cells all enclosed in a single sarcocarp, bnt each seed possessing its own
putaiuen. Each jiiitamen with its own seed is then called a Pyrena or
Pyrene. Familiar illustrations of the tyi)ical drupe among medicinal
plants are the ])rune, sumach and pepper, and of the several-celled
form that of the RJiamnus, (Fig. 331) and the Phytolacca. As in most
classes of fruits, we find liere a gradation into other classes, most com-
monly into the Schizocarp. A peculiar fruit, in its general structure
related to the drupe, is the so-called legume of the tamarind, which
possesses an exocarp similar to that of a pepo, a distinct edible sarco-
carp and a crustaceous endocarp or putamen containing several seeds
(Fig. 307).
J^^.
33X.
JJJ.
Fig. 329. The hesperidium (lemon). 330. Sehizocarp of Urena. 331. Compound drupe, with
detached pyrena, of Rhamnus. 332. Transverse section of a pepo. 333. The drupe (plum). 334.
Dicarpellary sehizocarp of Labiatae.
The Psrrena (Fig. 331).- — (Already considered under Drupe.)
The Drupelet (Fig. 305, a). — Diifers from the Fyrcna in that it pos-
sesses not only its own separate putamen, but a sei)arate sarcocarp as
well. It is one of many small (Irui)es belonging to an aggregate or
multiple fruit.
The Pome (Fig. 308). — A fleshy fruit with a tliin chartaceous or cartil-
aginous putamen. It is several-celled. The term is commonly restricted
to fruits related to the ai)i)le.
The Sehizocarp (Figs. 2SS, 3.'>0, and 334). — The typical sehizocarp
should be delined as a fruit which divides septicidally at maturity into
one-seeded carpels. Because, however, schizocarps frequently vary in
the constancy and completeness with which they undergo this process,
they are defined as "divisible," rather than "dividing." There are,
moreover, cases in which they divide into one-seeded ])arts of cari)els.
The comprehensive definition, therefore, should be "dry fruits septi-
120 CLASSIFICATION OF FRUITS
cidally divisible at maturity into one-seeded parts." Schizocarps are
commonly provided with appendages for wind-transportation or for
transportation by mechanical adhesion to passing bodies. Those forms
which, as above stated, are intermediate toward drupes are to be
classed in one or the other class, according to whether such appendages
for distribution, or that of an edible pericarp, is the more pronounced.
Even schizocarps which are not cremocarps may possess a carpophore,
as in geranium, though commonly they do not.
The Cremocarp (Figs. 247 and 288). — A di-carpellary schizocarp, the
carpels attached toward their summits to a slender carpophore, from
which they usually only incompletely separate at maturity. The term
is restricted to the fruits of the UmbeUiferae. They are commonly
provided with appendages for fixation to passing bodies, frequently
for wind-transportation, and not rarely combine these two methods
of distribution. {Coniiim, Celery, etc.) There is no class of fruits which
possesses a greater importance in pharmacy, and hardly any whose
histological features are of greater interest. The plane of separation is
called the Commissure, a term applicable to a similar plane in other
fruits. (See Mericarp.)
The Coccus, Nucula, or Nutlet (Fig. 330, a, and Fig. 334, a).— One of
the divisions of a schizocarp, and its nature has been explained in con-
sidering that group. The term nutlet is commonly applied when the
pericarp is hard and close to the seed.
The Mericarp (Fig. 247, either half). — One of the halves into which a
cremocarp is divisible. Occasionally they are self-separating at matur-
ity, but usually only incompletely so. They are one-seeded and possess
a completely adnate calyx and disk. The pericarp almost uniformly
possesses external appendages in the form of five or nine ribs, as is well
shown in cross-sections (Fig. 335, h). When nine, they are commonly
of two forms, alternating with one another. A part or all of them are
much subject to extension into variously appendaged or pinnatifid
wings (Fig. 336, a). Internally, the mesocarp is almost uniformly
traversed upon both the faces and the backs of the carpel by tubes
called Vittae (Fig. 335, a), commonly with suberous walls and filled
with volatile oil. The dorsal vittae alternate in position with the ribs.
Upon thin transverse sections these oil-ducts or vittae appear as per-
forations, and as to their number and position serve the most important
purposes in diagnosis and identification, as do also the ribs. These
fruits are dorsally compressed when broader from right to left (Fig.
336), laterally compressed when broader in the opposite direction.
THE AKENE OR ACHEMUM
121
IMericarps are of three classes: (I) The Coelospermous, characterized
by the possession by the seed of a concave face (Fi^'. '.VA7, a); (2) the
Caiiii)yIosi)ernK)iis, characterized by the ])()ssessi()n of a loiigitiuHiially
grooved face (Fig. .'i'iS, a); and (3) the Ortliospermous, possessing a
plane face (Fig. '.V.]P>).
The Silicle. (See Sili(nie.)
The Samara.— All iiulciiiscent fruit witli a winged i)cricarp. "^I'liey
are commonly one-seeded, as well as one-carpel led, but may be more.
Typically, it is the ovarian wall or the tube of an adnate calyx which
develops the wing, but there is no reason why the term should not be
extended to include similarly transportable fruits with wings consisting
of the accrescent limb of a calyx (Figs. 288 and 289), or corolla (Fig. 291),
or a surrounding alate bract (Fig. 292). Commonly the samara possesses
but a single wing, unilateral, as in the ash (Fig. 3.')9), or circular, as in
the elm (Fig. 287), but not rarely more than one wing is present, as in
the maple (Fig. 340), or many Malpighiaceae (Fig. 342).
—-a
337
Kig. 335. Transverse section of an orthosperinous niericarp:
pressed mericarp, two of tlu> ribs winged. 337. Coelospermous
spermous mericarp of Conium.
33<S.
vitta; 6, rib. 330. Dorsall.v o(
L-riearp of coriander. 33S. Camp:
The Utricle (Fig. 341). — A one-seeded indehiscent fruit, the seed
enclosed in a thin, bladdery or inflated pericarj). It is commonly one-
celled, but occasionally several-celled. Ordinarily, utricles eventually
become irregularly rujjtured, l)ut in a few forms there is a regular
ventral opein'ng, ap])r()aching toward dehiscence.
The Akene or Achenium ( Figs. 71 to NO and ;M 1). A small, indehiscent.
one-seeded, seed-like fruit, the pci'icnrp soiiicw liat thickened and
entirely distinct from the (Miclo.scd seed. The aki-ne varies in many
directions toward other fruits. In many cases the pericarp is inclined
to be flesln- and in a few it tends toward dehiscence, thus sinuilating a
122
CLASSIFICATION OF FRUITS
follicle. Some forms of the akene are distinctly winged, so that they
might, but for the relationship of the species yielding them to akene-
producing species, be with equal propriety classed as samaras. They are
in nearly all cases provided with some means for securing wind-trans-
portation or for attaching themselves to passing bodies, and yet there
are numerous cases in which such appendages have become entirely
obsolete. For these reasons, it becomes a matter of extreme difficulty
to frame a definition at once comprehensive and delimiting fpr this
group. The inferior akene is sometimes distinguished bj^ the term
Cypsela (Figs. 74 to 80).
Fig. 339. Samara of ash. 340. Of maple. 341. Utricle. 342. Several winged samara of Mascaffraia.
343. Vertical section of anthodium. 344. Vertical section of akene of buttercup. 345. Same of the
glans of black walnut. 346. Glans of Fagus, or beech-nut.
Note should here be taken of the fact that the latter is characteristic
of the largest of all families, the Compositae, in which the akenes of
the head are massed and partially, or sometimes completely, surrounded
and enclosed by an involucre, the whole constituting a multiple fruit to
which the name Anthodium (Fig. 343) has been applied. The anthodium
varies greatly in its character. Although usually many-flowered, it is
commonly few-, or even in rare cases, one-flowered. In those cases in
which the involucre completely encloses the akenes, it is commonly
appendaged for distribution in an entire condition, as in the burdock.
This condition connects the anthodium with the glans and the contained
achenium with the nut. Indeed, it is almost impossible to distinguish
structurally between fruits representing these two classes, as, for instance,
those of Xanthium and Fagus.
The Glans (Figs. 345 and 346). — A fruit consisting of an accrescent
and partially or (commonly) completely enclosing involucre containing
THE LEGUME 123
one or more nuts. The involucre may be dehiscent, as in the chestnut
and hickory-nut, or indehiscent, as in the black wahuit (Fig. 345). In
some of its forms, the involucre of the glans tends to become fleshy.
Inasmuch, however, as the design of such pseudo-flesliy pericarps is
not that of subserving transportation by their f(K)d-])r()i)erties, they are
more appr()i)riately regarded as non-fieshy. Wliile dcjKMiding, Hke the
grasses, upon their gregarious habits for perpetuation, nut-yielding
plants are apparently in many cases distributed by the rounded form of
their coats and the readiness with which they are transported bj^ flowing
water.
The Nuca or Nut (Figs. 345, a, and 340, a). — The relationship of the
nut and its glans to the akene and its anthodium has already been
pointed out. The nut is in all cases much larger than the akene and its
pericarp commonly much thickened and very hard.
The Spikelet (Fig. 347). — A fruit possessing a glumaceous involucre
and pertaining to the Gramineae (grass family) and related orders.
This class of fruits, like the glans and nut, connects those fruits which
are adaj^ted to transportation with those which are not. Although,
in general, these plants depend for their perpetuation upon a highly
gregarious habit rather than upon provisions for distribution of their
fruits, yet the spikelets of some grasses are unmistakably so designed,
and are transported with their caryopses enclosed in the glurhes.
The Caryopsis or Grain (Fig. 348). — A seed-like fruit produced in a
spikelet, the oxarian wall and the seed-body closely adnate.
The FoIUcle (Fig. 349). — A monocarpellary fruit dehiscing by one
suture only, this the ventral, except in rare cases.
The Legume (Fig. 350). — A monocarpellary fruit, non-fleshy and
dehiscing by both ventral and dorsal sutures. Notwithstanding the
definition thus given, we have to record the fact that in accordance with
a different principle and construction, the title includes all fruits of the
natural order Leguminosae. It, therefore, becomes necessary to point
out that the fruits of this family are extremely variable, and this in
directions which frequently carry them widely away from both the
structural and the physiological characters of the legume. The pecu-
liarities of the tamarind have already been pointed out. In the fruit
of the Inga the dehiscent legume is filled with a large amount of juicy,
edible pulp, in which the seeds are embedded. In other species this
pulp is replaced by one of a powdery consistency, while in others it is
fleshy or subcorneous. A great many legumes of this family are not
only indehiscent, but winged and one-seeded, and thus are true samaras.
124
CLASSIFICATION OP FRUITS
The fruit of tlie Dipteryx is one-seeded and is dehiseent, but the peri-
carp is enormously thickened and first flesliy, then spongy. That of the
Cassia Fistula lias its seeds enclosed in a pulp and partly separated from
one another by transverse septa. It is thus apparent that many
legumes pertain to our first, rather than to our second, division.
'•^SZ
'3S4.
3SS.
JS6.
Fig. 347. Spikelet of a grass. 348. Caryop.sis from last. 349. Follicle of Asclepias. 350. Legume
of pea. 351. Loment of Aeschynomene. 352. Loment of Sophora. 353. Cochlea of Prosopis. 354.
Silique of Cardamine. 355. Silicle of Aethiomena. 356. Silicle of Hexaptera. 357. Silicle of Succowia.
358. Capsule of poppy.
Two distinctive forms of the legume have become dignified by the
application of special names, as follows:
The Loment (Figs. 351 and 352) is a leguminous fruit which may or
may not be dehiscent, but which is separable at maturity by transverse
divisions into one-seeded parts. In the Aeschynomejie these parts are
adapted to fixation to passing bodies, or occasionally also much flattened
and expanded to act as samaras. In the Soyliora (Fig. 352) the joints
are smooth, hard and rounded, and highly elastic, so that, in falling
upon the stony soil, they are adapted to bounding and running to a
considerable distance. The term loment has also been extended to
include those siliques which display a similar character.
The Cochlea (Fig. 353). — A legume which is spirally coiled.
THE SYCONIUM
125
The Silique (Fifj. 354). — A (li-('ar])cllary deliiscent fruit, the two valves
separating- t'roiii the mar<^ins of tiie phieentae at maturity, leaving the
latter attached tt) the torus and to a false septum, whieh divides the
siiicpie into two ])arts. The ])riii(i{)al modification of the silique proper
is into the loment-like form which we have already considered. These
loment-producing ])lants are commonly found in the vicinity of water,
and their fruits are adaj)ted to transportation by this method. A more
im|)ortaiit modification is into:
The Silicle (Fi^s. 'Ar>r^ to 357). — 'J'his difVers from the siH(iue not only
in being short and broad, but in possessing ordinarily some form of
adaptation to wind or other transportation, thus belonging in our first
class.
The Capsule (Figs. 318 to 238).— The typical capsule is to be defined
as a di- to polycarpellary longitudinally dehiscent fruit. From the
typical form, however, it varies in several directions to such a degree
SS^.
J60.
^6i
<36Z
Fig. 359. Giilbalus of ./i/Nipcrus. 300. Strobile of Picca. 3()1. Strobile of hop. 302. Syconium of
fig. 303. Pyxis of henliano.
as to render it impossible to frame a perfect definition. The capsule
of the poi)py (Fig. 358) opens by a number of small pores at the summit,
and this is true of many other forms. In other cases the mode of opening
is by various forms of irregular dehiscence intermediate between the
longitudinal and tlic circumscissile. Finally, w(> must note that many
fruits, like those of some species of Passljlord, which possess no regular
or natural method of ()i)ening, are still classed as ca])sules by systematic
botanists.
The Pyxis (Fig. :!().')). — A circumsci.ssily dehiscent fruit.
The Syconium (Fig. 302). — A fruit consisting of a hollow branch,
becoming fleshy, its inner surface the recejitaclc for many >niall,
one-seeded, akcnc-likc fruits.
126 CLASSIFICATION OF FRUITS
The Aeterio (Figs. 304 and 305). — An aggregate fruit, with an accres-
cent fleshy torus and many crowded pistils.
The Strobile (Figs. 360 and 361). — A multiple dry fruit, its elements in
the form of imbricated scales.
The Galbalus (Fig. 359).— A fruit similar to the last, but the scales
fleshy or much thickened above, so that the form becomes more or
less globular.
In conclusion, it may be remarked that to assign a name to a fruit
is insufficient in most cases, especially in those of aggregate and
multiple fruits, to designate its character.
CHAPTER XII
THE SEED
Changes in the Ovule. — As in the case of the parts entering into the
formation of the pericarp, so in that of the part forming the seed —
namely, the ovule — it is well to precede our study of the changes which
it undergoes by a consideration of the objects to be attained thereby.
Development of the Embryo. —
The essential feature of the seed is
the possession as one of its parts
of a more or less rudimentary
plant, developed from the fertil-
ized oosphere, and known as the
Embryo, and capable of remaining
for a more or less extended period,
before germination, in a state of
suspended animation.
The development of the embryo
commences with the division of
the fertilized oosphere into two
cells, each of which grows and
becomes capable of itself dividing
similarly. The result of such cell-
propagation is the production of
a tissue and of a body which
becomes elongated through suc-
cessive transverse divisions of its
cells, or certain of them, and
broadened by their longitudinal
division. Several progressive forms reached by
this ])r()cess arc sliown in Figs. 305 to 3()8.
Provisions Required by the Embryo. — During the period intervening
between the beginning and the completion of seed-formation the
embryo requires nourishing, and provisions for this constitutes the first
requirement of the process. The further development and growth of
J66.
Figs. 364 to 368. Figures illustrating develop-
ment of the embryo; the vertical chain of cells is
the pro-embryo, the uppermost of them becomes
the caulicle and the enlargement the cotyledons.
the
ibr'
(hi
ring
128 THE SEED
the embryo, between the time of germination and that of absorption by
it from the external world, calls for additional nourishment. This can
be met only by the storage as a part of the seed of an additional food-
supply.
Protection of the seed-contents during its development is only partially
afforded by the pericarp, and this office is supplemented by the coverings
of the seed itself, while its similar self-protection between the periods of
maturity and germination is a manifest necessity.
The transfer of the mature seed to the point of germination, or its
dissemination, and its fixation in a favorable site, have already been
referred to. We have seen that in many cases these offices are not
provided for by the pericarp, and we must look for such provision to
the seed itself.
Parts of a Seed. — The parts of the seed by which these several offices
are performed we find to be as follows:
The Perisperm.- — The source of food-supply during the germination
of the macrospore and development of the gametophyte we have seen
to be the portion of the nucellus external to the embryo-sac. Usually
more or less of this material remains during at least the earlier period of
the development of the embryo and contributes to the nourishment
of the latter. Occasionally it persists even in the seed condition. It is
then known as the Perisperm.
The Endosperm. — Inside the embryo-sac a further store of nutriment
is caused to develop as a result of fertilization, this constituting the
chief supply of the growing embryo. More or less of this also may
persist, and usually does, upon the maturity of the seed. It is known as
the Endosperm.
Albuminous and Exalbuminous Seeds. — As the embryo develops, it
stores within its own body more or less nutriment. At maturity we
may find that the entire store of nutriment has thus been transferred
to the body of the embryo, and the seed is said to be Exalbuminous, or
we may find more or less endosperm or perisperm, or both, when the
seed is said to be Albuminous, and this external nourishment is known
as the Albumin. In only a few seeds used in medicine does the albumin
consist in any part of perisperm. The chemical nature of the albumin
is extremely variable. It received its misleading name because of the
similarity of its function to that of the albumin of the egg.
Protection. — Protection to the embryo may be afforded by the albumin
when that is of the required consistency or composition, the conditions
of the latter being a mere parallel of those already considered under
77/ A' IIIU'M 129
tlic siil)j(>ct ol" the pericarj). Moi-c IVcciiuMitly, Iiowcxcr, it is -ccurt'd
(Mitircl\' tlir()iiii;li the coats of tlit' seed.
The Scrd-codf.s. — Those may con-csijoiid to the coats of the o\ul(',
though usually tiie i)riiniiie is found to have (lisa])])('ar('d. When it
persists it takes the name of Tegmen, or Endo])leura, the secundine
hecomino; the Testa, or Exopleura. Rarely tlie secundine also disa])i)ears
and the seed is Naked. The seed will also be naked when ])roduced from
a naked ovule.
Tlir Micropiilc. — When one or both of the coats persists, the point
where the foramen, now closed, existed becomes the Micropyle.
The Aril. — Frecjuently the develoi)ment of a new coat external to
the others is induced by fertilization, and this is known by the general
name of Aril. If it develop from the chalaza or a lower point, it is called
an Arillus, or True Aril; if from the micropyle, an Arillode, or False
Aril.
Dissemination. — The provisions of the seed for securing dissemination
are in most res])ects comparable with those afi'ecting the pericarp.
Wind-distribution is preeminent, that by fixation to passing bodies is
fre(iuent, and that by means of an edible coat is rare.
Fixation. — The fixation of seeds disseminated without the pericarp is
favored by their small size, enabling them readily to enter crevices and
cavities, and by peculiarities of surface which fa\()r the same process.
The large number and importance of medicinal seeds lend great
importance to their study by the i)harmacogn()sist, and this is especially
true of the histology of all their ])arts. Inasnnich, however, as the
subject of histology has been referred to a se})arate ])ortion of the work,
we shall here consider only such characters as can be distinguished
by means of an ordinary lens.
The Hilum. — The hiluni is in most cases readily perceptible, but is
occasionally found only by minute examination. It is to be studied as
to its position, size, form, surface, and color. Its position is sometimes
fixed with reference to the form of the seed, as at the larger or smaller
end, upon the l)road side or on the edge, as well as with reference to the
micropyle, adjoining it, at the ()])posit(> end or at some intermediate
])oint. It is the last-mentioned character which detennines the class
of seed as to itstr()])ism (see Ovule). In size the liiluni may b(> a slight
point, or it may cover a considerable jjortion t)f the surface. Its form is
frequently characteristic, as heart-shaped (Fig. '.M()) or lim-ar and
channelled, as in Fig. '.Vi\. Its color fre(iuenlly (lifV(>rs markedly from
that of the remainder of the seed.
130
THE SEED
The Raphe. — The raphe, extending from the hihim to tlie chalaza
when these do not coincide, is ordinarily not readily perceptible upon
the surface. When it is so, as in Figs. 372 and 373, its appearance is of
great diagnostic value and must be closely scrutinized. The chalaza
in its simple form calls for lio special attention.
The Strophiole. — If, however, an enlargement appears at this point
(the Stroyliiole, Fig. 374, a), it must not be overlooked. The strophiole
may develop into the arillus (Fig. 375), a partial or complete covering,
and its characters call for the same attention which is requisite for the
testa.
JM <^^J
Fig. 369. Vertical section, seed of Cardamomum. 370. Cordate hihiin, of Cardiospermum. 371.
Linear hilum of Calabar bean. 372. Central hilum of nux vomica. 373. Seed of Niederlinia with
conspicuous raphe and funiculus. 374. Seed of Hypericum with large strophiole at a. 375. Seed of
Hanetic with partial arillus. 376. Pitted seed of Sanvegesia. 377. Reticulate seed of henbane. 378 .
Reticulate-pitted seed of tobacco. 379. Finely reticulated seed of Datura. 380. Seed of Ricinus,
with caruncle at a. 381. Arilled seed of Myrislica. 382. Seed of Acorus, with peculiarly appendaged
micropyle.
The Testa. — The testa is not wanting in any medicinal seed. In
general it is not closely adherent to the underlying tissue, and it can
be readily removed. In its thickness, consistency, surface, color and
appendages it yields important pharmacognostical characters. It may
be pitted (Fig. 370), reticulate (Fig. 377), reticulate-pitted (Fig. 378)
or hairy (Fig. 372), and the minute characters of its pits, tubercles,
ridges, or hairs must not be overlooked. It may be dull or shiny, and
its color may be uniform or variegated (Fig. 379). Its luster or shade
of color is frequently of the greatest assistance in determining the age,
freshness, mode of preparing or preserving, or other conditions on which
the comparative medicinal quality of the seed depends.
THE TEGMEN
131
The Caruncle.- Tlu> ('iil;ir<;eiiu'iit at the iiiicr()])yle (tlic Canmcle,
Fig. 380, a) calls for the same scrutiny as the str()i)hiole. It may be
variously api)eM(la<j;ed (Fig. 382), and, like the latter, it may extend
into a partial or com})letc covering, the arillode. The arillus, or arillode
(Fig. 381), may he i)artial, as in nutmeg, or complete, as in the seed of
the Euonymus.
Appendages. — Appendages to the seed do not always take the form
of an aril of either class, nor is their origin confined to the points from
which the aril devel()i)s. Fither as aril or ai)i)endage from the general
surface, they exliibit a great variety of form, of equal importance with
,.«
383.
'''' iy?,si ^^
J94. '^os. jm.
-Wl
JUO.
JM
Fig. 383. Seed of Eiicharidiiim, with fringed margin. 384. Penicillate seed of Epilobium. 385.
Tufted seed of Pelrocoptis. 386. Finibriate-winged seed of Daitais. 387. Winged seed of Cinchona.
388. Pluniose-awned seed of Stroiihanthus. 389. A globose seed. 390. Lenticular seed of Lens.
391. Saucer-shaped seed of Lecanosperma. 392. Linear seed of Nepenthes. 393. A polyhedral seed
of Nolina. 394. Serrated seed of Akebia. 395. Reniforni seed of bean. 39G. Cochlear seed of Ilelio-
chnris. 397. Crescent-shaped seed of Menispermum. 398. A lobed seed. 399. Nutmeg, with the
albumin niniinutcd.
those which characterize the pericarp. Forms of especially frequent
occurrence are exhibited by Figs. 383 to 388. Important distinctions
sometimes exist between seeds bearing similar ai)])endages, as regards
the j)oints from which the latter originate, as in the case of strojihanthus,
false and true.
The general form of the testa is, of course, that of the seed, and calls
for terms applicable to the forms of solid bodies (Figs. 389 to 398).
The Tegmen. — The tegmen, when present, is extremely thin and tightly
adiierent to the nucellus, following closely all inequalities upon the
surface of the latter, and occasionally having its intruded folds caught
between the forming masses of the albumin and discernible upon
132
THE SEED
section of the latter as slender veins, giving us the so-called Ruminated
Albumin (Fig. :599).
The Albumin. — The albumin is characterized chiefly by its con-
sistency, being bony, as in the ivory nut and date; horny, as in nux
vomica; oily, as in the castor-bean and cacao; fleshy, mealy, etc. In
sectioning the seed, note should be taken of the presence, number,
position and forms of any cavities which may exist in it.
The Embryo. — The embryo calls for the most thorough and minute
study as a basis for systematic work, though for the pharmacognosist
only the more important details of its general structure need be con-
sidered. It has already been stated that it consists of one or more
phytomers.
4U2
Fig. 400. Circinate embryo of Campoma^H'.sfVi: /(, radicle; ca, caulicle- fo<, cotyledons. 401. Section
through seed of Gynocardia. 402. Centric curved embryo of Gynocramhe. 403. Centric straight embryo
of Frankeaia. 404. Germinating monocotyledonous embryo. 405. Embryo of Dipteryx with pinnatifid
plumule (pO- 406. Polycotyledonous embryo.
The Caulicle. — The chain of cells first formed is the pro-embryo, and
this is supposed to act in transferring nourishment to the embryo.
At its end, next to the cotyledons, develops the first internode of the
coming plant, and this becomes the caulicle (m in Figs. 400 to 403),
in old works denominated the "radicle."
POSITION OF THE EMBRYO 133
The Radicle. — ^Tlie Radicle (// in the last-iianu-d (i<,nircs) is tlie extreme
tip of the cauliele, which points always in the direction of the micropyle.
From this i)()int the root is to be developed. The embryo may consist
of nothing fnrther than the cauliele, and even this may be of the most
elementary character.
The Cotyledons. — Ordinarily, however, there develops at the node
(tiie point opposite to the radicle) one or more Cotyledons, or Seed-
leaves {cot in the figures).
Monocotyledons, Dicotyledons, and Polycotyledons. — Most seeds which
possess but a single cotyledon (Fig. 404) are grouped together in a
division of the Angiosperms, which for this reason are called Mono-
cotyledons, those with two in the Dicotyledons. A few plants, mo.stly
Gymnosperms, are ])()lyc()tyledons (Fig. 406).
The Plumule. — The highest plants of their respective groups develop
a second phytomer lying between the cotyledons, or if there be but one
cotyledon, mostly enwrapped by it. This is the Plumule (Fig. 405, jjI),
which shows the same variation in the degree of its development as
that which characterizes the lower. When its leaves are developed,
they bear a closer resemblance, as in the figure, to the mature leaves
of the plant than do the cotyledons, following out the law referred to in
our introduction. Among dicotyledons, the ])lumulc commonly pertains
to exalbuminous seeds.
Direction of the Radicle. — Terms used to indicate dirt'erent directions
of the radicle refer to its direction with relation to the fruit, its direction
in relation to the micropyle being, as has been stated, always the same.
It is Ascending when it points toward the apex of the fruit. Descending
when in the opposite direction, and Horizontal when intermediate.
The latter form is Centrifugal when pointing toward the perii)hery,
Centripetal when toward the axis.
Position of the Embryo. — The position of the embryo with reference
to the albumin is always highly cliaracteristic. It is Axile or Centric
when in the center of the albumin (Figs. 402 and 403), whether straight
or curved; Eccentric when within the albumin, but outside of its center
(Fig. 407); Peripheral when 1\ ing upon the surface of the albumin. In
the latter position it may be straight, sim])ly cur\ed (Fig. 4()S\ or
circinately coiletl (Figs. 409 and 410).
The relative sizes of the embryo and the albumin vary from those
in which the former is a mere sjjeck in a large mass of the latter to that
in which the proi)ortions are reversed, or in which the ;iil)uniin is
entirely wanting.
134
THE SEED
Forms of the Embryo. — The eml)ryo should in all cases be dissected
from the contiguous parts and the relations of its parts to one another
made out. It may be straight, variously curved, crumpled (Fig. 411),
or variously folded. In the latter condition the radicle may be brought
into juxtaposition with the edges of the cotyledons (Accumbent, Fig.
413) or with the face of one of them (Incumbent, Fig. 412), One
cotyledon may enwrap the other (Fig. 414). When a single cotyledon
partly encloses the greater portion of the remainder of the embryo
it is sometimes called the Scutellum (Fig. 415). Some of the terms
applicable to the consistency of the albumin are also applicable to that
of the cotvledons.
Fig. 407. Eccentric curved embryo of Galium. 408. Peripheral simply curved embryo of Bosia. 409.
Peripheral circinately curved embryo of ^cAj/raniAes. 410. Circinately coiled embrj'o. 411. Crumpled
embryo of Suaeda. 412. Incumbent radicle of Calepina. 413. Accumbent radicle of Megacarpaea.
414. Embryo of Dryobolanops, one cotyledon enwrapping the others. 415. Embryo of barley with
scutellum (s).
The Taste. — Finally, the pharmacognosist will find it of importance
in the case of seeds possessing a characteristic taste to inform himself
as to the part, if any, to which such taste is restricted.
Reproduction Completed. — With the production of the seed, containing
a distinct living individual separated from the parent and fitted for
independent existence, reproduction can strictly be considered as com-
pleted, although the progeny is still in its infancy and its form not yet
perfect.
Similarity of the Seed to the Bud. — The analogy between the seed and
the bud is apparent. Each consists of one or more vegetative units
ready to develop under proper conditions into a perfect semblance of
the parent, and each is provided with a store of prepared nourishment
EXAMINATION OF THE SEED 135
to sustain it until able to manufacture such for itself. The distinction is
in the radically different modes of origin, and in structure, leading to
different powers of reproduction.
Examination of the Seed. — ^In the examination of the seed for the
determination of the {'haracters above defined, the most certain method
is the examination of transverse and longitudinal sections by the use
of the compound microscope, as will be explained in Part II of this
work. It is not difficult, however, to determine all the essential char-
acters of most seeds by the aid of an ordinary magnifying glass. The
superficial characters of the seed should first be examined in the dry
condition, after which it should be thoroughly soaked for a period
varying from a few hours to several days, or the preparation may be
hastened by gently boiling. Its superficial characters must be then
again examined and compared with those previously observed. Espe-
cially must the relative positions of chalaza, hilum, micropyle, and raphe
be accurately determined. A longitudinal incision is then to be made
along one side and the coats removed, separately if possible. The
examination of the testa, with the discovery of a much thickened line,
will sometimes disclose a raphe which was overlooked in the superficial
examination. In removing the coats, great care must be taken to avoid
wounding the nucellus. The position of the embryo with regard to the
albumin, if any, and its general form can now be readily ascertained.
The embryo should finally be removed and its several parts studied.
The most common error made by students is the mistaking of small
one-seeded fruits, such as mericari)s, akenes, and nuculae, for seeds, with
the result that all of the parts and their relations are confused. The
substitution of such terms as conium-fruit, coriander-fruit, burdock-
fruit, and hem])-fniit for the incorrect terms "Conium-seed," etc., in
common use, should be encouraged by all educated i)harmacists in
their daily business relations, as a correct idea of the natiu'e of the jiarts
employed lies at the foundation of a proper understanding of their
composition and i)r()j)crties.
CHAPTER XIII
GENERAL STRUCTURE OF ROOT AND STEM
The Development of Different Tissues. — The de\'e]opment of the stem
commences with the formation of the embryo, by the process explained
at the beginning of our study of the seed. So long as the cells produced
by this process are the same in kind, the body consists of but one tissue;
but through differentiation and specialization among them, difi'erent
tissues are soon developed.
Meristem. — The power of cell-di\'ision and growth is lost by most
tissue after a time, while in other parts it persists permanently. Any
tissue or portion of tissue which possesses such power is called Meristem.
Tissue may cease finally to exert meristematic power, or it may resume
such power after a time. All meristematic processes cease upon maturity
of seed, recommencing with germination.
Degree of Development Attained by the Embryo in the Seed-condition. —
The point reached in the development of any plant-body in the embry-
onic condition — that is, at the maturity of the seed — does not depend
in any degree upon the amount or kind of tissue or tissues developed,
but altogether upon the habit of the particular class of plant. In some
embryos, tissue differentiation cannot be seen to have taken place at
the time of separation from the parent, while in others it has progressed
very far, though never (unless germination has occurred) to the pro-
duction of a true root. It is impossible, therefore, to fix upon any
particular developmental stage of stem-structure as distinguishing the
ungerminated embryo from the germinated plantlet. In the following
sketch of its development, then, no note is taken of the resting period
in the seed-stage, but the process is followed as though it were con-
tinuous from fertilization through germination and into the mature
condition of the plant.
