®I|e -§, ^. pm pkarg 1 /6 QK45 KT nir-i S t'Bt'l-SI.SOS sjimssn AiBB3AiNn 3H1S mnmi SiioN 1X191 11191 This book may be kept out TWO WEEI ONLY, and is subject to a fine of FD CENTS a day thereafter. It is due on t day indicated below: Frontispiece, i, cell of fleshy scale of bulb of onion (Allium Cepa) showing cyto- plasm, nucleus and large central vacuole. Chloroplasts: 2, a parenchyma cell of green fruit of carden pepper {Capsicum annuiim) showing cytoplasm, nucleus and chloroplasts; 2a, a chloroplast of a moss (Funaria) showing green granules, assimilation starch grains and protein granules; 2b, a cell near the periphery of the pseudo-bulb of the orchid {Phaius grandifolius) showing cytoplasm and three reserve starch grains formed by leucoplasts, which latter under the influence of light have developed into chloroplasts. Chromoplasts: 3, a parenchyma cell of ripe fruit of Capsicum annuum showmg cyto- plasm, nucleus and yellowish-red chromoplasts; 3a, isolated chromoplasts of carrot {Dauciis Carota). 4. transverse section of petal of wild pansy {Viola tricolor) showmg colored cell-sap in epidermal cells. APPLIED AND ECONOMIC BOTANY FOR STUDENTS IN TECHNICAL AND AGRICULTURAL SCHOOLS, PHARMA- CEUTICAL AND MEDICAL COLLEGES, FOR CHEMISTS, FOOD ANALYSTS AND FOR THOSE ENGAGED IN THE MORPHOLOGICAL AND PHYSIOLOGICAL STUDY OF PLANTS BY HENRY KRAEMER Ph.B. (in Chemistry), Ph.M. (in Pharmacy), Ph.D. (in Botany) HONORARY MEMBER BRITISH PHARMACEUTICAL CONFERENCE; HONORARY MEMBER CONGRES INTERNATIONAL DE PHARMACIE, BRUXELLES, 191 o; CORRE- SPONDING MEMBER SOCIETE DE PHARMACIE DE PARIS; PAST PRESIDENT AMERICAN CONFERENCE OF PHARMACEUTICAL FACULTIES; MEMBER OF THE EXECUTIVE COMMITTEE OF REVISION OF THE PHARMA- COPCEIA OF THE UNITED STATES OF AMERICA, ETC. ILLUSTRATED With 424 plates, comprising about 2000 figures SECOND EDITION NEW YORK JOHN WILEY & SONS, Inc. London: CHAPMAN & HALL, Limited 7/20 Copyright, 19 1 4 BY HENRY KRAEMER Cop3-right, 19 1 6 BY HENRY KRAEMER All Rights Reserved PRESS OF BRAUNWORTH & CO. BOOK MANUFACTUBEBe BROOKLYN, N. Y. LIBRARY N. C. State College PREFACE TO SECOND EDITION. That this work on Applied and Economic Botany has been appre- ciated is shown by the necessity of a new edition in less than two years. It is now fourteen years since the author first undertook to write a book on Botany, and since then he has endeavored to improve each succeeding work to conform to the suggestions and criticisms which were submitted. The reviews of this new work have been uniformly favorable, and apparently the book has given great satisfaction to teachers, students, and those interested in botany. The only criticism that has been offered is that it is perhaps too comprehensive for the average student. This criticism is really the best recommendation of the value of the book and the service it is rendering those engaged in applied science. The training of the analyst and pharmacist can hardly be too complete, as their work touches the very depths of science, and unless their training has been very broad and thorough, they cannot hope to solve the problems that are presented to them. This book, however, was written not only for use as a text-book, but it was intended to be a hand-book or laboratory manual for the graduate after he has entered practical fields. That this has also been realized to some extent is shown by the attestations of many graduates who have found in it just the information which they needed. In the present second edition, the author has carefully revised the text, making such corrections as were necessary and bringing the work up to date. Among the new matter added is a much needed glossary, and a concise statement concerning the nature and properties of the Vitamines, an important group of recently discovered nitrogenous substances. A word might be said in regard to the glossary, which is replete and will be found to supplement the subject matter. It was not until the preparation of this part of the work was fairly under way that it was found that the defini- tions as given in the average glossary and in some of the best dictionaries were frequently inadequate and vague. It is believed that the inclusion of the glossary in this volume enhances its value, and will be appreciated by teachers, students and analysts generally. It may not be amiss to state here that since the appearance of the first edition of this work, the author has published a supplementary volume entitled "Scientific and Applied Pharmacognosy." In this latter work, de- voted to the consideration of drug, food and economic products, the class- ification has been according to their natural relationship. The character- istics of the families comprising them are considered from an anatomical view point, so that the information given supplements that in the Applied and Economic Botany, where the treatment is essentially that based upon their organography or outer morphology. In fact the volume on Pharmacognosy, in addition to its value to pharmacists and analysts, will be of very great interest to botanists as it is in a large measure a treatise on the comparative anatom;^ of plants. September, 1916, H, K. It ., O PREFACE. There are quite a number of books on botany, many of which serve a very excellent purpose. For the most part, however, they are not adapted for the use of students in the applied sciences where the knowledge of botany is to be utilized later in practical work. It is now more than sixty years since Schleiden showed the value of the microscope in the examina- tion of drugs and Schacht demonstrated its usefulness in the study of textile fibers. Since that time quite a number of works have been pub- lished dealing with the microscopy of special technical products, as drugs, foods, fibers, woods, etc., but there have been no text-books which could be employed in the courses on applied and economic botany that would satisfy either the desires of the student or fit the graduate for practical work in commercial life. It is not generally appreciated that there is a depart- ment of applied botany which is distinct from every other phase of botani- cal study ; the point of view and the technique being peculiarly its own and the problems so intricate and important that they should ever be held be- fore the student and command his constant attention. It is almost self- evident that courses in botany which are intended for intellectual culture or scientific discipline are not adapted for technical courses of instruction. In the latter the student has a right to ask for the application of the in- struction which he is receiving and to show an interest in proportion as the instructor is able to demonstrate its value. There are some who consider that a more or less superficial knowledge of botanical principles and micro- scopic technique is sufficient for the student in applied or economic botany. On the contrary, we find that a rather extended knowledge of botany and a very thorough preparation in certain phases of botanical work are absolutely required in order to prepare him to meet and solve the many problems that arise in the commercial world. Many of the commercial problems that are held to be chemical and which are handed to the chem- ist for solution are, as a matter of fact, of a botanical character and can be solved with less expense and less time by the trained botanist. What is really needed is the trained analyst, who, while proficient with chemical methods, is also thoroughly versed in microscopic technique. We have come to a time, if real progress is to be made both in the manufacture of plant materials and in the examination of commercial substances, that it is necessary to bring both chemical and botanical training and knowledge to bear upon the problems involved. Nearly all of the problems upon which one is liable to be consulted in active practice, whether they involve new processes of manufacture or the examination of the finished market material, show at the outset that the analyst must have a very thorough knowledge of the cell constituents and the tissues composing the raw material. It is for this reason that almost one-half of the material of this volume is devoted to the study of V vi PREFACE. cell-contents, forms of cells, and the outer and inner morphology' of higher plants. The facts and illustrations here presented cover not only the latest researches on their morphology, origin, and distribution, but also the most recent advances in regard to their chemical nature. A fair amount of this work is original, and the presentation in one volume, it is hoped, will be appreciated in addition also by students of the plant cell as well as the phyto-chemist. In the practical examination of the crude materials of the market we find more or less contamination with fungi, lichens, and other lower plants, and for this reason, as well as for the understanding of the morphology of the higher plants, a more or less succinct treatment of the Principal Groups of Plants is given in Qiapter I. Another reason which has prompted the author to lay considerable stress on the knowledge contained in this chap- ter is that if the student will master the technique and will apply himself to this part of the work, he will be better prepared to take up the study of the structures of higher plants. The chapter on Classification of Higher Plants is quite extended and illustrated with a large number of photographs, showing not only many of our interesting wild plants but the principal economic plants that are used as foods, drugs, and for other economic purposes, with considerable valuable technical information concerning them. The chapter on Nomen clature has been included in order that the derivations of botanical names might be better understood and their correct spelling facilitated. The chapter on Cultivation of jMedicinal Plants, while especially prepared for those interested in the subject, will be found useful to those interested in other industries where the extermination of native plants is calling attention to practical means for their replenishment. The chapter on Microscopic Technique contains methods for the preparation of commercial materials and much information that doubtless will facilitate practical work. The index contains some 6,000 titles, making the information contained in this volume readily accessible. The work is illustrated throughout, and the legends accompanying the illustrations will be found interesting and instructive and in most instances supplement the information given in the text. All of the illustrations which are not reproductions of photographs and drawings made by the author are duly credited. The author acknowledges the valuable services rendered by his associates in the preparation of the text, reading of proof, and prep- aration of the index; to Professor Wallace Truesdell for assistance in the chapter on Botanical Nomenclature and to Mr. Stewardson Brown for the use of a number of photographs. When larger monographs and authoritative works have been consulted, due credit has been given in the text, so that the present work is a foundation not only of a text-book for students of applied and economic botany but as a reference book for manu- facturers and analysts. November, 1914. H. K. CONTENTS. CHAPTER I.— PRINCIPAL GROUPS OF PLANTS. PAGE Introductory , i Thallophytes 6 Schizophy tes 7 Schizophyceae (Fission Algae) 8 Schizomycetes (Bacteria) 12 Algae 16 Chlorophyceas (Green Algae) 20 Phasophyceae (Brown Algae) 28 Rhodophycese (Red Algae) 31 Diatoms 35 Fungi 40 Phycomycetes (Alga-like Fungi) 42 Ascomycetes (Including Yeasts) 47 Basidiomycetes 56 Fungi Imperfecti 70 Lichens 71 Archegoniates 75 Bryophytes 76 Hepaticae (Liverworts) 80 Musci (Mosses) 84 Pteridophy tes 86 Filicales (Ferns) 87 Equisetales (Horsetails) " 96 Lycopodiales (Club Mosses) 97 Spermophytes (Seed Plants) 100 Gymnosperms ' loi Angiosperms = 1 19 Organic Evolution 128 CHAPTER IL— CELL-CONTENTS AND FORMS OF CELLS. Protoplasmic Cell-Contents i34 Non-Protoplasmic Cell-Contents 140 Factors Influencing Growth, Including Food of Plants 246 Forms of Cells 262 Parenchyma ^^^ Mechanical Tissue 264 Conducting or Mestome Cells 272 Protecting Cells '^^^ vii viii CONTENTS. CHAPTER III.— OUTER AND INNER MORPHOLOGY OF THE HIGHER PLANTS. Introductory = 298 I. Outer Morphology of the Root 299 Inner Structure of the Root 309 II. Outer Morphology of the Stem 320 Inner Structure of the Stem 338 III. Outer Morphology of the Leaf 348 Inner Structure of the Leaf 365 IV. Outer Morphology of the Flower 374 Inner Structure (Histology) of the Flower 402 V. Outer Morphology of the Fruit 408 Inner Structure of the Fruit 42 1 VI. Outer Morphology of the Seed 423 Inner Structure of the Seed 427 CHAPTER IV.— BOTANICAL NOMENCLATURE. . . , 430 CHAPTER v.— CLASSIFICATION OF ANGIOSPERMS YIELDING ECONOMIC PRODUCTS. Introductory 463 Monocotyledons 463 Dicotyledons 501 Archichlamydeae or Choripetalae 504 Metachlamydeae or Sympetalae 643 CHAPTER VI.— CULTIVATION OF MEDICINAL PLANTS Plants Grown from Seeds 728 Propagation by Cutting 733 Collecting and Drying of Drugs 737 Relative Value of Drugs from Cultivated and Wild Plants. . . . 739 Progress in the United States 744 CHAPTER VII.— MICROSCOPIC TECHNIQUE AND REAGENTS. Making of Sections 749 Practical Suggestions 751 Micrometry or Microscopic Measurement 754 Reagents 755 Effects of Important Micro-Chemical Reagents 759 The Micro-Polariscope 764 The Spectroscope in Microscopic Analytical Work 764 Dark Field Illumination and the Ultra-Microscope 765 Micro-Analysis 766 BOTANY CHAPTER I PRINCIPAL GROUPS OF PLANTS INTRODUCTORY There are four main lines of botanical work now recognized, — namely, Morphology, Histology, Physiology, and Ecology. Morphology treats of the form and structure of plants and the subject is sometimes divided into (i) external morphology or organography and (2) internal morphology or anatomy (histol- ogy). The former deals with external characters of plant parts and the latter with their minute inner structure. Physiology may be defined as the study which considers life processes and the condi- tions which influence these. Ecology is the study of the adapta- tion of plants and their parts to external conditions. It is impor- tant to bear in mind, however, that these several departments are more or less interdependent, and that one of them caimot be intelligently studied without a consideration of the problems of the others. Eor instance, as Goebel states, we cannot under- stand the relation of the external forms of organs without refer- ence to their functions. In other words, form and function have a direct relation ; one influences the other. So, too, in the study of ecology we study the influence of external conditions on plants and these, as indicated above, have a direct influence on physiological processes, and thus the study of ecology merges into the study of physiology on the one hand and into morphology on the other. While this book will deal chiefly with the structure of plants and their parts, still it will be necessary occasionally to refer to some of the characters of plants which properly belong to other departments of botanical study. Basis of Plant Structure.— In order to understand the sig- nificance and relation of the various parts of plants it is necessary 2 A TEXT-BOOK OF BOTANY. to know something of their functions and habits of life as well as of their internal structure. It is desirable at this point to give a brief consideration to the cell, as it is the unit of plant structure. If we make a section of a plant and examine it by means of the microscope, the cut surface presents the appearance of a network, indicating that the tissue is made up of small compart- ments or chambers. One of these compartments together with its contents constitutes the structure known as the cell (see Frontispiece). The cell-contents vary greatly in appearance and composi- tion, but in all active or living cells there is always present the substance known as protoplasm. The protoplasm is the basis of all plant structures whether they belong to the lowest or high- est forms ; for by its aid or from it all parts of the plant are developed. Even the cell-wall is a product of protoplasmic activity. The protoplasmic content of the cell consists of several intimately related but more or less distinct portions, — namely, a somewhat thin, semi-liquid, granular portion known as the cytoplasm ; a more or less spherical body embedded in the cytoplasm called the NUCLEUS ; and frequently, but not always, certain small bodies which are more or less variable in shape called plastids, these being also embedded in the cytoplasm (see Frontispiece). The cytoplasm and nucleus are sometimes considered together as a unit, which is known as the protoplast. A fuller discussion of the differentiated portions of the protoplasm will be found in Chapter 11. The lowest organisms, as the slime molds, do not have an enclosing membrane, but consist of a naked mass of protoplasm. With this exception plants have an outer wall or membrane. They may consist of a single cell, as in the Bacteria, or a chain of cells, as in the filamentous Algae, or a mass of cells, as in the majority of plants, and are accordingly designated as unicellular or multicellular. The cell-wall is composed for the most part of cellulose, but may be modified in various ways. Nomenclature. — The names for describing plants have been derived for the most part from studies of the higher plants, they having exclusively attracted the attention of botanists at first. But with the light which has been thrown on the relationship PRINCIPAL GROUPS OF PLANTS. 3 of the higher and lower groups of plants by the more recent study of the lower forms the older terminology has been somewhat modified. Thus, for example, we speak of the root and shoot, with its leaves, as the vegetative organs of the higher plants, and in describing the corresponding organs (where they exist) in the lower plants, we either apply these terms directly, or indi- rectly by saying that the latter are root-like, stem-like, etc. On the other hand, we now speak of the sexual organs of the higher plants as antheridia and oogonia (or archegonia) instead of classifying them roughly as stamens and pistils, the latter names being retained but with a different signification. Plant Organs. — Depending upon the fact that the plant re- quires nourishment for its growth and development and that it has also to carry on the work of reproduction or propagation, — i.e., the production of new plants, — we distinguish between vegetative or nutritive organs and propagative or reproductive organs. The vegetative organs, such as the root, stem and leaves in higher plants, manufacture the food necessary for the life of the plant, while certain other more or less specialized organs or cells carry on the work of reproduction. In the lower plants, however, the whole structure is much simpler, and in some instances a cell which performs the work of a nutritive cell at one stage may become a reproductive cell at another, or, as in the case of the unicellular Algae, all the various functions of the plant may be carried on by a single cell. Generally speaking, there are two principal ways in which plants are multiplied or reproduced: (i) By cell division or cell fission, and (2) by the formation of special cells known as SPORES. In cell division (Fig. 85) the nucleus and cytoplasm of a cell divide to form two new cells or protoplasts, which become distinct by the formation of a wall or cell-plate between the two halves. All growth in plants is dependent upon this method, and in growing parts the cells are said to be in a state of division. Owing to the plasticity of the plant organism, detached portions will often grow and give rise to new plants, as in the case of cut- tings. Growth here as in the parent plant is accompanied by cell division. In some of the lower Algae (Fig. 10) cell division is the only method of propagation, and as only the ordinary vegetative or 4 A TEXT-BOOK OF BOTANY. nutritive cells of the plant are involved in the process it is some- times spoken of as vegetative multiplication. In both lower and higher plants, with the exceptions just noted, reproduction is also earned on by means of spores. Fig. s. Ulothrix zonata. A, young filament with rhizoid cell (r); B, piece of filament showing escape of swarm spores; C, a swarm spore or zoospore with 4 cilia; D, biciliate gametes escaping from a filament; E, F, G, showing difi'erent stages of union of two gametes; H, young zygote or zygospore in which the cilia have been absorbed; J, i -celled plant developed from zygote; K, young plant organizing zoospores. — After Dodel-Port. Depending upon their origin two classes of spores are distin- guished, namely, (a) asexual spores, and (b) sexual spores. In the production of asexual spores the contents of a certain cell called a mother cell or sporangium break up into a number of new cells sometimes called daughter cells, which escape through the cell-wall. In the lower plants, particularly those growing PRINCIPAL GROUPS OF PLANTS. 5 in water or In moist places, these cells are provided with short thread-like appendages known as cilia, which enable them to move about in the water. They are known as zoospores or swarm spores (Fig. 5, B, C), and each individual zoospore is able to produce a new plant. The number of zoospores formed in a sporangium is usually 2 to 8, as in Ulothrix, but the number may be larger. The method of cell formation which gives rise to zoospores is sometimes spoken of as internal division from the fact that they arise within the old cell and retain no relation to the old wall as is the case in cell fission. The zoospores are at first naked protoplasts, but later, on coming to rest, may form a wall. Sexual spores, on the other hand, are formed by the union of two cells known as gametes. When the gametes are similar the resulting spore is known as a zygospore or zygote (Fig. 5, E, F, G). When the gametes are unlike, the spore produced by their union is known as an oospore. In the latter case one of the gametes is larger than the other, is less active, and is spoken of as the female gamete, oosphere, or tgg (Figs. 12, 21). The other more active cell is known as the male gamete, antherozoid or sperm (Fig. 51, ///). The cell giving rise to the oosphere is known as the oogonium (Figs. 12, 21), while the one in which the anthero- zoid or sperm originates is called the antheridium (Figs. 12, 21, 22, 51). PLANT GROUPS. Until a comparatively recent time, botanists divided the plant kingdom into two large groups, as follows: The flowering plants, or Phanerogams, meaning '' reproductive process evident," so applied because the reproduction of the plant was readily seen to develop In the flower through the agency of the pistil and stamens. The non-flowering plants, or Cryptogams, rneaning *' repro- ductive process concealed," so applied to the lower plants like the ferns, mosses, sea-weeds, etc., because in these plants the method of reproduction was not known. Now, however, after a considerable amount of study, It has been learned that a great many of the lower plants have repro- 6 A TEXT-BOOK OF BOTANY. ductive organs which are analogous, even if they are not exactly similar, to those of the flowering plants. Consequently the former classification is no longer applicable, and the following arrange- ment is now generally adopted : Thallophytes j^^^^ [ Fungi Archegoniates [ Bryophytes ( Pteridophytes. Spermophytes | Gymnosperms I Angiosperms In our study of these groups we shall see that in passing from the Thallophytes through the various groups to the Angio- sperms we pass from very simple forms to those which are quite complex. THALLOPHYTES. General Characteristics. — This group comprises those plants which are simplest in form and structure. They are supposed also to represent more or less primitive types. In these the plant body does not show a dififerentiation into root, stem, and leaf, as in the higher plants, and is termed a thallus, the word thallus meaning a " mass " of cells. The cells making up a thallus are all alike and are not differentiated for special functions. How- ever, it must not be thought that every Thallophyte is charac- terized in this way. Many of the Thallophytes have cells or groups of cells which become specialized, i.e., set apart for a particular function, as for example the reproductive cells. We see, therefore, that the word Thallophyte is a general term and is applied to many plants which are not thallus-bearing, but which are really closely related to the simpler forms to which the word Thallophyte is strictly applicable. When made up of a mass of cells they may branch in various ways, but the essential structure remains more or less uniform throughout. The Thallophytes vary in size and general appearance from minute, unicellular organisms to those which are filamentous and delicately branched, and even .becoming leaf-like structures, attaining a length in some of the marine algae of a thousand feet PRINCIPAL GROUPS OF PLANTS. 7 and even more. Some of these are more or less complicated in structure. The Thallophytes are subdivided into two important groups, as follows : The Algae, plants producing chlorophyll or green cell-contents, and hence capable of manufacturing food from the inorganic substances air and water. The Fungi, plants not producing chlorophyll, and hence not capable of forming their own food, but living upon dead or living matter. Before considering the Algae proper we will consider two groups which are very simple in structure and whose method of reproduction as well as life history is also very simple; namely, the Blue-green Algae and the Bacteria. The Blue-green Algae are ordinarily classified with the Algae, and the Bacteria are very often grouped with the Fungi. Owning to certain resemblances between these two groups it is convenient to arrange them to- gether under the name Schizophytes, or fission plants. SCHIZOPHYTES. Characteristics. — The name Schizophyta means " fission plants," and is applied to this group because the reproduction is chiefly by means of the division of the cells, which may occur either at the middle of the cell and in one direction, in which case a series of connected cells are formed, or in two or three directions, giving rise to spherical aggregates or colonies. They do not usually contain chromatophores, and the coloring sub- stance, when present, is either uniformly distributed throughout the cell or occurs on the external surface of the protoplasmic content. There are two chief groups : the one corresponds to Algae, and, while they do not contain a simple green substance, they are for the most part of a blue-green color, although they may assume various shades of orange, yellow, and brown, even appearing chocolate or purplish-red at times. The second group, correspond- ing to the Fungi, comprises the Bacteria or Schizomycetes, which are distinguished for the most part by being nearly colorless and only occasionally of a reddish or green color. 8 A TEXT-BOOK OF BOTANY. SCHIZOPHYCEyE, OR FISSION ALG^.— This group of plants, also known as Cyanophyceae or Blue-green Algae (Fig. 6), are generally found in more or less stagnant water and are charac- terized by having associated with the chlorophyll a definite blue- green principle known as phycocyanin. However, many of these Algae contain other pigments in such quantity as to give them dis- tinct colors much like those found in the red and brown Algae, such as Trichodesmium, a filamentous Alga giving the Red Sea its char- acteristic appearance. Some of these live at the highest tempera- ture known to support life ; some developing, as Gloeocapsa, on the sides of the geysers in the Yellowstone Park. These forms have very wide habits, some living, as Stigonema, in symbiosis with fungi; some, as Nostoc, are endophytic in habit, living in the de- pressions of various plants, and others, as Mastigocoleus, boring into shells. They are found mostly in fresh water, and some, as Uroglena, cause considerable trouble in public water supplies by reason of their breaking down the cell-wall and the liberation of a fetid oily substance. While these plants do not produce true spores, yet they are able to tide themselves over adverse conditions by producing rest- ing bodies through the formation of a thicker membrane and a more concentrated cell-content. In this condition they are able to hold over for several years and then grow when the conditions of temperature, nutrition, etc., are suitable for their germination. As a rule, they grow best in shallow, stagnant water with the rela- tively high temperature of the summer months. When public water supplies are polluted by these blue-green Algae it has been found that the Algae are completely destroyed by the addition of a very small amount of copper sulphate to the reservoir. As small a quantity as one part per million is sufficient to accomplish this result, not only killing the troublesome organisms, but pre- venting their development for some months to come. A few of the common forms will be considered. Gloeocapsa is one of the simplest of the Blue-green Algae (Fig. 6), consisting of spheroidal cells from 0.0035 to 0.005 "^"^• in diameter, of a yellowish or brownish-yellow color, and usually embedded in groups of two or some multiple of four in an olive- PRINCIPAL GROUPS OF PLANTS. T^lG, 6-- Forms of Cyanophyceas or Blue-Green Algae. — Adapted from Engler and Prantl and somewhat modified by Lobeck. lo A TEXT-BOOK OF BOTANY. brown gelatinous stratum, this arrangement due to the cell divid- ing in all directions. They occur on moist earth, stones, wharf pilings, and even on window panes of greenhouses, thus being distributed in both fresh- and salt-water regions. They some- times form a kind of crustaceous stratum, and sometimes soft, slimy masses sufficiently abundant that they can be stripped by the handful from dripping, partially shaded rocks. Owing to the variation in color and general habit of the plant a great many species have been described, but up to the present time about 60 have been sharply distinguished. Oscillatoria, formerly known as Oscillaria, is the name applied to a simple filamentous blue-green alga (Fig, 6) that is char- acterized by movement from side to side as in a pendulum, due, as has been suggested, to the movement of spiral masses of proto- plasm extending from cell to cell. These filaments consist of a series of disk-shaped cells like a pile of coins placed side by side, the end cell being rounded ofif and more or less convex. The con- tents are made up of a finely granular substance differentiated into two areas, a dark central nuclear portion, and a peripheral holding the pigment, which may vary from a bluish-green to dark olive-green or even red sufficiently intense to give the water a red color. The filaments vary from o.ooi to 0.005 mm. in diame- ter, though they may attain a size of 0.050 mm. Oscillatoria is usually found on wet, marshy grounds, in ditches among decayed vegetable matter, on wood subject to hot waste from steam engines, around pumps and cisterns, and in greenhouses. It occurs in fresh and salt water. Lyngbya somewhat resembles Oscillatoria, but does not show any oscillations and the filaments are each provided with a dis- tinct sheath (Fig. 6). It forms late in the summer in large tufts. It is of a bluish-green color, forms long filaments, occurring in the late summer upon Zostera and other Algse. The groups are large and characteristic and have been given the common name Alermaid's Hair. The cells are about 0.030 mm. in diameter. Uroglena is a form which is more or less oval or pear-shaped, about 0.014 to 0.018 mm. in length, and extended into a stalk below, the upper end being provided with two unequal cilia (Fig. 6). The wall secretes a large amount of mucilage. The organisms PRINCIPAL GROUPS OF PLANTS. ii arrange themselves in a radiating sphere, with the ciHa at the periphery. Each cell of the colony contains a more or less spiral, yellowish chromatophore, bearing a reddish spot at one end, a nucleus at the centre, and a few vacuoles. The cells secrete a large quantity of oil, which is of an unpleasant, fish-like odor, and is due either to the decay or breaking up of the cells by mechanical means. This breaking up of the cells is the cause of the disagree- able odor occasionally found in public water supplies. Uroglena is found in New England and has been reported as far west as Indiana, and is probably rather widely distributed in the United States. It seems to thrive best in cold temperatures, usually occurring in greatest numbers when the water is frozen over. It multiplies by cell division, which takes place when the colony becomes rather large. It also produces resting spores which enable the organism to survive conditions which would otherwise exterminate it. A closely related organism, Synura, is responsible for the ripe cucumber odor which was formerly thought to be caused by fresh-water sponges. Nostoc, a form occurring in filaments like a string of pearls, is made up of spherical or elliptical cells, the whole being surrounded by a thick, mucilaginous membrane (Fig. 6). Usually one finds a number of these filaments growing together in a mass which can be seen by the naked eye floating in the water. These masses vary from globular to sub-globular, are irregularly divided or occur in definitely expanded groups. These forms are marked by having two kinds of cells, the one filled with a granular proto- plasmic content, the other being free from protoplasm and some- what larger than the other cells. These latter are fewer in number and are called " heterocysts," which means simply *' other cells." At these latter cells the filaments separate, and thus many new colonies are formed. Nostoc is mostly of an olive-green color, but may be dark bluish-green, dark brown, or light yellow or even colorless. It occurs mostly in fresh-water ponds, seldom in brackish water, being found on damp rocks, on mosses and more or less submerged plants, and variously in limestone springs or wet calcareous rocks or on aluminous soil. The colonies vary greatly in size and color, and while some of them may be of microscopic 12 A TEXT-BOOK OF BOTANY. size at one period, later they may be as large as peas or cherries. Owing to their variation in appearance in different seasons various names have been given to the same form by different investigators. They are also associated with lichens. According to systematists, the forms of Nostoc are arranged according to their aquatic or terrestrial habits. SCHIZOMYCETES, OR BACTERIA.— The Bacteria, or Fission Fungi, occupy rather an anomalous position, some writers classifying them with Fungi and some with Algse. They are i- celled plants, microscopic in size, and of various shape. The con- tents consist of protoplasm and a central body in some cases, which is looked upon as a rudimentary nucleus. They are more or less colorless, but sometimes produce a distinct pigment called bacterio- purpurin which is rose-red or violet, and occasionally a chlorophyll- green color substance. They are capable of multiplying by division in one. two, or three directions, and under favorable conditions in- crease very rapidly in number. The wall is more or less albumin- ous in character, in this respect resembling the wall of the animal cell, and is provided with one or more cilia, or flagella, the number and position of which have been used as a basis of classification. Sometimes the walls of the cells become mucilaginous, so that the bacteria hold together, forming a mass known as a zoogloea. Bacteria may form resting spores which arise in two ways. In one case the contents round off and take on a membrane forming a so-called endospore ; in the other case the plant body is trans- formed directly into a spore known as an arthrospore, as in some of the Blue-green Algse. This body is not strictly a spore, but is in the nature of a resting cell (Fig. 7). Two classes of bacteria are frequently distinguished, as follows : Aerobic, or those which require oxygen for their development and conse- quently grow best when they have access to air or oxygen ; and anaerobic, or those whose development is accelerated under re- verse conditions, as in underlying tissues or in the interior of cultures. Occurrence. — Bacteria occur everywhere in nature, and play a most important part in decay and putrefaction, in that they change dead animal and plant tissues back again into simple inor- ganic substances, as carbon dioxide, hydrogen, water, ammonia,. PRINCIPAL GROUPS OF PLANTS. 13 etc. They serve a useful purpose in many technical operations, as in the making of cheese, acetic acid, fermentation of tobacco, curing of vanilla and many vegetable drugs, and in soil nitrification, helping to change ammonia into nitrates — one of the sources of the nitrogen used by plants. Many of them are disease-producing, or pathogenic, and are the cause of a number of infectious dis- eases in man and the lower animals, and plants as well. They are ^^1 Fig. 7. Bacillus subtilis (hay bacillus), a, Small rod-like organisms such as are found in an infusion of hay, or bouillon; b, zoogloea or mass of bacilli forming the ""skin" on the surface of infusions; c, chains of organisms forming spores; d, individual bacilli showing fiagella, which are only seen after staining. — After Migula. injurious in two ways : in one case they consume the tissues of the host, as in tuberculosis, and in the other they produce powerful poisonous substances, or toxins, as in diphtheria. Classes of Bacteria. — In order to study Bacteria they are grown upon nutrient media, such as sterile bouillon, potato, milk, etc. They are divided into a number of classes, depending for the most part on the shape of the cell: (i) The Sphserobacteria, or Cocci, are those whose cells are spherical or spheroid, and in 14 A TEXT-BOOK OF BOTANY. which division takes place in one, two, or three directions of space. Very few of this group are provided with ciHa. According to the number of cells in a colony they are distinguished as Micrococci, Diplococci, etc. (2) Bacteria proper are elongated, rod-shaped organisms in which division occurs in only one direction, namely, transversely to the long axis, and only after a preliminary elon- gation of the bacterium. The Bacteria are subdivided into two important groups, namely, Bacterium and Bacillus. The Bacilli are motile organisms and produce endospores (Fig. 7), whereas the Bacteria are non-motile and do not usually produce endospores. (3) Spiral bacteria constitute the third principal group and are characterized by the cells being spirally coiled. Division is in only one direction. These bacteria are usually motile, and seldom produce endospores. (4) There is another important group which includes the Sulphur Bacteria, of which the most common one is Beggiatoa. These occur in long threads, and move in an undulating manner much like Oscillaria, one of the Blue-green Algae. They are found in sulphur waters, as in sulphur springs, and contain sulphur granules. Bacteriological Technique. — Principally because of the minuteness in size of micro-organisms a different technique is required in their study from that required in the study of the higher plants. In the first place it is difficult to isolate them so as to be able to study individual forms. Another difficulty is to prevent contamination after they are isolated. And even though a pure culture is obtained it is difficult on purely morpho- logical grounds to differentiate the various forms, as they are all so much alike. I. While it is comparatively easy to prepare a sterile solution, — that is, one in which all life is absent, — it is very difficult to prevent subsequent contamination under ordinary conditions. Even when a cork- or glass-stoppered bottle for keeping liquids is used it is difficult to prevent the entrance into and development of micro- organisms in the liquids. The use of stoppers consisting of plugs of absorbent cotton was first suggested by Schroeder and von Dusch in 1854. They found that if flasks containing liquids, which under ordinary- conditions were likely to decompose, as beef broth, etc., were stoppered with plugs of absorbent cotton PRINCIPAL GROUPS OF PLANTS. 15 and the liquid then boiled for some time it would keep indefinitely. II. It remained for Koch and Pasteur to show what took place in the boiling of the liquid, who at the same time developed the principles of sterilization in bacteriological work. These authors discovered that micro-organisms have two stages of de- velopment, one of which is active and the other resting, the latter being known as the Qgg or spore condition. They found that the organisms in the active condition were completely destroyed on heating the solution containing them for 30 minutes at 100° C. If this solution was allowed to stand for 24 hours or longer there would be evidences of decomposition, which was due to the fact that the spores representing the resting stage of the organ- isms were unafifected by the first heating and developed into the active stage. As a result of further experiments they found that if the solution were heated on the second day for 30 minutes at a temperature of 100° C. the second growth of organ- isms was destroyed, but it was found that the solution might still undergo decomposition in the course of time, owing to the later development of a few remaining spores. It was, however, found that heating the liquid again on the third day was sufficient to kill all of the spores as well as the organisms in the active stage. By repeating these experiments the authors confirmed their observations and established the process known as discontinuous sterilization, which simply means that if a solution of a putrescent or fermentative substance is heated on three consecutive days for 30 minutes at a temperature of 100° C, the flask or bottle being stoppered with absorbent cotton, it will keep indefinitely. Instead of using a plug of absorbent cotton the neck of the flask can be drawn out into a narrow tube and directed downwards (see Re- agents). The time required for producing a sterile solution, — that is, one free from micro-organisms or their spores, — can, however, be much reduced by increasing the temperature, or pressure, or both. By use of the autoclave, in which the pressure can be increased from 10 to 20 pounds, sterilization can be accomplished in 30 minutes by using a temperature of 110° C. III. As already indicated, one of the greatest difficulties is to isolate the organisms. In a cubic centimetre of water there l6 A TEXT-BOOK OF BOTANY. may be a million organisms representing various groups of bac- teria. In trying to solve the problem of their separation it occurred to Koch that if he could secure a medium v^hich was solid at the ordinary temperature and liquid at a slightly higher temperature, he could mix a certain quantity of liquid containing micro-organisms with the medium in a sterile condition, and then by solidifying the mixture the organisms would be fixed, and thus from each organism a colony would be developed which could be isolated and further studied. We are indebted to Koch for the use of solid culture media like nutrient gelatin and nutrient agar in the study of these organisms. IV. The application of stains for differentiating the various organisms was introduced by Weigert in 1877. Staining is of use in the determination of the number of flagella of certain organisms, in the study of spores, and the identification of certain pathogenic organisms, which occur in mucus and pus, as tubercle bacilli, etc. Gram's method of staining is of great use in differentiating many pathogenic as well as non-pathogenic organisms, and is of importance in classifying bacteria. ALG^. Characteristics. — Algae are characterized by their habit of living in water or in moist places. They vary from simple, i -celled microscopic forms to those of great size like the sea-weeds. In the various types, however, the cells show little variation in shape. All the Algae contain more or less of a green coloring matter, even though it may be concealed by other pigments of a blue (as in Schizophyta), brown, or reddish color. The possession of this green cell-content or chlorophyll enables the Algae, in the presence of sunlight, to manufacture food substances from simple materials like carbon dioxide and water. The occurrence of chlorophyll can be readily demonstrated by extracting it with 95 per cent, .alcohol. Even in the most delicate of the red Algae it can be shown by placing the fresh material in a strong solution of common salt and afterwards extracting the chlorophyll with alcohol, the other pigments being unaffected. Algae are sometimes grouped as Fresh-Water Algae, includ- PRINCIPAL GROUPS OF PLANTS. 17 ing most of the Green Algae, and the Marine Algae or Sea-weeds, including most of the brown and red forms. Algae are classified in three natural groups, not only on account of color differences, but because of certain corresponding struct- ural relationships, thus : Chlorophyceae (Green Algae). Phaeophyceae (Brown Algae). Rhodophyceae (Red Algae). Arranging the Algae in this way provides the simplest classi- fication. But in addition to these groups there is another some what isolated group that will be taken up first before the Chloro- phyceae,— namely, the Conjugatae. These are Green AlgcC con- sisting of either single cells or a chain of cells united into threads and further characterized by dividing always in the one direction so that a filament results. They furthermore do not produce zoospores, but produce zygospores as a result of a union of two 'similar or only slightly dififerent cells. After a period of rest they break from the outer membrane and develop directly into new vegetable cells. To this class the Desmids and Spirogyra belong. The Desmids are unicellular Algae, varying from torpedo- shaped to variously branched forms, occurring even in chains. The protoplast is usually separated at or near the middle, where the nucleus is located, dividing the cell into two symmetrical por- tions (Fig. S, E). In the protoplast is a more or less complex chromatophore, through the center of which are distributed a number of globular pyrenoids. The latter are distinct structures embedded in the chromatophores of Green Algae and consist of a central protein substance surrounded by a number of starch grains, and, therefore, give a purple reaction with iodine. Owing to the fact that the Desmids are motile they were formerly con- sidered to be members of the animal kingdom. The movement is slow and steady and largely influenced by the light. There is also a circulatory movement frequently observed in the contents of active living material. In addition, there is almost always observ- able at the ends a well-defined spherical vacuole containing numerous small crystals of calcium sulphate which exhibit a dancing movement due to surface tension and is known as molec- 2 i8 A TEXT-BOOK OF BOTANY. ular or Brownian movement. Reproduction is either by simple division or by the union of two Desmids. In the latter case the contents of each flow together into a connecting tube formed by the union of the two Desmids, the resultant mass rounding ofif to form a zygospore. Fig. 8. Forms of Desmids in longitudinal view and transverse section. A, Mesotaenium Braunii; B, Ancylonema Nordenskioldii; C, Penium Digitus; D, Cylin- drocystis crassa ; E, Closteriu'm moniliferum; F, Spirotaenia muscicola; G, Pleiiro- taenium Trabecula; H, a Docidiiim Baculum; H, a' D, dilatatum. — From Wille in Engler and Prantl's "Die Natiirlichen Pflanzenfamilien." Spirogyra. — Another one of the common Green Algae is Spirogyra (Fig. 9), one of the pond-scums, which in the spring forms floating green masses on ponds and shallow water. The plant-body consists of a chain of cylindrical cells forming long threads or filaments. The transverse walls are sometimes pecu- liarly thickened. The chromatophores occur in one or more spiral PRINCIPAL GROUPS OF PLANTS. 19 bands (Fig. 9, //), which extend from one end of the cell to the other. In these bands are embedded protein bodies known as pyrenoids. The nucleus lies in the centre of the cell and is con- nected with the cytoplasmic layer lining the walls of the cell by delicate threads of cytoplasm. Spirogyra may be propagated vegetatively by one or more cells of a filament breaking ofif and forming new individuals by Fig. 9. II. spirogyra stictica, showing parts of two filaments with band-like chroma- tophores (chloroplasts), in which are embedded spherical pyrenoids. Nuclei are shown in some of the cells with delicate threads of cytoplasm radiating from them. Two of the cells (a, a) of the adjoining filaments (A, B) are beginning conjugation. I, 5. Heeriana, showing different stages of conjugation. In the upper cells, the contents have rounded off previous to the rupture of the adjoining walls of the two filaments. The two middle cells show the contents passing from one cell into the opposite cell. In the lower cell to the right the zygospore is shown. — After De Bary. cell division. The plant is also reproduced by means of zygo- spores, as follows: The cells of two adjoining filaments each send out processes (Fig. 9, //, a, a), which meet; the end walls are absorbed, forming a tube through which the contents from one cell pass over into the other (Fig. 9, /) ; the contents of the two cells then fuse, after which the mass becomes surrounded by a cellulose wall. The spore thus formed may remain dormant over winter, and the following spring germinate and form a new Spiro- 20 A TEXT-BOOK OF BOTANY. gyra filament or plant. This method of reproduction is known as CONJUGATION^ and the zygospore is called a resting spore. It should be explained that certain cells, as well as spores, may lie dormant for a period, as during the winter season or at other times, when the conditions are unfavorable ta grow^th, and then renew their activities, these being known as " resting cells." Chlorophyce.?'. — The Chlorophycese, or Green Algae, are dis- tinguished by usually having a green color, due to chlorophyll, and by having no other pigment. The cells contain one or more nuclei. They are either unicellular or made up of many cells forming fila- ments or flat sheets. They occur either singly as simple cells or in groups representing a single individual or a colony. They are found mostly in fresh or salt water, usually being microscopic in size so as not to be noticed, but often attracting attention when they occur in sufficient quantity to form a scum on the surface. The reproduction is mostly by ciliated cells called zoospores or swarm spores. Reproduction also takes place by the union of the zoospores and through the fertilization of Qgg cells. The sexual spore resulting from this union of like cells (forming a zygospore) or of unlike cells (forming an oospore) seldom develops immediately, but usually undergoes a resting period be- fore growth is continued Protococcus. — One of the commonest of the Green Alga^ as well as one of the simplest is Protococcus (Pleurococcus) vul- garis (Fig. lo). It occurs as a green coating, in both winter and summer, on the moist bark of trees, moist ground, and stone walls, and is a component of some lichens. The plant is i- celled, more or less spherical, and at one stage contains a number of chlorophyll grains which finally unite to form a single plate which lies against the wall and is known as a chromatophore. Besides it contains a considerable amount of oil. An allied species (Protococcus viridis) contains the sugar erythrite. The plant usually reproduces by simple division, — that is, one cell or plant divides to form two. The divisions may continue by the production of another cross wall, so that four cells result. Under favorable conditions, division may take place by the formation of still another wall at right angles to the other two. In this way two, four and finally eight individuals arise which adhere PRINCIPAL GROUPS OF PLANTS. 21 more or less to one another, thus forming colonies. The number of individuals in a colony depends upon the number of indi- viduals in the colony when division begins and the extent to which division is carried. Thus if there were four cells in a colony to begin with and division took place in three planes, there would be thirty-two cells in the colony at the end of the period. The development of the green coating on the barks of trees, due to the growth of Protococcus and the protonema of mosses, is usually thought to be more pronounced on the north side. This, however, is a slightly false notion. The fact which determines the position of these plants is the quantity of moisture available. The south and southwest sides of trees in the northern hemisphere are exposed to more light and heat and consequently are apt to be drier, with the result that they are rarely covered with coatings of Fig. 10. Protococcus vulgaris. DiflFerent stages of division of the cell. — After Wille. Protococcus and mosses. The under side of slanting trees is a very favorable place, as are also the lower slanting surfaces near the ground of large upright trees, because in these places the water is more likely to be conserved. A careful investigation by Kraemer showed a more abundant growth of green plants on the east and southeast exposure, although the north side of many trees showed good growth also. Volvox occurs widely distributed throughout the United States in ponds and pools of fresh water. It is most abundant in warm weather, but also found in midwinter. It appears as a minute spherical colony about y2 mm. in diameter, made up of numerous cells, the number ranging from several hundred to many thousand (Fig. 11). The cells at the periphery are pro- vided with cilia, so that the colony rolls slowly through the water. Each cell contains a chloroplastid in which starch granules and often a- red pigment spot are present. The asexual reproduc- 22 A TEXT-BOOK OF BOTANY. tion is through the formation of daughter colonies within the mother colony, and these after a time develop motile cells like the parent, which swim about and finally escape. A sexual method of reproduction also occurs in which there is a union of cells within the spheres, the resulting cells after germination forming swarm spores that cling together to form a new colony. Hydrodictyon, or Water Net, is a form often very abundant in sluggish and stagnant waters. It consists of a number of cells forming a net, the meshes of which are usually hexagonal or pentagonal in shape, depending on the number of cells outlining them (Fig. ii). The cells are all alike, cylindrical in form, attaining sometimes a length of i cm., and usually contain a number of nuclei. The green chromatophore occurs in a plate at the periphery of the cell and usually contains numerous pyrenoids. The asexual reproduction is by means of zoospores which are formed simultaneously in large numbers, sometimes number- ing many thousands in each cell. These zoospores as formed inside of the mother cell show more or less definite movement and arrange themselves finally to form a new net. The sexual reproduction is characterized by several stages, (i) Some of the zoospores are liberated through a pore in the cell- wall of the mother cell and after swimming around for some time pairs of them unite, forming zygospores. (2) After a resting period each zygospore develops 2 to 5 zoospores, which escape into the water and develop into irregular, sharp-angled cells, called polyhedra, which persist through the winter. (3) When these polyhedra develop, small zoospores are again formed, and these arrange themselves to form a net inside of the polyhedron, which then escapes and increases in size. Vaucheria (Fig. 12) is another common green alga which may also be selected as showing the habits of this group of plants. The plant has a branching thallus and lives in shallow water or on moist earth, being attached to the substratum by means of delicate root-like processes sometimes spoken of as rhizoids (Fig. 12, w). In the thin layer of protoplasm lying near the wall are numerous nuclei and small oval chromatophores. PRINCIPAL GROUPS OF PLANTS. 23 Fig. Forms of Chlorophyceae or Green Algae. — All adapted from Engler and Prantl except Ulva. Drawn by A, K. Lobeck. N. C. SttU CWkfi 24 A TEXT-BOOK OF BOTANY. Numerous oil globules are also found in the protoplasm, and cal- cium oxalate cr}'stals may occur in the cell-sap. Vaucheria furnishes an example of a plant whose interior is not segmented by cell-walls. In other words, the cavity within the outer or enclosing membrane is continuous, and such a plant is said to be coenocytic, — i.e., like a syphon. But it should be borne in mind that the plant contains a great many nuclei, and. as we have seen (page 2), a nucleus with its associated cytoplasm Fig. 12. Vaucheria sessilis. A, sporangium from which the multiciliate zoospore is escaping; B, resting zoospore; C, D, germinating zoospores with growing point (s); E, plant showing root-Hke organ of attachment (w), spore from which the plant is developing (sp); F, showing in addition two oogonia (og) and an antheridium (h). — After Sachs. constitutes a unit of work. Hence such a plant as Vaucheria is in a certain sense equivalent to a plant having as many uninucleate cells as it has nuclei. It would probably be better to call such a plant multinucleate rather than unicellular. Reproduction by means of asexual spores is brought about as follows (Fig. 12, A) : A cross wall is formed near the end of one of the branches, the end portion constituting a sporangium. The contents, including numerous nuclei, group themselves into one large zoospore, which escapes through an opening in the sporan- PRINCIPAL GROUPS OF PLANTS. 25 gial wall, and after swimming about for a time comes to rest and germinates, giving rise to a new plant (Fig. 12, C, D). This large zoospore is multinucleate and multiciliate, there being two cilia for each nucleus, and by some botanists is considered to be an aggregation of numerous biciliate zoospores. It is also of interest to note that the zoospores of Vaucheria appear to arise by a grouping of the cytoplasm and the nuclei already existing in the sporangium rather than by repeated divisions of a single nucleus. Another method of reproduction in Vaucheria (Fig. 12, F) is that by means of oospores, or spores formed by the union of egg and sperm cells. Two special branches are formed on the thallus as short side shoots. One of these branches, known as the oogonium (Fig. 12, og), is somewhat egg-shaped and sepa- rated from the thallus by means of a cross wall. It contains a great many chromatophores and considerable oil, and has a com- paratively thick wall. The apex is somewhat beaked and con- tains colorless protoplasm. The second branch, which is known as an antheridium (Fig. 12, h), is smaller, somewhat cylindrical and curved towards the oogonium. It is also cut off from the thallus by means of a cross wall. The antheridium contains very little chlorophyll, but a great many sperm cells. These are oval or egg-shaped and have two cilia, one at each end. The sperms escape from the apex of the antheridium and enter an opening at the apex of the oogonium, one of them uniting with the egg cell, which then develops a thick membrane, the resulting oospore being a resting spore. Ulva, or Sea Lettuce, is a common form found all over the world, especially in brackish waters. In its usual form it consists of fiat, thin, unbranched fronds which are more or less ovate or orbicular in outline and frequently deeply incised, sometimes be- coming linear or even ribbon-shaped (Fig. 11). The fronds con- sist of two layers of cells, which are either in close contact with each other or else at maturity separate so as to form a tubular frond. It sometimes occurs in large quantities in the shallow water along our coast, and is conspicuously disagreeable by its resemblance in shape to the swollen intestines of some animal. CEdogonium is a filamentous alga occurring usually in simple unbranched filaments and attached by a disk-like cell or hold- 26 A TEXT-BOOK OF BOTANY. fast (Fig. ii). It occurs in meadow pools or ponds, frequently in streams attached to rocks near rapids. The cells are somewhat elongated and contain a large, irregular chromatophore with pyrenoids. Most of the cells are vegetative cells, interspersed among which are the cells producing the spores. Zoospores are produced singly in the cells and are provided with cilia at one end. After swimming about for some time they attach themselves at this ciliated end to a substratum and develop into filaments. Two other types of cells are formed, which give rise either to oogonia, the female organ containing a large egg cell, or to antheridia, the male organ containing many sperms. The union of a sperm with an egg cell produces an oospore with a very thick wall, capable of over-wintering and developing again when con- ditions are favorable. The Charace/E, or Stoneworts, is a highly differentiated group that is considered as a distinct class between the Chloro- phycese and the Phseophyceae. They stand so entirely by them- selves that many authorities do not consider them as even Algae. They consist of jointed stems, from the nodes of which whorls of from 4 to lo so-called leaves arise, the sexual organs being axil- lary (Fig. 13). In many of the members of this family the cell wall is incrusted with lime salts. Chara occurs in great masses in the bottom of ponds and shallow lakes. It occurs in sufficient quantity in many places so that the body of water has a distinct orange color, due to the immense numbers of antheridia. The plant is of such luxuriant growth that if single individuals are kept in an aquarium or large glass vessel it will greatly multiply during the winter and persist for many years. In ponds where Chara occurs large quantities of lime are deposited, so that in ancient deposits now exposed to view one often finds imbedded therein the remains of the spore-fruits. In the long cells or internodes there is a large vacuole and a thin layer of protoplasm containing a central nucleus and a large number of oval or lens-shaped chromatophores. In some forms, especially in Nitella, the inner protoplasmic layer shows a streaming movement. This is very interesting, as a distinct streaming movement does not occur in most plants and is limited to a few water plants, the staminal hairs of Tradescantia, the leaf PRINCIPAL GROUPS OF PLANTS. 27 hairs of Cucurbita and Llrtica and the hyphae of Rhizopus, etc. This streaming movement in plants Hke Characese, as pointed out by Pfeffer (Physiology of Plants), has in most cases a definite purpose. It is, in any case, always possible that the streaming movement may be an accessory but unavoidable accompaniment of some other form of vital activity. In Chara and Nitella the Fig. 13. Stonewort or Chara. At left showing the habit of the plant with minute reproductive organs on the leaves. At right enlarged view of reproductive organs. A, mature organs showing (a) antheridium, (S) oogonium surmounted at the top by a crown of cells (c); b, stem of plant; fi' , /3", whorl of leaves, some of which have been removed, as at /3; B, a young antheridium (a), with young oogonium (SK), together with the adjoining cells of the stem; the whorl of leaves not represented. — A, after Wille; B, after Sachs. Streaming endoplasm (inner layer of protoplasm) does not cover more than 2 to 3 mm. per minute. The activity of the streaming is influenced by sunlight, oxygen, acids, chloroform, etc. Two kinds of protoplasmic streaming are recognized: ( i ) in which the movement is confined to the layer enclosing the central vacuole, that is known as " rotation," and (2) in which the streaming follows more or less irregular paths up and down the strands of protoplasm, crossing the latter, which is called " circulation." 28 A TEXT-BOOK OF BOTANY. Vegetative reproduction is much like that of the higher plants, through the production of root-tubers or bulbils, stem bulbils, and through special branches arising at the nodes. The bulbils are filled with starch and are capable of over-wintering. The sexual mode of reproduction is through the activity of oogonia producing oospores, and antheridia producing antherozoids or sperms. These are adjacent to each other at the nodes, the oogonium forming a central elliptical cell which is surrounded by a crown of cells through which fertilization takes place (Fig. 13). PhvEOPhyce.e. — The Phseophyceae, or Brown Algae, are dis- tinguished by having brown chromatophores. They are mostly found in the colder waters of the ocean, and are either free or attached to a substratum. They .vary in size from microscopic organisms to delicate filamentous or cord-like forms, and may be- come of enormous size. Some are called rock-w^eeds and give the characteristic color to the rocks between low- and high-tide marks. Others are known as *' kelps," and these grow near the low-water mark. They vary in color from an olive-green to a brown. The chlorophyll may be extracted by alcohol, leaving the other pig- ments, phycoxanthin and phycophcein. Many of these Algae are rich in iodine, being one of the sources of this element. They also contain large quantities of sodium, and were used at one time in the manufacture of sodium, and have been used to fertilize the soil in parts of Europe as well as in New England. They are more complex in form than the Green Algae, and are distinguished by having hold-fasts which, while not in the nature of true roots, yet serve to hold the plant. They may also develop stems and bear leaf-like structures of many varied forms. Others also develop swollen bladders which contain oxygen and which serve to buoy up the plant. Fucus, or Bladder Wrack, is one of the common rock-weeds (Fig. 14, B). It grows near the surface of the water, attached to rocks, and produces a regularly dichotomously branching thallus. Some of the forms in the upper branches produce air bladders which are spherical or slightly elongated and usually in pairs. The margins of the branches are either entire or somewhat serrate. The tips of older branches become more or less swollen and are termed receptacles. They are dotted over with minute PRINCIPAL GROUPS OF PLANTS. 29 cavities, called conceptacles, and these contain the reproductive organs. These consist of oogonia and antheridia, which may be Fig. 14. Some common marine algae. A, Laminaria, showing portions of three leaf- like thalli and hold-fast; B, dichotomously branching thallus of Fucus; C, Sargassum, or "gulf weed," showing a thallus resembling a leafy branch, with swollen, berry-like air bladders, which act as floats; D, Dasya, a delicate branching filamentous sea- weed, attached to a blade of eel-grass; E, dichotomously branching thallus of Chondrus, or Irish moss; F, leaf-like thallus of Grinnellia; G, densely, but delicately branched thallus of Polysiphonia. A, B. C are Brown Algae and D, E, F, G are Red Algae. present on the same or on different plants. The egg cells and the sperm cells escape into the sea-water, and after their union an 30 A TEXT-BOOK OF BOTANY. oospore results, which, upon finding a favorable resting place, begins shortly to develop into new Fucus plants. The plant contains both iodine and bromine, chiefly combined with salts of sodium and potassium, and was at one time used in medicine. It also contains a bitter principle and a considerable amount of mucilage. AscoPHYLLUM, a rock-wccd closely related to Fucus, is dis- tinguished from this genus by the fact that the branches are desti- tute of midribs and the spores occur in groups of four instead of eight. The frond is thick and narrow, branching somewhat dichotomously, and at intervals produces large, conspicuous floats, which are broader than the frond. The plants occur from j/3 to 2 metres in length. The fruit is found in lateral branches in winter and spring, and in June the receptacles fall off and are sometimes found in immense quantities, covering the bottom of tide pools. Laminaria is one of the common kelps or devil's aprons which inhabit principally the colder seas of high latitudes. They all grow in pools at low-water mark, attached to the rocks and in deep water, and some attain a very large size. The species vary greatly in outline and habit according to the season and place of growth — whether on an exposed or sheltered coast or partly ex- posed at low tide. It consists of three parts (Fig. 14, A) : a long, leaf-like expansion or blade supported by a more or less cylindrical stalk or stipe, which in turn is attached to the rocks by a hold-fast made up of a cluster of fibrous outgrowths. In general the species may be classed in two groups, one in which the frond is ribbon-like or long in proportion to the breadth and not split up into segments, and the other in which the frond is proportionally broader and fan-shaped and laciniate. To this latter belongs the Laminaria digitata. There are some 25 species, distinguished by the arrangement of root-fibres comprising the hold-fast, the structure of the stipe, whether solid or hollow and whether provided with distinct cavities containing mucilage, the shape, especially of the basal portion of the lamina, and the char- acter of the margin and the position of the fruit. The growing portion of the lamina is at the base, as in the leaves of the Spermo- phytes. The kelps of the Pacific Ocean are among the largest sea-w^eeds known, the Giant Kelp, Macrocystis, attaining a length PRINCIPAL GROUPS OF PLANTS. 31 of nearly a thousand feet. Other forms have large floats at the base of the lamina. Reproduction is chiefly by zoospores formed in I -celled sporangia which occur either in dispersed patches or in continuous bands near the centre of the frond. Sargassum, or Gulf Weed, grows attached to rocks by means of disk-like hold-fasts (Fig. 14, C). When it is torn from the rocks it is carried into the open ocean by currents such as the Gulf Stream. Sargassum is most highly organized and is represented by a very large number of species. They are found especially in the warmer waters near Australia, Japan and the adjacent coast of Asia, and also in the West Indies and at various parts of the Atlantic Coast near the Gulf Stream, some occurring as far north as Cape Cod. The plants vary from 15 cm. to nearly 2 metres in length, and consist of a stem-like axis which bears leaf-like branches with a distinct midrib, berry-like air sacs on stalk's, and reproductive branches or receptacles. Rhodophyce.^. — This includes all the Algae which are of a reddish or violet color. They contain chromatophores in which the chlorophyll is masked by other pigments, mostly red, and known as phycoerythrin or rhodophyll. The red Algse are mostly found in salt water, occasionally in fresh and running water. They are usually found growing upon other plants or variously attached to some substratum. They vary from microscopic forms or very delicate filamentous types to large plants. They are usually composed of a number of cells or filaments which are so closely arranged as to resemble the tissues of higher plants. Many of the cells are connected by strands of protoplasm, giving them a rather characteristic appearance. Others have an in- crustation of lime on the wall. They are mostly found in deep waters of the Tropics. Reproduction is almost entirely by sexual or asexual spores. Chondrus, or Carragheen or Irish Moss (Figs. 15, 16), is a common rock-weed found at low-water mark, and in this country is common from New York northward, being extensively col- lected at a few points about 15 to 20 miles south of Boston. The plant varies considerably in color, being more or less green when close to the surface of the water and of a deep purplish-red when growing at some depth. It varies from 4 to 15 cm. in length, and 32 A TEXT-BOOK OF BOTANY. is attached to rocks by means of a slender hold-fast. The thallus is dichotomously branching, somewhat flattened, but may be quite linear. The fronds show a mucilaginous modification of the cell- walls. In the upper segments occur small differentiated areas. itm^MsL ^ ^ i 1 ] ^ Fig. 15. Specimen of Chondrus crispus still attached to the rock where it was found growing along the Massachusetts coast. sometimes called sori, of a more or less elliptical outline, which on sectioning are found to be in the nature of sporangia, contain- ing numerous tetraspores (Fig. 16). The spores are discharged through narrow canals extending through the more or less com- pact outer layer of the frond. The article found in commerce has the color removed by being bleached through the action of the sun PRINCIPAL GROUPS OF PLANTS. 