Although of primary importance scientifically, and of great interest,
the phenomena of germination are not important from the standpoint
of pharmacognosy, and a mere outline of them is here given.
Vitality of Seeds. — Animation is probably not entirely suspended
during the resting period of the seed. That is, there is an apparent
GERMINA TION
137
iiitorc-luin<,^o of substance, due to vital action, hetweeu the seed and the
surrounding atmosphere, altliough c\treniel\' shght, so long as the former
possesses its vitality.
The evidence as to h-ngtii of time (hiring wliich seeds can retain their
vitaHty is extremely contradictory, and the greatest diversity of oj)inion
exists concerning this point. Our best authorities bclicxc that we have
no conclusive e\'idciic(> that the period is longer than about fifty years,
although, u])on the other hand, we have no positive evidence that it is
not ver\' nuich Jouiicr.
Germination. — ('oiidifions of (IcnnliKifioii.- (u-rniination dciiends
u])on (Da specific temperature, varying for seeds of dillerent species
and for those of the same species when they hav(> become" habituated
138 GENERAL STRUCTURE OF ROOT AND STEM
to essentially different climatic conditions; (2) a specific saturation, also
varying with different seeds — that is, the absorption of an amount of
water bearing a fixed ratio to the weight of the seed : (3) a partially fixed
degree of light exclusion; (4) the presence of free oxygen.
The Process of Germination. — Under these conditions, ready prepared
nutriment is dissolved, other forms become digested by special vegetable
ferments (Enzymes) present, heat is developed, cell-propagation and
cell-growth take place, and the development and growth of a plant from
the embryo commence. By the growth of the embryo, the radicle is pro-
truded through the micropyle, the rest of the body soon following and
leaving the embryo free from its coats, or the body may remain enclosed
in the coats for some time. The» radicle, if it does not already point
directly downward, turns in that direction and develops into a root
(Figs. 417 and 419). The cotyledons may then separate completely,
leaving the plumule or second phytomer to develop from the apex,
between them (Fig. 416), or the cotyledons may remain in contact, and
the plumule or second phytomer burst forth from between the bases
of their petioles (Fig. 418). The end of the embryo opposite to the
radicle, if it does not already point upward, turns in that direction and
develops as the apex of the stem.
The Epicotyl and Hypocotyl. — The stem above the cotyledons is called
the Epicotyl, that below them the Hypocotyl.
Cellular Development and Growth. — The cellular nature of develop-
ment and growth demands a general knowledge of histology for their
understanding, so that we shall here consider, so far as possible, only
the gross results of the processes, or such characters of the root and
stem as can be demonstrated by other than histological methods. Such
references to cellular structure as are here necessary are given rather
figuratively than technically. The mode of growth in root and stem,
and the structures resulting, are sufficienti}' different to require separate
treatment. Although the forms of structure liere considered as applying
to the root concern only flowering plants and the very highest of the
cryptograms, yet the description is applicable to all roots used in
medicine.
Structure of the Root. — Upon examining a transverse section of the
root in its rudimentary condition, it is possible to distinguish three
bodies of tissue exhibiting characteristic differences in their cellular
elements (P'ig. 420).
The Plerom, Pleriblem, and Dermatogen. — The central portion is
occupied by a solid cylinder called the Plerom (a). Outside of this
STRUCTURES DEVELOPED FROM THE PERIBLEM
139
there is a hollow cylinder called the Periblem (6), and still outside of
this and upon the surface of the root a second hollow cylinder, the
Dermatogen (c).
Structures Developed from the Dermatogen. — The last mentioned
develops a primary covorhig called the Ki)i(k'rmis (Fig. 422, a).
The Root-cap. — The ci)idermis consists in its earliest stage, and there-
fore at the very tip, of a number of layers of cells which protect the
apical growing point of the root, and is therefore called at that point
the Root-cap (Fig. 41 G, a-b). Toward the summit of the root-cap the
outer layers of cells successively wear off or are cast off, so that
the epidermis becomes reduced to a single thickness of cells.
Fig. 420. Diagram illustrating arrangement of ground-tissues of root: a, plerom; b, periblem: c,
dermatogen. 421. Plerom enclosed by endodermis (c), with first appearance of bundles: e, xylem-
bundle; /, phloem-bundle; g, medullary-raj- : h, pericycle; i, temporary pith. 422. The same in
a more advanced stage, the outer portions also present: a, epiderm; b, liypoderm; c, endodcrm (cortex
between b and c); e, xylcm-bundles now meeting at center; /, phloem-bundle; (?, medullary-ray; h,
pericycle; i, cambium of the primary phloem-bundle; y, of the primary xylem-bundle; 2, of the
primary medullary-ray.
The Ruot-hdirs and Pclij'croiis Layer.- — Here it frequently (lc\clops a
dense covering of Root-hairs which adhere tenaciously to the soil and
perform various processes connected with absorptit)n (Fig. 410, h-c).
For this reason, this portion of the epidermis of the root is known
as the Piliferous Layer.
The Epidermis Proper. — Still farther uj) these hairs have fallen
away, and the single layer, after slight modifications, becomes converted
into the epidermis i)roper. This has a variable duration in difl'erent
plants and is consequently found covering the root for a greater or less
distance upward. Almost always its duration is very short. It either
disappears altogether, being replaced by a structure (Periderm) devel-
()])c<l from the periblem, or in rare cases itself develops into the periderm.
Structures Developed from the Periblem. — The periblem of the root
develops into the Cortex (Fig. 422 between b and r), consisting of a
number, often a large number, of layers of cells.
140 GENERAL STRUCTURE OF ROOT AND STEM
The Ilypodermis. — Its outermost portion, usually of one layer of
cells, presents a different appearance from the subjacent layers, and
is the Hypodermis (Fig. 422, h) in the case of the root becoming the
Exodermis. The hypoderm lies against the inner face of the epiderm
(a), while that persists, l)ecoming afterward the superficial layer, and
persists for a longer or shorter period. Its characteristics are of great
importance in histological determinations.
The Endodermis. — The innermost layer of the primary cortex is even
more distinct in appearance than the hypoderm, and is the Endodermis
(c). It lies in contact with the outer surface of the structure developed
from the plerom.
Disappearance of the Primary Cortex. — The production of primary
cortex is quickly completed. If then the growth inside of it continues
indefinitely it, in most plants, involves the destruction and disappearance
of the primary cortex, which must be replaced by some other covering.
Promsion by Phellogen for a New 'Covering. — A new meristematic
region must then be established for the purpose of manufacturing such
a covering. This almost always arises in some part, and it may be in any
part, of the primary cortex. It is the Phellogen (Fig. 422, d). The
phellogen may be in the form of a continuous circle or the usual form
in that of blades or plates (d), variously placed and directed.
Periderm and PheUoderm. — Upon its outer surface the phellogen
develops corky tissue, the Periderm, and upon its inner a secondary
cortex, the PheUoderm. Occasionally it will produce only periderm or
only phelloderm.
Secondary Periderm. — As the periderm becomes impervious to the
nourishing fluids, it and all the tissues exterior to it must die, and may
be cast off, a new phellogen then appearing farther toward the interior
to form a new periderm, so that we may have successive periderms —
the primary, secondary, and so on. This process is comparatively' rare
in the case of the root, very common in that of the stem.
The Bork. — In such cases, the corky layers which become successively
superficial, observed in the scales of bark which peel off from tree-trunks,
constitute the Bork or Rhytidoma. Bork is called Ring-bork when it
forms a cylinder, Scale-bork when it occurs in detached plates. It must
be noted that the origin of the bork, and, as will be shown later, its
structural nature dependent thereon, will depend upon the depth at
which the phellogen develops. The same feature will also determine the
amount and character of the tissue, if any, existing between it and the
structure developed from the plerom.
STRUCTURES DEVELOPED FROM THE rJ.EROM 141
No Fibro-mscular TLs-suc Developed j'roin Perihieiii.— Su tissue
developed directly or indirectly from the j)eril)lein is in the form of
distinct and rej^ular bundles of vessels, though irregular and isolated
or anastomosinti tubes are frequently develojjed by it.
Structures Developed from the Plerom. The S1ele.~ The essential
characteristic of the body developed from the plerom of the root is
that it is invested by the endodermis and is free from any other endo-
dermal development in any part. It, therefore, constitutes a Stele
(all inside of c), which in the root is always in the form of a Central
Cylinder.
Differentiation in the Cells of the »S7t7f'.— The plerom exhibits at first
only sHght differences in the appearance of its cells (Fig. 420, a), and
a transverse section of it viewed with the microscope might be figura-
tively compared to looking down upon a honeycomb built in a cylin-
drical tin box, the latter representing the endodermis, and in longitudinal
section to a longitudinal section through the same. This constitutes
the Ground-tissue of the Stele. Farther away from the tip, however,
it would be found that groups of its cells (Fig. 421, e and/) had elon-
gated in a longitudinal direction, and these, to continue our illustration,
might be compared to bundles of pencils or quills set in the honeycomb.
Mingled among the elongated cells of the bundle, however, are many
which have not elongated.
Medullary Rai/.'i. — These bundles would be arranged in a circle
separated from one another })y more or less of the honeycomb tissue,
these sej)arating ])ortions corres])()nding to the Medullary Jvays of the
Stele (g).
The Pcriri/cle. — From the endodermis they would be separated by
one or more continuous circles of the honeycomb cells, corresponding
to the Pericyde or " Pericambium" (h). For a time there would also
be left a central jiortion (/), consisting of unchanged cells, forming a
temporary Medulla or pith.
The Vessels. — The elongated cells, which constitute the imj^ortant
elements of the bundles, are joined end to end with other similar ones
still farther uj) in the older jKirt of the structure. At first the enii walls
of these abutting cells sei)arate their cavities from one another, but
later these disappear in those of some bundles, becoming jjcrforatcd in
those of others, so that the cavities become more oi- less contiinious,
forming the Vessels, extending throughout the root and intoaiul through
the stem above. The bundles thus formed are thus of two kinds, aher-
nating in the circle.
142 GENERAL STRUCTURE OF ROOT AND STEM
The Xylem- or Wood-bundles. — Each of those of one kind (Fig, 422, e)
extends gradually toward the center by the successive development
there of vessels or cells associated with the vessels of the bundles. Upon
meeting there, the bundles, of course, cut off the previously existing
central communication between the medullary rays, which are now left
as isolated plates or wedges between the bundles, the temporary pith
being thus obliterated. These bundles, which meet at the center, are
known as the Xylem-bundles or Wood-bundles, and constitute the
wood}' portion of the root.
The Ducts. — The tubes formed as described above are the Ducts.
In a few plants which we have to consider, the Gymnosperms, no
series of cells lose their end-walls as above described so as to become
converted into continuous tubes or ducts, though they connect by
perforations.
The Phloem- or Sieve-bundles and Sieve-tubes. — The other bundles
(Fig. 422, /) which have been described as alternating with the xylem-,
or wood-bundles, possess as their important element those cells which
become connected by perforations in the form of sieves, and are known
as the Phloem-bundles.
Collectively they form what is known as the Sieve-tissue, or Cribrose-
tissue, of the plant, and their intercommunicating tubes are the Sieve-
tubes. This tissue characterizes the Gymnosperms as well as the
Angiosperms. The phloem-bundles do not extend toward the center, as
do the xylem-bundles, but stand isolated, each between two medullary
rays, which respectively separate it from the xylem-bundle upon either
side.
The Fibers. — In connection with the ducts, or their equivalents
in the gymnosperms, and the other tissues of the xylem-bundles, strong
fibers develop, the Wood-fibers, while in connection with the sieve-tubes
and other tissue of the phfoem-bundles very similar fibers, the Bast-
fibers, usually develop. The phloem-bundles, therefore, ordinarily
become Bast-bundles.
Fibro-vascular Bundles. — Vascular bundles in which fibers develop
are known as Fibro-vascular bundles.
Secondary Groivth of the Stele. — The condition now reached by the
root constitutes the completed primary structure of its stele. The
student should not fail to note that the primary structure refers only
to the very smallest roots, and that he need not expect to encounter it
in any roots in a condition to be used medicinally. His examination
of roots in Pharmacognosy will, therefore, relate to the secondary
CONTINUOUS MULTIPLICATION OF THE STRUCTURES 143
structure, an account of wliich will follow. With the production of the
primary structure, growth and increase in thickness may cease (most
]\Ionoc()tyledons), in which case the periderm changes which we have
recorded will not occur. On the other hand, secondary growth may
take place, in which case those changes are more or less completely
induced.
Development of the Cambium. — In such case, the cells touching the
phloem-bundles upon their inner faces and n])on their sides become
meristematic and proceed to produce xylem-tissue upon their inner
faces and secondary phloem upon their outer, in contact with the
primary tissue of that kind. Each such arc of meristem (Fig. 422, x)
becomes the Cambium of that bundle.
Completion of the Bundles. — At the same time the cells lying in contact
with the outer surfaces and with the sides of each xylem-bundle similarly
become a cambium for that bundle {y), and sometimes produce second-
ary xylem, upon their inner faces, in contact with the primary xylem
there, and secondary phloem.upon their outer faces. By these processes
each bundle which undergoes them, previously consisting of one kind
of tissue, therefore an incomplete bundle, comes to consist of both kinds
of tissue and becomes a complete bundle.
The Cambium-circle. — Connecting the cambium arcs of the adjacent
bundles, a cambium arc (2) forms in the intervening medullary ray, and
this produces secondary medullary ray tissue on both its inner and its
outer face. There is thus formed a continuous cylinder of cambium
(.r, y, z), though a somewhat irregular and wavy cylinder, standing
between the zone formed within by the primary and secondary xylem-
bundles and their intervening portions of the medullary rays, and the
outer primary and secondary phloem-bundles (when the latter develop)
with their intervening portions of the medullary rays. Although this
cambium forms a cylinder, as stated, it is usually referred to as the
" Cambium-ring," or " Cambium-circle," because it presents this appear-
ance in transverse section.
Continuous Multiplication of the Structures. — Provision is now nuule
for the growth of all portions of the stele. Additional complete fibro-
vascular bundles are now developed in the medullary ray spaces between
the others, fed by a portion of cam])ium in a similar manner. New
medullary rays also develop in the substance of the bundles. We thus
have developed upon the inside of the cambium-cylinder a cylinder of
xylem, solid except for the blades of medullary ray tissue ])enetrating
it nearlv to the center, and outside of the cambium-cvlinder a hollow
144 GENERAL STRUCTURE OF ROOT AND STEM
cylinder of phloem tissue or bast tissue, continuous except for similar,
but of course much shorter, medullary rays.
It has been said above that the portions of the cambium-circle
opposite to the primary wood-bundles "may" produce secondary
wood upon their inner faces and secondary phloem upon their outer.
While this does take place in some roots, it usually does not, only
pericycle tissue forming at those points on both the inner and outer
faces of the cambium.
The above constitutes the secondary structure of the root-stele, and
any further growth which may occur, except for the development of
branches, considered hereafter, is merely a continuation of the process
described as secondary growth.
The Annual Rings. — When an annua! resting-period in growth occurs,
the ducts of the xylem produced toward the close of the year's growth
will be conspicuously smaller than those produced at the beginning, so
that conspicuous Annual rings are produced in many woods.
The Duramen and Alburnum. — ^After a tree has attained a certain age,
the wood at the center dies, and becomes dryer and harder and of a
different color from the living wood outside of it, and this dead portion
becomes thicker year by year. It is called the Duramen, or "Heart-
wood," and it often contains medicinal or coloring matters. The outer
is called the Alburnum, or "Sap-wood." It is the duramen only which
yields the most of our colored cabinet lumbers.
Effects of Secondary Growth upon the Superficial Structure. — The
effect of secondary growth upon the structures external to the bast-
cylinder is extremely variable, according to the extent of such growth
and the relations of the phellogen and its structure and the individual
habit of the plant. It has been stated that the phellogen may develop
in any part of the cortex. It may now be stated that it may, and, in
fact, usually does, in the root develop in the bast-cylinder itself, so
that all the parts external to it, and even portions of itself, will belong
to the periderm, or in the rare case of Bork-casting by the root, will
be cast off.
Origin of the Branches of the Root. — In all the classes which yield our
medicinal roots, the branches start from the pericycle outside of a
xylem-bundle at the point h (Fig. 421), as it is first developing, and grows
through the surrounding tissue to and from the surface. If cross-
sections have been cut through a root so as to pass through its branches
also, the branches on the older part will appear as mature secondary
roots. Those lower down will be successively less developed, appearing
STRUCTURE OF STEM AS COXTRASTE /) WITH Til A T OF ROOT 145
at ItMifftli uj)()n the younger })()rti()n as not yet having made tlieir way
througli the overlying tissues to the surface. As the root first formed
is called the Primary, so its l)ranches are called Secondary. 'J'heir
structural develoi)ment is a rejx'tition of that of the ])rimary.
Continuity of Root-growth.- The continuity of growth in the root is
uniform — that is, there is no di\ision of it into joiuts or ])hytomers.
There are hence no regular distances at which it hranclus, and when
buds are produced ui)on it, as they are in rare cases, their points of
origin are not so regulated.
Structure of the Stem as Contrasted with that of the Root. — (The follow-
ing account of stem-structure refers only to the ordinary i)lants of the
flowering class. At its close a brief reference will be made to such others
as require attention for the pur])()ses of ])harmacognosy.)
The history of stem-devel()j)ment is best presented by contrasting it
with that of the root, which has already been given. The three elemen-
tary tissues, dermatogen, periblem, and plerom, are also found in the
young stem-structure. The epidermis and other tissues of the stem are
more variable than the corresj)onding tissues of the root, and the details
l)ertain for the most i)art to histology and to the special treatment of
species or groups.
The Epidermis. — The most im])ortant distinction between the ej)i-
dermis of root and stem may be mentioned as the i)resence in the latter
of stomata, to be studied in connection with the leaf. There is no
extra development from the dermatogen at the tij) corresi)onding to
the root-cap, nor of hairs similarly aggregated to those of the root,
although hairs of many forms abound upon the epidermis of the stem.
Stem-epidermis may consist of one or of several layers, and if the latter,
they may l)e dissimilar in varying degrees. Rarely it is i)ersistent,
being usually thrown off through the growth of the parts within it,
as has already been considered in the case of the root.
The Cortex. — The i)eril)lem of the stem develops structures in general
similar to thos(> of the root-pcM-ibU^n, the most imj^ortant distinction
being the ])r()(lucti(in of a (■hloro])hyll-hiyer. A ])riniai"y cortex, usually
somewhat thinner than that of the root of the same i)lant, is bounded
externally by a hypoderm and internally by an endoderm, and may
de\-elo]) tubes similar to tlio-e mentioned as fre(iiientl\- ])ei-taining to
the root-cortex, but, as in that case, no true \a>cular bundles. The
effects of growth within the ])rimary cortex of the root, leading to the
formation and casting off of bork, we h;t\e seen to be of rare occurrence.
In the case of the stem, howc\er, it is of \ cry general occurrence, so
10
146 GENERAL STRUCTURE OF ROOT AND STEM
that the entire account which has been given of the development and
disposition of periderm and phelloderm may be appKed with special
force in the case of the stem.
The Central Cylinder. — The principal differences between root-
structure and stem-structure are found in the de^'elopments from the
plerom. Although, with the single exception, among important medi-
cinal stems, of the male fern, there is but a single stele, in the form
of a central cylinder, yet the development of its structure is markedly
different from that of the root. Leaving out of consideration exceptions
which are unimportant in pharmacognosy, we find that two distinct
types, of structure characterize respectively the monocotyledons and the
dicotyledons and gymnosperms. The form characterizing the latter
two will be first considered.
TJie Primary Bundles. — Vascular bundles originate in the plerom in
the form of a circle, just as in the case of the root, the important differ-
ence being that each bundle consists, even in its primary state, of both
phloem and xylem, with a cambium between.
The Open Collateral Bundle. — The typical form is that which in the
root constitutes the secondary structure — namely, a bundle consisting
of xylem within and phloem without the cambium arc, and this con-
stitutes what is known as the Open Collateral Bundle.
Secondary Growth. — Secondary growth here consists in the addition
by the cambium to each kind of tissue, and, in almost all cases, the
development of new intermediate bundles and new medullar}^ rays,
as has been described in the case of the root. The result is that the
general plan of structure attained is identical with that already recorded
as ultimately attained by the most highly developed woody roots.
There are, however, several differences which must be noticed.
The Medulla or Pith. — The most important is that the primary
xylem-bundles do not progress toward and meet one another at the
center, so that there is always left there a cylinder of the fundamental
tissue, constituting the ^Medulla or Pith, which is connected through
the primary medullary rays with the pericycle, or, after the disappear-
ance of that and of the endodermis, with the cortex.
The whole structure in transverse section may now be roughly com-
pared with the wheel of a wagon. The pith corresponds to the hub,
the primary medullary rays to the spokes, the spaces between the
spokes to the primary wood wedges, the felloe to the bast product,
except that the spokes should be seen extending through it, and the
tire to the periderm in its various forms of development.
DIRECTIONS OF SECTION I-SG FOR EXAMINATION 147
Variations in Structure.— Altliouj,^!) the details of tissue-arrangement
pertain to histology, yet the deviations from the above relative positions
of the phloem and xylem are of such very great importance in pharmac-
ognosy that they are here referred to. We may have (1) the Bieollateral
Bundle, in which a second fascicle of phloem is placed upon the inner
face of the xylem; (2) the peculiarities characterizing the monoco-
tyledons, which will be described later.
There are three ways in which the strncture of the root or stem may
be examined.
Directions of Sectioning for Examination. — 1. A Radial section is a
longitudinal section in a plane passing through the center.
2. A Tangential section is a longitudinal section in a ])lanc which
does not pass through the center.
\\. A Transverse section is one i)assing exactly at right angles to
the former two.
Appearance of the Radial Section. — The appearance presented by a
radial section through a perfectly developed woody stem possessing
open collateral btmdles may now be described as follows, enumerating
the structures upon either side from the center outward: (1) Pith;
(2) wood wedges, with medullary rays, the latter, if primarj^, communi-
cating with the pith at the center and outward with the cortex; if
secondary, extending outward like the primary, but no farther inward
than the limit of the ring in which it originates; (3) the cambium;
(4) the bast bundles, separated by their medullary rays; (5) the phello-
derm, phellogen, and periderm, the relations of which to one another
and to the bast, and the structure of which, cannot be specified, owing
to the extreme variation which they dis])lay in different stems. The
composition of the bork, if any, will also depend upon the point of
development of the phellogen and its form upon the form of the latter.
Appearance of the Transterse Section. — Upon a transverse section,
the same structures as above recorded will appear, but instead of being
in the form of thin strips upon either side of the center, they will be in
the form of concentric rings around it. Thus the center is seen occupied
by a circle of pith, outside of which is a zone of xylem or wood tissue,
separated by longer or shorter medullary ra\s into its primary and
younger wood bundles. Outside of the first ainnial ring is where the
intermediate or secondary bundles make their first appearance. The
secondary medullary rays (Fig. 42)^, a) will be found not to extend
inward beyond the production of tissue of that year. Instead of appear-
ing as blades, as they did in the radial section (Fig. 42;>, b), the medullary
148
GENERAL STRUCTURE OF ROOT AND STEM
rays now appear as narrow lines. That is, we now see the edges of the
blades whose sides were before seen. Passing outward beyond the
last of the annual rings, which successively exhibit a greater number of
wood-bundles and medullary rays, we reach the cambium-ring. Outside
of this we find the phloem or bast bundles sejjarated by medullary rays
continuous with those of the wood cylinder, and still outside of this the
periderm.
Fig. 423. Diagram illustrating section of woody portion of dicotyledonous stem: a, edges of medul-
lary rays as seen in transverse section; 6, sides of same as seen in radial section; c, ends as they would
appear in tangential section.
Appearance of the Tangential Section. — The appearance of a tangen-
tial section will depend, of course, upon the tissues through which it
passes. If it cuts the medullary rays these will appear neither as the
broad sides, as at h, nor the edges of blades, as at a, but as transverse
sections of them, as at c. If the ray consists of but one row of cells in
width, then such a row will be exhibited upon the tangential section, its
vertical height varying from a very few to quite a large number of cells.
If, upon the other hand, it possess a lateral breadth of several thick-
nesses of cells, of 5 in our figure, this condition will exist only at its
middle portion. At its upper and lower limits it will ordinarily be
reduced to the thickness of a single cell, so that the tangential aspect
of a medullary ray is almost always that of an ellipse, broad or narrow,
according to the numl)er of rows of cells of which it consists, in contrast
with the extent of its upward and downward extension.
STRUCTURE OF THE MOXOCOTYLEDOXOUS STEM 119
Til sonic stems the ])illi oi' incdull.-i (lis;ii)|)c;irs more or less eom-
])Ietely after a time, lea\in<j; a eyliiidrieal liollow cavity. This may he
eoiitiiiiious throii,y;h the nodes or sejjarated at those i)oiiits hy transverse
partitions.
Structure of the Monocotyledonous Stem. In monoeolyledons (Fij;.
4lM) \\(> ha\-e the Closed hnndle, in which the one element surrounds
and encloses the other. In all medicinal monocotyledonous stems
possessing such hundles, it is the xylem which encloses the phloem. If
the two cylinders thus formed have a common center, which form is
not very common, it is called a Concentric hnndle. It is clear that in
the last two forms a caml)inm cylinder, such as distinguishes the stele,
possessing the form i)revi()usly considered, cannot be formed. In such
Fig. 424. Transverse section of monocotyledonous stem: a, closed hundles scattered through paren-
chyma; 6, nucleus sheath, or cndodermis.
plants indefinite growth in thickness of the hundles ohviously cannot
occur, and the same is true of the entire stele, unless new hundles shall
develo]) in it. Usually this does not occur, hut if the ui)i)er portion of
the plant shall l)ranch and continue to extend its leafy surface, meristem
tissue will then form toward the outer i)ortion of the stele, and from
this new hundles will successively arise, so that the thickness of the
trunk will kee]) ])aee with the extension of the crown, notwithstanding
that the individual hundles do not increase in thickness after the com-
pletion of their primary structure. In stems i)ossessing this form of
hundles the latter (Fig. 424, a) are found more or less scattered through
the fundamental or medullary tissue, though there is commonly more
or less of a concentration of them in some one region, usually toward
the i)eriphery of the stele.
150 GENERAL STRUCTURE OF ROOT AND STEM
The Nucleus-.^ heath. — The eiulodcnnis of such })hints is commonly
known as a Xucleus-sheath (6).
Polystelar Stems. — Finally, we note that in many plants, represented
among drugs by the ferns, the stem possesses a number, usually definite
for the species, of vascular bundles, or groups of them, each invested by
its own endodermis, each being thus a stele. Such stems are, therefore,
called Polystelar. In such plants no epidermis is developed, the
hypoderm, developed from the periblem, being superficial.
The Bark. — Its Nature. — The Bark is everything external to the
cambium. It has been proposed to remove the word "bark" from
common language, or to ignore its fixed common meaning, and to
convert it into a technical name for the bork. Experience with English-
speaking people leaves no hope that thej^ will consent to give up a word
employed so widelj' and in such important ways, and its technical use
can apparently result only in the introduction of a confusion, which is
more wisely avoided by the coining of some new' name, if that of bork
is seriously objectionable, which does not appear to be the case.
Importance of the Bark in Pharmacognosy. — Viewed from the stand-
point of pharmacognosy, the bark, especially when detached from the
remainder of the root or stem, is one of the most important portions
of the plant. As has been seen, it is not a simple structure, but develops
in part from the plerom, as well as from the periblem, and bears fre-
quently, although this is not true of any detached medicinal bark, the
epidermis as well.
Layers of the Bark. — In practice, the bark is commonly differentiated
into three layers — the Endophloeum, that portion resulting from the
plerom; the Mesophloeum, which is either the primary cortex, or the
products of a phellogen developing external to the endophloeum, or
both when they exist together; and the Exophloeum, consisting of a
primary periderm. If, as is not the case in any medicinal bark, the
epidermis persist, it will form the exophloeum. It has already been
made clear that a bark can come to want successively its exophloeum,
mesophloeum, and even the outer part of its endophloeum, as is seen in
some Cinchona bark, from old trees.
The study of barks includes a close examination of the cellular
elements, as a preparation for which histological work is absolutely
necessary. Examination of its gross characters involves, as the more
important features, its extreme and average thickness, its manifest
layers, as seen with a lens on transverse or radial section, their relative
thickness, color, markings, consistency as shown by fracture, their
THE BARK
151
separability from one another, that is, into
laminae, together with the snrfac-e char-
acters of the latter, the external color and
level markin<;s, the jiresence and natnre of
parasites, and the color and inequalities of
the iinicr surface.
The Laminae- The laminae do not
dcixMid entirely upon diifcrent tissue com-
position. The same tissue, produced at
diiVcrent times, may ])resent differences
sufficient to result in different degrees of
cohesion, as well as markedly different
color, at different depths, so that separation
may readily occur, or they may readily l)e
distinguished in sections.
Section-markings. — Groups or radial or
tangential rows of tissue-elements, differing
from those adjoining, frequently produce
gross markings on the section-surface.
Fracture. — The fracture of barks or of
their individual layers is denominated in
general as being brittle or tough, ^'ari()us
modifications are soft, earthy, granular,
horny, waxy, fibrous, splintery, or flexible.
A bark may be flexible hi one direction and
not in another.
The Outer Surface. — The outer surface is
described in general as being harsh, rough,
downy, smooth or shiny, and its luster may
be waxv, ^•itrcons, and so on. Some of the
Fig. 425. Section of young Calisaya bark, showing wrinkling
in drying. 42G. Section of old Succirubra bark, showing
ridging.
Fig. 127. (^lili of mature Cali-
saya bark, sliowing transverse and
longitudinal fissures.
152 GENERAL STRUCTURE OF ROOT AND STEM
elements causing roii^-hiiess may require mieros('()])ical examination
for their demonstration, while others are otherwise manifest.
Ridges and Furrows. — Care must be taken to distinguish between
ridging and furrowing of different kinds. One kind is caused by a
longitudinal wrinkling in drying, as in young Calisoya (Fig. 425).
Another is owing to transverse (as in old Calisaya) or longitudinal (in
the same) fissuring (Fig. 427). Another is caused by the elevation of
corky ridges, or rows of corky warts, which may or may not become
confluent in variable degree (as in Succiruhra, Fig. 426). Fissures may
characteristically open in the crest of a ridge or in the otherwise un-
changed siu-face.
Color-markings. — Most color-variegations are due to lichens or
other parasites, and those due to lenticels are also very common. A
single color or shade of color of the inner surface is rarely characteristic,
as it changes very greatly with age in keeping; but a carefully arranged
series of them may be made diagnostic in many cases.
The Inner Surface. — The important characteristics of the inner
surface depend upon the projecting bast-bundles caused by contracting
medullary rays. Very rarely, indeed, is the surface so free from these
inequalities that it can be properly described as smooth. The slightest
manifestation of the bundles gives the Striate condition. The striae
must be examined as to length, straightness, direction as contrasted
with the axis of the bark, apparent interconnection at the end, width,
elevation, and sharpness, with the complementary characters of the
intervening furrows or pits. Some barks show a tendency to separate
into laminae which run obliquely out upon the inner face, appearing
there as partially separated tongue-shaped splinters.
No attempt has ever yet been made to classify the markings of the
inner surfaces of dried barks, and to provide a terminology for them.
In the absence of this important treatment, it is difficult to teach the
details of the subject, except by the use of the actual objects.
(' II A PTK K X 1 \'
VERTICAL AND LATERAL EXTENSIONS AND APPENDAGES
OF THE STEM
Origin of Branches and Leaves. — Examining a radial section of the
tip of the stem (Fig. 4) we find, in addition to the structures already
considered as helonging ])rimarily to itself, protuberances, consisting
of masses of meristem tissue belonging to the periblem and the derma-
togen. Shortly, each of these tissue-masses assumes, in a general way,
the condition of the primary growing point of the main stem. Some
of them will develop into leaves, the structure of which will be con-
sidered farther on, others into branches, which latter j)r()cess is a mere
repetition of that already considered in relation to the })rimary stem.
In either case, the vascular bundles exhibit a connection, variable in its
details, with those of the stem from which it develops.
Arrangement of the Leaves and Branches. — The normal method is for
a l)ranch and leaf to develop together, the former in the axil of the
latter, as already recorded. If two or more leaves, with their branches,
develop at the same node, it results in the opposite or verticillate
arrangement. If but one, then, of those developing at different levels,
each is successi\ely separated from the former by a uniform portion of
the stem circumference, so that a spiral arrangement results. This
s])iral will be considered when we come to the study of the leaf.
Growth of the Internodes. The ])oiiit at which one or more leaves
de\elop has alread\' been defined as the node, and the poi'tion of stem
intervening between two nodes as the internode. At first tlu- internodes
are so short as to be scarcely perceptible, but they continue to grow
in all j)arts until a length more or less definite for the sjiecies is attained,
so that leaves and branches become separated by imiform vertical as
well as circumferential spaces. This brings us to another great distinc-
tion between tli(> stem and the root, in which latter we lia\-e found a
contiiuions and uniform longitudinal de\elopnient.
Axils in which Buds do not Develop. The rule that a branch de\eloi)s
in each leaf-axil is habitually (lc|)arted from in the leaf-representatives
constituting the flower, and accidentally in sonic other cases. Its
failure to devel()|) may be tem]jorary, although oftiMi \-cr\ long con-
tinued, or it may be permanent.
154 EXTENSIONS AND APPENDAGES OF THE STEM
Occasional Failure of the Leaf to Develop. — U])()n the other hand, the
subtending leaf may fail, accidentally, or in a few cases habitually, to
develop, so that the branch does not show its axillary nature.
Abnormal Position of Branches. — Finally, we note that a branch may
accidentally, or in some cases habitually, develop from some other
point than the leaf-axil, or two or more may develop, at least partially,
from one axil, either side by side or in a vertical row.
Not only may a lateral branch thus fail to develop, but the apical
extension of the growing point may fail, accidentally or habitually,
the growth being continued by means of one or more branches only.
Sympodial and Monopodial Stems. — When this method of growth is
characteristic, the new branch taking the place of the suppressed stem
which produced it, at each successive node, so that the stem becomes
composed of a succession of one-jointed branches, the stem is called
Sympodial, as contrasted with the term Monopodial, for the ordinary
form, in which the apical growth, as well as that of the branches, is
continued from joint to joint.
The natural result of such a series of branchings would be to produce
an angular divergence of the axis at each joint, as the branch projects
more or less laterally from its support. This, however, is usually not
the case. In many plants the new branch takes the erect position of
that which it has replaced, preserving the rectitude of the axis, and so
tending to obscure the sympodial nature of its growth. In such cases,
we must search for other indications of its nature. This subject will be
understood upon reference to the accompanying diagrams (Figs. 428
to 430), in which a in each case represents the apical extension, b the
leaf, c the axillary branch. It is seen that the positions of the three,
with relation to each other, are the same in every case, the axillary
branch being between the other two, no matter what changes in their
directions may occur. In Fig. 429 the apical phytomer has been
forced a little to one side, while in Fig. 430 it has become perfectly
horizontal, the branch substituting it in the erect position. It is clear
that in the last case, c might easily be mistaken for the main stem,
a for a branch. If this view is taken, however, we are at once met by
the difficulty that the supposed branch has no leaf at its base, that is,
it is not axillary, while the leaf, b, has no branch in its axil. Both these
difficulties entirely disappear when we regard the body between the
other two as the branch.
A mistake becomes even more easy when one of the structures
becomes modified into some unusual form. Thus, in Fig. 431, the
SYMPODIAL AND MONOPODIAL STE.\fS
155
terminal pliytonicr has become converted into a tendril (a). This
tendril must be a modified main stem, a modified l)ranch, or a modified
leaf, and the decision is perfectly easy when we intjuire as to its relation
to tlie axil. In Fig. 432, where the apical j)ortion has become converted
into an inflorescence, followed by a cluster of grapes, the determination
is the same.
In all these ilhistrations but one phytonier witli its ])r()(hicts is
displayed. By viewing a series of them, we are a})le to determine a
number of distinct forms of the sympodial stem, depending upon the
order of its branching. In Fig. 433 the branches are borne alternately
upon the two sides, and directed alternately to right and left, giving
fffl*.1
Figures illustrating sympodial growth: Fig. 428. a, superposed phytonier; I, leaf; c, axillary
phytomer or branch. 429. o, turned aside; b, assuming its place. 430. The change complete, the
superposed phytomer become lateral, standing opposite the leaf. 431. (The grape) same positions as
in 430: a, metamorphosed into a tendril. 432. a, converted into an inflorescence. 433. Alternating
sympodial growth. 434. Unilateral sympodial growth. 435. Bifurcating sympodial growth.
a flexuous appearance to the sympodium; but it must not be forgotten
that they may grow quite erect, the leaves alternating regularly upon
the two sides and the stem appearing monopodial. No axillary branches
will, however, be found. In Fig. 434 the branches develop successively
upon the same side. In this case, also, the fully developed portion of
the stem is straight and api)ears monopodial, exce])t that the leaves
are all upon one side (secmul), but the ])eculiar direction taken by the
undeveloped portion toward the tip indicates its true nature, as well
as the absence of axillary branches. Fig. 435 represents a sympodial
stem on which the branches are borne in ])airs, the obvious result being
a double symmetry, each branch successively ending in a pair of
156
EXTENSIONS AND APPENDAGES OF THE STEM
branches. This gives us the forked or Bifurcating form of sym])0(linm,
often called (Hchotomous, though this term refers strictly to one in
which forking is caused by the vertical division of a terminal cell.
Superficial Appendages to Stems. — Besides modified or unmodified
leaves or branches, stems may develop various other ai)i)endages.
When these are merely superficial, they are called Trichomes. The
characters of trichomes upon stems or leaves, particularly the latter,
are of the utmost importance in diagnosis. Their study, however,
save as to the surface characters which they collectively produce,
pertains to histology. The gross surface character so produced will
be taken up in connection with the leaf.
Fig. 430. Aculeate stem of Chadaea. a, hooked prickles.
Emergences or Outgrowths. — When ai)pendages are of deeper origin
they are called Outgrowths or Emergences. These may contain vascular
tissue, connected with that of the stem. Outgrowths are, for the most
l)art, in the form of spines, hooks (Fig. 436, a), warts, suckers (Ing. 459,
a, in this illustration a modified stem), or grasping organs. Usually
organs of this kind are the results of modifications of other organs,
rather than outgrowths. Both trichomes and outgrowths may be
regularly or irregularly disposed.
DUDS 157
Roots from Stems. — Roots may develop from branches which are
subterranean or which rest upon the surface of the ground or are high
above it. Tlie hitter may descend and enter the ground, fix themselves
to a neighboring body for sustenance or support, or both, or extend
into the atmosphere. 'V\\v\ may c\cn turn and cntci- a (lisca>c(l (ir
decaying ])()rti()n of their own ])lant. They normally (h'xcloi) from the
nodet)nly, but may dcxclo]) from any other ])art or ('\('n fi-om h'a\es.
Buds. — An undeveloi)e(l stem or branch, or the i)artially developed
summit of one, is a Bud or Gemma. The bud may be in a process of
continuous development of its lower elements into mature phytoraers,
with the continuous ])roduction of a new growing point, or it may
pass into a resting state between successive seasons of growth. In
the latter case it undergoes special modifications (6 in Figs. 447, 448,
and 450). Its outer leaves become developed previous to the resting
stage, but not as foliage leaves. They become modified instead in
various directions as to form, proportions, relative position, apjjend-
ages, and exudations, to fulfil tlie office of protection as scales,
and they subsequently fall away, ne\cr devel()i)ing into foliage leaves.
When no such provision is made, the bud is commonly destroyed, with
more or less of the young stem tip near it, during the resting period.
Occasionally the bud is protected for a time by a special covering, formed
by the petiole of the subtending leaf. It is then called a Subpetiolar
Bud.
CHAPTER XV
CLASSIFICATION OF ROOTS AND STEMS
CLASSIFICATION OF ROOTS
Roots may be classified as to their duration, their order in time of
development, place or nature of origin, function, form, and consistency.
Duration of Roots. — As to duration, we have roots divided into two
great classes, although the terms designating them are in general applied
to the plant as a whole rather than to the root. Monocarpous plants
are those which die after producing one crop of fruit; Polycarpous,
those which produce successive crops. The former are Annual when
they live but a single season — as the rag- weed and the sunflower;
Biennial, when they devote the first season to the storing up in some
receptacle, such as a fleshy root or bud, a supply of nutriment, and
fruit and die in the second season. The term winter-annuals has been
applied to those which begin their life during the latter part of the first
season, fruiting early the next season, so that their combined life during
the two seasons is less than twelve months, as in the case of wheat and
rye. Such may, by being planted early in the season, finish their
existence during one season, as in the case of spring wheat. Those
monocarpous roots which devote a number of years to the preparation
for fruiting, as in case of the century plant, belong to the Perennials. •
All Polycarpous roots belong, of course, to the perennials.
Order of Development. — Primary and Secondary Roots. — As to their
order in time of development, the first root developing from the radical
is the primary. All subsequently developed, whether from root or
stem, are secondary, although those developing from secondary roots
are sometimes designated Tertiary and so on.
The Tap Root. — If the primary root continue its development so as
to constitute a branch-bearing axis, it is called a Main-root or Tap-root
(F'ig. 439). The ultimate behavior of the tap-root, when not of the
fleshy- thickened storage class, depends upon the development of the
leafy crown of the stem. The extent of root-growth and its development
will agree with that of the stem-crown. Two forms of stem-crown are
ORDER OF DEVELOPMENT
159
rcc'()f];nized, the one liaviiiji; its l)raiiclie.s and leaves so disposed as to
coiidiict the rain whieh falls upon them in toward and down the stem,
the other condnctinjj; it outward, so as to fall from the perijjhery. An
examination of the former elass of plants may be expeeted to diselose
a ta])-r()()t which maintains a \ertical downward direction, its branching
not hein^' wide. TJiose of the second class will generally he found to
ha\c their tajj-roots (piickly dividing u]) into innncrous horizontal
branches which bear the greater part of their small absorbing rootlets
around the perii)hery, just where they will catch the droppings from the
peri])hery of the leafy crown.
Fig. 437. Tubercles of Jalap. 438. Death of first portion of stem, it.s subsequent growth maintained
by cluster of secondary roots. 439. Tap-root, with branches, of .4 TO6ro.sia, 440. Underground portion
of potato plant: a, tubers; h, rhizomes, the roots seen intermingled. 441. A napiform fleshy root.
442. Fusiform. 443. Conical.
The "Multiple Primary Root.'' — If the primary root of a very young
plant divide at once into a number of approximately equal branches,
it constitutes the so-called ]\Iultiple Primary Hoot. This term has,
however, been applied to a number of root-dusters of similar appear-
ance, but of very dissimilar origin. In some cases the primary root
continues its vertical growth but does not increase in thickness to any
a])preciable extent. A number of similar roots then develoj) near its
l)oiiit of origin, so that a fascicle of similar I'oots at length results, as in
the onion. In other eases a prostrate stem takes root from one of its
nodes, the j)()rtion below this point (Fig. 438, a), with the original roots.
160 CLASSIFICATION OF ROOTS AND STEMS
perishing. To the ckister of roots thus resulting, although they are
really secondary, the term "multiple primary" has also been applied.
A true multiple primary root is of rare occurrence and does not exist
among drugs.
Adventitious Roots.— AW roots which are not primary, or branches
thereof, and all branches of roots which are not de\'eloped in regular
order of succession, are called Adventitious.
Place and Nature of Origin. — Subterranean and Aerial Roots. — As to
their place and nature of origin, roots are Subterranean when they
originate from points underground, whether from root or stem, and
Aerial when they originate from points above the surface, whether from
root or stem. A root may originate from an aerial point and afterward
fix itself in the earth, as the Brace-roots of maize.
Fascicled Roots. — A number of approximately equal and similar
roots occurring in a cluster, especially if they be fleshy-thickened, are
denominated Fascicled.
Fibrous Roots. — Roots existing in the form of a mass of thin, fiber-
like, approximately equal and similar elements are called Fibrous
(Fig. 446).
Functions of Roots. — As to their functions, roots are known as Absorb-
ing, Fixing, and Storage roots. A root of one kind may give origin to a
branch of a different kind.
Haustoria. — Absorbing roots of parasitical plants are frequently
greatly modified in structure to form Haustoria.
Rhizoids. — Fixing roots are usually designated as Rhizoids.
Storage Roots are usually much enlarged and possess a fleshy con-
sistency and characteristic forms (Figs. 441 to 443).
Tubercles. — When only a limited portion of a root is fleshy-thickened,
so as superficially to resemble a tuber, it is called a Tubercle, as the
Jalap (Fig. 437). Care should be taken not to confuse this technical
meaning of the term with its common use as designating a small tuber.
Forms of Roots. — As to their form, roots are simple, when they do not
branch, or Branched, Cylindrical, Terete (which includes the cylindrical
and that form which differs only in that it tapers), Xapiform, when
taking the form of a short, broad turnip (Fig. 441), Fusiform when
spindle-shaped, as some radishes (Fig. 442), Conical or Cone-shaped
(Fig. 443), Capillary when very thin, long and 'hair-like.
Consistency of Roots. — Woody and Fleshy Roots. — As to consistency,
they are denominated as Woody and Fleshy. By "fleshy" or "non-
woody" we do not mean that wood tissue is entirely lacking, but rather
nruMios 101
tliat the })r()i)()rti{)ii of the (rllulnr, paroiidiymatic, or fiesliy elements
is so mueh <]jreater than that of the woody that a woody eharaeter is not
apparent. In practical pharmacognosy, where dried roots are mostly
observed, a number of other terms for consistency, as in the case of the
hark, come into use.
CLASSIFICATION OF STEMS
Stems may he chissified as to duration, order of d('\ cloiJinciit in time,
position, and nature of origin, mode of extension, direction of ii;rowth
and nature of sup])ort, modification of form or function, and consistence.
Duration. — As to duration, they are, like roots, Annual, Biemiial, and
Perennial.
Ilrrhs. — Annual stems are those which die at the close of the season.
They may or may not i)ertain to annual roots. Plants possessing them
are called Herbs. Herbs are therefore either Annual, Biennial, or Per-
ennial, in accordance with the character of the root, but their stems
are always annual. The definition of an herb is a plant, the aerial
portion of which dies at the season's close. The stem of an herb is
denominated Herbaceous.
Biemiial Stems. — Biennial stems are those which are jjroduced,
usually underground like that of the potato (Fig. 440, b), during one
season, and perish after the production of their branches in the following
season. Occasionali\", howexcr, like the cabbage, a biemiial stem is
aerial.
Tubcn'. — Fleshy-thickened and biennial portions of niidcrgronnd
stems, such as the ])()t;ito, ai'c denominated Tubers (Fig. 410, (i). l''ig.
444 represents tiic undei-ground poi-tion of the ('iirciniKi, and well
displays the dill'erence between tubers and tubercles.
Bulbs. — Basal biennial portions of stems which are invested by more
or less fleshy-thickened storage-leaves are called Bulbs. J5ulbs will be
classified under the subject of buds.
Perennial Stems. — Perennial stems are those which Wvv and extend
their growth from year to year. They are Determinate when their
growth of the season is self-limited and closes with the production of a
sj)ecially i)repared Winter-bud, which protects the growing point for
continued growth tlie next season; Indeterminate, when no such bud
is formed, growth contimiing until the aj)ical portion is destroyed by
an incl(Mnent season. In the latter class we have the anomaly of a
])ereiiiiial stem with an annual ti[).
11
162
CLASSIFICATION OF ROOTS AND STEMS
Order of Development. — Primary and Secondary Stems. — As to their
order of fle\elopment in time, stems are Primary, Secondary, and so
on, terms which are self-explanatory.
Place and Nature of Origin, — Aerial and Subterranean Stems. — As to
their j)()sition and nature. of origin, stems are Aerial or Subterranean,
which terms are also self-explanatory. A secondary stem assuming an
erect position from the base of the primary, like those of the Indian
corn, is a Sucker. Such an one arising from a rhizome at a considerable
distance from the original erect stem, as in the blackberry, is called a
Stolon. A short secondary stem developing from the base of the primary
is called an Offset. An elongated, slender one, lying prostrate and
rooting at some of its joints, is called a Runner (Fig. 445).
Fig. 444. Tubers of Curcuma.
44S.
445. Runner of strawberry plant,
scaly rhizome of Gesneria.
446. Fibrous roots attached to
The Rhizome. — An underground stem, fleshy-thickened at least during
the first year, so as to serve as a storage receptacle, and giving origin
to an aerial summit or branch, is a Rhizome (Figs. 447 to 452).
Distinctions betiveen the Rhizome and the Root. — A rhizome is very
frequently mistaken for a root, but the differences, both internal and
external, are well-marked. The internodes of the rhizome are com-
monly quite as uniform in length as those of the aerial stem. The nodes
are usually conspicuous. Leaves exist upon them, commonly in the
form of scales. Occasionally these scales are numerous and well formed
(Fig. 446), but usually they are rather obscure, as in the potato, where
they are mere semicircular or crescent-shaped ridges about the eyes.
In the axils of the scales, buds are usually to be distinguished. These are
the so-called "eyes" of the potato, and their develoi)ment into branches
is a familiar phenomenon. Internally, the structure of the rhizome is
in general that of the stem, though fleshy tissue predominates.
The growth and duration of a rhizome may be indefinite, like those of
stems, as in the case of the rhizome of Podophyllum (Fig. 449), or they
may be restricted to one or to a definite number of }ears, after which the
PLACE AND NATURE OF nUKlIN
163
oldest existing; ])liyt()nu'r ])erislios each year as a suceessi^■e a])ical one
is formed (Fij;. 450, h).
Forms of Rhizomes. — Rhizomes are so inimeroiis and important in
pharmacy that their characters call for special attention. They are
classed as short or elongated, the former term referring to those
4S2.
Forms of rhizomes: Fig. 447. Convallariti, with :iiiiiular roots: «, terminal l)ii<l. 448. Cimicifiii/n,
its cup-shaped stcni-scars much elevated. 449. Podophyllum, its intcrnodes elongated. 450. Poly-
poria/UOT, its cup-shaped scars depressed. 451. /n's, its roots aggregated at one end. 452. Acorus, with
V-shaped leaf-soars.
the extreme length or shortness of which fall within certain fairly
defined and restricted limits; the latter, those which cither j^ossess an
indefinite extension, or the definite length of which is a great many
times their thickness. Terms indicati\e of their form and consistency
do not differ materially from those a])i)lied to other stems and to roots.
They are almost always sympodial. They are very subject to flatten-
164 CLASSIFICATION OF ROOTS AND STEMS
ing, the flattened surfaces usually looking upward and downward. The
presence or absence of branches is always characteristic. The manner
in which the roots take their origin is c(|ually so. These may form a
circle (Fig. 447) or be restricted to the under surface (Fig. 449). The
number of roots developing from a node is usually fairly characteristic.
So is the persistency or brittleness of these, and the characters of the
stumps or scars which they leave, as well as their form, which is very
often triangular or quadrangular in section. Their structure, as observed
either with the lens or with the microscope, is characteristic and of
diagnostic value. Sometimes the roots are not only restricted to a
certain portion of the node, but in the case of short rhizomes are re-
stricted to a definite portion of the latter (Fig. 451). The relative length
of the internodes of a rhizome, as compared with its diameter or thick-
ness, calls for close attention, and so does the absolute or measured
length. The relations of the erect portions to the horizontal, and the
stumps or scars left by the former upon their death or separation, con-
stitute one of their most important diagnostic characteristics. Com-
monly, disarticulation occurs, with the production of a cup-shaped scar.
This scar will be characteristic as to whether it form a depression in the
general surface (Fig. 450) or be elevated upon a base (Fig. 448), as will
the length of the latter, the form and depth of the scar, and the char-
acter of its edge. The size of the scar, that is, its lateral breadth as
compared with the thickness of the internode, is also noteworthy.
Leaf scars, or leaf remains, upon rhizomes call for the same examination
as do the stem scars. They may surround the entire rhizome, in which
case they are designated Annular, or they may be confined to the upper
surface. If the latter, the scar may be of characteristic form, as linear,
elliptical, circular, cordate, crescent-shaped, or ^"-shaped (Fig. 452, a).
Finally, we note that annular or longitudinal folds, thickenings, wrinkles,
or constrictions are characteristic of certain rhizomes as well as of roots,
particularly in the dried state.
Mode of Extension. — Simple and Branched Stems. — As to their mode of
extension, stems may be Simple or Branched. A stem denominated as
simple is not necessarily entirely destitute of branches, as floral branches
or small branches near the summit are permitted. It has already
been shown that stems may develop monopodially or sympodially.
The stem of a tree which continues, except in case of accident, to develop
monopodially, as the Fir, is called Excurrent. One which after a time
loses its main stem in a number of branches, as for instance the elm, is
Deliquescent.
MODIFICATION OF FORM OR FUNCTION 1G5
Acauh'scent Plants. — The term Acaiileseent, wliile strictly meaning
stemless, can, of course have no such ai^phcation, as all fiowering plants
possess a stem, even before germination occurs. The term is applied
to those plants whose stems arc so short as not to become con-
si)icu()us.
The Crou'ii. — The stem of sudi a plant is called a ("rowii. The term
crown is also appUeil to the branching or leafy portion of any stem.
Trees, Shrubs, and Vudcrshruhs. — A plant possessing a woody and
erect stem rising singly to the height of fifteen (according to some
authorities, twelve) feet or more is denominated a Tree, or Arborescent
plant, although the precise application of such a term is impossible.
A perennial woody stem which has not these characters is called a
Shrub or a Fruticose stem. Very small shrubs appearing on causal
insi)cction as herbs are called Undershrubs or Suffruticose plants.
Direction of Growth and Nature of Support. — As to the direction of their
growth and the nature of their supjjort, stems may be Erect, in which
case they are erect through their entire length; Ascending, in which case
the base for a greater or less distance rests upon the ground, the terminal
portion becoming erect; Horizontal, in which case they are considered
as having no other support than the parent stem, from which they
extend at a right angle; Drooping, in which case they are first hori-
zontal, the outer portion becoming pendant; Pendant, or "Weeping,"
when they are pendulous from their point of origin or almost therefrom;
Decumbent, when at first erect or supported by the i)arent, the outer
l)()rtion dechned so far as to rest upon the ground; Reclining, when
resting ui)on some means of sui)i)ort elevated above the earth, as over
the t()i)s or branches of other i)lants; ProcnmlxMit, when resting at full
length upon the ground witlioiit rooting at the joints; Repent, or
"Creeping," when ])rostr;itf and rooting at the joints (Fig. 445);
Twining, when sup])orting themselves by the twining of the stem itself
around a support; Climbing, when elevating and sui)porting them-
selves by other methods than a twining habit, the principal forms being
the Cirrhiferous, when climbing by tendrils (Fig. 4;-51), and Aculeate,
when cliinbiiig i)y hooks (Fig. 4;]()).
Modification of Form or Function. — Mixli/ird Sfews. — As to modifi-
cation of form or function, stems arc snbj(>ct to a somewhat elaborate
classification.
They may be modified for the ])uri)osc of defence, that is into thorns
or spines (Fig. l.").'i), altliongli not all thorns or spines arc transformed
branches. Some branches of this foi'ni remain so permani-ntly, while
IGG
CLASSIFICATION OF ROOTS AND STEMS
others become foliaceous later and de\'elop into branches of the ordinary
form (Fig. 454).
For the purpose of cHmbing, they may become cirrhose, that is,
converted into Tendrils. The tendril may consist of the apex of the
^6.
Illustrating modified stems: Fig. 453. Branch converted into thorn. 4.54. The same becoming leafy.
455. Branch of Strychnos, becoming a tendril. 456. Stem of Lemma, modified like a leaf. 457.
Branches of a species of Asparagus, modified as leaves. 458. Condensed stems of Opuntia. 459.
Branches of Ampelopsis metamorphosed into disks. 460. Branches of Phyllanthus, modified like
leaves, but flower-bearing.
primary stem (Fig. 431), or one of the branches may become the tendril,
as in Strychnos (Fig. 455). In the latter case the tendril will stand in
the axil between leaf and stem; in the former it will stand upon the
opposite side of the stem from the leaf, for reasons already explained.
A stem may instead become converted into a sucking disk, as in the
MODIFICATION OF FORM OR FVSCTION 167
case of Ami)eloi>sis (Fig. 459, a). In this case the tip of tlie branch or
stem becomes flattened and attaches itself very tightly to the supporting
surface; so tightly, in fact, that a portion of stone or a splinter of wood
may be torn from its support before the disk can be made to separate
from it. Plants which grow in the water or in places subject to inunda-
tion may have portions of their stems inflated into bladdery forms to
insure a floating condition. Such structures are, however, more com-
monly of a leafy nature.
Cladoidia or Cladophylla.- — Stems may become modified for the j^er-
formance of the office of leaves. Such a stem is called a Cladoidium or
Cladophyllum (Figs. 457 and 400). For this purpose the whole stem
may become modified into a single leaf-like organ, as in the case of
certain aquatics, in which case it is known as a Frondose Stem (Fig.
456). Upon the other hand, separate portions of the stem or separate
branches thereof may become thus modified, as in the case of the so-
called "leaves" of the species of Asparagus cultivated as a decorative
plant under the name of Smilax (Fig. 457: a, leaf; 6, branch). Some-
times a stem or a joint of one, at the same time that it becomes modified
to perform the office of a leaf, performs the ordinary offices of a stem,
or important storage functions as well, as in the case of the Opnntia
(Fig. 458), and the Phyllanthus (Fig. 400). Such stems are called
Consolidated. Branches like those in Fig. 400, modified to perform
the leaf-function, are called PhyUocIadia.
]\Iany trees have been encountered by the author in troj)ical America,
the stems and branches of which are hollow (denominated fistulous),
afl'ording permanent homes to myriads of ants, which, deriving their
sui)port from the tree, are supposed to confer some compensatory
benefit upon it. They at least protect the tree against animal attacks,
being in all cases extremely savage and venomous.
Besides such specially modified forms, a number of ordinary forms
are characterized by the adjectives Terete, Cylindrical, Compressed,
Triangular, Quadrangular, Alate or Winged, Costate or Ribbed, Chan-
nelled, Striate, and so on. In this connection the terms a])plicable to
the superficial characters of barks already described, and those con-
nected with leaf-attachment, to be described farther on, should be
studied. In addition to the above-mentioned stem-forms, which admit
of ready classification, we have a large number of modifications to efi'ect
special purposes, which must be considered individually. As these
])ossess but a slight interest in relation to pharmacognosy, we refer the
interested student to more general works on botany.
168
CLASSIFICATION OF ROOTS AND STEMS
Storage Stems. — An important office of the stem is the storage of
nutriment. All stems perform this office to a greater or less extent,
but some are especially modified in form for the purpose. Of these, we
have already specially referred to rhizomes and tubers.
The Bulb. — It remains, then, only to consider the various forms of
the bud, including in this term all forms of the bulb. A bulb which,
like the onion (Fig. 462), has its fleshy-thickened leaves in the form
of broad sheathing organs, seen upon transverse section in the form
of concentric rings, is called Tunicated or Coated. Those like the lily
(Fig. 461), in which these leaves appear in the form of narrower pro-
jecting scales, are called Scaly. When in the axils of the scales we find
Fig. 461. Scaly bulb of Lilium. -iC^. Tunicated bulb of onion. 463. Corm of Gladiolus. 464.
Axillary bud-bulb of tiger lily. 465. Terminal head of bulbs of onion.
smaller or secondary bulbs or buds, as in the garlic, it is a Compound
bulb. When the texture of a bulb is so dense that its leaf-elements are
not conspicuous, it is designated as a Solid bulb. When it is still more
dense, as in the case of the Gladiolus (Fig. 463), so that the leaves are
not to be distinguished by ordinary methods, it is a Corm. In some
plants, the axillary bulbs, instead of occurring in the axils of the bulb-
leaves, occur higher up in the axils of the ordinary foliage-leaves, as in
the case of the tiger lily (Fig. 464). Their true nature as buds is in
this case conspicuously shown, and they are sometimes spoken of as
Bud-bulbs. In other related plants, similar bulbs are densely aggre-
gated in a terminal umbel looking like an inflorescence, as in some
species of onion (Fig. 465).
CLASSES OF BUDS 109
CLASSIFICATION OF BUDS
Buds ])ro])er admit of an elaborate elassifieation, whieh, although not
of such interest in pharmacognosy as to warrant its study here, is of
fundamental im})()rtance in systematic botany, and furnishes a key to
many ])roblems which are otherwise abstruse.
Vernation and Praefoliation. — The study of buds is called A'ernation,
and that of the arrangement of the leaves composing them Praefoliation.
In general, the arrangement of leaves in the bud admits of the use of
terms similar to those ai)plied to the parts of the perigone in a similar
state.
Classes of Buds. — Buds may be classified as to their structural form,
their position, and parts. A winter bud which protects itself by specially
developed scales is known as a Scaly bud; one which does not, a Naked
bud. A bud consisting only of leaves is a Leaf bud ; one only of a flower,
a Flower bud; one consisting of both, a INIixed bud. Solitary l)uds
occurring in the axil of the leaf and developing at the regular time are
called Normal buds. Any buds in addition to the normal bud, occurring
in the leaf axil, are called Supernumerary. They may be situated above
or at the side of the normal bud. The normal bud is sometimes situ-
ated a little above the actual axil, in which case it is called Supra-axillary.
All the buds here noted are denominated Lateral, in contradistinction
to the single terminal bud, but it is to be noted particularly that buds
lateral as to their origin may become terminal through the effects of
sym))()dial growth. Buds which dcNelop at other points than the aj)ex
or axil- as, for instance, fi'oin an internode, a leaf, or, rarely, even from
a root, as well as those of axillary origin, but developing out of their
regular order — are called Adventitious. The latter form of aihen-
titi(nis buds, when I'csulting from retarded dcNcloitnieiit, are know n as
Latent buds.
CHAPTER XVI
THE LEAF
Importance of Leaf-study. — To the pharmacognosist a thorough
knowledge of the leaf is a necessity. Of its cellular structure, little can
be learned without the aid of the compound microscope. Its gross
parts were briefly referred to in our opening chapter, and these must
now be studied in detail.
Development of the Leaf. — The varied forms of structure which leaves
present can best be understood by considering them as modifications of
an original or primary leaf and noting the changes in the latter which
have occurred to produce them. It is apparent that such a primary
leaf was a mere scale of small size, as indicated in Fig. 466. It then
appears that any modern foliage leaf must have resulted either from
the uniform growth and development of all the parts of such a scale, or
from the greater relative growth of some one or more of its parts. The
result of its luiiform growth would be a leaf of the same form, but larger,
its base sheathing the stem, as represented in Fig. 467. But leaves of this
exact character are rare, from which it would appear that modern leaves
generally represent unequal degrees of development of the different
parts of the original leaf. Their attentive examination shows that the
following parts of such a primary leaf have in different cases undergone
independent enlargement and development. In Fig. 468, the portion a,
cut off by the dotted line at the top, may represent the Apical region;
that at h the Central-basal; the strip a-h the axial; and the remaining
portions upon either side (c and d) the lateral. Let us assume first that
the enlargement is confined chiefly to the central-basal portion. The
base will then become converted into the form represented in Fig. 469,
without the enlargement of the other parts there shown, this leaf being
a mere sheath around the stem, bearing the original scale at its tip.
Leaves of this form are rather common upon undeveloped or partly
developed stems. They are called Leaf-sheaths, or often, for emphasis,
Naked Sheaths. The edges of such a sheath may cohere after passing
around the stem, giving us the Closed Sheath, as in the sedges {a, in Fig.
465 B), or they may remain free, giving us the Open Sheath of the
DEVELOPMENT OF THE LEAF
171
grasses {a, in Vv^. 4().5 A). Instead of passin^^ around the stem, tlie
edges may come together between the leaf and the stem, so as to produce
a hollow tube, as in the Sarracenia. Let it next be assumed that the
apical portion, as well as the central-basal, enlarges, with little enlarge-
ment of the axial or lateral portions. We shall then get a form in which
a Lamina, or Leaf-blade, is superposed directly upon a Leaf-sheath,
Such a leaf, expanded, would appear as in Fig. 470, if the blade were
46SA. 465 B. 4Y0. 47/
4r2
Figures illustrating the origin and development of the parts of the leaf: Fig. 465 .-1. The grass-leaf:
a, the open sheath; h, the ligulc. 4()o B. Tlie sedge-leaf: a, the closed sheath. 466. The primordial
leaf, a mere scale. 467. The same, as equally developed in all parts. 4GS. The same, divided into its
different regions: o, the apical portion; b, basal portion; c and d, lateral portions with axial portion
between. 469. The same, undeveloped except the basal portion, which becomes a sheath to surround
the stem. 470. The same, with the apical portion also developed to form a blade, the lateral and
axial portions undeveloped. 471. The same, with the lateral portions developed into stipules. 472.