33 and dews. It shows, however, all the morphological structure of the growing plant. Fig. i6. Chondrus crispus: A, B, C, D, various forms of thallus; H, hold-fast; F, sporangia; T, transverse section of thallus showing epidermis (E), sporangium with spores (F); S, spores separated in glycerin preparation of thallus by pressure on the cover-glass. The spores occur in groups of four (tetraspores) and the tetrad group is about 30M in diameter. In a closely related genus, Gigartina (Fig. 17), which is found in imported Chondrus, the fruit bodies occur in numerous cylindri- 3 34 A TEXT-BOOK OF BOTANY. cal outgrowths developed on the surface of the fronds. This form is found more abundantly north of Boston than south, but, as Chondrus is collected at Cohasset, Scituate, and other towns south of Boston, it is not seen in commerce in this country. Rhodymenia, or Irish Dulce, is one of the commonest red sea-weeds in the North Atlantic Ocean, usually growing with Fucus, Laminaria, and other Algae between tide marks and extending into deep water. The fronds are purplish-red, flat, membra- Fig. 17. Gigartina mamillosa. a red sea-weed closely related to Chondrus crispus. showing a dichotomously branching thallus and bearing at the upper part numerous cylin- drical outgrowths in which the fruit bodies (sporangia) are found. — After Kutzing. naceous, 15 to 30 cm. in length, irregularly cleft, palmate or dichotomous, the margin often being marked with numerous small divisions. The sporangia occur in scattered patches im- mersed in the cortical tissues of the frond. It is a common article of commerce and is said to possess anthelmintic properties. Agar-agar is derived from several of the marine x\lg3e grow- ing along the eastern coast of Asia, notably species of Gracilaria, Gelidium, and Gloiopeltis. It is a mucilaginous substance which is extracted from the sea-weeds, and is used extensively as a PRINCIPAL GROUPS OF PLANTS. 35 culture medium in bacteriology and in other work where a nutrient is desired. It occurs commercially in bundles 4 to 6 decimetres in length, consisting of thin, translucent, membraneous, agglutinated pieces, yellowish-white in color. It is usually brittle, but becomes It is used in medicine in the powdered tough when moistened Fig. 18. Arachnoidiscus Ehrenbergii, a characteristic Diatom found in Agar-agar. — From a photomicrographic negative by J. J. Woodward, Surgeon, U. S. A. form. Under the microscope Agar-agar frequently shows the frustules or siliceous cell walls of diatoms, which are disk-shaped (Fig. 18). It is insoluble in cold water, but dissolves slowly in hot water. LTpon boiling i part in 100 parts of water it should yield a stifif jelly upon cooling. Diatoms constitute a large group of unicellular plants, occur- 36 A TEXT-BOOK OF BOTANY. ring in both fresh and salt waters. They form the plankton or floating microscopic life found in oceans and lakes, which is the source of food of small animal forms inhabiting these waters. The mud at the mouths of many rivers, the sediment of ponds, ditches, and even rain troughs may contain great numbers of these minute organisms. They have been found in the polar ice, and have been detected in the dust evolved from volcanoes. One of the distinguishing characters of the group is that the cell wall is incrusted with silica. For this reason they are practically indestructible and form marls and strata in the earth. They occur either singly or grouped in bands or chains. They are very variable in shape, being boat-shaped, ellipsoidal, spherical, or peculiarly curved in some forms. They are either free or attached to a substratum, as stones, water plants, etc., those which are free having an active movement (Fig. 19). The cell wall of Diatoms practically consists of two halves, one fitting over the other like the lid of a box. These are known as " valves " or " theca." The manner in which the two valves are joined results in the formation of a " girdle " or " pleura." The girdle is provided with a series of pores conecting with canals at either end and in the middle, through which food from without is supplied to the protoplast. The valves are very often beautifully marked by a series of parallel cross lines, dots, cir- cles, or polygons, which are characteristic of the different groups. Some forms are used in testing the definition of objectives, as Pleurosigma augulatum, in which the lines are one-half micron (0.0005 mm.) wide (Fig. ig, A). In the Diatoms the protoplasm lies as a thin layer close to the wall surrounding a large central vacuole. The nucleus is sur- rounded by a relatively dense mass of cytoplasm, and occurs in definite positions according to the species. The chromatophores frequently occur in plates which are typical for certain species. They are sometimes greenish-yellow, the color being generally masked by the presence of a brown substance known as diatomin. They frequently contain pyrenoids, which are sometimes asso- ciated with granules of starch. Reproduction takes place by simple division or fission, the two valves separating and a new valve forming on each half to replace PRINCIPAL GROUPS OF PLANTS. 37 the old one. In each case the valve formed fits into the old one, and hence in the case of the smaller valve the new cell or plant becomes smaller than the parent plant, the walls not being able to expand on account of the siliceous composition. In this way^ the cells of one series gradually becomes smaller and smaller until a certain minimum is reached, when the plant rejuvenates itself F;g. 19. Diatoms: A. Pleurosigma atienuatum as seen from above; B, Pleurosigma halticum as seen from the girdle side; C, D, E, Fragilaria virescens showing colonies attached to an alga in C, a view of a single diatom from above at D, and a chain of diatoms viewed from the girdle side at E; F, G, two views of Navicula viridis; H. I, the formation of auxo- spores in Navicula firma, H showing the exit of the protoplasts and the throwing ofT of the original valves.— A, B. D, after Van Heurck; C. E. after W. Smith; F-I, after Pfitzer. by the production of spores (auxospores). These are formed in two ways : In one case the valves separate from each other, the protoplast escapes, grows larger and develops a new wall ; in the other case, of which there are several types, two individuals come together, and envelop themselves in a mucilaginous covering. They then throw off their siliceous walls and the protoplasts unite to form a zygospore, which grows until it is thiee times the 38 A TEXT-BOOK OF BOTANY. original size, after which it develops a new wall, the larger valve forming first (Fig. 19, H, I). DiATOMACEous Earth, also known commercially as " In- fusorial Earth," or '' Kieselguhr " (meaning siliceous marl), occurs in extensive deposits, some of these, as the stratum at Richmond, Va., extending to a depth of 18 feet. These deposits consist of the siliceous walls of the Diatoms, which, owing to their composition, are practically indestructible, and are accumulated in those localities which have favored the growth of the organ- ism. The natural deposit is mined and usually calcined to de- stroy the organic matter, after which it is washed and dried. The article used in pharmacy is further purified by boiling with diluted hydrochloric acid, washing, and calcining. This purified product is known as Terra Silicea Furificata, and occurs in the form of an almost whitish, or light grayish, or light brown powder. It is odorless, insoluble in water and in mineral acids or dilute solutions of the alkalies. Under the microscope mounts made in water or solutions of hydrated chloral show the frustules or siliceous walls of the Diatoms. In the better grades of Diatoma- ceous Earth the entire skeleton with the characteristic markings is present. Material coming from various localities shows a differ- ence in genera of Diatoms. The exact naming of the species requires the assistance of specialists. In order to avoid confusion it is necessary to bear in mind that there are two and sometimes even three views which may be obtained of the same Diatom. Diatomaceous Earth consists of about 85 per cent, of SiOo, 10 per cent, of water, and 5 per cent, of clay, iron oxide, magnesia, lime, and organic material. Owing to the fact that Diatomaceous Earth is made up of the hollow shells of Diatoms, it has the property of absorbing by capillarity gases and liquids. For this reason it is used in the preparation of dynamite ; the highly ex- plosive nitroglycerin being absorbed by the diatomaceous shells, rendering the product capable of being handled. When calcined, it will absorb its own weight of water. It is used in pharmacy for filtering and as a diluent for powdered extracts, etc. Among the technical uses may be mentioned : polishing of metals and woods, insulating steam pipes and electrical insulators, packing of caustic and inflammable liquids, and the manufacture of glass, paper, and PRINCIPAL GROUPS OF PLANTS. 39 soap. It is also used to some extent in dermatology. In India it has been used as a rubefacient. In Sweden, and among the Chinese and Laplanders, Diatomaceous Earth has been used as an Fig. 20. The Algae are put to various uses by the people who collect them. The illustration is taken from an ornament purchased at the Louisiana Purchase Exposition and was made by the FiUpinos from various kelps having large, bladder-like floats. edible earth under the name of " mountain meal " or " bread- stone." Humboldt also calls attention to the fact (Aspects of Nature) that the practice of eating earth is diffused throughout the torrid zone, among indolent races inhabiting the finest and 40 A TEXT-BOOK OF BOTANY. most fertile parts of the globe. It is a saying even among the most distant of the different tribes living on the Orinoco, when speaking of anything very unclean, that it is " so dirty that the Otomacs eat it." Economic Uses of Alg^. — Many of the Algae are of use as food, of which the following may be mentioned : Vaucheria fasti- giata, Griffithsia coralina, Ceramiuui Loiireirii, CJiondrus crispus, Gigartina mafnillosa, Gelidiiim cartilagineum, Gelidium crinale (yielding agar-agar), Rhodymenia palmata (yielding dulse), and several species of Gracilaria (which also yield agar-agar). Some of the sea-weeds are used in the production of iodine, as Durvillcca utilis, Ascopliylliim nodosum, Fuciis vesiculosus (bladder-wrack), Sargassum linifoliiim, Laminaria saccharina, Laminaria digitata, Alaria esculenta, Rhodymenia palmata, Phyl- lophora memh rani folia, Macrocystis pyrifera, and Fastigiaria furcellata. A number of the Algae are also used in medicine, particularly for phthisis, as Fuciis cartilagineus, Stilophora rhizodes and Dictyopteris polypodioides. Alaria esculenta and Laminaria digi- tata are used in the making of bougies and tents used in surgery. Owing to the toughness of some of the Algae on drying, the material is used in the manufacture of various articles, as handles for tools from the thick stem of Lessonia fucescens, fishing lines from Chordaria Hagelliformis (Fig. 20), etc. FUJs^GI. The Fungi form a large group of plants which do not produce chloroplasts or any bodies having a similar function. They have not the power of carbon dioxide assimilation, — that is, unlike the Algae, they are unable to manufacture food materials, such as carbohydrates (starches, sugars, etc.), from carbon dioxide and water. Hence they are dependent upon previously formed food products, and may derive their food from living plants or ani- mals, when they are known as parasites, or from decaying animal or vegetable matter, when they are known as saprophytes. The living plant or animal atacked by a fungus is known as the host. Fungi are especially characterized by the habit of arising from spores and of producing thread-like cells the growing poiat PRINCIPAL GROUPS OF PLANTS. 41 of which is at the apex. These threads are known as hyph.^ (singular hypha). They branch and become interwoven, forming a mass or mat known as the mycelium (Fig. 23). The myce- lium constitutes the plant body proper, and absorbs the food material from the substratum, which it ramifies, often causing decay. The mycelium is frequently not visible, and the presence of the fungus is not recognized until the so-called fruit bodies are developed, as sometimes seen in the case of moldy oranges, mildewed linen, and as illustrated by the common mushroom. The mycelium has a cellulose wall which in some cases is modi- fied to chitin, a nitrogenous substance related to animal cellulose and found in crabs and other lower animals. The protoplasm either occurs in a more or less delicate form lining the hyphae and enclosing large vacuoles, or is comparatively dense enclosing numerous small vacuoles. Many Fungi contain color substances which are dissolved in the cell-sap and are of a quite brilliant hue. One of the most interesting classes of substances produced by Fungi is that of the ferments, including the oxidizing ferment allied to laccase. They contain also amido-substances related to lecithin ; fats ; carbohydrates, as trehalose and mannitol ; organic acids, as oxalic, tartaric, malic, etc. ; and calcium oxalate may be present in some cases. Reproduction in the Fungi is chiefly by means of asexual spores, which arise in two ways. In the one case they are devel- oped in a special cell or sporangium at the end of a mycelial thread and are known as endospores. In the other case they arise on special hyph^e, or directly from the mycelium, and are known as ExosPORES or conidia. There are also several modifications of these two types of spores, which may be referred to later. Groups of Fungi. — There are four principal groups of Fungi : 1. Phycomycetes. 2. Basidiomycetes. 3. Ascomycetes. 4. Fungi Imperfecti. The Phycomycetes, or Algal-like Fungi, are so called because they show a certain relation to the Algae. The Ascomycetes are distinguished by having a sporangium of 42 A TEXT-BOOK OF BOTANY. a definite shape and size, which is called an ascus, and which contains a definite number of spores, which is two or some multi- ple thereof. The Basidiomycetes are the most highly developed Fungi, producing large fruit bodies, such as are seen in mushrooms, toad- stools, and puffballs. They are characterized by producing spores (basidiospores) on special hyphae. The spores are usually four in number, and the spore-producing organ is known as a basidium. The Fungi Imperfecti constitute a group of Fungi which, while having certain natural relationships with the other types already considered, yet do this so imperfectly that they are brought in a class by themselves. The complete life-cycle is not in all cases known, and future studies will probably distribute them among the other principal groups. PHYCOMYCETES : ALGA-FUNGL— The plant body of the Phycomycetes consists of a mycelium which is unsegmented, more or less thread-like and sometimes considerably branched. Reproduction takes place by means of several kinds of spores, and by reason of the production of two kinds of sexual spores they are subdivided into two important groups. These are ( i ) the Oomy- cetes, which produce oospores, and (2) Zygomycetes, which produce zygospores. Saprolegnia. — Probably one of the best representatives of the Oomycetes is the group of water molds known as Saproleg- nia, which are aquatic in their habits and are both parasitic and saprophytic, occurring on living fish, insects, crayfish and decay- ing plants and animals as well. The plant body consists of a mycelium which may be simple or branched, sometimes forming a dense mass (Fig. 21, A). Like the alga Vaucheria, it produces both swarm spores (zoospores) and oospores. The swarm spores (Fig. 21, B, C) are produced in sporangia formed by the pro- duction of a partition wall at the end of a hypha. The sporangia are either cylindrical or spherical, and contain numerous zoospores which have two cilia at one end. These spores are peculiar in that after their escape from the sporangium they swim about, then come to rest and take on a wall, after which resting period they develop two cilia on the side, again move about, and germi- nate when they find a suitable host. PRINCIPAL GROUPS OF PLANTS. 43 The oogonia and antheridia (Fig. 21, D-F ) are also formed at the ends of hyph?e. The oogonia are usually spherical and the wall contains a number of small pores. The contents, which arc at first more or less uniform, later develop egg-cells, of which there may be as many as fifty in a single oogonium. The anthc- ridium is more or less cylindrical and contains a somewhat uni- FiG. 21. Species of Saprolegnia: A, mycelium growing out from and sunounding a dead house-fly in a water culture; B, C, sporangia with biciliate swarm spores; D, a num- ber of oogonia containing oospheres; E. F. oogonia and antheridia, in F the tube of the antheridium having penetrated the oogonium.— A-C, after Thuret; D-F, after De Bary. form mass of protoplasm. The antheridium bends toward the oogonium and comes in contact with it, but apparently does not in all cases penetrate it. Nevertheless the egg-cells develop walls and become resting oospores. In Peronospora, one of the Oomycetes, the antheridium (Fig. 22, n) develops a tube which pierces the wall of the 44 A TEXT-BOOK OF BOTANY. oogonium (Fig. 22, 0); the contents unite with the egg-cell, after which a heavy membrane develops, forming an oospore, which germinates when it finds a suitable host. The plants belonging to Peronospora as well as related genera are destruc- FiG. 22. A. Cystopus candidus; B, Peronospora calotheca. Mycelia (w) with haustoria penetrating cells (z) of hosts. C, Oospore formation in Peronospora: o, oogonium; n, anthe- ridium. At the left the antheridium is in contact with oogonium; the next stage shows the antheridium penetrating oogonium and discharging its contents; at the right the resulting oospore is shown. — After De Bary. tive to many cultivated plants, constituting mildews or blights, as those occurring on the leaves of hyoscyamus, tobacco, anthe- mis, matricaria, aconite, grape vine, lima bean, potato, etc. The group has received the name " downy mildews " because of the PRINCIPAL GROUPS OF PLANTS. 45 fact that the conidiophores rise to the surface of the leaves where the spores are discharged, forming powdery patches. Black Mold. — A common example of the Zygomycetes is furnished by the " black mold," Mucor Mucedo. The mycelium Fig. 23. B, richly branching mycelium (m) of the mold Phycomyces nitens showing upright hyphae bearing sporangia (g). A, C, D, the common black mold Mucor Mucedo. A, sporangium with columella; C, germination of zygospore (z), with formation of hypha (k), and sporangium (g); D, earliest stages in the development of a zygospore, the hyphal branches (b) showing adjoining ends (a) cut ofiF by cross walls. — After Sachs. of this plant is coenocytic, thread-like, very much branched, and profusely developed, much like that of Phycomyces nitens (Fig. 23, B). This mold is widely distributed, causing trouble in the spoiling of many sugar- and starch-containing substances in the household, including preserves, syrups, fruits, etc. In fact, a 46 A TEXT-BOOK OF BOTANY. number of species of Mucor have the power of inducing alcoholic fermentation in glucose-containing solutions. They are also commonly found in many aqueous solutions of inorganic chemicals as well as organic substances. Asexual spores are formed at the ends of hyphae which rise into the air. The sporangia are spherical and are cut off from the hyphae by means of a transverse wall which projects upward into the sporangium and which is techni- cally known as the columella (Fig. 23, A). The contents by Fig. 24. Peziza confluens showing stages in the development of ascospores. In the youngest asci (m, r) there is only one nucleus; this divides into two (s); the division is repeated, so that there are 4 nuclei in (t) and 8 in (n). These surround themselves with protoplasm and a cell- wall (v, w), but the protoplasm of the mother cell or ascus is not entirely used up. — After De Bary. simultaneous division form numerous i -celled spores, which are discharged by the bursting of the sporangium wall and distributed by air-currents or the wind. As the name of the group to which this plant belongs indicates, it also produces zygospores (Fig. 23, D). These are formed by hyphal branches which ascend from the substratum. The ends of two branches come together, a transverse wall is formed in each branch, the walls in contact are absorbed, the contents unite, and a spore is formed with PRINCIPAL GROUPS OF PLANTS. 47 three membranes, two belonging to the spore proper and the third being formed by the united hyphse. As would be expected, these spores are quite resistant, being able to withstand unfavorable conditions, and germinate (Fig. 23, C) only after a period of rest. ASCOMYCETES. — The Ascomycetes are distinguished for the most part, like the other higher Fungi, in having a septate mycelium, i.e., one cellular in structure, and in producing asci Fig. 25. Species of Saccharomyces (Yeasts). A, 5. cerevisioe or beer yeast; B, 5. Pastorianus; C, 5. glomeralus; D. 5. Piculalus: a, vegetative cells reproducing by budding; b, formation of ascospores. — After Reesz. (sacs), which latter are formed at the ends of the branches of the mycelia. Two main sub-groups are recognized, the one producing an indefinite number of spores m asci which are not well developed, and known as the Heaiiasci ; the other producing a definite number of spores, which number is characteristic for each species, in a well-developed ascus, and known as the Euasci. In the latter group the spores arise by successive divisions of the primary nucleus into two, as shown in Peniza condiicns (Fig. 24). Yeasts.— The simplest of the Ascomycetes is the sub-group known as the Saccharomyces, or Yeasts. The Yeasts do not produce a mycelium, but the plant body consists of a single cell, or a chain of cells, and multiplies by a peculiar process known as '' yeast budding" (Fig. 25, a). From either end of the cell a wart-like process develops, which enlarges until about the size 48 A TEXT-BOOK OF BOTANY. of the original cell, from which it is then separated by the forma- tion of a transverse wall. The cells are spherical, ellipsoidal, or egg-shaped, and in some cases somewhat elongated and hypha- like. In the protoplasm are one or more large vacuoles. In certain of the cells, which may be considered to be asci, two to eight spherical or ellipsoidal spores are produced (Fig. 26). There are a number of different species of Yeasts, some of which Fig. 26. Formation of ascospores in a number of diflFerent species of Yeasts, i, Sac- charomyces cerevisia; 2, S. Pastorianus; 3, 5. inter medius; 4, 5". validus. — After Hansen. are cultivated ; and these latter are of great economic importance on account of their property of inducing alcoholic fermentation. They are also of use in the making of bread, changing the carbo- hydrates in part into carbon dioxide and alcohol, both of which are driven off in the baking. The property of yeast causing the fermentation of a solution PRINCIPAL GROUPS OF PLANTS. 49 of sugar whereby alcohol is formed, was for a long time supposed to be due to the presence of the living yeast cell or to the action of living yeast protoplasm, and hence fermentation brought about by living organisms was distinguished from those fermentative processes where distinct principles such as diastase were involved ; the former being known as " organized " ferments, while the latter were referred to as " unorganized " ferments. Biichner obtained from freshly expressed yeast a nitrogenous substance capable of changing solutions of cane sugar or glucose into alcohol and carbon dioxide. This principle he termed zymase, and it has all of the properties of an enzyme or ferment and behaves exactly as the living yeast cell in a sugar solution. In the living yeast plant zymase is continually being formed and decomposes the sugar which has diffused into the cell. Yeasts are used in the treatment of certain skin diseases, their action being attributed to a fatty substance, ceridine. Other principles found in yeasts as well as extracts are used in the treatment of cancer. Under the name of Xerase a mixture is marketed consisting of 150 parts of dried beer yeast, 20 parts of dextrose, 125 parts of white clay or aluminum silicate, and 3 parts of a mixture of nutritive salts. It is used in the treatment of putrid wounds, ulcers, etc. The ginger beer plant, which is used in England for making a beverage known as ginger beer, consists of a yeast {Saccliaro- myces pyriformis) and a bacteria (Bacterium venniforme). These two organisms live in a somewhat symbiotic relationship, the yeast changing the sugar into alcohol and the bacteria developing lactic acid (see Technical Mycology, by Lafar). Green and Yellow Mildews. — To the Ascomycetes also be- long the green and yellow Mildews, Penicillium and Aspergillus, so common in the household, the dairy, and the granary. These plants produce profusely branching mycelia which form patches upon or just under the surface of the materials upon which they grow. These areas become soft and spongy and are always white at first. After a time hyphal branches, which are more or less flask-shaped, rise above the substratum, and by a process of division at the end of the branch, or conidiophore, a spore called 4 50 A TEXT-BOOK OF BOTANY. a conidiospore is formed (Fig. 2^, A; Fig. 28, A). The process of division at the end of the conidiophore continues from below until a chain of conidiospores is formed. The conidiophore fre- quently branches, so that a fan-like series or group of conidia or Fig. 27. Penicillium, a green mildew. A, richly branching mycelium with conidio- phores; B, enlarged view of conidiophore showing chains of conidia; C, D, E, F, successive stages in the development of a perithecium; G, H, J, development of asci; K, groups of asci containing from 4 to 8 ascospores; L, ascospores seen from the side and showing char- acteristic markings. — After Brefeld. conidiospores is produced (Fig. 2y, B ; Fig. 28, A). The conidia are usually some shade of green, but finally they may become more or less brown. They are thin-walled, quite small, and so light that they float freely in the air. If a colony is inhaled it gives PRINCIPAL GROUPS OF PLANTS. the sensation commonly called the "smell of mold." They are cap- able of germinating on almost everything, as old shoes, old pa])er, as well as on bread and other articles of the household. They may occur on "moldy drugs," and in pharmaceutical preparations, as syrups and infusions. Some of the molds produce citric and ox- alic acids (Amer. Jour. Pharm., 1916, pp. 125 and 337). Aspergillus (Fig. 28) is distinguished from Penicillium (Fig. Fig. 28. Aspergillus, a yellow mildew. A, conidiophore with enlarged, more or less spherical end, from which the fan-like series of chains of conidia arise; B-E, successive stages in the development of perithecium; F, section through a nearly ripe perithecium; G, groups of young asci; H, a ripe ascus with 8 spores. — A, after Kny; B-H, after De Bary. 27) by the fact that the upper end of the hyphal branch or conidio- phore is somewhat enlarged and more or less spherical. In addition to the conidiospores these Fungi sometimes produce in the fall of the year, particularly when grown upon bread, asci fruits (Fig. 27, C-F ; Fig. 28, B-E^ . In this case two fertile ini- tial hyphje wind themselves around each other, after which they become surrounded with sterile branches which form a kind of 52 A TEXT-BOOK OF BOTANY. loose tissue, more or less cellular in structure, that finally develops into a yellowish leathery wall. This body, which may be regarded as a closed ascocarp, is known as a perithecium (Fig. 2^, F ; Fig. 28, F), As a result of the conjugation of the fertile cells, asci (Fig. 27, G, H, J ; Fig. 28, G, H) develop within the perithecium, which are more or less spherical or ellipsoidal and contain from four to eight spores (ascospores) (Fig. 27, K; Fig. 28, H). After maturity the cellular tissue around the asci dries up and dis- integrates, the walls of the asci dissolve, and the ascospores are liberated from the perithecium by slight pressure. The spores lie over winter and then germinate, producing a mycelium from which conidia first develop and afterwards the perithecia, thus repeating the life history of the plant. Ergot. — Another Ascomycete of special interest is the fungus known as Ergot (Claviceps purpurea). The spores of this fungus germinate on the flowers of certain grasses. The myce- lium penetrates the walls of the ovary, absorbing the nutriment. After a time the mycelium develops on the surface, and from this short conidiophores arise bearing small ovoid conidia (con- idiospores) (Fig. 29. A). The mycelium secretes a sweet fluid, the so-called honey dew which attracts insects, and thus the conidia are carried to other plants. As the conidia are capable of immediate germination the so-called " ergot disease " rapidly spreads during the flowering season of the host plants. After the formation of conidia ceases, the mycelium forms a dense mass which is surrounded by a dark layer, and this, if developed upon rye, constitutes the ergot grains (Fig. 29, B) used in medicine, these grains being a number of times larger than the rye grains which they replace. The mycelial tissues connected with the host plant die, and the ergot drops to the ground. At this stage the ergot mass is more or less cellular in structure and is known as the scLEROTiuM. It is quitc resistant and usually remains dormant until the following spring when the grasses are in flower again. The sclerotium then shows signs of renewed activity by the de- velopment of small, reddish, spherical bodies with a fair-sized stalk (Fig. 29, C). Within the periphery of these spherical heads are produced flask-shaped perithecia or ascocarps (Fig. 29, D) PRINCIPAL GROUPS OF PLANTS. 53 F,c ., a.,iceps purpurea. A. mycelium daveloij^ngc„„W^^^ like ascospore.— A, alter tsreieiu, the wind to the flowers of certain of the grasses, as already stated, and The hfe history or cycle of growth beg.ns agam. 54 A TEXT-BOOK OF BOTANY. Chestnut Bark Disease is caused by a fungus parasite known as Diaporthe parasitica Murrill, and is said to very closely re- semble the parasite found in Italy, EndotJiia radicalis. This fungus has been the cause of very great destruction of chestnut trees in the eastern United States. When any of the spores of this fungus gain entrance into a wound on any part of the tree, thread-like mycelia are developed in the inner layers of the bark, and these spread concentrically until they girdle the trunk or ;^ ife-J^ Fig. 30. Large Chestnut tree partly killed by the bark disease. Note branches in the center either killed or bearing dwarfed leaves, and the other larger branches still unaffected. — From photograph by Haven Metcalf. limb, so that if it happens that the trunk is affected the entire tree may die within the year, while if it is the smaller branches which are attacked, only those parts beyond the point of infection are killed, while the remainder of the tree will survive for some years (Fig. 30). When the bark is attacked by the fungus it shows minute, more or less crater-like spots of a yellowish-orange or reddish-brown PRINCIPAL GROUPS OF PLANTS 55 color which are pustules of the fruiting fungus. These pustules produce mostly winter spores (ascospores) , although occasionally a long strip of summer spores (conidia) are also produced (Figs. 31 and 32). Fig. 31. Typical appearance of branches of Chestnut tree affected with chestnut bUght. At left, bark showing pustules of the parasitic fungus bearing winter spores. At right, the diseased bark showing pustules and form of discharge of summer spores in damp weather. — ^From photograph by Haven Metcalf. The control of the disease over large districts consists mainly in destroying the affected trees and carefully burning the rubbish. 56 A TEXT-BOOK OF BOTANY. Single trees are treated by removing the affected branches and painting over the cut ends with coal tar to prevent reinfection. For further details on this fungus consult: Murrill, '' A New Chestnut Disease," Torreya, Sept., 1906; Farmers' Bulletin 467, U. S. Department of Agriculture; Metcalf, '* Diseases of the Chestnut and Other Trees," Trans. Mass. Hort. Soc, August, Fig. 32, Chestnut-blight disease, which occurs in small yellowish pustules the size of a pin head. A, section of pustule showing perithecia; B, asci with sporidia; a, usual form; b, form rarely found; C, sporidia; D, summer spores. — After Murrill. 1912; Farlow, "Fungus of the Chestnut-Tree Blight," Science, May 10, 191 2. Basidiomycetes. — The Basidiomycetes are the most highly organized of the Fungi. The mycelium consists of white branch- ing threads and is usually concealed in the substratum. In the cultivation of the edible mushrooms propagation is by means of the mycelium, which is known commercially as " spawn." It is recognized, however, that mushrooms can not be propagated in PRINCIPAL GROUPS OF PLANTS. 57 this way exclusively for more than two or three years. The my- celium is really the plant body, and the part which rises above the surface and is commonly regarded as the toadstool or mushroom (Figs. 33 to 37) is a fruit branch, or spore-producing organ. When these branches first make their appearance they are in the form of small solid bodies known as " buttons " (Fig. 33, I-V). Fig. 33. Agaricus campestris, the common edible mushroom, showing at A on the left mycelium (m) and development of buttons or young mushrooms; I to V, longitudinal sections showing successive stages in development of fruit body; m, mycelium; st, stipe; h, portion between veil (v) and spore-bearing portion (1). The illustration to the right (A, B, C) shows the structure of the hymenium in different degrees of magnification: A, section through portion of pileus showing five of the gills; B, section of a gill somewhat magnified; C, section of gill still more magnified and showing sterile cells or paraphyses (q), and the fertile cells or basidia (s), from each of which arise two basidiosporea. — After Sachs. As growth proceeds these bodies differentiate into a stalk-like portion known as the stipe (Fig. 33, st), which is directly con- nected with the mycelium, and an umbrella-like portion borne at the summit of the stalk, called a pileus, which at first is closed down over the stalk, but later expands or opens more or less widely according to the species. On the under surface of the pileus, known as the hymenium, the spores are borne (Fig. 33, 58 A TEXT-BOOK OF BOTAXY. Fig. 34. Some common edible mushrooms and a common poisonous one. The fol- lowing are edible: i, Common Field mushroom (Agaricus campestris); 3, Clavaria flava, young plant; 6, Puffball (Lycoperdon cyathiforme); 4, Morel (Morchella esculenta); 5. Chanterelle {Cayitharellns cibarius); 7. Fairy-ring Fungus {Marasmius oreades). Only one poisonous species is shown, namely, 2, the deadly Agaric (^Amanita phalloides). — Adapted from Farlow. PRINCIPAL GROUPS OF PLANTS. 59 A, B, C). In some cases the under surface is composed of a series of narrow, radiating, knife-like plates, or gills, as in the common edible mushroom Agaricus. On the surface of the gills the basidia or spore-bearing organs arise. The basidia are somewhat swollen terminal cells of the closely arranged hyphse composing the gills, which bear a group of spores on short stalks (Fig. 33, C). Both the basidia and spores (basidio-spores) are of a characteristic size and number for the different species. Several types of Basidiomycetes are usually recognized, de- pending on the manner in which the spores are borne. 1. T^e Gill Fungi (Agaricaceae), in which the spores are borne on plates or gills which radiate from the stem to the edge of the cap. 2. The Pore Fungi (Polyporaceae), in which the spores are borne in tubes or pits opening by pores rather than on gills. 3. The Coral Fungi (Clavariacea^), in which the Fungi are coral-like or leaf-like, the surface of the cap or its branches being smooth. 4. The Leather Fungi (Thelephoracese), in which the spore- bearing surface is smooth or slightly wrinkled. The texture is usually leathery or papery. 5. The Jelly Fungi (Tremellaceae), in which the fruiting sur- face is smooth and the cap is more or less jelly-like when wet. 6. The Puff' Balls (Lycoperdaceae), in which the cap is a closed ball which breaks open at maturity to release the enclosed spores. 7. The Carrion Fungi or Stink-horn Fungi (Phallaceae) re- semble the puffballs when young, but are ruptured longitudinally, the spores thereby being exposed on the top as a gelatinous mass. Of these seven groups the Gill Fungi are the commonest, and one or two types will be considered, namely, the common edible mushroom and two of the poisonous group, Amanita. Edible Fungi. — Agaricus campestris (common mushroom) (Figs. 33 and 34) is practically the only edible species cultivated in this country. The plant grows wild in open grassy fields dur- ing August and September. It is not found in the mountains to any extent, and is never found in the woods or on trees or fallen trunks. The color of the stipe and the upper surface of the 6o A TEXT-BOOK OF BOTANY. Fig -xk A decaying tree trunk showing the cause of the death of the tree by aVnear'a^nce of the^e?eral fungi (probably L./>/..a Amencana). It is not unusua '^'%'nTt^'eTs''show\rgTgnT'ordiseaTe"and-;fin even dying, and it not until For some years the death of the tree that the mature fungus makes its appearance. I'or some yearb e mycelium of the fungus has been working its way nito the tissues not only of tSe ffi bu^of the wood sapping it of its vitality. The fungus finally produces its the bark but of the wood, sappi..^ .u u. ..^ ,..^...^. --- -. - - :. -.„,,„v, the fruit with spores, the latter being scattered by either the wind or through the asency of birds, are carried to other trees and find entrance into rounds where they germinate and repeat their destruction.— From a photograph by iroth. PRINCIPAL GROUPS OF PLANTS. 6i pileus varies from whitish to a drab color, but the color of the gills is at first pinkish and then of a brownish-purple, which is an important character, the color being due to the spores. The stipe is cylindrical and solid, and a little more than half way up is furnished with a membranous band known as the ring. There are no appendages at the base of the stipe, which appears to rise IHJ^HPP ■ ■M ^^ H 1 1 '> ' ■> . ^ ■■■ iP'' i ^3«.f * - 'I 1 H ^M H 1 ^- ^S^tK^^'^^ ''i^ 1 1 1 Fig. 36. Edible Boletus (Boletus edulis), an excellent edible mushroom found in woods and openings in summer and autumn. The cap is 8 to 15 cm. wide, grayish-, yellowish-, or brownish-red, sometimes paler toward the edge, smooth, and more or less convex; flesh whitish or yellowish, or somewhat reddish just beneath the skin; stem white, stout, and often bulbous. — After Atkinson, "Studies of American Fungi." directly out of the ground. Before the pileus is fully expanded a veil extends from its border to the stipe, which when ruptured leaves a portion attached to the stipe, and it is this which consti- tutes the ring. The ring shrinks more or less in older specimens. but usually leaves a mark indicating where it has been formed. Poisonous Fungi. — There are two of the poisonous group of Fungi which are very common and which have some resem- 62 A TEXT-BOOK OF BOTANY. blance to the edible mushroojn just described, namely, the fly agaric (Amanita miiscaria) (Fig. 38) and the deadly agaric {Amanita phalloides) (Fig. 34) . The fly agaric, wliile more abun- dant in some localities than the common edible mushroom, is Fig. 37. Pale Lenzites (Lenzites betulina) , a non-edible lungus common on trunks and stumps throughout the year. The cap is whitish, corky, more or less densely hairy, and marked by concentric grooves; the stem is lacking and the gills are whitish, more or less branched and united. — From monograph on Minnesota Plant Diseases by E. M. Freeman. seldom found in grassy pastures, but more generally in poor soil, especially in groves of coniferous trees. It occurs singly and not in groups. The gills are always white ; the stipe is white, hollow, and provided with a ring at the top, and the base is bulbous, hav- ing fringy scales at the lower part. The pileus is yellow or orange PRINCIPAL GROUPS OF PLAN TS. Zzrr'^' ^--^"'^ Vd,o^"::\:s r-j ^-di. .ushroo.. The cap is b^^ht angular fragments of the vojva- the stemTf.f . 3^' ^°"ghened with many thick white '-^^fS several concentric scaly^ingslfn ""e burh: Zul' ''^'^' '^"^^°"^' ^"^ hollow; ^ol va This IS frequent in woodland, forest or cllarin.fr;^' ! °'. t°"ching. white or yellowish. -From monograph on Minnesota Mushroom! by Fri5"eri E ct '"'^ " ^""^'^ ^°''°°°'*' 64 A TEXT-BOOK OF BOTANY. and sometimes reddish ; the surface is smooth, with prominent, angular, warty scales, which can be easily scraped off. The deadly agaric (Fig. 34, illus. 2) somewhat resembles the fly agaric and also dift'ers from the common mushroom in not usually growing in pastures. It occurs singly, but not in groups, in woods and borders of fields. The gills and stipe are white, the latter, when young, having a number of mycelial threads running through it. The base is quite bulbous, the upper part of the bulb having a sac-like membrane called the volva. The pileus may vary from any shade of dull yellow to olive, although some- times it is shiny and white. While it does not possess the warty scales found in the fly agaric, it has occasionally a few mem- branous patches. The Toxic Principles in. Poisonous Fungi. — The deadly agaric {Amanita phalloides) is the cause of the greatest number of cases of mushroom poisoning. According to Abel and Ford, it contains two toxic principles: (i) Amanita-hemolysin, a blood- laking principle, which is a very sensitive glucoside, — that is, pre- cipitated by alcohol, destroyed by heating to 70° C. and by the action of digestive ferments; (2) Amanita-toxin, which is soluble in alcohol, is not destroyed by the action of heat or ferments. The latter principle is the important poisonous prin- ciple in mushroom poisoning and is probably the most toxic principle known, 0.4 of a milligramme killing a guinea pig within 24 hours. " The majority of individuals poisoned by the ' deadly amanita ' die, but recovery is not impossible when small amounts of the fungus are eaten, especially if the stomach be very promptly emptied, either naturally or artificially.'' The fly agaric (Amanita muscaria) owes its toxicity to mus- carine, an alcohol-soluble crystalline substance. It is supposed by Ford that the fly agaric may contain another poisonous constit- uent. In cases of poisoning atropine has been successfully ad- ministered hypodermically in doses of y^o to 5^0 of a grain. It is stated that the A. muscaria, used by the peasants of the Caucasus in the preparation of an intoxicating beverage, is deficient in muscarine. The question as to whether the ordinary edible mushrooms, as distinguished from the poisonous toadstools, may not in cer- PRINCIPAL GROUPS OF PLANTS. 65 tain localities or at certain periods of the year be the cause of fatal intoxication is answered by Ford in the negative. He states '{Science, 30, p. 105, July 23, 1909) that there are no authentic cases of poisoning from the black or brown spored agarics, although old and badly decomposed specimens may cause transient illness. Economic Uses of Fungi. — A large number of the Fungi, particularly of the Basidiomycetes, are used for food. There are, however, only a few of these which enter the market. These are derived chiefly from Agaricus campestris (Figs. 33 and 34) and Agaricus arvensis, although some other species of Agaricus as well as Morchella esculenta (Fig. 34, illus. 4) furnish excellent products and are cultivated to a limited extent. The " truffles " of the market are tuber-like masses formed under ground, which consist of the ascocarps of certain Tuberaceae, one of the sub- groups of the Ascomycetes, and which are used as a condiment and sometimes roasted like potatoes. Tuckahoe or *' Indian bread " is also produced under ground and consists apparently of the fungus Pachyma Cocos and the roots of Liquidambar, the tissues of which have been changed into a compound resembling pectic acid by the fungus. Quite a number of Fungi have been used in medicine, as Claviceps purpurea (Fig. 29), Polyporus officinalis and other species, and various species of Lycoperdon. A number of species are used in making surgeon's agaric (Fungus chirurgorum) formerly used as a haemostatic, including Lycoper- don Bovista and Polyporus fomentarius. Many of them yield very toxic principles, as ( i ) several species of Amanita which contain several toxic principles; (2) Lactarius piperatus and others which yield highly poisonous resinous principles. Other uses of Fungi have been mentioned under the several groups. UsTiLAGiNE.E and Uredine.i:. — There are two groups of Fungi of considerable economic interest which by some writers are classed by themselves, and by others placed with the Basidio- mycetes. These are the Ustilaginese, or Smut Fungi, and the Uredineae, or Rust Fungi. The Smut Fungi are parasitic on higher plants. The myce- lium penetrates the tissues of the host, but does not seem to cause either disease or malformation of the plant. Injury to the 66 A TEXT-BOOK OF BOTANY. host results only after the development of resting spores. The mycelia are hyaline, more or less branched, and finally become septate. They send short branches, called haustoria, into the cells of the host, from which they obtain nourishment. Eventu- ally the mycelium becomes much branched, compact and more or less gelatinous through a transformation of the hyphal walls, forming gall-like swellings or blisters on the host. Spores are formed within this gelatinous mass at the ends of the branches Fig. 39. Corn smut {Ustilago Maydis) showing several gall-like masses of smut full of spores. of the mycelium. At a later stage the smut loses its gelatinous character, the mass breaks up, and the spores are freed and dis- tributed as a dry, dusty powder. The spores (primary conidia) are somewhat spherical or ellipsoidal, and are generally separate, but are sometimes united into a mass forming the so-called " spore balls." These are resting spores and upon germination (Fig. 40) produce a promycelium or basidium which becomes septate and from each cell of which conidia called sporidia arise. The sporidia are formed in succession one after another and the process con- PRINCIPAL GROUPS OF PLAXTS. 67 tinues for some time. On germination they bud like yeast, form- ing new conidia, or when nutrition is not abundant they may form a mycelium, which is usually the case when they germinate on a host plant. Corn Smut. — One of the Smut Fungi, namely, Ustilago Maydis, which develops on Indian corn (Fig. 39), is used in medi- 00% o © Fig. 40. Spores of various Smuts. I, Ustilago loyigissima growing on the reed meadow- grass {Panicularia americana); 2, Ustilago Maydis from Indian corn {Zea Mays)\ 3, Ustilago Oxalidis on the yellow wood-sorrel {Oxalis stricta) ; 4, Ustilago utriculosa on the Pennsyl- vania persicaria {Polygonum pennsylvanicum). Fig.- 40a. Germination of spores. 5, Ustilago utriculosa, in water, showing promy- celium and sporidia; 6, Doassansia opaca from the broad-leaved arrow-head {Sagittaria latifolia) in water, showing promycelium, sporidia, and secondary sporidia which are falling off; 7, Ustilago Avenos from oat {Avena sativa) in horse dung, showing promycelium, and lateral "infection threads" or hyphae; 8, germination of a sporidium of Ustilago Sorghi into an infection thread; 9, small portion of a group of sporidia developed from promycelium of Tolyposporium Eriocauli on potato agar; 10, cross-section of epicotyl of broom-corn infected by Ustilago Sorghi showing mycelium ramifying through parenchyma cells of the cortex. — After Clinton. cine. It forms rather large gall-like masses on all parts of the plant, including the root, stem and leaves, and both staminate and pistillate flowers. The spores (Fig. 40) are at first a dark olive- green, but on maturity are dark brown. They are sub-spherical, have prominent spines, and vary from 8 to 15 microns in diameter. They do not germinate at once, but on keeping them for six 68 A TEXT-BOOK OF BOTANY. months to a year they germinate readily on a culture medium of potato, and retain their power of germination for years Rust Fungi. — The Rust Fungi are parasitic on higher plants Fig. 41. Wheat TXist (Puccinia graminis). A, teleutospore or winter spore germinating and giving rise to a promycelium (p) and sporidia (s) ; B, a few leaves of barberry attacked by sporidia which give rise to the aecidia; C, transverse section through barberry leaf show- ing three cup-like receptacles (aecidia) on the lower surface of the leaf containing per- pendicular rows of conidia (aecidiospores) ; D, germinating aecidiospore on wheat; E, wheat plant attacked by aecidiospores as shown by the elongated blotches on the leaves; F, cross section of leaf of wheat showing on the upper surface the rust spores which are breaking through the epidermal layer (r) ; G, summer spores (uredospores) ; H, teleutospores or winter spores formed on wheat leaf. — After Dodel-Port. and produce a thread-like branching, cellular mycelium, which develops in the tissues of the host. They differ especially from the other Fungi in producing resting spores known as teleutospores. PRINCIPAL GROUPS OF PLANTS. 69 These spores consist of one or more cells surrounded by a thick black wall, and they produce the " black rust " seen on foliage at the end of the season. Wheat Rust. — The most important member of the Rust Fungi is Puccinia, of which there are a large number of species that are destructive to economic plants, as wheat, plum, cherry, red cur- rant, etc. The one whose life history has been best studied is the wheat rust {Puccinia graminis), which requires two dilYerent plants to complete its life history, namely, wheat and barberry. The Teleutospores, or '* winter spores" (Fig. 41, //), as they are called, because of their carrying the life of the plant over the winter season, consist of two cells. These spores exist on the leaves and stems of wheat over winter, and in the spring they ger- minate (Fig. 41, A). From each cell a mycelium (promycelium or basidium) consisting of two to four cells arises (Fig. 41, A, p), and from the tip of each branch of the promycelium a spore known as a sporidium develops (Fig. 41, A, s). The Sporidia are scattered by the wind, and when they fall on the barberry leaves (Fig. 41, B) they germinate, producing a dense mass or mycelium which penetrates into the tissues of the host. Sooner or later, just within the under surface of the leaf, there is formed a more or less spherical, dense mass, which grows outward, breaking through the surface, forming a cup-like re- ceptacle known as an secidium (Fig. 41, C). The JEcidis., or cluster cups, are orange or yellow and are filled with perpendicular rows or chains of spores which arise from the basidium-like mycelium below. The spores, which have received the name Aicidiosporcs, are somewhat spherical or polyhedral, and contain a reddish-yellow oil. They are scattered by the wind and, falling upon the wheat plant (Fig. 41, E) , germinate immediately, form- ing a dense mycelium. At first it produces what is known as a " Summer spore," or Uredospore (Fig. 41, G), giving rise to the reddish-brown spots and stripes on the leaves and stalks of the wheat plant. The Uredospores are i -celled, and are carried by the wind to other wheat plants, thus rapidly spreading the disease. The Uredospores arise in much the same way as the Teleuto- spores (Fig. 41, //), which form brown patches later in the sea- son, and which have been already considered. The Teleutospores 70 A TEXT-BOOK OF BOTANY. last over winter on the old wheat plant, and in the spring begin again the life-cycle of the rust. The plant which results from the germination of a teleutospore gives rise to sporidia, which are carried to the barberry leaves where secidiospores are pro- duced. The latter are then carried to growing wheat, forming first uredospores and later teleutospores. It should be remembered that these are all asexual spores. In regions where there are no barberry plants to act as host the aecidiospore stage is omitted. The Fungi Imperfecti. — The miscellaneous fungi included in this group are of importance because of the great damage which they cause to agricultural crops. The potato scab is an especially destructive pest in New England and in Canada. The scab not only develops on the growing tubers in the soil, but can be spread from a few affected potatoes to a whole bin of clean ones if they come in contact with them. Prevention of this disease usually consists in disinfecting the tubers which are used for seed so as not to carry the minute organisms into the soil. A disease affecting the leaves of the potato and thereby destroy- ing the crop is due to a fungus whose spores, settling on the leaves, germinate and penetrate to the interior through the stomata, finally weakening or killing the plant. Some of the other important forms produce a pink mold on apples, scabs on peaches and other fruits, mold on onions and other garden crops. The blight of ginseng and the blight of cotton, the dry rot of various vegetables and the blotches on many of our common fruits can be traced to the development of these fungi. The study of these forms is a very difficult one, and re- searches are constantly being carried on at the government experi- ment stations, as well as by individual workers. For a description of these forms, as well as many other harmful fungi, consult '' Fungous Diseases of Plants," by Duggar. Detection of Fungus in Host. — Unless special means are employed, it is ofttimes rather difficult to trace the mycelial of the fungus in among the cells of the host plant. Vaughan (Annals of the Missouri Botanical Garden, 1914, p. 241 ) has used the stain known as " Pianeze Illb " in differentiation of the fungus from the plant substratum. The host tissue stains green and the my- celium a deep pink. This stain, devised by Dr. Pianeze for the PRINCIPAL GROUPS OF PLANTS. 71 study of cancer tissue, is made up as follows : Malachite green, 0.50 Gm. ; acid fuchsin, o.io Gm. ; " Martius gelb," o.oi Gm. ; water distilled, 150.00 c.c. ; alcohol (95 per cent.), 50.00 c.c. For use with plant tissues the procedure is as follows : Wash in water or alcohol, stain in the undiluted mixture 15 to 45 minutes, remove excess stain in water, and decolorize in 95 per cent, alcohol to which a few drops of hydrochloric acid have been added. For per- manent mounts, clear with a carbol-turpentine mixture, remove clearing solution, and mount in balsam. This stain is also valuable for staining spores which have been allowed to germinate on the surfaces of leaves. In such cases the killing and tissue-clearing mixture proposed by Duggar is recommended, viz., consisting of equal parts of glacial acetic acid and alcohol. In the study of the rusts, the best results are obtained by the use of Durand's combination of Delafield's hsema- toxylin and eosin (Phytopathology, 191 1, p. 129). LICHENS. General Characters. — The Lichens are a peculiar group of plants in that an individual lichen consists of both an alga called a GONiDiUM and a fungus. These are so intimately associated that they appear to be mutually beneficial, and such a relation is known as SYMBIOSIS (Fig. 42). The Algae which may be thus associated in the Lichens are those members of the Blue and Green Algae which grow in damp places, as Protococcus, Nostoc, Lyngbya, etc (Fig. 42). The Fungi which occur in this relation belong both to the Ascomycetes and Basidiomycetes, and it is on the characters of the fruit bodies of these particular Fungi that the main divisions of Lichens are based. The Fungi, however, are not known to exist independently of the Algae with which they are associated ; that is, the mycelia of the fungi will not live for any length of time unless they come in contact with suitable algae. In its development the fungus forms a mycelium which encloses the alga, the growth of which latter is not hindered. The two organisms then continue to grow simultaneously, forming lichen patches. A section of a lichen shows a dififerentiation into several parts (Fig. 43) : a more or less compact row of cells on both surfaces forming two epidermal layers ; and an inner portion i2 A TEXT-BOOK OF BOTANY. made up of the hyphal tissue of the fungus in which the alga is em- bedded either in a single layer or throughout the mycelium. The mode of growth and branching is influenced largely by the fungus, although in some cases the alga may exert the most influence. In some cases the lichen consists of a thallus which is irregular in outline, growth taking place at no definite point, and in other cases branches which are more or less regular are formed, growth taking place at the apex. Fig. 42. Lichens showing manner of union of algae or gonidia (g) and hyphae (h) of Fungi. A, Protococcus, showing the manner in which hyphge penetrate the cell and in- fluence cell division; B, Scytonema, an alga surrounded by richly branching hyphae; C, chain of Nostoc showing hypha of fungus penetrating a large cell known as a heterocyst; D, fungal hyphae have penetrated the cells of Glceocapsa, a blue-green, unicellular alga; 'E.Chlorococcum, a reddish or yellowish alga found in Cladonia furcata, the cells of which are surrounded by the short hyphae of the fungus. — A, after Hedlund; B-E, after Bornet. The walls of the hyphae of the fungus comprising Lichens con- sist at first of pure cellulose. In older material the walls undergo more or less modification, being changed in part to starch, mucilage, or fixed oil. There may be also infiltrated among the layers of the wall calcium oxalate, the latter constituent being especially characteristic of the crustaceous Lichens. The most interesting constituents of Lichens are the coloring principles, which are mostly of an acid character and are termed Lichen-acids. . They PRINCIPAL GROUPS OF PLANTS. 73 give very striking reactions with solutions of the alkahes and solu- tions containing chlorine. The reaction with iodine solutions is also employed for diagnostic purposes ; some of the Lichens give a blue reaction, while others behave like amylo-dextrin. Groups of Lichens. — According to the manner of growth and the manner of attachment to the substratum, three principal groups of Lichens may be distinguished : namely, ( i ) Crus- taceous Lichens, where the thallus adheres closely to the stones and barks of trees and practically can not be removed without injury; (2) Foliose Lichens, or those which are more or less flattened, somewhat leaf-like and attached at different points ; (3) Fruticose Lichens, or those which are attached at a particular part of the thallus, and form diffusely branching clumps. To this latter group belong Cetraria islandica or Iceland moss (Fig. 43), which is used in medicine, Usnea barbata and the red-fruiting Cladonias which are so common. Reproduction in the Lichens takes place in several ways. In all of them there is a vegetative mode by means of what are known as soredia. These are small spherical bodies consisting of a group of algal cells, which are surrounded by a mass of hyphae, and which when cut off from the main body are able to grow. Lichens also produce spores of a number of kinds. In the largest group, the one to which Cetraria islandica (Fig. 43) belongs, the spores are found in special spherical receptacles, known as pyc- NiDiA, which are formed on the teeth of the margin of the thallus. The spores arise from the ends of hyphae at the base of the pyc- nidia and are in the nature of conidiospores. To these spores the name pycnoconidia has been applied. Cetraria also pro- duces, like many other Lichens, disk-like or cup-shaped bodies at various places on the surface of the thallus, which are known as APOTHECiA and which may be regarded as exposed or open asco- carps. The inner surface of the apothecia is lined with a number of asci as well as sterile cells, the former giving rise to ascospores. Economic Uses of Lichens. — A number of the Lichens are used in medicine, as several species of Cetraria, Fertiisaria com- munis, Physica parietina, Sticta puUnonacea, Evernia fiirfiiracca. Some of those used in medicine are also used as foods on account 74 A TEXT-BOOK OF BOTANY. of the gelatinous carbohydrate lichenin which they contain. Be- sides those given, the following may be mentioned : Cladonia rangifenna (reindeer moss), Lecanora esculenta (supposed to be the manna of the Israelites). The Lichens are, however, chiefly of interest because of the coloring principles which they contain. Fig. 43. Iceland Moss {Cetraria islandica). A-F, various forms of thalli showing apothecia (a); I, cross-section of an apothecium showing the hymenium (h), the hypothe- cium (p), the algal layer (e), the medullary layer (m), and lower or ventral surface (1); K, an ascus with eight ascospores and two paraphyses from the hymenium (h). Roccella tinctoria, Lecanora tartarea, and other species of Leca- nora, yield upon fermentation the dyes orcein and litmus, the latter of which finds such general use as an indicator in volu- metric analysis. Cudbear, a purplish-red powder, is prepared by treating the same lichens with ammonia water ; while in the prep- PRINCIPAL GROUPS OF PLANTS. 75 aration of orchil, a purplish-red pasty mass, sulphuric acid and salt are subsequently added. A number of species contain a yel- low coloring principle, as Zeora sulphurea, Zeora sordida, Lecidca geographica and Opegrapha cpigcva. ARCHEGONIATES. The two main features which distinguish the Archegoniates from the Thallophytes are the structure of the sexual organs and the distinct manner in which the peculiar phases known as alter- nation of generations are shown. The antheridium or male sexual organ is a well differentiated multicellular body which is either sunk in the adjacent tissues of the plant or is provided with a stalk. Within it are organized the sperms or spermatozoids, which are ciliate and swim freely in water. Corresponding to the oogo- nium of the Thallophytes is the archegonium or female sexual organ which gives name to the group. The archegonium is a flask-shaped cellular body consisting of a basal portion of venter, which contains a single ^gg, and a neck through which the sperms enter (Figs. 49 and 51). In the life history of this group of plants there are two gen- erations or phases of development. During one stage the arche- gonium and antheridium are developed, and this is known as the sexual generation, and as these organs give rise to gametes or sexual cells it is also spoken of as the gametophyte. By the union of the sex cells (sperm and ^gg) an oospore is formed which germinates at once within the archegonium. That portion of the plant which develops from the oospore gives rise to asexual spores, and hence this phase is called the asexual generation. It is also spoken of as the sporophyte from the fact that it gives rise to spores. These spores are in the nature of resting spores and do not germinate on the plant as does the oospore. They are distributed and on germination give rise to the gametophyte stage. In some of the Archegoniates these two phases are combined in one plant, as in the Bryophytes, whereas in other members of the group the two phases are represented by two distinct plants ; that is, the gametophyte and sporophyte become independent of each other, as in the Ferns. 76 A TEXT-BOOK OF BOTANY. The following table shows the main divisions and subdivisions of the Archegoniates : Archegoniates Bryophytes. . . . jHepaticse (Liverworts) I Musci (Mosses). Pteridophytes , Filicales (Ferns). Equisetales (Horsetails). Lycopodiales (Club Mosses) BRYOPHYTES The structure of the sexual organs in the Liverworts (Fig. 44) and Mosses (Fig. 49) is essentially the same, but the vegetative organs are more or less dissimilar. In the Liverworts the plant Fig. 44. A common moss {Funarid). A, germinating spores: v, vacuole; w, root- hair; s, exospore. B, protonema about three weeks after germination: h, procumbent primary shoot; b, ascending branch of Umited growth; K, bud or rudiment of a leaf -bearing axis with root-hair (w). — After Sachs. body or thallus lies more or less close to the substratum or rises somewhat obliquely, whereas in the Mosses the part we designate as the plant is in all cases an upright leafy branch. The moss plant is said to have a radial structure from the fact that the leaves radiate from a central axis, while in the Liverworts the thallus IS dorsiventral ; that is, as a result of its habits of growth, it is characterized by having a distinct upper and lower surface. PRINCIPAL GROUPS OF PLANTS. ^-^ The Life History of this group of plants may probably be best illustrated by following that of a moss plant. Beginning with the germination of an asexual spore which is microscopic in size and which germinates on damp earth, there is produced an Fig. 45. A common moss (Polytrichum gracile). A, showing leafy branches (gameto- phores) two of which bear sporogonia, a detached sporogonium (sporophyte) with sporan- gium from which the calyptra (ca) has been detached. B, longitudinal section through a nearly lipe sporangium showing columella (o), the elongated area of sporogenous tissue (archesporium) on either side, annulus (n), peristome (p), lid or operculum (u); C, trans- verse section of sporangium showing columella in center and dark layer of sporogenous tissue (archesporium); D, ripe sporangium (capsule) showing the escape of spores after detachment of lid; E, ripe spore containing large oil globules; F. ruptured spore showing seoarated protoplasm and oil globules; G, two germinating spores 14 days after being sown, showing beginning of protonema in which are a number of ellipsoidal chloroplasts. — After Dodel-Port. 7S A TEXT-BOOK OF BOTANY. alga-like body consisting of branching septate filaments, which is known as the protonema, or prothallus (Fig. 44). The Proto- nema lies close to the surface of the ground and is more or less inconspicuous except for the green color. From the lower por- tion thread-like processes, or rhizoids consisting of a row of cells, are developed, which penetrate the ground. Sooner or later lateral buds arise from some of the lower cells. Growth continues from an apical cell which divides and gives rise to cells that differentiate into stem and leaves, forming an upright branch, which consti- tutes the structure commonly regarded as the '' moss plant " (Fig. 45, A). The leaf-bearing axis varies considerably in size; in some cases it is but a millimeter high, wdiereas in some species, as Polytrichum (Fig. 45), it may be several hundred millimeters in height. At the tip of the branch the antheridium (Fig. 49, A) and archegonium (Fig. 49, B) are fornied. These organs are developed in among the leaves and certain hairy processes, known as paraphyses ( Fig. 49, p). They may both occur at the end of one branch (Fig. 49, C) or they may occur on separate branches (Fig. 49, D), when the plants are said to be monoecious, whereas when these organs occur on separate plants (Fig. 49, A, B) the plants are called dioecious. In the case of dioecious plants the plant bearing the antheridium is frequently smaller and less com- plex than the one producing the archegonium. As already stated, the archegonium produces the egg-cell or female gamete {^gg) and the antheridium, the sperm cell or male gamete (sperm). The sperms in the Bryophytes are more or less filiform and are provided with a pair of cilia at one end. The antheridia, >owing to the peculiar mucilaginous character of the cells, only open when there is an abundance of moisture, when the sperms are discharged and move about in the water, some being carried to the archegonium, which likewise opens only in the presence of moisture. With the transferral of the sperms to the archegonium and the union of one of these with the ^gg which remains sta- tionary, the work of the gametophyte may be said to be com- pleted. The act of imion of the ^gg and sperm is known as FERTILIZATION, and when this is effected the next phase of the life history begins. The ^gg after fertilization divides and re-divides within the PRINCIPAL GROUPS OF PLANTS. 79 archegonlum, which becomes somewhat extended until finally it is ruptured. The dividing cells differentiate into a stalk and a spore case or sporangium which is borne at the summit, the whole structure being known as the sporogonium (Fig. 45). The base of the stalk is embedded in the apex of the moss plant, and is known as the foot, it being in the nature of a hausto- rium or nourishing organ. As the sporogonium develops and rises upward it carries with it the ruptured archegonium which forms a kind of covering over the top, called the calyptra (Fig. 45, ca). At first the sporangium is more or less uniform, but eventually differentiates into two kinds of tissues, the one being sterile and the other fertile (producing spores), which latter is known as the archesporium (Fig. 45, B, C), The fertile tissue in both the Liverworts and Mosses is variously disposed ; some- times it forms a single area and is dome shaped, spherical, or in the form of a half sphere. In other cases it is separated into two areas by sterile tissue. The sterile tissue which extends up into the dome-shaped archesporium, or which in other cases separates the fertile tissue into two parts, is known as the columella (Fig. 45, B, C). The sporangium in the mosses is capsule-like and the spores are distributed in three ways: (i) In some cases the capsule does not open, but when it decays the spores are liberated. (2) In other cases the capsule dehisces longitudinally in dry weather, and thus the spores are freed. (3) There is a third method in which the capsule is provided with a lid or operculum which comes off and permits the spores to escape, this being the most common method for the escape of the spores (Fig. 45, D). In the latter instance the mouth of the capsule is usually marked by one or two series of cells, constituting the peristome, which are teeth-like and characteristic for some of the groups of mosses. These teeth bend inward or outward, according to the degree of moisture, and assist in regu- lating the dispersal of the spores. In the sphagnum mosses there is no peristome, but, owing to unequal tension of the lid and capsule on drying, the lid is thrown off, and the spores are sometimes discharged with considerable force and sent to quite a distance (as much as 10 centimeters), in this way insuring their dispersal. The spores (Fig. 45, E) vary in diameter from 10 to 20 8o A TEXT-BOOK OF BOTANY. microns, being sometimes larger. They occur in groups of four in a mother-cell, and the spore-group is known as a tetrad, which is characteristic for the Bryophytes and the higher groups of plants. The spores therefore vary in shape from spherical tetra- hedrons to more or less spherical bodies, depending upon the degree of separation. The contents are rich in protoplasm and oil (Fig. 45, F). The wall consists of two layers, -the outer of which is either yellowish or brown and is usually finely sculptured. At the time of germination the outer wall is thrown off, and the protonema develops (Fig. 45, G). The spores may germinate almost immediately, or only after a considerable period. These spores are asexual and each one is capable of giving rise to a new plant. With the formation and dispersal of the spores the work of this generation terminates, and this phase is called the sporophyte or asexual generation, from the fact that it produces spores. Having thus followed the stages of development in the life history of a moss, we see that it is composed of the following parts: (i) The alga-like protonema; (2) the leafy branch which gives rise to an oospore (sexual spore), and (3) the sporogonium which produces asexual spores. The leafy branch is sometimes spoken of as the gametophore (gamete-bearer), and it and the protonema together constitute the gametophyte or sexual gen- eration, while the sporogonium represents the sporophyte or asexual generation. The protonema sooner or later dies off in most plants, but in other cases it persists, forming a conspicuous portion of the gametophyte. HEPATIC^. General Structure. — The Hepaticse or Liverworts (Fig. 46) are usually found in moist situations. The protonema formed on germination of a spore is filiform, and the plant body which develops from it consists of a flat, dichotomously-branching thallus, or it may in some of the higher forms differentiate into a leafy branch, as in the leafy liverworts. The thallus, owing to its position, has an upper and an under surface which are some- what diff'erent, as in Marchantia (Fig. 46), hence it is said to be PRINCIPAL GROUPS OF PLANTS. 8i DORSiVENTRAL. Froiii the lower colorless surface unicellular rhizoids arise (Fig. 47, h). The upper surface consists of several layers of cells containing chlorophyll which give the green color to the plant. Vegetative propagation may ensue by the lower portion of a branch dying and the upper portion continuing as an inde- pendent plant. Or special shoots, known as gemm.^i, may arise Fig. 46. Dichotomously branching thallus of the common liverwort {Marchantia polymorpha) showing near some of the margins the cup-like depressions in which gemmae are borne (c), and several archegoniophores (a). either on the margin of the thallus or in peculiar cupules, which, when detached by rain or other means, are capable of growing and producing a new plant. In addition the thallus body produces both antheridia and arch- egonia (Fig. 46) which may arise on special stalks above the sur- face. After fertilization of the egg-cell, which completes the work of the sexual generation of gametophyte, the sporophyte develops, 6 82 A TEXT-BOOK OF BOTANY. producing a sporogonium consisting of a short stalk which is embedded in the tissues of the gametophyte, and a capsule (spor- angium). The latter at maturity dehisces or splits and sets free the spores, which are assisted in their ejection by spirally banded cells called " elaters " (Fig. 48, C-F). The spores on germination give rise to a protonema which then develops a thallus bearing the sexual organs. As in the mosses, the sporogonium represents the asexual generation known as the sporophyte. Liverwort Groups. — There are three important groups of Fig. 47. Transverse section through the thallus of Marchantia Polymorpha. A, middle portion with scales (b) and rhizoids (h) on the under side; B, margin of the thallus more highly magnified, showing colorless reticulately thickened parenchyma (p), epidermis of the upper side (o). cells containing chlorophyll (chl), air pore (sp), lower epidermis (u). — After Goebel. Liverworts: (i) The Marchantia Group (Fig. 46), in which the thallus is differentiated into several layers and so somewhat thickened. Another character is the diversity in form of the sexual organs, which range from those which are quite simple to those which are highly differentiated. In Riccia the sexual organs are embedded on the dorsal (upper) side of the thalluc, while in Marchantia they are borne upon special shoots, one, which has a disk at the apex that bears the antheridia, known as the antheridio- phore, and another whose summit consists of a number of radiate PRINCIPAL GROUPS OF PLANTS. 83 divisions and bears the archegonia (Fig. 46) on the lower sur- face, known as the archegoniophore ; these being borne on separate plants. In Riccia, the simplest of the Liverworts, the sporangium is enclosed by the thallus and the spores are not liberated until the decay of the plant. (2) The JuNGERMANiA Group, known as "Leafy Liver- worts " or " scale mosses," includes those forms which are more Fig. 48. Anthoceros gracilis, one of the liverworts. A, thallus with 4 sporogonia; B, a ripe elongated sporogonium, dehiscing longitudinally and showing two valves between which is the slender columella; C, D, E, F, various forms of elaters; G, spores. — After Schilfner. or less moss-like and develop stems and small leaves. The sporo- gonium has a long stalk and the capsule is 4-valved, i.e., separates into four longitudinal sections at maturity. (3) In the Anthoceros Group (Fig. 48) the gametophyte is thallus-like and very simple in structure, the sexual organs being embedded in the thallus. The sporogonium is characterized by a bulbous foot and an elongated, 2-valved capsule. Like the thallus, 84 A TEXT-BOOK OF BOTANY. it develops chlorophyll and possesses stomata resembling those found in certain groups of mosses and higher plants. MUSCI. In the Mosses the archegonia always form the end of the axis of a shoot, whether this be a main one or a lateral one. As has already been stated (p. 78), the sexual organs are surrounded by leaves or leaf-like structures, known as perich?etia or peri- chaetal leaves, and by hair-like structures or paraphyses, both of which are considered to act as protective organs. Sometimes the groups of sexual organs together with the protective organs are spoken of as the " moss flower." As already stated, the Mosses are both monoecious (Fig. 49, C, D) and dioecious ( T^ig. 49, A, B), hence a moss flower may contain only one of the sexual organs or it may contain both. Mosses are also characterized by an abundant vegetative propagation. New branches are developed from the old. '" Almost every living cell of a moss can grow out into protonema, and many produce gemma: of the most difterent kinds." Entire shoots provided with reserve material are cut off and form new plants. In this way moss carpets are frequently formed in the woods, or masses in bogs. Moss Groups. — There are two general classes of mosses : ( i ) Sphagnum forms are those which produce leaves without nerves, and in which the sporogonium does not possess a long stalk or seta. What appears to be the stalk is the prolongation bf the gametophyte stem which is known as the pseudodium or " false stalk." These forms are characteristic of wet places. Some of the group, as Sphagnum proper, form " sphagnum bogs.'' New plants develop on top of the old, which latter gradually die and finally pass into sphagnum peat, which forms thick masses and finds use as a fuel. (2) The True Mosses are especially distin- guished by the differentiated character of the sporogonium, which not only produces a stalk but also the peristome (Fig. 45, p) , which when present is of great importance in distinguishing the different species. Economic Uses of Bryophytes. — The investigations on the chemistry of the Liverworts and Mosses have not been very numerous. The constituents which have been found are in the PRINCIPAL GROUPS OF PLANTS. 85 nature of tannin, resins, ethereal oils, glucosides, alkaloids, color- ing compounds, and organic acids like citric, oxalic, tartaric, and aconitic. In the mosses starch and silicon salts are found in addition. Sevei^al species of Marchantia and Jungermannia are Fig. 49. Longitudinal sections through tips of leafy branches of mosses. A. show- ing antheridia (a, b) in different stages of development and paraphyses or cell-threads Cc), the apical cell of which is spherical and contains chlorophyll, and leaves (d, e); B, show- ing archegonia (a) and leaves (b) ; C, section of Bryum showing both archegonia, and an- theridia, paraphyses, and leaves; D, section of Phascu-m showing archegonia (ar), antheridia (an), thread-like paraphyses (p), and leaves (b).— A. and B, after Sachs; C, after LLmpricht; D, after Hofmeister. used in medicine. Of the mosses the following have been found to have medicinal properties: Sphagnum ciispidatum, Oruiuiiia pulvinata; Fmiaria hygromctrica, Fontinalis autipyretica, and sev- eral species of Polytrichuin and Hypnum. 86 A TEXT-BOOK OF BOTANY. PTERIDOPHYTES. The Pteridophytes were formerly known as the Vascular Cryptogams. Like the Bryophytes, these plants show a distinct alternation of generations ; i.e.^ the gametophyte or sexual genera- tion alternates with the sporophyte or asexual generation. Their relation is, however, somewhat changed. In the Bryophytes the gametophyte is the most conspicuous and is looked upon as con- stituting the plant proper, whereas in the Pteridophytes the gametophyte is rather insignificant in size, while the sporophyte constitutes the generation or phase which is ordinarily regarded as the plant. In the higher members of the Pteridophytes the sporophyte is entirely detached from the gametophyte and is able to lead an independent existence. This group also shows a dis- tinct advance in structure. There is a differentiation into root, stem, and leaves, and the development of a system of conducting tissue known as the vascular system. The Pteridophytes include three principal groups, namely, ( I ) Filicales or Ferns, (2) Equisetales or Scouring Rushes, and (3) Lycopodiales or Club Mosses, which differ considerably in general appearance and general morphological characters. With the exception of the sperms in the Club ^Mosses, which are biciliate and somewhat resemble those in the Bryophytes, the sperms in the Pteridophytes are spirally coiled and multiciliate, and according to the number of cilia of the sperms some writers divide the Pteridophytes into two classes, namely, biciliate and pluriciliate (Figs. 51, C; 62, F). Some of the Pteridophytes, as Selaginella (Fig. 60), are dis- tinguished by the fact that they produce two kinds of asexual spores, which are known respectively as microspores (Fig. 60, F) and megaspores (Fig. 60, £). The two kinds of spores are formed in separate sporangia, which organs may occur on the same plant or on different plants. The sporangia have the cor- responding names, microsporangia (Fig. 60, B, i) and megaspor- angia (Fig. 60, B, g). This differentiation in sporangia and spores also leads to a differentiation in the resulting gametophytes, the microspores giving rise to gametophytes which produce antheridia, and hence called male gametophytes ; and the megaspores to PRINCIPAL GROUPS OF PLAXTS. 87 gametophytes which give rise to archegonia, and hence called female gametophytes. When a plant produces both microspores and megaspores it is said to be heterosporous, as in Selaginella (Figs. 60, 62, and 63) ; while one that produces but one kind of sporangium and one kind of asexual spores is said to be isosporous. In this connection attention should be called to the fact that the spores from a single sporangium of an isosporous plant may give rise to male and female gametophytes, which shows that a certain degree of differentiation in the spores has already taken place. The causes leading to the differentiation of the spores seem to be Fic. 50. Male fern [Dryopteris {Aspidium or Nephrodium) Filix-mas]. A, prothallus of gametophyte as seen from the under (ventral) side showing archegonia (ar), antheridia (an), and rhizoids (rh) ; B, prothallus showing young plant (sporophyte) which has devel- oped from an oospore and is still connected with the gametophyte, roots (w), and the first leaf (b). — After Schenck. connected with nutrition, those nuclei which are in more favorable positions giving rise to larger and better nourished spores which eventually lead to the formation of the megaspores, and those which are less favorably placed leading to the microspores. The subject of heterospory is one of great interest, and when it is pointed out that all of the higher plants are heterosporous the subject has even more interest. FILICALES. • General Characters. — On germination the asexual spore in the Filicales or Ferns gives rise to a thallus-like body known as B^ A TEXT-BOOK OF BOTANY. the prothallus which is frequently dorsiventral and in a number of cases somewhat heart-shaped, but varies considerably in out- line, being sometimes more or less tuberous. The prothallus is frequently but a few millimeters in diameter, and the cells usually contain chloroplasts. On the under or ventral surface rhizoids are usually present (Fig. 50, rh). The sexual organs usually arise on the lower surface (Fig. 50), but they may develop on the upper or dorsal surface or even laterally. A single prothallus gives rise to both kinds of organs, unless stunted in its growth, when it produces antheridia only. Fig. 51. A, B, development of archegonia of a fern (Pteris) showing the neck (h), the neck-canal cells (k), and ousphere (e). — After Strasburger. C, development of antheridium in the Venus-hair fern {Adianlum Capillus-Veneris): prothallus (p), antheridium (a), sperm (s), sperm mother cell with starch grains (b); I, immature state of antheridium, II, sperms developed, and III, discharge of sperm mother cells and escape of coiled and pluriciliate sperms. — After Sachs. The antheridia either develop upon or are sunk in the tissues of the prothallus. The archegonia (Fig. 51) are not flask-shaped as in the Bryophytes. The venter containing the oosphere or egg- cell (Fig. 51, e) is embedded in the thallus, the structure being surmounted by a few-celled neck (Fig. 51, h) . The inner cells of the neck are known as canal cells (Fig. 51, k) , and these at the time of ripening of the tgg swell and exit through the opening of the archegonium, through which then the sperms enter, one of which unites with the tgg, thus effecting fertilization. The fer- tilized Qgg or oospore takes on a cellulose membrane. PRINCIPAL GROUPS OF PLAXTS. 89 The oospore which is held in the venter of the archegonium is not a resting spore, but germinates immediately and early differen- tiates into the several organs ( Fig. 52 ) . These arise independently and include a stem-bud (Fig. 52, s) ; a first leaf or cotyledon (Fig. 52, b), so called because it does not arise out of the stem as the later leaves do; a first or primary root (Fig. 52, w) ; and a foot or haustorial organ (Fig. 52, /) whereby it obtains nutri- ment from the prothallus (Fig. 52, pr). This latter organ is, how- ever, only a temporary provision, for as soon as the root grows out and penetrates the soil, it dies off and the sporophyte thus becomes independent. The stems are frequently more or less con- FiG. 52. The brake fern (,Pteris). A, differentiation of cells in germinating oospores; B, later stage showing development of embryo: pr, prothallus; f, foot embedded in the archegonium (aw); w, root; s, young stem; b, young leaf. — A, after Kienitz Gerloff; B, after Hofmeister. densed and lie prostrate in the soil, developing roots from the under surface and leaves from the sides and upper surfaces. The leaves which constitute the conspicuous part of the ordinary ferns consist of a stalk and lamina or blade on which are borne the spor- angia (Figs. 53 to 55). The sporangia usually occur on the under surface of the leaf in groups or clusters known as sori (Fig. 53, A). The sori are of characteristic shape and in certain species are covered by a plate called the indlsium (Fig. 53, B) which rises from the epidermis. In some species the entire leaf becomes a spore-bearing organ, and is then known as a sporo- PHYLL (Figs. 54, 55), to distinguish it from the foliage leaves. The sporangia develop a row of cells around the margin consti- 90 A TEXT-BOOK OF BOTAXV. tuting what is known as the annulus (Fig. 53, 11). The form of the annulus determines the manner of dehiscence of the sporangia, which occurs on drying. The spores are ejected with consider- FlG. S3. Male fern [Dryopteris (Aspidium or Nephrodiiim) Filix-mas]. A, portion of leaflet showing a number of more or less reniform sori near the mid-vein; B. transverse section through a ripe sorus showini? clusters of stalked spnransria, which are covered by the indusium (i), an outgrowth of the leaflet; C, a closed but ripe sporangium showing the annulus or ring (n), and the irregular-shaped spores within; D, showing the manner of opening of the mature sporangium and the dispersal of the spores; E, two spores much magnified. — After Dodel-Port. able force (Fig. 53, D). They (Fig. 53, E: Fig. 57) are either bilateral or tetrahedral and require a short period to elapse before they germinate. They retain their vitality for a long time, except those which are green, i.e., contain chlorophyll. The spores are PRINCIPAL GROUPS OF PLANTS. 91 greenish or yellowish in color, variously sculptured, and vary from 0.025 mm. to 0.158 mm. in diameter. Fern Groups. — There are a number of distinct groups of Tig. 54. Several Osmundas. i, the royal fern (O. regalis) showing fertile tip of branch and sterile bipinnate leaflets below; 2, Clayton's fern (0. Clayto)iiaua) showing three pairs of fertile leaflets in the middle and a number of sterile leaflets above and below; 3, cinnamon fern (O. cinnamomea) showing a fertile leaf (sporophyll) to the left arid a sterile leaf (foliage leaf) to the right. ferns which vary considerably in appearance, (i) In the Tropics as well as in greenhouses tree ferns, characterized by an over- ground stem, occur. The leaves arise at the summit of the stem or trunk and form a crown. 92 A TEXT-BOOK OF BOTANY. (2) The True Ferxs include by far the lar^e.t nn,^K , species which inhabit temperate rejons. VZ^ZnZel ably m s.ze. ranging from quite diminutive plants =; tn , , "^':- a3 the slender Cliff Brake iPeU^a «...,4:::ilV,;n,';!f; with two leaves of the cotnmon Synodv (pZ.^* '^ ,'"" W«.v,™™«); 3. rhizome wort iAspU„iu„. ies of Holland. The word mutation means a change. In this sense it means a sudden change and has to do with the fact that among the oft'spring of a certain individual may be found one or more individuals markedly differing from the parent, so much so as to be regarded in a few instances as a distinct species. Moreover, these mutants, as they are called, continue to breed true, thereby giving rise to what might very well be called a new species. In the study of mutation many experiments have been conducted by scientists and breeders. Mendel's Law. — In intimate relationship with the subject of evolution is the question of heredity. In the middle of the last century there lived an Austrian monk, Mendel by name, who ex- perimented with the cultivation of peas and other plants in the monastery garden. In his studies he discovered a certain law underlying the transmission of characters in reproduction. This law, which for many years lay hidden from the scientific world, was recently brought to light and now forms the basis of most of the recent breeding experiments and is of profound value in the study of heredity. In the simplest case it is as follows: If two different species, A and B, are crossed, the result is a hybrid (AB) which combines certain characters of both parents. When this hybrid propagates, the progeny splits up into three sets : one resembling the hybrid parent (AB) ; and the other two sets re- sembling the parent forms (A and B) that entered into the hybrid. Mendel's law is a statement of the mathematical ratio expressed by these three groups of forms derived from a " splitting" hybrid. This means that in a series of generations initiated by a hybrid, ap- proximately one-half of the individuals of each generation will represent the hybrid mixture, one-fourth of the individuals will represent one of the pure forms that entered into the hybrid, and the remaining fourth will represent the other pure form. Of course, the 1:2:1 ratio holds only when the one unit-character is involved, and does not apply to the hybrids as a whole, as differ- ent characteristics are generally inherited independently of others. 1 PRINCIPAL GROUPS OF PLANTS. 133 It should be understood that the use of hybrids in such experi- mental work is simply a device to secure easy recognition of the contributions of each parent to the progeny. For example, if red and yellow races of corn are crossed, it is very simple to recognize the color contribution of each parent to the hybrid progeny, when it would be impossible to separate the contribution of two yellow parents. The inference is, that what is true of hybrids is true of forms produced in the ordinary way, so that laws of heredity obtained from a study of hybrids may be regarded as laws of heredity in general. In the working out of Mendel's law it has been observed that, while one- fourth of the progeny are like one parent, the remaining three-fourths will all show the characteristics of the other parent, although only one of the remaining three-fourths will breed true. That is to say that the hybrids, which make up half of the progeny, look like one of the parents, but all do not breed true to that parent. In this case the character of the true pure-strain parent which marks the hybrids is said to be a dominant character, while the character of the other pure-strain parent is said to be a recessive character, because in the hybrids its presence can not be observed and can be discovered only by breeding the hybrids. It is only by experiment and breeding that dominant and recessive characters can be determined. For instance, in the culture of peas the character of being tall has been found to be dominant over the character of being dwarf. This means that all the hybrids will be tall, although one-fourth of their progeny will be dwarf. Again in the pea, the character of having a round seed is found to be dominant over that of having a wrinkled seed. In wheat the character of being beardless is dominant over that of being bearded, and again the character of being susceptible to rust is dominant over that of being immune to rust. The infinite number of characters which complicates the study of hybrids and the fact that in breeding it is sometime? the dom- inant and sometimes the recessive character which is the desirable one to maintain suggest at a glance the breadth and difficulty of the problem. CHAPTER II. CELL-CONTENTS AND FORMS OF CELLS. A TYPICAL living cell may be said to consist of a wall and a protoplast (a unit of protoplasm), although it is often customary to refer to the protoplast alone as constituting the cell. This is in view of the fact that the protoplasm which makes up the sub- stance of the protoplast is the living substance of the plant. Besides the protoplasm other substances are also found in the cell, hence in a general w^ay the cell may be said to be composed of a wall and contents (cell-contents). The wall, as well as the cell-contents, consists of a number of substances, and, as the cell- contents are of primary importance in the development of the plant, their nature and composition will be considered first. Cell-contents. — With the distinction already made the cell- contents may be grouped into two classes: (i) Protoplasmic, or those in which the life-processes of the plant, or cell, are mani- fested ; and (2) non-protoplasmic, or those which are the direct or indirect products of the protoplast. The first class includes the protoplasm with its various dififerentiated parts, and the second, the various carbohydrates (starches and sugars), calcium oxalate, aleurone, tannin, oil, and a number of other substances. PROTOPLASMIC CELL-CONTENTS. Protoplasm. — Protoplasm occurs as a more or less semi- fluid, slimy, granular, or foam-like substance, which lies close to the walls of the cell as a relatively thin layer and surrounding a large central cavity or vacuole filled with cell-sap, or it may be distributed in the form of threads or bands forming a kind of net- work enclosing smaller vacuoles. Protoplasm consists of two comparatively well differentiated portions: (i) Certain more or less distinct bodies which appear to have particular functions and to which a great deal of study has been given, as the nucleus and plastids; and (2) a less dense portion which may be looked upon 134 CELL-CONTENTS AND FORAIS OF CELLS. 135 as the ground substance of the protoplast and which is now com- monly referred to as the cytoplasm (see Frontispiece). These differentiated bodies and the cytoplasm are intimately associated and interdependent. The nucleus and cytoplasm are present in all living cells, and it is through their special activities that cell Fig. 85. Successive stages in nuclear and cell division, n, nucleolus; c, centrospheres s, chromosomes; sp, spindle fibers; A, B, C, division of chromosomes, i, cell with nucleus containing nucleolus (n), and two centrospheres (c); 2, showing separation of nucleus into distinct chromosomes (s) and the centrospheres at either pole of the nucleus; 3. forma- tion of spindle fibers (sp) ; 4, longitudinal division of chromosomes; 5, division of the cen- trospheres; 6, 7, 8, further stages in the development of the daughter nuclei; 9, formation of cell-wall which is completed in 10 giving rise to two new cells. — After Strasburger. division takes place. When, in addition, plastids are present, con- structive metabolism takes place, whereby complex substances are formed from simpler ones. Besides the nucleus and plastids other protoplasmic structures are sometimes found embedded in the cytoplasm. These are the CENTROSPHERES (Fig. 85, c) , Small spherical bodies that are 136 A TEXT-BOOK OF BOTANY. associated with the nucleus and appear to be concerned in cell division. There are, in fact, quite a number of minute bodies in the cytoplasm which may be always present or only under certain conditions, and which are grouped under the general name of MICROSOMES or MICRQSOMATA. Chemically protoplasm is an extremely complex substance, but does not appear to have a definite molecular structure of its own, being composed in large measure of proteins, a class of organic compounds which always contain nitrogen, and frequently phos- phorus and sulphur. The molecule of the proteins is large and more or less unstable, and hence subject to rapid changes and a variety of combinations, and it is to these interactions that the vital activities of the plant are attributed. Nucleus. — The nucleus consists of (i) a ground substance in which is embedded (2) a network composed of threads con- taining a granular material known as chromatin, and (3) gen- erally one or more spherical bodies called nucleoles, the whole being enclosed by (4) a delicate membrane (Fig. 85). The chro- matin threads are readily stained by some of the aniline dyes, and are mainly composed of nucleins (proteins) rich in phosphorus, which by some writers are supposed to be essential constituents of the nucleus and necessary to the life of the protoplast. Chroma- tin is constant in the nucleus, and prior to cell division the threads become organized into bodies of a definite number and shape known as chromosomes (Fig. 85, s). Plastids. — The plastids or chromatophores form a group of differentiated protoplasmic bodies found in the cytoplasm (Front- ispiece) and are associated with it in the building up of complex organic compounds, as starch, oil, and proteins. The term chro- matophore means color-bearer, but applies also to those plastids which may be colorless at one stage and pigmented at another. Hence we may speak of colorless chromatophores. According to the position of the cells in which these bodies occur and the functions they perform, they vary in color — three distinct kinds being recognized, (i) In the egg-cell and in the cells of roots, rhizomes, and seeds the plastids are colorless and are called leuco- PLASTiDS. (2) When they occur in cells which are more or less exposed to light and produce the green pigment called chloro- CELL-CONTENTS AND FORMS OF CELLS. 137 phyll, they are known as chloroplastids or chloroplasts. ( 3 ) In other cases, independently of the position of the cells as to light or darkness, the plastids develop a yellowish or orange-colored principle, which may be termed chromophyll, and are known as CHROMOPLASTiDS. Chloroplastids are found in all plants except Fungi and non-chlorophyllous flowering plants, and chromoplas- tids in all plants except Fungi. Plastids vary in form from more or less spherical to polygonal or irregular-shaped bodies, and they increase in number by simple fission. They suffer decom- position much more readily than the nucleus, and are found in dried material in a more or less altered condition. Leucoplastids. — The chief function of the leucoplastids is that of building up reserve starches or those stored by the plant for food, and they may be best studied in the common potato tuber, rhizome of iris, and the overground tubers of PJiaiiis (Fig. 2, b). The reserve starches are formed by the leucoplastids from sugar and other soluble carbohydrates. The chloroplastids occur in all the green parts of plants (see Frontispiece). They vary from 3 to 1 1 /x in diameter and are more or less spherical or lenticular in shape, except in the Algae, where they are large and in the shape of bands or disks (Figs. 8 and 9) , and generally spoken of as chromatophores. Chlo- roplastids are found in greater abundance in the cells near the upper surface of the leaf than upon the under surface, the pro- portion being about five to one. These grains, upon close exam- ination, are found to consist of (i) a colorless stroma, or liquid, in which are embedded (2) green granules; (3) colorless gran- ules; (4) protein masses; (5) starch grains; and (6) a mem- brane which surrounds the whole. The green granules are looked upon as the photosynthetic bodies ; the colorless grains are sup- posed to assist in the storing of starch or in the production of amylase, the conditions for these processes being directly opposite, i.e., when photosynthesis is active, starch is stored, and when this process is not going on, as at night, amylase is produced and the starch is dissolved. The protein grains may be in the nature of a reserve material of the plastid and probably are also formed in connection with photosynthetic products. While the protoplasm has been termed by Huxley *' The phys- 138 A TEXT-BOOK OF BOTANY. ical basis of life," the chloroplastid has been spoken of as the mill which supplies the world with its food, for it is by the process of photosynthesis that the energy of the sun is converted into vital energy, and starch and other products formed, which become not only the source of food for the plant itself, but also the source of the food-supply of the animals which feed upon plants. In other words, horse-power is derived from the energy of the sun which is stored in the starch grains of the chloroplastids. Chromoplastids. — In many cases, as in roots, like those of carrot, or flowers and fruits, which are yellowish or orange- colored, there is present a corresponding yellow pigment, and to this class of pigments the name chromophyll may be applied. Some of these pigments, as the carotin in carrot, have been iso- lated in a crystalline condition (see Frontispiece, also Fig. 86). Chromoplastids usually contain, as first pointed out by Schim- per and Meyer, protein substances in the form of crystal-like bodies ; starch-grains may also be present. The chromoplastids are very variable in shape and in other ways are markedly differ- ent from the chloroplastids. They are more unstable than the chloroplastids, and are formed in underground parts of the plant, as in roots, as well as in parts exposed to the light, as in the flower. Their formation frequently follows that of the chloroplastids, as in the ripening of certain yellow fruits, such as apples, oranges, persimmons, etc. The PLASTID PIGMENTS are distinguished from all other color- substances in the plant by the fact that they are insoluble in water and soluble in ether, chloroform, and similar solvents. In fact, they are but little affected by the usual chemical reagents under ordinary conditions. Apart from the difference in color, the yellow pigment (chro- mophyll) is distinguished from the green (chlorophyll) by the fact that the latter is said to contain nitrogen, and also by their difference in behavior when examined spectroscopically, chloro- phyll giving several distinct bands in the yellow and orange por- tion of the spectrum, which are wanting in the spectrum of the yellow principle. Cytology, or the science of cell formation and cell life. Dur- ing recent years considerable attention has been given by botanists I CELL-CONTENTS AND FORMS OF CELLS. i 39 Fig. 86. *u f ■ ( u i"°"^ ^"""^^ °^ Chromoplastids: A. from the fruit of Bryonia dioica; B. tne truit of the European mountain ash {Pyrus aucuparia); C. the petals of nasturtium Uropa^olum majus); D petals of- Iris Pseudacorus; E, petals of Tulipa Gcsvcriana- {Dauciis Caro/a).— After Dippel in "Das Mikroskop." F, the rout of carrot I40 " A TEXT-BOOK OF BOTANY. to the studies of the protoplasmic structures of the cell, especially the nucleus ; the reason for this being that all of the vital phe- nomena of which living organisms are capable have their origin in these substances. The nucleus is regarded as a controlling center of cell activity, for upon it all growth and development of the cell depend, and it is the agent for the transmission of specific qualities from one generation to another. Furthermore, cytolo- gists look upon the chromatin material of the nucleus as being the agent for the transmission of individual characters to offspring. The reason for this is that in the male generative cell it is prac- tically only the nucleus which fuses with the egg-cell, no other substances entering into the union. The centrosomes are usually apparent during the process of nuclear division and by some are regarded as the controlling organ of cell division, hence they are known as the dynamic centers of the cell. The functions of the plastids and cytoplasms are largely, if not entirely, connected with the synthesis, transportation, and dissociation of metabolic substances. NON-PROTOPLASMIC CELL-CONTENTS. The non-protoplasmic constituents of plants may be said to differ from the protoplasmic cell-contents in two important partic- ulars, namely, structure and function. For convenience in con- sidering them here, they may be grouped as follows: (i) Those of definite form including (a) those which are colloidal or crystalloidal, as starch and inulin ; (b) those which are crystalline, as the sugars, alkaloids, glucosides, calcium oxa- late ; (c) composite bodies, as aleurone grains, which are made up of a number of different substances. (2) Those of more or less indefinite form, including tannin, gums and mucilages, fixed and volatile oils, resins, gum-resins, oleo-resins, balsams, caoutchouc, and also silica and calcium car- bonate. I. SUBSTANCES DEFINITE IN FORM. COLLOIDAL OR CRYSTALLOIDAL. Starch is the first visible product of photosynthesis, although it is probable that simpler intermediate products are first formed. This substance is formed in the chloroplastid (see Frontispiece) and is known as assimilation starch. Starch grains are CELL-CONTENTS AND FORMS OF CELLS. 141 Fig. 87. Successive stages in the development of starch grains, in Fellionia Daveauana (A to N); and in the fruits of the potato plant. Solatium tuberosum (P to R). In A. two plastids with a number of small starch grains; B, a plastid in which a single starch grain is differentiated; C to L, successive stages of the development of a single grain, the plastid body being shown on the surface (p) ; M, N, the development of several 2-compound starch grains; P to R, the development of additional layers at right angles to the original grain. — After Dippel in "Das Mikroskop." usually found in the interior of the chloroplastid, but may attain such a size that they burst through the boundary wall of the plastid, which latter in the final stage of the growth of the starch grain forms a crescent-shaped disk attached to one end of the 142 A TEXT-BOOK OF BOTANY. grain, as in Pellionia. Starch is changed into soluble carbohy- drates by the aid of ferments and probably other substances, and in this form is transported to those portions of the plant requiring food. The starch in the medullary rays and in other cells of the A „ D 13 "=> fisEl l-.XV Fig. 88. A, potato starch grains showing the excentral and circular point of origin of growth, and lamellae; B, maranta starch grains showing fissured point of origin of growth, and distinct lamellae; C, wheat starch grains showing indistinct point of origin of growth, and lamellae; D, com starch grains, which are more or less polygonal in outline and have a 3- to 5-angled point of origin of growth. wood and bark of plants is distinguished by being in the form of rather small and nearly spherical grains. In rhizomes, tubers, bulbs, and seeds the grains are, as a rule, quite large, and possess CELL-CONTENTS AND FORMS OF CELLS. 143 more or less distinct characteristics for the plant in which they are found. Starch of this kind is usually spoken of as ke-servl: STARCH (Fig. 87). Occurrence of Starch. — ^Starch is found in most of the algae and many of the mosses, as well as in the ferns and higher plants. The amount of starch present in the tissues of plants varies. In the grains of rice as much as 84.41 per cent, has heen found. This constituent also varies in amount according to the season of the year. Rosenberg has observed that in certain perennial plants there is an increase in the amount of starch during the winter months, whereas in other plants it decreases or may entirely disappear during this period. In the latter case, from six weeks ^r\O0- Fig. 89. A, starch grains of Iris florentirta showing peculiar horseshoe-like fissure extending from point of origin of growth; B, irregular starch grains of calumba root; C, peculiar beaked starch grains of ginger rhizome; D, starch grains of bean showing irregular longitudinal lissures; E, compound starch grains of oat. to two months in the spring are required for its re-formation, and about an equal period is consumed in the fall in effecting its solution. Structure and Composition of Starch Grains. — The formula which is generally accepted for starch is (CcHioOj;),j, this being recognized by Pfeffer, Tollens, and Mylius. It is supposed that the molecule of starch is quite complex, it being composed of dif- ferent single groups of CeH^oO^ or multiples of the same. While this formula may be accepted in a general way, still it has been shown that there are at least two substances which enter into the composition of the starch grain, and more recent studies tend to show that it is in the nature of a sphero-crystalloid, resembling inulin in some respects. Starch grains have an interesting struc- 144 A TEXT-BOOK OF BOTANY. ture. They vary in shape from ovoid or spherical to polygonal, and have a more or less distinct marking known as the " hilum," '' nucleus," or the point of origin of growth. The substances of which the grains are composed are arranged in concentric layers or lamellae which are more or less characteristic and which sometimes become more distinct on the application of certain reagents (Fig. 90). The point of origin of growth and alternate lamellae are stained by the use of gentian violet and other aniline dyes, which may be taken to indicate that these layers contain a colloidal substance somewhat resembling a mucilage, while the Fig. 90. Successive stages in the swelling and disintegration of starch grains in the presence of water on the application of heat (6o°-7o° C.j.or certain chemicals. Potato starch i-io; wheat starch 11-22. alternating layers are stained with dilute iodine solutions and are probably composed of soluble starch, this latter corresponding to the a-amylose of Arthur Meyer or the granulose described by Nageli. The peripheral layer of the grain appears to be a distinct membrane. It is quite elastic, more or less porous, and takes up stains readily. While starch grains usually occur singly, they are not infre- quently found in groups of two, three, or four grains, when they are spoken of as two-, three-, or four-compound. In some of the CELL-CONTENTS AND FORMS OF CELLS. 145 cereals, as rice and oat, they are lOo-compound or more. The individuals in compound grains are in some cases easily separated from one another. This occurs frequently in microscopical prep- arations, and is especially noticeable in the commercial starches. The various commercial starches belong to the class of reserve starches and may be distinguished by the following characteristics : ( 1 ) The shape of the grain, which may be spherical, ellipsoidal, ovoid, polygonal, or of some other characteristic form (Figs. 88 and 89). (2) The size of the grain, which varies from i to 2 /x to about 100 fi in diameter. (3) The position of the point of origin of growth, which may be central (Fig. 88, C, D) or excentral (Fig. S8, A, B). In some cases there are apparently two points of origin of growth in a single grain, and it is then spoken of as " half-compound," as occa- sionally found in potato. (4) The shape of the point of origin of growth, which may be spherical, as in potato (Fig. 88, A); cross-shaped, as in maranta (Fig. 88, 5) ; a three- or five-angled fissure or cleft, as in corn (Fig. 88, Z^), or indistinct or wanting, as in wheat (Fig. 88, C). (5) The convergence of the lamellae, which may be either toward the broad end of the grain, as in maranta (Fig. 88, B), or toward the narrow end, as in potato (Fig. 88, A). In most grains the lamellae are indistinct or wanting, as in wheat and corn (Fig. 88, CL'). (6) Behavior toward dilute iodine solutions, the color pro- duced varying from a deep blue in most starches to a red or yellowish-red, as in the amylodextrin grains of mace. (7) The temperature (45°-77° C.) at which the " kleister " or paste is formed, and its consistency. (8) The appearance as viewed by polarized light, the distinct- ness of the cross, as well as the degree of color produced, varying considerably as Nichol's prism is revolved (Fig. 91). (9) Behavior toward various reagents, as chromic acid, cal- cium nitrate, chlor-zinc-iodide, diastase, and various aniline stains, showing peculiarities of both structure and composition (Fig. 90). General Properties of Starch. — If starch is triturated with 146 A TEXT-BOOK OF BOTANY. water and the mixture filtered, the filtrate does not give a reaction with iodine solution ; if, on the other hand, the starch is previously triturated with sand and then with water, the filtrate becomes blue *J '4 :< *^ ^ ^ rii ;^: & ^ // H .'^^ Fig. 91. Larger grains of various starches as viewed through the micropolariscope when mounted in oil: A, potato (70-80 m) ; B, wheat (30-40 m); C, ginger (30-50 m); D, galangal (45-55 m); E, calumba (40-60 m); F, zedoary (50-75 1^); G. maranta (35-50 n); H, colchicum (10-20 fi); I, com (20-25 f*); J. cassava (20-35^ ); K, orris root (30-35 m). on the addition of iodine solution. It appears that in the latter operation the wall of the grain is broken and the soluble starch present in the grain is liberated. CELL-CONTENTS AND FORMS OF CELLS. 147 If dry starch and iodine are triturated together no color or, at the most, a faint blue color is produced; whereas, if a little water is added and the trituration repeated, a deep blue color is immediately produced. The blue color of starch solution and iodine disappears on the application of heat, but slowly returns on cooling the solution, but not with the same degree of intensity, part of the iodine being volatilized. When starch is heated with glycerin it dissolves, and if alco- hol is added to the solution, a granular precipitate is formed which is soluble in water, the solution giving a blue reaction with iodine. When starch is heated with an excess of water at 100° C. for even several weeks, dextrinization of the starch does not take place ; i.e., the solution still gives a blue color with iodine. I f , how- ever, a mineral acid be added, it is quickly dextrinized, turning violet-red, reddish, and yellowish with iodine ; finally, maltose and dextrose are produced, these giving no reaction with iodine, but reducing Fehling's solution. The ferments and other chemi- cals have a similar effect on starch. When dry starch is heated at about 50° C. from 15 to 30 min- utes the lamellae and crystalloidal structure become better defined and the polarizing effects produced by the grains also become more pronounced. When starch is mounted in a fixed oil, as almond, the polarizing effects are more pronounced than when it is mounted in water, but the inner structure is not usually apparent, unless the starch has been previously heated. (For literature on the starch grain see Kraemer, Bot. Gazette, \o\. XXXIV, Nov., 1902; Ibid., Vol. XL, Oct., 1905; also Eighth in- ternational Congress of Applied Chemistry, Vol. 17, p. 31.) Botanical Distribution of Starch. — This constituent is commonly present as a reserve material in a large number of plants. The sources of the commercial starches are constantly being extended. The commercial starches are chiefiy obtained from one or more genera of the Gramineye, Marantace?e, Eu- phorbiacese, and Solanaceae. The following is a list of the fami- lies yielding one or more economic products which contain starch : Cycadaceae, Gramineae, Araceae, Liliace?e, Amaryllida- ceae, Iridacese, Musaceae, Zingiberaceae, Cannaceae, Marantaceae, 148 A TEXT-BOOK OF BOTANY. Orchidacese, Piperacese, Fagacese, Aristolochiaceae, Polygonaceae, Phytolaccace^, Nymphseacese, Ranunculacese, Menispermaceae, Myristicacese, Lauraceae, Papaveraceae, Cruciferae, Rosaceae, Legu- minosae, Geraniaceae, Rutaceae, Simarubaceae, Euphorbiaceae, Celastrace^e, Sapindaceae, Rhamnaceae, Malvaceae, Thymelaeaceae, Punicaceas, Myrtaceae, Umbelli ferae, Loganiaceae, Apocynaceae, Convolvulaceae, Solanaceae, Scrophulariaceae, Gesneraceae, Rubia- ceae, Caprifoliaceae, Valerianaceae, and Cucurbitaceae. Percentage of Starch in Plants. — The amount of starch in economic plants, especially those used for food, is very high, being, on an average, much greater than that of any other con- stituent except water. The percentage of starch, calculated on dry material, in a number of foods and spices is here given : Bar- ley, 53.45 to 72.90; cardamom seed, 18.66 to 40.53; carrot, 0.87 to 0.92; chestnut, 37.31 to 47.93; chinquapin, 44.45; cinnamon, 10.44 to 65.72 ; cloves, 9.41 to 51.03 ; cocoa (cacao), 3.83 to 48.73 ; corn, 36.72 to 77.54; ginger, 46.16 to 62.53; lentils, 45.37; mace, 26.77 to 56.11 ; millet, 56.70 to 74.40; nutmeg, 17.19 to 40.12; oak acorns, 32.64; oats, 42.64 to 63.50; onion, 11.00 to 29.39; peas, 50.02 to 57.59; pepper, 28.15 to 64.92; pimenta, 16.56 to 59.28; potatoes (sweet), 8 to 78.59; potatoes (white), 25.00 to 75.00; rice, 74.80 to 84.41 ; rye, 51.15 to 74.08; wheat, 53.66 to 76.51. ]\L\NUFACTURE OF Starch. — In the preparation of commer- cial starches the object is to break the cells and separate the starch grains, freeing the product from the other constituents of the cell as much as possible. The preparation of potato starch is exceedingly simple, as all that is necessary is to reduce the tubers to a fine pulp, the starch grains being separated from the tissues by means of a sieve. The water containing the starch is removed to tanks, the separation of the starch being facilitated by the addition of alum or sulphuric acid which coagulates the dissolved protein substances. The starch is washed and dried over porous bricks by exposure to air. It is then thoroughly dried in a hot chamber, reduced to a powder, and sifted. One hundred pounds of potatoes yield about 15 pounds of dry starch. It is said that diseased tubers produce as good a quality of starch as the sound tubers. In the preparation of the cereal starches the gluten interferes I CELL-CONTENTS AND FORMS OF CELLS. 149 with their ready separation. The process is therefore moditied by either allowing the cereals to ferment, whereby the gluten is rendered soluble and easily removed, or the flour is made into a dough which is kneaded over running water, whereby the starch grains are separated. The starch is subsequently purified by washing and settling. It is dried by gentle heat and assumes the columnar structure as seen in the more or less irregular particles in the commercial product. One hundred pounds of wheat yield from 55 to 59 pounds of starch, the fermentation process giving a larger amount. In the preparation of corn starch, a weak solution of sodium hydrate is usually employed to facilitate the separation of the starch. Sulphurous acid is also used. One hundred pounds of corn yield 50 pounds of starch. Rice starch is prepared by either an alkaline process or by an acid process similar to that used in the manufacture of corn starch, hydrochloric acid being employed instead of sulphurous acid. Rice yields a greater percentage of starch than any of the other raw materials, 100 pounds of the grain giving 70 per cent, of starch. Starch is used as a food and for various other industrial pur- poses. The principal nutritive starches are sago, tapioca, and corn. Maranta, or arrowroot starch, is largely employed in the preparation of infant foods. Much of the dextrin of commerce is prepared by the action of dilute acids upon potato starch. Starch for laundry purposes is prepared from wheat. Rice starch is largely used as a dusting-powder. Cassava starch has consider- able advantages over the other starches in the making of nitro- compounds, and is employed in the preparation of smokeless powders. Pyrenoids. — In the chromatophores of a number of algae a distinct body is observed. It is more or less of a lenticular shape, stained a dark purple on the addition of iodine, and is known as a Pyrenoid. It is not definitely known wliether it is a true cell organ having a function similar to the plastids in manufacturing starch or whether it is merely a m.ass of complex reserve substances. It can be dififerentiated readily into two distinct portions: an inner, somewhat highly refracting and 150 A TEXT-BOOK OF BOTANY. consisting of protein matter, and an outer layer, consisting of a number of starch grains. The studies of Baubier tend to show that the pyrenoid is perfectly differentiated and independent of the chromatophore, and that the starch is formed from a leuco- plastid which surrounds a phyto-globulin or crystalloid at the center. This would quite agree with the studies of Timberlake, who observed the complete conversion of the pyrenoid into starch. That the substances of the pyrenoid are in the nature of reserve food materials, is apparent from the fact that the pyrenoid entirely disappears in Hydrodictyon prior to spore formation, and that it is afterward formed anew in the young cells, thus behaving very much like a leucoplastid. Attention should also be directed to the fact that in some of the unicellular and filamentous algse the pyrenoid divides during the division of the cell, thus behaving like other protoplasmic organs. Inulin appears to be an isomer of starch and occurs in solution in the cell-sap of parenchyma cells of stems and roots, being also found in the medullary rays. It exists in greatest amounts during the early fall and spring, being changed at other times to levulose. In the Monocotyledons it is found in the Amaryllidaceae, Liliacese, etc. In the Dicotyledons it is characteristic of the Compositae, but also occurs in the following: Asclepiadacese, Bignoniaceai, Cactaceae, Campanulace^e, Capri foliacese, Compositae, Cruci ferae, Droseraceae, Euphorbiace^, Geraniaceae, Labiatae, Leguminosae, Lythraceas, Magnoliaceae, jNIenispermaceae, Moraceae, Nepenth- aceae, Passifloraceae, Ranunculaceae, Rubiaceae, Rutaceae, Salicaceae, Santalaceae, Theaceae, Thymelaeaceae, Urticaceae, Valerianaceae, Verbenaceae, V^iolaceae, etc. According to Dragendorft, there are two forms of inulin ; one of which is amorphous and easily soluble in water, and another which is crystalline and difficultly soluble in water. The latter is probably, however, a modification of the former, and it is not unlikely that the various principles known as pseudoinulin, inu- lenin, helianthenin, and synantherin are all modifications of inulin. In examining fresh material (Fig. 92) the sections should be mounted in as little water as is necessary to enclose the section. If inulin is present it shows in the form of colorless, highly refracting globules. The latter are usually relatively small and tend to unite, forming one or more large globules. Upon increas- CELL-CONTENTS AND FORMS OF CELLS. 1^1 ing the amount of water they dissolve and are diffused among the other constituents. If fresh sections are mounted directly in alcohol, or if to the original aqueous mount strong alcohol is added, the inulin separates in the form of rod-like or needle-like crystals, which strongly polarize light. If the plant material is preserved for some days in 70 per cent, alcohol, the inulin separates in the form of sphere-crystals which adhere to the walls of the cell. This aggregate consists of concentric layers of radially arranged, needle-shaped crystals, the structure of which is more apparent upon the addition of either nitric acid or a solution of hydrated chloral. The crystal mass is insoluble in glycerin and sparingly soluble in cold water. It is soluble in warm water, warm solu- tions of glycerin and water, acetic acid, mineral acids, chlor- zinc-iodide, and ammoniacal solution of cupric oxide. With solu- tions of the alkalies it dissolves with a lemon yellow color, and with acetic acid the crystals dissolve, forming a greenish colored solution which soon fades. Tunmann {Ber. d. d. pharm. Ges., 1910, p. 577) has sug- gested the use of a solution of pyrogallol as a distinctive re- agent for the microscopic study of inulin. The solution con- sists of o.ioo Gm. Pyrogallol, alcohol 5 c.c, and 5 c.c. of hydro- chloric acid. Upon carefully heating sections treated with this reagent the cells containing inulin are colored a violet red. A simi- lar solution made with resorcin in place of pyrogallol colors inulin a cinnabar red. In taraxacum, inula, pyrethrum, and other drugs inulin occurs in the form of an amorphous mass having a more or less angular outline. The masses are highly refracting and probably consist of aggregates of small crystals similar in appearance to those of mannit found in commercial manna. Hesperidin. — Although not a carbohydrate, hesperidin is of wide occurrence and separates in the form of sphero-crystals re- sembling inulin. It is a glucoside (CooH.,50io), and it would appear, from the studies of Tunmann (Sclizveic. JVocJi. f. Chcm. u. Pharm., igog, p. 794), that, like inulin, there are several forms of it. Hesperidin, like inulin, occurs in living cells in the form of a more or less viscous fluid. Upon the addition of water, alcohol, glycerin, or solutions of hydrated chloral it separates in 152 A TEXT-BOOK OF BOTANY. the form of yellowish sphero-crystals. If the fresh plant material is placed in alcohol the crystals separate in the form of large needles, often forming branching tufts. When examined by means of the micropolariscope, they polarize light more or less strongly, depending upon how the crystals were prepared. Upon quickly dr)dng the plant material in which it occurs, hesperidin separates in the form of irregular, slightly yellowish clumps, re- sembling those of inulin found in the composite drugs of com- merce. If the material is slowly dried, the crystals are decom- posed. Crystals of hesperidin have been found in Citrus fruits ; Fig. 92. Sphero-crystals of inulin. A, parenchyma cells of the root of chicory {Cicho- ritim Inlybus) treated with alcohol: a, numerous small globules shortly after the addition of alcohol; b, a somewhat later stage, showing the fusion of many of the small globules of inulin; c, crystal formation in the globules after the alcohol has acted upon the cells for 24 hours. B, sphero-crystals resembling starch grains formed in the tubers of Dahlia vari- abilis in alcoholic material: in b, the section has been treated with nitric acid, the crystal aggregate showing a trichiten structure. — After Dippel in "Das Mikroskop." the fruit of Coc cuius laurifolius ; the leaves of Buchu, and Pilo- carpus ; species of Mentha, Hyssopus, Teucrium, Satureia, Tilia ; Conium maculatum ; Scrophularia nodosa, and stamen hairs of the flowers of Verbascum. The crystals are found especially in the epidermal cells of bracts. The crystals in the hairs of the flowers of \'erbascum are usually referred to as a sugar, but, according to the studies of Tunmann, are in the nature of a hesperidin. CELL-CONTENTS AND FORMS OF CELLS. 153 If sections are mounted in a small quantity of water and the latter replaced with dilute glycerin, followed by concentrated glycerin, then there separates in the cells a number of yellowish globules which are highly refractive (Fig. 93) ; these globules tend to unite in the center and very soon crystallize. The sphero- FiG. 93, Hesperidin. A, B, formation of sphero-crystals in the epidermal cells of the foliage leaves of Linden upon the addition of glycerin; in A the hesperidin occurs in highly refracting globules, which in B have united in a large central globule in which a crystal- aggregate has formed. C, crystals in stamen hair of the flower-bud of Verbascum. D. crystals in the cells of the upper epidermis of Hyssoptis officinalis. E, cells of the upper epidermis of the foliage leaves of the Linden. — After Tunmann. crystal consists of radiating needles, the aggregate frequently being marked by concentric lamelke, the whole being surrounded by a more or less mucilaginous wall (Fig. 93). As there are other substances in the cell the sphero-aggregate may contain some of these in the interstices. If the crystals are formed slowly and in the cold they are apt to be of a yellowish, or even dark yellow^, color, whereas if heat is employed and the crystallization 154 A TEXT-BOOK OF BOTANY. is more rapid they are nearly colorless and dissolve readily. The crystals of hesperidin are insoluble in water, alcohol, glycerin, ether, chloroform, solutions of hydrated chloral, dilute sulphuric acid and dilute or concentrated hydrochloric acid and nitric acid. •They are sparingly soluble in ammonia water and hot acetic acid. Upon the addition of either dilute or concentrated solutions of potassium hydroxide or sodium hydroxide, hesperidin dissolves, forming a yellowish solution. With concentrated sulphuric acid it gives a deep yellowish solution, which upon warming becomes a reddish-brown. Sometimes hesperidin, as in the stamen hairs of Verbascum, is colored with concentrated sulphuric acid only a light yellow. Glycogen is a carbohydrate allied to amylo-dextrin and occurs commonly as a reserve food material in the fungi and some of the Cyanophycece. It usually occurs in the form of a more or less amorphous mass in the hyphie of the fungi, but occasionally is found in definite granules resembling starch. It is supposed to arise in plastid bodies resembling leucoplastids, but its general formation is controlled by the protoplasm. In yeast it is found in large quantities, sometimes nearly filling the entire cell. CRYSTALLINE SUBSTANCES. The sugars constitute a group of crystalline principles of wide distribution. They occur in the cell-sap, from which by evaporation or on treatment with alcohol they may be crystallized out. There are chemically two main groups: monosaccharoses (formerly termed glucoses) and disaccharoses (formerly the saccharoses). Under the former are included the simple sugars containing two or more atoms of carbon and known as biose (C0H4O2), etc. Among the pentoses (C5H10O5) are rhamnose, a component of certain glucosides ; fucose, found in fucus and other brown algae, and chinovite, occurring in certain Cinchona barks. The most important subdivision of the monosaccharoses comprises the hexoses (CgHi^Oe), which include glucose and fructose, and are widely distributed ; d-mannose, found in the manna of Fraxinus Ornus and obtained by hydrolyzing cellulose, especially the reserve cellulose in the seeds of the vegetable ivory. Of the disaccharoses (C12H22O11) cane-sugar is the most im- CELL-CONTENTS AND FORMS OF CELLS. 155 portant. In this group are also included maltose, formed by the action of diastase on starch and by the action of ferments on glycogen; trehalose or mycose, found in the Oriental Trehala, ergot, Boletus edulis, and other fungi ; melibiose, occurring in Australian manna and in the molasses of sugar manufacture ; touranose, found in Venetian turpentine (obtained from Larix europcca) and in Persian manna ; and agavose, occurring in the stalks of Agave americana. Of the numerous sugars the following are likely to be met with in the microscopical study of. drugs and economic products: Dextrose (grape-sugar or dextro -glucose) is found in sweet fruits, the nectaries of the flowers, and stem's and leaves of various plants. It crystallizes in needles and varies in amount from i to 2 per cent, (in peaches), to 30 per cent, in certain varieties of grapes. It also occurs in combination with other principles, form- ing the glucosides. Levulose (fructose, fruit-sugar, or levo-glucose) is associated with dextrose, occurring in some instances even in larger quanti- ties than the latter. Sucrose (saccharose or cane-sugar j. is found rather widely distributed, as in the stems of corn, sorghum and the sugar-cane; in roots, as the sugar-beet ; in the sap o'i.certain trees, as sugar- maple and some of the palms ; in the nectaries and sap of certain flowers, as fuchsia, caryophyllus, and some of the Cactaceae ; in seeds, as almond and chestnut, and in various fruits, as figs, mel- ons, apples, cherries. In some plants, as in sugar-cane, the yield is as high as 20 per cent. It crystallizes in monoclinic prisms or pyramids, and forms insoluble compounds with calcium and strontium. Maltose is found in the germinating grains of cereals (see Malt) ; it forms colorless, needle-shaped crystals resembling those of dextrose, and forms compounds with calcium, strontium, barium and acetic acid. Trehalose occurs in some fungi, as ergot and Amanita mus- caria — the latter containing as much as 10 per cent, in the dried plant. Mannitol occurs In the form of needles or prisms and is found in the manna df Fraxinus Ornus to the extent of 90 per cent. It 156 A TEXT-BOOK OF BOTANY. is also found in some of the Umbelli ferae, as Apium graveolens, some of the Fungi and sea-weeds, and is rather widely distributed (Fig. 94)- Dulcitol, which is closely related to mannitol, is found in Euonymus europocus and in most of the plants of the Scroph- ulariaceas. Percentage OF Sugar in Plants. — No analysis is necessary to indicate that most fruits contain quite a large percentage of sugar. The following figures show the amount of sugar in some of the more common fruits, the per cent, being calculated on Fig. 94. Orthorhombic crystals of Mannitol (Mannit) obtained from aqueous solutions: A, large crystals; B, feathery aggregates of needles. dry material: Apple, 33.16 to 87.73; apricot, 7.58 to 86.21; banana, 6.20 to 21.90; blackberry, 32.67 to 40.17; cantaloupe, 0.27 to 11.98; cherry, 29.97 to 85.86; currant, 33.76 to 7549; fig, 10.00 to 29.90; gooseberry, 47.33 to 79.82; grape, including raisin, 67.82 to 83.00; huckleberry, 12.60 to 46.87; orange, 36.48 to 66.91 ; peach, 6.69 to 74.07; plum, 15.25 to 78.70; prune, 32.04 to 69.46; pumpkin, 0.15 to 11.98; and raspberry, 14.93 to 47.50. The following percentage of sugars is present in some of the cereals, common vegetables, etc. : Asparagus, 0.45 to 3.47 ; barley, 5.82 to 8.73; beet (garden), 4.20 to 31.45; beet (sugar), 3.55 to 89.61; buckwheat, 1.42 to 1.67; carrot, 3.62 to 15.30; cauliflower, 1.22 to 7.40; chestnut, 5.22 to 8.52; cocoa (cacao), 2.yy\ coffee, 0.20 to 14.50; corn, 0.96 to 6.77; cucumber, 0.72 to 1.5 1; CELL-CONTENTS AND FORMS OF CELLS. 157 lentils, 2.75; maple sap, 2 to 4; oats, 0.51 to 5.27; onions, 0.44 to 14.02; rye, 0.39 to 9.46; sorghum juice, 8.60 to 14.70; sugar- cane juice, 16.00 to 18. 10 ; spinach, 0.06 to 6.66 ; turnip ( Swedish ) , 5.05 to 9.67; sweet potato, 0.32 to 8.42; tomato, 2.53 to 3.86; vanilla, 7.07 to 9.10; wheat, 0.58 to 5.12. Honey-dew is a pathological sugar formed as a result of the stings of insects (Aphides and CoccidccX) on the leaves of certain trees. There are a number of trees the leaves of which, during the summer time, are covered with a thin layer of sugar solution. Among these may be mentioned the linden, tulip poplar, and chestnut. Honey-dew may also be formed, according to Bonnier, without the assistance of aphides, and may be seen oozing out of the stomata. It may be formed in such quantities that it may drip from trees, as in the so-called rain trees of the Tropics (see Pfeffer, '' Physiology of Plants "). The Origin and Formation of Carbohydrates. — The first visible product of photosynthesis is starch, and this is sometimes called photosynthetic starch. Investigations during recent years seem to indicate that grape-sugar or dextrose is the basal photo- synthate, and that from this starch is later formed in the plastid. This sugar is called photosynthetic grape-sugar to distinguish it from the grape-sugar found in the cell-sap of the grape, raisins, figs, etc. There is no question but that in the plastids starch is readily formed from glucose, and, vice versa, that the starch in the plastids is readily changed through the agency of the ferment, amylase, into grape-sugar. There are four factors necessary for the formation of a i)hoto- synthetic carbohydrate (starch or glucose) by the chloroplastids : ( I ) Light ; and in this condition it is the energy of the red and blue rays of sunlight which are necessary to bring about the synthesis. (2) Carbon dioxide. This compound must be present in about the normal proportions that we find it in the air, namely, 3 parts in 10,000. (3) Water is essential, and this is always pres- ent in living cells. It is by the dissociation of the CO._. and ILO and rearrangement of the atoms that carbohydrates are formed, being either starch (Q-HjoO,) or glucose (Celli.O,), with oxy- gen as a by-product. These interactions may be shown by the following equations : 158 A TEXT-BOOK OF BOTANY. 6CO2 + 5H2O = CeH.oO, + 60,. (Starch) 6CO2 + 6H2O = CeHi.Oe + 6O0. (Glucose) (4) Certain mineral substances must be present, although, appar- ently, they take no part in the photosynthetic reaction. Bokorny has shown that compounds of potassium are essential to bring about the reactions above given. Some form of iron has always been considered necessary for the development of the green pigment or chlorophyll in the chloro- plastid. While this element may seem to be necessary in water culture, it is not always essential, particularly if plants are grown under control conditions in sand. The development of chlorophyll also requires the presence of oxygen. The activity of the chloro- phyll apparatus is further influenced by other factors, viz., the maintenance of a proper temperature. It is self-evident that there is a minimum and maximum temperature at which photosynthesis is scarcely perceptible, and that there is an optimum temperature during which the activity of the chloroplastid is at its height. The latter varies with different plants, depending on the climate to which they are either indigenous or naturalized. In the Tropics the optimum temperature is somewhat higher, while in the Arctic regions it is much lower. In temperate climates the optimum varies between 20° C. (68° F.) to 30° C. (86° F.). From the facts just given it would appear that considerable is known in regard to the conditions and the substances which are concerned in the formation of photosynthetic products. On the other hand, we know practically nothing of the successive steps in the formation of either starch or glucose in the plant. Numerous experiments have been conducted and a number of hypotheses have been advanced. According to von Baeyer, the first step in the process of photosynthesis is a reduction in the CO2, formalde- hyde being formed, and this is then polymerized into a carbohy- drate, which is finally changed into dextrose. This may be repre- sented by the following equations : CO, + H,0— ^HCHO + O2 xHCHO^(CH,0)x 6(CH,0)=CeH,20e CELL-CONTENTS AND FORMS OF CELLS. 