The stipules with their inner margins connate between the blade and stem, their outer connate around
the stem, forming an upper sheath or ochrea. In 40.5 .1 they are connate only by their inner margins,
between blade and stem, forming the ligule. (Ailaptid from work of A. A. Tyler.)
but little developed, or it inight be deNcloped e(nially in botli ]iarts.
Both of these forms are fre(piently encountered. If now the hiteral
portions shall enlarge, the axial jjortioii not imich elongating, a lateral
appendage must result at the base ui)on eitiier side, as in Fig. 471.
These are the Stipules. If the stipules, insteatl of existing separately
in this way, shall incline together between the stem and the leaf, and
their inner edges cohere, it is clear that they must form a small blade
172 THE LEAF
standing out upon the face of the leaf at its base, as h in Fig. 465 A.
This is the Ligule. The free edges of the Hgule may now pass around the
stem, meeting and cohering upon the other side, thus forming a sheath
above the basal portion, or true sheath (Fig, 472). Such a sheath is
called an Ochrea. If, lastly, it be assumed that the axial portion a-h
(Fig. 468) undergo an elongation much greater in proportion than the
enlargement of the other parts, we shall ha\e developed a long narrow
division between the base and the lamina, as c in Fig. 3, which is the
Petiole. It is thus seen that the view here taken will account for the
origin of every part of the leaf. The few illustrations here shown refer
only to certain combinations in the development of the difi'erent parts.
As a matter of fact, such combinations found among existing leaves are
innumerable, and this variety is increased by the fact that the growth in
any one of these parts may be chiefly lateral or chiefly vertical, and
that it may be confined wholly or chiefly to some special portion of
the part. The student will, nevertheless, be able, by bearing in mind
the typical possibilities here considered, to determine the plan of struc-
ture of most leaves. This view will also make clear the statement in the
opening chapter in regard to the absence of the blade, petiole, or other
parts from certain leaves.
It is interesting to note here that there is ample evidence to prove
that the rudimentary or scale-like form of leaves existed upon the
earliest flowering plants, so it would appear that the parts of their
flowers were developed from such scale-leaves, rather than from the
highly developed leaves which we now know. Against this, we have
to consider that those floral parts were probably of correspondingly
simple development, and that, in the higher plants of today, they
have undergone a development which has kept i)ace with that of their
leaves.
As to what constitutes the tyjjical leaf, we are confronted by two
views. Structurally considered, it must be such a leaf as represented
by Fig. 467, but such leaves, as we now see them upon plants, do not
apparently so well perform all the functions of the leaf as those which,
like Fig. .'!, have developed the modern leaf-parts.
The Leaf-Surfaces. — Very rarely has the leaf a terete form and a
radial structure as seen in transverse section. Typically it is a flattened
body. One flattened surface, the Ventral, faces upw^ard or toward the
stem which bears it, and is ordinarily spoken of as the upper surface.
The under or outer surface is technically known as the lower or Dorsal.
By a partial twist in the petiole, the surfaces may become laterally
THE STIITLKS 17:i
placed, tlu' cduvs vcrticjil. In ;i IVw leaves, tlie surfaces are normally
in the latter i)<)siti()n. Between the (h)rsal and ventral surfaces, there
are usuall\- (hll'erenees sufficient to necessitate their description sepa-
rately. In such descrii)ti()ns, it is better to speak of the dorsal surface
as being underneath rather than "helow," as the latter term may
confuse it with the basal region.
Anatomical Elements of the Leaf. — It has been shown that the leaf
originates and develops as an extension of tlie peril)lem, covered by
that of the dermatogen, and that it develo])s a stele which becomes
continuous with that of the stem. In other words, its mode of develop-
ment is precisely like that of a stem-branch. We have in it, therefore,
all the elements which characterize primary stem-structure. The
connection of the leaf with the stem is usually by a s})ecially arranged
and constructed tissue, forming a distinct organ, the pulvinus, which
provides an articulation designed to afford a prompt and ready separa-
tion of the leaf at the conclusion of the performance of its function,
as well as for certain movements and changes of position during life.
Just as branches of the cauline stele pass into leaf and branch, so
do those from the foliar stele pass laterally into its expansions, and
secondary and tertiary ones successively pass from them. These
branches are \ery frequently joined at their distal ends to others (Fig.
525, o), as well as at their proximal ends to the parent system. Whether
such is or is not the case, the result of the branching is the production
of a framework or skeleton which forms a support to the parenchymatous
tissue which fills its meshes and co^•ers its surface, the latter being in
turn covered by the epidermis.
Except as to the general characters which follow under leaf-classi-
fication, it is im])ossible to ascertain the structure of the cortex and
epidermis of the leaf by ordinary methods, so that this subject is
relegated entirely to the (lei)artment of histology.
The Stipules. — Before ])roceeding to the study of the leaf-blade,
which specially concerns us, certain peculiarities of the stipules, and
of the petiole, may be considered. The original function of the stipules
was probably to afford a protective covering to the bud. While this
function still persists, it is doubtful if that of increasing the foliaceous
surface has not come to be of greater importance. We should, therefore,
expect them to develop tissues and forms resembling those of the leaf-
blade, and such is the case, making them subject to the same classifica-
tion and terminology in those directions as will be ai)plied to the leaf-
blade. They ha\'e, however, certain peculiarities of their own which
174
THE LEAF
here require attention. As to their presence or absence, leaves which
possess them are called Stipulate; those which do not, Exstipulate:
As they frequently fall with the expansion of the bud, there is great
danger that a stipulate plant may be mistaken for one which is not.
As to their duration, in relation to the leaf-bud and leaf, the terms
caducous, deciduous, persistent, and so on, are applied to them as to
the parts of the perigone.
It has been shown that the two stipules of a leaf may unite with
one another by either margin. They may also unite with either the
petiole or margin of the leaf -blade, or with the stem of the plant, in which
Fig. 473. Cordate leaf of Nymphaca, with the margins of the sinus connate at a. 474. Inter-
petiolar stipules of Diodia. 475. Stipulate compound leaf, with stipellate leaflets.
cases they are called Adnate. When leaves are opposite one another,
the two stipules between them may unite with one another by their
adjacent margins, forming the Interpetiolar Stipule (Fig. 474, a).
Especial importance attaches to this class of stipules, because of the
remarkable variation displayed in their subdivision and appendaging,
and the great value of their characters in generic classification in certain
families, especially in that highly medicinal one, the Rubiaceae.
In some cases, the stipules so closely resemble the foliage-leaves
that, together with the blade, they present the appearance of a group
of three leaves standing side by side. In the case of opposite leaves,
this sometimes makes an apparent whorl of six similar leaves, or,
DURATIOS AM) RI'JTKNTION UPOX TIIK I'LAST 175
tlirouiili the union of the adjacent stipules, of four. In sncli cases, the
k'a\cs \vhich are sti])ulcs can be distinguished from the others by their
faihu-o to develop axiHary buds. The stipule is frequently transformed
into one or more bristles, or even strong spines, and occasionally into
a tendril (Fig. o()r)).
A secondary stipule, borne at the base of one of the (li\isions of a
compound leaf, is called a StipeUa (Fig. 475, a).
The Petiole. — Leaves possessing the Petiole; are called I'etioled those
wanting it are called Sessile (Fig. 478). Occasionally the petiole is
present, but adnate to the stem of the plant, thus appearing wanting.
In other cases, while quite free from the plant-stem, more or less of
the base of the petiole will clasp it. Such a Clasping petiole must not
be mistaken for a leaf-sheath, which, as we have seen, is not a true
petiole at all, but the development of a different part of the primary
leaf.
When the margins of the petiole throughout are herbaceous and in
continuation with the blade, the petiole is said to be INIargined or
Winged.
When the margins of the ])etiole are less ])r()n()unced, ])ut yet present
anfl elevated, so as to form a groove upon its upper siu'face, the petiole
is called Channelled.
Other characters of the petiole, such as its triangular or semicircular
form in transverse section, its relati\-e stoutness, and the character of
its surface, need not be specially considered. Certain special modifica-
tions in the function of the petiole will be considered under modified
leaves.
The attachment of the i)eti()le to the leaf-blade is always really
marginal, though by the cohesion of liasal lobes (Fig. 47i), a) it is often
apparently intra-marginal or even central. Basal lobes may, ui)on the
other hand, be adnate along the petiole, or the same appearance may
be produced })y the gradual difi'erentiation of petiole into blade.
Petiolar Glands. — (ilands of various forms often appear upon some
part of the jx'tiole, and their appearance is characteristic and of diag-
nostic value, as in distinguishing the species of Pnniu.s and Cassid.
Duration and Retention upon the Plant. — As the duration of the leaf
and its retention upon the i)lant ha\e to do in part with the nature of
the petiole, it may be here considered. Lca\es are Annual, and the
])lants producing them deciduous, when their duration is tluough a
single season only, and Fvergreen, when they remain in their normal
and active condition into the succeeding season. Evergreen leaves
176
THE LEAF
may be either biennial, the onHnary form, or perenniah Persistent
leaves are those which remain upon the tree, but in a dead condition,
being usually forced off by the growth of the following season.
The Lamina. — Coming now to the consideration of the leaf-blade, we
note that it is to be studied, and its varieties classified, with regard to
its relation to its support, its texture, surface, form — this including the
general outline as well as special forms of apex and base — venation,
margin, division, and modification of form and function.
Relation of the Leaf-base to the Plant-stem. — When a i)etiole or a
lamina has grown fast for a portion of its length to the plant stem, it is
called Adnate (Fig. 477). One whose base is heart-shaped and surrounds
the plant stem, whether growing fast to it or not, is called Amplexicaul
47Z
Modifications of the leaf-base: Fig. 476. Connate-perfoliate (boneset). 477. Adnate to plant stem
{V erhascum) . 478. Sessile (Solidago). 479. Amplexicaul (^Asler Novae-Angliae). 480. Perfoliate
{Oakesia). 481. Margined {PlaiUago). 482. Continuous. 483. Intramarginal-peltate.
or Clasping (Fig. 479). When the basal lobes of a clasping leaf entirely
surround the stem and become connate upon the other side, so that the
Stem appears to be growing up through a perforation in the leaf, the
leaf is called Perfoliate (Fig. 480). When opposite leaves are connate
by their bases they are called Connate or Connate-perfoliate (Fig, 476).
When the bases of sheathing leaves clasp the stem in such a manner as
to present a V-shape in transverse section, and one is superposed upon
another in the same manner, they are called Equitant.
Relation of the Base to the Petiole. — As to the attachment of the blade
to the petiole, the leaf is Peltate when this insertion is intra-marginal
through the connation of the edges of basal lobes. A peltate leaf may
be Centrally (Fig. 473), or Eccentrically (Fig. 483) peltate. When the
petiole changes so gradually into the lamina that it is impossible to
SURFACE 177
say wliere one Ix^^ins aiul the other cinls, we say they arc Continuous
(Fis- 4S2)-
Texture. — As to their texture and consistency', the or(Hnai-y form of
leaf, in which it ])ossesses active chlorophyll tissue, is denominated
Ilerhaceous, in contradistinction to the Scarious or Scariose form, in
which it has a (hy and papery texture. Herbaceous leaves are ]\Iem-
l)ranacet)us in their ordinary form, that is, not excessively thickened,
Coriaceous when tough and leathery. Fleshy or Succulent when largely
parenchymatous, thickened, and juicy. A leaf which exhibits trans-
lucent dots when held against a strong light, due to the presence of
oil-glands, is called Pellucid-punctate.
Surface. — The surfaces of leaves may be classified in two ways: First,
as to the characteristics of the individual trichomes which they bear;
second, as to the general surface effects (Indumentum) which result from
the latter. The former method, although it cainiot be taken uj) in this
part of the work, is of very great importance in the characterization
of medicinal herbs and leaves, especially as it constitutes one of the
greatest aids to the identification of powders. The latter method can
only be studied with advantage by the actual examination of typical
specimens, it being almost impossible to characterize the different forms
by definition. A surface is Opaque when it is not shining or lustrous.
It is Glabrous when it does not possess any trichomes in such forms as
to detract from the smoothness of the surface. It is Glaucous when
covered with a waxy exudation, imparting to it a peculiar whitish
appearance ("bloom"), such as characterizes the surface of an ordinary
black grape. It is Scurfy when covered with more or less of an indumen-
tum in the form of granular or detached scaly masses. When the matter
of such masses is more thinly distributed, appearing in the form of a
powder rather than a scurf, the surface is called Pulverulent.
A Pubescent surface is a hairy surface which is not readily dis-
tinguished as pertaining to any one of the other specific classes.
If the hairs of a ])ubescent surface are very short and fine, so that
the consequent roughness is reduced to a minimum, the surface is
called Puberulent.
If a hairy indumentum is fine and of an ashy-gray color, the hairs not
arranged in any regular direction, the surface is Cinereous.
If the hairs all lie in one direction, are closely appressed, and ha\e a
shiny or silky luster, the surface is called Sericeous.
If this luster is intensified and of a strongly whitish color, whether
the trichomes be hairs or scales, the surface is denominated Argentcous.
12
178 THE LEAF
Such hairs as are cai)able of producing a sericeous surface are them-
selves denominated sericeous or silky, even though they be in insuffi-
cient numbers to impart this character to the general surface.
A surface tending toward the sericeous, but not sufficiently pro-
nounced, is called Canescent.
When there is a dense covering of more or less elongated and matted
hairs, the surface is called Tomentose.
When such a covering is thin, its hairs less elongated, it is called
Tomentellate.
Whene there is a covering of thinly distributed, elongated, moder-
ately soft hairs, which are not closely appressed, the surface is Pilose.
When hairs are similarly distributed, but are elongated and coarse,
the surface is Hirsute.
When similar coarse hairs are rather stiff, lie in one direction, some-
what appressed, and particularly when each develops from an elevated
base, the surface is Strigose.
A surface which possesses an indumentum of scales is called Lepidote.
A surface is called Papillose when it is minutely warty, or tuberculate,
due usually to glands underneath the siu-face.
Wlien the indumentum consists of hard, ele^'ated points, giving a
roughness to the surface, the latter is Scabrous.
When such elevations are more pronounced, unyielding, and sharp-
pointed, the surface is Hispid.
A surface which is roughened by the presence of numerous, closely-
set wrinkles is Rugose.
When a surface is made up of small, blister-like elevations consisting
of the arching interspaces between the veins, it is Bullate (Fig. 484).
The opposite surface, containing the cavities of the bullae, is called
Cancellate (Fig. 485).
When the hairy covering is chiefly confined to the margin, presenting
itself in the form of a fringe of hairs, the term Ciliate is applied (Fig.
475).
A surface which is marked by spots differing in color from the remain-
der of the surface is called Maculate. If spots of any kind be small
and dot-like, the term Punctate is applied.
Finally, it is to be noted whether the veins or ribs, and if so which
of them, are prominent upon both sides or either side, or whether, upon
the contrary, they are depressed (called Impressed) below the general
surface. At times a rib or vein will not be impressed, but will yet be
Channelled, and may appear impressed upon casual observation.
SURFACE.
179
By the outliiu' of tlic leaf, we refer to the general form of its margin,
wliether that he I'litire, or not. If not, then the j^eneral form of an
outHne is determined by connecting' the extreme points of its margin
with one another (Fig. 480, an ohovate onthne). It matters not, there-
fore, whether a leaf be entire, toothed, h)bed, or ])arted, or even if it be
entirely compoimd or decompound, its outline will l>e the same, pro-
vided a line connecting its extreme marginal points with one another
possess a given form. The forms of leaves on this basis may be divided
into three general classes — (a) those broadest at or about the middle,
(6) those broadest at some ])oint al)ove the middle, (c) those broadest
at some \nnnt below the middle.
Vc?^
fz%
'*>«
Fig. 4S4. A bullate upiicr 8urf;i(
, A caiu'olla
^
Of the first class, beginning with the narrowest, \\e have the Capillary
or I lair-like forms, the P^iliform or Thread-shaped (Fig. 491), the Acerose
or Needle-shaped (Fig. 492), as those of the pine, and the Linear or
Ribbon-shaped (Fig. 487), all of which are so elongated that they
present the appearance of being about of uniform width throughout.
A leaf similar to but shorter than the linear, in proportion to its
breadth, without regard to the character of its apex or base, is Oblong
(Fig. 488).
One of similar form, but Inning a length of not more than t^\i(•e or
thrice its breadth, and narrower than a circle, is ()\al (Figs. 489 and
490), a term which must not be confoniuied with Ovate.
If an oblong or an oval leaf i)ossess a regularly rounded outline into
and through the ai)ical and basal portions, it is called Elliptical. \Ve
have, therefore, two forms of the elliptical leaf, denominated respectively
Oblong-Ellii)tical (Fig. 488) and ()val-Ellii)tical (Fig. 489).
180
THE LEAF
A circular leaf (Fig. 493) is called Rotund or Orbicular.
Finally, we have the leaf which is broader than circular — that is, its
lateral diameter is greater than its vertical, and this is called Trans-
versely Elliptical.
497
Leaf outlines: Fig. 486. Obovate compound leaf of rose. 478. Linear leaf of I/ireon'a. 488. Oblong-
elliptical {Poterium). 489. Oval elliptical {Pyrola). 490. Imperfectly oval {Prunus). 491. Filiform
(Drosera). 492. Acerose (Pinus). 493. Rotund (Pyrola). 494. Ovate {ColUnsonia). 495. Reniform
(Asarum). 496. Lanceolate {Solidago). 497. Lancelinear (Salix).
Forms Broadest below the Middle.— Those which are broadest at some
point below the middle or above the middle should, in description,
besides being designated by the class-name of their form, have it
specified in some way as to about the portion at which the greatest
breadth occurs.
Beginning with the broadest ones, we have that which is broader than
long and with a heart-shaped base, called Reniform (Fig. 495).
One which possesses a length greater, but not more than two or three
times its breadth, is called Ovate (Fig. 494).
One of similar form, but its comparative length greater, is called
FORMS niiOADEST ABOVE THE MIDDLE
ISl
Lanceolate (Fig. 496). One wliich is ovate, but with the greatest
l)rea(ltli at the very base, the margins not or ])ut httle curved, so that
it is approximately triangular, is called ])clt()i(l (Fig. 498).
One still narrower, but of similar form, Ijcaring the same relation to
the lance()l;it(> wliich the deltoid does to the ovate, is called Subulate,
or awl-shai)ed (Fig. 499).
An ovate or oval leaf whose outline, instead of being regularly curxed,
is made uj) of four comi)aratively straight hues is called Traj)e/.oidal or
Angularly-ovate. Another term which is appHed to it is Khomboidal
(Fig. :)()()).
Leaf outlines: Fig. 498. Deltoid {Betula). 499. Subulate (diagrammatical). 500. Rhomboidal
{Chekan). 501. Obovate (Lindera). 502. Oblanceolate {SoHdago). 503. Spatulate (Antennaria).
504. Talcsitc (Eucalyptus). 505. Inaequilatcral (//amamcZis).
Forms Broadest above the Middle. — ]\Iost of the forms just referred to
are i)aralleled by exactly similar forms in which the widest portion is
above the middle. The names for these are formed by ])refixing the
syllable oh to the corresponding names of the other forms; as, Obovate
(Fig. 501), Oblanceolate (Fig. 502).
When an. Obovate or Oblanceolate leaf possesses a broad, rounded
ai)ex, and a somewhat elongated lower portion, it is called Spatulate
(Fig. 50;^).
The outline of a leaf is greatly modified when the jxtrtioii U])on one
side of the midrib is longer or broader than that upon the other, giving
us Inequilateral, I'nequal, or Oblique forms (Fig. 505).
182
THE LEAF
Wlien such a leaf has its midril) laterally (•iir\(>(l, it is styled Falcate
or sword-shaped (Fig. 504).
Modifications of this as regards the comparative length and breadth
of the leaf are Sickle-shaped and Scimeter-shaped.
Forms of the Apex. — A large numl)er of terms are employed to indicate
especially the form of the apex of the leaf.
si;e.
SI3.
J/4.
S/X
Forma of apex: Fig. 506. Obcordate (OxaZis). 507. Notched (Linoiieredrore). 508. Abruptly acumi-
nate and acute {Ailanlhus). 509. Emarginate (Pilocarpus). 510. Acute (Lonicera). 511. Abruptly
pointed (Ulmus). 512. Retuse. 513. Abruptly acuminate and obtuse (Fraxinus). 514. Tapering
{Panicum). 515. Blunt (Plantago).
Beginning with one which is inversely cordate — that is, with the
sinus at the Apex — we have the Obcordate form (Fig. 506). When the
sinus is smaller, it is called Emarginate (Fig. 509), and when very slight,
Retuse (Fig. 512). If the sinus be an angular one with straight sides,
it is called Notched (Fig. 507). If the apex be abrui)tly' terminated,
as though cut across in a straight line, it is called Truncate. If any
portion of the apex of the leaf be narrowed into a point, the leaf is
called Pointed (Fig. 511, etc). If such narrowing be gradual, so that the
point is considerably longer than broad, it is called Acuminate. If the
FnR^fs OF riiE base
1S3
ac'umiiiation is preceded hy an abrupt eoiitractioii, it is distiii<,Miislied as
beiiiji: AI)riiptly Aeuininate (Figs. 511 and o\'.'}).
If the narrowing be very gradual and not jjreeeded by an abrupt
eontraetion, the ajjex is said to be Tapering (Fig. 514); if still more
drawn out, Attenuate. If the point of the leaf be extremely abrupt
and very small, it is Mueronate when soft and herbaceous, Cuspidate
when hard and stift', like a tooth.
Fig. 51G. Dioilalia leaf, with produced base, rounded apex, reticulate venation. 517. Apiculatc
apex. 518. Cuneate base (white-oak). 519. Cordate and produced base (violet). 520. Sagittate
base Wolygonum). 521. Aurioulate base (Aster). 522. Hastate base {Rutnex), 523. Oblique base
(Datura).
Any of the above-mentioned forms may be either Acute, when the
ultimate apex is sharp (Figs. 508, 510, and 514), Obtuse when not so
(Figs. 511 and 513), Blunt when very obtuse (Fig. 515), or even Hounded
(Fig. 51(;).
x\ leaf which has the midrib only extended into a bristle-shajjed
point is called Apiculate (Fig. 517), and this condition can apply to a
cordate as well as to other forms of the apex.
Forms of the Base.— The special forms of the base of the lcaf-i)la(le
yiehl a correspondingly large number of* terms. Tlu> terms cordate,
truncate, rounded, blunt, obtuse, acute, acuminate, and abruptly
184 THE LEAF
acuminate, require no definitions in addition to those which have been
apphed to simihir forms of the apex.
When the two sides of the base are straight, and come to an acute
point, it is called Cuneate or Wedge-shaped (Fig. 518).
A base the form of which yields later to a sudden downward ])rolonga-
tion or acumination is called Produced (Figs. 516 and 519).
In all forms of the cordate base the greatest care must be taken to
specify the precise character both of the sinus and of the lobes. The
former must have its form or outline specified, as well as the angle
which it makes. It should, moreover, be carefully noted whether the
leaf-base at the summit of the petiole be produced into the sinus, in
which case it is called Intruded (Fig. 519). Sometimes the lobes of a
cordate base will meet one another, or even overlap.
The forms of the lobes are also capable of taking descriptive titles
similar to those characterizing the lamina in general. The principal
of such terms are Auriculate, when the lobes are rounded similarly
to the lobe of the human ear (Fig. 521) ; Sagittate, when pointing down-
ward, and acute, like the lobes of an arrow head (Fig. 520) ; Hastate or
Halberd-shaped, when turned outward (Fig. 522).
A base is Oblique or Inequilateral when descending lower upon one
side than upon the other (Figs. 521 and 523).
Venation or Nervature. — Bundles which obviously separate from one
another at or near or below the base of the blade, and maintain their
course well toward the apex or margin, are called Costae or Ribs if
equally prominent (Fig. 527), nerves if lateral and markedly less promi-
nent than one or more of the central ones (Fig. 529).
The central one, whether there be others or not, is the Primary or
Midrib (Fig. 524, a). Branches or ribs or nerves are called A'eins, and
they are distinguished as Secondaries (6) when departing from the mid-
rib, Tertiaries (c) when departing from Secondaries, and so on. In
palmately veined leaves, the central is called the IMiddle Primary, the
other, the Lateral Primaries. The middle one is here also called the
midrib, if distinctly stronger than the others. Secondaries of lateral
ribs or nerves must be especially so designated in description. Very
small veins are called Veinlets.
The greatest importance in descriptive terminology pertains to the
classification of leaf-\'enation, owing to the frequency with which leaves
must be identified in such a fragmentary state that there is little beyond
the surface and venation, with possibly a portion of the margin, to
assist us.
VENATION OR NERVATURE
185
The forms all fall within two principal classes, which, in general,
characterize respectively the monocotyledons and the dicotyledons.
The former hears its ])rincipal veins more or less ])arallel with one
another, and these are munerons. Snch lea\es are called I'andlcl-
veined (Fig. 52G).
Venation or Ncrvature: Fig. 524. Pinnateiy veined leaf of Castanea: a, midrib; b, secondaries; c,
tertiaries. 525. Reticulate leaflet of Pilocarpus: a, anastomosis of secondaries. 526. Parallel-veined
leaf of Convallaria. 527. Flabellately costate leaf of Plantago. 528. Digitately veined leaf of Cercis.
529. Costinerved leaf.
In the second form there is hut one, or a comparati\'ely few t)ri<,nnal
veins, and these give rise to successively developed branch systems,
the whole forming a network or Reticulum. Such leaves are called
reticulated or Xetted-veined (Fig. 524, etc.). These veins may or may
not anastomose or intercommunicate at their distal ends. When they
186 THE LEAF
do, the term Reticulate is applied to them in a special or restricted
sense (Fig. 525). In leaves of the last-named class the details of the
method of intercommunicating are very important. Thus, in some cases,
the end of each secondary is arched upward into the secondary next
above (Fig. 525). In such case it is important to note the comparative
distance from the margin at which the communication takes place and
the angle at which the two meet, as these characters are always constant
in the same species. In other cases the secondaries (or the ribs, as in
Fig. 568) are directly connected by straight and parallel secondaries
or tertiaries, or in still others (Fig. 516) by an irregular intervening
network of small veins. Secondaries connected by the first method
are usually also connected near the base with the midrib by a number
of curved tertiaries.
When the principal veins or nerves of a leaf are straight, it is called
Rectinerved; when curved, Curvinerved. The latter term refers to a
regular and characteristic curve, not to a crooked course. Some leaves
are characterized by possessing waving or crooked nerves or veins.
Two great classes of netted-veined leaves are recognized, the one in
which there is a main Rachis or midrib, from which secondaries
extend regularly toward the margin. This form is knowp as the Penni-
nerved or Pinnately veined leaf (Fig. 524), The number of pairs of
secondaries, whether they originate exactly opposite to each other or
somewhat irregularly, is within fair limits characteristic of the species,
and should be stated. The same is true of the angle at which they
radiate from the midrib. In the case of additional ribs or nerves of
such a leaf, their number and stoutness as compared^with the midrib,
their comparative length and the position which they take in the leaf
are all important. The second great class of netted-veined leaves is
that in which a number of approximately equal ribs ra^aliate from the
basal region. Such leaves are known as Palmately>or Digitately
Veined (Figs. 527 and 528). There are, of course, many forms of inter-
grading (Figs. 529 and 568) between such leaves and pinnately veined
leaves with secondary ribs or nerves. Sometimes the nerves start from
the very base of the leaf, in which it is called Basinerved (Fig. 528) ;
at others from the lower portion of the midrib, when it is called Costi-
nerved (Fig. 529). When the ribs or nerves are manifestly continued
downward into the petiole, the leaf is called Flabellately nerved (Fig.
527).
The Leaf-margin. — The manner in which the leaf-margin comes to
deviate from an entire condition has already been indicated. Three
THE J.KAF MAIiCIN
187
special forms of tootliiiii;- arc i-cconni/cd, in accordance with llic form
and direction of the teetli. When the hitter jx.int in an outward direc-
tion the margin is caUed Dentate (Fiji;. ")."54); wlieii toward the ai)ex of
the leaf, Serrate (Fig. I'^'.V^). When, instead of l)einij; pointed, the teeth
are rounded, the margin is Crenate (Fig. 530).
Margins: Fig. 530. Crenate {Daliharda) . 531. Doubly serrate, the teeth appressed (Ulmus). 532.
Obsoletely serrate (.Gaultheria) . 533. Serrate. 534. Dentate (Viburnum). 535. Serrulate (Vibur-
num). 530. Ropand (Hamnmclis). 537. Sinuate.
Diminutives of these terms, indicating that the teeth are very small,
are Denticulate, Serrulate (Fig. 535), and Cremilate. To any of these
terms tiie word "Minutely" may be prefixed as indicating that the
teeth are still smaller. Of each of these three ])riiici])al forms there
are a number of sub-forms.
When the teeth bear smaller or secondary teeth, the word " Doubly"
is prefixed (Fig. 531, (l()ubl>- serrate).
When serrate teeth ha\-e their ])()ints \-ery stronglx' directed toward
the apex or ai)pearing as though pressed inward against the margin,
they are called .Xpprcssed (Fig. o.n , partly). They may even be
Incurved. When, ui)on the other hand, the ends of the teeth are turned
outward, they arc called Salient. When the points of the teeth are very
188
THE LEAP
fine and })ro(luced in tlie form of bristles they are called Spinulose (Fig.
524).
When a margin shows indications of being dentate, serrate, or crenate,
but the teeth are not distinctly pronounced, the adjective Obscurely
is prefixed. For this word that of "Obsoletely" is substituted when
the leaf possesses a relationship such as to make it probable that its
ancestral forms were more strongly characterized by this condition
(Fig. 532).
Fig. 538. Pinnatifid (Pedicularis) . 539. Palmatifid (gooseberry). 540. Laciniately divided (but-
tercup). 641. Slightly revolute. 542. Strongly revolute (i?o.sOTari>ius). 543. Lobed, the lobes acute,
the sinuses obtuse (_Quercus). 544. Both lobes and sinuses obtuse {Sassafras). 545. Lobes obtuse,
sinuses acute (.Hepatica). 546. Incisely parted (Geranium).
When the teeth and their sinuses are all connected in such a way
that the margin represents a wavy line, the latter is called Hepand or
Undulate, or Sinuate (Figs. 536 and 537). When a leaf is so deeply
toothed that the sinuses reach well toward the middle portion (Figs.
543 to 545) the term Lobed is substituted for those above defined.
When the division, by a sharp sinus, extends more than half-way to
the middle, yet not very near to the midrib, it is called Cleft (Fig. 539).
When reaching almost to the midrib (Fig. 538) or to the base in case
of a digitate leaf (Fig. 546), it is called Parted, and when all the way,
Divided (Figs. 540 and 559). The divided leaf is, however, not the same
as the compound leaf, inasmuch as the separation of its blade into
distinct leaflets is not complete. (Compare Figs. 547 and 555.)
The cleft, parted or divided leaf, is either Pinnatifid (Figs. 538, 556,
THE COMPOUND LEAF 189
etc.) or Paliiiatifid ( Fii^s. 540 and 540), accor(lin,ti; to tlic cliaractcr of Its
venation. In all forms of lobed, cleft, parted or <li\idc(i leaves, it is
necessary that the detailed characters of the lohes and of the siinises
should be specified. The lobe may be acute, while the sinus is rounded
(Fig. 543), or the reverse may be true (Fig. 545), or both may l)e acute
or both obtuse (Fig. 548). The sinuses as well as' the lobes frequently
possess definite and characteristic outhnes, indicated by terms such
as have already been defined in connection with the leaf. When the
teeth and sinuses are outUned by straight hues and sharp terminations,
as though notched out by a pair of scissors, the margin is said to l)e
Incised (Figs. 540 and 546). When the divisions and sinuses are long
and narrow in addition to being incised, it is called Laciniate (Fig. 540).