159 There are a number of other views which have been ad\ anced. Erlenmeyer, for instance, has suggested that instead of formalde- hyde being first formed, formic acid is the first product of photo- synthesis, hydrogen peroxide being hberated ; both of these then are decomposed, formaldehyde being formed according to the following equations: CO2 + H2O = HCOOH + H2O2 HCOOH + H2O2 = HCOH + H2O + O2 By the further condensation of formaldehyde as in the hy- pothesis of von Baeyer, dextrose is formed. On the other hand. Brown and Morris consider that the first carbohydrate formed is, in reality, cane-sugar, and that from this, then, dextrose and the other carbohydrates are formed. Some very interesting experiments were conducted by Berthe- lot {Compt. rend., 1898, 1900, etc.), who obtained both formic acid and formaldehyde while working with a mixture of carbon dioxide and hydrogen. Later he obtained a synthetic carbohy- drate, which on warming had an odor of caramel. Furthermore, when using an excess of carbon monoxide with hydrogen, Berthe- lot obtained a substance closely related to oxy-cellulose. Lob {Ber. d. d. pliarm. Ges., 1907, p. 117) concludes that from formal- dehyde, glycolic-aldehyde (xCHO.CHsOH) is formed; this is then followed by the formation of glyceric-aldehyde (CHoOH.CH- OH.COH), which is finally polymerized into a hexose as glucose, or even a higher carbohydrate. The Alkaloids include a group of organic bases which possess remarkable toxicological properties. They are compounds of car- bon, hydrogen, and nitrogen ; oxygen is also usually present, except in the liquid or volatile alkaloids, in which it is wanting. They are usually combined with some organic acid, as malic acid or tannic acid. In many cases the alkaloids are combined with acids that are peculiar to the genus, — e.g., aconitic acid in Aconitum, meconic acid in Papaver, etc. They are found in a large number of plants, especially among the Dicotyledons, and are rather char- acteristic for certain families, as those of the genera Strychnos, Cinchona, Erythroxylon, Papaver, etc. When present, alkaloids may be found in any part of the plant, but usually they are most abundant in certain definite regions, as roots, rhizomes, fruits, i6o A TEXT-BOOK OF BOTANY. seeds, or leaves. Furthermore, the amount is greatest at certain stages of development, as in the fully ripe seeds, more or less immature fruits, during the resting periods of roots and rhizomes, and in leaves when photosynthetic processes are most active. They occur in greatest amount in those cells which :.re in a poten- tial rather than an active condition, being associated with starch, fixed oils, aleurone grains, and other reserve products in the roots, rhizomes, and seeds. They are found in fruits in greatest amount during the development of the seed, but after the maturing of the latter they slowly disappear, as in the opium poppy and conium. The alkaloids probably arise in the protoplasm, although they may also be formed from the decomposition of protein substances. The fact that asparagine, a weak base, is usually present when the proteins are being formed from the protoplasmic substances and is also present when the proteins are being used in the growth of the plant, as during the germination of seed, would seem to indicate that both views are more or less tenable. The studies of Lotsy on Cinchona showed that alkaloids are formed in con- nection with photosynthetic processes and that they are subse- quently stored for the use of the plant. On the other hand, it is rather interesting to note that when cinchona trees are grown in the hot-house they do not produce any quinine, and, again, it is said that the conium growing in Scotland does not contain any coniine. From these observations we must conclude that alkaloids are produced only under certain conditions, and that they are not essential metabolic substances. The fact that the presence of alkaloids may be demonstrated in the thick-walled cells of the endosperm in nux vomica has led some investigators to conclude that they may arise in the cell-wall. The occurrence of alkaloids at this point is due to their imbibition by the wall, just as other soluble cell contents are absorbed, especially upon the death of the cell. MicROCHEMiSTRY OF ALKALOIDS. — The alkaloids occur in rather large quantities in a number of plants. Seldom do we find them in the form of crystals in the plant cell. Crystals of the alkaloid Piperine are not infrequently observed in the oil secre- tion cells of the endosperm of Piper nigrum (Fig. 94, ^)- The CELL-CONTENTS AND FORMS OF CELLS. i6i alkaloids form crystallizable salts and, in many instances, definite double compounds. Nevertheless, not a great amount of progress has been made in their detection and localization, either in the living plant or in economic products. The reason for this is that other substances, as calcium oxalate, may interfere with the reactions forming crystals with the reagents, so that nothing definite can be deduced. Then again, when an alkaloid is charac- terized by certain color reactions, especially if a rose or violet color is formed, it may be due to the reaction of the reagent with carbohydrates or protein substance. For this reason practically Pig. 94A. Crystals of Piperine: A, cells of endosperm showing a single oil cell (b) in which crystals of piperine have separated; (a) starch bearing parenchyma. B, piperine crystals separated from sections which have been first treated with alcohol, and to the oily globules remaining after evaporating the alcohol, a drop of distilled water has been added. In from fifteen to thirty minutes there separate needles, short rods and aggregates of piperine. — After Molisch's work on Histochemie. there are only a few instances where satisfactory results are obtained in the study of alkaloids in plant tissues. These, for the most part, have been obtained in connection with the dried mate- rials of commerce. As it is very important that these studies should be carried further, a few illustrations may be given. Hydrastis contains two alkaloids in considerable quantities which form definite salts with nitric and sulphuric acids. Fur- thermore, this plant does not contain calcium oxalate, so that the crystals formed upon the addition of mineral acids could not be of either the nitrate or sulphate of calcium, and if in other respects they corresponded to the sulphates and nitrates of the alkaloids peculiar to hydrastis, then the crystals must be salts of the alka- Toids. If sections of the fresh rhizome of hydrastis or the moist- II l62 A TEXT-BOOK OF BOTANY. ened drug are mounted directly in sulphuric acid, there separate very soon small acicular or rod-shaped crystals of berberine and hydrastine (Fig. 95). This is one of the most satisfactory of microchemical tests of the alkaloids that is known, and Leuff has shown that they can be readily determined even in the endosperm cells in the seeds of hydrastis (Pharm. Post, 1913, p. 977). Caffeine is an alkaloid which is rather widely distributed, and its presence can be *easily determined, in dried material as coffee seeds, in several ways. ( i ) It may be sublimed, the long, va^ Fig. 95. Alkaloids in Hydrastis: A, prismatic crystals which separate after a time on treatment of sections of the rhizome of hydrastis or its powder with sulphuric acid; B, the separation of needle-shaped crystals of the sulphates of the alkaloids in the paren- chyma cells of hydrastis upon treatment with sulphuric acid. silky needles of caffeine being deposited upon a watch crystal or a microscopic slide. (2) Similar crystals may separate from aqueous or hydro-alcoholic mounts of the material. (3) The most satisfactory method for the detection of caff'eine is to form a double salt with gold chloride, the crystals of which are very characteristic (Fig. 96). The test may be applied to coffee seeds, cola nuts, tea leaves, guarana, etc., as follows : Sections are placed in strong hydrochloric acid and slightly heated ; then one or two drops of a solution of gold chloride are added and the sections pushed to one side, allowing the liquid to evaporate. Near the CELL-CONTENTS AND FORMS OF CELLS. 163 edge of the residue branching groups of needles of caffeine gold chloride separate. Cocaine is another alkaloid which forms char- acteristic crystals, and the double salt of the chloride with palladous chloride is very characteristic (Fig. 97). The crystals of the latter may be prepared in the same manner as caffeine, except that to the sections of coca leaves or the powdered material a smaller quantity of hydrochloric acid is added. Fig. 96. Caffeine gold chloride; crystals formed on the addition of a solution of gold chloride to a dilute aqueous solution of caffeine. Properties of Alkaloids. — In the microchemical study of the cell-contents it is important to bear in mind that the alkaloids possess certain characteristic properties and give definite reactions with the so-called " alkaloidal reagents." The alkaloids occur in combinations with acids forming salts'which are mostly soluble in water or in alcohol, and consequently may be extn^-cted by means of these solvents. From the latter well-characterized crystals may be easily formed. The free alkaloid may be separated from solutions of their salts in water by the addition of alkalies, but it is usually important that the solutions of the latter be not in excess, as otherwise the separated alkaloids may dissolve. With 164 A TEXT-BOOK OF BOTANY. few exceptions, as Berberine and Sanguinarine, they form mostly colorless cr}^stals. Among the alkaloidal reagents giving charac- teristic precipitates the following may be mentioned. Phospho- molybdic acid (Sonnenschein's Reagent) gives with nearly all of the alkaloids a yellow, insoluble amorphous precipitate. Potas- FiG, 97. Cocaine: A, monoclinic crystals cf cocaine; B, orthorhombic crystals of co- caine hydrochloride; C, monoclinic crystals of cocaine hydrochloride and palladous chloride; D, skeleton aggregates of cocaine hydrochloride and palladous chloride. sium mercuric iodide (Mayer's Reagent) precipitates many of the alkaloids in even dilute solutions, the precipitates being usually yellowish-white and more or less fiocculent. Wagner's Reagent, or iodine dissolved in a solution of potassium iodide, is another reagent that precipitates nearly all the alkaloids. The precipi- tates are of a reddish or reddish-brown color, and are more readily formed in acidulated solutions. From alcoholic solutions CELL-CONTENTS AND FORMS OF CELLS. lb: crystalline double compounds may be formed. Picric acid forms characteristic crystals with a number of the alkaloids. Wormley's Reagent, or a soKition of bromine in hydrochloric acid, gives definite microscopic crystals with some of the alkaloids, as atro- pine, hyoscyamine, and veratrine. Auric chloride and platinic chloride both form characteristic double salts with a number of the alkaloids. There are a number of other reagents which are used in the study of the localization of alkaloids in plants. Most of these depend upon certain color reactions. While it is true that the alkaloids give rather striking colors with certain reagents, yet, as a rule, they are of little value except when the alkaloids are in a pure condition. This same objection holds, but with some- what less force, to the employment of the alkaloidal reagents just mentioned. Families Yielding Alkaloids. — It is very difTficult to deter- mine from the literature of the analyses as to how widely distrib- uted alkaloids are in plants. Time and again principles, which give definite reactions with certain alkaloidal reagents, are subse- quently shown to be other than alkaloids. In enumerating the families in which alkaloids occur we do not mean to say that they are lacking in the families not mentioned here. Alkaloids are seldom found in the Cryptogams, being confined, with few exceptions, to the poisonous fungi, as Amanita of the Agaricacae. Among the Monocotyledons they are found in the Palmar and the Liliacege. They are more widely distributed in the Dicoty- ledons, occurring in the following families : Piperace^e, Chenopo- diaceae, Ranunculaceae, Berberidaceae, Menispermaceae, Lauraceae, Papaveracese, Leguminos?e, Erythroxylaceae, Rutace?e, Acjuifolia- ceae, Sapindaceae, Sterculiaceae, Punicace?e, Um1)elli ferae, Logania- ce«, Apocynaceae, Solanaceae, RubiacCcC, and Lobeliaceae. The Amount of Alkaloids in plants varies under different climatic conditions and is also very much influenced by culti- vation (see chapter on '* Cultivation of Medicinal Plants"). For these reasons there is a wide range in the alkaloidal content of drug products, and, as the alkaloids are among the most poisonous constituents known, the various pharmacopoeias have set alkaloidal standards. At the International Conference for the Unification of Pharmacopoeial Formulae for Potent Medicaments held in Brus- i66 A TEXT-BOOK OF BOTANY. sels in 1902 a protocol was prepared designating the strength of the various galenicals. Unfortunately, a standard for the alka- loidal content of drugs was not also established, and consequently in the several pharmacopoeias there is still some variation in drug standards. For percentage of alkaloids in different drugs and their variation, consult Volume II, treating of Pharmacognosy. Chemical Classification of Alkaloids. — The chemical study of the alkaloids shows that each plant contains not one but a number of alkaloids, cinchona bark and the opium poppy yield- ing not less than twenty different alkaloids. As their chemical constitution is not well known, it is customary even for the chemist to group them into certain natural classes, as the alkaloids of conium, tobacco alkaloids, the cinchona alkaloids, opium alka- loids, etc. They may also be grouped into certain fundamental groups, according to their nuclear structure derived from their probable constitution. While the natural classification may be more convenient, it will be replaced by a classification based on chemical constitution when our knowledge of this .class of sub- stances is extended. From studies thus far made the following groups of alkaloids may be recognized : Pyridine Group. — Alkaloids derived from pyridine (C5H5N) are found in Conium maculatum, Piper nigrum, and other species of Piper, Trigonella Fccnum grcccum, Areca Catechu, Beta vul- garis, Nicotiana Tabacum, Pilocarpus Jahorandi and other species of Pilocarpus, Lupinus, Laburnum, and other genera of the Leguminoscc. This group includes the liquid or volatile alkaloids. Pyrrolidine Group. — Derivatives of Pyrrolidine (C4H8NH) occur in Atropa, Hyoscyamus, Datura, Scopolia and other genera of the Solanacecc, Erytliroxylon Coca, and Punica Granatiim. QuiNOLiNE Group. — Alkaloids with a Quinoline nucleus (C9H7N) are obtained from cinchona bark and nux vomica. IsoQUiNOLiNE Group. — IsoquinoHue is isomeric with quino- line ; alkaloids with this nucleus are found in the opium poppy, Hydrastis canadensis, Berberis vulgaris, Menisperuuun canadense and quite a number of genera in the closely related families of Ranunculacecc, as well as in some other plants. Phenanthrene Group. — Morphine and codeine, closely re- CELL-CONTENTS AND FORMS OF CELLS. 167 lated alkaloids in opium, probably contain the Phenanthrene nucleus (Ci^Hjo). Purine Group. — Cafifeine, the characteristic alkaloid of coffee, tea, and guarana, as well as theobromine associated with caffeine in cacao and kolanut, are derivatives of Purine (C-.H^X). Amino-acid Group. — Asparagine, or the monamide of aspartic acid, is very widely distributed throughout the plant kingdom. Consult J. W. Bruhl, "Die Pflanzen-Alkaloide " ; A. Pictet, '' The Vegetable Alkaloids," translation by H. C. Biddle ; O. A Oesterle, '* Grundriss der Pharmakochemie." Asparagine (C4H8N2 + H2O) (/8-asparagine, the monamide of aspartic acid) is an amido compound which is most widely distrib- uted throughout the vegetable kingdom. It is found not only in reserve organs as the tubers of the potato and dahlia, the roots of althaea, belladonna, etc., and the seeds of the chestnut tree, but it also occurs in young shoots as of asparagus and in peas, beans, and other members of the Leguminosse. Asparagine has also been detected in some of the fungi as the Agaricineae and cer- tain of the Myxomycetes. Unlike certain derivatives of urea, it is a plastic product playing a very important role in plant metabolism. On account of its crystalline character and solubility in water, it is classed among the translocatory substances, appearing not only when proteins are being utilized by the plant, but when they are being formed. The crystals of asparagine are formed rather easily from the expressed juices of young shoots, and may be obtained even in sections upon mounting them in glycerin. The crystals vary in length from 0.3 mm. to 15 mm. (Fig. 98). Asparagine occurs in two forms, one of which is laevo-rotatory and the other dextro-rotatory; the former is the one usually present in plants. At 17.5 ° C, i part of asparagine is soluble in 47 parts of distilled water; at 98° C, i part is soluble in 1.9 parts of distilled water. The Glucosides or Glycosides are a class of plant substances which under the influence of ferments split up into a number of substances, one of which is always glucose (dextrose) or an analo- gous compound. Van Rijn has proposed the class name Glykoside for all substances of this group, restricting the name glucoside to those which yield glucose on hydrolysis. The glucosides are i68 A TEXT-BOOK OF BOTANY. always associated in the plant cell with the special ferments which are capable of decomposing them. There are other sub- stances which have the property of breaking up the glycosides, viz., dilute acids and alkalies. Of tlie mineral acids, dilute sulphuric acid and dilute hydrochloric acid are the most effective. They do not, however, always produce the same results on the same glucoside, as sometimes one acid works better than the other. Some glucosides are hydrolyzed by the use of strong Fig. 98. Microphotograph of the rhombic prisms of Asparagine (amido-succinamic acid), which is rather widely distributed in the vegetable kingdom. From aqueous solution the smaller crystals are combinations of base and prism (a) ; one or both of the acute angles may be truncated on the faces of the brachydome (b) ; in the larger crystals (c) the brachy- dome is more developed and is either equidimensional or elongated on the a -axis. organic acids, as oxalic acid and citric acid. In view of the fact that most glucosides require the presence of water in addition to the presence of the ferment to produce an interaction, they are looked upon as ether or ester derivatives. This view is strengthened by a careful study of the glucosides which have been prepared synthetically, but it is not known in what manner the glucoside is united with the other compounds making up the. natural glucosides. CELL-CONTENTS AND FORMS OF CELLS. 169 Distribution of Glucosides. — This class of substances has only been isolated in the Dicotyledons, being present in the I'ina- ceae, Graminese, Liliaceae, Iridace?e, SalicacccT, FagacccX, Moraces, Urticacese, Proteacese, Santalacese, Polygonacese, Caryophyllacea?, Ranunculacese, Magnoliacese, Calycanthace?e, Anonace^e, IMoni- miaceae, Cruciferse, Saxifragaceae, Rosaceas, Legiiminosa^, Tropcco- laceae, Linaceae, Rutaceae, Simarubaceae, Polygalaceae, Anacar- diaceae, Corynocarpaceae, Aquifoliace^e, Celastraceje, Hippocas- tanaceae, Sapindace^e, Rhamnaceae, Vitaceae, Tiliaceae, Alalvace^, Theaceae, Dipterocarpaceae, Cistaceae, Caricaceae, Datiscace^, Thymelasaceae, Lythraceae, Punicaceae, Combretaceae, Myrtaceae, Araliaceae, Ericaceae, Primulaceae, Sapotaceae, Oleaceae, Logania- ceae, Gentianaceae, Apocynaceae, Asclepiadaceae, Convolvulaceae, Hydrophyllaceae, Boraginaceae, Verbenaceae, Labiat^e, Solanaceae, Scrophulariaceae, Bignoniaceae, Orobanchaceae, Globulariaceae. Rubiaceae, Caprifoliaceae, Cucurbitaceae, and Compositae. Chemical Classification. — The natural glucosides may be grouped either according to the nature of the sugar formed on hydrolysis or their probable organic derivatives. Most glucosides yield either dextrose or rhamnose. (i) Of the dextrose-gluco- sides the following may be mentioned : ^sculin, amygdalin, arbu- tin, coniferin, fraxin, gaultherin, gossypetin, gynocardin, indican. iridin, linamarin, phloridzin, populin, prulaurasin, ruberithrinic acid, salicin, sambunigrin, saponarin, serotin, sinalbin, sinigrin, and syringin. (2) Of the rhamnose-glucosides the following may be mentioned : Baptisin, datiscin, f rangulin, fustin, glycyphyllin, and quercitrin. (3) There are a few glucosides which yield peculiar sugars, as apiin, which on hydrolysis gives apiose and dextrose; barbaloin forms d-arabinose ; convolvulin yields rho- deose and dextrose ; digitalin forms digitalose and dextrose^ digitonin forms galactose and dextrose ; digitoxin yields digi- toxose ; gentiin yields xylose and dextrose ; hesperidin forms rhamnose and dextrose, which are also formed from naringin and rutin ; robinin forms galactose and rhamnose ; strophanthin yields rhamnose and mannose ; vicianin forms arabinose and dextrose ; and xanthorhamnin yields galactose and rhamnose. Rosenthaler (Pharm. Zentralh., 1907, p. 94) ^las attempted to group the glucosides, according to the constitution of the non- I70 A TEXT-BOOK OF BOTANY. sugar substance formed on the hydrolysis of the glucoside. He has given the non-sugar substances the class name of " Aglykone," and groups the glucosides accordingly into the following three classes: I. Glucosides without Nitrogen Aglykones. II. Gluco- sides with Nitrogen Aglykones. III. Glucosides with Nitrogen and Sulphur Aglykones. Class I is further subdivided as its members yield aliphatic, aromatic, or other derivatives ; each of these again is further subdivided into a number of subgroups. Among the aliphatic aglykones are included the glucosides jalapin and convolvulin. The glucosides with aromatic aglykones are subdivided as follows: (A) Those yielding benzol derivatives and include arbutin, salicin, populin, gaultherin, etc. (B) Deriva- tives containing the styrol nucleus include coniferin, daphnin, aes- culin, scopolin, fraxin, naringin, and hesperidin. (C) Derivatives containing anthracene in their constitution, as f rangulin, morindin, and the glucosides of emodin, rhein, etc. (D) Glucosides which are derivatives of flavon include apiin, fustin, quercitrin, rutin, xanthorrhannin. II. The glucosides with Nitrogen Aglykones include a number of cyanogenetic glucosides, of which amygdalin is the representative. III. The glucosides with Nitrogen and Sulphur Aglykones include sinigrin and sinalbin found in the genus Sinapis and other genera of the Cruciferae. (Consult J. J. L. van Rijn, " Die Glykoside "; O. A. Oesterle, " Grundriss der Pharmakochemie.") Properties of the Glucosides. — Like the alkaloids, some of the glucosides are highly toxic. Among those that possess a high degree of toxicity may be mentioned convallamarin, digitalin, scil- lain, strophanthin, sapotoxin, etc. They are soluble in water, alcohol, ethyl acetate, and chloroform, and insoluble in ether. The aqueous solutions are neutral or but faintly acid. Glucosides may be separated from solutions of salts of the alkaloids owing to the fact that they are soluble in chloroform and some other of the immiscible solvents, providing the solution is slightly acid. Most of the glucosides form well-developed crystals and may be studied with a petrographical microscope (Fig. 99). There is no special class of reagents, as with the alkaloids, used in their detection ; on the other hand, some of them give strikingly distinct color reactions whereby they may be detected in the CELL-CONTENTS AND FORMS OF CELLS. 171 tissues of the plant. With very few exceptions, however, the color reactions are not satisfactory. Micro-Chemistry of Glucosides. — Although the glucosides upon" extraction from the plant tissues form well-defined crystals (Fig. 99), they have not been identified as such in the plant. A few have been identified by giving distinct color reactions with certain reagents. The glucoside strophanthin can be detected in the seeds of Strophanthus hispidus. This glucoside is colored a brilliant green with sulphuric acid and is confined to the cells of the endosperm. The test is carried out as follows: Sections are mounted first in water and then transferred to a drop of sulphuric acid contained on the sam^ slide, when the cells con- taining strophanthin are colored a bright green. Saponin is an- other glucoside which, it is stated, may be readily detected in plant cells, giving a reddish color reaction with sulphuric acid. Lafon's reagent also may be applied for the detection of saponin ; this consists in the use of two solutions: (a) equal volumes of alcohol and sulphuric acid; (b) a very dilute solution of ferric chloride. The sections are placed in solutions (a) and then a drop of solution {b) is added. Cells containing saponin are col- ored red, changing to violet, becoming brownish-blue, or brown upon the addition of ferric chloride. Coniferin, the glucoside found in the cells of pine and other Coniferous trees, is colored red with sulphuric acid ; it also gives a characteristic reaction on treatment of the section first with phenol, followed by sulphuric acid or hydrochloric acid, it becoming a deep blue almost instantly. The Saponins are a group of glucosides which possess the common property of forming a froth on shaking their aqueous solutions, and are present in the " soap-plants," which have been widely used as detergents. The saponins also dissolve the red blood-corpuscles, and for this reason are considered to be toxic substances. They have been found in the cell-sap of a large number of plants, occurring in parenchyma cells and medullary rays of roots and stems, the secretion cells and secretion reser- voirs of leaves, and all parts of fruits and seeds. A large number of principles have been isolated from different plants, some of these being given distinct names, but the majority of them are homologous substances having the general formula CJ^.^.fi^^. 172 A TEXT-BOOK OF BOTANY. On account of some of the saponin-containing plants being added to beverages and used as emulsifying agents, the toxicity of a number of the saponins has been studied, those which are highly poisonous being known as sapotoxins. The following are some of the plants which contain sapotoxin : Quillaja Saponaria (9 per cent.), Agrostemma Githago (6.5 per cent.), Saponaria officinalis (4 to 5 per cent.), and Poly gala Senega (2.5 per cent.). Saponins have been found in more than a hundred different plants, including one or more genera of the following families: Liliaceae, Dioscoreacese, Araceae, Chenopodiaceae, Phytolaccaceae, Caryophyllaceae, Berberidacese, Magnoliaceae, Ranunculaceae, Bixacese, Theaceae, Rutace^e, Zygophyllacese, Meliaceae, Simaru- bacese, Sapindaceae, Hippocastanaceae, Melianthaceae, Polygalaceae, Pittosporaceae, Rhamnaceae, Saxifragaceae, Passifloraceae, Big- noniaceae, Myrtaceae, Rosaceae, Leguminosae, Primulaceae, Sapo- taceae, Oleaceae, Solanaceae, Scrophulariaceae, Rubiaceae, and Compositae. Gluco-alkaloids represent a class of compounds intermediate between the alkaloids and glucosides, possessing characteristics of each. To this class belong achilleine, found in various species of Achillea, and also solanine, found in a number of species of Solanum. Functions of Alkaloids and Glucosides. — In the growth of the plant there must not only be an adaptation to the external conditions and provision made to protect the plant against tem- pests, drought, excessive light, extreme temperatures, etc., but the plant must protect itself from diseases as well as from the depredations of animals. As a rule, plants, particularly of the tropics, depend on their own power to repair any injury to which they may be subjected. Nevertheless, there are many plants which produce poisonous substances, and these are usually sup- posed to have the function of protecting them from various dis- eases, as well as attack by herbivorous animals. ^lany of the alkaloids and glucosides are apparently aplastic substances, — i.e., are formed either occasionally or continually as unavoidable by- products of metabolism, or are produced for special purposes. Some of these principles, as asparagine, an alkaloid, and hesperi- Fig. 99. Salicin. Orthorhombic crystals from alcoholic solution. Fig. ioo. Cocaine hydrochloride. AKgregates from aqueous solution. CRYSTALS IN POLARIZED LIGHT (Crossed nicols). 1 CELL-CONTENTS AND FORMS OF CELLS. 173 din, a glucoside, are not only products of constructive metabolism, Hbut are entirely reassimilated. SuBLiMAELE PRINCIPLES. — Quite a uumbcr of plant principles are capable of being sublimed. Not only is this true when they are in the pure state, but also when they are associated with other compounds in the plant cell. This fact is of very great interest in the examination of commercial articles and also in the study of the localization and distribution of plant constituents. The method of procedure is very simple, and a small quantity of material only is necessary, usually from 0.020 to 0.050 Gm. being required. In the study of leaves a fragment about 10 square millimeters is sufficient. The material is dried, either cut up or more or less comminuted and placed in a small watch crystal, the latter being covered either with a slide or another watch crystal for the deposi- tion of the sublimate. The watch crystal containing the material is carefully heated either on a sand bath or on a bath containing sulphuric acid (Figs. loi to 104). Rosenthaler {Ber. d. d. pharm. Ges., 1911, p. 338) has sug- gested in the examination of powdered drugs a specially con- structed apparatus. A small quantity of the powder is intro- duced by means of a long funnel into a suitable tube, so that n@ne of it comes into contact with the side walls. The powder should be covered with a layer of asbestos to prevent any of it being carried up mechanically. The tube is closed with a rubber stopper having two holes, one of which carries a doubly bent tube leading to a small vessel acting as a receiver, the other carrying a tube con- nected with an air-pump. The air is exhausted and the tube con- taining the drug is heated in a bath of sulphuric acid or paraffin. A sublimate will form in the upper part of the tube containing the material, and distillation products will pass into the tube acting as a receiver and can be tested with various solvents and reagents. Plants containing thein, vanillin, and coumarin may be examined by direct sublimation in a watch crystal. Substances which yield tarry distillate, as cinchona, hydrastis, piper, etc., probably are better examined using the apparatus described by Rosenthaler. Tunmann (Ber. d. d. pharm. Ges., 19 11. p. 312) examined a number of plants of the Ericaceae and found, by the microsublima- 174 A TEXT-BOOK OF BOTANY. tion method, that they contained arbutin. The latter is a rather widely distributed glucoside in this family and yields upon treat- ment with solutions of emulsin or hydrochloric acid the sublimable principle hydrochinon. The latter forms prisms and plates and may be further examined with acetone solution, dilute solutions of Fig. ioi. Alkaloids of Hydrastis obtained by microsublimation. The method fol- lowed by Tunmann is to mix from o.oio to 0.050 Gm. of powdered Hydrastis with a drop of fvater upon a glass slide and heat to a temperature of 80° to 95° C. The sublimate consists jf a number of radiating particles in which different types of crystals very.soon separate (A). The microsublimate may be further treated with alcohol and a solution of potassium iodide, when crystals of hydrastine (B) and needle-shaped crystals of berberine (C) form. — After Tunmann in Gehe & Co.'s Handelsbericht, 191 2. ferric chloride and ammonia water. Arbutin occurs in the leaves of Arctostaphylos Uva-ursi, Vaccinium Myrtillus, Kalmia angustifolia, and Pyrola rotundifolia. Rosenthaler obtained definite crystals in the microsublimation or pyro-analysis of the following drugs : cinchona, uva-ursi, f ran- CELL-CONTENTS AND FORMS OF CELLS. 1/5 gula, rhamnus purshianus, rheum, Hydrastis, opium, cubeba, piper, anisum, senna, radix scammoniae, chrysarobinum, rheum rhaponti- FiG. 102. Microsublimate crystals of alkaloids in Hydrastis: A, White crystals of tiydrastine formed upon the addition of chloroform to the sublimate. B, Type crystals obtained on the microsublimation of pure hydrastine hydrochloride. C, Type crystals obtained on the microsublimation of pure hydrastinine hydrochloride. D, Crystals of hydrastine formed upon the addition of water to the amorphous and crystalline sublimate obtained in the heating of powdered Hydrastis. E, Resublimed crystals of hydrastin obtained from the chloroformic solution of the microsublimate. — After Tunmann in Gehe {c Co.'s Handelsbericht, 1912. cum, jalapa, coca, stramonium, kamala, cousso, auranlii fructus cortex, guarana, cacao, kola, cantharides, podophyllum, radix canaigre, and kava-kava. (Consult Figs. loi to 104.) 176 A TEXT-BOOK OF BOTANY The drugs thus far studied may to some extent be grouped according to the sublimable constituents which give characteristic reactions, i. Thein- or caffeine-containing drugs, as coffee, tea, cacao, and guarana. 2. Arbutin-containing drugs or those yielding hydrochinon, as uva-ursi and other Ericaceae. 3. Drugs yielding oxymethylanthraquinbne and giving a distinct purple color with solutions of the alkalies, as rhamnus purshianus, frangula, rheum, senna, etc. B /fl^ 08 0 ^J^ ^' ° 8 All ^""°^^'-^'^ 'amellation and refraction of the waH ° """'' ^ ^'■""■'- 2'J2 A TEXT-BOOK OF BOTANY. Conducting cells or mestome Include those cells which are chiefly concerned in the transferral of either crude or assimilable Fig. 142. Development of spiral bands in the mechanical cells of young fruits of Fegatella conica (Hepaticae): I, young cell with vacuoles and small starch grains; II, portion of an older cell showing formation of large vacuoles in the protoplasm, the strands of which are arranged in a left-hand spiral; III, showing spiral arrangement of protoplasm; IV, portion of cell as in III treated with a sugar solution and showing plasmolysis of protoplast; V, showing formation of band; VI, a cell as in V treated with sugar solution, sho-ving the protoplasm arranged along the thickened portions of the wall where the bands are forming; VII, the mature cell showing lignified spiral bands. — After Dippel in "Das Mikroskop." food materials. The more or less crude inorganic materials are carried from the root through the woody portion of the stem to CELL-CONTENTS AND FORMS OF CELLS. 2^-^ the leaves, and from the leaves the products of photosynthesis, as well as other plastic substances, are distributed through some of the tissues of the bark to other parts of the plant. The tissues or elements of the wood which conduct food materials are of sev- eral forms and include tracheae or vessels (also called " ducts "), tracheids, and conducting parenchyma; and the elements of the bark which transport the assimilable materials comprise the lep- tome and conducting parenchyma (Fig. 141). Water-conducting elements (tracheal elements) comprise the vessels (tracheae) and the tracheids, which resemble each other, except that the latter are single cells of prosenchymatic shape, while the former are very long tubes, varying from cylindrical to prismatic in shape, and consist of long rows of cells which are superimposed length- wise, the transverse walls being usually obliterated. A s a c R _ « ^^ ^^ Fig. 143. Forms of tracheae or vessels. A. — Longitudinal section of stem of Cticurbita Pepo showing various forms of tracheae: A, annular; S, spiral; D, double spiral; C, close annular; R, reticulate. B. — Tracheae in glycyrrhiza rhizome: W, wall; B, bordered pores; P, oblique simple pores. The tracheae or vessels are formed by the disintegration and removal of the transverse walls between certain superimposed cells, forming an elongated cell or tube, which occasionally retains some of the transverse walls (Figs. 142-144). The longitu(hnal walls are relatively thin and consist of lignocellulose, giving pro- 'iiounced reactions with phloroglucin or aniline sulphate. Four types of vessels or tracheae are known : annular, spiral, reticulate, and porous. Those having the thickenings in the form of horizontal or oblique rings are known as annular trache.^; those having the thickenings in the form of spirals, which usually run from right to left, are known as spiral trachea; those having the thickenings in the form of a reticulation are known as 18 274 A TEXT-BOOK OF BOTANY. RETICULATED TRACHE.E, and those With spherical or oblique slit pores are known as porous trachea or vessels (Figs. 142-144). In those vessels in which but few of the transverse walls are obliterated, the walls are marked by both simple and bordered Fig. 144. Types of tracheae or vessels. A, vessels with annular and spiral thickenings .in Phlox Carolina; B, longitudinal section through fibrovascular bundle in aconite, showing porous (p) and spiral tracheae (t), bast fibers (b), and some of the collenchyma cells (c) ; C, longitudinal section showing reticulate tracheee in scopolia; D, longitudinal section of the woody part of the rhizome of Spigelia, showing tracheae (t), tracheids (h), tracheae (r) with yellowish-brown, gum-like masses; E, portion of xylem of stem showing in Hyos- cyamus tracheae (t) with bordered pores and wood fibers (w), with simple oblique pores. pores, wdiich latter are described under tracheids. Vessels contain water, water-vapor, and air; in some cases they contain sugar, tannin, mucilage^ or resin. CELL-CONTENTS AND FORMS OF CELLS. 275 The tracheids are intermediate in character between trachccC and Hbriform, resembhng the former in possessing bordered pores (Fig. 145) and scalariform thickenings; and the latter in being true cells, which are usually elongated and quite thick-walled, the walls giving distinct reactions for lignocellulose with phloro- glucin or aniline sulphate. One of the chief characteristics of tracheids is the bordered PORES (Fig. 145). These differ from simple pores in that the wall surrounding the pore forms a dome-shaped or blister-like m Y 5 V m ^ Fig. 14s Bordered pores of the tracheids of the wood of Abies alba as viewed in longitudinal section: m, middle lamella; v, i, middle and inner layers of walls of contigu- ous cells; C, pore-canal through which sap passes from one cell to another; L, dome- shaped cavity of pore; S, separating wall or closing membrane which is usually thickened in the middle as shown at t. In older cells the separating membrane is broken as shown in the lower pore in figure 2. At the right in figure 4 is shown a surf -ce view of a bordered pore, the dotted lines indicating the relation of the circles to the structure of the pore. — After Vogl. protrusion into the cell. On surface view the pores are either circular or elliptical in outline, the dome being circular or, if the pores are numerous and arranged close together, more or less polygonal (Figs. 143, 144). The number and distribution of bordered pores in the Coni- ferse are quite characteristic for some of the genera, and may be studied in any of the pines, the pores being most numerous in the radial walls (Fig. 69). 276 A TEXT-BOOK OF BOTANY. The leptome or sieve is distinguished from the other con- ducting elements in that the walls are thin and are composed of cellulose (Fig. 146). It consists of superimposed elongated cells, the transverse walls of which possess numerous pores which are supposed to be in the nature of openings, permitting of the Fig. 146. Different forms of sieve pores: I, portion of sieve tube of Bryonia alba, II of Cucurbita Pepo, A longitudinal section and B in transverse section; III, portion of a sieve cell of Larix europcEa showing round sieve pores; IV, an old sieve plate in Bryonia alba treated with chlor-zinc-iodide, showing the striated callous plates (c), (z) cell-wall, (s) sieve plate, (i) contents of sieve tube, (h) cell membrane, (c) callous plates. — After Dippe) in "Das Mikroskop." direct passage of the contents from one cell to the other. This transverse wall, which may be either horizontal or oblique, is known as the sieve plate, and the thin places as pores of the sieve. The sieve plates are sometimes also formed on the longi- CELL-CONTENTS AND FORMS OF CELLS. 277 tudinal walls. When the activities of plants are suspended during the winter, there is formed on either side of the sieve plates a layer of a colorless, mucilaginous substance, known as callus, which has somewhat the appearance of collenchyma, but is colored brownish by chlor-zinc iodide. The sieve cells contain an albuminous substance somewhat resembling protoplasm ; in some instances starch grains have also been found. When the activities of the sieve tubes have ceased, they be- come altered in shape, and are then known as altered sieve. In the drying of plants a similar alteration is produced, and the sieve of vegetable drugs is referred to as *' obliterated " sieve. Protecting cells include those cells which are located on the outer parts of the plant. The function of these cells is to lessen the rate of transpiration, or the giving off of water ; to furnish protection against changes of temperature, and to protect the inner tissues against the attack of fungi and insects ; they also have a mechanical function (Figs. 147, 157). Depending principally upon their composition, these cells may be divided into two classes, namely, epidermal cells and cork cells. The epidermal cells constitute the outermost layer of the plant. They contain cytoplasm, but the plastids in some instances are wanting; in petals, etc., they also contain dissolved color- ing principles ; and on account of the relatively large amount of water which they contain they are classed among the important water-reservoirs of the plant. The outer walls are principally characterized by one or more lamella of cutin, these uniting to form a continuous wall. The cutin is often associated with wax, this constituting the bloom of fruits ; less frequently such inorganic substances as calcium car- bonate, calcium oxalate, and silica are present, and not infre- quently mucilage is present, as in the walls of certain seeds (Fig. 119,^^)- On surface view the form of these cells varies from nearly isodiametric to oblong; they may also be polygonal or branched. In transverse section their radial diameter is much the shorter. In some instances the inner and side walls are considerably thick- ened, as in the seeds of a number of the Solanacese (Fig. 136, A). 278 A TEXT-BOOK OF BOTAXY. The epidermis usually consists of a single layer of cells, but may have additional layers underneath forming the hypodermis, as in the upper surface of the leaves of species of Ficus (Fig. 113) ; Fig. 147. Stomata and water-pores. A. — Transverse section through lower surface of leaf of stramonium: stoma, with guard cells (G), containing cytoplasm, nucleus and chloroplastids; N, surrounding cells; A, intercellular cavity usually filled with cell-sap or watery vapor; E, epidermal cells; M, mesophyll. B. — Surface section of upper surface of leaf of Viola tricolor showing four stomata. C. — Surface section of under surface of leaf of Viola tricolor showing five stomata. D. — A section through the margin of the leaf of Viola tricolor showing a tooth with three water-pores. E. — A water-pore of Viola tricolor in surface section. in some instances the hypodermis undergoes a mucilage modifica- tion, as in the leaves of buchu. Stomata. — Distributed among the epidermal cells are pairs of crescent-shaped cells known as a stoma, and having an open- CELL-CONTENTS AND FORMS OF CELLS. ^79 ing or pore between them, which leads to a cavity beneath it. The two cells of the .stoma are known as guard cells (Fig. 147, C ). The adjoining walls of the guard cells are alike in transverse sec- tion, but the cells vary in shape in different plants. The guard cells are more or less elastic, and when the cells are turgescent, as when there is an abundance of water and root pressure is strongest, the contiguous walls of the cells recede from each other, forming an opening between them, thus permitting the exit of the excess of water taken up by the plant and the exhalation of the oxygen given off during assimilation, as well as the intake of the carbon dioxide used in photosynthesis. On the other hand, when the amount of water in the plant is reduced below the normal and the plant shows signs of wilting the guard cells flatten and the open- ing or pore is closed (Fig. 214). The cells beneath the stoma are loosely arranged, so that the air containing carbon dioxide may be readily dift'used to the cells containing the chloroplastids. The guard cells may be slightly raised above or sunk below the surrounding epidermal cells, the number of the latter being characteristic for certain plants. (Compare Figs. 147, 211-218. ) Stomata occur in the largest numbers on the blades of foliage leaves, being more numerous on the under surface, except in aquatic plants, where they occur only upon the upper surface. Water Pores. — Near the margin of the leaf and directly over the ends of conducting cells, not infrequently occur stomata, in which the function of opening and closing is wanting, and which contain in the cavity below the 'opening water and not air, thus differing from true stomata (Fig. 147, D, E). These are known as WATER PORES, and they give off water in the liquid form, the drops being visible on the edges of the leaves of nasturtiums, fuchsias, roses, etc., at certain times. Plant Hairs. — The epidermal cells are sometimes specially modified centrifugally, giving rise to papillse, to which the velvety appearance of the petals of flowers is due; in other cases this modification is in the form of hairs or trichomes (Figs. 148-155). These may be unicellular or multicellular, and in addition the latter may be glandular or non-glandular. Glandular hairs possess a head-like apex, consisting of one or more cells, and they secrete oil, mucilage, and other substances (Figs. 124. 125. 149. 150). 2So A TEXT-BOOK OF BOTANY. In the examination of technical products, as also in taxonomic work, the study of plant hairs is very important. They show a great diversity in form in not only genera and families but even in related species. They vary considerably in their distribution Fig. 148. Mostly non-glandular hairs and a few of the small glandular hairs covering the surface of the fruits of several species of Rhus: g, hairs on Rhus glabra, being more or less broadly top-shaped or carrot-shape to spatulate and occasionally narrow elliptical and from o.ioo to 0.400 mm. in length; b, hairs on Rhus typhina, being long and needle-like, varying from 0.750 to 1.500 mm. in length; c, hairs of Rhus glabra borealis, being intermedi- ate between those of Rhus glabra and Rhus typhina, varying from elongate spatulate and narrow cylindrical to needle-shaped, and from o.ioo to i.ooo mm. in length. not only in related species, but sometimes in varieties of the same species they show marked variation in size and form. In some natural hybrids intermediate forms of hairs of the parent species CELL-CONTENTS AND FORMS OF CELLS. 281 are found. This was pointed out by Kraemer in some studies on Rhus glabra and Rhus typhina (Amer. Jour. Phann., 1913, p. 404), in which a herbarium specimen in the New York liotanical Garden and labelled by Britton as Rhus glabra borealis shows hairs which in form and size are intermediate between those of R. glabra and R. typhina (Fig. 148). Plant hairs may be divided into two principal groups: i. Glandular hairs, or those in which the summit consists of one or more cells which secrete beneath the cuticle either mucilage, oils, or oleo-resins, and the summit of the hair possesses a more or less globular form. IL Non-glandular hairs, or those in which the summit of the hair consists of one or more rounded or pointed cells in which no secretion is formed beneath the cuticle. Glandular Hairs may be divided into five different groups : 1. Unicellular glandular hairs consist of a single tubular cell, the upper portion being more or less swollen and rounded (Fig. 149, A, B). Hairs of this type occur in the Eupliorbiaceae, in which they more or less resemble Papillae. In the Compositse they contain a latex and appear to be connected with the laticifer- ous vessels. They also occur in the Anacardiacese, Cornaceae, Geraniaceae, Leguminosae, Malvaceae, Menispermaceae, Onagraceae, Piperaceae, Ranunculaceae, Tiliaceae and Zygophyllaceae. 2. Multicellular glandular hairs consist of a number of forms ; either they are differentiated into a stalk and a head, or the stalk may be wanting when the hair has a spatulate or clavate form. These are often very characteristic for certain families, as the glandular hairs in the Labiatae (Fig. 124), which possess a short stalk and a head portion with eight cells, the cuticle being raised like a bladder owing to the great accumulation of secretion. There are a great many types of multicellular glandular hairs (Fig. 149). They may be uniseriate, i.e., consisting of a series of cells with either a unicellular head (Fig. 149, C, E, K, M), as in the Meni- spermaceae, Araliaceae, Malvaceae, Caryophyllaceae, Geraniaceae, etc., or they may be bicellular (Fig. 149, D, F, H, J, L, O), as in the Cruciferae. The heads may consist of two to four cells (Fig. 149, G, F, F), as in the Burseraceae, or eight cells, as in the Labiatae (Fig. 149, JV). Multicellular glandular hairs have been found in the following families : Aceraceae, Anacardiaceae, Araliaceae, Be- 282 A TEXT-BOOK OF BOTANY. Fig. 149. Various types of glandular hairs. Unicellular hairs on Julocroton fus- ccscens (A), Croton monanthogynus (B). Uniseriate uni-glandular hairs on Zollikoferia niidicaulis (C), Silene villosa (E), Geranium favosum (K), Boerhaavia repens (M). Glandular hairs with two-celled heads on Hesperis gliilinosa (D), Pilyrodia salvifolia (F), Cyclamen persicum (H), Lysimachia Nummularia (J), Chenopodium Botrys (L), Diospyros Kaki (O). Glandular hairs with four-celled heads on Humulus Lupulus (G), Boswellia papyrifera (V), Humulus Lupulus (Y). Glandular hairs with five-celled heads on Combret'um aculeatum (Z), Humulus Lupulus (Y). Glandular hairs with six-celled heads on Rhododendron Dalhoiisia (X), hair characteristic on the Phaseolece (U). Glandular hairs with eight-celled heads on Lavandula vera (W). Glandular hairs with multicellular heads on Pieris ftoribunda (N), Begonia carolinicBfolia (S), Begonia pretoniensis (s). Glandular hairs with four and eight cells respectively on Picramnia coccinea (P). Glandular hairs with two and four cells re- spectively on Cistus ladaniferus (R). Double glandular hair on Rhodoaendron lanatum (T) — Adapted from Solereder and redrawn by Hogstad. CELL-CONTENTS AND FORMS OF CELLS. 283 goniaceae, Berberidaceae, Bixaceae, Borraginace^, Burseraces. Capparidacese, Capnfoliaceae, Caryopyhllaceae, Chenopodiaceae, Combretaceae, Compositae, Convolvulaceae, Cornacese, Crassulaceae, Cruciferae, Cucurbitaceae, Dipsaceae, Ericaceae, Euphorbiace^, Fagaceas, Geraniaceae, Hippocastanaceae, Hydrophyllaceae, Labi- atae, Leguminosae, Malvaceae, Melastomataceae, Meliaceae, Meni- spermaceae, Moraceae, Myrsinaceae, Nolanaceae, Nyctaginaceae, Nymphaeaceae, Piperaceas, Platanaceae, Plantaginaceae, Polemoni- aceae, Polygonaceae, Portulacaceae, Primulaceae, Rosaceae, Ru- taceae, Sapindaceae, Saxifragaceae, Scrophulariaceae, Simarubace^, Solanaceae, Sterculiaceae, Theaceae, Tiliaceae, Umbelliferae, Ul- maceae, and Valerianaceae. 3. Glandular leaf-teeth, as the name would signify, include the glandular hairs formed on the lobes of leaves. They vary in structure and may secrete mucilage, as in the Violaceae (Fig. 120) and in some of the Compositae, or they may secrete, in addi- tion, resin, as in the Rosaceae, or calcium oxalate, as in the Saxifragaceae. 4. Special forms of multicellular glands are found in the Aceraceae, in which a pair of glands are fused together. In some of the Compositae and Moraceae a group of glandular hairs are united. Other special types also occur in the Droseraceae, Ana- cardiaceae, Leguminosae, etc. 5. Hair-like external glands having a complicated structure have been observed in a number of families. They are limited to certain portions of the plant, being found in the Apocynaceae at the base of the leaves and in the Rubiaceae only on the stipules. They are usually very large, secreting considerable mucilage and resin. The glandular, shaggy hairs occurring on the stipules in the Rubiaceae are of this type, the secretion being often so abundant that the young leaves emerging from the stipular sheath are coated with this resin, which is even retained by the mature leaves. IL NoN-GLANDULAR Hairs are of three general types: i. Simple hairs (Figs. 148, 151), which may be unicellular or uni- seriate, — i.e., consisting of a series of superimposed cells. 2. Peltate or stellate groups (Fig. 153, D, E, H, K), consisting of two or more hairs united at the base and spreading like a star. 2S4 A TEXT-BOOK OF BOTANY. Fig. 150. Forms of glandular hairs: A, corkscrew-like hairs from the inner surface of the spurred corolla of lavender; B, longitudinal section of rhizome of Dryupteris mar- ginaLis showing large intercellular space and an internal oil-secretion hair; C, hairs from stramonium feaf; D, hairs from Digitalis; E, hair from sage; F, hair from eriodictyon; G hairs from inner walls of pericarp of vanilla; H, hair from cannabis indica; I, hairs from surface of fruit of Rhus glabra; K, hairs from belladonna leaf. CELL-CONTENTS AND FORMS OF CELLS. 285 These may consist of one or more series of cells, separated bv a columnar cell. 3. Shaggy hairs ( 1< ig. 153, G). in which the epidermal layer of the column of cells is modified to papillae Fig. 151. Forms of non-Rlandular hairs: A, hair from the epidermis of strophanthus; B, a hail trom the capsule of Mallotus philippinensis (found in the drug known as kamala); C, hairs from the leaves and bracts of cannabis indica, two of them containing cystoliths of calcium carbonate; D, a hair from the under surface of the leaf of senna; E, hairs from leaf of digitalis; F, two forms of hairs from sage leaf; G, two forms of hairs from the leaves of wormwood {Artemisia Absinthium): a T-shaped non-glandular hair and a short glandular hair. which are directed upwards, giving the surface of the plant the appearance of being covered with rough hairs or wool. Non-glandular hairs occur on a large number of plants. They 286 A TEXT-BOOK OF BOTANY. vary in form and are very characteristic in a great many plants. The terms used to describe the various types of hairs are in a few instances rather simple, but there are so many modifications that nothing short of an illustration will suffice to define them. The simple hairs may be divided into a number of sub-divisions: (a) Papillose hairs, being short outgrowths of the epidermal cells, somewhat resembling the papillae found on the ventral surfaces of petals. This form is found in a relatively few families, (b) Unicellular hairs, being outgrowths considerably longer than papillae and occur in a large number of plants. This is also true of a third type (c), known as uniseriate hairs and in which there Fig. 152. Forms of non-glandular hairs: A, twisted hairs from under surface of leaf of eriodictyon; B, lignified hairs from the epidermis of nux vomica; C, branching hairs from the leaf of mullein (I'crbasciitn Tliaj^sus). are two or more cells connected as in a chain. Among special terms frequently used the following may be mentioned: (of) Hooked hairs (Fig. 154, A, B), in which the summit is bent in the form of a hook, {e) Two-armed hairs (Fig. 153, D), in which the summit consists of two cells which diverge from each other and spread out horizontally or parallel to the surface of the leaf. (/) Stellate hairs (Fig. 151, B) consist of a group of cells ar- ranged around a simple point, as in the Cruciferae and Saxifra- gaceae. {g) Peltate hairs (Fig. 153, E) consist of a group of radially arranged cells, of which all or only some reach the centre of the shield, as in the Solanaceae, Malvaceae, Loganiaceae, and CELL-CONTENTS AND FORMS OF CELLS. 287 Rosaceae. (h) Candelabra or abietiform hairs (Fig. 153, L) are those which have a uniseriate main axis, interrupted at intervals by whorls of ray cells. These show considerable variation .and are very characteristic in the Solanaceae, Acanthaceae, Leguminosse, Labiatae, and Euphorbiaceae. (/) Stinging hairs (Fig. 153, /), or those containing an irritating substance, as in the stinging nettle and other plants of the Urticaceae. The hairs are rather long, the Fig. 153. Several types of non-glandular hairs. Crystal hairs on Malanea macro- phylla: A, showing hair with a single row of crystals; B, cell with 2 rows of crystals; C, transverse section of B, showing crystals. Two-armed hairs on Artemisia Absinthium (D) and Dichondra repens (H) ; F, uniseriate non-glandular hair on Pongamia glabra; E. longi- tudinal view showing two of the cells of a peltate hair on Solatium argenteum; G. shaggy hair on Calandrinia umbellata; J, upper portion of stinging hairs of LXica rfiojca; K. cup- shaped peltate hair on Rhododendron A nthopogon; L, candelabra hair on \'erbascum Thap- sus. — Adapted from Solereder and redrawn by Hogstad. summit bearing a spherical or ovoid head, which is obliquely in- serted and rather easily detached, thus leading to the emission of the contents. The stinging sensation was formerly stated to be due to formic acid, but it is now supposed to be in the nature of a substance related to the ferments. (/) Crystal-containing hairs. Calcium oxalate (Fig. 153, A, B, C), either in the form of rosette aggregates or prisms or needles, is sometimes present in the 288 A TEXT-BOOK OF BOTANY. Fig. 154. Hairs in the Compositae: A, slightly curved or hooked hairs on the corolla of Dandelion; B, hooked hairs on the filaments of Inula; C. hairs on pappus of Tragopogon pratensis; D, hair from akene of Tragopogon pratensis; E, portion of barbed hair upon pappus of Inula; F and G, double hairs from achene of Tagetes tenuifolia; H, double hairs from achene of Inula; J, double hair from corolla of Calendula, CELL-CONTENTS AND FORMS OF CELLS. 28Q Fig. 155. Characteristic branching hairs found on the stem. leaves, and calyx of Hyoscyamus muticus. Stinging hairs of some of the Euphorbiaceae, as well as in some of the genera of the Cornaceae, Geraniaceae, Rosaceje, and Saxi- fragacese. 19 290 A TEXT-BOOK OF BOTANY. LiGNiFiED Hairs. — In some seeds, as in nux vomica, the hairs are strongly lignified, as are also the bases of the hairs of Stro- phantus hispidus. This is due to a lignocellulose modification of the wall, and, since broken hairs look more or less like fibers, one might easily be led astray in the study of powdered drugs. It is not usual to make a microchemical study of the walls of non- glandular hairs, but this subject is well worthy the attention of investigators. False Plant Hairs. — While it is impossible for the careful student of plant morphology to mistake anything else for plant hairs, it is, nevertheless, v/orth while to call attention to some of the mistakes that are liable to be made. In works on systematic botany sometimes occur contradictory statements concerning the abundance or scarcity of hairs, especially as they relate to the flower. In a superficial examination, for instance, in the violets, large masses of germinating pollen grains with their tubes matted together are not at all uncommon in the throat of the corolla, and these have been mistaken for hairs. Furthermore, the mycelia of fungi may be mistaken for hairs, especially in young seedlings, as of hyoscyamus, belladonna, etc., where thread-like delicate branching hairs may occur. In the examination of economic prod- ucts, especially powdered drugs and spices, mistakes of this kind may occur, unless the student has devoted some attention to this study. In all studies of plant hairs the student should carefully locate the summits and bases, and unless these can be recognized, or if broken made to correspond to each other, one cannot say that hairs are present. Cork Cells replace the epidermal cells of roots and stems that persist year after year. They are formed, as has already been stated, from a distinct meristem, called the phellogen. Cork cells differ from the epidermal cells in that the walls are uniformly thickened and on surface view are polygonal in shape. The walls consist of suberin, a substance allied to cutin ; in some instances they also contan lignocellulose, forming cork stone-cells, as in asclepias and calumba. The young cells may contain a thin layer of cytoplasm and a nucleus ; they usually also contain brownish masses of tannin or tannin-like compounds, and occasionally crys- tals of cerin or calcium oxalate. CELL-CONTENTS AND FORMS OF CELLS. 291 Cork not only occurs as a secondary protective layer, but may also arise in other parts of the plant as a result of injury, as in leaves, fruits, stems, and tubers. It also arises as a result of the disarticulation of the leaf in autumn. Periderm. — The epidermis is not adapted for the protection of the perennial plant organs on account of its thin, frequently delicate structure and its inability to continue with the increase in thickness of stems and roots. Hence it becomes replaced by the periderm, which consists of a lasting tissue, the cork, and of a meristematic tissue, the phellogen, which reproduces the cork when it becomes torn or destroyed, by the continued growth in Fig. 156. Section through a secondary lenticel in the bark of Sassafras; e, epidermis. st, stone cells; phel, phelloderm derived from secondary phellogen and having thick ligni. tied wall; p, parenchyma; c, cork; com, complementary cells. — After Weiss. thickness of stems or roots. Cork is not only of sub-epidermal origin, but may occur deeper in the cortex (Fig. 158), or even in- side the endodermis. In the latter case, as in roots, it owes its existence to the activity of the pericambium. Superficial, i.e., hypodermal cork, is extremely rare in roots. Not infrequently a layer of cells is formed inside of the phellogen, being fermed the phelloderm. They usually contain plastids ; the walls are moder- ately thick and free from intercellular spaces (Fig. 156). Lenticels may be described as biconvex fissures in the periderm which permit of the easy access of air to the intercellular spaces of the rather loosely arranged cells lying beneath them (Fig. 292 A TEXT-BOOK OF BOTANY. 156). They usually arise as the product of a meristem situated beneath the stomata of the epidermis, the stomata being replaced by them when cork is developed. Several types of lenticels are 1 ^^- i^^HI ^B ■ ' ^^W^P^-- -f^ "^- • ■ i^H 1 / -f V, ;--'^^^^^K|fe!^B Fig. 157. Bark of Rliamnus Pursliianus showing large whitish patches of lichens, and numerous lens-shaped lenticels. distinguished. They are quite characteristic and prominent in a number of barks, as those of species of Betula, Prunus, Rham- nus (Fig. 157), etc. CELL-CONTENTS AND FORMS OF CELLS. 293 -r, o T^ 1 ^^„f r.( rnrlf A in eoidermal cells of stem of Oleander; B, cork cells.— After Dippel in "Das Mikroskop.' BoRK —The cork cambium or phellogen develops before ma- turity in the green stems of woody plants belonging to the dico- tyledons. It mav develop in the primary or secondary tissues 294 A TEXT-BOOK OF BOTANY. (Fig. 158). When the phellogen develops in the deep-seated tissues, the cells outside of the corky layer sooner or later die and slough off. This is due to the fact that the cork cells are suberized and do not permit the passage of the cell-sap containing food sub- stances. In large shrubs and trees with thick stems and trunks A B Bf JK A A^sm^ ^"^ p Fig. 159- Development of Bork: A, in bark of cherry (Prunus Cerasus), showing a layer of periderm (k) with thin-walled eork cells; bast fibers (Bf); parenchyma (p) ; stone cells (st) occasionally branching and lengthened into fibers. B, inner layer of periderm of Quercus Robiir, showing compactly arranged, thick-walled cork cells (P) filled with a reddish phlobaphene or altered tannin; starch-bearing parenchyma (p) ; stone cells (st) ; sieve tubes (Bg) ; bast fibers (Bf) ; prism of calcium oxalate (kr) ; several rows of thick- walled, porous cells (x). — After Dippel in "Das Mikroskop." a number of successive layers of cork or periderm are formed. These layers with the dead cortical tissues between them persist to some extent and constitute what is known as bork, i.e., bork consists of a number of alternate layers of periderm and cortical CELL-CONTENTS AND FORMS OF CELLS. 295 tissues. The cork cells in different trees are variously (lcvcloi)ed and accordingly two types of bork formation may be distinf2:uishcd. In sycamore, cherry and plum trees the cork cells are only slif^^htly thickened (Fig. 159) and the periderm in the form of layers Fig. 160. White oak bark with the fissured corky layers (bork). separates from the tree annually. In the oaks, chestnuts and tulip poplar the cork cells (Fig. 159) are thick walled and com- pactly arranged so that, under the stress of growth and thickness of the bark, the layers of periderm are split longitudinally, giving 296 A TEXT-BOOK OF BOTANY. rise to the deep furrows (Fig. 160) which are so characteristic of the outer surface of our large trees. Laticiferous or milk tissue occurs in all those plants which emit a milk- juice on being cut or otherwise wounded. The juice may be colorless, as in the oleander; whitish, as in the x\sclepia- daceae, Apocynacese, etc. ; or yellowish, as in the Papaveraceae. It contains caoutchouc, oils, resins, mucilage, starch, calcium oxalate and alkaloids as well. The walls are relatively thin and consist chiefly of cellulose. The tissue consists either of single cells of definite length, as in the Papaveraceae, or the cells may be of indefinite length, as in the Asclepiadaceae, or it may consist of a more or less branching network (Fig. 127) formed by the anastomosing of a number of cells, as in Taraxacum (consult paragraph on Latex, pp. 238-241). As has already been stated, the latex of plants contains a num- ber of plastic or trophic substances, — i.e., those which, either at once or after being stored for a time as reserve food, are drawn into metabolism and serve as nutrient material. They also con- tain a number of aplastic or non-trophic substances, as caoutchouc, resin, alkaloids, volatile oils and tannin, which are in the nature of metabolic by-products and are incapable of further metabolism. While it is highly probable that the laticiferous tissue, on account of its being always associated with the phloem, functions to some extent for the transportation of plastic substances, yet it serves another purpose, viz., to protect the underlying cells after injury of the plant by insects or herbivorous animals. This protection results from the rapid coagulation of the exuding latex upon exposure to the air and forming a varnish-like surface. In some cases the latex contains a poisonous principle which exercises a protective function. In Rhus Toxicodendron the principle causing the eczema, namely toxicodendrol, is supposed to be formed in laticiferous tissues being transferred to the hairs, which upon being broken liberate the poison. CELL-CONTENTS AND FORMS OF CELLS. 297 2.^ 1:? o 01 c O 3« 5 2-a> o Cm 0) * a? o3 ,— o n> o — 5^3 o C p en t3 h3 3?3 5'3 ^ 3 o r>'^ TO ."^ ,5 St O r+ "^ O -I s-w o O n> 3 5' 1/1 o a. « rti _ 3^^ E^ S « g ^-n. o-p 3 §■< fit 5 o p p -.3 ^ 3 0) m • CL^ P « o O 3. rti •< PI „35^ «. p crp o ^ f?rl •S.3 -0° 3 2 CLt) ■^^> en Cl. B -I (T> Q. s-8 3 "> (D m = 3-9 "> TO fO If 3 o "> 'p S e3 ^ p ": f « o O 3S5 "S-zi 3;,; M O ■— "-I O o 3 =:£•" hH en p p o 3 P O " 2 ^S •OoO OP"i^^ 3 c 5 3._P o 3 p "" a. o 3 rD ^3 c+ O p w :;.*o o fl> O en p f i/i O St 3^5 p o< *d ^ o 3:^3 o o 3. O —3 3 -TO ^ - " -^ '35 en O pSI ft. —H M -1 p 3* r+^ £-2 Go 5-5^2 2.0-^ en fB 7 ^. Sr ^ r! ^ o- TO 2 9 p c 5^B 3' q ^'3'3 ^22.? 3' w o 5^ ■^ o 2.P' " ^^C O f» O ^ 3 3 c 2 o 5 <-* f^ p '^ en _ Si CHAPTER III THE OUTER AND INNER MORPHOLOGY OF HIGHER PLANTS. INTRODUCTORY. It may be well to repeat at this point that on germination of the megaspore the female gametophyte bearing the egg-cell is formed, and that on germination of a microspore the male gameto- phyte bearing male nuclei is organized. The union of egg-cell and a male nucleus gives rise to the sporophyte embryo contained in the seed, which develops into the plant we see, namely, the sporophyte. The female gametophyte always remains concealed within the embryo-sac, and the male gametophyte may be said to embody the protoplasmic contents of the pollen tube. A complete flower is made up of floral leaves and sporophylls, the latter being essential for the reason that they give rise to the spores. While the flower belongs to the sporophyte generation, the propagative organs may be said to be derived from both the sporophyte and gametophyte, and hence may be distinguished as asexual and sexual. The following outline illustrates their derivation : Egg-apparatus, containing egg-cell or female gamete ]\Iale Generative-cell, giving rise to male nuclei or male gametes Microsporangium (pollen sacs) giving rise to microspores (pollen grains) ]\Iegasporangium (nucel- lus) giving rise to mega- 2^8 ^ spore (embryo-sac) Sexual, derived from gametophytes (sex- ual generation) Propagative Organs Asexual, derived from sporophyte (asex- ual generation) MORPHOLOGY OF HIGHER PLANTS. 299 The vegetative organs comprise the root and shoot, the latter heing usually dilTferentiated into shoot axis or stem, and leaves. The usual type of shoot is one which bears leaves and is exjiosed to the light. The work of carbon dioxide assimilation (photosyn- thesis) being carried on for the most part by the leaves, the axis is sometimes spoken of as the " assimilation shoot." B Fig. 161. A, advanced stage of germination of the common garden pea (Pt'sum sa- tivum) showing growing point of root protected by root-cap (p); root branches or second- ary roots (rb); hypocotyl (he); epicotyl or stem above the cotyledons (ec) ; cotyledons (one in view) (c). B, plantlet of white or yellow mustard (Stnaf^is alba) showing copious development of root-hairs (h). L OUTER MORPHOLOGY OF THE ROOT. The Root^ or descending axis of the plant, normally pene- trates the soil, absorbing inorganic substances in solution and act- ing as an anchor and support for the shoot. True roots are found only among plants having a vascular system, as the Spermophytes and the higher Pteridophytes, although, on the other hand, some of the higher plants do not possess them, as certain of the sapro- phytic orchids and some of the aquatic plants as Utricularia. 300 A TEXT-BOOK OF BOTANY. Lemna, etc. If we take a germinating plant and mark the root into ten equal divisions, beginning at the apex, and place the plant in a moist chamber, it will be found in the course of one or two days that the marks between i and 5 have become much Fig. 162. Longitudinal section through the tip of the root of Indian com (Zea Mays) showing root-cap: a, outer layer; i, inner layer. — After Sachs. farther apart, and that the growth in this region is about three times that between 5 and 10. This experiment indicates that the growth of the root takes place at or near the apex, this region being known as the point of growth, or point of vegetation (Fig. 162). MORPHOLOGY OF HIGHER PLAXTS. 301 Upon examining the tip of a very young root by means of the microscope, it will be seen that the growing point is protected by a cup-shaped body of a more or less solid structure and frequently mucilaginous; this is known as a root-cap. Its function is to protect the growing point, and it exists in all roots of terrestrial, epiphytic, and aquatic plants except the parasites. Just above the root-cap there is developed a narrow zone of delicate hairs, which arise from the surface cells and are usually thin-walled and unicellular. These are known as root-iiairs (Fig. 161, B) and their function is twofold: (i) They secrete an acid which renders the inorganic substances of the earth soluble, and (2) they absorb these and other substances for the nourish- ment of the plant. It should be stated that there are a number of plants which for various reasons do not possess root-hairs, such as water-plants, marsh-plants, certain Coniferae, Ericaceae, etc. When the primary root persists (as in Gymnosperms and Dicotyledons) it increases considerably in length and becomes ramified ; if, at the same time, it increases in thickness, and much more so than its branches, then it is called a tap-root (as in carrot, beet, etc.). In the vascular cryptogams (Pteridophytes) and the monocoty- ledons the primary root is generally thin and weak, frequently but little ramified, and disappears at an early stage, being re- placed by SECONDARY ROOTS^ as in Zea. Secondary roots may arise not only upon the stem but even upon leaves, as in Begonia and Bryophyllum. The term lateral roots is restricted to those that develop from the root alone. The development of roots upon shoots or of so-called '* ad- ventitious roots'" occurs in nearly all of the woody plants of the Spermophyta. Many annual herbaceous plants do not possess this capacity at all. The adventitious roots arise from " root- primordia " which are formed under the cortex of the shoots. While ordinarily they do not develop upon the shoots, yet if cuttings are made, as of Coleus, Geranium, Rosa, etc., we find " either singly or on both sides of the axillary buds " the develop- ment of adventitious roots from the latent root-primordia. Influence of Gravity. — The root is popularly supposed to grow downward, in order to avoid the light. On the other hand, 302 A TEXT-BOOK OF BOTANY. the theory has been established (as a result of Knight's experi- ments) that the root grows downward by reason of the influence of gravity. In addition it may be said that the principal functions of the root, namely, those of absorbing inorganic food materials and of fixing the plant to the soil, determine in a measure the direction of its growth. The tendency of the root to grow down- ward is a characteristic which distinguishes it from other parts of the plant, and it is said to be positively geotropic (Fig. 163, A). Fig. 163. A, seedling of Brassica nigra in which root and stem have curved into a vertical position after being Icid horizontally. B, seedling of Sinapis alba, the hypocotyl showing a positive, the root in water a negative heliotropic curvature. The arrows show the direction of the incident rays of light. — After Pfeffer. The influence which gravity has on plants may be best under- stood by bearing in mind that gravity is a constant force which acts perpendicularly to the surface of the earth, and that all parts of the plant are subject to its influence. The organs of plants respond in dift'erent ways to the action of gravity, but a clear distinction should be made between mere mass attraction, or that manifestation of the force of gravity whereby the heavily laden branch of a fruit tree bends downward, and the stimulus which causes the primary root of a plant to grozv downward and the shoot to grow upward. While all parts of the plant are subject to the influence of gravity, not all the organs of plants respond in an equal degree. This is well illustrated by roots themselves. MORPHOLOGY OF HIGHER PLANTS. 303 It is well known that, whatever the position of the seed at the time of germination, the young radicle begins to grow perpen- dicularly downward ( Fig. 163, A ) . The branches, however, which arise on the primary root are less positively geotropic and, instead of growing downward parallel with the primary or tap root, di- verge at an angle from it (Fig. 161 ). The secondary branches are still less affected by gravity and diverge still more from tlie per- pendicular, or grow out horizontally, while still others do not Fig. 164. Over-turned tree trunk showing spreading root-system, the main or tap root having died away appear to be in the least affected by gravity and grow freely in any direction. In the case of large trees we frequently find that the lateral roots spread out in a more or less horizontal plane near the surface of the earth, and if the main root has died the influence of gravity is not very evident (Fig. 164). But here it must be re- membered that gravity was instrumental in determining the direc- tion of growth at an earlier stage. This spreading of the roots near the surface of the earth is of decided advantage to plants, for it enables them to avail themselves of the better soil of the surface 304 A TEXT-BOOK OF BOTANY. layers. As indicated, gravity also determines the upward perpen- dicular direction of the shoot, which is therefore said to be NEGATIVELY GEOTROPic, but, as in the case of the root, the branches are less influenced by it and hence diverge at various angles from the main axis. Some of the other efifects of gravity may be noted. If the end of a shoot be cut off, the branches next to the top will grow per- FiG, 165. Mangrove forest {Rhizophora Mangle), showing the habit of growth, es- pecially the numerous aerial roots which form an almost impenetrable thicket. The man- grove is common along the southern shores of Florida, in the Bahama Islands, and in the West Indies. Many shellfish, lobsters, and other forms of sea life are often found clinging or attached far up on the roots where they become lodged during high tides.— Photograph from article by Henry Trimble on Mangrove Tannin in Contributions from the Botanical Laboratory of the University of Pennsylvania, 1892, p. 50. pendicularly upward and thus assume the work of the main axis. Likewise in the case of roots, if the apex of the main or tap root be cut off, the branches near the end will assume a perpendicular direction. It will frequently be noticed in the case of trees which have been uprooted or where branches have been bent over hori- zontally that the new branches which arise grow perpendicularly upward. Creeping shoots furnish another good example showing MORPHOLOGY OF HIGHER PLANTS. 305 Fig. 166. Tuberous root of Ginseng (Panax quinquefolium). The root on the left is a fresh specimen and was grown in the United States. The one to the right was purchased at a Chinese bazaar. It is translucent, of a yellowish-brown color, and has the characteristic shape and markings considered desirable by the Chinese. The markings on the upper segment of the specimen are stem scars which are usually found on old roots. The trans- lucent appearance is no doubt due to the manner of treatment. While the method is not generally known, similar specimens may be prepared by treating the recently gathered roots with freshly slaked lime. the influence of gravity, the branches growing- upward and tlic roots downward. The root exerts a certain amount of upward jircssurc on tlic liquids in the stem. This fact can be demonstrated by cutting oil 20 3o6 A TEXT-BOOK OF BOTANY. the stem just above the surface of the earth and attaching thereto a glass tube by means of a tightly-fitting rubber tube. It is de- sirable to perform this part of the operation under water and to have the glass tube partly filled with water at the beginning of the experiment. This is done to prevent the clogging up of the vessels with air, which prevents the ready passage of fluids through them. If the root is now kept moist, the osmotic pressure of its cells forces water up into the glass tube, sometimes to a height of several feet. Experiments on the begonia and on many other plants succeed very well, but for some reason the geranium is impracticable to work with. The manometer devised by Ganong, while not showing the quantity of water forced up by the root, shows the amount of pressure exerted, which is really the most important fact to be ascertained. Modified Roots. — Roots which arise from the nodes of the stem or other parts of the plant are known as secondary or adventi- tious roots. These include the aerial roots of the banyan tree and the Mangrove (Fig. 165), which are for the purpose of sup- port ; the roots of the ivy, which are both for support and climb- ing, and the roots of Indian corn and many palms which serve both for support and the absorption of nourishment. Under this head may also be included the aerial roots of orchids and the root-like structures, or haustoria, of parasites, as of mistletoe and dodder, which penetrate the tissues of their host plants and whose vascular strands come into most intimate relations with those of hosts. Of special interest also are the breathing roots of certain marsh-plants Vv^hich serve to convey oxygen to the submerged parts ; and the assimilation roots of certain water-plants and epiphytes, which are unique in that they produce chlorophyll. In certain plants the roots give rise to adventitious shoots, as in Prunus, Rubus, Ailanthus, etc., and in this way these plants some- times form small groves. Root Tubercles. — The roots of the plants belonging to the LeguminoscT are characterized by the production of tubercles, nodules or swellings (Fig. 167) which have been shown to have a direct relation to the assimilation of nitrogen by the plants of this family. Like carbon, nitrogen is one of the elements essential to plant-life, being one of the constituents of protoplasm and MORPHOLOGY OF HIGHER PLANTS. 2^^^? present in various nitrogenous (protein) compounds which occur as normal constituents of the plant. The nitrogen required by plants is derived either from nitrogen salts contained in the soil, as nitrates and ammonium salts, or from the free nitrogen of the atmosphere. While most of the higher plants are able to assimilate nitrogen compounds existing in the soil, only the Leguminosae and Aristolochiacese, with possibly a few exceptions, are able to assimilate atmospheric nitrogen, and in this respect the Fig. 167. Root tubercles on Lupinus, one of the Leguminosce: A, roots with tubercles; B, transverse section of root showing the cells (b) which contain the nitrogen bacteria.— A. after Taubert; B. after Frank. majority of the Leguminosae stand as a class by themselves. Apparently in direct relation to this character stands the fact that the seeds of these plants contain a high percentage of nitrogen. This special ability of the Leguminosae to fix atmospheric nitrogen in the plants depends upon the presence of the nodules, wdiich are due to the infection of the roots by a soil-bacterium {Psciidoniouas radicicola), although the precise mode of fixing the nitrogen is 3o8 A TEXT-BOOK OF BOTANY. not known. The bacteria seem to be localized in the nodules and are not found in any other part of the plant. It has been shown that when the roots of leguminous plants are free from nodules they do not have the power of assimilating free nitrogen. On the other hand, when the nodules produced by the bacteria are developed, the plants will grow in soil practically free from nitrogen salts. Because of this power the plants of this family are useful in restoring worn-out land, i.e., land in which Fig. i68. Transverse section of a root bearing root hairs; the latter are thin walled, irregularly bent, and attached at various places to small particles of soil. The hairs secrete an acid, rendering the inorganic substances soluble, which are then diffused through the walls of the hairs, transmitted to the cortical parenchyma and distributed through the conducting cells of the xylera to the shoot. — After Frank. the supply of nitrogen is exhausted, and they thus play an impor- tant role in agricultural pursuits. The enriching of the soil is accomplished by ploughing under the leguminous crops, as of clover or alfalfa, or allowing the nodule-producing roots to decay, when the nitrogen compounds are distributed in the soil. (Consult Bulletins on " Soil Inoculation for Legumes," issued by the Bureau of Plant Industry, U. S. Department of Agri- culture.) MORPHOLOGY OF HIGHER PLANTS. 309 THE INNER STRUCTURE OF THE ROOT. Primary Structure. — If wc make a transverse section of the young portion of a root (Vascular Cryptogam, (iymnosperm, or Phenogam), we notice the following tissues ( h'igs. irxj-174). The outermost tissue is epidermis (E), it heing generally thin- walled and destitute of cuticle ; it is, as a rule, hairy, and these hairs, which are relatively long, but always unicellular, are known as ROOT-HAIRS (Figs. 161, 168) ; they ramify but very seldom. Inside the epidermis there is frequently present a iiypodermis 'VQM Fig. 169. Radial vascular bundle in root of Allium ascalonicum, showing a larg'. central trachea from which radiate five small groups of tracheae and between which are th. groups of leptome or sieve; p, layer of pericambium or pericycle; d, transition cells ur pas- sage cells in the endodermal layer, and which permit the easy transfer of substances between the cortical parenchyma and the tracheae of the stele.— After Haberlandt. (sometimes referred to as an exodermis) composed of a single layer of cells or, at the most, of but several layers, the cells of which differ in shape and size from those of the epidermis and the adjoining cortical parenchyma. The hypodermis takes the place of the epidermis when the latter is worn off, except in the few cases where hypodermal cork becomes developed, as in Cephalanthus, Solidago, and in the Bignoniacese. The root bark is composed of parenchymatous cells, being 3IO A TEXT-BOOK OF BOTANY. commonly referred to as the cortex, and is either homogeneous or divided into two zones, the outer or peripheral being composed of thick-walled cells which naturally belong to the hypodermis and an inner or internal strata made up of thin-walled cells. The cells of the cortical parenchyma may contain starch, calcium oxalate, calcium carbonate, and there may be associated with them Fig. 170. Cross-section of the primary root of a germinating plant of Phaseolus muUiflorus, showing development of secondary structures: p, group of primary vessels; g, larger tracheae of secondary development formed between the four primary strands of xylem; b, the four groups of phloem alternating with the four initial groups of xylem and beneath which secondary tracheas are forming (g') ; pc, pericambium (pericycle), a layer of cells beneath the endodermis (s). A few layers of cortical parenchyma are shown outside of the endodermis. In the middle is a well-developed pith (M) which sometimes is developed in roots. — After Sachs. secretory cells or receptacles. Immediately beneath the innermost layer of cortical parenchyma is a distinct layer of cells usually considered part of the cortex and knowm as the endodermis. It consists always of a single layer of cells, without any intercellular spaces, and the radial walls show in transverse section Casparyan spots,^ depending upon a local folding of the cell-wall, which is here suberized. In the course of time the cell-walls of the en- ^ " Physiologische Pflanzenanatomie," by Dr. G. Haberlandt, p. 245. MORPHOLOGY OF HIGHER PLANTS. 311 dodermis frequently become thickened, either all around, or only on the inner or radial walls, so that we might speak of an O- endodermis as in Honduras sarsaparilla or an L^-endoderniis as in Mexican sarsaparilla, according to the manner of thickening. Fig. 171. Cimicifuga. Transverse section of the central part of a mature root in which the secondary changes are completed: a. parenchyma of primary cortex; b endo- dermis; c, cambium zone; d, tracheae in secondary xylem; e. broad, wedge-shaped medullary ray; f, outer portion of one of the primary xylem bundles; g. pericycle-parenchyma beneath the endodermis; h, inter-fascicular cambium.— After Bastin. This is especially the case in the monocotyledons where the walls of the endodermal cells become completely suberized and im- permeable to water. In some roots the cells of the endodermis may be uniformly thick-walled throughout, while in others some 312 A TEXT-BOOK OF BOTANY. of the cells may remain thin-walled, and these cells, the so-called *' transition cells " or " passage cells," form channels of com- munication between the cortical parenchyma and the vessels of the stele (Fig. 169) ; they are therefore located just outside the peripheral vessels of each ray of the xylem (or hadrome). Inside the endodermis is the stele, formerly called the central- cylinder. In this the peripheral stratum, sometimes composed of two or three layers of cells, represents the pertcambtuai (or pericycle). The cells are generally thin-walled, and in Dicotyle- dons and Gymnosperms are able by cell-division to form cork and Fig. 172, A transverse section through the root of a germinating pea-plant (Pisum') about 40 mm. from the tip, showing the origin of a root-branch (RB); E, epidermis; C, pri- mary cortex; X, hadrome (vessels); P, leptome (sieve); EN, endodermis. secondary cortex, but in all vascular plants it is capable of givmg rise to "lateral branches" or "lateral roots" (Figs. 161, 172), hence it is frequently referred to as the " rhizoc.enol'S layer." Inside the pericambium (by some authors compared with the pericycle of the stem) we tind strands of phloem (or leptome) (P) alternating radially with a corresponding number of strands of xylem (or hadrome) (X). The number of these strands vary in the different groups of plants (Figs. 169-174), being highest in the monocotyledons wdiere a pith is developed, as in sarsaparilla, several grasses, palms, etc. This peculiar arrangement of the Morphology of higher plants. 313 phloem and xylem, as separate strands alternating with each otiier and not being located, as in stems, in the same radii, has given rise to several adverse views. Some authors have considered the root-stele as one single mestome-strand (or fibrovasculaf strand), while others, especially of recent date, consider it to be composed of several mestome strands. The xylem or hadrome contains tracheae or vessels, the perij^h- eral being spiral and narrower than the inner, which are scalari = form or reticulate. The tissue in the center of the stele in mono- cotyledons is not uncommonly made up of parenchyma cells, and Fig. 173. Primary structure in the root. Transverse section ot root of pea (Pisum) about 40 mm. from the root-cap: H, epidermal cells, some of which are developed into root -hairs; C, primary cortex; EN, endodermis; PC, pericambium; X, hadrome, composed of tracheae; P, leptome, composed of sieve cells, the hadrome .(vessels) and leptome (sieve) forming a triarch radial fibrovascular bundle. corresponds exactly with the pith of the stem. In roots it is often called CONJUNCTIVE tissue, and the cells may contain starch and crystals of calcium oxalate. Secondary Structure. — In roots that are able to increase in thickness (as in Gymiiosperms and Dicotyledons), the increase depends upon the activity in the pericambium, some of the cells becoming merlstematic. These meristematic cells are known as phellogen, developing cork outwardly and secondary cortex in- wardly. The meristem of the stele or cambium also becomes very active and develops on the inner face of the phloem and extends 314 A TEXT-BOOK OF BOTANY. from there to the outside of the peripheral vessels of the xylem (Fig. 174) ; thus a continuous cambial zone gradually arises. From this zone secondary tracheae or vessels become developed on the inner face of the primary phloem, while secondary phloem becomes differentiated outside the primary rays of xylem ; or only parenchyma develop's outside the primary xylem, resulting in Fig. 174. Section in the older part, higher up on the root of pea (Pisum), showing in addition to what has been observed in Fig. 173, the beginning of the change from primary to secondary structure: CA, the development of a cambium; SX, secondary hadrome (or vessels), and SP, secondary leptome (or sieve). the formation of secondary parenchyma-rays (or medullary rays). In other words, the original radial structure of the stele changes to the collateral type (Fig. 175). Owing to this increase within the stele, the peripheral tissues from the endodermis to the epidermis naturally become broken and are subsequently thrown off, but are replaced by the pericambial cork and secondary cor- tex derived from the pericambium. The older roots, then, of Gymnosperms and Dicotyledons thus resemble the structure of stems, except that no pith exists in these roots, at least not usually. MORPHOLOGY OF HIGHER PLANTS, 315 Some differences are, however, quite noticeable in some instances, as in the thick roots of Beta, Radish, etc., where the wood parcn- ^^ - E -M Fig. 175, Fully developed secondary structure in root. Transverse section of root of pea (Pisum) at the end of the summer's growth: E, some epidermal cells with fragments of root-hairs; C, primary cortex; EN, endodermis; K, pericambial cork; B, bast fibers; SC, secondary cortex; S, sieve; T, tracheae; W, wood fibers; WP, wood parenchyma; M, medullary rays; the tracheae (or vessels) and leptome (or sieve) forming open collateral fibrovascular bundles, these being found in dicotyledons with but few exceptions. chyma Is usually abundant, thin-walled, and not ligniticd, the annual rings also being mostly indistinct. The characteristic distinguishing the primary and secondary 3i6 A TEXT-BOOK OF BOTAxXY H.wood; X.camb-/^tn: pCoT^::::.:To^[J''^^^^^^ -'^^-^ B' bark; s. sclerenchyma fibers, including wood fibers' o?curr;?-n^',.P^''"f^'Ti ^' "''''^^ ^^^''•' m the bark; t. trachea; m. medullar/rays -X" Me^er ^^'' ^'^''' P^^^^"* MORPHOLOGY OF HIGPIER PLANTS. 317 structures of dicotyledonous roots may be summarized as follows : Primary structure: Epidermis and root-hairs. Hypoder- mis. Primary cortex consisting of parenchyma. Endodermis, pericambium, xylem arranged in radial rays which alternate with phloem or sieve strands, constituting a radial fibrovascular bundle (Figs. 169-174). Secondary structure: Cork cells, phellogen, secondary cor- tex consisting of parenchyma. Phloem, cambium, and xylem arranged in radial groups, forming open collateral fibrovascular bundles. Medullary rays separating the fibrovascular bundles (Figs. 175-177)- Sometimes, as in glycyrrhiza and valerian, a number of paren- chyma cells are found in the center of the root, these constituting the PITH (Fig. 176) or medulla; but they are usually wanting in dicotyledonous roots. Wood and bark are terms used to distinguish those portions of the root or stem separated by the cambium; all that portion inside of the cambium, including xylem. medullary rays, and pith, being known as the wood. The bark includes the hadrome, the medullary rays outside of the cambium, and the tissues formed by the phellogen, vi^., secondary cortical tissue and cork. The following diagram of the secondary structure of a dicoty- ledonous root may be of assistance in understanding the origin and relation of the tissues comprising it : Pith, which may be wanting. Wood made up of Cambium produces -Xylem. Phloem ^Composed of vessels, wood parenchy- \ ma and wood fibers ; or trachcids may replace these cells, or be associated with them. These are arranged in groups forming radial rows which are separated by medullary rays. Consisting of Icptome and companion cells; bast fibers may also be present. These are arranged in collateral groups and form radial rows which are separated by medullary rays. Bark made up of. Meristem of pericambium producing pcricambial- cork and parenchyma. Phellogen later forming periderm in stems several years old, and bork . in the trunk of large shrubs and trees. 3i8 A TEXT-BOOK OF BOTANY. ^&^^t^w^i F,0 x„. A, transverse -ct.on of Phytol^jga^oot sho.,ng the f^^^^^^^^^^ -^tS|j^|?i^Sam„eervsta.^c^ Belladonna root; M. medullary rays. MORPHOLOGY OF HIGHER PLANTS. 319 The root branches arise as the result of the development of primary meristems in the pericambiiim (Figs. 161, 172). The tissues forming the branches are directly connected with the fibrovascular tissues of the root and protrude through the over- lying tissues w^ithout having any connection with them. The structure of the branches thus formed corresponds to the primary structure of the roots, and in the case of dicotyledonous roots may also subsequently develop a secondary structure. Goebel states that in plants which grow in moist soil, or whose roots func- tion only for a short time, the branches may be altogether sup- pressed, as in Colchicum, Arisaema, etc. Contraction of roots is observed in both monocotyledons and dicotyledons, it being most apparent in the former, as in the roots of Veratrum viride (Fig. 178). The uneven or corkscrew- like appearance is due to a contraction, which arises as follows : Some of the longitudinally elongated cells beneath the epidermis, as well as cells extending to and including the endodermis, absorb large quantities of water, which causes them to assume a spherical form (as the cells of a potato are altered on boiling), the result being a longitudinal contraction of the root at this point. In this way the plant is fastened more securely to the earth, and at the end of the season's growth the apical buds of plants, with upright rhizomes, as of Veratrum viride, Dracontium, etc., are drawn into the earth and thus protected during the winter season. Abnormal Structure of Roots. — It is often difficult to recog- nize the type-structure of dicotyledonous roots in drugs, owing to the anomalous and abnormal secondary structure. Scleren- chymatous fibers, while present in glycyrrhiza (Fig. 176) and althaea, are not infrequently wanting. Wood fibers may be spar- ingly developed, as in young belladonna roots (Fig. 177), or even wanting, as in gentian. In other cases the medullary rays are abnormal, being replaced in calumba by wood parenchyma, and in ipecac and taraxacum by sclerenchymatous cells. In asclepias and calumba a layer of stone cells occurs near the periphery ; in gelsemium sieve cells develop in the xylem ; in senega the xylem is not uniformly developed, and in still other cases, as in jalap, pareira, and phytolacca (Fig. 177, A), successive cambiums de- velop, producing concentric series of open collateral fibrovascular bundles. 320 A TEXT-BOOK OF BOTANY. II. THE OUTER MORPHOLOGY OF THE STEM. The stem, or ascending axis of the plant, usually grows in a direction opposite to that of the root, seeking the light and air. The tendency of the stem to grow upward is characteristic of the majority of plants, and is spoken of as negative geotropism. The growing point of the stem is at the apex, and it is protected by a layer of bud scales (Fig. 179, B). Fig. 178. Longitudinal section through a root of Veratruyn viride showing the nature of the contraction of the root: E, epidermis; CS, cells of cortex containing starch; CO, cells of cortex containing raphides; F. hbro vascular bundle; A, rifts or cavities formed as a result of the radial swelling of the cells of the cortex. Stems are further characterized by bearing leaves, or modi- fications of them. The leaves occur at regular intervals in the same species, and that portion of the stem from which they arise is spoken of as a node, while the intervening portion is called an internode. Stem branches usually arise in the axils of the leaves, first MORPHOLOGY OF HIGHER PLANTS. 321 appearing as little protuberances, sometimes spoken of as pri- mordia, on the stem. Their origin differs from that of the root branches, in that they arise from meristematic or embryonic tissue developed just beneath the epidermis. The branches, like the main axis, manifest negative geotropism, although to a lesser degree. They likewise possess a growing point at the apex, covered with embryonic leaves (Fig. 179). Not infrequently more than one branch arises in the leaf axil. Buds may be defined as undeveloped shoots in which the foliage is yet rudimentary. The buds at the ends of stems or Fig. 179. A, longitudinal section through the apical region of the stem of the embryo of a bean (Phaseolus fnultiflorus) \ ss, apex; pb, parts of the two first leaves, and their axillary buds (k, k,); r, periblem or primary cortex. B, diagram of longitudinal section through winter bud of Qit-ercus coccinea: P, growing point; L, young leaves; SB, stem branches; F, fibro Vascular bundle. — A, after Sachs. branches are known as apical, or terminal buds, and those situ- ated in the axils of the leaves, as axillary buds. In some cases they are protected by scales, as in hickory, when they are known as scaly buds ; while buds which are not thus protected are called naked buds. They are further distinguished as leaf, flower, and mixed buds, as they develop into leaves or flowers, or both. We have to distinguish between overground shoots and under- ground shoots. The former are sometimes designated as epi- geous (upon the earth) and the latter as hypogeous (under the earth). 322 A TEXT-BOOK OF BOTANY. Epigeous Shoots. — As would be supposed, these two ki-nds of shoots vary to a certain extent. In epigeous shoots a number of features may be noted. If the internodes are long the leaves do not usually interfere with one another so far as exposure to light is concerned, but if the internodes are short, the leaves are all brought close together on the axis, and hence, were it not for Fig. i8o. A, woody vine of Canada moonseed (Menispermum canadense), which ascends by twining to the right. B, stem of wild yamroot (Dioscorea villosa), which ascends by twining to the left. and several of the characteristic 3-winged capsules at the top. The twining movements of stem climbers are due to the stimulus of gravity rather than to contact stimulus, and in the majority of twining plants the revolving movements, as seen from the side,- are from the left to the right, i.e., in a direction opposite to that of the hands of a watch if represented diagrammatically. various modifications, their relation to light would be very un- equal. Sometimes the shoot-axis may share with the leaves the work of assimilation, as in the case of certain green stems. Then again there are cases in which the leaves are reduced, and the work of assimilation is carried on exclusively by the shoot-axis, as in most Cactacese, certain marsh-plants, and others. On the MORPHOLOGY OP HIGHPK PLak.s. :^^z . ' - ^ H Fig. 219. Pistils and different kinds of stigmas. A, simple (monocarpellary) pistil of willow with lobed stigma; B, compound pistil of Fourcroya with head-like stigma; C, longitudinal section through flower of Spondias with five separate styles and stigmas, only three of which are shown; D, flower of Peperomia showing bristly stigma; E, recurved, thread-like stigmas of the Upas-tree (Antiaris); F. flower of a Canary grass showing the two simple plumose stigmas; G, pistillate flower of couch grass showing the two compouno* plumose stigmas; H, thread-like stigmas of pistillate inflorescence of Euchla-na one of the grasses; J, tri-parted stigmas of the pistillate flower of the castor-oil plant; K, L, two forms of stigmas of Begonia.^Aiter Engler. margins of the carpel forming the ** inner " or ventral suture. In the syncarpous gynxcium the ventral suture of the carpels is directed toward the axis of the flower ; in some cases that portion of the carpel corresponding to the midrib is very prominent, as in the Papilionatae, and has received the name of " outer " or DORSAL SUTURE. There are as many locules in the ovary as there are carpels, 378 A TEXT-BOOK OF BOTANY. and the walls or partitions between the locules of a syncarpous gynsecium are known as dissepiments; when three or more carpels are united the number of dissepiments corresponds to the number of carpels. It sometimes happens that a partition or wall is intruded from the mid-vein of the carpel, dividing a unilocular ovary into one that is bilocular, as in species of Astragalus, and such a partition is termed a false dissepiment. When no other than the true dissepiments exist in the syn- carpous gynaecium the placentas are borne along the axis of the flower and are termed axial placentas. In the Caryophyllaceae the ovules are borne upon a central axis, and the dissepiments having been absorbed by the gynsecium is said txD possess a free central placenta. In other cases the placentas grow backward from the central axis toward the mid-vein of the carpel, carrying the ovules with them, when they are spoken of as parietal pla- centas, as in colocynth fruit and watermelon. The Style not only varies in shape and size but in the manner of attachment to the ovary (Fig. 219) ; it may be very short, as in the clove; long and filiform, as in (Enothera; club-shaped (clav- ate), as in the orange; or broad and petalloid, as in Iris. It is usually situated at the summit of the ovary, when it is said to be apical or terminal; it may, however, be laterally attached, as in the strawberry, or, as in a few instances, attached to the base of the ovary. It is usually smooth, but may be hairy, as in the Com- positae. The styles, like the carpels, may be separate or united, and in the latter case may have a central canal connecting the stigma with the ovary, as in the violets. While usually deciduous, the style may be more or less persistent — forming a part of the fruit — or even become much elongated, as in the dandelion. The Stigma is an essential part of the pistil in that it is the germinating surface for the pollen grains, it being viscid and espe- cially adapted for this purpose (Fig. 219). The stigmas may be separate, as in the Compositae, or they may be united into a more or less club-shaped or globular head, consisting of as many lobes as there are stigmas^ as in the poppy. The stigma, while usually solid, may have an opening, as in the violets, which sometimes has a lid-like appendage, as in Viola tricolor. The Ovules (Fig. 219), as we have already seen, are small MORPHOLOGY OF HIGHER PLANTS. 379 bodies which are borne on the placentas, and which, after f ertihza- tion, develop into seeds. The number of ovules varies considerably — there may be but one, as in the almond, or there may be a large number, as in the watermelon. There are several principal forms of ovules (Fig. 220) recog- nized, of which the following may be mentioned: (i) atropous, in which the ovule is straight and erect on its stalk, as in the Urticaceae ; (2) anatropous, in which the ovule is bent over on to the stalk so as to be in an inverted position, the line of attachment of the ovule and stalk being known as the raphe (Fig. 230, n) ; (3) CAMPYLOTROPOUS, in which the ovule is bent upon itself, as in Stramonium, this form being less frequent than the other two. Most of the ovules of flowering plants are anatropous. Fig. 220. Three positions of ovules. A, atropous; B, anatropous; C, campylotropous. (f) funiculus or stalk; (c) chalaza, or point of union of nucellus and integuments; (k) nucellus or megasporangium; (em) embryo-sac or megaspore; (ai) outer integument; (ii) inner integument; (m) foramen or orifice for entrance of pollen tube, known as the micropyle in the seed; (r) raphe. — After Prantl. Stamen. — As already indicated, the stamen consists of a stalk-like portion called the filament, and a specialized portion which bears the sporangia, called the anther (Fig. 78). The filament may be long or short or wanting. It is commonly thread- like, but varies considerably, and is sometimes leaf-like. The Anther is the essential part of the stamen (Fig. 221) and consists of two lobes, each of wdiich is composed of two divi- sions or pollen sacs (Fig. 79). These sacs contain the pollen, which is commonly discharged either through a longitudinal suture or line of dehiscence, or through an opening at the tip. The anthers may be variously attached to the filament (Fig. 221). When they face the axis of the flower they are said to be introrse, as in the Violaceae, and when they face the perianth they are said 38o A TEXT-BOOK OF BOTANY Fig. 221. Different types of stamens. Abbreviations: filament (f), pollen sacs or iheca (sporangia) (th), connective (c). A, stamens of a water lily {Nymphcea) showing variation in the stamens (a-d) ; B, theca near middle of the stamen of Popowia; C, anther of another species of Popowia with fleshy connective and pollen sacs on either side; D, stamen of Tradescantia with transverse connective; E, F, G, stamens of several Commelinacece with broad connectives; H, stamen of Salvia with peculiar swinging connective and an aborted pollen sac or staminodium (std) at the lower end and the fertile pollen sac above; J, peculiar elongated connective of Unona; K, elongated connective of Humiri; L, androe- cium of violet showing two spurred sessile stamens; M, stamen of Columelia with sinuous confluent anthers, broad connective and short filament; N, confluent transverse pollen sacs of .4 mar Mm; O, united pollen sacs of Columbine showing small connective; P, spherical pollen sacs of Ca//a, with slightly developed connective; Q, versatile anther and long, slen- der filament of dead nettle {Lamium album); R, dehiscence of anther of Solanum by means of terminal pores; S, spurred anther of Arbutus with terminal pores; various kinds of val- vular dehiscence, as in Berberis (T), Atkerosperma (U) and Persea (V). — A, after Caspary; B. H-R, U, V, after Baillon; S. T. after Sachs; D-G, after Schonland. to be EXTRORSE, as in the ^lagnoliaceae ; when they lie horizontally on the tip of the filament, so that they swing as on a pivot, as in the tiger lily, they are said to be versatile ; when they adhere MORPHOLOGY OF HIGHER PLANTS. 381 longitudinally to the sides of the filament and the dehiscence is marginal, they are said to be innate; when they adhere longi- tudinally to the filament and the latter extends slightly beyond them, they are said to be adnate, in which case they may be extrorse or introrse. In some of the Labiatsc the lobes of the anther are united at the apex of the filament, but diverge from the point of attachment and are said to be connate, coherent, or confluent. The Connective is that portion of the filament to which the lobes of the anther are attached or which connects them (Fig. 221 ) ; usually it is not very prominent ; but in some of the Labiatse, as in Salvia, it is rather broad ; in some of the Malvaceae it is entirely wanting, the two lobes being confluent ; in other cases it may be extended beyond the lobes of the anther, as in species of Asarum. Appendages of Anther. — In certain instances the anthers are appendaged (Fig. 221) : In the violets there is a triangular growth at the apex; in the oleander the apex is plumose; in deer berry {Vaccinium staminetim) there are two awn-like append- ages upon the back of the anther; in the violets the two stamens that project into the spurred petal are also spurred and secrete a nectar ; in the Asclepiadace?e the anthers possess wing-like ap- pendages, each sac or division of which contains a pear-shaped coherent mass of pollen grains (pollinium). When a flower has but one stamen it is termed monandroi;s ; and when there are two, three, or many stamens, it is said to be diandrous, triandrous, or polyandrous (Fig. 223). The aggregate of stamens in the flower is called the andrcecium. In the Labi- atae there are four stamens arranged in a longer and shorter pair, and the stamens are said to be didynamous ; in the Cruciferse the flowers possess six stamens, four of which are longer than the other two, and the stamens are described as tetradynamois ; in some plants, as in the Lobeliacese, Papilionatse, etc., the fila- ments cohere, forming groups (Fig. 222) which are termed mona- delphous, diadelphous, etc. ; in the flowers of the potato the anthers lie close together but are not united, forming apparently a continuous ring or band around the pistil, when they are said to be connivent ; in the tubular flowers of the Compositae the 382 A TEXT-BOOK OF BOTANY. anthers are united, forming a closed ring, and the stamens are spoken of as syngexesious ( Fig. 222, A) ; in many of the Cucur- hitacece the filaments and anthers both are confluent ; in the flowers of the Orchidaceae the stamens are borne upon the pistil and are said to be gynaxdrous. Floral Envelopes. — As their name indicates, the floral en- velopes occupy the outermost or lowest position in the arrange- ment of the parts of the flowef. In the bud condition they protect the essential elements, and in the expanded flower are considered to play an important role in securing pollination through the visitation of insects. The floral envelopes are made up generally of two kinds of leaves, petals and sepals (Figs. 224 to 22y). Fig. 222. Union of stamens. A, united anthers of flower of Compositse; B, diadelphous stamens of Pisum with i free stamen and 9 united; several types of monadelphous stamens, as in Erythroxylon (C), Melia Azedarach (D), and common mallow (E). — After Baillon. The PETALS form a spiral which surrounds the androecium. They are, as a rule, quite bright and attractive, being frequently highly colored, as in the rose, Fuchsia, violet, etc., and are known collectively as the corolla. The SEPALS form the next and lowermost spiral. They are usually green and leaf-like, as in the rose and carnation, and together constitute the calyx. Sometimes the corolla and calyx are spoken of together as the periaxth, although, strictly speak- ing, the term has a more special application, and is used mostly in speaking of the sepals and petals of monocotyledonous flowers, MORPHOLOGY OF HIGHER PLANTS. 383 these parts being much aHke and not distinguishable, save in posi- tion, as in certain lilies. Fig. 223 Types of flowers: A, hypogynous flower of flax; B, perigynous flower of cherry, showing perianth tube with sepals, petals and stamens on its border; C, epigynous flower of American sarsaparilla ; D, flower of buttercup showing apocarpous gynascium and large conical torus; E, irregular (bilateral or zygomorphic) flower of aconite showing half of helmet-like sepal (a), other sepals (b, c), long-clawed nectary (k) developed from one of the posterior petals, separate pistils (f) ; F, corolla of Salvia spread open and showing the two rudimentary stamens and two fertile stamens. The connectives in the latter are long and filamentous and each bears at the upper part a normal pollen sac and at the lower end a non-fertile enlarged portion which the insect pushes against in entering the flower and thus causes the pollen to be deposited on its back. — A-C, after Gray; D-F, after Warming. When the divisions of the calyx and corolla remain separate and distinct the latter are spoken of as chorisepalous and chori- PETALOUS, respectively; but when the divisions are united or 3^4 A TEXT-BOOK OF BOTANY. Fig. 224. Lobelia inflata: A. upper portion of shoot showing the dentate-denticulate leaves, the bracted racemes with flowers and inflated capsules, the latter developing soon after fertilization; B, flower showing linear calyx teeth and 2-lipped corolla, the upper lip with 2 rather erect lobes and the lower lip spreading and 3-cleft; C, longitudinal section of flower showing the ovary with ovules (o), style (s), hairy bifid stigma (t),- united stamens (a), corolla (p) and calyx (c) , D, longitudinal section of stamen showing the hairy summit. Scutellaria pilosa: E, branch showing crenate leaves and helmet-shaped capsular fruits; F, capsule after dehiscence showing nutlets (n). G, section of flower of Scutellaria lateriflora showing calyx (c) with crest on one side, 2-lipped corolla (p), the didynamous stamens (s), and 4-locular ovary (n). Spearmint (Mentha spicata): H. showing flowers in slender interrupted spikes; J, flower with bell-shaped calyx, tubular corolla and 2-lobed stigma; K, ellipsoidal poller grains. MORPHOLOGY OF HIGHER PLANTS. 385 coalesced the calyx and corolla are called gamosepalous (syn- sepalous) and gamopetalous (sympetalous), respectively. When the divisions of the calyx or corolla are entirely united these elements are said to be entire, and when the divisions are Fig. 225. Flowers of Solanaceas. Solarium carolinense: A, portion of shoot showing a short raceme of flowers and the spinose leaves and stems; B, diagram of cross section of flower showing sepals (s), petals (p), stamens (a) and ovary (c); C, longitudinal section of flower, the letters the same as in B; D, stamen showing terminal pores; E, two spheroidal pollen grains; F, cross section of 2-locular berry. Hyoscyamiis muticus: G, section of flower showing calyx (c), lobed corolla (p), stamens inserted on corolla tube (s) and ovary (o) bearing at the summit a long style; H, pollen grains in different views; J, portion of stalk with fruits showing cylindrical calyx, the fruit really being enclosed within the calyx and in the nature of a pyxis. partly united they are spoken of as " toothed," " lobed," or " parted," according to the degree of union. In the flowers of the Cruciferse and Caryophyllacese there is a conspicuous stalk to each of the separate petals, which is known as the UNGUIS or claw ; while the upper outspreading portion is known as the lamina or blade. In the gamosepalous calyx and 25 386 A TEXT-BOOK OF BOTANY. the gamopetalous corolla the lower united portion is known as the TUBE, and the upper outspreading portion as the limb or " border.'* The form of the calyx and corolla is quite characteristic for a number of important families. In the Compositae there are two characteristic forms of corolla, namely, the tubular in the disk ^- Fig. 226. APocynum androscemifolium: A, portion of a flowering branch; B, a flower showing the short calyx tube and the corolla with more or less spreading lobes; C, longi- tudinal section of flower: c, calyx teeth; p, corolla lobes; a, anthers; and p, ovary; D, single stamen with long spurs (s). E, a flower of A. cannabinum showing the corolla with ascending lobes. flowers and the ligulate in the ray flowers; in the Papilionatae the corolla, from its fancied resemblance to a butterfly, is de- scribed as PAPILIONACEOUS (Fig. 221, B) ; in the Labiatae the petals are united into two lip-like divisions, and the corolla is said to be BILABIATE (Fig. 223, F). There are two kinds of bilabiate MORPHOLOGY OF HIGHER PLANTS. 387 t floret C ^IkenVZZT °^ ^^^ Compositae. Inula Helenium: A. ligulate floret; B. tubular (h)at th; base ^^''^'""' ^' P°"'" ^'^^"^= E' ""^^^^ ^"^^ers showing hooked hairs F, tubular floret of Safflower (Carthamus tinctorius) . J. hgulate floret of Coltsfoot (Tussilago Farfara) corol^^Tciona''"'^1'' o#a«a/i.).- K. ligulate floret; L. one of the double ha.rs from corona, c, corolla; s, stamens; t, stigmas; p, pappus; h, hairs. 388 A TEXT-BOOK OF BOTANY. corollas — one, as in lavender, where the mouth of the tube Is open^ known as ringent ; and another, where the mouth is closed, as in Linaria, called personate. There are a number of other special forms of calyx and corolla, particularly the latter, and of these may be mentioned the follow- ing : A corolla, like that of the harebell, which is more or less bell- shaped, is termed caaipanulate; a more or less campanulate corolla contracted near the opening, as in Gaultheria, is spoken of as urceolate or urn-shaped ; in the morning glory and other Convolvulacese the corolla is said to be infuxdibuliform or funnel-shaped ; a corolla in which the limb spreads abruptly from the tube, as in Phlox and coffee, is termed hypocrateriforai or salver-shaped ; a corolla with a short tube and outspreading limb, as in potato, is said to be rotate or wheel-shaped ; a rotate corolla with the margin more or less upturned is called crater i- FORM or saucer-shaped ; in aconite the upper petal is hood- or hel- met-shaped, and the corolla is spoken of as galeate ; in the violets one of the petals has a spurred appendage and the corolla is de- scribed as saccate or calcarate, while the modified petal in the orchids is known as the labellum. Duration of Calyx and Corolla. — There is considerable difference in the length of time that the calyx and corolla persist, not only with reference to each other but in different plants. The parts are said to be caducous when they drop from the flower as soon as it opens, as the calyx of the poppy ; when they remain for a day or so, they are said to be ephemeral or fugacious, as in the petals of the poppy ; in the rose and apple the petals fall away soon after the pollen reaches the stigma and they are said to be DECIDUOUS ; in some flowers the petals wither but persist until the maturing of the fruit, as in the Droseraceae, and are known as MARCESCENT ; the calyx may remain unaffected until the maturing of the fruit, as in the Labiatae, when it is said to be persistent. Bracts. — In addition to the floral envelopes, other more or less modified leaves are borne on the flower branch below the flower, frequently at the base of the flower stalk, and these have received the name bracts. The bracts closely resemble the foli- age leaves, but usually are smaller and frequently are mere scales, without chlorophyll. In some cases, however^ they are large and MORPHOLOGY OF HIGHER PLANTS. 389 showy, looking like petals (petaloid), as in the water arum (Fig. 263), the common dogwood; Bougainvillea and Poinsettia seen in greenhouses. The Torus constitutes the terminal portion of the flower axis or stalk, and is usually more or less conical and somewhat enlarged. When the torus is of this shape the parts of the flower are inserted upon it in serial succession, all of the other parts arising below the pistil. It may, however, be modified into a hollow or cup-like structure which grows up around the ovary, carrying the other parts of the flower (sepals, petals, and stamens) with it, thus changing the relative position of the parts, although it should be understood that the ovary occupies practically the same position in the two cases. When the torus is of the first type and the other parts of the flower are inserted below the ovary, the flower is said to be hypo- GYNOUS, as in the orange flower (Fig. 78, A) and the ovary superior ; but when the toriis forms a cup-shaped receptacle and the other parts of the flower arise on its margin above the ovary, the flower is called epigynous, as in the clove (Fig. 78, B ; 223 C) and the ovary inferior. In other cases a ring of leaf-like tissue arises from the torus, forming a cup-like receptacle or tube which is known as the perianth tube, the sepals, petals, and stamens being inserted on its margin. The perianth tube may be free from the ovary, when the flower is said to be perigynous and the ovary half inferior or half superior, as in cherry (Fig. 223, 5) ; or in the case of an epigynous flower it may form a prolongation of the cup-shaped torus. Prefloration or estivation is the arrangement of the parts of the flower — more especially the calyx and corolla — in the bud. Some of the terms used in this connection are also employed in the study of vernation. The following are some of the terms which are employed : Valvate, when the sepals or petals meet each other at the edges, as in Malvaceae; imbricated, when the sepals or petals overlap each other, as in the Magnoliace?e ; plicate or PLAITED, when the divisions are united and folded together, as in the petals of Convolvulus and Datura. The sepals and petals do not necessarily possess the same arrangement, as in the Onagracese, where the sepals are valvate 390 A TEXT-BOOK OF BOTANY. and the petals are convolute. Furthermore, in addition to the principal types of estivation and vernation already given, there are a number of special modifications of these, depending upon the number and arrangement as well as direction of the over- lapping parts of the flower- or leaf-bud. Coalescence and Adhesion. — Not only may the divisions of the same circle or whorl of the flower be united, but even those of different circles, and a number of terms are used to describe these modifications. When the divisions of the same circle are united there is said to be a COHESION or coalescence of the parts. When the divi- sions of different circles are united, as of stamens with corolla, the union is spoken of as adhesion or adnation, as in Convolvulus. Chorisis and Multiplication of Parts. — In contrast with the reduction in number of parts of the flower due to union, there may be an increase in the number of parts due to simple division or splitting of the parts, and this is known as chorisis or deduplica- tion. An illustration of this is furnished by the stamens of the orange flower, where from a single initial stamen or primordium a group of from 3 to ii stamens may be produced. In other cases there may be a multiplication in the number of parts from the beginning, each part arising independently on the torus, as in the stamens of rose. This, of course, would not be termed chorisis, as no splitting or branching takes place. Double Flowers. — In double flowers there is an increase in the number of petals, which is considered to be due to the methods of cultivation and the stimulus of an increased food- supply. This results in several ways: (i) By transformation of the sporophylls, more particularly the stamens, into petals; (2) by division or chorisis of the stamens or carpels with subsequent transformation into petals; (3) by division or branching of the petals; and (4) by the production of new series of petals. The extra petals in double carnations and double roses trace their origin to the stamens, while in Fuchsia they are the result of chorisis of the petals. In the snow-ball ( Viburnum Opulus) and hydrangea the essen- tial elements have undergone a complete transformation, and the flowers, while lar^e and showy, are sterile. In the white water lily MORPHOLOGY OF HIGHER PLANTS. 391 {Nymphcca) there is a series of parts ranging from stamens with narrow filaments and stamens with broad petaloid filaments to petals tipped with a small anther and regular petals (Fig. 221, A). In this case the stamens are considered to result from the trans- formation of the petals. In the case of green roses and green strawberry flowers the petals become green and leaf-like, and the change is spoken of as chlorosis or chloranthy. In some flowers even the ovules are replaced by leaf-like processes or appendages, as in Drosera and clover. Arrested Development. — The arrest or suppression of parts of the plant, particularly of the flower, is of very common occur- rence. Just as there are millions of seeds that never find suitable conditions for germination, so in the flowers of a large number of plants a very large proportion of the ovules never develop into seeds, the plants in many instances not furnishing sufficient nutriment for all of the ovules to mature. Under Leaves it was stated that in the axil of each leaf there is a bud. This is not always apparent, but if the plant be subjected to some special stimulus, some of the latent buds will become evident. For example, the rubber plant (Ficus), so commonly cjltivated as an ornamental plant, shows a tendency to develop a straight, un- branched shoot, but if the tip of the shoot be cut off, the buds in the axils of the upper leaves will develop into branches, while some of those lower down will form small protuberances, but develop no further. In other cases there is a loss of parts which seems to be due to loss of function. When there is a partial loss of the element, as of the anthers in the flower of catalpa, it is said to be imperfectly developed or abortive. When the entire ele- ment remains undeveloped, as in some of the stamens of the Labi- atse, it is said to be suppressed (Fig. 223, F). In flax the stamens of the outer whorl are reduced to thread-like processes. Such sterile or aborted stamens are called stamixodes (staminodia). In other plants the parts are not apparently arrested, but have not yet been differentiated, as is the case in the Lily family, where the perianth is composed of segments which are more or less alike (Fig. 269). In other cases, however, there seems to be a suppres- sion or arrest of the floral envelopes. Cleistogamous Flowers.— In addition to the. regular flowers 39^ A TEXT-BOOK OF BOTANY. some plants produce cleistogamous or closed flowers. In these flowers the corolla is usually suppressed. The flowers develop stamens and pistils but remain closed, and thus there is no chance for cross-pollination. The cleistogamous flowers appear later than the regular flowers and are more or less inconspicuous, developing under the leaves and sometimes underground. Of the plants producing cleistogamous flowers, the following may be mentioned : various species of Viola, Polygala, etc. Classes of Flowers. — As we have seen, the megasporophylls and microsporophylls in the Gymnosperms are borne on separate branches, thus giving rise to two kinds of flowers or cones. While the separation of the stamens and pistils is exemplified in a number of plants in the Angiosperms, still it is not the rule, and these two elements are usually borne close together on the same axis, — i.e., they both enter into a single flower structure. Such a flower is said to be hermaphrodite or bisexual, and most of the conspicuous flowers are of this kind, as roses, buttercups, lilies, etc. Inasmuch as the stamens and pistils constitute the essen- tial elements of the flower, hermaphrodite flowers are also spoken of as PERFECT, providing the stamens and pistils are capable of exercising their generative functions. When the stamens and pistils occur in separate flowers the flowers are said to be uni- sexual or IMPERFECT, as in willow, oak, hickory, etc. A flower having only a pistil or pistils is called pistillate (Fig. 219, A), while one having only a stamen or stamens is staminate, as in oaks. The staminate and pistillate flowers may be borne on the same plant, when it is said to be moxcecious, as in castor bean, chestnut, hickory, alder ; or they may be borne on separate plants, when the plant is called dicecious, as in willows and poplars. Plants bearing hermaphrodite and unisexual flowers on the same individual plant or on different individuals are called polygamous, as in Ailanthus. A COMPLETE flower is one which possesses both kinds of essen- tial elements and both kinds of floral envelopes, and is symmet- rical when a plane can be laid in all directions, the parts being alike, and when the number of parts in each circle is the same or when the n-umber in one circle is a multiple of that in the others ; as a rule, the number of stamens is some multiple of one of the MORPHOLOGY OF HIGHER PLANTS. 393 other parts, as in geranium (Fig. 223), where we find five sepals, five petals, ten stamens, and five pistils. Flowers are also spoken of as regular or irregular, accord- ing to whether all the parts of a circle are uniform in shape or not; the flowers of geranium are regular, while those of violets are irregular. Regular flowers are also spoken of as actino- MORPHic or RADLVL, and irregular flowers as zygomorphic. The latter are also spoken of as dorsiventral. Dorsiventral flowers either arise as such, as in some of the Leguminosae (Fig. 231), or they may arise as radial flowers and become dorsiventral dur- ing the course of development, as in willow herb (Fig. 224). In some flowers the floral envelopes are wanting, and the flowers are said to be naked, as in the willows and grasses. Anthotaxy. — The study of the arrangement of flowers on the stem is known as anthotaxy. The flowering axis may bear only a single terminal flower, as in Tulipa ; or the flowers may occur singly in the axils of the leaves, as in Viola canadensis. When, on the other hand, the flowers are borne upon a branch shoot, the internodes of which are more or less condensed, and the leaves smaller and of a more simple structure than the foliaceous leaves, the whole shoot is known as an inflorkscexce, and the leaves are called bracts. The flower thus represents a single unbranched shoot, while the inflorescence represents a branched or ramified shoot. The so-called bracts, besides being generally smaller than the leaves proper, are mostly sessile ; they may, however, be green, or membranaceous, or they may exhibit a bright coloration, as in Monarda. The stalk of the individual flower is called a pedicel, and may be naked, or bear one or two small bracts, which are called fore-leaves or prophylla. In the monocotyledons there is usually only one fore-leaf, which turns its back to the mother-axis and is frequently two-nerved and two-keeled. In the dicotylerlons there are generally two fore-leaves, which are placed to the right and left of the flower, as in the violets. The position of the floral leaves (the sepals, the petals and those of the perianth) depends upon the arrangement of the fore-leaves, so that in most of the monocotyledons, where there 394 A TEXT-BOOK OF BOTANY. is one mediane prophyllon, the first leaf of the perianth is placed on the front, while the two succeeding leaves of the perianth occupy a position of 120° from this (Fig. 254 j. When, on the other hand, as in the dicotyledons with pentamerous flowers, two fore-leaves are developed, the first floral leaf (sepal) is situated obliquely above the last fore-leaf, usually on the frontal part of the flower; the second sepal is directly behind the first or diagonally opposite to it, the remaining three leaves (sepals) occurring in a spiral of two-fifths (Fig. 280). Several deviations from this type occur, as in Lobelia (Fig. 224), Polygala, etc. Two types of inflorescence are distinguished: (i) The in- definite, in which the flowers open or develop in acropetalous or centripetal succession, and (2) the definite, in wdiich the flowers open in basipetalous or centrifugal succession. The in- definite type of inflorescence is seldom terminated by an ex- panded flower, and two classes of this type are distinguished : (a) Those in which the flowers are pedicelled, as in the raceme (Fig. 267) and umbel (Fig. 344), and (b) in which the flowers are sessile, as in the spike (Fig. 230) and head (Fig. 228). The RACEME is a long inflorescence with pedicelled flowers, which are frequently subtended by bracts (Figs. 224, 225, and 293). The CORYMB is a modified raceme in which the pedicels of the basal flowers are much longer than those of the apical, and thus the inflorescence looks like an umbel. In the milkweed the flowers have pedicels of the same length which arise from the apex of the shoot or peduncle, and this form of inflorescence is known as an umbel. In the Umbelli ferae a flower cluster or umbellet takes the place of the individual flowers of the umbel, and is known as a compound umbel (Figs. 346-348). The spike is also generally a long inflorescence, the flowers being sessile (Fig. 230, illus. 3), the secondary spikes in grasses being known as spi relets. The spadix is a form of spike, w^hich is readily distinguished by the fleshy stem, in which the flowers are frequently deeply imbedded, and wdiich is frequently surrounded by a large bract, the so-called spathe, as in Arissema. The catkin is a kind of spike with small, often imperfect flowers, which falls off as a whole, as in the staminate catkins of the oak. The catkins are mostly decompound, and in some species MORPHOLOGY OF HIGHER PLANTS. 395 of Populus the single flowers are pedicelled, and hence are actually racemose rather than spicate inflorescences. In the head and the umbel the main inflorescential axis is exceedingly short and the innermost flowers are often destitute of bracts, in contrast with the external, w^hich are frequently provided with bracts that are of quite considerable size. Sterile bracts also occur in these two types, and are called involucral leaves, as in Cormis Horida, where they are white or pink. There is also a difference in sex of the outer and inner flowers. While the head occurs as typical inflorescence in the CompositcC, it also exists in some of the Umbelli ferae. The flowers of the Compositor are borne on a common torus, known as the disk, which is subtended by one or more circles of bracts, these constituting an involucre. The flowers are of two kinds, and they receive different names because of their form and position. Those situated near the margin of the disk are known as RAY-FLOWERS, and because they possess more or less strap- shaped corollas are also known as ligulate flowers. Those occupying the central portion of the disk are known as dlsk- flowers, or as tubular flowers because of the tubular shape of the corolla. Most of the Compositse possess both ligulate and tubular flowers, as Arnica, Matricaria (Fig. 228), the common daisy, etc. But some of the members of the family have only ligulate flowers, as chicory and dandelion, and a relatively few have only tubular flowers. Two types of definite inflorescence are distinguished : ( i ) the dibrachious (bifurcate) cyme in which the inflorescence represents a series of very regularly arranged lateral axes, one on each side of the terminal or median flower, as in the Caryo- phyllacese; and (2) the monobrachious (simple) cyme, of which there are several modifications, but common to all of them is the development of only one lateral branch to each terminal flower. In the scoRPioiD cyme the lateral axes are arranged alternately to the right and left, while in the helicoid cyme the lateral axes are all on the same side of the main axis, as in Hypericum. The so-called flower cluster is a cymose inflorescence of either the definite or indefinite type in which the flowers are almost sessile or very short pedicelled, as in Chenopodium, Juncus, etc. Some^ 396 A TEXT-BOOK OF BOTANY. times the inflorescence may be decompound or complex, as in several Composit?e, where the heads may be arranged in cymes or racemes; or, as in the Graminese, where the spikelets, which Fig. 228. Matricaria: A, longitudinal section of head showing torus (a), involucre (b), ray florets (c) and disk florets (d). B, head with the florets removed, showing the long conical torus and the involucre (H). C, tubular floret showing the ovary (f) with glandular hairs (Di) and the embryo (S), which develops after fertilization; style (g) and bifid stigma (N), the surface of which is covered with hairs; n, nectaries; b, corolla tube with narrow lobes (a); stamens showing filaments (st), united anthers (A) and apex of connective (sp). D, ligulate floret showing ovary (F), and bifid stigma (N); tube of corolla (R) and the upper ligulate portion (Z). — After Meyer. are spikes, may be arranged in panicles, i.e., branched racemes; or finally, as in Cryptotaenia (Umbelli ferae), where the umbels are arranged in cymes. MORPHOLOGY OF HIGHER PLANTS. 397 Pollination and Fertilization. — Fertilization represents the final stage in the work of the flower as a whole, and has already been defined as the union of the egg-cell and a male nucleus. Pollination may be considered to include the transferral of the pollen grains from the anther to stigma and their subsequent germination thereon, this latter process resulting in the produc- tion of the male nuclei. Pollination thus represents but one series of changes or processes which precede fertilization, for, while the pollen grain is going through the various stages in development which lead to the formation of the male nuclei, a series of com- plex changes are going on in the embryo-sac leading to the develop- ment of the egg-cell. Our special interest in pollination arises from the fact that the pollen grains are not retained in the pollen sacs and are dependent upon various agencies for transferral to the stigma. This is a matter of great biological significance, for it is claimed that many of the special characters of flowers have a direct relation to pollination. The various ways in which the anthers open for the discharge of the pollen when it is ripe have already been considered (Fig. 221), but it may be added that the manner in which this is done usually appears to have a relation to the manner in which the pollen is to be carried to the stigma. In order that pollination may be effected, the stigma must be ripe or mature, when it is said to be receptive. It then usually secretes a sticky, sugary liquid which causes the pollen grains to adhere to the stigmatic surface (Fig. 83), and which at the same time serves as a nutrient to them. Usually the pollen grains begin to germinate in a short time after reaching the stigma, which is made evident by the pro- trusion of the pollen tubes. The stigma seems also to have the power of selection, for in many cases the pollen does not germi- nate as readily on the stigma of the same flower as on that of another flower, provided it be of the same or a nearly related species. When a flower possesses both stamens and pistils, — that is, is bisexual or hermaphrodite,— and its pollen germinates upon its own stigma, the process is known as close or self-pollination, and if fertilization follows, this is known as self-fertilization. 398 A TEXT-BOOK OF BOTANY. While most hermaphrodite flowers are self-pollinated, there are some that are not, and this is brought about in several ways : ( I ) As already pointed out, the pollen may germinate better on the stigma of another flower than on the stigma of the same flower. (2) The anthers and pistils of the same flower may mature at different times, and this is one of the commonest ways of preventing self-pollination. Usually in such cases the stamens mature first. The common plantain (Plantago) furnishes an example of the maturing of the stigma before the anther. The flowers of this plant are arranged in spikes (Fig. 230, illus. 3 and 4) which belong to the indefinite class, and hence the lower flowers on the spike expand first. As stated, the pistil of each flower matures first, and after it withers the stamens protrude and discharge their pollen. It is evident that the flowers can not be self-pollinated, nor is it likely that one flower will be pollinated by another of the same spike. (3) The stamens and pistils of the same flower may vary in length, as in Polygonum (Fig. 230, illus. I and 2) and Lythrum (Fig. 230, illus. 5), or stand in such other relation to each other that self-pollination will not be effected, as in some of the irregular or zygomorphic flowers, like those of Orchids. In these several cases the pollen grains either fall upon or are carried by various agents to the stigmas of other flowers, and this is known as cross- pollination, and the fertilization which follows as cross-fertilization. Cross-fertilization is an advantage to the species, for usually the seeds which result from this process give rise to plants which are more vigorous and otherwise superior to those which result from self-fertilization. In some cases, in order to insure the pro- duction of fruit, hand-pollination is practised, as by the growers of vanilla and some other tropical plants of economic importance. In the case of unisexual flowers, or those in which the stamens and pistils are in separate flowers, there is, of course, no chance for self-pollination. Here, as in the case of cross-pollinated her- maphrodite flowers, pollination may be more or less close or it may be remote, as between flowers of the same cluster or inflores- cence, between flowers of different clusters or inflorescences on the same plant, or between flowers on different plants. In buckwheat (Fig. 230, illus. i and 2) and partridge berry MORPHOLOGY OF HIGHER PLANTS. 399 (MitcJiella repens) two kinds of flowers are produced, viz.: (a) one with short styles and long filaments, and another [h) with long styles and short filaments, and thus the flowers appear to be especially adapted for insect cross-pollination and are called DIMORPHIC. In still other cases one species gives rise to three kinds of flowers, depending upon the dift'erence in the relative lengths of the styles and filaments, as in the purple loosestrife (Lythruni calcaratiim) , and such flowers are called trimoki'iiic. .The external agents which are instrumental in carrying ])ollen from one flower to another and thereby promoting cross-pollina- FiG. 229. Visitation of flowers by insects showing how they gather the pollen and assist in cross-pollination, the one on the left being Lilium Martagon visited by a hawk moth, showing that while the proboscis is removing honey from the nectary the under side of the body is becoming covered with pollen; at the right Cydonia vulgaris, the common quince, visited by a bee, whose legs are becoming covered with pollen. — After Dodel-Port. tion are the wind, water currents, insects, small animals and birds, such as humming-birds, which are, even in temperate regions, to be observed visiting the garden nasturtium. In many of the early-flowering trees, as well as pines, Indian corn, etc., the flowers are devoid of showy, attractive features, but produce large quantities of pollen which is more or less dry and powdery and carried by the wind to other flowers. Flowers which are wind-pollinated are classed as anemophilous, and it is estimated that about one-tenth of all the flower-producing plants belong to this class. Plants which are pollinated by the aid of water currents are 400 A TEXT-BOOK OF BOTANY Fig. 230. Manner of cross- pollination in some hermaphrodite flowers, i, 2. Flowers of buckwheat, showing long style and short filaments in i, and short styles and long filaments in 2: a, anthers; st, stigmas; n, nectaries. 3- Spike of plantain showing maturing of stamens, below and pistils above. 4, Dissected flower of plantain: b, bract; c, calyx; p, corolla tube; s, stamens; t, protruding withered style. 5. Flowers of Purple willow-herb {Lythrum Salicaria), one side of the perianth removed from each. A is long- Btyled, B. medium-styled, and C, short-styled. The direction of the arrows and dotted lines indicates the best methods of crossing. — i, 2,5, adapted from Warming. MORPHOLOGY OF HIGHER PLANTS. 