When the margin of a leaf is turned downward or backward or rolled
backward, it is said to be Revolute. Ordinarily the revolution is very
slight (Fig. 541), but occasionally, particularly upon drying, it will be
found extreme, each half of the leaf forming a roll, the two meeting
back of the midrib (Fig. 542).
Before proceeding to speak of the forms of compound leaves, it
should be stated that when one of the terms above defined (and the
same is generally true of descriptive terms used in other parts of the
work) terminates in the ending ate or oid, it sometimes indicates that
the condition tends toward but does not quite reach that named by
the term to which the ending is appended. For example, triangulate
means inclining toward triangular. The student will also note that
between nearly all the forms of leaves and the characters indicated by
the terms above defined, there are intermediate forms connecting them
with others.
Inasmuch as it is necessary in description for such forms to be
indicated, the method is resorted to of employing the two terms con-
nected by a hyphen. Thus, Lance-ovate, or Ovate-lanceolate (Fig.
497) indicates that the form is intermediate between lanceolate and
ovate; crenate-flentate and serrate-dentate are similar illustrations.
A similar intermediate condition is sometimes indicated by prefixing
the term .sub, thus sub-cordate, sub-sessile, sub-acute. Other inter-
mediate terms very commonly employed are acutish and ol)tnsish.
The Compound Leaf.— lii the lohed leaves which we ha\c already
examined, even the most (leei)ly dixided of them, the lobes are seen to
be connected with one another at the base by ])ortions of the conmion
blade, so that a complete division of the blade into separate parts has
not taken place. In the leaves which we are now to examine, such
190
THE LEAF
se])arati()n has occurred, and the lamina has become divided into a
number of distinct secondary bhides (Figs. 54S, .554, etc.). Leaves of
this kind are called Compound, and their divisions, Leaflets.
If the leaflets are themselves compound, the leaf is Decompound.
Decompound leaves are spoken of as once compound, twice compound,
etc., according to the number of successive divisions. Leaflets may be
distinguished from leaves by the fact that no buds are found in their
axils. Leaflets are subject to the ai)i)lication of the same descriptive
terminology as leaves.
Leaflets of the first division are called Pinnae, those of subsequent
divisions, Pinnules.
The continuation of the petiole passing up among the leaflets, that is
the midrib of the compound leaf, is the rachis (6, Fig. 475).
Fig. 547. Palmately compound leaf {Aesculus). 548. Palmately trifoliolate leaf (Trifolium) . 549.
Pinnately trifoliolate leaf (.Lespedeza) . 550 and 551. Unifoliolate compound leaves of orange.
When, as in Fig. 548, the compound leaf has no rachis, its division
being on the same plan as the lobing of the palmatifid leaf, it is Palmate,
or Palmately compound. When the rachis does exist, corresponding to
the pinnatifid type (Figs. 549 and 554), the leaf is Pinnate, or Pinnately
Compound.
Before proceeding to define the distinct forms of the two classes, we
note that it is not always possible to identify them with readiness. For
example, the ancestral form of the leaf of the orange was pinnate, but
at the present time we find that only the terminal leaflet remains,
there being usually at the base more or less of an indication of the two
lateral leaflets which once existed (Figs. 550 and 551). Such a leaf
cannot, therefore, be properly designated as simple, and we designate
it as a Unifoliolate compound leaf.
Compound leaves with three leaflets, usually designated as Trifolio-
late, frequently give us considerable difficulty in determining whether
77//'; COMl'Oi'MJ Lh'AF
191
tlu'v arc i)iiiiiatc'ly or ])almatoly coinpouiKl. Tlic (iiu'stioii is to l)e
decided in aeeordaiiee with tlie i)()iiit a( wliieii disarticulation of the
tenniiial leaflet occurs. If ])alniate, the \):\>v of the blade must ))e the
point at which the three petioles separate, so that when disarticulation
occurs no rachis will remain extending l)ey()nd the j)oint of attachment
of the two lateral leaflets (Fig. 548). In the })innate form such a rachis
Fig. .'io2. Triternate leaf. 553. Pedatetloaf (violet). 554. Pari-pinnate leaflet of Gcdilschia. 555.
Impari-pinnate leaf of rose. 556. Millifoliolate leaf of Achilldea 557. Interrupteilly-pinnate leaf
of Aqrimonia. 558. Runcinate leaf of dandelion. 559. Lyrate leaf of barbarea.
(Fig. 549, a), although frequently very short, does exist. In the family
Leguminosae, the question of whether a leaf is pinnately or palmately
trifoliolate is of fundamental importance in classification.
A three-parted j)almately com])ound or divided leaf is called Ternate;
a five-parted one Quinate, a se\en-parted one Se])tate.
A palmatifid (or i)alinate) leaf, with very narrow di\ isions, is called
Pedate (Fig. 553).
192 THE LEAF
If the divisions of such a leaf are similarly compound or divided,
appropriate terms are formed, such as Bi-ternate (Fig. 552), Tri-ternate,
and so on. Similarly named sub-divisions of the pinnate form exist,
the bi-pinnate (Fig. 563), tri-pinnate (Fig. 556), and so on.
These terms are also sometimes applied to the similar divisions of
pinnatifid leaves. Just as we have found that the number of pairs of
primary veins of the simple leaf is generally characteristic of the species,
so we find that the number of pairs of pinnae, technically known as
Jugae, is equally so. This number, therefore, should always be stated,
the leaf being designated as Bi-jugate, Tri-jugate, Multi-jugate and
so on.
Two classes of pinnate leaves are recognized, in accordance with
their termination in a pair or in a single terminal leaflet. Those ending
in a pair (Fig. 554) are called Pari-pinnate, Even-pinnate, or Equally-
pinnate, the others (Fig. 555) Impari-pinnate, Odd-pinnate, or
Unequally-pinnate.
When the divisions of a pinnate or a pinnatifid leaf are alternately
large and very small (Fig. 557), it is called Interruptedly-pinnate or
Pinnatifid.
When the leaflets or divisions are turned backward so that they
point more or less in the direction of the base (Fig. 558), the leaf is
Runcinate.
When the terminal division is very much larger, especially broader,
than the lateral, the leaf is Lyrate (Fig. 559).
Modified Leaves. — Coming now to consider the subject of character-
istic modifications in the form and function of the leaf, we note that
some of them pertain to the entire leaf, others to its individual parts.
We also note that in some of the modifications the entire leaf or one of
its parts retains the ordinary functions of absorption and assimilation,
the new function being added thereto either by partial change of the
entire leaf, or the complete modification of one or more of its parts,
while at other times the original functions are entirely lost.
Carnivorous Leaves. — The function of absorbing and assimilating the
ordinary forms of nutriment is sometimes supplemented by that of
absorbing and assimilating animal tissue. In this case the leaf pro-
vides special forms of apparatus for enticing, intoxicating, or mechan-
ically catching, killing and digesting the animal, commonly an insect.
The Pitcher Plant. — One of these forms is illustrated in the pitcher
plant (Fig. 560), in which one portion of the leaf becomes converted
into a vessel containing liquid of variable origin and complex compo-
ETIOLA TED LEA YES
193
sition. U])()n the outer portion of the ])itc'her a Hue of ghiiiduhir tissue
stretches downward. The insect feeds ujjward along this line of secre-
tion, which so changes its nature toward the toj) of the pitcher, that
by the time the insect reaches that point he is more or less intoxi-
cated, and on crossing the margin, or quickly thereafter, falls into the
liquid and is drowned, digestion prom])tly occurring by means of
enzymes excreted into the liquid by special glands located upon the
inner face of the i)itchcr.
Fig. 560. Modifitd (pitcher) leaf of NepeiUhcs. 561. Modified leaf of Die
The Venus' s Fhj-fntp. — Another form is the well-known ^'enus's
fly-trap (Fig. 5()1), which secretes a nectar by certain glands which
surround its margin. The insect, alighting upon this point, is instantly
seized through the sjiasmodic coming together of the two lateral halves
of the leaf, which act precisely like the jaws of a trap. Digestive fluids
are then immediately poured forth from special glandular tissues on
the leaf-surface and digestion and absorption take i)lace. That the
nutrients thus absorbed are of service to the ])lant has been proved by
elaborate experiments, in which the eflfects of such feeding have been
estimated by comparing their re})roduction with that of other similar
plants, similarly treated in all respects except that they were dei)ri\ed
of this form of food.
Etiolated Leaves. — In other cases, the ])lant being nourished by
means of fully prepared nutrients absorbed from other leafy plants
(host-plants) upon whicli they are parasitic, the leaves lose the chloro-
phyll tissue uj)()n which their ordinary functions (lei)cnd, and arc
known as Etiolated leaves. They become reduced in size and scale-like
in form.
13
194
THE LEAF
Plants which grow in excessively dry or desert regions, and Avhich
are thus ^'ery liable to suffer from excessive evaporation, ordinaril}-
have their leaves modified in some way so as to guard against this
Fig. 562. Phyllodiuni of Aaicia. 503. Leaf of Acacia with blade present. 564. Loaf of Eichomia
with inflated petiole. 505. Cirrhose stipules of Smilax. 566. Aculeate leaf of Rubus. 567. Cirrhif-
(Tous leaf of pea. 568. Leaf of Tococa, its inflated petiole the home of ants. 569. Cirrhose petiole
of Clematis.
tendency, and are called Xerophytic. They may become merely
reduced in size or may be otherwise modified, so as to reduce the
amount or the degree of activity of their epidermal tissue, or they
FLORAL LEAVES OR BRACTS 195
may disappear altogether, or become transformed into organs of a
different character. In one of tliesc forms the leaf becomes converted
into a s])ine, or a grou]) of s])ines, each consisting of one of the teeth.
In this condition the leaf serves an important function in protecting
the plant against destruction by desert animals.
Phyllodia. — At other times the blade (Fig. 5().'^, a) entirely disappears,
a false blade (Phyllodium, Fig. 5()2), of much less activity as an evapor-
ating organ, becoming formed by the flattening out or exi)ansion of
the petiole (Fig. 553, c). A phyllodium is readil>- distinguished from a
leaf-blade in that its broad surfaces are directed laterally instead of
vertically, as in the true lamina.
Leaves as Floating Organs. — Leaves or their petioles frequently
become luodified into floating organs in aquatic i)lants, as in the case
of the bladdery-inflated petioles of the Eichornia (P'ig. 504).
Somewhat similar inflated organs exist upon the petioles of some
plants and serve as the homes of colonies of ants, which are efficient in
protecting the plant against the attacks of certain animals (Fig. 568, a).
Leaves as Climbing Organs. — The office of climbing is frequently
])crf()rnH'd by a portion of the leaf. In some cases, as the Clematis
(Fig. 569), the petiole of the leaf becomes twining for this purpose.
At other times the apex of the rachis (Fig. 567) becomes a tendril,
either simple or branching, while at others the entire leaf becomes thus
modified. In the Smilax (Fig. 565) it is the stipule which is thus
changed. In other cases (P'ig. 566) climbing is effected by means of
hooks develoi)ed u])on some ])ortion of the leaf.
Floral Leaves or Bracts. — Besides protecting the i)laut by becoming
converted into spines or spine-bearing organs, as above described, the
leaf is subject to various other modifications having this object in view.
Ucfert-nce lias already been made to such modifications in the form of
bud scales. For the i)rotection of the flower exist the epicalyx and such
scales, called Floral Leaves or Bracts, as have been described in our
opening account of the flowers of the willow.
Floral leaves or bracts do not always exist merely for jjurposes of
protection. In very many cases they are functionally a i)art of the
flower structure, surrounding either single flowers or clusters of
flowers, and ser\ing by their large size or brilliant coh)rs, or
both, to attract insect-\isits, i)rccisely the same as has be(Mi described
in reference to the i)erigone. Through the floral bracts thus modified,
we get a direct transformation into the ])arts of the perigone, as has
already been sufficiently explained. It is also important to note that
196 THE LEAF
a direct relation is to be traced between the definite arrangements of
foliage and floral leaves, as will be considered under Phyllotaxy, and
the arrangement of the parts of the flower itself; so the characteristics
or praefloration are seen to be directly dependent upon the phyllotaxy
and praefoliation.
Phyllotaxy. — In view of the established fact that the development
of the branches follows that of the leaves, it becomes clear that the
arrangement of the latter determines the entire symmetry of the
plant, with all the far-reaching consequences in connection with both
vegetation and reproduction. Certain definite laws of phyllotaxy
having been ascertained, the forms resulting become, in their different
manifestations, of nearly fundamental importance in classification and
in diagnosis.
The Whorled Arrangement. — We find that either one or more than one
leaf is developed from a node. In the latter case the arrangement is
called Verticillate or Whorled, and the circle a Whorl or Verticil. If
the Whorl contain but two members, they are called Opposite — that
is, the centers of their points of insertion are separated by one-half the
circumference, or their Divergence is 180 degrees. Usually the other
nodes are similarly clothed, except that in all of the higher plants the
leaves of each pair Decussate with those of each adjacent pair — that is, a
leaf of one whorl is over the center of the sinus of that next below (Fig.
570). Four vertical rows (Orthostachies) of leaves thus appear upon
such a stem (Fig. 573). If, instead, there be three leaves to the whorlj
six orthostachies will result; if four, eight; and so on. It frequently
happens that the number of leaves in the upper or lower whorls will
contain only half the number of leaves in the others, and still higher
up the whorled arrangement may be lost, the leaves becoming arranged
as in the form next considered.
The Alternate or Spiral Arrangement. — By the other arrangement the
nodes produce solitary leaves, so that each leaf is successively produced
at a higher level. If a line be traced from the point of origin of one
leaf to that of the one next above, and continued in the same direction,
so that it exactly meets the point of insertion of another, and then of
another, and so on, it will at length meet one exactly over the point of
starting — that is, a second leaf in the same Orthostachy (Fig. 571).
It will then be found that the line followed is a spiral, which has passed
once or more around the stem. Such a spiral is called a Cycle, and if its
line be continued, it will form other similar cycles above and below. It
is observed that a cycle will be limited by two adjacent leaves of one
THE ALTERNATE OR SPIRAL ARRANGEMENT
197
Ortliostacliy. Thus, if loaf No. 4 is the next in tlie orthostachy, to
which leaf No. 1 belongs (Fig. 574), three lea^■es will belong to that
cycle. A cycle containing three leaves makes but one turn of the stem.
A cycle is expressed in the form of a fraction, its numerator indicating
the number of times it encircles the stem, its denominator the number
of leaves which it includes, so that the cycle last described must be
indicated by the fraction one-third. The angular divergence of its leaves
is 120 degrees. If the next leaf in the same orthostachy as No. 1 be
No. G (Fig. 572), then that cycle will contain five leaves. A cycle
containing five leaves makes two circuits of the stem, so that its exponent
Fig. 570. Decussating opposite leaves. 571. Alternate or spiral leaf-arrangement. 572. Diagram
of the same, the f, arrangement. 573. Diagram of 570, showing its 4 orthostachies. 574. The j spiral.
575. The ,; spiral.
will be two-fifths. If the second leaf of the orthostachy were No. 9, the
appropriate fraction would be three-eighths, the cycle making three
turns and containing eight leaves (Fig. 575). It will thus be observed
that these fractions form a series, in which each possesses a numerator
equal to the sum of the numerators of the two preceding and a denom-
inator equal to the sum of the denominators of the two preceding. No
cycles occur among the higher plants with which we are concerned,
which can be indicated by any fraction not thus formed.
Noticing these fractions still further, we obserxe that tlic (Iciioiiii-
nators will indicate the number of orthostachies upon the stems which
198 THE LEAF
they represent, and that the value of the fraction will represent the
divergence of, or part of a circle between, any two leaves adjacent in
the cycle or spiral — that is, the number of degrees between such leaves
will equal that fractional part of 3()0 degrees.
Antidromy. — As to the direction which the spiral takes, it may be
either from right to left or from left to right. It is supposed that each
kind of plant, at least of the higher classes, produces two forms or
"castes," depending in some not yet perfectly determined way upon
the relative positions of the respective ovules from which they originate.
The tendency of these two castes to manifest their growth or develop-
ment in opposite directions has been called Antidromy. Among numer-
ous other phenomena attributed to antidromy is this starting of the
leaf-spiral in opposite directions in plants of the two castes of any
species with this form of phyllotaxy.
The Scattered Arrangement. — Occasionally, leaves appear to be
irregularly disposed upon the stem — that is, they are not whorled, nor
does the law of alternate phyllotaxy appear to apply to them. This
arrangement is called Scattered, and the explanation is dift'erent in
different cases.
Tufted Leaves. — When a stem is so shortened that the leaves are
crowded upon it in the form of a regular rosette, as in the house-leek,
the arrangement is called Tufted.
Fascicled Leaves. — ^When similarly short, but the leaves few and
irregularly crowded in a little bunch, the arrangement is Fascicled.
The two regular forms of leaf arrangement above described can be
traced in greater or less perfection through floral bracts and involucres,
and into and in many cases partly or wholly through the flower itself.
While such arrangement in the flower is in many cases entirely verti-
cillate and in most cases partly so, it has been quite clearly shown that
many flowers have certain of their parts arranged ui)on the spiral ])lan.
CllArTKIJ XVll
ANTIIOTAXY
The aiTangcment of flowers is called their Aiithotaxy, and this name
is also ap})lied to the study of inflorescences.
The Inflorescence. — That part of a stem or branch which bears the
flowers, or the flower when solitary, is more or less distinctly modified
in form, surface, modification of its leaves, extent and character of
branchinff, and frequently also in the direction taken in the arrange-
ment of its parts. In connection with its flowers it is called the Inflor-
escence.
The stem of an Inflorescence, that is, the portion which is below its
lowest point of branching or flowering, or below the flower when solitary,
is called the Peduncle {a in Figs. 57() and 583). This name is also
applied to the corresponding portion of a branch of an inflorescence if
that branch bear more than one flower, it being in that case a Secondary
Peduncle (Fig. 584, d).
The Rachis. — If the peduncle is continued above its first point of
branching, in the form of a central support along which the succeeding
branches or the flowers are arranged, this portion is called the Uachis
(Figs. 583 above a and 58(5, a).
The Scape. — A peduncle which rises directly from or near the ground
is called a Scape (Fig. 57(5, a).
The Pedicel. — The stem of one of the iii(h\idual flow(>rs of an inflor-
escence of more than one flower is called a JVdicel (r, in Fig. 584). A
flower or an inflorescence may be devoid of i)e(licel or ])eduncle, when
it is Sessile.
The arrangement of the infloresc(Mice-lea\es and their lloral branches,
while based upon the phyllotaxy, and traceable thereto in most cases,
exhibits more or less real or apparent departure therefrom, and calls
for special designations and classification.
The Determinate form of Anthotaxy. — The forms of flowering are
di\i(led into two scries in accordance with the a])ical or lateral location
of the initial fiower — that is, the flower which is first in order of develop-
ment. If the terminal bud develop into a flower (Fig. 57(5) its further
200 ANTHOTAXY
extension is impossible, except by the rare and abnormal process of
Proliferation. Inflorescences so limited are called Determinate or
Definite.
Vertical Extension by the Branches. — Although vertical extension of
the original stem of a determinate inflorescence is not possible, it can
take place through the branches, the same as in other sympodia. The
effects of such development are the same as in other forms of sympodial
growth in which there is a transformation of the apex of the original
stem — as, for instance, in our explanation of such a mode of develop-
ment of the tendril (Fig. 431). To apply this principle in the case of an
inflorescence, we have only to assume a flower developed at the tip of
every branch in Figs. 433 to 435. Flower a would develop first; h,
although the second in order, and hence a branch, and afterward c,
would be more elevated, and would thus seem to prolong the vertical
extension of the stem. The development being successively by nodes
whose original points of origin were successively lower than that of the
terminal flower, is structurally and really Descending or Basipetal,
even though by the upward growth of the successive branches they be
at successively higher levels, the order apparently in the opposite
direction. By the development at each node of a pair of opposite
branches we get the apparent bifurcating or dichotomous form (Fig.
435). If but one branch grow from a node, and these successively from
right to left, the zig-zag or Flexuose form of rachis is produced (Fig.
433), and if constantly from the same side, or apparently so, the Cir-
cinate (Fig. 434).
The descending or basipetal nature of the definite inflorescence is
clearly shown when the successive branches remain short, each succes-
sively developed flower remaining at a lower level than that which
preceded it (Fig. 581).
The Centrifugal Form. — Instead, however, of assuming either of these
two states, in which the flowers remain at different levels, the branches
may radiate and elongate to different degress, ceasing their elongation
when their flowers have been brought to a uniform height, so that a
more or less flat-topped inflorescence results, the order of development
being from the center outward, or Centrifugal, as in the branches of
Fig. 584.
Cymose Inflorescences. — This form represents the true Cyme, and
because of their relationship to it this entire series of inflorescences is
often denominated the Cymose. It will thus be seen that in different
forms of the cymose inflorescence, we may have the flowers all brought
THE INDETERMINATE FORM OF ANTIIOTAXY
201
at length to a uiiiforni level, those of successively later (leveIo])ment
brought to successively higher ])oints, or left at successively lower
le\-els. This fact demonstrates that the cyniose or descending nature
of an inflorescence cannot be determined by noting the relative heights
of the flowers themselves, but only by noting the order of their
development.
JS2
MJ.
J^SJ. J86
Fig. 576. Scapo.sc 1-flowored peduncle of tulip. 577. Corymb of Crataegus. 578. Head of Cepha-
lantll^ls. 579. Umbel of ^Lscifpias. 580. Secund raceme of fiicucw/^o. 581. A descending inflorescence.
582. Ordinary raceme. 583. A spike. 584. Compound cyme of Saponaria. 585. Globular spadix
enclosed in spathe of Spathyema. 586. Cylindrical spadix of Acorus.
The Indeterminate Form of Anthotaxy. — In the second series, the first
flower to develop is structurally the lowest of the cluster, the succession
being upward. Ascending or Acropetal (Figs. 582 and 583). If the
successive branches develop less rapidly than their predecessors,
the result is again a flat-topped inflorescence, with the development
from the outside to center, or Centripetal (Figs. 577 and 579). The
branches and flowers may be separated on obvious peduncles and
pedicels, or these may be not apparent, the flowers being sessile. In
accordance with the characters above explained, we obtain the following
simple forms of anthotaxy:
202 ANTHOTAXY
Series 1
Ascending, Acropetal, Indefinite, Indeterminate, Centripetal, or
Botryose Forms.
A. With the rachis not elongated.
1. The Capitulum or Head, with the flowers, and branches,
if any, sessile or so regarded (Fig. 578).
2. The Corymb, with the rachis manifest, though short, and
its pedicels or branches elongated so as to produce a
flat-topped inflorescence (P'ig. 577).
3. The Umbel, similar to the Corymb but with the rachis
not manifest, so that the pedicels or branches all appear
to start from one point at the summit of the peduncle
(Fig. 579).
B. With the rachis elongated.
4. The Spike, with the flowers, or branches, if any, sessile or
so regarded (Fig. 583).
5. The Catkin or Ament, a spike with slender rachis and
bearing usually staminate or pistillate flowers, crowded
and subtended by scales (Figs. 8, 11, and 15).
6. The Raceme, similar to the spike or ament, but having
the flowers pedicelled (Figs. 580 and 582).
When either the head or spike possesses a thick, fleshy,
rachis it is called a Spadix (Figs. 585 and 586).
Series 2
Descending, Basipetal, Definite, Determinate, Centrifugal, or Cymose
Forms.
1. The Glomerule, corresponding to the head in all respects
save that the central flower first develops.
2. The Fascicle, similar to the glomerule except that the
flowers are few and loosely clustered.
3. The Cyme, similar to the corymb or umbel, save that
the central flower is the first to develop (Fig. 584).
4. The Scorpioid Raceme. Similar to the raceme, except
that each successive node and flower upward is lateral to
that next below. The apex of the scorpioid raceme is
circinately coiled (Fig. 434).
THE ANTIIODIUM 203
Compound Inflorescences. — Before ])r()ceeding to consider certain
speciul forms and inodificatioiis of the inflorescences above defined,
it should he remarked that most of the forms may be comi)ouiid. By
this we mean that the chister is made up of a number of l)raneiies whose
order of devel<)i)ment is the same as that of the elements of which they
are composed. That is, the raceme may i)ossess a number of branches,
each of wliicli is a smaller or secondary raceme, or if not a raceme, at
least a small inflorescence of the ascending or centripetal form. Similarly,
an umbel may be made up of branches, each of which is a smaller umbel,
the Umbellule. A cyme will be made up of cymules, and so on. A
Panicle is a compound raceme which assumes the form of a pyramid.
Any form of inflorescence not a true panicle, but assuming the shai)e
of one, is styled Paniculate.
Complex Inflorescences. — Complex forms of inflorescence differ from
the compound in that the order of development of the several flowers
upon a branch is of a different kind from that of the several branches
themselves. For exmaple, the ThjTsus or Thyrse is a paniculate form
in which the lowest branch is the first to develop flowers, so that the
order of development of the branches is ascending, but within a branch
the terminal flower will be the first to develop, so that the order of
development of its flowers is descending. In the same way, each
branch of an umbel may terminate in a head; or we may have a fascicle,
each branch of which is a raceme.
The Anthodium. — The term Anthodium has already been defined in
considering the forms of the fruit, under Multiple or Collective Fruits.
The same term is a])plied to an inflorescence yielding the collective
fruit of that name (Fig. 587). It is in reality nothing more than a head
closely subtended, surrounded or enclosed by an involucre (a). The
anthodium is characteristic of the great family Compositae, and is of so
much importance in classification that its modifications call for special
attention. The involucre should be studied as to whether it is single,
double, or multiple — that is, whether it consists of one, two, or more
circles of scales; as to whether these are equal in length or whether the
outer or inner are successively shorter; whether they are entirely free
and distinct, or adnate by their bases or comiate by their margins; as
to whether they are appressed, or with more or less of their apical
portions recurved or spreading; esi)ecially as to the general ft)rm of
the involucre as a whole, the terms used being the same as those i)re-
viously applied to the perigone, and as to the characters of the individual
scales, these being })ractically the same as those which have already been
considered in connection with the leaves. The Ixxiy consisting of the
204
AN T HOT AX Y
combined tori of all the flowers of the anthodium, is called a Receptacle
(b). It is to be studied as to its being solid or hollow; as to its general
form, and especially the form of its upper surface, whether concave,
plane, convex, rounded, or conical; as to its being smooth in surface,
honeycombed or otherwise, pitted (foveolate), and if the latter, the
special characters of the pits and their margins; and as to its being naked
or clothed with hairs or scales, and the characters of the latter in their
every detail. The head is then to be considered as to the character of
its flowers. If these are all sexually similar, the head is said to be
Homogamous; if different, Heterogamous. If the flowers are all ligu-
late, the head is Liguliflorate. If it possess a disk (e), of tubular flowers
(d), it is Discoid. If this disk is surrounded by one or more circles of
Fig. 587. Vertical section through an anthodium: a, involucre; b, receptacle; c, disk; d, disk-
flower; e, ray-flower.
ligulate flowers called Rays (e), it is Radiate. If the ray-flowers and
disk-flowers are of the same color, the head is Homochromous; if
different, Heterochromous. The flowers must next be studied as to
their sex. The ray-flowers are commonly pistillate, while the disk-
flowers are perfect, or the disk-flowers may vary among themselves in
this particular. Very commonly, the ray-flowers are entirely neutral.
Even if pistillate, they may be sterile. If both classes of flowers are
fertile, the akenes which they produce may be heteromorphous, those
of the disk being commonly compressed, those of the rays commonly
triquetrous. Occasionally the heads are dioecious or monoecious. In
one tribe of the Comjjositae the corollas are bilabiate. The character
of the pappus (Figs. 74 to 83) is invariably of the utmost importance.
INFLORESCENCE-LEAVES OR FLORAL LEAVES 205
as are the forms of tlie style-branches and the api)enfhiges l)oriie by
these at the apex and by the anthers at apex and at l)ase (see Anth'oe-
ciuni and Gynaeciuni).
Inflorescence-leaves or Floral Leaves.-Many special terms are applied
to the forms of inflorescence-leaves, that is, the bracts subtending its
branches and the ])edicels of the flowers, as wellas those borne upon
the pedicel. Ordinarily they are conspicuously smaller than the other
leaves borne by the ])lant.
With this reduced size, other modifications are noticeable, csj)ccially
the shortening or loss of the petiole and a general tendency toward
reduction to the scale-form, this tendency counteracted in variable
degree by a contrary tendency to preserve the characteristic leaf-form.
These leaves are commonly spoken of as the Reduced Leaves of the
Inflorescence. To this class belong the leaves of the in\-olucre and the
scales often found upon the receptacle of the anthodium already con-
sidered. Individually, they are spoken of as bracts, the secondary ones
bractlets, and the ultimate very small ones bracteoles. Ordinarily the
changes here outlined as marking the development of the foliage-leaves
into the inflorescence-leaves are gradual, but in many cases there is an
abru])t transition from the one form to the other.
A circle or cluster of bracts at the base of an inflorescence is termed
an Involucre, and this term is also applied to a single very large bract
occupying the same position, although this is more commonly known
as the Spathe. In most cases the modifications of lca\es forming the
scales of involucres are entirely dift'erent from those of bracts occin-ring
singly. They are usually much larger than such bracts, their form is
usually specialized in some way, and they are very frequently highly
colored, serving the same purpose as neutral flowers. The l)racts of
involucres are often amalgamated so as to form a cu]) or tube.
Many one-leaved involucres are very peculiar, and their mori)holog>-
even more difficult to understand. The supposed leaf is sometimes a
phyllocladium. In some cases the flower appears to rise out of the
modified or unmodified leaf itself, as in the Tilid, the explanation in
these cases probably being that adiiation exists between tlie inflores-
cence and the leaf.
One group of Families, the grasses and grass-like plants, do not
possess any obvious perigone, its place b(>ing snp]ih'ed by peculiarly
formed, adapted, and arranged bracts, in tlic form of scales or chafl",
and technically called Glumes, which give to this gronj) of families the
title Glumaccae. In the rushes, these glumes really are a true
perigone, whicli is trinierous. In the sedges (Family Ci/pcrarcoe,
206
ANTHOTAXY
Fig. 588) the scales (a) are solitary, subtending each flower. In the
grasses (Family Gramincae) the glumes are arranged in pairs, each
pair subtending a short branch, which may bear only one, several, or
many flowers, the whole known as a Spikelet (Fig. 589). Typically,
there is besides the two glumes of the spikelet (a) an additional pair
of scales (c) for each flower (6). Thus, if there be but one flower in a
spikelet, it possesses two pairs of scales. If more than one, then there is
a separate pair of scales for each flower, besides the one pair pertaining
to the spikelet as a w^hole. The scales of the spikelet are called the
Fig. 588. Distichous arrangement of flowers of a sedge, each scale (o) containing a flower {b). .589.
Spikelet from the inflorescence of a grass: a, glumes of the spikelet; t, a flower; c, palets of the flower.
Glumes, Glumes Proper, or Lower Glumes; those of the individual
flowers (c) Palets or Upper Glumes. Much complexity in the relations
of the glumes ensues as a result of suppression of both glumes or both
palets, of one of either or of each, or of two of one and one of the other,
and so on. The character of the individual glumes must be carefully
studied, as in the case of the involucral scales of the anthodium. The
character of the terminal appendages wdiich they bear is of special
importance.
With this study of the inflorescence we are brought again to the
individual flower, with the study of which we commenced.
CHA VTKU X \M I I
GENERAL CHARACTERS OF CRYPTOGAMS
Essential Characteristics. — The essential characteristic of tlie flower,
distinguishing it from all other similar reproductive structures, is its
possession of a special tissue which constitutes a soil in which the
microspore germinates, and in which the male gametophyte develops
and grows. Plants destitute of such an organ are therefore knowm as
Flowerless Plants, An equally great or even greater distinction is
found in the fact that the embryo of such plants, resulting from the
conjunction of the male and female gametes, is not located in a resting
body (the seed), but must continue its uninterrupted development into
the sporophyte. They are, therefore, often designated as Seedless Plants.
Flowerless or seedless plants are technically known as cryptogams.
Alternation of Generations. — Our account of the development and
reproduction of Phanerogams has shown that each individual passes
alternately through two difi'erent forms of life, each of which is repre-
sented by its characteristic body form. Those plants which present
themselves conspicuously to view as trees, shrubs, and herbs are sporo-
phytes, producing spores in ovules and anther cells, these spores ger-
minating to produce respectively the male and female gametophytes,
which constitute the other form of the plant body, or the alternating
generation, and which are too minute to be seen with the naked eye.