401 Fig. 231. A, flowering and fruiting plant of peanut (Arachis hypogcpa). After fertiliza- tion the carpophore (or stalk between calyx and ovary) grows in length, sometimes 4 to 8 cm., and curves downward penetrating the soil (el), after which the fruit develops. B, longitudinal section through the papilionaceous (bilateral) flower; C. longitudinal section through the pod (peanut).— After Taubert. known as hydrophilous, and under this head are included those plants which live under the water and those that produce flowers at or near the surface of the water. Those plants which depend upon the visitation of insects for 26 402 A TEXT-BOOK OF BOTANY. the transferral of tlie pollen in cross-pollination are called ento- MOPHiLOUS (Fig. 229). They frequently possess bright, highly colored flowers, and it is considered that these serve as an attrac- tion to the insects which visit them. The insects are, however, probably more attracted by the odor and food products which they obtain, such as the nectar. The nectar is secreted by glands known as nectaries, which are variously located ; frequently they are on the torus, either between the ovary and stamens (Fig. 78) or between the stamens and petals. Sometimes the stamen is modified to a nectar-secreting spur, as in the violets. In aconite the nectary is developed from one of the posterior petals (Fig. 223, E). In seeking the nectar the pollen of the ripe anther may fall upon or adhere to the insects and thus be carried from one flower to another (Fig. 230). Honey is a product formed through transformation of the plant nectar by honey bees. The nectar is supposed to be acted upon by certain salivary secretions of the bee and changed into a fruit-sugar, the so-called honey, consisting of a mixture of dex- trose and levulose. The nectar of buckwheat and clover (partic- ularly white clover) is the principal source of the commercial article. The nectar of some plants is poisonous and may furnish a poisonous honey (see discussion under Ericaceae). THE INNER STRUCTURE OF THE FLOWER. The inner structure of the flower bears a close resemblance to that of the stem and leaf. The bracts in almost all particulars are like the foliage leaf of the same plant, and the flower stalk closely resembles the foliage stem. The calyx, while resembling the foliage leaf, usually contains calcium oxalate in greater amount, and the chlorenchyma consists wholly of rather loose chlorophyll parenchyma ; the outer or under epidermis contains the stomata, and if hairs are present, they also arise from this surface ; the fibrovascular bundles are generally simple in structure, although in some cases, as in lavender, sclerenchymatous fibers are strongly developed. In the COROLLA the epidermal cells are generally more or less centrifugally developed, forming prominent papillae (Fig. 232, A, B), which give the petals a velvety or satiny appearance, as in MORPHOLOGY OF HIGHER PLANTS. 403 the rose; glandular and non-glandular hairs are also developed which are peculiar to the corollas of irregular flowers, as in La- vandula vera and Viola tricolor (Figs. 124, 149-155, 232) ; stomata are comparatively few in number. The epidermal cells Fig. 232. Inner morphology of the flower as illustrated in Viola tricolor. A, epider- mal cells from the outer surface of the spurred petal showing papillae; B, epidermal cells from the under surface of the petals, some of the cells showing centripetal thickenings, the two without thickenings indicating the epidermal mucilage-cells; C, epidermal cells from the under surface of the petals showing a zigzag outline and short centripetal thickenings; D, surface view of the mesophyll of the petals; E, corkscrew-like hair from the i'nner sur- face of the spurred corolla near the throat; F, a hair from the edge of an anther; G, epider- mal cells of the anthers; H, surface view of the mesophyll cells from the spurred stamen showing collenchymatous thickening; I, surface view of cells of endothecium; K, pollen grain viewed from the side; L, pollen grain examined in water; M, pollen grain observed in chloral solution. are but slightly cutinized, and in surface view are strongly undu- late and appear striate owing to the papillose development ( Figs. 232 and 235). The chlorenchyma is made up of rather loose, branching parenchyma cells (Fig. 232, D), with large, intercellular spaces. The cells are free from chloroplastids, may contain 404 A TEXT-BOOK OF BOTANY. chromoplastids, or, like the epidermal cells, a colored sap ; in some instances, as in the buttercups, starch grains are also found in the mesophyll. Calcium oxalate crystals are usually present, and milk vessels are sometimes found,, as in the Papaveraceae. The FILAMENT and connective possess a central fibrovascular bundle, around which are arranged comparatively small paren- chyma cells and among which secretion cells are sometimes scat- tered, as in Tilia. The pollen sacs consist of but two layers of cells — an outer layer called the "exothecium," which resembles the epidermis of the corolla, and an inner layer called the " endo- thecium," the cells of which are contractile and peculiarly thick- ened, this feature being rather characteristic for certain species (Fig. 22,2, I). Lining the pollen sacs during their development, Fig. 233. Several forms ot pollen grains: A, crocus; B, arnica, with three thin places in the wall through one of which the pollen tube may protrude; C, lavender showing six thin places in the wall. there is a layer of cells, called the '' tapetal cells " ; but these are usually sooner or later absorbed. The POLLEN GRAINS vary greatly in number, as well as in size and shape. They are usually more or less ellipsoidal, but may be spherical, as in Crocus (Fig. 233, A) ; more or less three- sided, as in the Compositse and in cloves ; four- or five-sided, as in Viola tricolor (Fig. 232, K, L, M), and in some cases, as in the Pinacese, they may be winged. In addition to protoplasm and one or more nuclei, pollen grains contain considerable oil and starch. The outer or enclosing membrane (Fig. 233) consists of two parts: an inner one, known as the " intine," and consisting of cellulose, and an outer, known as the '' exine," apparently con- sisting chiefly of cutin ; in some cases the exine also contains an oil which is colorless, as in Salvia, or yellowish, as in lavender, and in some instances it may contain a viscid substance, causing: MORPHOLOGY OF HIGHER PLAXTS. 405 the pollen grains to adhere, as in CEnothera. The grains may be smooth or variously sculptured ; in most instances the exine is unevenly developed, leaving thin places through which the pollen tubes protrude in germination; these give the appearance of Ftg. 234. A, Crocus (Spanish saflfron) showing two spherical pollen grains, a fragment of stigma with papillae, and fragment of an anther; B, Calendula showing 3 spinose pollen grains and fragment of corolla, the cells of which contain oil-like globules; C, Carthamus (so-called American saffron) showing 2 slightly spinose pollen grains and a fragment of the corolla with brown laticiferous vessels and numerous unicellular hairs. — After Weakley. grooves when the grains are dry, and the number of grooves is characteristic for different species ; in most of the Compositae they are three in number ; in the Labiatae there are six, while in Crocus they are wanting (Fig. 234). The epidermal cells of the stigma are quite characteristic. 4o6 A TEXT-BOOK OF BOTANY. The cells of the epidermis, or so-called " stigma-epithel," may be palisade-like, forming a more or less wart-like mass, as in the viscous stigmas of the Umbelliferse, or the outer walls may be modified to rather broad papillae, as in matricaria and arnica, or they may be developed into hair-like processes, as in crocus. The pollen tubes either enter the style through an open canal, as in the violets, or they penetrate into the conducting tissues of the style, either through the papillae, as in malva, or through the middle lamella of two neighboring papillae, as in Atropa Belladonna. The important tissue of the style is the conducting tissue ; in styles which are hollow it forms the lining of the canal, the cells resembling those of the stigma-epithel; in styles that are solid the conducting tissue occupies the central axis and consists of somewhat elongated cells, the walls of which are generally thick, frequently strongly refractive and possess the property of swell- ing, being furthermore separated by large intercellular spaces. Surrounding the conducting tissue are thin-walled parenchyma cells, in which the fibrovascular bundles are distributed, the num- ber of groups of the latter corresponding to the number of carpels that compose the gynaecium. There may also occur secretion cells, containing mucilage, as in malva, or oil and resin, as in matri- caria. Occasionally, the parenchyma is replaced either in part or entirely by mechanical cells, and the epidermal cells may be modified to hairs. The tissues of the ovary are, as a rule, in a very rudimentary condition ; in fact, so rudimentary that it is difficult to distinguish the ovaries of two flowers that develop into quite different fruits. In some instances it is said that, notwithstanding the subsequent changes, each cell of the fruit is already indicated in the ovary. The ovary possesses an outer and an inner epidermis ; the outer is provided with stomata and may also possess hairs ; the inner may also have stomata and after fertilization may develop secre- tion hairs, as in the orange. Between the epidermal layers occur thin-walled parenchyma cells which contain leucoplastids and chloroplastids, and in which the fibrovascular bundles are dis- tributed, these being usually simple, or complex, as in the pea. The number of fibrovascular bundles is more or less dependent MORPHOLOGY OF HIGHER PLANTS. 407 Pig 2^=; Inner morphology of flower of Primula officinalis: A papillae on stigma of fioie'r with long styles B. papilla from stigma of flower with short styles; C sec- papillse; F. a pollen grain.— Redrawn d. d. pharm. Ges., 1907, P- 352. by Haase from drawing of Hans Kramer Ber. 4oB A TEXT-BOOK OF BOTANY. upon the number of carpels that make up the gynaecium ; as a rule, there is a strong fibrovascular bundle which corresponds to the mid-vein of each carpel. The PLACENTA is a development from the inner epidermis. It is traversed by a fibrovascular bundle from which branches are given off to the individual ovules ; it may have a conducting tissue similar to that found in the style, and in some cases the epidermis of the stalk of the ovule may be developed to a stigma-epithel. The OVULE not only possesses a distinct form as already given, but the internal structure, by reason of the changes associated with fertilization, is more or less characteristic for certain species and genera. It has an epidermal layer, the outer walls of which are more or less cutinized, and it consists for the most part of paren- chyma cells rich in protoplasm and food-materials ; in addition the embryo-sac contains a number of nuclei. The stalk and raphe are connected with the placenta by means of a fibrovascular bundle. The NECTAR may be secreted by certain of the epidermal cells of various parts of the flower ; these may resemble the ordinary epidermal cells or they may be modified to papillae, as in the spurred stamens of the violets, or to hair-like processes, as in malva. The cells which secrete nectar constitute the " nectar- apparatus," and the walls are usually thin and more or less cutin- ized. The nectar-apparatus is found more generally upon some part of the stamen, but the sepals and petals are not infrequently saccate or spurred, which adapts them for holding the nectar. V. OUTER MORPHOLOGY OF THE FRUIT. After the fertilization of the ovule or ovules, the parts of the flower that play no further part either in protecting the seed or aiding in its dispersal soon wither and are cast off ; in most flowers the petals lose their color and, together with the stamens, style, and stigma, wither and fall away shortly after fertilization. The stigma may, however, persist, as in the poppy ; the style may like- wise remain, as in Ranunculus, or even continue to grow or lengthen, as in Taraxacum; in other cases the calyx persists, as in orange and belladonna ; in still other cases the torus may be- come fleshy and form a part of the fruit, as in pimenta and apple. The fruit may consist, therefore, not only of the ripened pistil, MORPHOLOGY OF HIGHER PLANTS. 409 a^^ Pig. 236. Different types of fruits. A, silique of mustard showing the separation of the two valves leaving the seeds attached to the central axis; B, spinous capsule of Stra- monium showing septifragal dehiscence into four valves, the capsule being strictly 2- locular but apparently 4-locular owing to the formation of false dissepiments; C, s-valved capsule of Geranium in which the carpels become detached from one another and roll up- wards remaining attached to the beak-like compound style; D, capsule of Hyoscyamus showing transverse dehiscence by means of a lid (i) and the two loculi containing numerous small seeds; E, fruit of strawberry showing fleshy torus and numerous embedded akenes; F, silicula of shepherd's-purse showing seeds attached to central axis and longitudinal dehiscence of the valves which remain attached below; G, fruit of rose, so-called rose "hip," the akenes being enclosed by the hollow oval torus which shows remains of calyx at the apex; H, multiple fruit of mulberry composed of small drupes, the pulpy portion of each consisting of the fleshy perianth. — Adapted from Warming. but also of other parts of the flower and torus which persist oi develop with it. 4io A TEXT-BOOK OF BOTANY. The wall of the fruit is called the pericarp, and, like the leaf, it consists of three distinct layers, viz. : ( i ) the outer layer corre- sponding to the outer epidermis of the ovary is called the epicarp or EXOCARp; (2) the inner layer corresponding to the inner epidermis of the ovary is called the endocarp, or, from the fact that it is sometimes hard and stone-like, it is called the putamen, as in the prune; and (3) the middle layer situated between the epicarp and endocarp is called the mesocarp ; and from the fact that it is sometimes succulent or fleshy, as in the prune, it is also called the sarcocarp. There are a number of distinctive and descriptive names applied to fruits. Some of the more imoortant are as follows : Fig. 237. A, transverse section of colocynth showing seeds (s) borne on parietal placentas; B, transverse section of fruit of Ricinus communis showing septicidal dehis- cence of capsule, the seeds (s) being borne on axial placentas; C, transverse section of card- aniom showing loculicidal dehiscence, the seeds (s), as in B, being borne on axial placentas. An Achene is a non-fleshy, or so-called dry, unilocular and one-seeded, indehiscent fruit, in which the pericarp is more or less firm, and may or may not be united with the seed. Achenes may be inferior, as in the Compositse (Fig. 227), where they develop from inferior ovaries, being frequently surmounted by the pappus or calyx; or half inferior, as in the rose (Fig. 236, G)y where they develop from half inferior ovaries ; or superior, as in the buttercup (Fig. 223,/)). A Berry is a fleshy, indehiscent fruit, the seeds of which are embedded in the sarcocarp; berries are superior when they develop free from the torus, as in belladonna (Fig. 239), capsi- cum, grape, etc., and inferior when the torus forms a part of the fruit, as in banana, cranberry (Fig. 244), and gooseberry (Fig. 245). MORPHOLOGY OF HIGHER PLANTS. 411 A Capsule Is a dry, dehiscent fruit, consisting of two or more united carpels. Dehiscence in capsules may occur in five different ways: In the castor-bean (Fig. 237, B) the carpels separate from each other along the walls or septa (dissepiments), the seeds being discharged along the ventral suture of the separated carpels, and this mode of dehiscence is called septicidal. In mustard (Fig. Fig. 238. Capsules of poppy (Papaver somniferum) , whole and in transverse and longitudinal sections, showing dissepiments and remains of radiate stigmas at the apex, which are porous and through which the seeds are discharged, i, French capsules; 2, German capsules. 236, A) the dissepiments remain intact and dehiscence occurs along the margin of the capsule, and is therefore called marginiciual ; but as the partial carpels (or valves, as they are termed) separate from the walls or septa, the dehiscence is also known as septi- FRAGAL. In cardamom (Fig. 237, C) the septa as well as valves are united, and at maturity the latter separate and dehisce at points in the margin corresponding to the mid-vein of the carpel, and 412 A TEXT-BOOK OF BOTANY. this form of dehiscence is known as locultctdal. In poppy capsules (Fig. 238) there are a few openings beneath the united Fig. 23Q. Several forms of fruits: A, branch of Apocynum androsaemifolium showing numerous flowers and a single fruit with 2 long, slender follicles. Comparative size of follicles in A. androsamifolium (B), and .4. cannabinum (C). Branch of Solanum carolinense showing a number of small superior berries (D). Pyxis of Scopolia carniolica showing slightly lobed calyx and upper portion of fruit (E). Pyxis in Hyoscyatnus niger showing calyx lobes extending much above the fruit (F). Berry of Atropa Belladonna cut trans- versely and showing the numerous small seeds (G). Young spinose capsule of Datura Stramonium (H). stigmas through which the seeds are expelled, and this form of dehiscence is known as porous. In hyoscyamus (Fig. 2^6, D) a, MORPHOLOGY OF HIGHER PLANTS. 413 portion of the capsule comes off from the remainder hke a hd, and this form of dehiscence being circular or transverse to the 1st II A.^ ..^ qst Fig. 240. The fruit of the cocoanut palm (Cocos micifera): I. ripe cocoanut fruit showing lower part of axis forming the stem (S). upper end of axil with scars of male flowers (A), epicarp (Ep), mesocarp (M) with fibers, endocarp or hard shell (E). portion of testa adhering to endosperm (T). endosperm surrounding cavity of nut (Alb) and germinating eye (K); II. longitudinal-radial section of endocarp through the stone cells and edge of bundle showing transversely elongated and isodiametric stone cells (qst). longitudinally elongated stone cells (rst). thick-walled porous cells (f). pitted tracheae (g) and spiral trachea (sp) ; III, longitudinal section of a large (mesocarp) fiber showing stegmata (ste). silicious body (Si), bast fibers (f). tracheids with small pits (t), tracheids with large pits (f). spiral tracheae (sp). reticulated tracheae (r), scalariform trachea? (sc), sieve tube (s) and cambiform cells (c and c')- — After Winton. sutures of the carpel, it is called circumcissile. this kind is known as a Pyxis or Pyxidium. A capsule of 14. A TEXT-BOOK OF BOTANY, Em End — mes Fig. 241. Fruit of the huckleberry {Gaylussacia resinosa): I, fruit seen from above; II, transverse section of fruit; III, stone; IV, transverse section of stone showing endocarp (End), testa (S), endosperm (E) and embryo (em); V, transverse section of outer portion of the'pericarp showing epicarp (epi), hypoderm (hy), mesocarp (mes) and stone cells (st) ; VI transverse section of endocarp and seed showing large isodiametric stone cells (End) narrow longitudinally extended fibers (If), testa (S), hyaline layer or nucellus vN; and endosperm (E). — After Winton. MORPHOLOGY OF HIGHER PLANTS. 415 Fig. 242. Cultivated strawberry (Fragarta chilo?nsis): I. Compound fruit showing fleshy receptacle bearing the achenes in deep depressions ; II. isolated achenc ; III. achene showing style (Sty), stigma (Sti) and connecting bundle (B); IV, achcnc in transverse section, pericarp (F), testa (S), raphe (R), endosperm (E) and embryo (Em); V, receptacle in surface view showing epidermis (Ep), with hair (h), and stoma (sto); hypoderm (hy) and sphero-crystals (k) ; VI, achene in transverse section showing pericarp (F) consisting of epicarp (epi), mesocarp (mes). spiral vessels (sp), crystal layer (k). outer endocarp (If) with longitudinally extended fibers and inner endocarp (qf) with transversely extended fibers; testa (S) consisting of epidermis (ep) with reticulated cells, elongated brown cells (br), hyaline layer or nucellus (N) and endosperm (E) consisting of a single layer of aleurone grains; VII, style and stigm.a. — After Winton. 4i6 A TEXT-BOOK OF BOTANY Fig. 243. Red Raspberry {Rubus IdcEus): I, Compound fruit consisting of a number of drupelets crowded together on the top and sides of the receptacle; II, transverse section of a drupelet showing'epicarp (epi), hypoderm (Hy), mesocarp (Mes), outer endocarp (F), inner endocarp (F'), testa (S), raphe (R), endosperm (E), and embryo (Em); III, stone including endocarp and seed; IV, stone somewhat magnified; V, style and stigma; VI, surface section of epicarp showing straight hair (h'), sinuous hairs (h) and stoma (sto) ; VII, transverse section of endocarp and seed showing endocarp (End) consisting of longi- tudinally extended fibers (If), transversely extended fibers (qf), testa (S) consisting of epidermis (ep), parenchyma or nutritive layer (p), and inner epidermis (iep) ; hyaline layer or nucellus (N), endosperm (E) with aleurone grains (k). — After Winton, MORPHOLOGY OF HIGHER PLANTS. 417 A Caryopsis, or Grain, is an indehiscent, non-fleshy fruit possessing a thin pericarp, which is closely adherent to the thin seed-coats, as in wheat, corn, and other Gramine.T (Figs. 255.256). © n Fig. 244. The fruit of the cultivated cranberry {Vacciniutti macrocarpon): I, berry seen from above; II, transverse section of berry; III, single seed; IV. transverse section of seed showing outer epidermis (S), inner layer of seed-coat (S'). raphe (R), endosperm (E) and embryo (Em); V, surface section of endocarp with stoma; VI, seed in transverse sec- tion showing epidermis of seed-coat (ep) with sclerenchymatized and mucilaginous layers, inner layer of seed-coat (m) and endosperm (E); VII, surface section of epidermis of seed- coat. — After Winton. A Cremocarp is a dry, indehiscent fruit which consists of two inferior achenes, known as meuicarps; these are separated from each other by means of a stalk known as a carpophore. 27 4i8 A TEXT-BOOK OF BOTANY. Fig. 24s. The fruit of the American Gooseberry (Ribes oxyacanthoides): I, whole fruit; II, transverse section of fruit with seeds; III, seeds deprived of gelatinous coat; IV, floral parts; V. surface section of epidermis from margin of calyx with hairs; VI, surface section of epidermis from throat of calyx with hair. — After Winton. This fruit is characteristic of the Umhelliferce. (Consult Vokime II for pharmacognosy of medicinal umbelliferous fruits.) A Drupe is a fleshy, indehiscent fruit with a more or less succulent and well-developed sarcocarp and an indurated endo- AlORPHOLOGY OF HIGHER PLAXTS. 419 carp. Drupes are superior when they are free from the torus, as in prune; inferior when the torus forms a part of tlie fruit, as in pimenta. Drupes are also spoken of as " dry " wlien tlie sarco- carp is less succulent, as in KJiiis glabra, or when tliey are col- lected unripe, as in pepper, pimenta, and cubeb. The fruits of the raspberry and blackberry consist of a collection of little drupes, the whole being known as an et.erio. In the blackberry the drupelets cohere with the fleshy torus, while in the raspberry the drupelets cohere with one another, forming a cap which is sepa- rable from the cone-shaped torus. H the drupelets of tiie rasp- berry are examined closely it w^ill be found {Fig. 243) that each has from 4 to 7 facets on the sides formed by the pressure of the adjoining drupelets. These facets are usually slightly convex or concave. Tschierske states that the individuals cling together, first, because of- the closely-fitting adjoining facets, the slightly convex surface of one fitting into a corresponding concave surface of another; and, second, because of the interlocking of the sinuous hairs. A Follicle is a dry, dehiscent fruit which consists of one or more separate carpels, the dehiscence being usually along the ventral suture (Fig. 239) ; in Delphinium the carpels are single ; in aconite from 3 to 5, and in star-anise {Illicium) from 7 to 8 ; in magnolia the carpels are numerous, foiming a kind of succulent cone, and dehisce along the dorsal suture. A Galbalus is a berry-like fruit, formed by the coalescence of fleshy, open scales, as in juniper (Fig. 75). Hesperidium. — The fleshy, indehiscent, superior fruit of citrus, as lemon and orange, is known as a hesperidium. The pericarp is more or less coriaceous, and from the inner walls secretion hairs develop, which contain sugar and an acid cell-sap, these consti- tuting the fleshy portion in which the seeds are embedded. A Legume is an elongated, monocarpellary, usually dry, dehiscent fruit, in which dehiscence takes place along both sutures, the carpel thus dividing into two halves, or valves, as in the garden pea (Pisiini) and other members of the Leguminosic ( h ig. 231). In some cases legumes are jointed or articulated and indehiscent, breaking up at maturity into a number of parts which are dis- persed in much the same manner as samara-fruits, as in Mciiwmia. 420 A TEXT-BOOK OF BOTANY. Legumes may be not only indehiscent but fleshy, as in Cassia fistula. A Nut is an achene-like fruit, the pericarp of which is more or less indurated. Nuts are sometimes subtended (as in acorns) or enclosed (as in chestnuts) by a kind of involucre, forming what is technically known as a cupule ; and a fruit consisting of a nut and cupule is known as a Glans. The achene-like fruit of the Labiatae is spoken of as a Nutlet. A Pepo is an inferior berry, in which the placentas have become developed into succulent layers, as in the watermelon, cucumber, and colocynth. A Pod is a general term used to designate all dry, dehiscent, apocarpous, or syncarpous fruits, as capsules, follicles, and legumes. A Pome is an indehiscent, half-inferior, fleshy, syncarpous fruit, as in the apple. The carpels constitute the core, and the fleshy part is developed from the torus. A Samara is a winged, achene-like fruit. The winged ap- pendage may be at the apex, as in white ash, or around the edge, as in elm. Two samaras may be united into one fruit, which is called a " double samara," as in maple. A Silique is a narrow, elongated, 2-valved capsule which is separated by the formation of a false dissepiment into 2 locules, as in the Cruciferse (Fig. 236, A). A Sorosis is a fleshy fruit resulting from the aggregation of the carpels of several flowers, as in mulberry (Fig. 236, H) and pineapple. A Strobile or cone is a scaly fruit, at the base of each scale of which there is either a seed, as in the Pinacece, or an achene-like body, as in hop. A Syconium consists of a succulent hollow torus, which en- closes a number of achene-like bodies, as in the fig (Ficus). An Utricle is an inferior achene with a thin and loose pericarp, as in Cheno podium. Classification of Fruits. — ]\Iore or less artificial classifications of fruits have been made. They may be grouped either according to structure or according to their manner of protection or dispersal, the following classification being based on the structure : MORPHOLOGY OF HIGHER PLANTS. 421 From a number of flowers. Dry. a. Indehiscent , 'A. With a compound pistil. From a single flower Fleshy , B. With a simple pistil. b. Dehiscent. . . . . j Dry a. Indehiscent . . . {Fleshy . . \ Drupe b. Dehiscent | Dry Strobile or Cone Sorosis Syconiura Achene Caryopsic Cremocarp Nut Samara Utricle Berry Drupe Et?3rio Hcrperidium Pepo Pome fCapsule 1 Follicle JFoUicle , Legume THE INNER STRUCTURE OF FRUITS. The inner structure of fruits is quite variable and it is difficult to treat of this in a general way. In the simplest fruits there are three distinct layers, as in the capsule of cardamom, in which there is an outer epidermis of isodiametric or polygonal cells, an inner epidermis of more or less obliterated and elongated cells, between which is a thin-walled parenchyma traversed by a number of fibrovascular bundles. In some cases the other epidermis contains numerous stomata, as in poppy capsules, or is developed into hairs and other out- growths or appendages, as in anise, arnica, sumach (Fig. 148), and raspberry (Fig. 243). The inner epidermis may also contain stomata, as in the poppy, or be developed into hairs, as in vanilla and orange, or more or less obliterated, as in achene-like fruits, or modified to sclerenchy- matous elements, as in drupes. 422 A TEXT-BOOK OF BOTANY. The middle layer, which is composed of parenchyma, may con- tain protoplasm, starch, sugars, calcium oxalate, coloring princi- ples, alkaloids and other principles, and it may also have oil-secre- tion cells, as in cubeb and pepper, or oil-secretion canals, as in orange (Fig. 121) and the fruits of the Umbellifer^e, in the latter Fig. 246. Rhamnus catharticus. A. cross-section through nail of the pericarp. E, epi- carp; F, sarcocarp; H, endocarp; e, epidermis; o, calcium oxalate in cells of hypodennis; p parenchyma; h, secretion cells containing a substance which is insoluble in alcohol or chlora solutions, soluble in solutions of potassium hydroxide, and colored reddish brown or gree& ish with ferric chloride solutions; c, calcium oxalate cells of endocarp; w, sclerotic cells; t, stereome cells. B, cross-section of entire fruit, showing one seed; E, F. H, g, f, w, as in A; S, seed-coat; S^, outer wall of seed-coat; End, endosperm; c, cotyledons; g, vascular bundle. C, cross-section of a seed: S^ S2, S^ different layers of the seed-coat; R, vascular bundle of raphe; t, position of vessels of mestome strand; g, mestome strand; Rf, cleft in which raphe is situated; End, endosperm; C cotyledons; Sv, cells with thick walls ;Sp, parenchymatous cells. — After Meyer. of which they are known as vittse (see Volume II) ; milk vessels sometimes occur, as in poppy ; a collenchymatous layer is some- times developed beneath the epidermis, as in capsicum ; in some cases sclerenchymatous cells may be present, as in pimenta and cubeb (Fig. 135) ; and in still other instances the entire pericarp may be made up of stone cells, as in the nuts. MORPHOLOGY OF HIGHER PLANTS. 423 VI. THE OUTER MORPHOLOGY OF THE SEED. The seed may be defined as the fertilized and developed ovule. The seeds of different fruits vary in number as well as in size Fig. 247. Transverse (I) and longitudinal (II) sections of oat grain (Atetta sat{t Belonging to Carolma. Carohnianus-a-um. J Carota. Carrot. The classical Latin word. Carpinus. Hornbeam. The ancient Latin name. Carum. Caraway. Gr. /cd/.'ov, Lat. carcum. Probably from Caria, in Asia Minor. Carvi or Carui. Probably an assimilated Latin genitive, as in Carui semina. Caryophyllus. Cloves. From Gr. mpvov^ nut, -|- (pv/^/ov^ a leaf ; referring to the appearance of the flower buds. Cascara Sagrada. Span. Cascara, bark, and sagrada, sacred; holy bark. Cascarilla. The bark of a Peruvian tree. Diminutive of cascara. Cassia. Senna. An ancient Greek plant name Kaaia, probably from the Hebrew gctsiah, gatsa, to cut, peel off. Castanea. The chestnut tree. The ancient Latin name, from a town in Thessaly. Catalpa. Indian bean. The aboriginal name. Cataria. Catnip. From late Latin catus, a cat. Catechu. East Indian name of extract from the acacia tree, applied natively to all astringent extracts. Cathartocarpus. Cleansing, purgative. From Gr. KaftapriKoc, cleansing, 4- KapiTog^ fruit. Caulophyllum. Blue cohosh. From Gr. KavTiog, a stem, + (pv/j.ov^ a leaf ; a stem-leaf. Ceanothus. Red root. Gr. nEavudoq, a kind of thistle. Cedron. Cedron seed. From Gr. Kt-dpov^ the fruit of the cedar. Celastrus. Staff tree. The ancient Greek name of an evergreen tree. Centaurea. Star thistle. Ancient Greek name of a plant. The plant of the Centaurs. Centifolius-a-um. Having a hundred leaves or petals. From Lat. centum, hundred, -\- folium, a leaf. Cephaelis. Ipecacuanha. From Gr. K£(t>aAT/, head, + d/.u, to collect, roll up. The flowers are collected into a capitulum. Cephalanthus. Buttonbush. From Gr. K£(pa///^ head, + di>doc^ flower. Flowers aggregated in spherical peduncled heads. Ceratonia. St. John's bread. Greek name for the carrob or locust tree. From Kepa^, a horn; alluding to the horn-shaped pods. Cerealis-e. Pertaining to grain or agriculture. From Ceres, the Latin goddess of agriculture. Cetraria. Iceland moss. From Lat. ccrtra, a shield ; in reference to the shield-shaped apothecia. Chamaenerion. Willow-herb. From Gr. ;t«/"«''' o" the ground, + vr/piov, rose-laurel. Chamomilla. Earth apple. From Gr. ;jf«y"'^S on the earth, + pf/.ov, an apple. From the apple-like odor of the flowers. BOTANICAL NOMENCLATURE. 441 Chekan. The Chilian name of Eugenia Chekan. Chelidonium. Celandine. From Gr. x^mSuv, a swallow, the flowers appearing at the same time as the swallows. Chelone. Turtlehead. Snakehead. From Gr. x^'^-^^^v, a tortoise, the corolla being shaped like the head of a reptile. Chenopodium. Goosefoot. Pigweed. The ancient . Greek name. From Xr/v, goose, + TToif , foot. Chimaphila. Pipsissewa. Bitter wintergreen. Love-in-winter. From Gr. ;t;fZ/za, winter, + ^fA^w, to love ; in allusion to the several popular names. Chionanthus. Fringe-tree. From Gr. x^^^, snow, + di^%, flower ; in refer- ence to the snow-white clusters of the flowers. Chirata or Chirayita. From the Hindoo name chiraita. Chondrodendron. From Gr. x^^^poi, 'a granule + 6iv6fjov^ a tree ; allud- ing to the warty protuberances on the bark, Chondrus. Sea moss. From Gr. xovdpo^^ cartilage; in reference to the cartilaginous fronds. Chrysanthemum. Gold-fiower. The ancient Greek name. Chrysarobinum. From Gr. ;t:P^<^oc7, gold, -f araroha, a foreign name of Gca powder. Chrysophyllum. Star apple. From Gr. xp^<^k, gold, + om Gr. A/6c, or Jupiter, -h ui-Hog, flower. Dicentra. From Gr. d/f, twice , -\- Ktvrpov^ a spur. Dictamnus. Dittany. The classical name. From Mt. Dicte, in Crete, on which the plant grew luxuriantly. Didymus-a-um. Twin, found in pairs. Gr! lVt(Svf^oc, double. Diervilla. Bush honeysuckle. Named for Dr. N. Dierville, who carried it from Canada to Tournefort. Digitalis. Foxglove. Lat. digitalis, of or belonging to the finger; alluding to the finger-shaped corollas. 444 A TEXT-BOOK OF BOTANY. Dioicus-a-um. Unisexual. The two sexes on different plants. Gr. d/-, 6ig^ twice, -jr oiKog^ a house. Dioscorea. Yam. Dedicated to the Greek naturalist, Dioscorides. Diospyros. Persimmon. From Gr. A/df, of Jupiter, -f Trvpdf, grain. Diphyllus-a-um. Having two leaves. Gr. di-^ f5/V, twice, + ///za, a gift, benefit. Dorstenia. Contrayerva. Named for T. Dorsten, German botanist, six-* teenth century. Drosera. Sundew. From Gr. ('i/joaefjog^ dewy. The glands of the leaves exude drops of a clear glutinous fluid, which glitter like dewdrops. Dryopteris. Greek name of a fern growing on oaks. From Suvg^ oak, + iT-epig, a fern. Dulcamara. Bittersweet. From Lat. diilcis, sweet, + amanis, bitter. Dulcis-e. Sweet. Dysentericus-a-um. Pertaining to dysentery, dysenteric. Gr. SvaevrepiKSg, afflicted with dysentery. Ebenaceae. Ebony family. From Gr. kjievog^ Lat. ehenns, ebony. Ecballium. Squirting cucumber^ From Gr. Ik^ out of, -\- /3d/lAw, to throw. Elasticus-a-um. Elastic, gummy. Probably formed from Gr.f/ai^j^tj, to drive. Elaterium. Classic name for a medicine prepared from the juice of the wild cucumber. From Gr. klavvu^ to drive away. Eleocharis. Spike rush. From Gr. eAog^ a marsh, + x^P^^, grace ; being marsh plants. Elettaria. Cardamom. From clettari, native name of plant in Malabar. Eleuteria. From Eleuthera, one of the Bahama Islands. Epigaea. Ground laurel. Trailing arbutus. From Gr. irr/, upon, -|- >//, earth, in reference to its trailing growth. Equisetacese. Horsetail family. Ancient Latin name equiscrtum (equi- seta), the plant horsetail. Equisetum. Horsetail. Ancient Latin name. Derived from equus, horse, + scpta (seta), a bristle. Erectus-a-um. Upright, elevated, lofty. Ergota. Ergot. From French ergot, a spur. Ericaceae. Heath family. From Gr. IpetKij^ heath, heather. Erigeron. Fleabane. Ancient Greek name of a groundsel, probably Senecio vulgaris. From 7/p<, early, -f- yipui>^ old man, from the hoary appearance of some vernal species. Eriodictyon. From Gr. epiov^ wool, + dlnTvov^ a net ; in allusion to the woolly, net-veined leaves. BOTANICAL NOME.XCLATURE. 445 Erysimum. Treacle mustard. The Greek name 01 the hcduc mustard; from epi'o)^ to draw. Erythroxylon. From Gr. ipvHpdr^ red, + ^hhiv^ wood; referring to the color of the trees or shrubs. Esculentus-a-um. Good to eat, edible, esculent. Eucalyptus. From Gr. ev, well, + Kalvirrd^^ covered; from the conical covering of the buds, which falls off at anthesis. Eugenia. Clove-tree. Named in honor of Prince Eugene of Savf)y. Euonymus. Spindle tree. Ancient classical name for a shrub. From Gr. fj\ well, -f- Sfo/za, name. Eupatorium. Thoroughwort. Dedicated to Eupator, king of Pontus. who is said to have used one of the specie, in medicine. Euphorbia. Spurge. Gr. ev(p6p[3tov, name of an African plant. Named for Euphorbus, physician to king Juba. Europaeus-a-um, Belonging to Europe. Excelsus-a-um. Lofty, high, surpassing.' Exogonium. From Gr. e^w, outside, + ydvoc, offspring; in allusion to the exserted stamens and pistils. Fagus. Beech. The ancient Latin name, from Gr. mytir^ to eat; in allusion to the esculent nuts. Compare mjyor^, a kind of oak bearing esculent acorn. Fagopyrum. Buckwheat. From Lat. fagus, beech, -f Gr. nvpor, wheat; from the resemblance of the grain to the beech-nut. Farfara. Colt's-foot. Feminine form of farfariis. the ancient Latin name. Farinosus-a-um. Pertaining to meal, mealy; Lat. farina, meal. Fastigiatus-a-uni. High, pointed, tapering; with reference to the shape of the fruit. From Lat. fastigiuin, the top of a gable, summit. Fertilis-e. Fruitful, fertile. Ferula. Asafcetida. Latin name for the plant fennel-giant. From fcrio, to strike. Ficus. The ancient Latin name for fig. Filix-mas. Male fern. Lat. Filix, fern. Mas, male. In reference to its asexual fructification. Fistula. Reed, pipe, cane; from the appearance of the long, slender fruit. Foeniculum. Fennel. The classical Latin name. Diminutive of farniim, hay. Foetidus-a-um. Fetid, stinking. From Lat. fcctor, an offensive smell. Fragaria. Strawberry. Lat. fraga, strawberries. From fragro, to emit fragrance. Fragrans. Fragrant, sweet-scented. Pres. partic. of fragro, to emit fra- grance. Frangula. Buckthorn. From Lat. frango, to break ; in allusion to the brittle stems. Frasera. American Calumba. Named for John Eraser, an English botani- cal collector of the eighteenth century. 446 A TEXT-BOOK OF BOTANY. Fraseri. Of Fraser. Latinized genitive. Fraxinus. Ash. The classical Latin name. Perhaps from Gr. (t>pdaGO)^ to hedge in. Fulvus-a-um. Yellow, tawny. Fumaria. Fumitory. From Lat. fumus, smoke. Probably from the nitrous odor of the fresh roots. Galeopsis. Hemp nettle. Gr. ya/umpt^^ a kind of dead nettle. Galium. Bedstraw. Cleavers. Ancient Greek name of a plant. Perhaps from yd?^^ milk, which is coagulated by some species. Galla. Nutgall. Ancient Latin word for oak-apple, gall-nut. Gallicus-a-um. Belonging to Gaul, now France. Garcinia. Mangosteen. Named for Laurent Garcin, French botanist of the early part of th? eighteenth century. Gardenia. Cape Jasmine. Named after the author, Alexander Garden of South Carolina (1757-1829). Gaultheria. Aromatic wintergreen. Named for Dr. Gaulthier, of Quebec, a court physician about the middle of the eighteenth century. . Gaylussacia. Huckleberry. Named for the French chemist, Gay-Lussac. Gelsemium. Yellow Jasmine. From gelsomino, the Italian name of Jas- mine. Genista. Woad-waxen. Whin. From the Celtic gen, a bush. Gentiana. Gentian. The ancient classical name. From Gentius, king of Illyria, who according to Pliny discovered the medicinal property of the plant. Geranium. Cranesbill. The Greek name. From yepavo^, a crane. The long fruit-bearing beak was thought to resemble the bill of the crane. Geum. Avens. Latin name of plant, found by Pliny. Gigartina. Sea moss. From Gr. yiynpmv^ a grape stone. From the resem- blance of the fruit bodies (cystocarps), which appear as elevated tubercles on the frond or thallus. Githago. Corn-cockle. Provincial Eng. and Welsh Gith. Glaber-bra-brum. Smooth, hairless; referring to the leaves. GlanduHfer-a-um. Gland-bearing. Lat. glandula, gland, -j- fcro, to bea*r. Glandulosus-a-um. Full of glands, glandulous. Glaucium. Horned poppy. From Gr. ylavKoq, glaucous. From the glau- cous foliage. Globulus. Latin diminutive of globus; a little ball, globular; referring to the button-like form of the fruit. 'Glutinosus-a-um. Glutinous, viscous; referring to the resinous leaves and stems. From Lat. gluten, glue. Glycyrrhiza. Liquorice. From Gr. ylvKv^^ sweet, + p/C«, root ; referring to the taste of the root. Gnaphalium. Cudweed. Everlasting. Ancient Greek name of a downy plant. Probably allied with KvcKDallov, a lock of wool. Gossypium. Cotton. From Lat. gossypion, the cotton-tree. BOTANICAL NOMENCLATURE. 447 Gouania. Chew-stick. Gramineae. Grass family. From Lat. gramen, grass. Granatum. Pomegranate. The ancient Latin name. Gratiola. Hedge hyssop. From Lat. gratia, favor; because of its supposed medicinal virtue. Graveolens. Strong-smelling. Lat. gravis, strong. + olco, to emit a smell. Grindelia. Gum-plant. Tar-weed. Named for Prof. D. H. Grindel, a Russian botanist, who died in 1836. . Guaiacum. Guaiac. From Span, guayaco, the native Haytiaii name of the plant. Guarana. Portuguese name formed from the native Brazilian name. Gummifer-a-um. Gum-producing. From Lat. gumtni, gum, -f fcro, to bear. Guttifer-a-um. Gurri-exuding. From Lat. gutta, a drop, -f fcro, to bear. Gymnocladus. Kentucky coffee-tree. From Gr. yvfiv6^^ naked, + K/nfSor^ a branch, the branches being for long periods destitute of spray. Gypsophila. From Gr. yvfpo(;^ chalk, gypsum, -f- (pileu, to love. Habenaria. Fringed orchis. From Latin habena, a thong or rein. Haematoxylon. From Gr. a///a, blood, -f- ^v7.ov^ wood ; relating to the color of the heart wood. Hagenia. Cusso. Named after Dr. K. G. Hagen, German physician and apothecary (i 749-1829). Hamamelis. Witch-hazel. Ancient Greek name of a tree with fruit like a pear {firjXi^). Of doubtful application, as the fruit is a woody capsule. Hanburii. Latinized genitive from Hanbury, an eminent English pharma- cognosist and traveller. Hedeoma. Pennyroyal. From Gr. ydioafioc, mint. From r/rlrc, sweet. + 6(7//7, scent. Hedera. Ivy. The classical Latin name. Helenium. Sneeze-weed. Ancient Greek name of a plant, said to be named after Helenus, son of Priam. Helianthemum. Rockrose. From Gr. y'/.m^, the sun, -f hvUffinv^ flower. . The large flowers open only once, in sunshine. Helianthus. Sunflower. From Gr. jy^/oc, the sun. + hvHnc^ a flower. Heliotropium. Heliotrope. Turnsole. The ancient Greek name. From ijlmq, the sun, -f rpotrjy, a turn ; alluding to the flowering at the summer solstice. Helleborus. Hellebore. The ancient classical name. Hepatica. Liver-leaf. From Gr. ^irauKo^, belonging to the liver. The leaves were thought to resemble the liver in shape. Herbaceus-a-um. Herbaceous, grassy. From Lat. herba, grass, herbage. Hesperis. Rocket. Greek name for evening flower. From eaTrqm, even- ing; alluding to the evening fragrance. Heuchera. Alum root. Named for Prof. J. H. Heuchcr. who died in 1747. Hevea. Brazilian rubber tree. From vernacular name hcve. 448 A TEXT-BOOK OF BOTANY. Hibiscus. Rose mallow. The ancient clac^ical name. Hierochloe. Holy grass. From Gr. lepog, sacred, + ;r^o;/, grass. Sweet- scented grasses strewn before church doors on saints' days. Hippocastanum. Horsechestnut. From Gr. iTriroc, horse, + Kdarnvov^ chestnut. Hirsutus-a-um. Hirsute, rough, hairy. Hispidus-a-um. Rough, shaggy, bristly. Hordeum. Barley. The ancient Latin name. Houstonia. Bluets. Named for Dr. William Houston, an English botanist* Humulus. Hop. Name of uncertain origin. Perhaps from Lat. humus, ground, alluding to the fact that the plant creeps on the ground unless supported. Hydrangea. From Gr. v6oip^ water, + ayyelov, a vessel ; from the shape of the capsule. Hydrastis. Golden seal. Orange root. From Gr. vfiup^ water, + i^pao^^ to act. accomplish. Probably with reference to the active properties of the juice. Hydropiper. Smartweed. Water pepper. Gr. v6cop^ water, -f pipcr, pepper. Hymenocallis. Spider lily. From Gr. vnijv^ membrane, -\- kqaao^^ beauty ; alluding to the crown. Hyoscyamus. Henbane. The ancient Greek and Latin name. From Gr. vf J a hog. -f- Kvafio^, a bean ; said to be poisonous to swine. Hypericum. St. John's-wort. The ancient Greek name. Probably from {■TO, under, -j- kpeiKTj^ heather. Icthyomethia. Jamaica dogwood. From Gr. /;i;^i'c, a fish, + //Z^;;, strong drink, intoxicant. Idaeus. From Gr. ^Idaloq, pertaining to Mt. Ida, near Troy, where the raspberry once flourished. Ilex. Holly. The ancient Latin name for the holm oak or holly oak. Illicium. Star anise. A Latin word meaning an allurement; alluding to the odor and attractive appearance. Impatiens. Touch-me-not. A Latin word meaning " that cannot bear or suffer," from in, not, + patiens, enduring ; from the sudden bursting of the pods when touched. Indicus-a-um. Pertaining to India. Inflatus-a-um. Inflated, swollen, puffed up. Inula. Elecampane. The ancient Latin name. Ipecacuanha. Ipecac. Portuguese name from Brazilian ipc-kaa-guena; properly a creeping plant that causes vomiting, Ipomoea. Morning glory. From Gr. Ii/', Ittoc, a worm, + bfioiog, like ; allud- ing to the twining stems. Iris. Fleur-de-lis. Blue flag. From Gr. Ipi^^ the rainbow. Islandicus-a-um. Belonging to Iceland. Isoetes. Quillwort. Ancient name used by Pliny, probably for a house- leek or evergreen. BOTANICAL NOMENCLATURE. 449 Iva. Marsh elder. Name of unknown derivation. Ixina. From native Ixine, at Cumana, Venezuela, where Loefling discov- ered the plant in 1754. Jaborandi, Native name of a South American rutaceous shrub. Jalapa. So called from Jalapa, a town in Mexico, whence it was first obtained. Jateorrhiza. Calumba. From Gr. IdTEipa, healing, + pi^a, root ; a healing root. Jeffersonia. Twinleaf. Named in honor of Thomas Jefferson. Juglans. Walnut. Name contracted from Jovis glans, nut or acorn of Jupiter. Juncus, Rush. Bog rush. Ancient Latin name; from jitngo, to join, the stems being used for bands. Juniperus. Juniper. The classical Latin name ; probably from juvenis, young, -|- pario, to produce. Youth-producing ; in allusion to its ever- green appearance. Kalmia. Sheep laurel. Named for Peter Kalm, pupil of Linnaeus. Kamala. Hindoo name of the dusty hairs of the capsules of Mallotus Philippinensis, used as an orange dye for silks. Kino. East Indian name of the dried juice of Pterocarpus Marsupium. Krameria. Rhatany. Named for Drs. J. G. H. and W. H. Kramer, Ger- man botanists of the eighteenth century. Kuhnia. False boneset. Named for Dr. Adam Kuhn, of Philadelphia, who carried the living plant to Linnaeus. Kuhnistera. Prairie clover. Named from its resemblance to Kuhnia. Labiatae. Mint family. From Lat. labium, lip; referring to the irregular corolla. Lacinaria. Blazing star. From Lat. lacinia, the lappet or flap of a gar- ment ; hence fringed, from the appearance of the flower heads. Laciniatus-a-um. Slashed, having a fringed border. Lat. lacinia, flap, lappet. Lactuca. Lettuce. The ancient Latin name; from lac, milk; referring to the milky juice. Lactucarium. The inspissated juice of the lettuce (lactuca). Lamium. Dead nettle. From Gr. Aatfj.6^^ throat; alluding to the ringent corolla, Lanceolatus-a-um. Armed with little lance or point, lanceolate. From Lat. lanccola, a small lance. Langsdorffii. Named after M. Langsdorff, Russian consul at Rio, 1829, from whom Desfontaines received his specimens. Laportea. Wood nettle. Named for Frangois L. de Laporte, Count of Castlenan, an entomologist of the nineteenth century. LapT'P.^ Burdock. The ancient Latin word for burr. Laterifolius-a-um. Growing by the side of the leaf at its base, as a laterifolius flower. Lat. latus, side, + folium, leaf. 29 450 A TEXT-BOOK OF BOTANY. Lathyrus. Vetchling. Everlasting pea. Ancient name of a plant of Theophrastus. Lauraceae. Laurel family. From Lat. laurus, laurel tree. Lavandula. Lavender. From Lat. lavo, to wash; alluding to the use made of its distilled water. Lawsonia. Henna plant. Named for Dr. John Lawson, who lived in the eighteenth century. Ledum. Labrador tea. Ancient Greek name of an Oriental shrub. Leguminosae. Pulse family. From Lat. legumen, pulse. Lemnacese. Duckweed family. From Gr. Atuva^ a water plant. Lens. Lentil. The ancient Latin name. Lentiscus. Classical Latin name for the mastic-tree. Lentus-a-um. Pliant, flexible. Leonurus. Motherwort. From Gr. Pitwi', a lion, + ovpd^ a tail. Lepidium. Peppergrass. Classical name of a cress. Also meaning a little scale; in allusion to the fruit. Leptandra. Culver's root. From Gr. Xen-rof, slender, -f avr^p, av6p6q, man; referring to the slender stamens. Leucadendron. From Gr. "KevKoq^ white, + 6h6pov^ a tree. Levisticum. Lovage. Name said to be a corruption of ligusticum. Ligusticum. Lovage. The ancient Latin name. Derived from Liguria, an Italian province where the plant abounded. Ligustrum. Privet. The ancient Latin name. Liliacese. Lily family. From Lat. lilium (Gr. Aeipiov), a lily. Limonium. Sea lavender. The ancient Greek name ; probably from Xei/uuv. a meadow. Limonium. Lemon. Ital. limone, from Arabic laimun. Linaceae. Flax family. From Lat. Ihnim (Gr. livov), flax, linen, thread. Lippia. Fog-fruit. Named for Agostino Lippi, Italian naturalist. Liquidambar. Sweet gum tree. From Lat. liquidus, fluid, -f Arabic ambar, amber ; alluding to the color and fragrance of the exudation. Liriodendron. Tulip tree. From Gr. Isipiov, lily, flower, -f- devSpov^ a tree. Lithospermum. Gromwell. Puccoon. The ancient Greek name. From Wog, stone, + anepua, seed ; alluding to the hard nutlets. Lobeliaceae. Lobelia family. From lobelia. Named after Matthias de rObel, an early Flemish botanist. Loganiaceae. Logania family. Named after J. Logan, a distinguished botanist. Lonicera. Honeysuckle. Named for Adam Lonitzer, German botanist, who died in 1586, Loranthaceae. Mistletoe family. From Gr. 2w/9ov, a thong, + avdog^ a flower. Lotus. Bird's-foot trefoil. An ancient Greek plant name. Lunaria. Moonwort. From Lat. luna, the moon ; alluding to the silver, septum of the fruit. BOTANICAL NOMENCLATURE. 451 Lupinus. Lupine. Sun-dial. Ancient Latin name of a plant. From lupus. a wolf; because these plants were thought to devour the fertility of the soil. Lupulus. Diminutive of Lat. lupus, wolf; wolfish, because it chokes the shrubbery on which it climbs. Lusitanicus-a-um. Pertaining to Lusitania, the western part of Spain. Luteus-a-um. Of or belonging to the yellow- weed (lutcum) ; hence golden yellow, flame-colored. Lychnis. Campion. Ancient Greek name for a plant with flame-colored flower. From U^vug, a light or lamp. Lycopodiaceae. Club-moss family. From Lycopodium, club moss. Lycopodium. Club-moss. From Gr. Tlvko^^ a wolf, + ^o/f, a foot; in reference to the appearance of the shoots. Lycopus. Bugleweed, Water horehound. From Gr. /,W, a wolf, -f noix, a foot ; from a fancied likeness in the leaves. Lythrum. Loosestrife. From Gr. ?.v8pov, blood; perhaps because of its styptic properties. Macis. Mace. From Gr. /ndKep^ an Indian spice. Madura. Osage orange. Named for William Maclure, an early American geologist. Maculatus-a-um. Spotted, mottled. From Lat. macula, a spot. Magnolia. Named for Pierre Magnol, professor of botany at Montpellier, France, during the early seventeenth century. Majalis. Emasculated. From Latin majalis, a barren hog. Majorana. Marjoram. Old Eng. majoran, late Latin majoraca, classical Latin amaracu^. Major-US. Larger, greater. Comparative of magnus, large. Mallotus. Kamala. From Gr. //aAAwrof woolly, fleecy; the young branches, leaves and capsules being covered with fine hair or wool. Malvaceae. Mallow family. From Lat. malva, mallow. Mamillosus-a-um. Filled with papillae or " little breasts." From Lat. mamiJla, little breast, in allusion to the stalked cystocarps. Manna. The dried exudation of Fraxinus Ornus. Gr. fidi'va, a grain, from Hebrew man, gift. Marginalis-e. Marginal, belonging to the margin. From Lat. maryo, margin, edge; with reference to the marginal position of the sori. Mariana. Carduus. Milk thistle, Virgin Mary's thistle, named from Maria, Latin name for Mary, Marilandicus-a-um. Pertaining to Maryland. Maritimus-a-um. Belonging to the sea. From Lat. marc, the sea. Marmelos. Bengal quince. From Portuguese marmelo, quince. Marrubium. Horehound. Latin classical name, derived from the Hebrew marroh, bitter; 'a bitter juice. Marsilea. Named for Aloysius Marsili, an early Italian naturalist. Marsupium. A pouch, bag. Gr. fiapav-mov; referring to the shape of the fruit. 452 A TEXT-BOOK OF BOTANY. Mastic. Gr. ^aoTixt], from naodofiai^ to chew. Used in the East as a chewing gum. Matico. Dried leaves of Piper angustifolinm. Said to have been named from a Spanish soldier, who applied the green plant to a wound and stopped the bleeding. Matrican-ia. Wild chamomile. From Lat, matrix, the womb ; in allusion to its supposed effect on that organ. Medicus-a-um. Medical, curative. Melaleuca. Cajaputi. From Gr. /ucAaf, black, -f- Aew<5f, white; the bark of the trunk being black, that of the branches white. Melilotus. Sweet clover. From Gr. fieM^ honey, + Awrof, a kind of clover. Melissa. Balrp. From Gr. fxkltaca^ a bee; the flowers yielding an abund- ance of honey. Menispermum. Moonseed. From Gr. /^w, crescent, + onipiia, seed ; in reference to the crescent-shaped seeds. Mentha. Mint. The ancient Latin name. From Gr. fiivd;/^ mint. Menyanthes. Buckbean. Probably from Gr. /^/>, month, -j- di^Oog^ a flower. Perhaps because it blooms for about a month. Mercurialis. Mercury. Ancient Latin name of a plant ; meaning belong- ing to Mercury, the messenger of the gods. Methysticum. Kava-kava. Gr. fieBvcTiKog^ intoxicating; from fxedv^ wine. Meum. Spignel. Bearwort. The ancient Greek name-.(//^oi»). Mezereum. French mczcrcon, from Persian maj:riyuu. Microcarpus-a-um. Having small fruit. From Gr. ntupog^ small, -{- Kap-og^ fruit. Mikania. Climbing hempwood. Named for J. G. Mikan, professor in the University of Prague, who died in 1814. Milaceus-a-um. Of or pertaining to millet, Lat. milium, ^nillet. Millefolium. Yarrow. The ancient Latin name ; from mille, thousand, -}- folium, leaf. Mitchella. Partridge berry. Named for Dr. John Mitchell, a botanist of Virginia, eighteenth century. Mitella. Mitrewort. Bishop's cap. Diminutive of Lat. mitra, a cap; alluding to the form of the young pod. Mollis-e. Pliant, soft, mild. Monarda. Horse mint. Named for Nicholas Monardes, Spanish botanist and author of the sixteenth century. Monniera. Hedge hyssop. Named for Prof, L. Guillaume le Monnier, a French botanist of the eighteenth century. Monotropa. Indian pipe. From Gr. fiovog^ one, -|- rpoTr//, a turn ; the summit of the stem being turned to one side. Montanus-a-um. Belonging to the mountain, mountainous. Morus. Mulberry. Ancient Latin name for the mulbei;ry tree. Mucuna.. Cowhage. From the vernacular Brazilian name. BOTANICAL NOMENCLATURE. 433 Myosotis. Forget-me-not. The ancient classical name. From Gr uir a mouse, oif, irof, the ear. From the short and soft leaves in some species. Myrica. Wax myrtle. Bayberry. From Gr. ^,,„„,, ancient name uf tl>c tamarisk. Myristica. Nutmeg. From Gr. fivpl^u, to be fragrant. Myrrha. Myrrh. Ancient classical name for the balsamic juice of the Arabian myrtle. Myrtus. Myrtle tree. The ancient classical name. Napa^a. Glade mallow. From Gr. vdm^, a woody dell. Napellus. Little turnip. Diminutive of Lat. napus, a turnip Narcissus. The ancient Greek name. From mpx,, numbness, because of Its narcotic properties. Or, according to others, from Narcissus a youth, who according to a myth was changed into this flower Nardus. Spikenard. The ancient Greek name. Nectandra. Bebeeru. Pichury beans. From Gr. .^..„. „cctar, + .„.;}„ man, nectar stamen. * Nelumbo. Sacred bean. Lotus lily. From vernacular, Ceylon. Nepeta. Catnip. Cat mint. The ancient Latin name. • Neslia. Ball mustard. Named for J. A. N. de Nesle. French botanist Nicotiana. Tobacco. Named for Jean Nicot, a French diplomat, who was thought to have introduced tobacco into Europe (1530-1600) Nigella. ^ Fennel flower. Diminutive of Lat. nigcr, black, from the color of tHe seeds. Niger-gra-grum. Black, dark. Nobilis-e. Famous, noted, well-born. Nux-vomica. Lat. nux, a nut, and vomo, to vomit. Nymphaea. Yellow pond lily. Ancient Greek name for the water lily. which was dedicated to the water nymphs. Nyssa. Tupelo. Pepperidge. The Latin name of a water nymph, nurse of Bacchus ; because the original species of the plant grows in water. Obtusifolius-a-um. Having leaves "blunted or rounded at the end. Lat. obfusHs, blunted, + folium, leaf. Occidentalis-e. Occidental. Western. Odontorhizon. Crawley-root. From Gr. 66m'c, a tooth. + pfCn, a root. Odoratus-a-um. Emitting a smell, especially sweet-smelling, fragrant. CEnothera. Evening primrose. An ancient Greek name of a plant. Officinalis-e. Pertaining to the shop. From Lat. oflicina, a workshop. Oleaceae. Olive family. From Lat. olca. olive tree. Oleum. Gr. Diaiov, olive oil ; hence oil. Onoclea. Sensitive fern. Ancient Greek name of a plant. Operculina. Turpeth root. Probably from Lat. operculum, a covering. Opium. Gr. hTTiov^ poppy juice. 454 A TEXT-BOOK OF BOTANY. Opulus. Ancient Latin name of a kind of maple. Opuntia. Prickly pear. Ancient Greek name of a plant, perhaps from ^Ot^ovq^ a town in Locris. Orientalis-e. Pertaining to the Orient or East. Origanum. Wild marjoram. The ancient Greek name. Probably from opof, mountain, 4" yai'of, brightness, joy. Ornus. Wild mountain ash. The classical Latin word. Perhaps from Gr. bpo^^ mountain. Osmunda. Flowering fern. From Osmunder, Saxon name of the Celtic divinity, Thor. Ostrya. Hop hornbeam. Ironwood. The ancient classical name. Oxalis. Wood sorrel. Ancient classical name ; from Gr. o^ic, sour. Oxycedrus. Prickly cedar. Ancient Greek name ; from b^vq^ sharp, + KedpoQ^ cedar. Cedar with pointed leaves. Paeonia. Peony. The ancient Greek name. From HaMv, physician to the gods. Palmatus-a-um. Pertaining to a palm, like a palm. From Lat. palnm,3. palm. Palustris-e., Fenny, marshy, swampy. From Lat. palus, a marsh. Panax. Ginseng. Greek name of a plant. From ttoc, all, -f amr, a cure ; all-healing, panacea. Paniculatus-a-um. Having panicles. From Lat. panicula, a tuft or panicle. Panicum. Panic grass. Ancient Latin name of Italian panic grass. Papaver. Poppy. The classical Latin name. Papyrifer-a-um. Producing papyrus. Lat. papyrus, + faro, to bear. Parviflorus-a-um. Having small flowers. Lat. parvus, small, ■■-{■ Uos, a flower. Passiflora. Passion flower. Adaptation of the Latin Uos passionis, flower of passion. From a supposed resemblance of the parts of the flower to the implements of the crucifixion. Pauciflorus-a-um. Having few flowers. Lat. paucus, few, -|- flos, a flower. Paullinia. Guarana. Named for C. F. Paullini, a German botanist (1643- 1712). Pedatus-a-um, Having pedates or lobes. Lat. pcdo, to supply with feet. Peltatus-a-um. Peltate or shield-like. Lat. pelta, a shield. Pennatifolius-a-um. Feathered, winged. Lat. pennatus, winged, -f- folium, leaf. Penthorum. Ditch stonecrop. From Gr. irivre, five, + bpog^ a rule ; refer- ring to the quinary order of the flower. Pepo. Pumpkin. Melon. The ancient Latin word. Pereirse. Of Pereira. Named in honor of Jonathan Pereira, an Eng- lish pharmacologist, who visited South America (1804-1853). Perfoliatus-a-um. Perfoliate. Stem apparently passing through the leaves. Lat. per, through, + folium, leaf. BOTANICAL NOMENCLATURE. 455 Perforatus-i-um. Perforate, having holes as if pricked through. Lat. perforo, to pierce through. Persea. Avocado. Ancient name of an Egyptian tree with fruit growing on the stem. Persicaria. Lady's thumb. From Lat. persicus, a peach tree. Petroselinum. Parsley. An ancient Greek plant-name. From irhpa a rock, + geIlvov^ parsley. Phaseolus. Kidney bean. The ancient classical name. Philadelphus. Mock orange or Syringa. Ancient Greek name of a sweet flowering shrub ; applied by Linnaeus to this genus. Phillipinensis-e. Belonging to the Philippine Islands. Phlox. Greek name of a plant with flame-colored flowers. From (p/6^ a flame. Physostigma. Calabar bean. From Gr. (pma^ a bladder. + anyfja, a mark, stigma. Phytolacca. Pokeweed. From Gr. (pvrdv^ plant, -)- Ital. /area, lake color ; alluding to the coloring matter which the berries yield. Picea. Spruce. The classical Latin name of the pitch-pine. Picrasma. Quassia. From, Gr. TziKpaafioq, bitterness. Picrotoxinum. From Gr. TziKpoq^ bitter, + to^ikov, poison. Pilocarpus. Jaborandi. From Gr. ;rZAof, a hair, -|- mpiror^ fruit ; refer- ring to the shape of the fruit. Pimenta. Allspice. From Spanish pimicnta, allspice. Derived from Latin pigmentum, spice. Pimpinella. Pimpernel. Said to be formed from Lat. bipinnula, equiva- lent to bipennis, two-winged ; referring to the bipinnate leaves. Pinus. Pine. The ancient Latin name. Probably akin to pinna, a feather. Piper. Pepper. The classical Latin name. Piperitus-a-um. Peppery, pungent. Lat. piper, pepper. Pipsissewa. Chimaphila. An American Indian name. Piscipula. From Lat. piscis, fish. Pistacia. Pistachio. The ancient classical name. Planifolius-a-um. Having flat leaves. Lat. planus, flat, plane. -f /o/t«m. leaf. Plantago. Plantain. The ancient Latin name. Podophyllum. Mandrake. From Greek ttov^, foot, + v?.?.nv; referring to the foot-like leaves. Podostemon. Riverweed. From Gr. 7ro{;f, foot, + arT/ficjv^ thread, stamen ; the two stamens being apparently raised on a stalk by the side of the ovary. Polemonium. Greek valerian. An ancient Greek name of a plant. From TTolefioq^ war. Polygala. Milkwort. From Gr. TroAi-yaP.oi-, the ancient name. iro/vq, much, + yd/la, milk. 456 A TEXT-BOOK OF BOTANY. Polygamus-a-um. Having some perfect flowers and others with stamens only, or pistils only, on the same plant ; polygamous. From Gr, rro/vg much, -\- .yafiicj^ to marry, Polygonatum. Solomon's seal. Ancient Greek name of a plant. From TToXvg^ much, many, + ydiw^ yovaror^ knee; having many joints. Polygonum. Knotweed. The ancient classical name. From Gr. ttoAvc much, many, + ydvv^ knee; having many knots or joints. Polypodium. Polypody. The ancient Greek name. From tto/jV, much, many, + ^ol'f , foot ; alluding to the branching rootstock. Polyporus. Agaric. From Gr. nolv^i many, + rcdpn^^ a pore ; referring to the porous texture of the plant. Populus. Poplar. Aspen. The classical Latin name. Potentilla. Cinquefoil. Five-finger. Name is a diminutive form of Lat. potens, powerful; from the reputed medicinal powers of one of the species. Pratensis-e. Growing in meadow-land. Lat. pratiim, meadow. Precatorius-a-um. Imploring, beseeching. From Lat. prccor, to pray ; in allusion to the use of the seeds as beads in rosaries. Primula. Primrose. Cowslip. The name is a diminutive of Lat. primus, first; from the flowering of the primrose in early spring. Procumbens. Lying on the ground. From Lat. prociimbo, to incline for- ward. Prunifolius-a-um. Having leaves resembling those of the plum tree. From Lat. prunus, plurh tree, -|- folium, leaf. Prunum. Plum. Classical Latin name for the fruit. Prunus. Plum, cherry. Classical Latin name for the plum tree. Pruriens. Itching. From Lat. prurio, to itch ; in reference to the hairs, which occasion an intolerable itching. Psyllium. Flea-seed. Ancient Greek name for fleawort. Psoralea. From Gr. fupaleocj scurfy; in reference to the glandular dots on the calyx and pods. Ptelea. Hop-tree. Ancient Greek name for the elm. Pteris. Brake or Bracken. Ancient Greek name for a kind of fern. From TTTepov, a wing; alluding to the pinnate or feathery fronds. Pterocarpus. From Gr. Trrepov, a wing, -f- nap-n-og, fruit ; in allusion to the winged legumes. Puber-a-um. Downy. Pubescens. Downy, Jiairy, woolly. From Lat. pnhesco, to become downy. Pulegioides. Like fleabane. From Lat. pulegium (Gr. rpvAAmv)^ fleabane, -f -o-etdrfg, resembhng ; in allusion to the appearance and odor. Pulicaria. Fleawort. The ancient Latin name. Pulmonaria. Lungwort. From Lat. pulmonarius, beneficial to the lungs. From, its supposed curative properties. Pulsatilla. Pasque flower. From Lat. pulso, to strike, agitate; of uncertain application. BOTANICAL NOMENCLATURE. 457 Punica. Pomegranate. From Lat. punicum, pomegranate tree. • Purpureus-a-um. Purple-colored. Purshianus-a-um. Adjective formed from Purshia. Named for Fred. Pursh, a German botanist and author of Flora America: Scptcntrionalis. Pyrethrum. Pellitory. Feverfew. Ancient Greek name for a hot, spicy plant. Pyrus. Pear, Apple. Ancient Latin name for the pear tree. Quassia. Named for a negro, Quassy or Quash, who prescribed this remedy as a specific. Quebracho-bianco. From Sp. quebranfar, to break, -f IwcJia, an axe. in allusion to the hard and tough bark. Blanco, white. Quercus. Oak. The classical Latin name. Quillaja. Soap bark. From vernacular quillai, Chili. Racemosus-a-um. Having racemes or clusters. Radicans. Rooting. From Lat. radico, to take root ; alluding to the fact that the stems send out roots. Ranunculus. Crowfoot. Buttercup. The Latin name for a little frog; some species being aquatic. Raphanus, Radish. The classical name. From Gr. /m, quickly, + (pnivnum to appear; alluding to the rapid germination. Repens. Creeping. From Lat. rcpo, to creep. Reptans. Creeping. From Lat. repto, to creep. Reseda. Mignonette. From Lat. reseda, to calm, heal ; from its supposed sedative properties. Reticulatus-a-um. Reticulate, net-like. Lat. retia, a net; leaf-veins form- ing a net-work. Rhamnus. Buckthorn. The ancient classical name. Rhaponticus-a-um. Rhapontic. From Lat Rha, the Volga river, -f- ponticiis, pertaining to the Pontic or Black Sea. The rhubarb growing on the banks of the Rha. Rheum. Rhubarb. From Lat. Rha, the river Volga, on whose banks the plant grew. Rhododendron. Rose-bay. The ancient name. From Gr. /Wni , a rose. 4- Sevdpov^ a tree. Rhus. Sumach. The ancient classical name. Ribes. Currant. Gooseberry. From Arabic ribas, a plant with an acid juice. Ricinus. Castor bean. The ancient Latin name. Robinia. Locust. Named for John and Vespasian Robin, royal gardeners of Paris, seventeenth century. Robustus-a-um. Robust, strong, oaken. Lat. robiir, oak. Rosa. Rose. The ancient Latin name. Roseus-a-um. Rose-colored, rosy. Lat. rosa, a rose. Rosmarinus. Rosemary. From Lat. ros, dew, + marinus, belonging to the sea; from its maritime habitat. 458 A TEXT-BOOK OF BOTANY. Rostratus-a-um. Beaked, curved, rostrate. Lat. rostrum, a beak. Rotundifolius-a-um. Having round leaves. Latin rotundus, round, -f- folium, leaf. Ruber-ra-rum. Red, ruddy. Rubus. Bramble. Blackberry, Ancient Latin name, akin to ruber, red. Rugosus-a-um. Wrinkled, creased. Lat. ruga, a wrinkle. Rumex. Dock Sorrel. The classical Latin name. Ruta. Rue. The ancient classical name. Sabadilla. Cevadilla. From Span, ccvadilla. Probably from Lat. cibus, food, though the seeds are poisonous. Sabal. Palmetto. From vernacular, Mexico or South America. Sabina. From Lat. Sabinus, of the Sabines ; a people of Italy who used the juniper as an incense. Saccharum. The classical name for sugar. Saigonicus-a-um. Of Saigon, a city and province in southern Annam. Salix. Willow. The classical Latin name. Salvia. Sage. The ancient Latin name. From salvo, to save; because of its supposed healing qualities. Sambucus. Elder. The old Latin name, perhaps from Gr. canlivKi]^ a musi- cal instrument. Sanctus-a-um. Holy, sacred, consecrated, Sanguinaria. Bloodroot. From Lat. sanguinarius, bloody; from the color of the juice. Sanicula. Black snakeroot. Sanicle. From Lat. sano, to heal. Santalinus-a-um. Of the sandal-tree, of sandal- wood. Gr. aavTa?.ov^ the sandal-tree. Santalum. Sandal-wood. The ancient Greek name for sandal-tree. Saponaria. Soapwort. From Lat. sapo, soap; the juice formirig a lather with water. Sarracenia. Pitcher plant. Named for Dr. Michel Sarrasin, of Quebec. Sassafras. The Spanish name. Probably a modification of saxifrage, Sativus-a-um. Cultivated. Propagated by seed. Scammonia. Scammony. Classical name of a plant. Scandens. Climbing. Lat. scando, to climb. Scilla. Squill. The ancient Greek name for the medicinal squill. Scirpus. Rush. The ancient Latin name. Scolopendrium. Adder's tongue. The ancient Greek name. From aKoAonevdiia, the centipede; alluding to the sori. Scoparia. Broom-weed. From Lat scopct, a broom. Scutellaria. Skullcap. From Lat. scutclla, a dish ; alluding to the calyx. Secale. Rye. Latin name for a kind of grain. From seco, to cut. Sedum. Stonecrop. Orpine. Latin name of a houseleek. From sedeo, to sit; alluding to the manner in which the plants attach themselves to walls and rocks. Semecarpus. Cashew-nut. From Gr. o^fia, a mark, + Kapnoq, fruit. BOTANICAL NOMENCLATURE. 459 Sempervirens. Evergreen. Lat semper, always, -f vireo, to be green. Senecio. Groundsel. Ragwort. Squaw-weed. From Lat. jrnc.r, old man ; alluding to the hoariness of some species. Senega. Seneca root. From the Seneca tribe, North American Indians, who used it as a remedy for snake bites. Senegal. Name of a country and river in W. Africa. Habitat of the plant Acacia Senegal. Senna. Senna leaves. Name derived from Arabic Sana or sena. Serenoa. Saw palmetto. Named for Prof. Sereno Watson of Harvard University (1826-1892), Serotinus-a-um. Late, backward; relating to the flowers and fruit. Serpentaria. Snakeroot. The ancient Latin name. From serpens, a serpent. Serrulatus-a-um. Serrulate, notched. From Lat. serrula, a saw. Sesamum. Sesame. The classical name of the sesame. Siliqua. The classical Latin name for a pod. Silphium. Rosin weed. Ancient Greek name of some resinous plant. Simaba. Cedron. From vernacular name, Guiana. Sinapis. Mustard. The ancient Greek name was olvnTv/. The Latin had both forms, sinapis and sinapi. Sinensis-e. More commonly Chinensis. Pertaining to China. Sisymbrium. Hedge mustard. The ancient Greek name of a sweet-scented plant. Smilax. Green brier, cat brier. An ancient Greek name for the yew. and for several plants. Socotrinus-a-um. Of Socotra, an island east of Africa, Solanum. Nightshade. The ancient Latin name. Solidago. Goldenrod. From Lat. solido, to make whole, to heal; in refer- ence to its supposed healing properties. Somnifer-a-um. Sleep-producing. From Lat. somnus, sleep, -f fero, to bear, bring. Sorbilis-e. Sorbile, fit to be drunk or sipped. Lat. sorbeo, to suck. Sorbus. Mountain ash. The ancient Latin name. Sorghum. Derivation uncertain. Probably of Chinese or East Indian origin. Spicatus-a-um. Supplied with spikes, spicate. Spigelia. Pink root. Worm-grass. Named for Adrian von dcr Spiegel. Flemish botanist of the seventeenth century. Spiraea. Hardback. Meadow-sweet. The ancient Greek name. From airdpa^ a coil or twist ; from the twisting of the pods in some species. Squarrosus-a-um. Scabby, scurfy, ragged. Staphisagria. Stavesacre. From Gr. cTacpk, rai.o, to turn, change, -f- co/or, color. Verticillatus-a-um. Disposed in a whorl. Lat. vcrticiUus, diminutive of vertex, a whirl; referring to the leaves or flowers. Verus-a-um. True, genuine, original. Viburnum. Black haw. Arrow-wood. The ancient Latin name. Victorialis. Ancient Latin name of a plant. Villosus-a-um. Hairy, shaggy, villous. Vinifer-a-um. Wine-producing. Lat. znnum, wine, -f fero, to bear. Viola. Violet. Heart's ease. The ancient Latin name of the genus. Virginianus-a-um. } _^. , , . , -it- • • ,,.... >■ Of or belongmg to Virgmia. Virgmicus-a-um. J Viridiflorus-a-um. Having green flowers. Lat. viridis, green, + flos, a flower. Viridis-e. Green. Virosus-a-um. Having a bad odor, fetid. Lat. virus, an offensive smell. Vitis. Grape. The classical Latin name. Vouacapoua. Araroba tree. From vernacular name. Central America. Vulgaris-e. Common, general, ordinary. Wisteria. Named in honor of Prof. Caspar Wistar, distinguished anatomist of Philadelphia. Xanthium. Clotbur, Cocklebur. Greek name of some plant used to dye the hair. From ^av66g^\ yellow. Xanthoxylum. Prickly Ash. From Gr. ^avftdg, yellow, + f t'Aov, wood ; referring to the color of the roots. Zea. Maize. Indian corn. Ancient classical name for a kind of grain. Zeylonicus-a-um. Of or belonging to Ceylon. Zingiber. Ginger. The ancient Greek name. CHAPTER V CLASSIFICATION OF ANGIOSPERMS YIELDING ECONOMIC PRODUCTS In this chapter will be given in natural sequence a list of the principal orders of plants that yield medicinal and other economical products. While great stress will be laid upon the plants used in medicine, yet considerable attention will also be given to the other economic substances furnished by the angiosperms, as food- products, fibers, coloring principles, woods, and timbers, as well as to the plants commonly cultivated for ornamental purposes. It will be found that the number of plants useful to man is a very large one, being derived from all the important families, so that in their consideration the student will gain a rather comprehensive view of the entire group. A. CLASS MONOCOTYLEDONE^. The Monocotyledons are mainly distinguished as follows : The embryo has only one cotyledon ; the leayes are mostly scattered and parallel-veined ; the fibrovascular bundles of the stem are of the closed type, and the flowers are typically trimerous. I. ORDER PANDANALES. This order includes members which are aquatic or marsh plants, with narrow, elongated leaves and very small, imperfect and incomplete flowers in spikes or heads. The TYPHACE.E or Cat-tail family has the flowers borne in densely crowded terminal spikes, the staminate flowers being at the upper end of the spike, while the pistillate flowers which are beneath are more persistent. The SPARGANIACE^ or Bur-reed family have the flowers borne in densely globose heads, the staminate heads being rather small and near the upper part of the stalk, while the pistillate heads are larger and situated a short distance below the staminate ones (Fig. 252). 463 464 A TEXT-BOOK OF BOTANY. Fig 252 Bur-reed {Sparganium eurycarpum), a perennial plant flowering throughout the summer and growing on the borders of ponds, lakes, and rivers throughout the United States It grows to a height of 8 to 12 dm., and produces long, nbbon-like leaves. The flowers are in heads, becoming bur-like from the divergent beaks.— After Brown. CLASSIFICATION OF ANGIOSrERMS. 46; Fig. 253. Arrow-head {Sagittaria latifolia), a common marsh or aquatic plant and very widely distributed. The leaves are variable, but almost always sapittate. It produces naked scapes which are sheathed by the bases of the petioles; the white flowers arc producfd all summer. — After Troth. 30 466 A TEXT-BOOK OF BOTANY. IT. ORDER NAIADALES. This order, as with other rather primitive orders, is made up mostly of aquatic and marsh plants, the flowers frequently being spicated. The NAiADACEvE or Pond-weed family comprises such genera as Potamogeton, the common Pond-weed, and Zostera, or Eel- grass, which is extremely common in bays and estuaries in all parts of the country, and in many places its collection forms an active industry. It is used in upholstery work and as a packing material. To the ALiSMACE^ or Water-Plantain family belong Alisma, the Water-Plantain, and Sagittaria, or Arrow-head, which is a very attractive plant (Fig. 253) . Of the latter there are a large number of species which are widely distributed. III. ORDER GRAMINALES OR GLUMIFLOR^. This order is composed of the two families, grasses (Gram- inese) and sedges (Cyperaceae). a. GRAMINE^ OR GRASS FAMILY.— The plants of this family are nearly all herbs having cylindric, generally hollow culms with swollen nodes. The leaves are exactly alternate, and have long sheaths which are split or seldom closed, tubular, and nearly always with a distinct ligule. The flowers are mostly hermaphrodite and borne in spikelets with alternate floral-leaves, the spikelets themselves being borne in spicate or paniculate in- florescences. Each spikelet (Figs. 255, 256) consists of two (seldom more) empty glumes, which are the lowest floral-leaves in each spikelet ; a varied number of flowering glumes, frequently awned or toothed, are situated inside the empty glumes, and ea-ch of which subtends a short branch (the rhachilla), the latter bearing an adorsed fore leaf (the pale), which is generally two- keeled and two-toothed, enclosing two minute scales (lodicules) and the flower. The flower has mostly three stamens (there being six stamens in Oryza and Bambusa), with the anthers versa- tile, and a simple gynsecium consisting of one carpel having two styles and a plumose stigma. The ovary is unilocular with one ascending or pendulous ovule. The fruit is a grain or caryopsis. CLASSIFICATION OF AXGIOSPERMS. 467 the seed being always firmly united with the thin pericarp (except in Sporobolus, Eleusine, etc.). The embryo is situated at the base, on the outer convex surface of the seed, outside the endo- sperm. On germination the cotyledons remain in the seed. The endosperm contains numerous starch grains and oil, while the gluten layer around the endosperm contains proteins. The number of layers of gluten- or aleurone-containing cells varies in the different cereals. In corn, wheat, and rye it consists of but a single layer ; in oat (Fig. 247) and rice, of i or 2 layers ; while in barley it is made up of 2 to 4 layers. The Grasses comprise about 3500 species and are distributed in all parts of the world. While most of the plants are grass-like, -y— Fig. 254. Diagrams of cross-sections of monocotyledonous flowers: t, stem of plant; f, bract; s, sepals or outer circle of perianth; p, petals or inner ciicle of perianth; a, stamens; c. ovary. A, regular flower of the lily; B, irregular flower of iris. C, flower of an orchid, in which 1 is the position of the lip and 6 6 of the two staminodes. — After Warming. still some of them, as the bamboos of the Tropics, become quite tall, having woody siliceous stems and bearing many branches in the axils of the leaves. The grasses yield the cereal grains forming so large a proportion of the food of man, and forage constituting the food of many of the lower animals. The following are some of the important cereals: Wheat {Triticiun sativum and its varie- ties), corn {Zea Mays), oat (Avena sativa), rice {Ory::a satira), barley {Hordeum sativum and its varieties), rye (Secale cereale). A number of the species yield a sweet cell-sap from which cane sugar is made, of which the most important are the sugar cane {Saccharum officinarum) and sorghum {Andropogon aruudina- ceus saccharatus and other varieties). (Consult pp. 148, 156, 198.) 468 A TEXT-BOOK OF BOTANY. A large number of the grasses are used in medicine, one of which, couch-grass {Agropyron repens), is official. Agropyron repens is a common perennial grass, forming slen- der jointed rhizomes, by means of which the plant is extensively propagated : the culms vary from one to four feet in height, the spikelets are 3- to 7-flowered ; and the empty glumes, 5- to 7-nerved, acute or with an awn-like apex. Hordeiim satimiin is an annual grass with the flowers in ter- J.O.»VA*'«' Fig. 25s. Wheat (Triticum): A, zigzag axis or rachis of ear showing the notches where the spikelets were inserted; B, an entire spikelet; C, a flower with the pales; D, a flower without the pales, showing the lodicules at the base; E, glume; F, outer pale; G, inner pale; H, fruit (caryopsis) ; I, longitudinal section of fruit. — After Warming. minal cylindrical spikes resembling wheat. The spikelets are ses- sile, i-flowered, and usually in clusters of three on opposite sides of the notched rachis. The empty glumes are long and narrow, forming a kind of involucre around the spikelet. It is supposed that Hordeum sativum is a cultivated form of H. spontaneum growing in the countries between Asia Minor and other parts of Western and Southwestern Asia. Three important varieties are distinguished, depending upon the number of rows of grains in CLASSIFICATION OF ANGIOSPERMS. 469 the ear. H. sativmn distichon includes the plants having 2-ro\ve(l ears, and these are. chiefly grown in Middle Europe and England. H. sativum hcxastichon includes the plants having the grains in 6 rows, these having been cultivated since prchistoiic times and furnishes the winter barley. //. satknim vidgarc includes the plants in which the grains are in 6 irregular rows, and these are cultivated in northern temperate regions. The latter plant is cultivated in the United States and furnishes the spring or summer barley, largely used in the preparation of malt. Zea Mays (Indian Corn) is a cereal plant probably indigenous to Central Mexico. It is extensively cultivated in the United Fig 256. Diagrammatic outline of a spikelet: nY, lower glume; «^ Y, upper glume; nl, outer pale; <^ I, inner pale; 1, 1, lodicules; st, stamens; I-I, main axis; II, lateral axes or branches. — After Warming. States and other parts of the world for its grain. From a multi- ple, primary, somewhat fibrous root arise one or more erect simple culms, which are grooved on alternate sides in the successive internodes and from the nodes of which arise aerial secondary roots. The leaves are alternate and consist of 3 parts: (a) a blade, which is long, broadly-linear and tapering toward the ai)ex. the tip being pendulous; {h) a lower sheathing portion wliicli is open; and {c) a short, translucent, somewhat hairy ligule, situated between the sheath and the blade. The tiowers are monoecious, the staminate, which are arranged in a terminal pan- icle, maturing first ; the pistillate occur in axillary spikes, the axes of which constitute the corn cob. Thev are enclosed in 4/0 A TEXT-BOOK OF BOTANY. spathe-like bracts or husks, from which the long filiform styles (p. 178) protrude. The grain is somewhat ovate or triangular, flattened, pointed at the base, grooved on one side, indicating the position of the embryo, from 10 to 15 mm. long and about 10 mm. broad, more or less translucent, and varies in color in the different varieties. The constituents of the corn grain are 50 to 75 per cent, of starch ; about 10 per cent, of proteins ; 4.29 per cent, of a fixed oil; about 5 per cent, of sugar, and 1.29 per cent, of ash. There are a large number of varieties and sub-varieties of Zca Mays, some of the former being ranked as species. The follow- ing well-defined varieties may be mentioned : ( 1 ) Zea Mays everta, to which belong the pop-corns. The size of the ears and grains is about one-half or less that of the other corns ; the grains have a more or less translucent and horny endosperm, the cells of the latter containing numerous compactly arranged polygonal starch grains, which are from 7 to 10 /x in diameter and have a central rarefied area from 2 to 7 /x in diam- eter. It is owing to the structure of the starch grains that the peculiar popping of the corn grains results when they are heated. Heating the corn grains at 145° to 160° C. for from 4 to 10 min- utes causes the bursting of the starch grains, and at the same time a rupture of the cells and splitting of the pericarp into 4 parts. The white appearance of the popped grains is due to the inclusion of air in the bursted cells. During the heating the starch is con- verted into a soluble form, and this gives popped corn its nutritive value. Some of the flint and dent corns show a similar tendency to pop when heated, but it is only in those parts of the endo- sperm that are horny and the cells of which contain compactly arranged polygonal starch grains in which the rarefied area is at least from one-tenth to one-fifth the diameter of the entire grain. Pieces of the pop-corn, as well as the horny portions of some of the flint and dent corns, will pop as readily as the whole grains. (2) Zea Mays indentata yields the dent or flint corns, the grains of which have a corneous (horny) endosperm on the sides and are indented at the summit, owing to the shrinking of the cells which contain more cell-sap and less compactly arranged starch grains. The starch grains in the cells of the horny endosperm resem- CLASSIFICATIOxM OF AxXGIOSPERMS. 47] Fig. 257. Carex lurida, one of the Sedge family {CyPeracea), found throughout the summer in swamps and wet meadows in the eastern and central United States. It is a perennial grass-like herb with triangular culms, 3-ranked leaves, and with 2 to 4 spikes of flowers. The genus is a vast one of more than a thousand species, widely distributed and most abundant in the temperate zones. — After Troth. ble those of pop-corn, but the starch grains in the other cells are more or less rounded or slightly polygonal, and vary from 5 to 25 /i in diameter; the central rarefied area is either wanting or usually not more than 2 /x in diameter. (3) Zea Mays saccJiarata yields the sugar corns. While the 472 A TEXT-BOOK OF BOTANY. grains are more or less translucent and horny, they have a wrinkled or shrivelled surface. The cells of the endosperm con- tain gum-like substances and a relatively small number of nearly spherical starch grains from 4 to 10 /i. in diameter. Broom corn. (Andropogon anindinaccus vidgaris) is a plant which is cultivated for the panicles or seed heads, which are used in the manufacture of brooms. Tliis plant differs from the other species of Andropogon in that the branches of the panicles are longer, straighter, and stronger, forming a so-called *' brush." Quite a number of the grasses contain odorous principles, as Andropogon citratus, which yields lemon-grass oil; A. Schocnan- tlius, which yields gingergrass or geranium-grass oil; A. sqitar- rosus, the rhizome of which is known as Vetiver. Coumarin is found in \^anilla grass {Anthoxanthiim odoratmn) and white or Dutch clover {Hierochlcr odorata). Some species of Stipa are used in the manufacture of paper (Alfa or Esparto) in North Africa and Spain. b. CYPERACE^ OR SEDGE FAMILY.— These plants are all herbaceous, the majority being perennial (seldom annual). The rhizomes are mostly sympodial (being monopodial, however, in certain Carices), and the stems are mostly solid and triangular, without swollen nodes. The leaves are grass-like, generally arranged in three rows, and the sheath is closed, being mostly without ligules. The flowers may be hermaphrodite or unisexual, sometimes dioecious, and arranged in spikes or racemes. The perianth is wanting or only represented by 6 bristles, or by an indefinite number of hairs. The number of stamens is 3, with the anthers attached by their bases to the filament. The gynaecium consists of 2 to 3 carpels, with one style divided into 2 or 3 branches, and provided with papill?e. The fruit is a nut, whose seed is generally united with the pericarp. The embryo is small and is centrally situated at the base of the seed, being surrounded by the endosperm. On germination, the cotyledon is freed from the seed. A number of the sedges yield food products, as the rhizomes of Cyperus esculentns and Eleocharis tiiherosa, the latter of which is used in the manufacture of starch in China and India. Quite a number of species of Scirpus, Cyperus, Carex, etc., are used in CLASSIFICATION OF AXGIOSPERMS. 473 medicine. Various species of Cyperus (C. scariosus, of the East Indies, and C. pertenuis, of India) yield ethereal oils and are used in making perfumery. Cyperus Papyrus is used in medicine and also furnished the paper of the Ancients :s. IV. ORDER TRINCU'ES. In this order is included that interesting group of tropical land sub-tropical plants the palms (Palmse). They are arbores- cent, having simple unbranched trunks which are terminated by clusters of leaves, in the axils of virhich flowers are produced. The leaves are pinnate (Feather Palms) or palmate (Fan Palms) and often very large. The petiole is well developed, with an am- plexicaul, more or less fibrous sheath. The inflorescence is usually lateral, in some cases forming a large spadix with a woody, boat- shaped spathe. In comparison the individual flowers are very small. The fruit is either a berry, as in the Date palm, or a drupe, as in the Cocoa-nut palm, generally i -seeded and with a large horny or bony endosperm, as in the Date palm (p. 135) and Phytelephas macrocarpa, the latter of which yields vegetable ivory, used in the making of buttons (Fig. 258). The fruit of the saw palmetto [Serenoa (Sabal) serrulata], one of the fan palms, is official. The saw palmetto is characterized by having a creeping, branching root-stock or rhizome, one end of which rises a short distance above ground, this portion being surmounted by a dense crown of leaves. The petioles are slender and spinose on the edges ; the blade is fan-shaped and consists of a number of palmate divisions which are slightly cleft at the apex. The inflorescence is densely tomentose and shorter than the leaves. The fruit is a i -seeded drupe. The palms yield a number of useful products. The Betel-nut palm (Areca Catechu) produces a seed having medicinal proper- ties (Fig. 259). The seeds, known as ari-:ca nut, are 20 to 25 mm. long, conical, grayish-brown, with numerous spiral, reddish veins, heavy, hard, somewhat aromatic, astringent, and slightly acrid. They contain about o.i per cent, of an oily liquid alkaloid, arecoline, which chemically and in its physiological action resem- bles pelletierine ; 14 per cent, of tannin, resembling catechutannic acid; gallic acid; a red coloring principle; and 14 per cent, of a 474 A TEXT-BOOK OF BOTANY. fixed oil. They ako contain 3 other alkaloids: arecaine, arecai- dine, and guvacine, but these do not seem to give the drug its properties. Carnauba-wax is obtained from the Carnauba-palm of Brazil {Copernicia cerifera). The wax exudes from the surface of the young leaves and is obtained by boiling them with water. Dragon's Fig. 258. Vegetable Ivory, the endosperm of the seeds of a Central American palm {Phytelephas macrocarpa). The fruits are produced near the ground, are nearly globular, measuring about i meter in circumference, and weigh about 14 pounds each. They are covered with- a woody spinose wall (A), and enclose a number of drupes (B), each of which contains a single hard seed (C). The latter contains a hard, white, fine-grained endosperm (D); it is used in making small articles of turnery, as buttons, etc. — Reproduced by permis- sion of The Philadelphia Commercial Museum. BLOOD, a bright red resinous substance, is obtained from the juice of the fleshy fruit of Calamus Draco. It consists chiefly of resin, some tannin, and about 3 per cent, of benzoic acid. The Oil palm (Elo^is guineensis) of equatorial West Africa yields a drupe with an oily sarcocarp, from which, by means of pressure or boiling with water, palm oil is obtained. The Cocoa- nut palm (Cocos nucifera) yields the cocoa nut of the market, CLASSIFICATION OF AXGIOSPERMS. 475 and is probably one of the most useful palms to the natives, fur- nishing, as it does, food, clothing, utensils of all kinds, building materials, etc. The Sago-palms (Metroxylon Rumphii and M. Iceve) yield sago, which is prepared by washing out the starch from the cut stems and subsequently heating it. A tree 15 years old yields from three to four hundred kilograms of sago starch. The Date palm {Phocmx dactylifera) yields the dates of the Fig. 259. A number of Areca-nut palms (Areca Catechu) growing in Ceylon. The stems are slender, attaining a height of 25 meters or_more, with a diameter of 3 to 4 dm. and bearing a cluster of leaves at the summit. The palm is also known as the Betel-nut palm, and is extensively cultivated througho'lt tropical India. — Reproduced by permission of The Philadelphia Commercial Museum. market, and it is interesting to note that since very early times the fruits produced by the growers in the Orient have been the result of artificial or hand-pollination. V. ORDER ARALES OR SPATHIFLOR.E. This order includes two families which are markedly different in their habits: (i) The Araceas, which are rather large herbs with an inflorescence known as a spadix and consisting of a fleshy 476 A TEXT-BOOK OF BOTANY. Fig. 260. Fruits and flowers of several of the palms. A, cluster of flowering spikes of the cocoanut palm {Cocos nucifera); B, number of the young fruits of the cocoanut palm; C, cluster of the ovoid fruits of the betel-nut palm {Areca Catechu); D, compound inflorescence of drooping spikes of the kittul (kittool) palm {Caryota urens); E, large clusters of deltoid fruits of kittul palm. — Reproduced by permission of the Philadelphia Commercial Museum. The cocoanut palm yields a larger number of economic products than any other tree in the world; the fruit is edible and yields the cocoanut oil, the sap produces an alcoholic beverage, the leaves are used for making useful articles, and the wood is employed in cabinet making. The Betel-nut palm yields a number of valuable products, the most important being the seed, which is not only used to stimulate digestion, but is used in many religious cere- monies, as well as in regulating the intercourse of the more polished classes of the East. The base of the leaf stalks of the kittul palm yield a fiber which is elastic, shows considerable tenacity, and is used in the making of brushes for brewers' use. CLASSIFICATION OF ANGIOSPERMS. 477 Fig. 261. Jack-in-the-Pulpit, or Indian Turnip (Arisama triphyllum), a very common perennial herb growing in woods and thickets of the eastern and central parts of the United States and Canada, and characterized by i or. 2 leaves which are divided into 3 elliptical- ovate, pointed leaflets and a characteristip spathe of a greenish color, frequently purple- striped and curving in a broad flap over the top of the club-shaped spadix. The plant produces a turnip-shaped corm with an intensely acrid juice. — After Troth. 478 A TEXT-BOOK OF BOTANY. spike, which is subtended or enclosed by a large bract known as a spathe, as in the Calla-lily, where it is large and white, and (2) the Lemnacese or duckweed family, which is composed of minute, .y^jk w Fig. 262. Skunk Cabbage (Symplocarpus foetidus), a perennial herb producing a very thick rhizome, from which arise in the early spring the flowers crowded on a spadix sur- rounded by a large, shell-like spathe which barely rises out of the ground and is striped or spotted with purple and yellowish-green. These are followed by a cluster of ovate, cordate leaves becoming 3 to 6 dm. long. In the illustration are shown 4 of the spathes, the one at the left being cut open to show the globular or ovoid spadix, and a single leaf unfolding. — After Troth. floating, thalloid plants that develop one or more flowers on the margin or upper surface of the thallus. ARACE^. OR ARUM FAMILY.— The plants belonging to this family are perennial herbs with tuberous or fleshy rhizomes CLASSIFICATION OF ANGIOSPERMS. 479 and simple or compound leaves which are usually long-petioled. The spadix is densely flowered, the staminate flowers being above and the pistillate below on the same axis, or the plants are wholly dioecious. The perianth when present consists of 4 to 6 scale-like segments. Frequently the spadix is subtended or enclosed by a more or less showy spathe. The fruit is usually a berry, some- times a utricle. Fig. 263. Water Arum {Calla palustris), showing portion of rhizome, the broadly ovate and cordate leaves, and the inflorescence, which consists of a cylindrical spadix and an elliptical spreading spathe. A number of the plants of this family have medicinal proper- ties, and one of them yields the unofficial drug calamus. The drug is derived from sweet flag {Acorus Calamus), a plant common in swamps and along streams in the Eastern United States, and characterized by its long, narrow, linear, bilateral leaves, which are from 6 to 18 dm. in height and about 25 mm. in width. The inflorescence is a spike-like spadix having greenish-yellow flowers. Many of the Aracese possess an acrid juice. The acridity is 48o A TEXT-BOOK OF BOTANY. probably due either to saponin or an acrid volatile principle rather than to raphides of calcium oxalate. Frequently these principles are dissipated or destroyed on cooking, and the plants are then used as food, as the water arum {Calla paliistris), which on account of its acrid principles is used as a remedy for snake bites when in the fresh condition, but which on drying loses its acridity and being rich in starch is used as a food (Fig. 263). To this family also belong Jack-in-the-pulpit, or Indian turnip (Ari- sccma triphyllum) , the acrid corm of which is used in medicine (Fig. 261); SKUNK cabbage (Syrnplocarpus fcctidus), the fetid rhizome of which has medicinal properties (Fig. 262). A number of plants of the Arum family are rich in starch, as the tubers of XantJiosoma ediile of Surinam, which contain 62 per cent, of starch. VI. ORDER XYRIDEALES OR FARINOS.T.. The plants are mostly perennial herbs of tropical and sub- tropical America. The order includes a number of families, among which is Bromeliace.^, to which the pineapple (Ananas sativus) belongs. Pineapple is a native of Brazil and is now cul- tivated in warm countries of the eastern and western hemispheres. The fruit contains a proteolytic enzyme resembling trypsin and also a milk-curdling ferment. The bast fibers of the leaves are used for textile purposes. Some of the Bromeliacese are epi- phytic (air-plants), the best known member being probably the Florida mo^s {Tillandsia usneoides), which is used in upholstery (Fig. 264). The family Commelinacese is represented in the United States by Commelina or day-flower, some species of which have medic- inal properties. The roots of some tropical species contain saponin, as C. deficiens, of Brazil. The rhizomes of a number of species of Commelina ^ontain notable quantities of starch and are edible. The spiderworts (Tradescantia) common in rich soil in the United States, and the Wandering Jew (Tradescantia Zehrina) commonly cultivated as an ornamental plant, also belong to this family. To the pontederiace.^ belong several perennial aquatic or bog plants, whose leaves are usually thick or in some cases long and grass-like. The flowers are frequently arranged in Spikes subtended by leafrlike spathes (Fig. 265). CLASSIFICATION OF ANGIOSPERMS 481 A TEXT-BOOK OF BOTANY Fig 26s Pickerel Weed {Pontederia cordata), a common aquatic herb growing along the margin of' slow slreams. It is a very hardy plant occurring far north and grows best m water ten or twelve inches deep. It produces long-petioled leaves and a single stem bearmg a spike of violet-blue, ephemeral flowers.— After Troth. CLASSIFICATION OF ANGIOSPERMS. 483 Fig. 266. Small Solomon's Seal, also commonly known as true Solomon's Seal {Poly- gonalum biflorum). It is a perennial herb with lance-oblong, sessile leaves, in the axils of which are usually two nodding greenish flowers. The plant grows in moist woods or wooded hillsides, and receives its common name from the creeping knotted rhizomes, on the upper surface of which are usually one or more prominent circular scars, formed upon the decay of the aerial shoots. — After Biown. 484 A TEXT-BOOK OF BOTANY. 3| kerb wUh iVomelZ st'^^m t^l."?^'^ f"*^""" <^'"'""'"' '"^"nosa) a oer ■ ,' CLASSIFICATION OF ANGIOSPERMS. 485 VII. ORDER LILIALES OR LILIIFLOR.E. The plants of this order are mostly perennial herbs with rhi- zomes, tubers, bulbs, or fibrous roots. The leaves are parallel- veined. a. LILIACE^ OR LILY FAMILY.— The plants are tlic most typical of the Monocotyledons. They are scape-like herbs with bulbs ; the flowers are symmetrical, and the perianth is parted into 6 more or less distinct segments (Fig. 123) ; the anthers are introrse. The ovary is free, 3-locular, with a single style, and the fruit is a 3-locular, loculicidally dehiscent capsule. The Liliaceae is one of the most important families, containing about 2500 species, many of which are of great economic interest. Quite a number are cultivated on account of the beauty and fra- grance of their flowers. Among the latter are the hyacinth, lily, lily-of-the-valley, tuberose, tulip, and yucca. Of those yielding food products we have asparagus, being the young shoots of Asparagus officinalis. The edible bulbs include the onion {Allium Cepa), garlic (Allium sativum), the leek or scullion (Allium Porrum), and chives (Allium Scho^noprasum). A number of the Liliaceae are among the common wild flowers, as swamp pink (Fig. 272), bellwort (Uvularia), lily (Lilium), dog's-tooth violet (Erythronium), Star of Bethlehem (Ornithogalum), False Solo- mon's Seal (Fig. 267), True Solomon's Seal (Fig. 266), Indian Cucumber-root (Medeola), colic-root (Fig. 271), cat brier (Smilax), etc. The following plants are of medicinal interest: Veratrum viride is a plant 2 to 8 feet high, which is charac- terized by the broad, clasping, strongly plicate leaves, and by hav- ing the flowers in large terminal panicles (Fig. 268). The plant is found in sw^amps and wet woods in the United States in spring and early summer. The rhizome is upright, and it with the roots is used in medicine. The plant, including the rhizome, closely resembles the Veratrum album of Europe. Colchicum autumnale. — This is the autumnal-flowering colchi- cum, a perennial herb but a few inches high which arises from a corm and bears proportionately large lilac-colored flowers. The fruit consists of 3 follicles containing numerous seeds. The corm and seeds of this and other species of Colchicum are used in 4S6 A TEXT-BOOK OF BOTANY. Fig. 268. Flowering specimen of Verairum viride, showing the spreading, spike-like racemes and the parallel-veined leaves. CLASSIFICATION OF ANGIOSPERMS. 487 medicine. Among the species yielding large corms and extensively cultivated is Colchicutn Bunnanii (Fig. 269). Aloe species. — The stems are about a meter high and bear at the summit a cluster of thick, succulent leaves which are lance- olate and spinous-toothed (Fig. 270). The inflorescences are in long spikes which are quite showy and characteristic for the differ- ent species. Aloe Perryi, which yields the Socotrine aloes, possesses leaves with white spines and flowers that are orange-red or scarlet at the base, the stamens being unequal ; Aloe vera, which yields the Barbadoes or Curacao aloes, has leaves with yellow or reddish spines and yellow flowers in which the stamens are as long as the corolla ; Aloe ferox and some other African species, which yield Cape and Uganda aloes, have flowers in close spikes, the petals being white and marked by green lines, and the stamens much longer than the corolla. The inspissated juice is official in all the pharmacopoeias. Urginea maritima, which yields the drug squill, is character- ized by its large, onion-like bulb, from which arise ten to twenty broadly lanceolate, grayish-green leaves ; and by having the in- florescence in long spikes consisting of whitish flowers which have a distinctly purple stripe on each division of the perianth, s Canvallaria majalis or Lily-of-the-valley is a plant which is well known. It produces a raceme of delicately odorous white flow^ers and beautiful oblong leaves with prominent, parallel veins. The rhizome and roots are official. Smilax species. — The drug sarsaparilla is yielded by at least four different species of Smilax. These are mostly vines with woody or herbaceous, often prickly stems and leaves with petioles which have a pair of persistent tendril-like appendages. The flowers are small, mostly greenish, dioecious and in axillary umbels. The fruit is a globose berry. Not a great deal is known of the species which yield the drug, with the exception of Smilax medica. which yields the Mexican or Vera Cruz sarsaparilla. In Smilax medica the leaves vary from more or less cordate to auriculate- hastate; in Smilax officinalis, which yields the. native Jamaica sarsaparilla, they are ovate, as they are also in Smilax papyracea, which yields Para sarsaparilla. The Jamaica Sarsaparilla, official in the British Pharmacopoeia, is obtained from plants of Smilax 488 A TEXT-BOOK OF BOTANY. ornata growing in Costa Rica and subsequently shipped to Jamaica. Nothing is known of the plant yielding Honduras sarsaparilla, although this drug has been in use for nearly four centuries. It f IG. 269. Flowering plant of Colchicum Burmami, a form producing very large corms and extensively cultivated in Holland. is said to be derived from Smilax officinalis. The sarsaparilla plants have short rhizomes which give rise to long roots, which are the part used in medicine. A dragon's blood, resembling that derived from Calamus CLASSIFICATION OF ANGIOSPERMS. 489 Draco, is obtained from Dracccna Draco, a tree growing in the Canary Islands. Some of the trees of this species are of historic interest, as the dragon tree of Orotava, which is 46 feet in circum- ference at the base. A number of the plants of this family contain saponin, as the species of Smilax. Some contain coniferin and vanillin, as Aspar- agus oiJicinalis. Some of the group contain glucosidal principles which under the influence of ferments yield ethereal oils contain- FiG. 270. A field of Aloe plants, growing in the Riversdale District, Cape Colony. The stems are simple, with one or more clusters of leaves; the latter are from 3 to 6 dm. in length, fleshy and very thorny-prickly at the margin. — Reproduced by permission of the Philadelphia Commercial Museum. ing sulphur, as the various species of Allium. Garlic {Allium sativum) contains a glucoside, allisin, which on hydrolysis with an oxidase (allisin) forms the essential oil of garlic. A number also are quite poisonous when fresh but edible when cooked. &. AMARYLLIDACEvE OR AMARYLLUS FAMILY.— This group is of special interest because it includes the Agave or Century plant. This is a characteristic genus of plants of the hot and arid regions of North America, The best known of these 490 A TEXT-BOOK OF BOTANY. is the Century plant (Agave ajuericajia) , which is one of the most important economic plants of Mexico. The stem axis of the plant is very short and the thick, fleshy leaves form a tuft at Fig. 271. Plant of Aletris farinosa showing characteristic rosette of lanceolate leaves at the base and portion of long slender scape with numerous tubular flowers. The plant is common in dry coniferous woods in the eastern part of the United States. the summit. The leaves are lanceolate, with spinose margins, and furnished with stout terminal spines. The leaves as well as the roots contain a large amount of mucilage which retains water and CLASSIFICATION OF ANGIOSPERMS. 491 Fig. 272. Swamp Pink {Helonias biiUala) is a rather rare plant found only in certain localities, particularly in wet places, extending from southern New York to Virginia. It produces a tuberous root-stock, and the evergreen leaves are clustered near the base of a naked scape which bears in the early spring a short raceme of purplish flowers. This should not be confounded with the plant yielding the drug known as Helonias or false unicorn root, the latter being derived from Chamalirium luleum, and at one time known- as Helonias dioica. — After Troth. 492 A TEXT-BOOK OF BOTANY. thus helps to adapt the plants to these arid regions. The plants grow slowly and may flower when they are ten or twelve years old. The Agaves contain saponin and other principles of medicinal value. They yield a number of other products, as follows: Pulque, a fermented drink of the Mexicans ; Mezcal, a distilled drink resembling rum ; various fibers, as Sisal hemp, " Hene- quen " or " Sacci," etc. Other members of the Amaryllidaceae likewise find use as medicines and as foods, many of them being cultivated as ornamental plants, as Narcissus, Hymenocallis, Crinum, and Amaryllis. c. DIOSCOREACE^ OR YAM FAMILY.— The plants be- longing to this family are twining shrubs or herbs with tubers either above or below ground. The general characters of the plants are shown in the wild yam-root {Dioscorca villosa) of the United States (Fig. i8o). Several species, notably, D. Batatas, yield the yams or Chinese potatoes of commerce. Many of the species of Dioscorea, as well as other members of this family, contain active principles which, like those of the Araceae and Liliaceae, are destroyed on heating. The rhizome of Tamils communis contains saponin, and Rajania subamarata con- tains tannin. d. IRIDACE^ OR IRIS FAMILY.— The plants of this fam- ily are perennial herbs with mostly equitant (bilateral) leaves and horizontal rhizomes, or corms. The flowers are regular or irregular and with a petalloid stigma (Fig. 254, B). Iris versicolor is a flag-like plant, commonly known as the LARGER BLUE FLAG, and found abundantly in the marshes and wet meadows of the Eastern L^nited States. It is distinguished by its tall stems and sword-shaped, somewhat glaucous leaves. The flowers are violet-blue. The rhizome somewhat resembles that of calamus, but is of a dark brown color and contains 25 per cent, of acrid resins, a volatile oil, starch, and tannin. Iris -florentina, which yields the orris root of commerce (Fig. 190), is a plant cultivated in Middle and Southern Europe, and closely resembles the above-mentioned species. The rhizome con- tains a volatile oil resembling that found in violets, and is used in perfumery. Orris root is also obtained from Iris germanica and /. pallida. The violet odor is developed on keeping the rhizome a vear or two. CLASSIFICATION OF ANGIOSPERMS. 493 Crocus sativus, the orange-red stigmas of which have been used in medicine since ancient times, is an autumnal-flowering plant. The flowers are lilac-purple, somewhat like those of Colchicum, and occur at the summit of a scape rising 15 to 20 cm. above ground. The leaves are linear and rise directly from a more or less globular corm. The plant is cultivated in Spain and other parts of Europe and in the United States as well. The stigmas constitute the drug saffron (Crocus), which was formerly official, and contain a coloring principle, i part of which will impart a distinct yellow color to 100,000 parts of water. Saffron contains a yellow glucoside, crocin, which is soluble in alcohol but not in water, and is colored blue by sulphuric acid. The drug also con- tains 7.5 to 10 per cent, of a volatile oil, which appears to be derived from a coloring principle that resembles carotin ; and the bitter principle picro-crocin. e. JUNCACE^ OR RUSH FAMILY.— These are grass-like marsh plants, which are distinguished by the fact that the flowers are small, with a 6-parted glumaceous perianth, and the fruit is a loculicidally dehiscent capsule. The stems are mostly solid, slen- der, usually arise in tufts from the rhizome, and are characterized by stellate parenchyma cells, among which are large, intercellular spaces, the latter also being characteristic of the leaves. The rushes are principally found in cold and temperate regions. Several species of Juncus and Luzula have been used in medi- cine, particularly in Europe. The seeds of Lunula compestris, a common wood rush of the United States naturalized from Europe, are edible. Soft rush (Juncus effiisus) and Hard rush (/. conglomeratits) are used in Japan in the manufacture of rush matting. In Holland the rush is grown on the embankments along the coast to prevent the action of the tides. VIII. ORDER SCITAMINALES OR SCITAMINE.l!:. The plants of this order are mostly found in the Tropics and are perennial herbs with fleshy rhizomes. The leaves are large, more or less elliptical and pinnately veined. The leaf sheaths close tightly around each other and form a kind of false stem. The flowers are epigynous, unsymmetrical or zygomorphic, and fre- quently only one stamen is completely developed 494 A TEXT-BOOK OF BOTANY. a. THE ZINGIBERACE^ OR GINGER FAMILY is dis- tinguished from the other Scitaminese by the fact that the seeds have endosperm as well as perisperm. The plants are rich in volatile oils, and a number are used in medicine and perfumery. Zingiber officinale yields the official ginger (Fig. 2/^). From a creeping, fleshy, branching and laterally compressed rhizome (Fig. 187 ) arises a stem about i M. high bearing numerous lanceo- late leaves. The flowering stalk arises directly from the rhizome, terminating in a spike which bears flowers having greenish-yellow petals with violet or purple stripes. Elettaria Cardamomiim (E. repens) yields the cardamom of the several pharmacopoeias (Fig. 237). The plant has a leafy as well as floral stem which rises from a tuberous rhizome. The leaves are broadly lanceolate. The flowers are greenish-white, the labellum (consisting of two petal-like staminodes) being bluish. The fruit is a capsule, and the seeds are the part used in medicine. The so-called paradise grains are the seeds of Amomum Melegueta growing in Western Africa. They are about 3 mm. in diameter, dark brown, nearly smooth, friable, and contain a vola- tile oil. Galangal, which is used in perfumery, is the rhizome of Alpinia Galanga growing in the East Indies and cultivated in China and Bengal. It is frequently referred to as " Galangal major " to distinguish it from the rhizome of Alpinia officinarum growing in China near Hainan. Galangal occurs in short, branched pieces of a reddish-brown color, with numerous circular scars, and has an aromatic and pungent taste. It contains 0.5 per cent, of a volatile oil, the principal constituent of which is cineol ; a pimgent principle, galangol ; an acrid, pungent resin ; 25 per cent, of starch ; and three crystalline principles. Curcuma or turmeric is the rhizome of Curcuma longa, a reed-like plant which is largely cultivated in India and other tropical countries. In preparing the rhizome for market it is sub- jected to a scalding or parboiling process which agglutinates the starch in the cells. While turmeric is used as a condiment, it is also used on account of its color as an adulterant of mustard, rhubarb, and other articles, but is very easily detected. Several forms of curcuma are found in commerce, as " round curcuma," CLASSIFICATION OF ANGIOSPERMS. 495 consisting of the main rhizome, and " long curcuma," composed of the short branches. They occur in cyhndrical or ovoid pieces, Fig. 273. Zingiber officinale, the rhizome of which constitutes the ginger of the market. Entire plant showing rhizome and roots, a leaf- branch and a flower-branch, as also scars of previous year's growth after decay of leaf- and flower- branches. A, entire flower; B, sec- tion of flower showing beak-like appendage at the apex of the fertile stamen, which encloses the style; C, three- parted labellum or irregular segment of corolla showing 2 tooth - like staminodes (rudiments of stamens) at the base; D, the ovary with lower portion of style and two epigynous, filiform processes which secrete nectar; E, apex of funnel-shaped, fringed stigma. — After Berg and Schmidt. 2 to 5 cm. long, of a yellowish-brown color externally, bright yel- low internally, and aromatic odor and taste. Curcuma contains 496 A TEXT-BOOK OF BOTANY. I per cent, of volatile oil containing phellandrene and turmerol ; 0.3 per cent, of a yellow crystalline principle, curcumin, which is soluble in alcohol, sparingly soluble in water, forms reddish-brown solutions with alkalies and is converted into vanillin with, weak oxidizing agents. It also contains considerable starch and a small quantity of an alkaloid. Other families of the Scitaminese are of great importance on account of the food-products obtained from them, as the Miisa- cece, which contains the group of plants to which the ranaxa (Musa paradisiaca and M. Sapientum) belongs. To the Canna- cecc belong the cultivated Cannas, one of them, Canna edulis, being grown extensively in the West Indies and Australia as a vegetable, and another, Canna coccinea, which grows in the West Indies and South America, furnishing " Tous les mois," the arrow-root starch of the English and French. To the Maranta- cece belongs Maranta arundinacea, which is cultivated in tropical America, and the rhizome of which yields the starch, Maranta ARROWROOT (Fig. 88, B), and is largely used in the preparation of infants' food. IX. ORDER ORCHIDALES OR MICROSPERM^. The most important family of this order is the Orchidace.e or Orchid Family. The orchids are the most highly specialized of the Monocotyledons. They are perennial herbs with diverse habits, many tropical species being epiphytes, and of varying mor- phological structure, which is particularly evident in the zygo- morphic flowers. The perianth consists of 6 segments. The 3 outer correspond to sepals and are similar. Two segments of the inner circle correspond to petals and are alike, while the third, which is known as the lip, is remarkably modified, being usually larger, often spurred, and frequently reversed, being turned for- wards and downwards by the twisting or torsion of the ovary. Only one of the stamens — the anterior of the external whorl — is developed and bears an anther. The other stamens are entirely wanting or present as staminodes (except in Cypripedium and the Apostasieae). The filament is united with the style to form a column, the so-called " stylar v'^lumn," and the anther is thus placed on its apex, and behind the stigma. The 3 carpels form a unilocular ovary with 3 parietal, deeply bifid placentae. TJie fruit CLASSIFICATION OF ANGIOSPERMS. 497 is a pod or capsule, which dehisces mostly by means of 6 valves, and contains numerous minute seeds, which are without endo- sperm, and the embryo of which lacks frequently any trace of external organs. The seed-coat is membranous and loose. Fig. 274. A fruiting plant of Vanilla planifolia, an epiphytic orchid, which is indige-- nous to Mexico and extensively cultivated in tropical countries, especially in Mexico and Java. The photograph is of a plant growing in Dominica, an island of the West Indies, and shows the long, elliptical leaves, also some of the long, slightly curved, slender pods. The latter are not fragrant, but develop their characteristic aroma by a process of slow curing. — Reproduced by permission of The Philadelphia Commercial Museum. Vanilla planifolia, which yields the official vanilla, is a high- olimbing plant with long internodes and distinct nodes from which arise more or less oval or broadly lanceolate, somewhat fleshy leaves and also commonly a single aerial root. The long stem is terminated by a raceme, flowers also arising in the axils of the 32 498 A TEXT-BOOK OF BOTANY. Fig. 275. Moccasin Flower or Pink Lady's Slipper (CyPripedium acaule), one of the commonest and most beautiful of the orchids, found growing in sandy and rocky woods from Newfoundland to North Carolina, and westward from Minnesota to Kentucky. The crimson pink flowers are solitary at the summit of long scapes; the lip is large inflated, slipper-shaped, drooping and with a fissure in front instead of a circular opening as in the other species. — After Troth, leaves for some distance back on the stem. The flowers are yel- lowish-green and the segments of the perianth are similar, and erect or spreading. The lip is united with the column, forming a CLASSIFICATION OF ANGIOSPERMS. 499 Fig, 276. Round-leaved Orchis (Habenaria orbiculata), an interesting orchid found growing in rich deep woods in the north temperate regions of the United States. It has a leafless scape, at the base of which are two orbicular or elliptical leaves spreading flat on the ground. The flowers are in a loose raceme, greenish-white, the lip being oblong linear and about the same length as the spur. — After Troth. A TEXT-BOOK BOTANY. Fig 277. White Fringed Orchis (Habenarta bUphari glottis), an attractive and rather common orchid growing in bogs and peaty lands throughout the eastern and centra! United The stems are from 4 to 6 dm., in length, terminated by many-flowered spike. Ihe white, the lip being copiously fringed and the spur about 2 cm. m length.— After States flowers are Troth. cylindrical body which is strongly concave on one side and spread- ing at the upper portion. The pollinia are granular. Pollination CLASSIFICATION OF ANGIOSPERMS. 501 may be efifected by insects, but is usually brought about by arti- ficial means (hand-pollination). The fruits require several months to become fully grown, and an 'equal period of time is necessary for their maturity, which is indicated by their yellow color. They are then gathered and cured by alternately steaming and drying them, until they acquire the dark brown color and the odor of the commercial article. Vanilla is cultivated in all tropical countries where the temperature does not fall below 18° C, and the humidity is considerable. Usually vanilla culture is combined with that of Cacao. The plants begin to yield fruits the third year and continue bearing for thirty or forty years (Fig. 274). The yellow-flowering Cypripediums of the United States (C. parviflonim and C. parviflorum puhcsccns) yield the cypripedium w^hich was formerly official. The plants are a foot or two high. The leaves are oval or elliptical (in the latter) or elliptical or lanceolate (C parviflorum). In C. pubescens the lip is pale yellow with purple veins, 25 to 50 millimeters long, and possesses a tuft of white, jointed hairs at the throat. In C. parviflorum the lip is smaller and non-hairy. C. acaide is showm in Fig. 275. The root-stocks of a number of Orchids are rich in mucilage and yield the drug salep or a product resembling it. Salep occurs in the form of globular or somewhat flattened, more or less trans- lucent, light yellowish-brown tubers, 2 to 4 cm. long, of a horny texture and a mucilaginous taste. The principal constituent is mucilage, which originates in the cell-contents. It may contain in addition either starch or sugar. While the Orchidaceae, which contains about 6,000 species, ranks second in numbers to the Compositae, there is probably no family which exceeds it in interest. The plants are extensively cultivated, and some of their flowers are the highest priced known in the commercial world. There are few localities in which there are not some orchids to be found, illustrations of several of which are here shown (Figs. 275 to 279). B. CLASS DICOTYLEDONE^. The following are some of the prominent features of the Dicotyledons: (i) The leaves are reticulately (open) veined and usually with an irregular margin, being sometimes deeply lobed ; 50^ A TEXT-BOOK OF BOTANY. Fig. 278. Arelhtisa bulbosa, an Orchid growing in bogs from Newfoundland to South Carolina, and west to Minnesota. It produces a solitary magenta-crimson flower on a long, slender scape, in the sheaths of which a solitary linear leaf arises and protrudes after the flower opens. In the illustration are shown a number of plants, some of which show the small bulbs at the base. — After Troth. (2) the parts of the flower are usually in circles of 2 to 5 each; (3) the stems and roots generally increase in thickness by means of a cambium, and the vascular bundles are open, varying from CLASSIFICATION OF AXGIOSPERMS. 503 Fig, 279. Rattlesnake Plantain, a rather common orchid, variously known as Epi- Pactis, Peramium, or Goodyera pubescens. It is generally found growing in coniferous woods and characterized by Ihe dark-green basal leaves with their prominent nerves and numerous white reticulating veins. The flowers are greenish-white, numerous and crowded on the erect scapes. — After Troth. simple collateral to bi-collateral ; annular rings are formed in the perennial stems; (4) the germinating plant usually has two coty- ledons which are opposite each other. The Dicotyledons are divided into two series or sub-classes, depending upon whether 504 A TEXT-BOOK OF BOTAXY. the parts of the corolla are distinct or are united, namely, the Archichlamydeae and Metachlamydeae. ARCHICHLAMYDE/E OR CHORIPETAL^. The Archichlamydese or Choripetalae comprise those dicoty- ledonous plants in which the petals are separate and distinct from one another or are entirely wanting. I. ORDER PIPERALES. The plants of this order are mostly tropical herbs and shrubs and possess very small flowers which have neither petals nor sepals. The leaves are simple and without stipules, the most important family medicinally, as well as in other ways, being the Piperace.e, to which the following medicinal plants belong. Piper nigrum is a woody climber that has leathery, grayish- green, ovate-elliptical leaves (Figs. 281, 282), with three prominent middle nerves and two side nerves ; the flowers are perfect, sessile and form an elongated fleshy spike ; the fruit is a berry which is yellowish-red when ripe. The unripe fruit constitutes the BLACK PEPPER of commcrcc. White pepper is the ripe berry of Piper nigrum from which the epicarp is removed, while *' long PEPPER " is obtained from Piper longum, an entirely different plant, and consists of the entire spikes with immature fruits. Piper Cubeba is a climbing perennial, with leathery elliptical- ovate or long elliptical leaves ; the flowers are dioecious and arranged in spikes ; the fruit is a berry, the pedicel becoming much elongated after fertilization. The unripe fruit is the part used in medicine and is official as cubeb. Piper angiistifoliiun yields matico, formerly official. The plant is a shrub growing in Central and South America and is characterized by its long, oblong-lanceolate, deeply reticulate, very hairy leaves. The flowers and fruits are very small and arranged in long, slender spikes, which are frequently found in the drug. Alatico contains 2 to 3 per cent, of a volatile oil, containing a stearoptene matico camphor, which appears to be the most im- portant constituent. It also contains an acrid resin, a bitter prin- ciple, and a crystalline principle, artanthic acid. Other related CLASSIFICATION OF ANGIOSPERMS. 505 ''MM^' I^'* r::h^tica or stinging nettle belongs. Of the stinging nettles the following are used in medicine: Urtica dioica of Europe and naturalized in the United States, U. spatidata of Timor, Laportca crenulata of tropical Asia, L. moroidcs of Queensland, and Girardinia palmata of India. In the small nettle {Urtica iirens) of Europe and the United States an alka- loid has been found, and Laportea stimidans has been used as a fish poison. Bochmeria cordata of Brazil is used as a substitute for Arnica. The fibers of a number of the Urticacese have been found useful, of which the following may be mentioned : Urtica cannabina of Asia, U. dioica, U, urcns and Boehmeria nivea of the Sunda Islands and China, the latter of which yields Ramie, The akene of Dcbrcgeasia edulis of Japan and the rhizome of Pouzohia tubcrosa of China and Japan are edible. VII. ORDER PROTEALES. The members of tiiis group are mostly shrubs and found prin- cipally in the Tropics and southern hemisphere, several species being cultivated in greenhouses for the sake of the beautifully colored flowers which are in crowded inflorescences. The order is represented by but a single family, namely, the Proteacese. The leaves are leathery and vary even on the same plant from sim- ple to compound. The glucoside proteacin and a bitter principle are found in Leucadcndron argentcum and L. concinuHui, both 5i8 A TEXT-BOOK OF BOTANY. of Africa. A gum-resin is found in GrevUlea robusta of Aus- tralia, and a tannin in the bark of Lomatia ohliqua of Chile. A golden-yellow coloring principle is obtained from the flowers of Persoonia saccata of Australia. The wood of Protca grandi- Hora of Abyssinia is used in wagon building, and Leucospcnnum conocarpum of Cape Colony yields a valuable red wood and a tan bark. Banskia ccfnula of Australia and the sugar-bush (Protea melli- fera) of Australia and P. speciosa have a sugary cell-sap. The oily seeds of the Chilean hazelnut {Quevina Avellana) are highly prized as food by the inhabitants. The seeds of Brabeium stellati- folium or wild chestnut of Cape Colony are poisonous when fresh, but on roasting they become edible and are used as a substitute for coffee. VIII. ORDER SANTALALES. This order embraces a number of families which are quite distinct in several respects. a. LORANTHACE^ OR MISTLETOE FAMILY.— The plants are half-parasites with well-developed leaves containing chloroplastids. They live on trees by means of haustoria. To this family belongs the American mistletoe {Phoradendron Ha- vescens), parasitic on oaks, elms, the tupelo (Xyssa), red maple and other deciduous trees. The white, globose berries of this plant are quite poisonous, as are also those of the European mistle- toe {Viscum album) and the oak mistletoe of Southern Europe (LorantJius europccus). Viscum album contains a volatile alka- loid, visciNE, a glucoside and a resinous principle. This sub- stance serves to attach the seeds to the barks of trees, where they germinate, and it is used in the manufacture of bird-lime, which owing to its viscid character is used to catch small birds. b. SANTALACE^ OR SANDALWOOD FAMILY.— The plants are chlorophyllous herbs or shrubs which are common in warm countries, and many of which are parasitic on the roots of other plants. A number of them contain volatile oils, as the wood of various species of Santalum. The official oil of sandal is obtained from the scented wood of the white sandalwood {Santalum album), a small tree growing wild and also cultivated in India and the CLASSIFICATION OF ANGIOSPERMS. 519 East Indian Archipelago. The wood from the East Indies is known as Macassar sandalwood and yields 1.6 to 3 per cent, of oil, while the Indian wood yields 3 to 5 per cent. The oil consists of 90 to 98 per cent, of santalol. Fiji oil of santal is obtained from S. Yasi; and Australian oil of santal from Fusanus acmuinatus and F. spicatus. The Chinese oil is obtained from Santalum Freycinctianum and 6'. Preisci. c. FAMILY BALANOPHORACE^.— The plants of this group are indigenous to tropical and sub-tropical regions. They are root-parasites and develop tuberous rhizomes and fleshy shoots which are yellow and without foliage leaves. Balanophora elon- gata of Java grows on the roots of Ficus and other plants, and contains a large quantity of wax and resin. Sarcophyte sanguinea of Cape Colony, which lives on the roots of certain Acacias, con- tains a principle with the odor of scatol. Cynomoriiim coccinctnn, found in the countries bordering the Mediterranean, has a blood- red, astringent sap. The torus of the flower of Langsdorffia liypo- goca of tropical America is edible. The plant is also rich in wax, and in New Granada it is sold under the name of " Siejas " and burnt like a candle. IX. ORDER ARISTOLOCHIALES. This order includes two families which are very different in their general habits, a. The Rafflesiacese are parasitic herbs that are almost devoid of chlorophyll. The reddish vegetative parts penetrate into the tissues of the host, and from these arise almost mushroom-like flowers which in the case of RafHcsia Anwidii of Sumatra are i M. in diameter, being probably the largest flowers known. The plants of this family are rich in astringent substances. b. ARISTOLOCHIACE^ OR BIRTHWORT FAMILY. — The plants are non-parasitic herbs or shrubs, some of which are twining. The leaves are simple and in many of the plants more or less cordate and reniform. The flowers are perfect and the perianth is 3- to 6-lobed. While the flowers of our native species are rather small and insignificant, those of the tropical plants are extremely curious, being generally of some striking color and of various odd forms. Aristolochia reticulata is one of the plants that furnishes the 520 A TEXT-BOOK OF BOTANY. official drug serpentaria (see \'ol. II). From a slender rhizome with numerous hair-like roots arise one or more short, leafy branches which are more or less simple, somewhat hairy, and bear oblong-cordate, prominent-reticulate, hairy leaves (Fig. 287). The flowers are borne on slender, scaly, basal branohes ; the calyx tube is purplish and curved like the letter " s," being enlarged around the ovary and at its throat. The fruit is a capsule containing numerous flat or concave seeds. An allied species, Aristolochia Serpentaria, furnishes the drug Virginia snakeroot. It is a more delicate plant, the leaves being ovate-lanceolate, acuminate ; the flowers are solitary, and in some cases cleistogamous. This species is found growing in the United States, more especially east of the Mississippi, while Aristolochia reticulata is found west of the Mississippi from Arkansas to Texas. The plants of this genus contain volatile oils, and in addition to the two species mentioned 45 other species are used in medicine in various parts of the world. Asarurn canadense (Canada snakeroot or wild ginger) is a plant common in the Northern United States and Canada (Fig. 288). The long and slender rhizomes are used in medicine. They are 5 to 15 cm. long, about 2 mm. thick, more or less bent and curved, purplish-brown externally ; whitish internally ; the bark is thick, wood with about 12 fibrovascular bundles, pith large : the odor is aromatic ; the taste pungent and bitter. The dn g con- tains 2 to 3 per cent, of a volatile oil containing a fragrant body, asarol ; a pungent, fragrant resin ; a yellow coloring principle which is colored dark green with ferric salts ; and starch. The volatile oil obtained from A. curopocum contains a principle (asa- rone) which forms irritating vapors on heating. X. ORDER POLYGONALES. This order is represented by a single family, the Polygonace.e or Buckwheat family. The plants are mostly herbs, but include some twining vines and shrubs. The leaves are simple, mostly entire, and characterized by having a stipulate appendage (ocrea) which sheaths the stem. The flowers are small, perfect, and with a 2- to 6-parted perianth. The fruit is a 3- to 4-angled akene. The embr>'o is either straight or curved, and the endosperm is mealy. CLASSIFICATION OF ANGIOSPERMS. 52 Fig. 287. Southern serpentaria (Aristolochia reticulata) showing the cordate, reticu- lately- veined leaves, and the clusters of irregular flowers on the lower part of the stem •—After Carson. 522 A TEXT-BOOK OF BOTANY. RUeiihi oiUcinale is the source of the " South China " rhubarb from Szechwan, Kanzu, and Shensi. The plant is a perennial herb resembling the garden rhubarb. The rhizome is vertical and gives rise to a leafy branch terminated by the inflorescence, which is a panicle. The leaves are large, with a sub-cylindrical petiole, Fig. 288. Wild Ginger {Asarum canadense). A, showing habit of plant, consisting of underground root-stock, the kidney-shaped leaves on long petioles, and the short peduncled, bell-shaped flower which develops close to the ground; B, longitudinal section of flower, and C, a transverse section of flower. — Bicknell, in Bulletin Torrey Bot. Club, Nov., iSg?. a cordate or orbicular lamina which is either entire or coarsely and irregularly dentate. There are several nearly related species which also yield the drug. Rheum palmatum of Northern China has leaves which are lobed or deeply incised, which character is especially marked in the variety tanguticum. Rheum Rhaponti- cum, which yields English rhubarb, has leaves which are heart- CLASSIFICATION OF ANGIOSPERMS. 523 shaped at the base and with a more or less irrc^rularly undulate margin. All of these species are more or less common in culti- vation in botanical gardens in Europe. Fig. 289. Curled dock {Rumex crispus) showing two of the lower. long-petioled, oblong. lanceolate and wavy-margined leaves, and a flowering branch, the upper leaves of which are narrowly-oblong and short-petioled. Rumex crispus or curled dock is a perennial herb growing in fields and waste places in the United States and parts of Canada. 524 A TEXT-BOOK OF BOTANY/ Fig. 290. I'ield or sheep sorrel (Rumcx AcetoscUa), a common weed containing- a sour juice and growing in open fields; i to 3 dm. high, having narrow-lanceolate or halberd- shaped leaves, and somewhat reddish flowers in a panicled raceme. — After Brown. The leaves are oblong-lanceolate, with an undulate margin and rather long petiole. The flowers have a 6-parted, dark green perianth, and are perfect or polygamo-dioecious. The fruit is a CLASSIFICATION OF ANGIOSPERMS. 525 dark brown, cordate-winged, 3-angled akene. The dried root is somewhat fusiform, reddish-brown, and with a bitter, astringent Fig. 291. Polygonum pennsylvanicum (Fam. Polygonaceac), one of about 30 species of knotweeds, being common in waste places, all herbaceous, and characterized by the leaves having sheathing stipules. Typical of this group is P. pennsylvaniciun, having lanceolate leaves and short, erect terminal spikes with bright rose-colored flowers. — After Brown. taste. It contains chrysophanic acid, tannin, calcium oxalate, and some of the other constituents found in rhubarb (Fig. 2S9). Rumex Acetosclla (field or sheep sorrel) is a slender annual herb with hastate leaves, having flowers in compound racemes. 526 A TEXT-BOOK OF BOTANY. The leaves contain oxalic acid, both free and in combination with calcium and potassium (Fig. 290). Fig, 292. Bnckwheat {Fagopyrum esculentum): A, transverse section of grain showing pericarp (c), endosperm (n) and slender coiled embryo (e) ; B, transverse section of portion of grain showing epicarp (e), fibrous layer (f), pigment layer (p), outer epidermis of spermo- derm (o), aleurone cells (a), endosperm cells containing starch (n); C, surface view of cells of epicarp; D, isolated fibers of pericarp; E. surface view of aleurone cells; F, isolated par- enchyma cells of endosperm filled with starch grains as seen in buckwheat flour; G, appear- ance of starch grains when mounted in oil and viewed with polarized light ;_ H, swollen and altered starch grains which are two to three times the size of the normal grains. Tannin is obtained from a number of the plants belonging to the Polygonaceae, as the root of Rumex hynienosepalus of Texas CLASSIFICATION OF ANGIOSPERMS. 5-7 which is known as Canaigre; the rhizome of Polygonum Bistorta of Europe which yields the drug Bistorta. Polygonuiu cuspidatum of the gardens contains emodin ; poly- gonin, a glucoside yielding emodin ; and probably emodin metiiyl ether. Riimex ccklonianus of South Africa contains emodin, a volatile oil and a resin. The latter consists of emodin monomethyl ether; chrysophanic acid, physosterol (resembling rhamnol), etc. Polygonum Hydropiper and P. aviculare, both common in the United States, are poisonous to sheep. A number of the plants of this family yield food products. Buckwheat is the fruit of Fagopyrum csculentum indigenous to Central Asia and cultivated in many parts of the world ( V\g. 292 ). Some are also cultivated as ornamental plants, as the Prince's feather {Polygonum orientale). XI. ORDER CHENOPODIALES OR CEXTROSPERM.E. This order includes seven families, in all of which the embryo is curved or coiled, and the reserve consists chiefly of perisperm. a. CHENOPODIACE^ OR GOOSEFOOT FA:\IILY.— The plants are annual or perennial herbs with simple leaves and small perfect flowers, the fruit being a utricle. The fruits of a number of the group contain volatile oil, and are used in medi- cine, as the common wormseed (Chenopodium ainbrosioides anthelminticiim), which is found in waste places in the United States. Most of the oil is distilled in Maryland and is known in comrnerce as *' Baltimore oil." Chenopodium mcxicaniim yields saponin. Atriplex hortensis of Tartary yields indigo. The ash of very many species of Atriplex as well as genera of the Chenopodiacese yields soda. The seeds of several species are edible, as of Chenopodium vivid e of Europe and Asia, C. Quinoa of Chile, etc. Seeds of Spinacia tetandra of the Orient are used in bread-making. A number of species are used as garden vegetables, as spinach {Spinacia oleracea) and beet {Beta vulgaris). The SUGAR BEET {Beta vidgaris Rapa), which contains from 4 to 15 per cent, of cane sugar (sucrose), is largely cultivated in Germany, as well as to some extent in the Ignited States, and is an important source of cane sugar. While the juice of the beet 528 A TEXT-BOOK OF BOTANY. contams a larger amount of nitrogenous substances than that of the sugar cane, it is practically free from invert sugar. b. AMARANTACEtE.— The plants are weed-like and much resemble the Chenopodiaceae. They yield anthelmintic principles, edible seeds, and the leaves of a number of species are used as vegetables. The ash yielded by some species contains potash, as Achyranthes aspera and Amaranthus ruber. Some are ornamental plants having a fasciated inflorescence, as the Cock's-comb (Celosia cristata). c. NYCTAGINACE/E OR FOUR-O'CLOCK FAMILY.— The plants are mostly herbs grov^ing in America. The leaves are entire and simple, and the flowers are regular and in terminal or axillary clusters. The perianth consists of a 4- to 5-lobed corolla- like calyx. The most common representative of this family is the Marvel-of-Peru or four-o'clock {Mirabilis Jalapa). While this plant is an annual in the United States, in the Tropics the tuberous root is used as a substitute for jalap, and is sometimes sold for it. The seeds of this plant are edible, as are also the leaves of several species, as of Bai-Jiavia crecta, which are used as green vegetables. Some members of the group, as Bougainvillea spectabilis, are handsome plants with bright rose-colored bracts which envelop the small greenish flowers. d. PHYTOLACCACE^.— The plants of this family are mostly tropical and are represented in this region by only one species, namely, the common poke {Phytolacca decandra), the root and fruit of which are used to some extent in medicine. This is a succulent, branching herb i to 4 M. high, having a large perennial root. The stem is hollow except for the thin, papery partitions. The leaves are simple, ovate-lanceolate, petiolate. The flowers are in racemes and characterized by having ten stamens. The fruit is a dark purple, juicy berry (Fig. 293). The roots of this species as well as others contain powerful drastic principles, as Pirctinia littoralis and Anisonieria drastica of Chile. Phytolacca abyssinica contains saponin, and a red color- ing principle is found in the berries of Phytolacca decandra and Rivinia tinctoria of Venezuela. The leaves of some species of Phytolacca are used as greens. e. AIZOACE^. — This is a group of mostly tropical plants. CLASSIFICATION OF ANGIOSPERMS. 529 Fig. 293. Poke weed {Phytolacca decandra), a common weed growing in low grounds and waste places. The plant is a perennial herb, usually sending up from a large, fleshy root a number of stout stalks, i to 3 M. high; the leaves are ovate-oblong, and opposite which may arise the racemes of whitish flowers. The roots are quite frequently .mistaken for parsnips, and when eaten may cause serious illness. The young shoots and leaves are sometimes gathered in the spring and may be used for a table vegetable. The juice of the berries is said to have been used in Portugal to color Port wine. — After Brown. very many of them having fleshy leaves and adapted to arid re- gions. Many of the plants, particularly those belonging to the genus M esembryantliemum, are much prized on account of their^ 34 530 A TEXT-^BOOK OF BOTANY. beautiful flowers, which expand only in the sunshine. The com- mon ice-plant of the gardens, so called because of the numerous glistening globules of water which cover the leaves, is M. crystal- FlG; 294. Soapwort. Bouncing Bet (SaPonaria officinalis), a perennial herb growing to a height of 3 to 6 dm. and producing opposite, entire leaves, and cymose clusters of rose- colored flowers, commonly double. This plant has been more or less cultivated; it has, however, escaped from the garden, and, in spite of its beauty, has become a troublesome weed in some places. The plant contains saponin and therefore forms a lather with water. It has been used as a detergent. — After Brown. linum. This plant as well as other species of Mesembryanthemum are used in medicine. The ashes yielded by the plants of this family also contain soda. The seeds of some species of Mesem- CLASSIFICATION OF ANGIOSFERiMS. 