The sexual elements borne u{)on these gametophytic plants unite to
produce an embryo which is the young body of a new sporophytic
generation, and which is enclosed in the seed. Such an alternation of
generations occurs also among Cryptogams. In some cases the incon-
spicuous generation is the gametophyte (Fig. 599), as in Phanerogams;
in other cases the relations are reversed in this regard (Fig. 59G).
Among many of the lower forms this process does not occur, each ])lant
always reproducing to form a body exactly like itself, witii no indica-
tion of generations ])resenting distinct forms.
The Cryptogamous Plant-body. — (ireat as arc the dillerences seen
among Phanerogams, e\en greater ones are to be seen among those of
Cryptogams. They freciuently present themselves as herbs, shrubs
and trees, with wcll-(ieveloj)e(l leaves, borne upon regularly occurring
phytomers. In other cases, the stem-structure is well developed, while
208 GENERAL CHARACTERS OF CRYPTOGAMS
the leaves are rudimentary in ditt'erent degrees, from those which
want only the most perfectly develoi)ed leaf-structure to those which
are mere scales, consisting of a single layer of flattened cells. By far
the greater number, comprising the lower classes, have nothing which
can be described as homologous with the leaf, the plant consisting of a
simple body which, presenting many different kinds and degrees of
variation in form, habit, and function, yet never shows any indication
of the regularly jointed structure characteristic of the higher plants,
nor any leaves.
Equally great is the variation observed among the roots. Many of
the higher forms possess true absorbing roots, but probably a great
majority of roots among Cryptogamous plants are false roots or rhizoids,
existing for purposes of fixation only.
Lacking, as these plants do, the elaborate structures whose character-
istics have enabled us to identify, describe, and classify the higher
plants, we are obliged to look for such characteristics among the differ-
ent arrangements of their cells. Since this work requires the aid of
the compound microscope and considerable technical skill, entirely
new methods of examination become necessary. We do not, therefore,
find it practicable to consider them in detail here.
The cellular structure of these plants may extend itself in the three
directions of solid bodies, giving us masses of tissue, or they may multi-
ply in two directions only, giving us flat or superficial bodies, or they
may be joined merely end to end, producing filamentous forms. These
bodies may each constitute a single plant, or their cells may cohere
merely by habit, each living equally well if separately detached ; or they
may normally live in a separated condition, thus giving us perfect plant
bodies, each consisting of but one cell, the unicellular plant.
These imicellular plants, furthermore, vary most widely in their
own structural characters. They may be of microscopical size, or they
may become many feet in length. They may possess the simplest
structure, or they may develop large cavities, which are divided and
subdivided by processes developed from the wall, and be shaped into
remarkable forms, yet without true cell division or multiplication.
Vegetation. — Regular vegetative processes are of course required
wherever growth occurs, wherefore we must look for them among even
the simplest forms. In many cases, these processes are as simple as the
bodies themselves. Absorption from a surrounding fluid medium by
the entire body of the plant, with the simplest of chemical transforma-
tions, may exist, or roots or other special organs of absorption, with
REPRODUCTION 209
coniplicated systems of metaholism and conduction, may l)e developed.
Chlorophyll is present in the higher groups, and the vegetative processes
are very similar to those which we have before considered. In other
classes chlorophyll is wanting, and the plants are hence unable to
perform the constructive assimilation which we have found among
most Phanerogams, but ready formed compounds, or those readily
broken down into the required form, must be found for their support.
Reproduction. — We find among the reproductive processes in Crypto-
gams almost as great a diversity as among their other characters. Not
only do both vegetative and sexual forms exist, as among Phanerogams,
but while many groups exhibit both forms, others possess only the
vegetative. Among the higher classes, the vegetative forms of repro-
duction are quite elaborate, involving phytomer-like parts, either singly
or in bud-forms, while in other cases it can occur by single leaves or
parts of them. Among the lower classes, where phytomers and leaves
are unknown, these processes are necessarily simpler. In their higher
members, masses of tissue, often specially constructed, called gemmae or
buds (but of course not conspicuously homologous with the buds which
we have studied), separate to form new plant-bodies, the process being
called gemmation. In other cases the process is the simplest possible
one of cell-division.
Sexual reproduction among cryptogams is too variable to be here
considered, even in a general way. In no Cryptogamous plant, how-
ever, is there developed any structure which combines the varied
functions of that which among Phanerogams is called the flower. The
extension of this term to any reproductive organ of the former group,
merely because certain homologies have been discovered between
them and the flower, is misleading, as it tends to magnify slight resem-
blances into a higher degree of importance than great differences, and
it furthermore subverts the original and fully established meaning of a
common term into a new, even if it were a strictly accurate, application.
When alternation of generations occurs, with the production of
distinct gametophytes, the male cells, in the form of antherozoids, are
usually i)rovided with some independent power of locomotion for
reaching the female element, known as the Central ( 'ell, within a tlistinct
organ called by various names.
It has already been stated that the spores germinate for the ])r()duction
of these gametoi)hytes in any suitable soil, and that the resulting
embryo continues its development without passing into a resting or
seed stage.
14
210 GENERAL CHARACTERS OF CRYPTOGAMS
PRINCIPAL GROUPS OF CRYPTOGAMS
The main groiii)s of the cryptogams are indicated in the following
table:
1. Thallophyta or Thallophytes.
(a) Fungi.
(6) Algae,
(c) Lichenes or Lichens.
2. Bryophyta or Bryophytes.
(a) Hepaticae or Liverworts.
(6) Musci or Mosses.
3. Pteridophyta or Pteridophytes.
(a) Eqiiisetaceae or Horse-tails.
ih) Lycopodiaceae or Club-mosses,
(c) Filices or Ferns.
Each of these groups will be briefly considered, in so far as relates
to its contributions to the materia medica.
Thallophyta.— r/^e Fungi. — The Fungi comprise plants destitute of
true chlorophyll, and therefore incapable of building up their own
food from elementary substances. Their structural and physiological
characters are exceedingly varied.
To the Fungi belong the Bacteria, contributing the great majority
of disease germs, in the special uses of which we are yet to find the
most important part of our materia medica. The study of this group
pertains to the subject of Bacteriology.
To the F'ungi belong also the yeast plants, valuable medicinal agents,
but unicellular, and to be studied only in the microscopical laboratory.
Among the drugs of interest to commercial pharmacognosy, occur
only Kefir grains, Taka-diastase, Ergot, and the Agarics, all of which
belong in the higher divisions of the group.
The vegetative portion of the Fungi consists of a tissue called
Micelium, formed of filaments, often growing into large and dense
masses. In many, this micelium, after forming into a hard mass,
becomes dormant, and constitutes a resting body called the Sclerotium
{e. g., Ergot), which later, under suitable conditions, gives origin to the
spore-bearing body. Some of the Fungi have no higher mode of repro-
duction than that of simple division (fission), although almost all of
them reproduce by means of spores. These spores are borne in various
rilALLOPIIYTA
211
ways (Fig. 591), as to both their minute and conspicuous structures.
In the higher forms, such as tlie mushrooms, tliis ])ocly consists of a stem
bearing a cap or Pileus (Fig. 590, a), wliich bears tlie si)ores under-
neath, on gills, teeth, or some
simihir support (Fig. 591).
The Algae.— The Algae
are almost without rei)re-
sentation in the materia
medica, although they yield
important food supplies,
especially in Japan. P^ven
Chondrus, the most impor-
tant member in drug com-
merce, is in reality only a
food, while Fucus acts ratlicr
by inorganics, absorl)ed by
it from the sea-water, than
by any organic princi])lc of
its own.
Fig. 590. Amanita phalloides.
Fig. 591. Showing parts of Mushroom— .4oaric«s
{FsalUola) campestris: A, a section across a number of
gills, h; the hymenophore, /; the lamellae or gills, one of
which is more highly magnified in B, t, the central hyphal
tissue; liy, the /li/mivuiaH, or spore-bearing surface; C,a
portion of gill still more highly magnified, // the hyphae,
q; the basidia upon which the conidia or spores are borne,
s, s', »■" — conidia in different stages. (Sachs.)
The Algae are essentially atiualics, and diU'cr from the Fungi in
possessing chloro})hyll or some similar substance, by which they are
enabled to l)uil(l up their food sui)i)lics from inorganic matter.
The last nicnti()iu>d plant is among the liighcst of this class. The
thallus, or ])lant body (Fig. 592), coiisi.Ntiiig of a loose aggregation of
single cells, has a well-developed foot, tl.e di-k. by which it clings to
212
GENERAL CHARACTERS OF CRYPTOGAMS
rocks. The stem is branching and bears the reproductive bodies (Fig.
593) at the ends of its branches.
Fig. 592. Rock Weed, Fucus: A, portion of branch bearing reproductive organs, /; B, an enlarged
section through a reproductive organ, the female conceptacle, showing egg cells, c; the cavity, b;
false parenchymatic tissue, d. (After Thuret.)
LAJ
^^^#^'-
Fig. 593 The sexual organs of Fucus 4, the antheridia, or male organs, a, borne on paraphyses;
B, antherozoids or gametes, /, the oogonium or female organ, og; paraphyses, p; II, the oospores
(oospheres), preparing to be set free; ///, a free oospore, being fertilized; IV, V, young Fucus plants.
THE BRYOl'IlYTA
213
DillVroiit sexes are hoi'iu' on dillci-ciit ])laiits. The t'einale uv\:;\\\
consists of a number of sini])Ie ovaries ((Jogonia) (Fig. 592, c; Fig, 593,
ocj), grouped together in a Conceptacle. Eacli oogonium contains eight
Odsplieres. These oospheres are set free and are fertiHzed by motile
Gametes, tlie Antherozoids, which are produced in conceptacles of
another plant.
The Lichens. — Most systematists now regard the Lichens as belonging
to the Fungi. They may be defined as Fungi parasitic on certain
Algae. In this form of parasitism each plant supplies some indispen-
sable contribution to the other, the relation being therefore called wSym-
l)iosis. ^riie body of the Lichen, more particularly in the larger forms,
is made uj) of the Fungus mycelium (Fig. 595, sh). The thallus may
Fid. 594. Concral viow of several Lichens: A, crustaceous (Graphis); B, a portion of this samelichen
more highly magnifiod, showing apothecia; C, a crustaceous lichen, Pcrtusaria; D, a sub-foliaceous
thallus of Parmdia with numerous spore-bearing bodies, apothecia. (Sachs.)
be large and flat, leathery and leaf-like (foliaceous. Fig. 594, D), or
upright and branching (fruticose), or close-clinging to the bark of
trees, looking like a colored stain on rocks (crustaceous, Fig. 594,^1, O-
Li most cases the spores are born, eight together, in little sacs called
Asci, which are themselves reproduced in variously colored dosed or
open A])()th('cia (Fig. 594, D).
The Bryophyta. — Li this class the cons])icuous generation is the
gametophyte which, in the higher divisions (left hand. Fig. 59(5),
becomes a well-developed plant with stem and leaves. Its male repro-
ductive organs are the Antheridia (Fig. 597, a); its female are the
Archegonia. The efl'ect of reproduction is the j^roduction of an embryo,
which immediately germinates while upon the gametophyte, sending
its foot down into the tissue of the latter, and developing upward into
214
GENERAL CHARACTERS OF CRYPTOGAMS
a sporophyte (Fio:. 596, .9, /, c), wliicli is tlie Capsule. These ripened
spores, in turn, germinate to produce a new gamet()i)hyte which, in its
embryonic state, is called the Protonema. It will be observed that the
A
fA\
Fig. 595. An Ascomycetous Fungus — Peziza —
A, showing section through complete spore-
bearing body — the apothecium; h, tlie hyme-
nium: s, the hyphae, forming false tissue; B,
enlarged section of a portion of above showing
a, b, c, d, e,f, asci, in various sizes and in various
stages of spore development taking place within
them, spores are mature in /, sh, the false paren-
chyma made up of intertwining hyphae.
Fig. 596. Showing the development of sporo-
phyte of moss: St, apex of stem, bearing the
female organs; o, the archegonia; from these,
after fertilization, the young capsules spring,
C, S, V; C, the calyptra; underneath which is
found lid or operculum; /, the capsule; s, the
leafless stem of sporophyte or pedicel. (Frank.)
relative positions of sporophyte and gametophyte are exactly the
reverse of what they are in the flowering plant.
Although the hair-cap moss is somewhat used in medicine, yet
THE PrERIDOPIIYTA
215
iieitlier tlie TTepatics nor Mosses may be considered as worthy of note in
commercial pharmacognosy. In the Mosses, the top of tlie stem or
branch bears a number of bracts or modified leaves, which constitute
the Perichaetium. From amidst these bracts the Pedicel (Fig. 59G, s)
rises from the foot and bears the capsule upon its summit. Through
i^*^^,.
Sli' / .1
^l
Fig. 507 The male organ, antheridium of
mosses (Funaria): A, antheridium, with escaping
antherozoids (o) ; B, a single male element 6, in
mother cell; C, free, with two cilia.
Fig. 598. Lycopodium: S. the oone-like spore-
Wearing leaves; B, an enlarged sporophyll leaf;
h, the blade, and sp, the sporangium which con-
tains the spores.
the center of the ca])sule the Pedicel is continued as the Columella, and
at its summit it is closed in until mature by one or more coverings. By
a special organ, the Peristome, consisting of a number of teeth, it is
l)ossible for the capsule to be closed during wet weather and opened
for the (listrihiitioii of its spores when it is dry.
The Pteridophyta. — All three groups of this division contribute more
or less important articles to the commercial materia mcdica.
Equisetaceae. — In this group again we ha\e, as in {\\v flowering
plant, a gametophyte which is microscopic, although, unlike that of
the flowering plants, it is produced entirely disconnected from the
sporophyte. From it develop hollow-stennned i)lants which are com-
monly known as horse-tails or scouring rushes. The latter name is in
allusion to the large amount of silica produced in their superficial
216 GENERAL CHARACTERS OF CRYPTOGAMS
tissues, on account of which they are frequently used for scouring
purposes. Medicinally they ha^•e' practically no use, although it is
said that poisonous properties exist in one or more of them.
Lycopodlaceae. — The club mosses, like the horse-tails, are said to
contain some poisonous species, but their interest in drug commerce
resides wholly in the use of the spores of some species, inider the name of
Lycopodium or vegetable sulphur. In the species yielding this product
there are two forms of leaves, those upon the fruiting portion differing
materially from those of the main stem (Pig. 598). In this group the
spores are all similar (Homosporous), while in some of the lower groups
they are of two forms (Heterosporous). As in the class last considered,
the gametophyte is microscopic, while the sporophyte is the con-
spicuous generation. Upon the upper surfaces, or in the axils, of the
leaves of the fruiting branch the spore-cases (Fig. 598, sp) are solitary.
In collecting Lycopodium, it is customary to pull off these tops and
allow them to dry thoroughly, whereupon the spores are easily shaken
out.
TJw Filices. — The ferns contribute a number of important articles
to the materia medica, the principal of which is Aspidium, or Male
Fern.
From a pharmacognostical viewpoint, the chief difference between the
ferns and the flowering plants is in the stem-structure. The main stem
is usually under ground, although often aerial and sometimes assuming
the dimensions of a shrub or tree. In the Hawaiian Islands these
trunks furnish timber for "large amd heavy planking. The peculiarity
of the fern-stem is its possession of a number of steles, each having
its own endodermis. As compared with the stem of an ordinary dicotyl-
edon, that of the fern presents the structural appearance of being a
fascicle of stems, bound together by an interstellar tissue. This indica-
tion is borne out by the peculiarities of the structures which fill the
office of the leaves of other plants, and which are known as Fronds.
While thus taking the place of ordinary leaves and appearing to be
such, these are seen, on closer examination, to be the homologues not
of leaves, but of stems, each of them originating from and representing
one of the steles of the compound stem. There is, moreover, no such
division of the stem into phytomers as we see in the flowering plants.
It is not necessary to study the main stem in order to discover the
wide difference between the leaf and the fern frond, for if one but
watches the development and behavior of fronds, especially in certain
groups, as the Gleichenias, he will be struck by the fact that it is, in its
THE I' TEHl DO I' II Y TA
217
real iiaturi'. more like a \ivvvu and (lattoiicd stem than a leaf. These
facts have led many inorplioloyists to look upon the fern-frond as a
structure distinct in kind from the leaf.
In the ferns we again find the gamet()i)hyte small and inconspicu-
ous (Fig. 599), while the sporophyte is the generaffon familiarly known
to us. These sporoj)hytes may he herhs, shrubs, or trees, and many of
them are climbers.
Fig. 599. Organs of reproduction in the ferns: J, //, III (p), prothallium or gamctophyte; a, the
male organ, antheridium in various stages of growth of antherozoids, which in h are sliown free and
provided with cilia; c, oo.spore or egg cell: E, the archegonium — developing into young fern plant — h.
The sporangia may be borne on tlie lower surface of the one form of
frond possessed by a species, or the sporophyll may be entirely different
from the other fronds. In the former case, the sporangia are grouped
in little masses, forming rusty- or dark-colored spots on the surface
which are known as Sori or Fruit-dots. These may be naked, or partly
or wholly covered by the reflex and modified margin of the frond, or by
special bract-like membranes, developed from the surface of the frond.
Such a membrane is called an Indusium. When the sporophyll is of
special form, the modes of arranging, enclosing, or protecting the
sporangia are various. I'pon these characters, and upon those of the
sporangia themselves, is chiefly based the classification of the ferns.
"CHAPTER XIX
'BOTANICAL CLASSIFICATION AND ANALYSIS
Reference was made in our introductory chapter to the object of
Systematic Botany as being the arrangement of plants in a system or
series which should indicate approximately the successive order of
their appearance in existence, that is, of their development, or of their
creation, as commonly expressed. The Cryptogams or flowerless
plants undoubtedly existed first, and from some one or more of their
sub-divisions the flowering plants developed. The former are therefore
regarded as "lower" than the latter, and are treated as the basal or
fundamental division of plants. Similarly, certain of their divisions
occupy the relation of having existed before others and of having given
origin to them, and are therefore regarded as occupying the lower
positions in the cryptogamic series. By determining those relations
for the various sub-divisions, we obtain grounds for arranging all the
cryptogams in a sequence of which it may be said, in general, that the
lower came first to exist and the latter are newer in creation. By apply-
ing the same methods, the Phanerogams are formed into a similar
series.
It must not be understood that these groups occupy an unbroken
serial relation to one another, like the rounds of a ladder. They would
do so had each group given origin to only one other, and had all the
groups maintained their existence, or even left evidences of having
existed, so that their relative positions could be assigned them. Instead
of this, a formerly existing group frequently, probably usually, gave
origin to several new forms, many of which became the starting points
for others, so that the system is more like that of the branching of a
tree than of a series of steps. Furthermore, it has frequently happened
that a recent form has continued in existence, while that from which
it originated has perished and left no record. So great an influence
have those conditions exerted that we have various groups now in exist-
ence, which show no special relationship to any other, and we have to
assign them somewhat arbitrarily to their positions. For thejiliind
similar reasons, our system is at the best faulty and incomplete, and tlilfr
SPECIES 219
nature of tlio case is such tliat it i)r()l)al)ly must always remain so. In
spite, however, of all these imjierfections, steady and great progress has
been and is being made, and this natural system of classification must
be regarded as a most useful attemi)t to indicate just such genetic
relationships as exist among human beings.
The divisions and sub-divisions thus established stand as ft>llows:
Divisions. — Of which there are two, the Cryptogamia and Phanero-
gamia, the latter being now often called Spermatophyta, as the pro-
duction of seeds is regarded as their most important characteristic.
Sub-divisions. — Leaving out of consideration the divisions of the
Cryptogamia, we find the Phanerogamia divided with two sub-divisions,
the Gymnospcrmae and the Angiosperniae, the latter the higher.
Classes. — Leaving out of account the Gymnospermae, the Angio-
spermae are divided into two classes, the Monocotyledons and the
Dicotyledons.
Series. — The Dicotyledons are divided into three series, the Thal-
amiflorae, Disciflorae and Calycifiorae.
Cohorts. — Each of the series named above is divided into a num])er of
Cohorts, or orders. Thus the Thalamiflorae have G cohorts, namely,
Ranales, Parietalcs, Polygalinae, CaryophylUneae, Guttifcrales, and
Mai vales.
Families. — Each cohort consists of a number of Fatnilics, of which
there are about 3{)() among flowering plants, the Ranunculaceae or
Buttercup Eamily and the Compositae or Daisy Eamily being exam})les.
Sub-families and Tribes. — Families, if large or heterogeneous, are
often divided into Tribes, or into Sub-families, the latter then divided
into Tribes. Thus, the Ranunculaceae contain 5, the Compositae 13
tribes.
Genera. — Families, either directly or through their tribes, are divided
into genera, of which the most modern authorities recognize between
8()()() and 9(K)() in all the families of flowering ])lants. The genera are
very irregularly distributed among the families. Thus, the family
Columelliaceae contains but one genus, Coluinellia,\\hi\e the CoDiposiiae
is made up of some SOO of them.
Species. — Genera, either directly or through a number of Sub-genera,
are made u]) of species, of which there are })robal)ly not far from 2r)(),()()()
now described among flowering plants. These are very irregularly
distributed among the genera, many of the latter containing but one
species, while others contain hundreds. Solanuui. pi-obablx' tlic largest
genus, has been credited with as many as 1200 species.
220 BOTANICAL CLASSIFICATION AND ANALYSIS
A species is considered as an nitimate individual kind of plant, like
the Red Maple, the ordinary medicinal Wild Cherry, or the Two-leaved
Pink Ladyslipper.
Varieties. — Varieties frequently exist among the individuals of a
species. It is practically impossible to establish rules for determining
whether two closely related forms are two species or two varieties of
one species, and there is hardly a point upon which our botanists are
more at a disagreement than in estimating these cases. It may be said
that a variety is a form of a species which depends either upon a natural
tendency to vary, or upon modifications brought about by difl'erent
climatic conditions or other environment, but which, in either case, is
not permanently fixed, its descendants being liable under various con-
ditions to reassume the characters of the parent. The characters of a
species are, upon the other hand, supposed to have become permanently
fixed. It may, of course, vary, but there is no special tendency for it
to vary in the direction of the ancestral form more than from it, in a
new direction.
Forms. — Variations which are not at all fixed, and clearly temporary
in their nature, as the occurrence of a white fiower among plants habitu-
ally blue-flowered, give rise to Forms. These are hardly considered
worthy of names.
Botanical Analysis. — This consists in the determination of the botani-
cal ])osition and name, if it have one, of a plant, by comparing it with
published descriptions until that one is found with which it agrees.
To make such comparisons individually, and without system, would
prove interminable among such a vast number of species, and the system
of classification above mentioned is employed to reduce to a minimum
the time and labor required. The process is essentially one of successive
exclusions of the plant under study from more or less extensive divisions
and subdivisions.
By determining that our plant produces flowers and seeds, we exclude
it from the Cryptogamia, approximately half of the vegetable kingdom.
Another similar act excludes either the Angiospermae or Gymnospermae
and another, if it be an Angiosperm, from either the Monocotyledones
or Dicotyledones. As the process continues, it becomes somewhat more
complicated. The first steps may be positively taken by deciding a
single point, but farther on, in determining the family, genus, and
species, groups of characters have to be considered together, and
held in mind at the same time for comparison. This is in general due
to the fact that the characters separating the primary groups are
BOTANICAL ANALYSIS 221
older in time, and tlierei'ore more constant and less inclined to vary,
while those characterizinjj the lesser groups are more recent in their
origin, and nnicli inclined to vary in diflerent individuals. They are,
therefore, less trustworthy and have to be considered in connection
with others. It is for this reason that the most frequented ifl'erences of
opinion concerning classification among botanists relate to genera,
species and varieties.
CHAPTER XX
BOTANICAL NOMENCLATURE
In naming a plant, the object is to apply a name which does not and
cannot be made to apply to any other. A familiar illustration is the
name of the common Red Maple. In scientific circles the name " Red
jNIaple" cannot be regarded as sufficiently exact and definite, because
in different localities it is known as Soft maple, Swamp maple, White
maple, and Early maple; while doubtless different maples are called
"Red" in different localities.
Scientific accuracy, therefore, renders it indispensable that a system
of botanical or scientific names, as distinguishable from the common,
vulgar, or trivial names, shall be employed. The name Acer is, therefore,
applied to the genus to which the maples belong, and this is known
as the generic name of all the species of j\Iaple. One of the rules of
nomenclature requires that no other genus shall bear this name. In
order to distinguish the different species of Acer, each must have,
in addition, its specific name, the Red jNIaple receiving the specific
name of Rubruni. It is, therefore, to be known as the Rubruvi AeeVj
although the Latin form, with the generic name preceding, is employed
thus, Acer ruhrum, the specific name, except in certain cases, beginning
with a small letter. By another rule of nomenclature, only this par-
ticular Acer may be called ruhrum, although this name may be applied to
plants in other genera than Acer. It is clear now that this combination
of generic and specific names yields a complete name, and this is called
the Binomial, which may not be applied to any other plant in the world,
while either its generic or specific name may be.
It often happens that a plant name is for one reason or another
abandoned by some, or most, or even all botanists. It is not then
permitted that it be given to another plant, because it is liable at any
time to be used again in its old application by other botanists, so that
we should then come to have two plants of that name.
In spite of the rules here stated, it frequently does happen, very
frequently has happened in the past, that a botanist, ignorant or care-
less that a certain name has been used, applies it to some other species,
BOTANICAL NOMENCLATURE 223
thus causing a duplication. In such a case the name Acer rnbrum
could not inform us with certainty which species was referred to by the
writer or s])eaker. It might, for example, he an Am- niJn-inn made by
Linne in 1753 or one so named by some one else in ISSO. It is therefore
necessary to add to the plant-name the name of its jnitlior, thus, .leer
rubrum Linne. This necessity for the use of the a.uthor's name is semi-
barbarous, and is a mere monument to the lack of system in plant-
naming which once existed. With the perfect systematizing of nomen-
clature this necessity will pass away. For convenience, it is customary
to abbreviate the name of the author thus, L. for Linne, Reichb. for
Reichenbach, or Benth. for Bentham. The generic name may also
be abbreviated in many cases by writing only its first letter, followed
by a period, thus, A. rubrum L. This of course can only be done when
it is well understood to what genus the writer is referring. For example,
in the above cases, where we have been speaking only of Acers, the
abbreviation "A." can be employed with entire satisfaction.
A name in parentliesis will sometimes be found interposed between
the generic and specific names thus, Acer (Negundo) aceroidcs. This
indicates that the genus consists of two or more sub-genera, the one in
this case being Negundo. It is not customary to indicate the sub-
genus in this way, but a writer often desires for some special reason to
do so.
The name of an author enclosed in parenthesis is often seen standing
between the specific name and that of the author, thus Acer aceroides
(^Nloench) Gray. This means that the botanist named in the paren-
thesis assigned to the plant its specific name, but connected it with
some other genus, the later author, whose name follows the parenthesis,
having transferred it to the present genus, thus creating the present
binominal. In all cases where a plant is thus transferred to a different
genus, it must retain its original specific name, unless the genus to which
it is so transferred already has a species with that name, in which case
a new specific name must be assigned, this necessity being to a^•oid
binomial duplication.
Wlicn the name of the author in parenthesis is not followed by
another, it means that the writer claims that this binomial has never
been printed and that he must henceforward be cited as its author.
We frequently see a trinomial used as the name of a jilant. thus,
Viola tricolor alba, no parenthesis being used for the middle iianic.
This indicates that the species Jlola tricolor sometimes exhii)its a form
possessing white flowers, and that this form is regarded as a variety of
224 BOTANICAL NOMENCLATURE
the species. The name alha is in this case called the varietal name.
Another way of writing it, but which has not the sanction of botanists,
is "Viola tricolor, var. alba."
The use of capitals and italics in printing botanical names is not,
except in special cases, of botanical significance or authority, though
attempts have been made to so treat it. Literature and individual
taste supply the rules for this usage. This statement does not, how-
ever, apply in the case of the initial of the generic name or of the name
of the author.
It has been shown above how two plants may come to have the same
name assigned to them. In even a greater number of instances have
several different names come to be applied to the same plant. The
extent to which this has occurred may be realized from the fact that
more than eight hundred thousand names exist for the two hundred
and fifty thousand known flowering plants, this being an average of
more than three names for each plant. Since only one name can be
recognized for a plant and only one plant for a name, it follows that
all others must be regarded as synonyms and should not be used.
Until a comparatively recent period very autocratic methods have
ruled in the selection and application of names under these circum-
stances. Each country has had but a few, or even but one botanist
who assumed authority, and these have, in most instances, acted
irregularly and inconsistently in selecting and applying their names.
Now, however, most botanists recognize the importance of having some
uniform custom, based upon sound principles, and the attempts in this
direction ^re likely to result in great improvement.
The fuxidamental rule of nomenclature is that the first names, generic,
specific, and binomial, ever given to a plant, beginning with the year
1753, sh?ll be permanent, provided that they do not involve errors.
Such errors may be literary or botanical. Literary errors may consist
in wrong spelling or inflection, or in a composite derivation, part of
the name being taken from the Greek and part from the Latin. Such
errors do not justify the substitution of another name, but only a correc-
tion, with as little change as possible. Botanical errors justifying the
substitution of a new name are numerous and varied. The most
common is the reference of the plant to a wrong genus, as calling a
Ruhus a Rosa. Whoever discovers such a mistake is required to refer
the species to its proper genus, but its specific name must if possible
remain unchanged. The name of the author of the specific name then
goes in parenthesis, as already explained. Not ah changes of this sort
BO TA NIC A L NOMENCLA TURK 225
indicate actual errors. The lines of distinction Ix'twccn two f,fcncra
are often very ari)itrary, the different ()i)inions of different botanists
being apparently equally well founded. One botanist will thus regard
as of one genus plants which another divides among two or more genera.
Another very common error in the past was that of assigning to a
genus a name which had already been applied to another. This, of
course, necessitates a re-naming of the genus, all the specific names
remaining unchanged and their autliors cited in ])arenthesis as already
explained.
Errors in specific names have occurred most frequently through the
re-naming of a species which has already been published under a difierent
name. In such cases, when the error is discovered, the name last given
must fall. A difference of opinion has existed as to whether such a
discarded name should be permitted to be afterward taken up and
applied to a newly discovered plant. If the error in the first use of the
name were beyond question, no harm would result from so doing, but
such is not the case. In numerous cases botanists have disagreed as
to the specific identity of two plants. One regards one of the plants
as a mere accidental or temporary state of the other and discards its
specific name. If, now, the discarded name be applied to some other
species of that genus, there is danger that at any time the original
opinion may be revived concerning the previous application of that
name. This having in the meantime been applied to another si)ecies,
we have the same name applied to two species. For this reason conser-
vative botanists hold that just as a generic name once discarded may
never be given to another genus, so a specific name, once dropped,
may never be applied to any other species in the same genus. ' This
constitutes the important rule often referred to, as in the cxjjression,
"Once a synonym (or homonym) always a synonym."
The whole subject of nomenclature and the rules which have been
formulated for it are very extended and c()mi)licated, but the most
important ])rinciples upon wliicli the rules are based have here been
explained.
15
CHAPTER XXI
THE COLLECTION AND PRESERVATION OF BOTANICAL SPECIMENS
The study of botany cannot be properly pursued without the pres-
ervation of specimens. The mistake is very general of assuming that
such material is required only in case of the making of a permanent
herbarium. It is necessary besides as a temporary expedient in the
thorough study of plants. A plant is not studied until all its parts
have been examined. As the mature fruit is rarely present with the
flower, and as the stem, leaves and underground portions are liable to
present different characters at different seasons, it becomes necessary
to make several collections from the same plant and to preserve them
to be studied together. There is, moreover, a waste of time involved
in using the summer season for dissection and study, when the attention
should be directed to field-work.
Specimens may be preserved in alcohol or in formaldehyde or other
solution, or they may be preserved by drying. The latter method is
usually employed and is the more generally useful, although it possesses
certain disadvantages which will be referred to further on.
Alcoholic specimens are made by simply immersing the material In
alcohol and sealing perfecth'. Very fleshy specimens may require a
change of alcohol after a time. An improvement on this method is to
immerse them in 50 per cent, alcohol for a few days, then transfer them
to 75 per cent, alcohol and later to that of full strength (95 per cent.).
Alcohol is liable to remove coloring matters and many other substances,
as well as to extract the natural water, thus giving to the specimens a
shriveled or wrinkled appearance. The use of a formaldehyde solution
obviates both of these difficulties, even the most delicate colors being
in most cases perfectly preserved. The strength of the solution ranges
from 3 to 9 per cent., ordinary water being employed as a vehicle. In
the case of fleshy fruits and some other substances, it is found necessary
to pour off the first solution and apply a fresh one after a few days, and
this renewal may be called for from time to time as the specimens show
signs of deterioration. Under the very best of conditions, it must be
expected that some changes will occur in the appearance of specimens
preserved in solution, and the same is true of those prepared by drying,
THE RECORD HOOK Til
SO that it hfcomcs necessary to take careful notes re<^ar(]in<;- ])lants at
the time of their collection.
The Record Book.— The record is to include the colle<tion number of
the specimen, which is also to })e attached to the specimen at the same
time, the date, locality, altitude, habitat, habit of the ])lant, color and
any other facts not likely to be readily reco<i;ni/e(l in the dried specimen.
FieU No.
256
O
Bolivian Flora.
! «
: &
: *i
1 1
Bang Collection.
Field No.
i
1 j
Ci
250
G
i
Bolirian Flora.
H-" J
Bang Collection.
! I
O :
:
Field No.
260
o 1"
i
o
Bolivian Flora.
5' Q
^
Bang Collection.
_= ■
a
The l)est form of note-book is one containing lOO pages like that here
figured, a convenient size for which is 4 x 7 inches and printed on \ery
strong and tough paper, such as cartridge-pai)er. The numbers borne
on these pages are to be printed by machine, so as to avoid all pos-
sible form of error. Through the holes in the tags at the bottom of the
page strings are to be tied and the tags are to be firmly attached to the
specimens. When the specimen is studied later there can thus be no
possible question as to the specimen to which the notes refer. When
the specimen is finally mounted in the herbarium, the remainder of the
page should be torn out and glued to the sheet, the tag still remaining
attached to the plant as indisi)utable evidence of identity. With
great care, a similar assurance is i)ossible without these elaborate
provisions.
Besides the notes referred to aboxe, it may Ix- necessary to note the
dioecious character of a plant, in which case that of the other sex must
also be sought. This should be given the same number, followed by
the proper sexual sign or by the letter a or b. If the leaves are not yet
developed when the flowers appear, as is frecjueutly the case with early
228 THE COLLECTION OF BOTANICAL SPECIMENS
spring flowers, an estimate should be made of the time when the leaves
will probably be ready for collection and the number of the plant
entered in an engagement calendar under the pro])er date at which the
place should be again visited. The same thing is true in case the fruit
is not ready at the time of .the collection of the flowers. In these cases
it is best to attach a tag to the living plant at the time of the first
collection to avoid all possibility of confusing two species in the final
complete collections.
Selecting the Specimens. — This matter of representing all parts of the
plant and the same parts at different seasons is of special importance
in case of pharmaceutical studies. Even the winter-buds and the
underground portions in the winter season should be secured. One of the
most important points is to secure the root-leaves of ordinary herbaceous
plants, as well as the peculiar leaves of trees and shrubs which often
grow upon root-suckers or upon young specimens. It is also wise to
cause the germination of seeds and to preserve the seedlings with the
remainder of the specimen. Pharmaceutical specimens moreover should
represent the bark and the wood and these may with profit be taken
separately from root, stem and branch.
Ordinary herbarium specimens, when finally completed, skould
not exceed sixteen inches in extreme length by ten inches in width.
Even specimens of three or four feet in length may be easily reduced
to this size by kinking and folding them at the proper points without
entirely separating any part. Underground port ons, when not too
large, should remain attached. Inconveniently thick portions, such
as tubers or fruits, may be split and one or both parts preser^'ed, or the
centre may be cut out so as to reduce the thickness. In the case of
large specimens, it will frequently be found necessary to remove a
portion of the leaves. This should be very judiciously done, those
retained being left at difi'erent points upon the specimen so as to show
the successive modifications, and portions of the petioles should be
left so as to indicate their position. In case of large plants, such as
shrubs and trees, where only a branch can be preserved, it is impor-
tant to select this branch from a part where growth has been free
and unrestricted and a natural symmetry attained. With each
specimen, a few loose flowers and buds should be preserved for
dissection i)urposes.
Preserving the Specimen. — Specimens thus taken should be at once
transferred to a portfolio carried into the field. Various forms of
portfolios are for sale by botanical supply houses. They may be
PRESERVING THE SPECIMENS 229
made of cardboai'd, wood-ljoard, wooden lattiee work or wire frames, and
they should be earried iu a strong- ])air of strai)s, simihir to the ordinary
shawl-.straj). The portfoHo should contain a number of double sheets
of paper of about 11 x 17 inches. Xothinji; better can be ol)tained than
single i)ages of an ordinary New York daily newsi)aper once folded.
Within this fold the specimen, with tag attached, is to be laid, its leaves
and flowers as straight as can be, one or more of each turned with the
face, and others with the backs uppermost. While being carried in the
portfolio, they should be subjected to strong pressure to i)revent
wrinkling, and none of the parts must be allowed to project beyond the
edges of the paper.
Within twenty-four, and nnich better within six or eight hours of
the time of collection, the folds, with specimens contained, are to be
transferred to the dryers. At this time, each specimen should be gone
over, its leaves and flowers perfectly straightened out and arranged
in the position desired when dry. It is often desirable to introduce
several thicknesses of bibulous paper inside of the specimen sheets, so
as to make the entire thickness correspond with that of any excessively
thick portion of the specimen, such as a large root, fruit or tuber.
The drjers are to consist of some thick bibulous paper. When little
collecting is to be done, blotting paper is desirable, but when collecting is
upon an extensive scale, this is far too expensive and })erishable. Various
forms of dryers of excellent quality are for sale by the botanical supply
houses, but, in drying on a large scale, it has been found possible to
effect considerable saving by improvising them out of some suitable
material. The author has found the best method to be to obtain rolls
of thick, gray house-sheathing paper, 30 inches in length. This may
then be cut into 12-inch lengths, and folded to a size of 12 x IS inches.
When the amount of the material drying is large, it is better cut in
24-inch lengths and folded to 24 x 18 inches. Dryers of this size will
then accommodate two specimen sheets lying side by side. There are
so many varieties and qualities of house-sheathing on the market, that
careful selection is necessary. For plant-dryers it should be free from
mineral and coloring matters, tar and sizing, and its quality should be
tested by its ability to take uj) moisture readily. As a general state-
ment,* it may be said that that grade ordinarily denominated "poor" by
builders should be sought. The numl)er of dryers between two layers
of s])ecimens should be determined by the auKHUit of herbage possessed
by the latter, by the condition of the weather and climate, the facilities
for frecjuent changes of dryers and other similar conditions. In hot,
230 THE COLLECTION OF BOTANICAL SPECIMENS
dry weather only one folded dryer is required for ordinary herbaceous
plants of temperate climates, provided the dryers are changed twice
or even thrice a day. In bad weather, or with thick, water-laden speci-
mens, or when the plants must remain more than twenty-four hours in
the dryers without change,- four folded dryers are required. By using
a large number of dryers in the best of weather, it is frequently possible
to dry ordinary specimens with but one change of dryers ; or even without
change, to secure specimens of the first quality.
Powerful pressure should next be applied. Weights, screws or levers
may be employed for this purpose, but no other method is equal to
the use of straps. These should be made of the heaviest and best
leather obtainable, should be li or 1^ inches in wddth and provided
with a large strong buckle, the holes not more than two inches apart
and punched to within two feet of the buckle. The length of the straps
should be proportional to the size of the bundle drying. For extensive
collecting, straps of 8 feet are required. The straps should be laid only
a few inches apart and the bundle laid upon them so that the buckle
barely projects from under the edge. The straps should be drawn
firmly into place without drawing the buckles from their place. The
operator now stands upon the bundle and stamps it firmly at all points,
so that no parts of the specimens are left without a firm application
of the dryers. The straps are then drawn as tightly as possible and
secured. A strong man can thus secure pressure of 500 or 600 pounds,
all of which is required for a pile of dryers two feet or more in height.
Even then it will be found, after the lapse of two or three hours, that
the pressure has become almost completely relaxed, owing to the wilting
and shrinking of the specimens, and the straps must be tightened.
The pile should now be stood upon the end on a dry stone or wooden
support, a pole frame being best. The flat side should be exposed to the
sun, or quite as good, to the heat of the kitchen range. When possible,
the dryers should be changed twice a day for the first day or two. The
dryers into which the sheets are to be transferred should be perfectly dry
and if possible hot from the sun. When it is not possible to expose them
to the sun just previous to making a change in the morning, they should
be wrapped tightly in a rubber cloth when brought in from the sunshine
of the previous afternoon, as dryers not thus protected will absorb a
considerable amount of moisture during the night. It is to be con-
sidered that the first hour in perfectly dry, hot dryers contributes quite
as much to the beauty of the specimens as the succeeding five hours.
In making the change, the specimen sheets are to be transferred to
MOUNTING THE SPECIMENS ^31
the fresh drj'ers without opening. Under the ahove treatment, in hot
and very dry weather, most specimens will he dried i)erf'eetly in ironi
three to four days. Upon the tahlelands of Mexico and similar localities
only half of this time is required. Many plants, such as orchids or
cactuses, may require all summer for drying and are even frequently
worn out in the ])rocess of changing before they become dry. Such
plants may be dipped for an instant in boiling water l)efore being dried.
This process, while it greatly expedites drying, is apt to make the
specimen turn black.
Great judgment is required to avoid regarding a specimen as dry
before it really is so. The test is to see that any part will snap off in
attempting to bend it. Even after the specimens are perfectly dry they
should not be sealed up at once, as they are liable to undergo a sweating
process during the succeeding day or two. They should be tied tightly
in bundles and these bundles exposed to the sun for an hour or two on
several successive days, after which they may be sealed up, a good
method being to wrap them tightly in waxed paper, this protected by
hea\ier ])a])er, for transportation through a moist climate.
Poisoning the Specimen. — ^^arious methods have been resorted to
for poisoning specimens so as to make them proof against the attacks
of the small insects which infest the herbarium, but in no case have the
results proved permanent. Arsenical and mercural solutions have been
most employed. Upon the whole, a saturated alcoholic solution of
corrosive sublimate is the most satisfactory poisoning agent. Theo-
retically, the corrosive sublimate soon becomes converted into calomel,
but in practice its effects, if it be thoroughly applied, last for a great
nian.\- years. It may be poured upon the specimen, applied with a brush,
hea\ ily sprayed from an atomizer, or the specimen dipped into it. It
is to be treated as a very dangerous poison, not only internally, but
highly irritating to eyes, nose, and lungs and capable of poisoning by
inhalation of the spray.
When insects are found attacking mounted si)ecimens, the latter
should be enclosed in a tight case and subjected for some hours to the
vai)or of carbon disuli)hide.
Mounting the Specimens. — For permanent mounting in the herbarium,
sheets of standard size (Kiixllf inches) should be used and the
l)ai)er should be white and very lieaAy. ^Fuch ])aper now made of
wood-pulj) (piickly becomes yellow or brown, and scrupulous care to
avoid this quality should be taken. The specimens are to be secured
by the use of white glue applied over the entire surface and the stems
232 THE COLLECTION OF BOTANICAL SPECIMENS
and branchlets should also be strapped down with strips of gummed
linen. Before attaching a specimen to the sheet, it should be carefully
examined to see that it exhibits both surfaces of the leaves, as well as
both the inner and outer surfaces of the flowers. Finally, an appropriate
label is to be gummed to a convenient part of the sheet, preferably to
the lower right-hand corner.
Wood specimens and other parts which cannot be attached to the
sheets may be preserved in suitable boxes or cabinets, according to
the taste and means of the collector. In all such cases, careful reference
should be made upon the label of each part of a specimen to the existence
of the other parts elsewhere.
Collecting Specimens for Immediate Examination in the Fresh State. —
For this purpose, various forms of tin case, commonly known as vascu-
lums, are provided. In these cases, specimens placed without free
access of air and light and without the addition of anything more than
their natural moisture, may be preserved perfectly for many days. In
the absence of proper vasculum, any tin pail or tin })ox with a tightly
fitting cover may be used. The author has found it very convenient
to carry with him a square yard of thin rubber cloth, which may be
folded tightly and carried in the pocket without any inconvenience,
and used when occasion requires.
INDEX
Numbers in parenthesis indicate figure numbers; outside of parenthesis, pages.
Abortion (38), 38
of septa (230), 106
of theca, 68
Abruptly acuminate (508, etc.), 183
Absinthium, al<;ene of (76)
Absorbing roots, 160
Acacia leaf (563)
phyllode (562)
Acaulescent, 164
Accessory fruit, 103
parts, 103
Accrescent, 61
parts, 103
Accumbent cotyledons (413), 125
Aceroso leaf (492), 179
Achenium (74-80, 342), 121
Achillaea leaf (556)
Achlamydcous, and symbol for, 33
ovules, 69
Aconite flower (108)
Acorus inflorescence (586)
rhizome (452)
seed (382)
Acropetal anthotaxy (582, etc.), 201
Active period in flowers, 93
Aculeate stem (436), 165
Acuminate (511), 182
Acute, 183
Acyclic flowers, 43
Adelphism, 66
Adenium flower (55)
Adherent calyx (56), 44
Adhesion (54-57), 43, 51
Adnate anther (126), 62
disk (253, 266), 73
leaf (477), 176
stii)ulcs, 174
Adnation (54-57), 43
Adonis flower (17)
Adventitious bud, 169
roots, 160
Aerial roots, 160
stems, 162
Aeschynomene fruit (351), 124
Aesculus leaf (547)
Aestivation (120-125), 59
Aeterio (304-305), 126
Affinities, 19
Agarics, 210
Agglutination, 43
Aggregate fruit, 105
Agricultural botany, its departments, 19
Agrimonia leaf (557)
Agrimony leaf (557)
Agrostology, 19
Ailanthus leaf (508)
Akebia seed (394)
Akene (74-80, 344), 121
Ala (110), 69
Albumin, 128, 132
Albuminous seeds, 128
Alburnum, 144
Alchemilla ovary (179)
Alder inflorescence (15)
Algae, 211
Allophylus disk (261)
Alnus inflorescence (15)
I Aloe stamen (168)
Alternate leaves (571), 196
Alternation of generations, in crypto-
gams, 207
of position, law of, 41
Ambrosia root (439)
Anient (8, 11, 15), 202
Ampelopsis disk (459), 166
Amphitroi)ous, 81
Amplexicaul leaf (479), 176
Analogies, 19
Analogues, 19
Analysis of flower, chai)ter on, 86
Anatomy defined, 17
gross and mimite, 18
AnatrojKJUs ovules (242), 81
Androecium, chapter on, 62
Anemophilous flowers, 90
cross-pollination in, 90
Angiospermae, 219
Angiospermous gynaecia, 70
Angularly ovate, 181
Annual leaves, 175
rings, 144
roots, 158
stems, 161
Annular rhizomes, 164
stigma (210-215), 74
Antennaria leaf (503)
Anteposition, 42
Anterior side of flower, 41
234
INDEX
Anther (12), 31
attachment of (126-133), 62
construction of, 62
cross-section of (14)
dehiscence of, 65
foi'ms of, 62, 64
Antheridia, 213
Antheridiuin of moss, 213
Anthcrozoids, 100, 209
Anthocarp, 105
Anthodium (343, 587), 122, 203
Anthology, 19
chapter on, 23
Anthophore (246), 82
Anthotaxy, chapter on (576-589), 199
Antidromy, 198
Ants Hving in inflated leaf (568), 195
Apetalous, 33
Apex of leaf for cUmbing (567), 194
forms of (506-515), 182
Apical placentae (235, 237), 77
Apiculate (517), 183
Apocarpous fruit, 105
pistil (219, etc.), 70
Apocynaceae, stigmas in (210, etc.)
Apothecia, 213
Apparatus for dissecting, 86
Appendages to androecium, 67
perigone, 57
seed (384, etc.), 131
stigma, 74
Apple (308), 119
Appressed teeth (531), 187
Arborescent stem, 165
Archegonium, 213
of moss (601), 213
Arctostaphylos anther (145)
Argenteous, 177
Aril, false, 129
true, 129
Arillode (381), 129
Arillus (375), 129
Arista (78), 58
Aristolochia flower (106)
Arnica, akene of (79)
Asarum anther (170)
leaf (495)
Ascending anthotaxy (582, etc.), 201
ovule (238), 78
radicle, 133
stem, 165
Asci, 213
Asclepias flower (150, 154)
fruit (349)
inflorescence (579)
poHination in (276)
poUinium (135)
Ash-fruit (339)
Asparagus stem (457), 167
Aspidium, 216
A.ssimilation, 17
Aster leaf (521)
Novae-angliae leaf (479)
Astragalus, ovary of (220)
Astronium ovary (178)
Asymmetry in androecium, 67
Atrojwus ovule (241), 81
Attachment of anther (126-133)
transportation of fruit (297, etc.),
109
Attenuate apex, 183
Attracting insects, provisions for, 91
Auricle (113, 153), 57
Auriculate (521), 184
Author-name, 223
Awl-shaped (499)
Awn (78), 58
Awns (295)
Axil of leaf (1)
Axile embryo (402, 403), 133
placentae (221, etc.), 76
Axillary placentae (221, etc.), 76, 77
Ayenia flower (90)
B
Bacteria, 210
Barbarea leaf (559)
Bark, color markings of, 152
defined, 150
fracture of, 151
importance in pharmacognosy, 150
inner surface, 152
layers of the, 150
nature of, 150
outer surface of, 151
ridges and furrows in (426), 152
section markings of, 151
wrinkled (425), 152
Barks, how to study, 150
Basal placentae (331), 77
style (179)
Base of leaf, forms of (516-523), 183
relation to petiole, 176
relation to plant stem (477-483), 176
Basinerved (528), 186
Basipetal anthotaxy, 200
Bast bundles of root, 142
fibers, 142
Bean, ovary of (219)
seed (395)
Beech nut (346)
Befladonna fruit (310)
Berberis, metamorphosis in (61)
Berry (281-310, etc.), 118
Bertholetia fruit (324)
Betula leaf (498)
Bicollateral bundle, 147
Bicuculla flower (27)
inflorescence (580)
Bidens fruit (300)
Biennial roots, 158
stems, 161
Bifurcating branching (435), 156
liijugate, 192
]iiiai)iatc corolla (111), 56
Binomial, 222
Biology defined, 17
Bi-pinnate (563), 192
INDEX
235
Bird-foot \iolct loaf (553)
Biternate (552), 192
Blackberry (305)
Black walnut fruit (345)
Bladder-wrack, 211
Bladdery inflated leaf (564)
Blunt (515), 1S3
Body of ovule (241, etc.)
Bonibax style (183)
Boneset leaf (476)
Borage, ovary (176)
Borago torus (250)
Bork, 140
Botanical analvsis, nature and method
of, 218
chapter on, 218
classification, chapter on, 218
Botany defined, 18
Botryosc anthotaxy, 202
Brace roots, 160
Bracts, 35, 195
Branches, abnormal position of, 154
of root, origin of, 153
of stem, arrangement of, 153
origin of, 153
Branching, diagram explaining (42)
Brazil nut fruit (324)
Brunnichia ovules (240)
Bryophyta, 213
Bud bulbs (464), 168
scales, modified leaves (7, etc.), 27
the (1, 4)
Buds, 157
classified, 169
wanting from some leaf-axils, 153
Bulb, axillary (464)
Bulbs (461-465), 161, 168
terminal (464)
Bullate (484), 178
Bundles, completion of, in root, 143
development of secondary, 143
Burdock fruit (301)
Buttercup akene (344)
leaf (540)
petal and nectary of (()3)
Cactus fruit (281)
Caducous, 61
Caju, pulp of (306)
Calabar bean (371)
Calamus inflorescence (586)
rhizome (452)
Calcar (65), 58
Calcaria, 69
Calesium fruit (279), 96
Calisaya bark, mature (427)
young (425)
Callirriioe bud (21)
flower (22)
the, 32
Callus (2), 25
Calyciilorae, 219
Calyptra, the (87-88), 52
Calyx circle, the double, 30
lobes, 32, 53
the, 32
Cambium circle (422), 143
cvlindor, 143
<l('vel()i)ment (422), 143
Campanulate (93), 54
Camponiancsia, embryo (400)
Campyluspcrinous (338), 121
Cami)vlotropous ovule (244), 81
Cancellate (485), 178
Cancscciit, 178
Capillary leaf, 179
style (190)
Capitahzation, 224
Capitate stigma (196), 74
Capitulum (578), 202
Capsicum, 118
Capsule (318-328), 125
of moss (599), 214
Cardamine (354)
Cardiosi^ermum (294)
seed (370)
Carina (110)
Carinate, 64
Carnivorous leaves (560, 561), 192
Carnose, 116
Carpel, 31
reverted to leaf (19)
Carpels, terminology for number of, 74
Carpology, 19
chapter on, 102
Carpophore (245, 247), 82, 120
Carrot fruit (288)
Caruncle (380, 382), 131
Caryophyllaceous flower (72), 57
Caryopsis (348), 123
Cashew, jiulp of (306)
Cassia anther (143)
fistula, 124
Castalia, metamorphosis in (62)
Castanea fruit (284)
leaf (524)
Castor-oil seed (380)
Catkin (8, 11, 15), 202
Cauda (115), 58
Cautlate anther (133)
Caulicle {ca in Figs. 400, etc.), 132
Ceiba anther (128)
Cell walls, 32
Cells, 32
development of new, 106
of fruit, abortion of, 106
Cellular dcvel()i)m(Mit, 138
Central cvlinder of root, 141
of stem, 146
placentae (221, etc.), 76
Centric embryo (402, 403), 133
placentae, 77
Centrifugal inflorescence (584) 200
radicle, 133
Centripetal anthotaxy (577), 201
radicle, 133
Cei)halanthus inflorescence (578)
236
INDEX
Cerastium fruit (318)
Cercis leaf (528)
Chaetostoina stamen (155)
Chalaza (241, etc.), 80
Chambers (223), 76
Channelled petiole, 175
venation, 178
Checkerberry (303)
Chekan leaf (500)
Cherry flower (58)
Chestnut burr (284)
Chimaphila style (184)
Chondrus, 211
Choripetalous, 53
Chorisepalous, 53
Chorisis, 38
diagram explaining (42)
Ciliate (475), 178
Cimicifuga rhizome (448)
Cinchona, false, fruit of (323)
fruit (322)
seed (387)
Cineraria, pappus of (S3)
Cinereous, 177
Circinate, 60
inflorescence, 200
Circular anther (134)
Circumscissile dehiscence (320, 325, 326),
115
Cirrhiferous stem (431), 165
Cirrhose, 165
Chestnut leaf (524)
Cladoidia (457, 460), 166
Cladophylla (457, 460), 166
Clasping leaf, 175, 176
Classification of cryptogams, 210
Clavate, 64
style (182)
Claw (18), 33
Cleft (539), 188
perigone (92), 53
Cleistogamy, 96
Clematis bud (122)
leaf (569)
Climbing stem, 165
Close pollination, 90
sheath (465, B), 170
Closed collateral bundle, 149
Club moss (598), 215
Coalescence, 43
Coated bulb (462), 168
Coats of ovule (241, etc.), 79
Coccus (330, 334), 120
Cochlea (353), 124
Coelospermous (337), 121
Coffee flower (101)
Cohesion, 43
in androecium, 66
in perigone, 52
Cohorts, 219
Collateral ovules (219), 78
Collection of plants, chapter on, 226
Collective fruit, 105
Collinsonia leaf (494)
Colocynth flower (56)
Color in attracting insects, 92
Columella in mosses, 215
Column, 46
Commissure, 120
Complanate, 64
Complete flower, 33
Comi)lex inflorescence, 203
Compositae, pappus of (74-83)
Compound bulb, 168
inflorescence, 203
leaf (548, 554), 189
pistil (218, etc.), 70
Concentric bundle, 149
Conceptacle of algae (592), 213
Conducting tissue of style, 99
Confluent sutures (131, 132), 66
Conical style (181)
Connate-perfoliate (476), 176
Connation, 43
Connective (14), 31
modifications of (155-164), 68
Connivent anthers (92), 66
Consolidated stems (458, 460), 167
Constriction of perigone (100)
Continuous leaf base (482)
Contracted campanulate (95)
Convallaria anther (141)
leaf (526)
rhizome (447)
Convolute (120), 60
Coptis, petal and nectary of (64), 47
Coriaceous leaf, 177
Corm (463), 168
Corn-seed (369)
Cornu, 58
Corolla, 32
as a fruit wing (290)
lobes, 32, 53
Corona (116, 117, 150), 58
Corrugated, 60-
Cortex of stem, 145
Corymb (577), 202
Costae (527), 184
Costate, 64
Costinerved (529), 186
Cotyledons (cot. Figs. 400, etc.), 133
Coussarea disk (254)
Crataegus inflorescence (577)
Crateriform (103), 55
Creeping stem (445), 165
Cremocarp (247, 288), 120
Crenate (530), 187
Crenulate, 187
Cribrose tissue, 142
Cristate, 56
Cross-polhnation, 90
beneficial, 90
Crowded ovules (232), 78
Crown (116, 117, 150), 165
Cruciferous flower, 57
Crumpled, 60
Cryptogamic botan}^ 19
Cryptogams, alternation of generations
in, 207
chapter on, 207
INDEX
237
CryptoKams, chissifiration, 210
comparison with pli;uuM-ot!;ain.s, 207
general characters of, 207
reproduction of, 209
the plant body in, 207
vegetation of, 209
Cucullate (lOS), 56
Cuneate (518), 1S4
Cupulato stifiina (200), 74
Curcuma (444)
Curvincrveil, 1S6
Cuspidate, 183
Cyclanthora anther (134)
Cycle of leaves, 196
Cyclic flowers, 43
Cylindraceous (29, 99), 54
Cylindrical, 54
Cyme (584), 200, 202
Cymose inflorescence (584), 200
Cymule, 201
Cynocrambe embryo (402)
Cyperaceae (588), 206
Cypripedium flower (112)
Cypsela (74-80), 122
Dalibarda loaf (530)
Danais seed (3S6)
Dandelion floret (41, 104)
leaf (558)
Datura fruit (282)
leaf (523)
ovary of (221, 223)
seed (379)
Deciduous, 61
Declined corolla (107)
Decompound, 190
Decumbent stem, 165
Decussate (573), 196
Defence in fruit, 107
Definite anthotaxy (576), 200
Deiiisce, 114
Dehiscence by pores (143, 328, etc.), 66,
116
forms of, 113
incomplete (318, etc.), 115
mechanism of, 115
of anther, 65
of fruit (315. etc.), 113
Dehiscent fruits, 113
Dehi.scing, 114
Deliquescent stem, 164
Delphinium, petal and nectary of (65),
47
Deltoid (49S\ 181
Dentate (n.'A), 1S7
Denticulate, 187
Departments of botanv, 18
Dermatogon (420), 139
structures from, 139
Descending anthotaxy, 200
radicle, 133
Descent of pollen tube (278), 100
Descriptive botany, 19
Determinate anthotaxy (576), 199
stems, 161
Dextrorse (125), 60
Diadelphous (146), 66
Diandrous, 62
Dianthus (18)
Dicldamydeous ovules, 80
Dichogamy, 94,
DichotoiDovis branching, 156
l)ir()tvl(>(ions (416, etc.), 133
DidviKimous (151), 67
Digitalis leaf (516)
Digitateiy veined leaf (527, 528), 186
Dimerous flower (27), 38
Dimorphism (273, 274), 96
Dinemandra flower (66)
Diodia stipules (474)
Dioecious flowers, 30
Dioeciously polygamous, 30
Dionacaleaf (561)
Diospyros fruit (280)
Dipteryx, 124
embrvo (405)
Direction'of ovules (233, etc.), 78
Disciflorao, 219
Discoid, 204
Disk flowers, 204
of anthodium (587, c)
the (260-266), 83
Dissection of flower, chapter on, 86
Dissemination by edible seed-coat. 129
by fixation, 129
by wind, 129
provisions for, 113
through seed, 129
Distinct i)arts, 44
Diurnal flowers, 93
Divergence of leaves, 197
of ovules, 77
Divid(Hl leaf (540, 559), 188
Divisions anil subdivisions of plants, 219
Dorsal awns (172)
dehi.scence (136), 65
spur (114)
Dorsifixed anther (127, 129)
Doubly serrate (531)
Dried specimens, how to dissect, 89
Drosera leaf (491)
Drupe (333), 118
Drupelet (305, a), 119
Drvmicarpus ovule (237)
Ducts, 142
Duplication, 38
Duramen, 144
Duration of leaves, 175
of perigone, 61
E
l"]c(i:\TUi(ALLY peltate (483)
Eccentric embryo (407), 133
])lacentae, 77
Echites flower (100, 125)
238
INDEX
Edible pericarp for transportation (303,
etc.), 109
pericarp not from flower, 109
I)()rtion of fruits, origin of, 110
s('{>cls, protection to, 109
P^ichornia leaf (5G4)
Elateriuin, dissemination of (314)
fruit (314)
Eleutheropetalous, 53
Eleutherosepalous, 53
Eleutherous parts, 44
Elliptical (488, 489), 179
Elm fruit (287), 98, 121
Elongation of internodes of torus (248,
etc.)
Emarginate leaf (509), 182
Embryo, development of (364-368), 127
132, 136
forms of, 134
nourishment of, 128
parts of, 132
position of, 133
protection to, 129
requirements of, 127
Emergences (148), 156
Empirical formulae, 41
Enation (63), 47
Endocarp, 105
Endoderm, 140
Endophloeum, 150
Endopleura, 129
Endosperm, 127
Entomophilous flowers, 90
cross pollination in, 91
Epicalyx (16, 21-24), 34
Epicarp, 105
Epicotyl, 138
Epidermis (422), 139
of stem, 145
Epigynous (56), 44
disk (254), 73
Epigyny (56), 44
apparent or false (59, 60)
Epilobium seed (384)
Equally pinnate (554), 192
Equisetaceae, 215
Equitant leaves, 176
Erect ovules (233), 78
Ergot, 210
Erigeron, akene of (80)
Eriosphaera, pappus of (82)
Erodium (245)
Essential organs, 32
protection for, 32
Etiolated leaf, 193
Eucalyptus bud (87)
leaf (504)
fruit (319)
Eucharidium seed (383)
Euonymus, 131
ovule (236)
Eupatorium anther (169)
Even pinnate (554), 192
Evergreen leaves, 175
plants, 175
Exaggeration of growth, 49
Exalbumiiious seeds, 128 ,
Excurrciit stem, 164
Exine, 99
Exocarp, 105
Exodermis, 140
Exo])lil()eum, 1.50
Ex()j)lcuni, 129
Exsert or exserted, 69
Exstipulate leaves, 174
Extine, 99
Extrorse attachment, 64
dehiscence, 65
Fagus fruit (346)
Falcate leaf (504), 182
False septa (220), 76
Families of plants, 219
Fascicle of flowers, 202
Fascicled leaves, 198
roots, 160
Female flower (9), 29
gametophyte (277), 99
Ferns, 216
oospore (602), 216
Fertilization, 90, 98
in cryptogams, 209
Fibers, 142
Fibrous roots (446), 160
Fibro-vascular bundles of roots, 142
tissue not from periblem, 139
Fig fruit (362)
pulp of (311)
Filament (12), 31
forms of, 64 '
Fihces, 216
Filiform leaf (491), 179
Fission, 210
Fissured corolla (96)
Fistulous stems, 167
Fixation of seed, 129
Fixing roots, 160
Flabellately nerved (527), 186
Flax ovary (224)
Fleshy leaf, 177
' roots, 160
Flexuous branching (433), 155
Floating leaves, 195
Floral envelopes, 33
leaves, 195
Florets, 204
Flower, a modified branch (9, etc., 20), 28
cluster, a modified branch (8, etc.),
27
clusters (576-589), 199
dissection and analysis of, 86
explained and defined, 28, 34
general nature of, 23
some imperfect, 29
Flowerless plants, 207
Follicle (349), 123
INDEX
239
Foramen of ovule, 79
Forms, 220
Fornicate corolla (119), 58
iM.vcolate, 204
Frankcnia embryo (403)
Krasera petal (07)
Fraximis (513)
Free central placenta (230)
parts (47)
Frond, 21G
of ferns, 216
Frondosc stem (456), 167
Fructification defined, 102
parts useful in, 103
parts useless in, 103
results of, 102
Fruit and frynaecium, relations between,
104
classification, chapter on, 116
key to, 116
principles of, 116
defense in, 107
function and structure of, cliaptcr
on, 102
structviral and pliysioloj^ical senses
of, 104
transportation by water, 107
miscellaneous. 111
prevention of (313), 111
Fruits, fixation after transportation,
112
kinds of (279-363)
one-seeded (286, etc.)
table of classes, 116
Fruit-wings, mor])hology of, 108
Fruticose stem, 165
P'ueus (592, 593), 211
sexual organs of (593)
Fugacious, 61
P^unctions, 17
Fungi, 210
Funiculus (241, etc.), 79
Funnel-shaped (97), 54
Fusiform (442), 160
Galbalus (359), 126
Galeate (108), 56
(!all cone (5)
(Jalopina style (187)
Gametes of Fucus (592)
Gametophyte, female (277), 99
in cryptogams, 207
male (278), 100
of moss (599)
Gamocarpous pistil (218), 70
Gamopetalous, 53
Gamoscpalous, 53
(Jaultheria leaf (532)
Gemma, 157, 209
(i(MiiMKiti()ii, 209
Genera, 219
Genera of plants, number of, 219
Generic name, 222
Geranium, diagram of fiower (43)
flower (30)
leaf (546)
Germination, conditions for, 137
figures of (416-419)
nature of, 137
of microspore (278), 99
Gesncria rhizome and roots (446)
Geum fruit (302)
Gibbous corolla (107), 56
Glabrous, 177
Gladiolus conn (463), 168
Glands (66-70), 47, 122
petiolar, 175
Glans (345)
Glaucous, 177
Gl(>ditschia leaflet (554)
Cileichenia, 216
Gleof-apsa (590)
CJlol)ose, 54
Globular, 54
Glomerule, 202
Glumaceae (588, 589), 205
Glumes (588, 589), 205, 206
Glycyrrhiza (146)
Gonophore (249), 82
Gooseberry leaf (539)
Grafting, 25
Grain (348), 123
Gramineae (589), 205
Graminology, 19
Grape, branching in (431)
position and origin of fruit (432)
Grass, flower of (267)
leaf (465 A)
inflorescence (589)
like inflorescences (588)
Gratiola stamen (167)
Green rose, 46
Gregarious plants, 91
Grindelia, akene of (78)
Gross anatomy, 18
Ground-tissue of stele, 141
Guaiacum ovule (235)
Guarea (147)
Guttiferales, 219
Gynmospermae, 219
Gymnospermous gynaeciiuii, 70
ovule, 98
pistil (174, 175), 70
Gymnosperms, germination of (406 ~)
Gynaecium and fruit, relation between,
104
chapter on, 70
composition of, 29
method of examining, 71
symbols and fornuilae for structure
of, 29
Gynandrous (54)
Gynandry (54, 55), 46
Gynobase (250), 82
Gynocardia embrvo (401)
Gynophore (249, 252), 82
240
INDEX
Halberd shapod (522), 1S4
Hamamelis leaf (505, 536)
Hanetio seed (375)
Hastate (522), 184
Haustoria, 160
Head of flowers (578), 202
Heart-wood, 144
Helianthemum style (182)
Heliocharis seed (396)
style (188)
Henbane fruit (363)
seed (377)
Hepatica, flower (23, 24)
leaf (545)
Hepaticae, 210
Herbaceous leaf, 177
Herbs, 161
Hermaphrodite flowers, 31
Hesperidium (329), 118
Heterochromous, 204
Heterogamous, 204
Heterosporous ferns, 216
Hexaptera (356)
Hibiscus bud (121)
Hilum (370, 371), 80, 129
Hippocratea disk (263)
Hippurus flower (25, 26)
Hirsute, 178
Hispid, 178
Histology defined, 18
Homochromous, 204
Homogamous, 204
Homologies, 19
Homologues,,19
Homonym, 225
Homosporeae, ferns, 216
Homosporous ferns, 216
Honey-locust leaflet (554)
Hop-fruit (292, 361)
Horizontal anther (129), 63
ovules (234), 78
radicle, 133
Horn (150), 58
Horse chestnut leaf (547)
Horse-tails, 215
Horticulture, 19
Houstonia flower (273, 274)
Hypanthium, 45
Hypericum seed (374)
Hypocotyl, 138
Hypocrateriform (101, etc.), 54
Hypocraterimorphous (101, etc.), 54
Hypoderm (422), 140
Hypogynous (47), 46
Hypogyny (47), 46
Hyoscyamus anther, 136
fruit (362)
seed (377)
Illipe, flower of (44)
Imbricate (123, etc.), 60
Iinpari-pinnate (555), 192
Inipcrfcction, degrees of, 31
Inipres.'^ed venation, 178
Inci.sed (540, 546), 189
Incumbent cotyledons (412), 135
anther (127), 63
Incurved teeth, 187
Indefinite numljer of parts, 40
Indehisccnt fruits, 113
Indeterminate anthotaxy (582, etc.), 201
stem, 161
Indumentum, 177
Induphcate (122), 59
Indusium, 217
Inequilateral leaf (505)
base (521, 523), 181
Inferior ovary (56), 45
Inflorescence leaves, 204
Inflore.scences (576-589), 199
Infundibular (97), 54
Inga, 123
Innate anther (130), 63
Inner lip (111)
Insect visits, 94, 97
Internode (1)
Internodes, growth of, 153
Interpetiolar stipules (474), 174
Interruptedly pinnate (557), 192
Intine, 99
Introrse attachment, 64
dehiscence, 65
stigmas (191), 73
Intruded leaf base (519), 184
Involucre (587, a), 205
defence in fruiting (284), 107
Involute, 60
Ipomoea (91)
bud (120)
Iris fruit (315)
rhizome (451)
Irregular disk (261)
suppression, 39
Irregularity, antero-posterior, charac-
terizes development, 43
causes of, 43
Isomerous, 37
Jaborandi leaf (525)
Jalap, roots of (437)
Jeffersonia fruit (327)
Jugae, 192
Juniper fruit (359)
Jussiaea fruit (321)
Kalmia flower (103)
Keel (110), 57
Kefir grains, 210
Kelp, 211
ISDKX
241
Lahiatae, "jG
fruit of (334)
Laciniate (540), 189
Ladenbergia fruit (323)
Lamina, 2(3
of petal (18)
Laminar stigmas (203-20")), 74
Lanceolate (496), 181
Lance-ovate (497), 189
Lasioi)Ogoii, i)ai)pus of (81)
Latent 1)U(1, lt)9
Lateral chorisis, 40
primaries, 184
style (177, 178)
Latli3-rus leaf (507)
Laurel flower (103)
Layering (2), 25
Leaf, anatomical elements of, 173
axil (1), 24
base, relation to petiole, 176
relation to plant stem (477-483),
176
blade, development of (469)
composition of, 26
cvde, 197
.U'velopment of (4, 466-472), 170
dvu'ation of, 175
margin (530-537), 186
origin of (4), 153
I)arts of (3), 26
regions of (468)
sheath, 170
surfaces, 172
classified, 177
texture, 177
Leaflets, 190
Leaves, arrangement of, li)6
as climbing organs, 195
carnivorous, 192
floating, 195
modified, 192
Lecanosperma seed (391)
Legume (350), 123
Lenma stem (456)
Lemon (329), 118
Lens seed (390)
Lepidote, 178
Lespedeza leaf (549)
Leucothoe corolla (95)
Lichen thallus (598)
Lichens (598), 213
Ligulatc (104), 55
Ligule, d(>vcloi)menl of (465 A), 172
Ligulitlorate. 204
Lily bulb (461)
Limb of petal (18)
of perigone (94), 54
Lindera leaf (501 )
stigma (191), 73
Lipped perigones, 56
Liriodendron leaf (507)
Lobed (543, etc.), 188
disk (265)
16
Lobed perigone (97)
Lobelia (96, 153)
inflorescence (583)
Lobing of carpels (216, etc.)
Locelli (138), 31
Locellus (14)
Lochnera flower (124)
Loculicidal dehiscence (315), 115
Loment, 124
Lonicera leaf (5 10)
Lower lip (111), 56
Loxopterygium (178)
Lycopodiaccac, 216
Lycopodiuiu (()04), 216
Lyrate (559), 192
Lysimachia flower (84)
M
Macrosporangium, 30
Macrospores, 29
germination of (278)
Macrosporophyll, 30
Macrosjiorophj^te, 30
Maculate, 178
iMaerna (249)
Magnolia anther (126)
diagram of flower (35)
gynaecium (251)
Main root (439), 158
Male cell, 30, 100
fern, 216
flower (12), 30
gametophyte (278), 100
Malpighiaceae (342)
Malva anther (1-31)
Malvales, 219
Many serialled ovules (227)
Maple fruit (340), 121
Marcescent, 61
Margin of leaf (530-537)
of perigone, 54
Marginal dehiscence (141), 65
Martiincd petioles, 175
Marginicidal dehiscence (317), 115
Mascagnia fruit (342)
Median chorisis, 40
Medical botany, scope of, 19
Meihilla, 141, 146
Medullary rays (421, 423), 141
development of .secondary, 144
Melon, 118
Members, 17
Membranaceous leaf, 177
Menispermum leaf (483)
seecl (397)
Menziesia (137)
IMericarp (335, etc.), 120
Meristem, 136
Meristematic tis.sue, 136
Merten.sia (118, 119)
Mesoearp, 105
Mesophloem, 150
242
IDDEX
Metamorphosis, 46
Microscopes for dissecting, 86
Microscopical botany, IS
Microsporangium, 30
Microspore, development of, 05
germination of (278), 99
structure of, 99
Microspores (14), 30
Microsporophyll, 30
Microsporophyte, 30
Micropyle (241, etc.), 79, 129
jMiddle primary, 184
Midrib (524, a), 184
Millefoliate leaf (556)
Mimulus flower (94)
Minute anatomy, 18
Mitchclla flowers (269, 270)
Mitranthes (88)
Mixed bud, 169
praefloration, 61
Modification of connective (155-164)
Modified leaves (560-569), 192
stems, 165
Modiola ovary (216)
Monadelphous (147), 66
Monandrous (25)
Monks-hood flower (108)
Monocarpellary pistil (219, etc.), 71
Monocarpous, 158
Monochlamydeous and symbol for,
33
Monocotvledonous stem structure (424)
149
Monocotyledons (404), 133, 219
Monoecious flowers (15), 30
Monoeciously polygamous, 31
Monomerous flower (25, 26), 38
Monopetalous, 53
Monopodial stems, 154
Monosepalous, 53
Monospermous fruits (286, etc.)
Monstrosities, 46
Morphology, 19
Moonseed leaf (483)
Moss (595), 214
antheridium, 215
antherozoids, 215
archegonium, 215
capsule (595), 214
development of sporophj'te, 215
gametophj'te (595), 214
sporophyte (595), 214
development of, 215
Mosses, 214
Mucronate, 183
Mullein leaf (477)
Multi-jugate, 192
Multiple fruit, 105
primary root, 159
Musci, 214
Mustard, androecium of (33)
Mycelium, 210
Mycology, 19
Myristica seed (381)
N
Naked bud, 169
flower, 33
ovules, 80
seeds, 129
Napiform (441)
Narcissu.s (116)
Nectar and nectaries (63, 65), 93
Needle-shaped leaf (492)
Nelumbium torus (252)
Nepenthes leaf (560)
seed (392)
Nervature, 184
Nerves (529)
Netted-veined leaves (524, etc.), 185
Neutral flowers (268), 33
in attracting insects, 92
Nicandra (113)
Niederlinia seed (373)
Nocturnal flowers, 93
Nolina seed (393)
Nomenclature, chapter on, 222
Non-essential organs, 32
Notched apex (507)
Nuca (345), 123
Nucellus (241, etc.), 79
Nucleus sheath (424), 150
Nucula (330, 334), 120
Numerical plan indicated by diagram,
(43), 40
formula, 41
symmetry, terminologv of, 37
Nut (345), 123
Nutlet (330, 334), 120
Nutmeg (381)
section of (399)
Nux vomica seed (372)
Nymphaea leaf (473)
Oakesia leaf (480)
Obconical style (183)
Obcordate (506), 182
()l)lanceolate (502), 181
Obhque base (521, 523), 56, 181
corolla (107)
leaf (505)
Oblong (488), 179
elHptical (488), 179
Obolaria (232)
(^bovate (501), 181
Obsolctely (532), 188
Obtuse (511, etc.), 183
Ochrea, development of (472), 172
Odd-pinnate (555), 192
Odor in attracting insects, 92
Oenothera (89)
anther (129)
flower (29)
Ofi-set, 162
Olea flower (31, 32)
OUve flower (31, 32)
INDEX
243
( )nc-fcll(«(l anthers (10'), 166), 6S
( )ii(,"-lipi)0(l roiolla (lOf))
( )ii(>-s('rialletl ovules, 78
Onion bulb (402)
Oogonia, 213
()6si)hore, 213
C)o.s]jore (277)
Oospores in algao, 213
()l)aqup leaf, 177
Open canii)anulate (91)
eollateral bundle, 146
perigone (120)
sheath (465, A, etc.), 170
Opposite leaves, 106
Opuntia fruit (281)
stem (458), 167
Orange, 118
leaf (550, 551)
Orbicular leaf (493), 180
Organic bodies, characters of, 17
kingdom, 17
matter, 17
Organogeny, 19
Organography, 19
Organs, 17
Ortliospornious (335), 121
Ortliostacliy (573), 196
Orthotropous ovule (241), 81
Outer lip (111)
Outgrowth (63), 47
Outgrowths (436), 156
Outline of comjjound leaf, 179
of leaf, 179
Oval (489, 490), 179
elliptical (489), 179
Ovary (9, 10), 32
defence on fruiting (282)
first plan of structure (219, etc.), 76
second plan of structure (225, etc.),
77
Ovate (494), 179
lanceolate (497), 189
Ovoid, 54
Ovule (277, 278)
changes by fertilization, 127
connection between stigma and, 99
internal structure of (277), 98
of gj-mnosperms, 98
parts of (241-244), 79
Ovules (10), 31
direction of (233, etc.), 78
forms of (241, etc.), 80
number of, 78
position of, 78
series of, 78
structure of (241-244), 79
Oxalis leaf (.506)
Paedkria stvle (185)
Palate (94), 58
Palets, 206
Palm fruit, abortion in (285)
Palmate (.548), 190
Falmately compound (547), 190
veined leaf (.527, 528), 186
Palmatifid, 189
Panicle, 203
Paniculate, 203
Panicum (514)
Papaw (309), 118
Papilionaceous (1,10), 57
Papillose, 178
stigma (275)
Pappus, the (74-83), 51
Parenthetical names, 223
Parietales, 219
Parallel veined leaves (526), 185
Parietal i)lacentae (225, etc.), 77
Pari-pinnate (554), 192
Parted (538, 546), 188
perigone (84)
Passiflora (116)
fruit, 125
Paullinia ovule (234)
Pea-fruit (350)
leaf (567)
Peanut (313), 112
Pedate (553), 191
Pedicel (.584, c), 199
Pedicularis leaf (538)
Peduncle (a in 576 and 583), 199
Pelargonium, flower of (48)
Pellucid-punctate leaf, 177
Peltate leaf, 176
stigma (183, 198), 74
Pendant stem, 165
Pendulous ovules (239), 78
Penninerved leaf (524), 186
Peniciliate (208), 74
Pentimerous flower (30), 38
Pentapanax ovary (217)
Pentstemon anther (132)
Pepo (332), 118
Perennial roots, 158
stems, 161
Perfect flowers, 31
Perfoliate leaf (480), 176
Perianth, 33
Periblem (420), 139
structures from, 140
Pericambium (421), 141
Pericarp defined, 105
layers of, 105
Perichaetium, 215
in moisses, 221
Pericycle (421), 141
Periderm, 140
secondary, 140
Perigone, 33
chapter on, 50
color of, 50
form of parts of, 50
number of p'iirts of, .50
special form of, 53
Perigynous (57, 58), 46
Perigyny (57, 58), 46
Peripheral .'nibrvn M()9, 410), 133
244
INDEX
Perisperm, 12S
Peristome of mosses, 215
Perncttya flower (102)
Persistent, 61
leaves, 176
Personate (109), 57
Petal, parts of (18)
Petaloid appendage (loo), 68
Petals, 32
Petiolar glands, 175
Petiole, 26
development of, 172
forms of, 175
for climbing (569)
Petrocoptis seed (385)
Phanerogamic botany, 19
Phanerogams compared with crypto-
gams, 207
Pharmaceutical botany, scope of, 19, 20
Pharmacognosy, 20
Phelloderm, 140
Phellogen (422), 140
Phloem-bundles in root (422), 142
Phlox flower (57), 46
Phores, S3
Phyllanthus branch (460), 167
Phyllocladia (460), 167
Phyllodia (562), 195
Phyllotaxy (570-575), 196
relation to flower-structure, 199
Phylogeny, 18
Physiological botany, 18
Physiology defined, 18
Phytography, 19
Phytomer (1), 23
products of (1), 23
Picea fruit (360)
Pileus, 211
Piliferous layer (416), 139
Pilocarpus leaf (509, 525)
Pilose, 178 1i
Pine leaf (492)
Pinnae, 190
Pinnate (549, etc.), 190
Pinnately compound (549, etc.), 190
veined leaf (524), 186
Pinnatifid (538, 556), 188
Pinnules, 183, 190
Pinus pistil (174), 71
Piper style (181)
Piptoptera fruit (290)
Pistil, gymnospermous, 70
parts of (9, 10), 31
the, 29
Pistillate flower (9), 29
Pitcher plant (560), 192
Pith, 141, 146
Placenta (10), 32
Placentae, modifications of. 77
Plaited, 60
Plantago leaf (481, 515, 527)
Plantain leaf (481, 515, 527)
Platypodium fruit (296)
Plerom (420), 138
structures from, 141
Plumose anther, 68
stigma (209), 74
Plumule (405, 7;^, 133
Podophyllum rhizome (449)
Pollen, fixation of (275). 98
grains (14), 30
development of, 65
tube (278), 99
descent of (278), ICO
Polhnaria (140), 65
Pollination and fertilization, chapter on,
90
by birds, 93
defined, 79, 89
Polhnia (135, 140), 65
Polycarpous, 158
Polycotyledons (406), 133
Polygahneae, 219
Polygamous flowers, 30
Polygonatum rhizome (450)
Polygonum leaf (519)
Polypetalous, 53
Polysepalous, 53
Polystelar stems, 150
Pome (308), 119
Ponthiera pollinia (140)
Poppy fruit (358), 125
Pores, dehiscence by (328, etc.), 66
Position obscured, 42
Posterior side of flower, 41
Potaha style (186)
Potato (446)
Potentilla, flower of (45, 46)
Poterium leaf (488)
Praefloration (120-125), 59
Praefoliation, 169
Preservation of plants, chapter on, 226
Prickly pear (281)
Primary bundles of stem, 146
leaf (466)
root, 145, 158
stem, 162
Primine (241, etc.), 79
Primordial leaf (466)
Prismatic perigone (94), 54
style (183)
Procumbent stem, 165
Produced base (516), 184
Proliferation, 200
Propagation by cuttings, 25
by nodes (2), 25
vegetative, 25
Prosopis fruit (353)
Protection of fruit, 110
to seeds, 110
Proterandry (269, 270), 94
Proterogyny, 94
Protonema, 214
Prunus flower (58)
leaf (490)
Pseudima disk (260)
Pseudocarp, 105
Psorospermum (38)
Psyllocarpus fruit (325)
Pteridophyte, 215
INDEX
245
PubciuU'iit , 177
Pubescent, 177
Pulsatilla flower (10, 286), 32
Pulverulent, 177
Pulviniis, 21), 173
Pumpkin, US
Punctate, 17S
Putanien, 17!*
Pyrene (331), 119
Pvrola leaf (489, 493)
Pyxis (302), 125
QuERCUS leaf (543)
Quinate. 191
R
Raceme (580, 582), 202
Rachis (5S3 and 586)
of inflorescence, 199
of leaf (475)
Radial section of stem (423), 147
Radiate, 204
Radicle (u in Figs. 400, etc.), 133
directions of, 133
Ranales, 219
Ranunculus akene (344)
leaf (540)
petal and nectary of (63)
Raphe (124. etc., 241, etc., 372. 373), SO,
130
Ray-flowers, 204
Rays (587, e), 204
Receptacle (587, h), 204
Reclining stem, 165
Rectinerved, 1S6
Recurved-jiendulous ovule (240), 78
Reduced leaves of inflorescence, 205
Reduplicate (121)
Regular iluplication, 38
suppression, 38
Regul^ritv, law of, 43
Renifonn" anther (131), 63
leaf (495), ISO
Repand (536), 188
Repent stem, 165
Reproduction, sexual, 29
Resupinate ovule (236), 78
Reticulate in special sense (525)
Reticulated leaves (524, etc.), 185
Retwc (512), 182
Reversion of tvpc, 47
Rcvolutc (.VIL o42).^89
Rhamnus (.T^fT
Riiizoids (599), Hit)
Rhizome compared with root, 102
forms of (147-452), 103
Rhizomes (447-452), 1(52
inionil)oi(lal (.')()()), ISl
]{hytid()ma, 140
Ribbon-shaped leaf (4s7)
Ribs (527), 184
Ricinus seed (380)
Ring bork, 140
Ringent (111), 57
Root and stem structure, branching of,
144
cap (410), 139
diapter on, 130
hairs (410),, 139
minute structure of, 138
Roots and stems classified, chapter on,
158
duration of, 158
figures of (437-443)
forms of (441, etc.), 160
from stem, 157
functions of, 160
Root-structure compared with stem-
structure, 145
Rose, flower, double (59)
single (60)
leaf (486, 555)
sepal of (73)
Rosemary leaf t542)
Rosmarinus (542)
Rotate (92), 55
Rotund leaf (493), ISO
Rubus leaf (506)
Rugose, 178
Rules of nomenclature, 222
Rumex (29S)
fruit (283, 289)
leaf (522)
Ruminated albumin (399)
Runcinate (558), 192
Runner (445), 102
Rupturing fruits, 115
Saccate corolla (112)
Sagittate (520), 184
anther (133), 03
Salient teeth, 187
Salix, flowers of (5-13)
leaf (3, 497)
ovary di.ssection (10)
twig (1, 5-13)
Salpichroa (253)
Salverform (101, etc.), 54
Salvia flower (111)
stamen (104) •
Samara (288, etc.), 121
Sanguinaria anther (130)
San t alum disk (200)
Sanvcgesia seed (376)
Sai)onaria inflorescence (584)
Sap-wood, 144
Sarcina (.-)93), 213
Sarraccnia, 171
Sassafras anther (138)
leaf (544)
stamen (70)
Saucer-shaped (103), 55
246
INDEX
Scabrous, 178
Scale-bork, 140
Scalv bud, 169
bulb (461), 168
Scape (576, a), 199
Scariose leaf, 177
Scarious leaf, 177
Scattered leaves, 198
Schizocarp (330, 334), 119
Scion, 25
Sclerotum, 210
Scorpioid raceme (434), 202
Scouring rushes, 215
Scurfy, 177
Scutellaria (151)
Scutellum (415)
Secondary growth in stem, 146
in superficial structure of root,
158
roots, 145
stem, 162
Secondaries (524, h)
Secund branching (434)
leaves, 155
Secundine (241, etc.), 79
Sedge leaf (465, B)
Sedum, flower of (47)
Seed, dissection and examination of, 135
appendages of (384, etc.), 131
chapter on, 127
coats, 129
figures of (369-415)
leaves, 132
method of examination of, 135
parts of, 128
\'itality of, 136
Seeds, provisions for scattering, 113
Seedless plants, 207
Sepals, 32
Septa, 32
abortion of (230), 76, 106
development of new, 106
of fruit, abortion of, 106
Septate, 191
Septicidal dehiscence (316)
Sericeous, 177
Series of plants, 219
Serrate (533), 187
Serrulate (535), 187
Sessile leaf (478)
Sexual reproduction, 29
Sheathing leaf (162)
Shrub defined, 165
Siccose, 116
Sickle-shaped, 182
Sicyos anther (139)
Sidalcea (149)
Sieve bundles in root (422), 142
tissue, 142
tubes (422), 142
Sigmoid calyx (106), 56
Silene, vertical section of flower (72)
Silicic (353-357., 121. 125
Silique (254), 125
Simple fruit, 105
Simple pistil (219, etc.), 71
stems, 164
Sinapis, androecium of (33)
Single and double flowers (59, 60)
Sinistrorse (124), 60
Sinuate (536), 53, 188
disk (263)
perigone (91)
Sinuous anther (139), 64
Sinus, 32
Siphocampylos fruit (328)
Skunk cabbage inflorescence (585)
Sleeping and awakening of flowers, 93
Smilax leaf and tendril (565), 167
Solanum (92), 220
Solidago leaf (478, 496, 502)
Sohd bulb, 168
Sophora fruit (352), 124
Sori, 217
Spadix (585, 586), 202
Spathe (585), 205
Spathyema inflorescence (585)
Spatulate (503), 181
Species of plants, number of, 219
Specific name, 222
Spermatophyta, 219
Spigelia (97)
Spike (583), 202
Spikelet (347, 589), 123, 206
Spines (453), 165
becoming branches (454)
Spinulose teeth, 188
Spiral leaf arrangement (571), 190
Sporangium, 30
Spore germination in cryptogams, 101
mother cells, 65
Sporophyll, 30
Sporophyte, 30
Spur (65), 58
Squash androecium (148)
Staeha fruit (326)
Stamen-circle, the single, 43
column, 46, 66
parts of (12, 14), 31
Staminate flower (12), 30
Staminodia (38, 44), 62
Standard (110), 57
Stele, 141
differentiation of its cells (421)
secondarv growth in, 142
Stellaria flower (39, 40)
Stem and root structure, chapter on, 136
composition of, 26
extensions and appendages of, chap-
ter on, 153
structure compared with root struc-
ture, 145
nionocotyledonous (424)
Stems and roots classified, chapter on,
158
classification of, 161
duration of, 161
order of development, 162
subterranean (444-452), 162
Sterile filament on anther, 62
INDEX
247
Stigma, forms of (191-215), 7.S
papillose (275), 97
position of (191-215), IS
size of, proportional to number of
ovules, 73
Sligmatophyllon (206)
Stipellae (475), 175
Stipulate leaves (474, 475), 174
Stipule, 26
Stipules, development of (471), 171
forms of, 173
Stolon, 162
Stone-fruit, 118
Storage roots (441-443), 160
stems, 168
Stramonium leaf (5231
seed (379)
Strap-shaped (104), 55
Strawberry (304)
calyx (36)
plant (445)
Strigose, 178
Strobile ^360, 361), 126
Strophanthus seed (388)
Strophiole (374), 130
Structural botany, 18
units, modifications of, 26
Strychnos tendril (4551
Style (9), 32
forms of, 72
position of (177, etc.), 72
Subgenera, 219
families, 219
petiolar bud, 157
Subterranean roots, 160
stems, 162
Subulate (499), 181
style (188)
Succirubra bark (426)
Succowia (357)
Succulent leaf (169)
Sucker, 162
Sucking disk (459)
Suffruticose stem, 165
Superior calyx (56), 45
side of flower, 41
Supernumerary bud, 169
Suppression, 38
Supra-axillary bud, 169
Suspended ovules (235, 237), 78
Surfaces of leaf classified, 177
Suture of anther, 65
Sword-shaped leaf (504)
Syconium (362), 125
Symbiosis, 213
Symmeria ovule (233)
Symmetrical Hower defined, 37
Sympodial stems (428-132), 154
Synandrium. 66
Svncarpous fruit, 105
pistil (218, etc.), 70
Syngenesis, 38, 44
Synpetalous, .")3
Synsepalous, 53
Systematic botany, 18
Tabkrn.xemont.vna anther (133)
Tail (115), 58
Taka-diastase, 210
Tamarind, 119
origin of pulp (317)
Tanacetuni, ak^ne of (75)
Tangential section of stem (423), 147
Tapering (514), 183
Tap-root (439), 158
Taraxacum floret (41, 104)
leaf (558)
Taxus pistil (175)
Tegmcn, 129, 131
Tendril of grape, origin of (431)
Tendrils from branches (455), 160
Teratology, 47
Terete, 64
Ternate 191
Tertiaries (524, c)
Testa (376, etc.), 129, 130
Tetrad, 65
Tetrad vnamous (33), 67
Tetramerous flower (29), 38
Tetraplasandra ovary (218)
Thalamiflorae, 219
Thalamus, 33
Thallophyta, 210
Theca (14), 31
Thecaphore (9), 31
Theobroma, petal of (71), 38
Theoretical formulae, 40
Thorns, 165
Thread-shaped leaf (491), 179
Throat of perigone (94), 54
Thvrse, 203
Tig'er lily bulblets (464), 168
Tilia flower (34, 37)
Tissue development, 136
Tobacco seed (378)
Tococa leaf (568)
Tomato, 118
anther (142)
Tomentellate, 178
l'(jinentosc, 178
Toothed perigone (102)
Torsion (49-53), 42
Torus, chapter on, 82
the (16, 23, 24), 33
Transportation of fruit, 107
Transverse section of stem (423), 147
Trape/.oidal, 181
Tree defined, 165
Tribes, 219
Triadelphous, 66
Trichomes, 156
Trifoliolatc (548). 191
Trifolium leaf (548)
Trijugate, 192
1'rimerous flower (28), 3S
Trimorphism, 96
Trinomials, 223
Tri-j)innate (5.56). 192
ternate, 192
248
INDEX
Trumpet-shaped, 54
Truncate, 182
stigma (197), 74
Tube of perigone (94), 54
Tubercles (437), IGO
Tubers (440), 161
T-ufted leaves, 198
Tulip (576)
Tunicated bulb (462), 168
Twining stem, 165
Two-lipped corolla (111)
Two-senallod ovules (219)
Typical flower and modifications, 36
ULMTJsleaf (511, 531)
Umbel (579;, 202
Umbellule, 203
Unicellular plants, 208
Undershrub, 165
Undulate (537), 53, 188
perigone (91)
Unequal leaf (505)
Unequally pinnate (555), 192
Unguiculate, 33
Unguis (18), 33
Unifoliolate leaf (551), 190
Upper lip (111)
Urceolate (102), 54
Urena (330)
Urn-shaped (102), 54
Utricle (341), 121
VAcriNiUM, ovary of (222)
Valerian fruit (293)
Valvate (123), 59
Valves of fruit. 113
Valvular dehiscence (138), 66
Vanilla flower (54)
Varietal name, 224
Varieties, 220
Vegetable sulphur, 216
Veinlets, 184
Veins, 184
Venation. 184
Venus's fly-trap (561), 193
Ventral dehiscence (142), 65
Ventricose corolla (111), 56
Veratrum flower (28)
Verbascum leaf 1,477)
Verbesina fruit (295)
Vernation, 169
Vernonia floret (271)
Versatile anther (129), 63
Vertical extension by branches (431)
Verticil, 196
Verticillate, 196 ^/ ^
141
Vexillum (110), 57
Viburnum inflorescence (268)
leaf (534, 535)
Villaresia ovary (177)
Viola anther (171)
pedata leaf (553)
Violet leaf (519)
Virgin's bower leaf (569)
Viscaria (248)
Vitality of seeds, 136
Vittae (335, a), 120
W
Watermelon, origin of pulp (312)
Water lily, metamorphosis in (62)
Wedge-shaped (518), 184
Wheel-shaped (92), 55
White oak leaf (518)
Whorl, 196
Whorled leaves, 196
Wild-cherry leaf (490)
Willow cone (5), 27
flowers of (5-13)
leaf (3, 497)
ovary dissection (40)
twig (1, .5-13)
Wind-transportation of fruit (287, etc.),
98
Winged petiole, 175
Wings (110), 57
Winter annuals, 158
bud, 161
Witch hazel leaf (505)
Wood-bundles in root (422), 142
fibers, 142
Woody roots, 160
Wyethia, akene of (77)
Xanthium, 122
Xanthoceras disk (264)
Xerophytic, 194
Xylem bundles in root (422), 142
Yeast plant, 210
Yew pistil (175)
Zea style (190)
Zinnia fruit (291)
60
T"^ / N. MANCHESTER.
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