531 bryanthemum as well as other members of this family are edible, and the leaves of some species are used as vegetables like lettuce. /. PORTULACACE^.— The plants are fleshy or succulent herbs mostly indigenous to America. The two common represen- tatives are the spring beauty (Claytonia virginica), the tubers of which are rich in starch, and purslane (Portulaca olcracea), some- times used as a green vegetable. The seeds of the latter plant as well as of other species of Portulaca are used in medicine. g. CARYOPHYLLACE^.— The plants are annual or peren- nial herbs, often swollen at the nodes, with opposite, entire leaves, and usually perfect regular flowers. The perianth has a distinct corolla of 4 or 5 petals. The fruit is a capsule and the seeds are half anatropous. The plants are most abundant in the northern hemisphere ; and some of them are quite showy, as the carnation (Dianthus caryophyllus) and pinks {Diautlms species) and the cultivated pink or Sweet William {D. barbatiis). A number of the members of this_ group contain saponin, as Bouncing Bet {Saponaria officinalis), which, is naturalized in the United States (Fig. 294), Gypsophila Strut Jiium of Spain and other species of this genus, as well as species of Lychnis and Hcr- niaria. The leaves of Paronychia argcntea are used in Morocco as a substitute for tea. The roots of Sclcranthiis pcrcn- nis of Eastern Europe are inhabited by an insect [Coccus polonica) which is used in the preparation of a red dye. The fleshy stitch-wort (Alsine crassifolia) of Europe and the United States is poisonous to horses. XII. ORDER RANALES. The plants are mostly herbs, but include some shrubs and trees, and comprise eight families of economic importance. a. NYMPH^ACE^ OR WATER LILY FAMILY.— These are aquatic perennial herbs with thick root-stocks and floating, peltate leaves. The flowers are perfect and have large petals. The seeds are enclosed in an aril, and the embryo has rleshy cotyledons. Nuphar luteum of Europe and Middle Asia contains the alka- loid nupharine and tannin, the latter of which splits into ellagic and gallic acids. The yellow pond lily {Xynipha^a adrcna) of the 532 A TEXT-BOOK OF BOTANY United States contains similar principles. The seeds and rhizomes are rich in starch and are used as food, in some cases starch being manufactured from them, as of various species of Nynnphoca, Nelumbo (Lotus) and Victoria, and Envy ale ferox. h. RANUNCULACE^ OR CROWFOOT FAAIILY.— These are annual or perennial herbs with simple or compound leaves, regular or irregular flowers, and fruits which are achenes, follicles, or berries. Fig. 295. Fruiting top of Golden Seal (Hydrastis canadensis), showing the two large palmate leaves, above one of which is a berry-like fruit which is bright red when ripe, Hydrastis canadensis yields the official drug hydrastis. From a short, thick, horizontal rhizome with numerous slender roots rises a short stalk with a few palmately lobed, reniform, petiolate, pubescent leaves. The flowers are small, solitary and greenish- white, and the fruit is a head of crimson berries somewhat resem- bling the raspberry (Fig. 295). Cimicifuga racemosa (black cohosh or black snakeroot) yields the official drug cimicifuga. This is a tall perennial herb with large knotty rhizome, large decompound leaves, and a long raceme of white flowers (Fig. 296). CLASSIFICATION OF ANGIOSPERMS Fig 206 A group of transplanted wild plants with a plant of Cimicifuga racemcsa in the foreground, showing the characteristic, large, decompound leaves and long raceme of flowers. , Aconitum Napellus yields the official drug aconite (Fig. iSO). This is a perennial herbaceous plant indigenous to Europe and extensively cultivated. From a tuberous root arises a simple leafy 534 A TEXT-BOOK OF BOTANY. stem I with palmately lobed or divided leaves, and large, irregular, blue flowers which form a rather loose panicle (Fig. 297). The sepals are 5 in number, the posterior upper one being large and Fig. 297. Acomtum Napellus . A, one of the long-pctiolate. dividrd leaves; B, epi- dermal cells of lower surface; c, an epidermal cell of the upper surface; D, transverse sec- tion through one of the principal veins showing two fibrovascular bundles, and strongly collenchymatic cells beneath the lower epidermis; E, one of the few hair? from the petiole; F, lignified bast fibers surrounding the sieve in the petiole; G,. longitudinal section through fibrovascular bundle showing spiral and reticulate tracheae (t), bast fibers (b) and some of the collenchyma cells (c), those at the left exhibiting longitudinal pores which give a crystal-like effect. helmet-shaped. The petals are 2 to 5 and rather small ; the two posterior or upper ones which are hooded and concealed in the helmet-shaped sepal are nectar-secreting (Fig. 223, E). The fruit is a follicle and contains numerous small seeds. CLASSIFICATION OF ANGIOSPERMS. 535 Fig 298. Wood anemone, wind flower (Anemone quinque folia) . one of the earliest flowering woodland plants. It is a low. slender plant with 3 ^"^°"^^;.^^;;=^fl^;;'",7'"«Vhe involucre, from the junction of which arises a P^duncle.bearmg a sohtary flower The sepals va;y in number as well as in color; there are generally 5. which are usually whtt.sh. or slightly tinged with purple.— After Brown. Delphinium Staphisagria, which yields the official staphisagria or stavesacre, is a handsome, tall, biennial larkspur, with dark green, palmate 5- or 7-lobed leaves and blue or purplish flowers in 536 A TEXT-BOOK OF BOTANY. Fig. 299. Wild Columbine {Aquilegia canadensis) , one of the most interesting plants of the Ranunculaceae. It grows in the crevices of rocks and in open woods, and is a very- striking plant, with its 5 long-spurred, scarlet petals. A number of species of Aquilegia are cultivated, and their flowers show considerable variation in form and color. — After Brown. racemes. The flowers are zygomorphic and somewhat resemble those of Aconite. CLASSIFICATION OF ANGIOSPERMS. 537 Pulsatilla, which was formerly official, is obtained from sev- eral species of Anemone growing in Europe. These are perennial herbs (Fig. 206) with basal leaves which are deeply lol)ed or dissected, those of the stem forming a kind of involucre near the flower. The flowers are rather large and with numerous i)etaloid sepals. The fruit is a densely woolly achene in those species which are used in medicine. The entire plant is used and contains an acrid volatile oil, the principal constituent of which is an anemone camphor (anemonol). The latter is easily decomposed into anemonon, which on fusion becomes exceedingly acrid. Similar principles are found in other species of Anemone as well as in certain species of Ranunculus (buttercup) and Clematis Jltalba of Europe. Very many of the other Ranunculaceae contain active princi- ples. The glucoside helleborein, which resembles digitalin in its medicinal properties, is found in Hellehorus niger, the black HELLEBORE of Europc, and probably in other species of Helleborus, as well as in Actoca spicata, the baneberry of Europe, and Adonis vernalis, the false hellebore of Europe and Asia. c. BERBERIDACE^ OR BARBERRY FAMILY.— The plants of this family are herbs or shrubs with simple or compound leaves, and flowers either single or in racemes (Figs. 134, E: 81, T). The fruit is a berry or capsule. Berheris Aquifolium (trailing mahonia) yields the unofficial drug berberis. It is a low, trailing shrub with 3- to 7-compound, scattered leaves. The leaflets vary from oval to nearly orbicular, are obtuse at the apex, slightly cordate at the base, finely reticulate, and spinose-dentate. The flowers are yellow and in dense ter- minal racemes. The fruit is a blue or purplish berry. Caulophyllum thalictroides or blue cohosh of the Eastern United States is a perennial herb with a thick rhizome and large ternately compound leaves (Fig. 300). The flowers are small and greenish-purple. The fruit is peculiar in that it resembles a berry and consists only of blue, globular, naked seeds, the pericarp being ruptured and falling away soon after fertilization. The rhizome and roots were formerly official. It is a horizontal, much branched rhizome with broad, concave stem-scars, and numerous roots; it is grayish-brown externally, sweetish, slightly bitter and 538 A TEXT-BOOK OF BOTANY. somewhat acrid. The drug contains an acrid, saponin-Uke gluco- side, leontin ; a crystalHne alkaloid, caulophylline ; two resins ; and starch. For analysis of the seeds see Chem. A^ezvs, 1908, p. 180. Podophyllum peltatmn or May apple is the source of the official podophyllum. This is an early, herbaceous, low, perennial plant forming large patches by reason of its long dichotomously branch- ^^^^r '^>^ ^;^-V ^ ^ ^- fc^B^^By^^ *"' i^BHII^^^^^^^^ Fig. 300. A group of transplanted plants, showing in the upper portion a fruiting plant of blue cohosh {CaidophylUim thalictroides). ing rhizome (Fig. 182). It forms two kinds of branches, one bearing a single, peltate, 5- to 7-lobed leaf ; and another bearing in the axil of two similar leaves a white flower which gives rise to a large, yellowish, ovoid berry which is edible. d. MENISPERMACE^ OR MOONSEED FAMILY.— The plants are climbing or twining, herbaceous or woody vines with simple, entire or lobed leaves and small, greenish-white dice- . CLASSIFICATION OF AXGIOSPERMS. 539 cious flowers. The fruit is a drupe and contains a characteristic crescent-shaped seed. Menispermum canadcnse or Canada moonseed yiehls tlie druj^ menispermum which was formerly official. It grows in tlie Xorth- ern United States and Canada and is a high-chmbing vine with broadly ovate, cordate and 3- to 7-lobed leaves (Fig. 180). The flowers are in panicles giving rise to a characteristic cluster of bluish-black berries. The rhizome occurs in pieces which are 5 to 7 dm. long and 2 to 5 mm. in diameter ; externally it is longitudinally wrinkled, of a yellowish-brown color and somewhat resembles Sarsaparilla. In transverse section, however, it is very distinct (Fig. 194). The drug has a bitter taste and contains a bitter alkaloid menispine, berberine and starch. In addition it contains the alkaloid oxyacan- thine which is also found in Bcrbcns vulgaris of Europe and the West Indies. Jateorhiza palmata yields the official drug calumba ( columbo). The plant is a herbaceous climber somewhat resembling Meni- spermum, the leaves being more decidedly lobed. The flowers form long racemes. Chondrodendron tofucntosuin, the source of the unofficial drug pareira, is a high woody twiner. The leaves are large, petiolate, broadly ovate or rounded, slightly cordate, and densely tomentose on the lower surface. Anarnirta paiiiculata is a woody climber of the East Indies. The fruits, known as fishberries or Cocculus, are used as a fish poison by the natives and contain the neutral i^rinciple picrotoxin. A'ery many other plants of the Alenispermaccce contain power- ful toxic principles and are used as fish poisons and as antidotes to snake poison. Several species of Abuta are used in the prepara- tion of curare poison. e. MAGNOLIACE^ OR MAGNOLIA FAMILY.— The plants are mostly trees or shrubs and are represented in the L^nited States by the magnolias and tulip tree {Liriodcndron Tulipifera). The latter is a magnificent tree with characteristic leaves (Fig. 204) and large, fragrant, orange-colored, tulip-like flowers. The plants of this family contain a variety of constituents. 540 A TEXT-BOOK OF BOTANY. Ethereal oils containing anethol and resembling those of anise are found in the fruit of Illicium anisattim (/. verum) or star ANISE, a small evergreen tree growing in the mountains of South- ern China. A volatile oil with a disagreeable odor is found in a closely related species /. religiosmn (Shikimi) of Japan. The fruit of the latter plant is known as Japanese star anise and contains in addition a poisonous neutral principle. The fruits of both star anise (Illicium ) and the Japanese star anise are made up of 6 to 8' radially arranged follicles, which are dark brown, dehis- cent on the upper (ventral) surface and each contains a single, brown, shiny seed. Star anise has an odor and taste resembling anise. Japanese star anis'e has a bitter taste and in addition is brownish-black, very woody and strongly beaked. Volatile oils are also found in the flowers of the various species of Magnolia and in MicJielia Champaca found in the Malay Archi- pelago and cultivated in India and Brazil, and in M. nilagirica of India, the latter being used in perfumery. Winter's bark is derived from Dr'unys IVintcri, a shrub of South America. It occurs in quills wliich are from 5 to 10 mm. thick ; externally it is grayish-brown and covered with numerous lichens ; the fracture is short, the broken surface being marked by stone cells and resin canals ; the odor is fragrant ; taste aro- matic, pungent and bitter. The drug contains a volatile oil which consists essentially of a hydrocarbon known as winterin ; it also contains a resin. A crystalline principle magnolin, a glucoside and a volatile oil are found in Magnolia macro phylla (or cucumber-tree of the Southern States) and il/. tripetala or umbrella tree growing southward from Pennsylvania. A bitter principle liriodendrin, a volatile oil, an alkaloid, and a glucoside are found in the tulip poplar or tulip tree. The bitter and aromatic bark of Michclia )nontana of Java is used like cascarilla ( Euphorbiaceae). A bitter resin is found in the fruit of Talauuia Plmuicri or the Antilles. A glucoside which dissolves the blood corpuscles is found in Talau))ia macrocarpa of Mexico. A red coloring principle soluble in water occurs in the leaves of Michelia Tsiampaca of Java. The fruits of Schizandra propinqua of Nepal and Kadsiira Rox- CLASSIFICATION OF ANGIOSPERMS. 541 burghiana of Japan contain considerable mucilage and are edible. The latter plant is also used as a hair-restorer. l'>om the ash of Schisandra chincnsis of China and Japan sodium chloride is obtained. The flowers of Magnolia Juglans are used to flavor tea and tlie Fig, 301. North American papaw (Asimina triloba): A, branch showing lateral nodding flower and the large, pinnately-veined, entire leaves; B, section of the oblong, 3-seeded berry; C, D, seeds, the one in longitudinal section. — After Baillon. leaves of Talauma ovata are used as a substitute for tea in Brazil. /. ANONACE^ OR CUSTARD-APPLE FAMILY.— These are shrubs or small trees chiefly inhabiting warm-temperate and tropical regions. They yield very many economic products. The fruit of Xylopia brasilensis is used as a substitute for cubeb. Some yield fruits having an aroma similar to that of nutmeg, as 542 A TEXT-BOOK OF BOTANY. Monocarpia Blancoi of Africa and Jamaica. The flowers of Cananga odorata of tropical countries are used in the preparation of a pomade from which the perfume Ylang-ylang is made. Ethereal oils are also found in other species, as Unona ligularis of Ambyona, the seeds of which are used in perfumery. The bark of Popowia pisocarpa of Java contains an alkaloid. Fig. 302. Nutmeg trees growing in Singapore. The trees are handsome, evergreen shrubs, extensively cultivated in the East Indies, and to some extent in tropical America. — • Reproduced by permission of The Philadelphia Commercial Museum. The seeds of Xylopia salicifolia of Trinidad and X. muricata of Jamaica are very bitter, as are also the wood and bark of X. glabra of the West Indies. The seeds of Asimina triloba, the North American papaw (Fig. 301), contains an emetic principle. This plant should not be confounded with Carica Papaya (Caricaceae) which contains the ferment papain. Many of the Anonaceae yield large succulent fruits, some of which are edible, as the sugar apple obtained from Anona sqiia- CLASSIFICATION OF ANGIOSPERMS. 543 mosa and custard apple from A. reticulata both abundant in the Tropics. The fruit of A. muricata sometimes weighs as much as two kilograms. g. MYRISTICACE^ OR NUTMEG FAMILY.— This family is represented by the single genus Myristica. Nutmeg Fig. 303. Young plant of Cinnamomum zeylanicum grown from cutting. (Fig. 302) and mace are obtained from Myristica fragrans, an evergreen tree with ovate, petiolate, coriaceous, entire and pinnately-veined leaves. The flowers are small, yellow and dicE- cious. The fruit is a berry having somewhat the shape and size of the green fruit of black walnut. It has a line of dehiscence, and when ripe is yellow. The arillode of the seed constitutes mace, 544 A TEXT-BOOK OF BOTANY. while the kernel is the nutmeg, the pericarp of the fruit and coat of the seed being rejected. h. LAURACE^ OR LAUREL FAMILY.~The members of this family are chiefly shrubs and trees which are distributed mostly in the Tropics, although a few are found in the temperate zones (Fig. 280, F). Sassafras officinale. — This is a tree common in the eastern and central portion of the United States and is characterized by its rough bark and its i- to 3-lobed leaves, from whence it received its former name Sassafras variifoliiim (Fig. 203). The flowers are yellow, dioecious and appear in the spring before the leaves. The fruit is an oblong, blue drupe. Cinnamomum zeylanicum, which is the source of the Ceylon cinnamon (Fig. 304), is a small, handsome, evergreen tree with opposite, coriaceous, broadly lanceolate, 3- to 5-nerved leaves (Fig. 303). The flowers are yellowish-white, hermaphrodite, or both pistillate and staminate. The fruit is a black, ovoid berry. The oil of Ceylon cinnamon from the bark and branches is charac- terized by its content of cinnamic aldehyde ; from the leaves by eugenol ; and from the root bark by camphor. C. Cassia which yields Cassia cinnamon is a tree growing in China, Sumatra, and cultivated in Java. It has long, oblong-lanceolate leaves which are pubescent on the lower surface. Cassia cinnamon (bark) is also obtained from Cassia Burmanni. Saigon cinnamon (see Vol. II) is derived apparently from wild trees growing in the mountainous regions of Anam, the botanical origin of which has not been determined. The volatile oils of the members of the Lauraceae vary con- siderably in composition. In addition to the oils of Sassafras and Cinnamon the following may be mentioned : A cinneol- containing oil is found in Cinnamomum Oliveri of Australia, Umbelhdaria californica of Western North America and Laurus nobilis the noble laurel of the Mediterranean and Mexico. A bor- NEOL-containing oil is obtained from the root of Dicypellium caryophyllatum of Guiana, the wood of which is known in Cayenne as rose-wood. An oil containing a notable amount of METHYL SALICYLATE IS obtained from the spice-bush {Lindera Benzoin) of the United States. CLASSIFICATION OF ANGIOSPERMS. 545 \WS ^^MuLwffr^BMLujJi^ mM'^m^ P#Mitm ^^^•:^^>r-'^"S- k^0^^^ s^^w-^^^ ^fp"^^' 8v-j^.<^--{3 iss 1^.-.^'=1^ Fig. 304, Cutting cinnamon in Ceylon. Cinnamomum zeylanicum is a native of the forests of Ceylon and is extensively cultivated, not only on the western coast of that island but in other countries of tropical Asia. The manner of cultivation is such that a number of stems are a:llowed to grow from a single root. When of sufficient height these are cut down and the smaller branches removed, as shown in the illustration. The bark is then separated from the thicker portion of the stems, gathered into bundles and placed under mats until a slight fermentation takes place. After the corky layer is removed the product is ready for the market. — Reproduced by permission of The Philadelphia Commercial Museum. Cinnamoinum Camphora, or the camphor tree, is indigenous to China, Japan and Formosa, and is now cuhivated in many warm 35 546 A TEXT-BOOK OF BOTANY. countries as a shade and ornamental tree, growing very well in Southern California and the Southeastern States. All parts of the tree contain a volatile oil which on oxidation yields camphor, which latter is obtained on distillation and sublimation. Camphor of poor quality is obtained from C. Parthenoxylon of Burmah, Malaya and China, and C. glanduliferum of the Himalayas. Cam- phor is also a constituent of other ethereal oils of this same family, as the Massoy bark oil obtained from the root bark of C. zcylanicum and C. Burmanni of Java. A EUGEXOL-containing volatile oil is obtained from Ravensara aromatica of Madagascar, and MacJiilus Thunbergii of Japan. Eugenol is also found in oil of laurel leaves (L. nobilis), Massoy bark oil, the oil of the leaves of Ceylon cinnamon, and the oils obtained from Cinnainojiiimi Cidilazvan of the Malay Peninsula and China, and C. IVightii of East India, and possibly is also found in Dicypellhim caryophyllatum. The wood and the bark of Nectandra or Beeberu (Nectandra Rodioci) of Guiana and Brazil contain several alkaloids, one of which is known as beeberine and is supposed to be identical with the alkaloids in Biixiis sciuperz'irens (Fam. Buxacese) ; pelosine found in Pareira ; and paricine found in the bark of the cultivated cinchonas of Java. Coto bark, which is used in medicine, is obtained from an unknown tree in Northern Bolivia belonging to this family. The bark contains a volatile oil having a pungent taste, and a volatile alkaloid. Fatty oils are obtained from Ravensara aromatica of Mada- gascar, Litsea glaiica of Japan and other species of Litsea found growing in Cochin China and India. A red sap with a very fetid odor is obtained from Ocotea fartens of tropical and sub-tropical America, and the stink-wood of South Africa (0. bidlata). XIII. ORDER RHCEADALES OR PAPAVERALES. These are mostly herbaceous, seldom woody, plants. The flowers are perfect and the fruit capsular. This order includes two families of importance medicinally. a. PAPAVERACE^ OR POPPY FAMILY.— These are herbs with a milky or colored latex. Papaver souiniferum or opium poppy is an annual herb i to 2 CLASSIFICATION OF AXGIOSPERMS. 547 M. high. The stem is sparingly branched, witli alternate, deeply lobed, pubescent, clasping (by a cordate base), dull green leaves (Fig. 305, A). The flowers in the variety album, from which opium is obtained, are white or silver-gray, and in many cultivated varieties are large and extremely showy. The two sepals drop away with the expansion of the corolla ; the ovary is smooth, more or less globular and subtends the radiate stigma; the fruit is a Fig. 305. A, Opium poppy (Papaver somniferum); B, California poppy (Eschs'-hoit- zia calif ornica) showing flower (a), and capsules (b, c), one of which (c) is dehiscent. — After Schimper. capsule (Fig. 2t^^), dehiscing by means of terminal pores, and contains a large number of extremely small white seeds, known as MAW-SEED, and which yield a fixed oil known as poppy-oil. The latex of this plant (Figs. 306, 307) yields opium. Other allied members of the Papaveraceie possess narcotic properties, but the alkaloid morphine has not been isolated from any of them, as the California poppy {Eschscholtzia calif oniica) (Fig. 305, B) ; the Mexican poppy {Argcuwuc uicxicana') ; //y- pecoum procumhens, and Fumaria plicata, both of Southern 548 A TEXT-BOOK OF BOTANY, Europe. These latter plants probably contain also the alkaloid protopine which is apparently identical with fumarine. Sanguinaria canadensis or bloodroot, the rhizome of which is official. The plant is a small, herbaceous, perennial herb with a red latex. The rhizome is horizontal, short and thick, and gives rise to a single, petiolate, palmately 5- to 9-lobed leaf and a single white flower with a long peduncle (Fig. 308). The capsule is Fig. 306. Poppy fields in the meadows 8 miles northwest of Ping-li, Shensi, China, showing the plants with large terminal flowers. — Reproduced by permission of The Phila- delphia Commercial Museum. oblong, 2-valved, and contains a number of smooth but crested seeds. Chelidonium ma jus (celandine) is the source of the herb CHELiDONiUM which was formerly official. The plant is a delicate branching herb about 0.5 M. high ; with alternate, deeply pinnati- fid leaves ; yellow flowers ; slender elongated capsule resembling that of the mustards, and a yellow latex in every part. Celandine is indigenous to Europe and Asia and is common in waste places in the United States. The drug contains the following alkaloids : CLASSIFICATION OF ANGIOSPERMS. 549 Fig. 307, Poppy fields in Afionkarohissar, Turkish Empire. The capsules are ready to be incised allowing the milky juice to exude, which is then collected and constitutes the opium of commerce. — Reproduced by permission of The Philadelphia Commercial Museum. 550 A TEXT-BOOK OF BOTANY. Chelidonine (identical with stylophorine), chelerythrine (which is fluorescent), and protopine (found also in opium and sangui- naria). It also contains a bitter neutral principle chelidoxanthin and several organic acids (Fig. 309). To this family belong a number of other plants which contain principles similar to or identical with those found in Sanguinaria and Chelidonium, and of these the following are common in the ■ BH |9n Hi HH^H ^^ Fig. 308. A group of transplanted bloodroot plants (Sanguinaria canadensis) show- ing i-fiowered scapes, and the palmately veined and lobed leaves. United States: Yellow or celandine poppy {Stylo phorum diphyl- luiii) and the Dutchman's breeches {Bicucitlla Cucullaria ) . The alkaloid rRoxopiNE (fumarine) is found in the following plants of this family: Sanguinaria canadensis; Chelidonium majus; Styloplwruni diphyllum ; Eschscholtzia calif ornica; Glau- cium cornicidatum of Middle Europe; Bicuculla Cucullaria; Ad- luniia fungosa, the climbing fumitory of the United States and Canada ; Fumar-ia ofRcinalis, the fumitory of Europe, which is naturalized in the United States and Canada ; Bocconia cordata of China and Japan, and B. frutescens of the West Indies, Mexico CLASSIFICATION OF ANGIOSPERMS. 551 and Paraguay; Diccntra pusilla of Japan and several species of corydalis. The tubers of squirrel com or corydalis (Bicuculla canadensis) contain the alkaloidal corydaline. Fig. 309. Celandine {Chelidonium majus), a biennial herb, with pinnately divided leaves, and terminal clusters of small, yellow flowers. The plant has an orange-colored latex. — After Brown. b. CRUCIFER.E OR MUSTARD FAMILY.— These are herbaceous plants with characteristic flowers and fruits. The flowers have four deciduous sepals, four petals which are more or less spreading and clawed at the base, and six stamens which are tetradynamous (Fig. 280, B). The fruit is a 2-celled silique or 552 A TEXT-BOOK OF BOTANY. Fig. 310. Fruiting specimens of the two mustards, the one on the left White Mustard {Brassica alba), and the one an. the right Black Mustard {Brassica nigra). — After Newcomb, CLASSIFICATION OF ANGIOSPERMS. 553 silicle, which varies in shape in the different genera (Fig. 310). Brassica alba (white mustard). — The plant is a slender, branching, more or less hispid (bristly hairy) annual or biennial herb usually less than 0.5 M. high, with deeply pinnatilid lower leaves and lanceolate, dentate upper leaves. The flowers are yellow, and the silique is densely hispid, constricted between the seeds and terminated by a long, flat, sword-likc beak (Fig. 310). The seeds are official as white mustard (Siiiapis alba ) but are known in commerce as yellow mustard. Brassica nigra or black mustard, the seeds of which constitute the official black mustard {Sinapis nigra), is a larger, more branch- ing plant than Brassica alba, being from i to 3 M. high. The silique is erect, more cylindrical and with a slender, filiform beak (Fig. 310). Glucosides similar to those which occur in Brassica alba and Brassica nigra are also found in other species of Brassica, as well as in the following related plants, but the oils produced are not identical; Horseradish (Roripa Armoracia) , the oil being similar to volatile oil of mustard; water cress {R. Nasturtium) ; garden radish (Raphanus sativus) ; Sisymbrium Alliaria of Eu- rope, and the hedge mustard (5'. o^cma/r) naturalized in the United States; turnip {Brassica Rapa) of Europe; field penny-cress {Thlaspi arvense) of Asia and. found in waste places in the Eastern and Middle United States ; the narrow leaved pepper- grass (Lepidium ruderale) naturalized from Europe ; scurvy-grass (Cochlearia officinalis) of Northern and Middle Europe, the herb of which, known as Herba cochlearia, is used in medicine : "honesty" (Lunaria annua) common in cultivation on account of the ornamental use of the dry pods; Parrya macrocarpa of Southern Europe; treacle mustard {Erysimum chciranthoidcs) of Northern Europe and the United States, and garlic mustard {E. Alliaria). The seeds of most of the Cruciferae are also rich in fixed oils, and the commercial oils are obtained from the following species : Wild mustard or charlock {Brassica arvensis) naturalized in the United States from Europe ; Hesperis trisfis of Southern Europe ; cabbage {Brassica olcracea). An indigo- forming glucoside is found in Isatis tinctoria.oi Europe and /. indigotica of China; 554 A TEXT-BOOK OF BOTANY. Neslia paniculata of Europe and the Orient ; and Lepidium ozvai- hiense of the Hawaiian Islands. Shepherd's purse {Capsella Bursa-pastoris) contains an alkaloid (bursine) and tannin. The leaves and roots of many of the Cruciferse are used as garden vegetables, and some are cultivated as ornamental plants. The seeds of Limaria biennis (or "honesty") contain an orange-red crystalline alkaloid, or possibly a mixture of alkaloids. c. There are several other' families of the Rhoeadales which yield economic products. The Resedace.Ti include the migno- nette {Reseda odorata), the flowers of which yield a fragrant vola- tile oil ; and R. Luteola of Europe, which contains a yellow coloring principle and also an anthelmintic principle. The Moringace.e comprise a single genus, Moringa. The root of M. oleifera of tropical and sub-tropical countries contains a volatile oil resem- bling the volatile oil of mustard, and the stem yields an astringent gum resembling that of Bomhax inalabaricum (Bombaceae). XIV. ORDER SARRACEXIALES. This order Includes several families which are of special inter- est because of the fact that the leaves are of peculiar construction and adapted to the catching and digestion of insects (Fig. 208). Probably all of the plants of this order produce proteolytic ferments resembling those in the pine-apple and are capable of acting upon and digesting animal substance. Some writers have supposed that the properties of these plants might be due to bac- teria present in the liquid contained in the pitchers of the leaves, but there seems to be no question that a distinct enzyme resem- bling trypsin is formed in those plants which have been studied. (a) The genus Sarracenia of the family Sarraceniace.e or pitcher-plant family, is represented in the United States by a number of species. The rhizome of Sarracenia purpurea (Fig. 311) contains several alkaloids, one of which, sarracenine, seems to have some resemblance to veratrine. (&) The Droserace^ or sundew family includes the Droseras or sundew plants and Diona^a muscipula, the Venus's flytrap of North Carolina (Fig. 209). A number of species of Drosera contain a red coloring principle similar to that isolated from the rhizomes of D. Whittakerii of Australia and is a derivative of methylnaphthoquinone. Citric CLASSIFICATION OF ANGIOSPERxMS. 555 Fig. 311. Pitcher Plant {Sarracenia purpurea). The plant grows in peat boRS. and the pitcher-shaped leaves are usually half filled with water and serve as a trap for insects, which are finally digested and furnish the plant with nitrogenous food. The flowers arc single on a naked scape and of a deep purple color, the petals being arched over the style. Many species of Sarracenia are prized by horticulturists because of their odd trumpet- shaped leaves. — After Troth. acid has been found in D. longifolia, a sundew common in the United States as well as in Europe and Asia, (r) The family Nepenthace^ contains the single genus Nepenthes, seveial spe- 556 A TEXT-BOOK OF BOTANY. cies of which are extensively cultivated in greenhouses. The leaves and roots of A^. Boschiana of Borneo contain an astringent principle. XV. ORDER ROSALES. The plants range from herbs to shrubs and trees and have complete flowers which are mostly perigynous. The carpels are solitary, or several either distinct or united. a. PODOSTEMACE^ OR RIVER-WEED FAMILY.— The plants are aquatic and more or less alga-like, and are repre- sented in the United States by the river-weed (Podostenwn Cerato- phyllum), which is a densely tufted plant found in running water attached to stones. The ash of these plants contains a consider- able amount of sodium chloride, the ash of Moiirera Weddelliana of Brazil containing 50 per cent, of salt and being used as a source of table salt. b. CRASSULACE^ OR ORPINE FAMILY.— The plants are chiefly succulent herbs and represented by such plants as houseleek {Sempervivum tectormn), which is cultivated largely as an ornamental plant, and the common sedums, of which there are numerous species in temperate regions. The common mossy stonecrop or wall-pepper (Scdum acre) naturalized in the North- ern United States contains a ferment capable of dissolving the membrane formed in diphtheria and croup ; Sempervivum hahami- feriun of the Canary Islands contains a substance resembling the I'iscine found in certain Loranthacese. Ditch or Virginia stonecrop {Penthonim sedoides) contains tannin. c. SAXIFRAGACE^ OR SAXIFRAGE FAMILY.— The plants are mostly found in temperate regions and among the im- portant members are mitrewort (Mitella), false mitrewort (Tia- rella eordifolia), alum root (Heuchera americana), golden saxi- frage (ChrysGspIenium) , gras-s of Parnassus (Parnassia), mock orange (PJiiladelphiis eoronarius) and the wild hydrangea (Hy- drangea arborescens). The plants are rich in tannin, as the alum root of Eastern and Central North America, which contains 10 to 20 per cent, of xannin. A glucoside hydrangin, a volatile oil, and possibly also a saponin are found, in " seven barks " or wild hydrangea (H. CLASSIFICATION OF ANGIOSPERMS. o:)/ Fig, 312. Early Saxifrage (Saxifraga virginiensis), a perennial herb with a whorl of root leaves from which arise the flower scapes bearing open and loosely panicled cymes. It grows in the clefts of rocks, and the name is derived from the Latin, meaning to break a rock. No doubt because of its habit, medicinal virtues were earlier ascribed to it, and it was used to cure stone in the bladder. — After Troth. arbor escens) \ a glucoside is also found in the root of garden hydrangea {H. paniculata grandiftora) . In this family are also included the gooseberries (Fig. 245) 558 A TEXT-BOOK OF BOTANY. and currants. The cultivated currants are varieties of Ribes rubrum: the cultivated gooseberries are varieties of R. Uva- crispa. Both of these plants are natives of Europe and Asia and have escaped from cultivation in the United States and Canada. The fruits contain fruit-acids and fruit-sugars and are used in a variety of ways. The fetid currant (Ribes prosfratmu) has a very fetid odor and it is said that the flowers of the buffalo currant (Ribes aiirenm) contain hydrocyanic acid. e. HAMAMELIDACE^ OR WITCHHAZEL FAMILY.— The plants are shrubs or trees and are most abundant in sub- tropical countries. Hamamelis virginiana, or witchhazel, the leaves and bark of which are used in medicine, is a shrub which is especially characterized by its asymmetric, undulate leaves and by its produc- ing flowers in the autumn when the leaves are falling and the mature, but not ripe, capsules of the preceding year are still present (Fig. 313). The forked branches of the witchhazel, as also the twigs of the peach and other plants, are used in various parts of the United States for detecting the presence of underground water. These are operated somewhat as follows : The branched arms are held by the operator in a horizontal position and as the operator surveys the field, it is supposed the main stem will dip in the direction indicating either underground water, petroleum, etc. It is the honest belief of the operators that the working of the rod is influenced by agencies — usually regarded as electrical currents following underground springs of water — that are entirely inde- pendent of their own bodies, and many uneducated people have implicit faith in their ability to locate underground waters in this way. Hov/ever, it is held by scientists that the operation of the divining rod is generally due to the unconscious movements of the body or muscles of the hand. Liqiiidambar Styraciflua or sweet gum-tree of the Atlantic coast of the United States and Mexico, is a tall tree with charac- teristic cork-wings on the branches ; 3- to 7-lobed, petiolate, finely serrate leaves ; monoecious flowers, and a spiny, globular, capsular fruit. The tree yields a balsam allied to the official styrax CLASSIFICATION OF ANGIOSPERMS 559 (storax), which is obtained from a very similar tree (L. orient alis) . f. PLATANACE^ OR PLANE TREE FAMILY.— This Fig. 313. Branch of Witchhazel (Hamamelis virgitiiana) showinR alternate, short- petiolate and pinnate-reticulately veined leaves, having a broadly oval ir ol>ovate out- line, round, acute, or slightly acuminate apex; slightly cordate, inequilateral base; and undulate or sinuous margin. /amily consists of but one genus, Platanus, of whicli there are 7 species. It includes the sycamore or buttonwoud {Platanus occidentalis) , one of our largest trees, easily recognized by its 56o A TEXT-BOOK OF BOTANY, mottled exfoliating bark. The leaves are palmately lobed and within the base of the petioles are formed the winter buds. The flowers are staminate and pistillate heads, borne on separate ped- uncles. The fruits are spherical heads about 2 cm. in diameter, composed of ilumerous achenes, and persist on the trees throughout the winter. The wood is not only used for building purposes, but also for butchers' blocks. Fig. 314. Cross-pollination through the agency of a bee, in flower of quince {Cy- ionta vulgaris). A, flowering branch; B, flower showing bee extracting nectar, and masses of pollen adhering to its legs, some of which will fall upon the stigmas of other flowers wtien it visits them; C, ripe inferior fleshy fruit (pome) of quince. — After Dodel-Port. /. ROSACE.E OR ROSE FAMILY.— The plants are herbs, shrubs or trees usually with alternate, stipulate, simple or com- pound leaves, and regular perfect flowers with or without petals, and numerous stamens (Fig. 280, D). The fruit is a pome (Fig. 314), drupe (Fig. 315), follicle or achene (Fig. 236). Prunus serotina or wild black cherry is a tree varying from 10 to 30 M. in height, with a more or less smooth bark marked by prominent transverse lenticels, and showing a tendency to peel ofif in semicircular pieces, which gives the older bark, which is more or less black, a roughened appearance. The leaves and inner CLASSIFICATION OF ANGIOSPERMS. 561 bark have an agreeable aromatic odor; the leaves are oval- or oblong-lanceolate, acute or acuminate, and serrate, the tceih being Fig. 315. Fruiting branch of \\ild black cherry {Prunus 5<-n'/iMa). glandular; the flowers are white and in racemes; tlie fruit is a dark purple or blackish, globular drupe (Fig. .^5). Tlie nearly related species wild cherry or choke cherry ( Pruuns virijimana) 36 562 A TEXT-BOOK OF BOTANY. is a shrub or small tree with broadly oval, acuminate leaves, red or nearly black drupes, and flowers and fruits several weeks earlier than P. serotina. Priinus Amygdalus is a small tree resembling somewhat the peach tree. The leaves are lanceolate, serrate ; the flowers are rose-colored, and the fruit is a. dehiscent drupe in which the leathery sarcocarp separates from the. endocarp, which latter, with the seed which it encloses, constitutes the edible almond of the market. The kernels of someof the seeds are quite bitter (bitter almonds), and some are bland and free from bitterness. By a process of selection plants yieldi'ngthe latter are now extensively cultivated in sub-tropical and warm-temperate regions, and yield the sweet or Jordan almond of the market. In Turkestan some of the almonds have a smooth endocarp. A glucosidal substance having the properties of amygdalin is found in the buds, leaves, bark and seeds, more especially the latter, of some members of the following genera: Prunus, Sorbus (mountain ash), Cotoneaster, Amelanchier, and Eriobotyra {E. japonica or Japanese medlar). Prunus domestica yields the French plum or prune of com- merce. The leaves are ovate or ovate-lanceolate, dentate, and pubescent on the lower surface. The flowers are greenish-white, with a hairy peduncle. The fruit is a drupe, with a black or bluish-black epicarp, a brownish sarcocarp, and a hard, oval, smooth and flattened endocarp. The endocarps of the members ot tne genus Prunus vary greatly. The endocarp in the apricot (P. Anneniaca) is quite smooth, as is also that of the cherry (P. Cerasiis) ; in the peach {Prunus Per- sica) it is reticulate. The bark of Pyrus Toringo yields a yellow coloring principle known in Japan as " dzaini." It also contains a white, crystalline glucoside (toringin), and pyrus-quercitrin, the latter forming yellow needles and on hydrolysis yields quercetin and rhamnose. The bark is also used to adulterate licorice, gentian and other drugs in the powdered form. The apple (Pyrus Malus) , the pear (Pyrus cornmums) , and the quince (Cydonia vulgaris) are inferior fruits known as pomes, the fleshy part developing from the torus and persistent calyx, the core being composed of the united carpels. The edible fruits CLASSIFICATION OF ANGIOSPERMS. 563 of the Rosacese contain a number of i-rlit-acids, sucli as malic, citric, tartaric, and fruit-sugars, as dextrose and le\ ulosc. The acids vary from 0.20 per cent, in pears to 1.50 per cent, in plums ; and the sugars from 4.48 per cent, in peaches to 8.26 per cent, in pears. The carbohydrates mannit and sorbil arc fouiul in the fruit of Prunus Laurocerasus of Europe. \\\ the unripe fruits there is more or less tannin and also a principle known as pixtosk. This latter during the ripening of the fruit is converted into PECTIN, a viscid principle which is further changed into pectic and pectosic acids, the solutions of which gelatinize on cooling, so that these fruits are adapted to jelly making ( see pp. 243, 255 ). Ruhus nigrobaccus, or high bush-blackberry, is a branching shrub I to 2 M. high with reddish, prickly, erect or recurved stems. The leaves are 3- to 5-foliate, the leaflets being ovate, coarsely and unequally serrate, and midrib and petiolules with stout, re- curved prickles. The flowers are white, in terminal racemes and with hairy and prickly stalks. The fruit is broarlly ovoid and consists of an aggregate of drupelets which ripen in August and September. Riibus villosus Ait. {Ruhus canadensis L.) or low-l)lackbcrr\' (Northern dewberry) is a trailing, shrubby, prickly plant the leaves of which are 3- to 7-foliate, the leaflets being oval or ovate- lanceolate, serrate and nearly smooth. The flowers are in racemes and the fruit resembles that of R. nigrobaccus, but is smaller. Ruhus cuncifolius or sand-blackl)erry of the b^astern and Southern States is a small shrub less than 1 M. high, much branched, and with straight or recurved, stout })rickles. The leaflets are ovate or cuneate, and densely pubescent, as are also the young shoots. The inflorescence consists of two to Ave flowers, the petals of which are white or pinkish. The fruit is oblong, more or less cylindrical, and sometimes 20 mm. long. Ruhus Idocus or the cultivated European red-rasj)bcrry is a shrub with a glaucous, bristly stem and with 3- to /-foliate leaves. The flowers are white and the red fruit consists of a caj^-like col- lection of hairy drupelets which is easily detached from the non- fleshy receptacle. The fruit is used in the prei)aration of syrup of raspberry which is used for flavoring. There are a inmiber of varieties of this species of raspberry in cultivation, the fruits of 564 A TEXT-BOOK OF BOTANY. which vary in color from crimson, brown, or yellow to nearly white. The fine flavored but watery fruit of the wild red-rasp- berry (R. strigosiis) is sometimes substituted for the fruit of Ruhus Idocus (Fig. 243). Rosa gallica, which yields the red rose-petals, official in a num- ber of the pharmacopoeias, is a native of Southern Europe and is extensively cultivated. Rosa centifolia, which is now known only in cultivation, and of which there are a large number of varieties, is distinguished by its glandular leaflets, and its pale red or pink petals. The cone-like collection of petals of the flower-bud is the part which is used in medicine, but it is deficient in coloring principles and fragrance as compared to Rosa gallica. Rosa damascena, the petals of which yield the oil of rose or attar of rose, is extensively cultivated in Bulgaria and to some extent in France and Germany. It flowers very profusely, and the yield of oil is about 0.02 per cent. The oil consists of a crys- tallizable hydrocarbon known as rose-camphor which is odorless, and a liquid portion consisting of geraniol, 1-citronellol, 1-lina- lool, citral, n-nonyllic aldehyde and phenyl ethyl alcohol. Similar oils are obtained from other species of Rosa growing in Northern Africa, Abyssinia and Northern India, as R. moschata, and R. sempervirens. The fruits of wild brier (Rosa canina) naturalized from Europe, as well as of other species of Rosa (R. pomifcra and R. rugosa), contain considerable malic and citric acids and fruit- sugars, and are made into a confection by boiling with syrup. In addition to the fruit-ethers found in the common edible fruits of this family and the volatile oil of rose, it should be mentioned that oils containing salicylic acid are also present. A number of species of Spiroca contain salicylic aldehyde and methyl salicylate. Quillaja Saponaria is a large tree having a thick bark and hard wood. The leaves are oval, coriaceous, slightly dentate and evergreen (Fig. 316). The flowers are monoecious or dioecious, white, apetalous, and axillary in groups of one to four. The ovary consists of 4 to 5 carpels and on ripening forms a star-like, spreading group of follicles. The inner bark is the part used in medicine. CLASSIFICATION OF ANGIOSPERMS. 565 A spurious quillaja bark (Q. Pocppigii) differs from tlie official in being thinner, darker and in having the surface covered with a coarse network of whitish Hues. Another bark, (jccurring in quilled pieces, from 8-15 cm. long, and 1-5 cm. wick-, lias also been found in commerce. Hagenia abyssinica is an ornamental tree witli 7- to 13-foliate leaves. The flowers are monoecious and occur in panicles ; the staminate being greenish-yellow and with 20 stamens ; and the pistillate fragrant, bicarpellary, and with a reddish calyx ( I^^ig. Pig. 316. Soap-bark t^ee (Quillaja Saponaria): A, flowering branch; B, one of the hermaphrodite flowers; C, the latter in longitudinal section. — After Baillon. 317). The fruit is a nutlet. The pistillate flowers are oftlcial under the name of Cusso. A arious species of Prunus yield gums, as cherry, peach, apricot, etc. Mucilage is found in the testa of certain seeds, as of quince. The manna of Luristan is obtained from Pynis (jlabra of Persia. Tannin and gallic acid are found in Tohmkxtiula rhizome which is' obtained from Potcntilla silvcstvis, a perennial herb of Europe, and other species of Potentilla. Tlic fruit of ilic hawthorn {Cratccgus OxyacantJia) contains quercitrin. A bitter principle and tannin are found in Piirsliia trident at a of the Rocky Mountains. Phloridzin is found in the root bark of a number of species of Pyriis and Prunus. S66 A TEXT-BOOK OF BOTANY. Fig. 317. Hagenia abyssinica: A, branch showing a large panicle of pistillate flowers and the stipulate, compound leaves; B, C, staminate flowers; D, E, pistillate flowers. — After Berg and Schmidt. In the genus' Fragaria to which the strawberry belongs, the torus becomes large and fleshy and is the edible part of the fruit. The garden strawberry (F. chilocnsis) has a large fruit, the achenes being sunken in the periphery of the torus (Fig. 242). In CLASSIFICATION OF ANGIOSPERMS. 567 the wild strawberries the fruit is smaller, usually somewhat flesh- colored and the achenes are either embedded in the torus as in I\ virginiana or borne on the surface as in F. vesca. Tlie strawberry fruit contains about 87 per cent, of water; 6 per cent, (jf cane sugar; 5 per cent, of invert sugar (a mixture of dextrose and levulose) ; i per cent, of free fruit-acids; and about 2 per cent, of nitrogenous substances. g. LEGUMINOS^ OR PULSE FAMILY.— The plants are herbs, shrubs, trees, or vines with alternate, stipulate and usually compound leaves. The flowers are complete, and the corolla is either regular or irregular; the stamens are usually united, and the pistil is simple and free, becoming in fruit a legume. The plants are widely distributed, many of them being found in the Tropics. Three principal sub-groups, which have been ranked as families by some botanists, are recognized. 1. PapilionattE. — Those species with papilionaceous flowers are separated into a group called the Papilionatae. This sub-grouj) has a number of representatives in the United States, as clover, locust, and Baptisia (Fig. 280, L). 2. C.^SALPiNioiDE.E iuclude the sennas and have flowers which are nearly regulai', or imperfectly, or not at all papilionaceous. 3. The MiMOSOiDE.E include the acacias and have flowers tliat are regular. Cassia acutifolia is a small shrub with leaves that are 8- to lo-foliate. The leaflets are official as Alexandria or Tripoli senna ; the flowers are yellowish and in axillary racemes; the fruit is a smooth, flat, dehiscent pod, with 6 to 8 seeds. Cassia angustifolia is a shrub which is cultivated in Southern India and resembles Cassia acutifolia. The leaflets which consti- tute India senna or Tinnevelly senna are longer and narrow-lanceo- late, and the pods are longer, and slightly crescent-shaped, as compared to those of C. acutifolia. Cassia Fistula or purging cassia, the pods of w^hich are used in medicine, is a tree about 15 J\I. high. The leaves are 10- to 12- foliate ; the flowers golden-yellow and in racemes ; and the fruit is a very long, cylindrical, indehiscent legume. The leaves of quite a number of species of Cassia are used in medicine and the '568 A TEXT-BOOK OF BOTANY. following are the source of Folia Malabathri : C. Tamala of Assam and C. javanica. Glycyrrhiza r/Iabra is a perennial herb, with 8- to 14-foliate Fig. 318. Spanish licorice (Glycyrrhiza glabra) plant grown from a cutting by the late Henry N. Rittenhouse of Philadelphia. leaves (Fig. 318), the leaflets being glandular in the variety glandulifera; the flowers have a violet-colored, papilionaceous corolla, and the fruit is a flat, dehiscent legume. The rhizome and roots are the parts used in medicine. CLASSIFICATION OF ANGIOSPERMS. 569 Cytisus scoparius or green or Scotch broom is a shrub nat- uraHzed from Europe. The branches are numerous, slender, erect and grow close together, adapting them for use as brooms. The tops are used in medicine. Tamarindus indica is a tree attaining a height of 25 M. The leaves are pinnately compound, having numerous sessile, entire, Fig. 319. Tragacanth plant (Astragalus gummifer): A, flowering branch; B. modified, thorn-like leaf with stipules at the base; C, irregular (bilateral) flower; D, legume of .4. aristatiis. — After Taubert. oblong leaflets ; the flowers are in terminal racemes and the petals are yellow with reddish veins ; the fruit is a curved, indehiscent legume which has a thin epicarp and a pulpy sarcocarp with numerous fibers, and contains a number of flat, quadrangular seeds. The pulp is the part used in medicine as a laxative and refrigerant. Astragalus gummifer is a tomentose shrub less than i ^I. high. The leaves are pinnately compound, the leaflets being narrow 5/0 A TEXT-BOOK OF BOTANY. and elliptical ; the flowers are pale yellow, sessile and axillary ; the fruit is a small, somewhat cylindrical, hairy pod or legume. The gummy exudation constitutes the Tragacanth of commerce. Acacia Senegal, which yields gum Arabic or acacia gum, is a small tree with bipinnate leaves which are subtended by curved spines ; the flowers are yellow and in dense spikes ; the fruit is a broad pod containing five or six seeds. Acacia Catechu is a small tree which resembles Acacia Senegal and furnishes Black Catechu. Fig. 320. Acacia Senegal: A, flowering branch; B, a single flower showing numerous stamens; C, part of legume showing attachment of seeds; D, E, sections of seeds.— Af cer Taubert. Pterocarpus Marsupium is a fine timber tree with spreading branches. The leaves are 5- to 7-foliate, the leaflets being cori- aceous, obovate, and emarginate ; the flowers are pale yellow, and the fruit is an indehiscent, orbicular pod with a single reniform seed. The ofiicial Kino is prepared from the juice. The trees yielding kino are under State control in Madras. According to v. Hohnel the kino is present in special cells in the bark, which are arranged in radial rows in the region of the lep- tome. The cells are from 50 to 100 /x wide and from 100 to GLASSIFICATIOX OF AXGIOSPERMS. 5/1 500 ;a long, the walls consisting of cellulose. The teiin " kinu " is applied to the red astringent juices obtained from a number n{ plants. " American kino " is a synonym sometimes applied to the extract of Geranium maculatuni (h'am, GeraniacccC ). Pterocarpus santaliniis is a small tree with trifoliate leaves, and flowers and fruits resembling those of P. Marsiipiuui. The heart-wood is official. Hccmatoxylon campechianum is a small tree with irregular spinous branches. The leaves are 8- to lo-foliate, the leaflets being sessile and obcordate. The flowers are fragrant, have a purple calyx and yellow corolla, and are in racemes. The fruit is a slender, lanceolate, flat pod, which dehisces laterally instead of along the sutures. The heart-wood of this tree constitutes the commercial Logwood, of which about 200,000 pounds are con- sumed annually, its chief use being as a dye-wood. Kramer ia triandra is a shrub with a few, simple, ovate-lanceo- late, sessile, silver-white, glistening leaves. The flowers are com- plete, having two purple petals and three stamens. The fruit is a f-seeded, globular, prickly, indehiscent pod. K. Ixina, found growing from Mexico to Northern South America, and K. argen- tea of Northern Brazil, are distinguished by having flowers with three petals and four stamens. The root is the part used in medicine. Copaiba Langsdorffii is a small tree found growing in Brazil. The leaves are 6- to lo-foliate, the leaflets being ovate-lanceolate, glabrous, coriaceous, and glandular punctate. The flowers are apetalous, and the fruit is an ellipsoidal, coriaceous, 2-valve(l pod having a single glandular seed with an arillus. An oleo-resin collects in longitudinal cavities in the trunk of the tree, often amounting to many liters, and sometimes the pressure thus pro- duced is sufficient to burst the trunk in places. The oleo-resin is official as Copaiba. The latter consists of 30 to 75 per cent, of a volatile oil from which the sesquiterpene caryophyllene has been isolated ; a bitter acrid resin and a bitter principle. A similar prod- uct is obtained from a number of other species of Cojiaiba growing in South America, as well as C. copallifcra of Western Africa, and Hardwickia Mannii of tropical Africa, and //. pinnata of India. An oleo-resin known by the natives in the province of Velasco S72 A TEXT-BOOK OF BOTAXY. in Bolivia as " Copaiba " is obtained from Copaiba paupera. It is thick, like Maracaibo balsam, but lighter in color and resembles in odor and taste true copaiba. It is distinguished from the other specimens of American copaiba by its dextro-rotation [a]D -f 36°. On the addition of one to two volumes of petroleum ether it forms a clear solution, giving a white precipitate on the addition of more ether. Toluifera Balsamum is a tree about 25 ]M. liigh. with a straight trunk, on which the branches first appear at a height of from 15 to 20 M., and is found growing in Northern South America. The leaves are compound and with seven to eleven alternate, oblong, acuminate, glandular-punctate leaflets ; the flowers are white and in simple axillary racemes ; the fruit is a winged, inde- hiscent, i -seeded legume. The plants yield a balsam (official in all the pharmacopoeias and known as Balsam of Tolu) which occurs in schizogenous cavities in the bark of young twigs, and is obtained by incising the bark, it being usually collected in gourds. The balsam consists of 75 to 80 per cent, of resin, which is a compound of tolu-resinotannol, cinnamic and benzoic acids; 18 to 20 per cent, of free cinnamic acid; 0.2 to i per cent, of a volatile oil; and 0.5 per cent, of vanillin. A good tolu balsam is also obtained from T. peniifera growing in the northeastern part of South America. Toluifera Pereircc is a tree about 15 j\I. high, which has a short trunk and begins to branch at a height of 2 or 3 M. It otherwise resembles T, Balsaniiiiu. It is found over the whole of Northern South America, extending through Central America to Alexico, and is cultivated in Singapore. The balsam, which is formed as a result of injury to the trunk, consists chiefly of esters of benzoic and cinnamic acids, some free cinnamic acid, and vanil- lin. A very fragrant vanilla-like balsam is obtained from the fruit of this same plant, and in San Salvador it is known as white Peru balsam to distinguish it from the black Peru balsam obtained from the trunk. Physostigma venenosum is a woody climber. The leaves are 3-foliate, the leaflets being ovate -acuminate ; the flowers are violet in color and in axillary racemes ; the fruit is a broadly linear, somewhat flattened, distinctly veined, dehiscent pod which tapers CLASSIFICATION OF ANGIOSPFRMS. 573 s two or three seeds. The .eeds at both ends, and usually contani are official as Physostigma. possessing nearly sessile 6 i coloring principle has oeen racemes of yellow flowers A P^J^^^^ inferior.-After Brown. resembling indigo, though somewha obtaiucd frOUl The blue coloring principle ^^^;^^^ ^^ "^.^^^^h are indigenous the herbs Indigofera Unctona and /. Ami 574 A TEXT-BOOK OF BOTANY. to, and cultivated in, tropical and sub-tropical countries. It is prepared by extracting the leaves with water. The glucosidal principle indican (or mother-substance of indigo blue) undergoes oxidation and the insoluble indigo blue separates out. This is the commercial indigo. A similar principle is found in the wild indigo (Baptisia tinctoria) of the United States and Canada; the leaves of Robinia Pseud-acacia of North America ; several species of Psoralea and Amorpha, as well as some other Leguminos^e. It is also found in other families, as in Polygonaceae, Cruciferae, Ascle- piadaceae, and Apocynacese. A yellow coloring principle is found in the dyer's broom (Genista tinctoria) of Europe and Asia and naturalized in the New England States. G. ovata of Europe yields a similar dye. Copal Resins are derived from a number of the Leguminosae : American copal from Hymejura Coubaril of the West Indies and South America ; Brazilian copal from H. Martiana of Rio Negro ; Zanzibar or Chakazzi-copal from Tracliylobium nwsambiccv.se of Western Africa; Sierra Leone copal (yellow gum, red gum) from Copaiba Guibourtia of Sierra Leone ; Inhambane copal from Co- paiba conjugata and C. Gorskiana of Singapore, Jamaica and Australia. A number of the loco- weeds containing principles poisonous to cattle belong to the Leguminosae. The word " loco," meaning crazy, is of Spanish origin, and is applied in reference to the pecu- liar nervous symptoms manifested by the afifected animals. The plants causing greater loss than all other poisonous plants com- bined and regarded as loco-plants par excellence are Aragalliis Lamberti and Astragalus mollissimus. Of these two Aragalliis Lamberti, also commonly known as rattleweed or white loco, is the most poisonous and has a wide range, extending from Alaska on the north down through the whole grazing region of the Great Plains, where it is very abundant. Astragalus rnollissimus, known as purple loco, woolly loco, or Texas loco, is more limited in its range. Among other plants causing heavy losses to stockmen on the grazing lands of the Great Plains east of the Rocky Mountains may be mentioned the following: Zygadenus elegans (Fam. Lili- acese), especially dangerous to sheep ; the larkspurs or Delphiniums (Fam. Ranunculaceae), causing losses among cattle; and lupines, CLASSIFICATION OF ANGIOSPERMS. 575 causing losses especially among sheep. The water hemlock (Cicuta maculata, Fam. Umbelliferse) is poisonous to all higher animals, including man. Among other plants poisonous to cattle the following may be mentioned: California loco-weed (Astrag- alus Crotalaricu), Texas or woolly loco-weed {A. mollissimus), rattle-box {Crotalaria sagittalis) found in the Eastern United States and Canada. The poisonous action of some of these plants has been ascribed to the presence of barium salts, although this has not been substantiated in all cases. Clitoria glycinoidcs of Brazil and Phaca ochroleiica of Chile are poisonous to horses and should probably be included with the loco-weeds. A large number of the plants belonging to the Leguminoss contain toxic principles and those which have not already been considered might be grouped according to the principles which they contain. 1. Arrow-poison group, including the genera Erythrophloeum, Afzelia and Pithecolobium. 2. FiSH-POisoN group, including the genera Albizzia, Afzelia, Bauhinia, Barbiera, Enterolobium, Leucsena, JMillettia, Tephrosia, Acacia, Abrus, Clitoria, Mundulea, Derris, Lonchocarpus, Pisci- dia (F. Erythrina or Jamaica dogwood, which contains a curare- like alkaloid). 3. SAPONiN-containing plants as the genera Acacia, Albizzia, Entada (E. scandens or the sea bean of the East and West Indies), Enterolobium, Gleditsia and Gymnocladus {G. dioica or Ken- tucky coffee-tree growing in the United States and Canada). 4. CvTisiNE-containing plants ; the alkaloid cytisine is found in Laburnum vulgare and L. alpinum growing wild in Southern Europe and also cultivated, and in one or more species of the following genera : Anagyris, Baptisia, Coronilla, Crotalaria, Genista, and Ulex. Abrin, composed of a globulin and albumose and whose prop- erties are affected at a temperature of 50° C. or over, is found in the seeds of Jequirity (Abrus precatorius) and Cassia hispidula of Mexico; two alkaloids (lupinine and lupinidine) and a bitter glucoside (lupinin) are found in the white lupine {Liipinus albus) of Europe and in other species of Lupinus ; a glucoside (wistarin) and a poisonous resin are found in Wistaria, species of IVistcria, 576 A TEXT-BOOK OF BOTANY. a common woody climber in cultivation as an ornamental plant ; the glucoside ononin is found in Radix Onoxidis, the root of Ononis spinosa of Europe; the glandular hairs on the pods of Mucuna pniriciis and M. livens growing in the Tropics of both hemispheres constitute the cowhage of medicine ; butyric acid is found in St. John's bread, the fruit of Ccratonia Siliqua, which growls in "European countries bordering the Mediterranean, and also in Epcrua falcata of Guiana. A bitter principle, bondicine, known as poor man's quinine, is found in Cccsalpinia Bonducella and other species of Ccrsalpinia growing in Sumatra, Borneo, New Zealand and Brazil ; the seeds of Phaseolus lunatus of the East Indies contain a principle from which hydrocyanic acid is derived. The seeds of many of the plants belonging to the Leguminosse are rich in starch and proteins and hence are used as foods. The protein legumin is characteristic of this family. The following are some of the important food plants: the garden pea {Pisum sativmn), the garden bean {Phaseolus vulgaris) ; lentil {Lens esculenta), Japanese Soy bean {Glycine hispida). The peanut {Arachis hypogcca) indigenous to Brazil and extensively culti- vated in most of the Southern States and in Southern Europe, belongs to the group of plants which have geocarpic fruits, that is, fruits which penetrate the soil during their development and ripen under ground (Fig. 231). In peanuts the starch is re- placed by a fixed oil which is present to the extent of about 45. per cent, and which is an article of commerce. In addition to the seeds mentioned those of a number of other plants as well as some fruits, roots and leaves are used as foods in various parts of the world, particularly in the Tropics. The plants of a number of species are used as forage, as those of clover {Trifolium) ; some are cultivated as ornamental plants, as sweet pea {Lathy r us odoratns), and some yield valuable timber, as the locust {Robinia). Soy Bean {Glycine hispida) is an important food plant and forage crop. The plant is an annual with trifoliate hairy leaves, rather inconspicuous pale or violet-colored flowers, and with broad pods containing 2 to 5 seeds. The seeds are more or less com- pressed, spherical or elliptical and vary in color from whitish- or yellowish-green to brownish-black. The yield of seed per CLASSIFICATION OF ANGIOSPERMS. z.-j-j acre may run as high as 40 bushels. As a furage crop it yields as high as 2 to 3 tons of cured hay per acre. The seeds contain about 5 per cent, of starch and nearly 50 per cent, protein sub- stances. The seeds are therefore very nutritive and are exten- sively used in feeding of live stock. In Jai)an the seeds are known as " Soy," being derived from the Japanese word *' Shoyu," in allusion to a preparation made from the seeds. In Furope it is also used to a limited extent as a food. In this country it is used to some extent as a food for persons sufifering from diabetes. Alfalfa or Lucerne (Mcdicago sativa) is one of the most \al- uable forage plants known to man. It is a i)erennial herb w itii obovate-oblong leaves, bluish purple flowers occurring in racemes, and twisted pods. Alfalfa is extensively cultivated in all parts of the Lnited States. It is an exceptionally deep-rooted leguminous plant and under the best conditions is long lived, growing in the arid lands of the West as well as in the rich soils of the East. In many essentials and in feeding for stock alfalfa resembles the clover. The alfalfa is relatively somewhat richer in digestible protein than the clover but considerably lower in fat. Vegetable Bezoars are concretions formed in the stomachs of ruminating animals. They consist of the hairs of crimson clover and the awns of oats, barley and other cereal grains. They are spherical in shape, of a yellowish-brown color, with smooth, even surfaces, of a firm texture, and saturated with intestinal juices. The balls when dried shrink but little and vary from 10 to 12 cm. in diameter. Since the introduction into the L^nited States of crimson clover as a forage plant or green manure, there have been numerous deaths reported among horses and other cattle due to their eating crimson clover, which leads to the formation of bezoars caused by the undigested hairs matting together. An examination of these bezoars shows that the hairs of which they are composed, lie with the broken or basal end toward the center of the ball, the sharp simimit being directed toward the surface. XVL ORDER r.ERAXLVLES. This order includes a number of families of economic impor- tance. The sepals are mostly distinct; the stamens are few; the carpels are united, and the ovules are pendulous (epitropous). 37 578 A TEXT-BOOK OF BOTANY. a. GERANIACE^ OR GERANIUM FAMILY.— The plants are herbs with alternate or opposite, usually stipulate leaves, regular and perfect flowers, and capsular fruit (Fig. 236, C). Geranium maculatuin is a perennial herb (Fig. 322) with a short, thick, horizontal rhizome, from which arises a simple, some- FiG. 322. Geranium maculatum showing typical dicotyledonous flowers and the s-parted, reticulately-veined leaves. what branching, hairy stem, with 3- to 5-parted, variously toothea and cleft, petiolate leaves, those on the upper part of the stem being opposite; the flowers are regular and 5-merous, occurring singly or in twos in the axils of the leaves ; the petals are rose- purple and hairy at the base ; the fruit is a dehiscent capsule ; the CLASSIFICATION OF ANGIOSPERMS. 579 five carpels when ripe separate and roll upwards, remaining attached to a central column by means of a slender carpopliore, the individual carpels being in the nature of achcncs. Tlic rliizonie is the portion used in medicine. The cultivated geraniums belong to the genus I'elar^omuni, and some of the species furnish oil of rose geranium, as P. udora- tissimum, P. capitatum and P. Radiila, all of which are cultivated in France, Spain, Germany, Algiers and Reunion for the oil, whicli is largely used in perfumery. The oil contains geraniol, cit- ronellol, and various esters. The leaves of Pelargonium pcltatiim, growing in certain parts of Africa and Australia, contain oxalic acid and acid oxalates. b. OXALIDACE.F. OR WOOD-SORREL FAMILY.— To this family belongs the genus Oxalis, some species of which have leaves that are quite sensitive to light as well as mechanical stimuli, which applies especially to the cultivated forms of South Africa, and to the common wood-sorrel (Oxalis Acetosella)^ of the United States and Canada, as well. The leaves contain oxalic acid and acid oxalates. c. THE TROP^OLACE/E OR NASTURTIUM FAMILY comprises but a single genus, Tropaeolum. Some species are culti- vated for ornamental purposes and are the nasturtiums of the garden. The young shoots are succulent and taste like some of the cresses, hence they have received the name " Indian cress." They contain volatile constituents resembling those of the Cruci- ferae, and in the leaves of Tropccoliim niajus benzyl mustard-oil is found. The flower-buds and young fruits of this species are used for pickling like capers. d. LINAGES OR FLAX FAMILY.— The most important plant of this family is the common flax {Liniuii iisitatissinnon). This is an erect, slightly branching annual herb with alternate, lanceolate and 3-nerved leaves. The flowers are in terminal, leafy panicles, the pedicels being slender, the calyx non-glandular, and the petals blue (Fig. 280 A). The fruit is a lo-locular, lo-seeded capsule. The seeds are official. There are a number of culti\ated varieties and the seeds of the z'ar. hiunilc contain a glucoside which yields, under the influence of ferments, hydrocyanic acid. A cathartic principle has been found in L. catJiarticiini ^n'owing in 58o A TEXT-BOOK^ OF BOTANY. Europe. The bast fibers of Linum usitatissiiuum are used in the manufacture of hnen. These fibers are distinguished from many other vegetable fibers in not containing lignin. e. ERYTHROXYLACE^ OR COCA FAMILY.— This family contains but two genera, one of which is Erythroxylon. Fig. 323. Flowenng branch of Erythroxylon Coca showing the parallel lines on either side of the midrib, which are not true veins, but due to an extra development of hypodernial cells in this region. — After Reiche. The official coca leaves (Fig. 323) are obtained from Erythroxy- lon Coca. The plant is a shrub and requires a very humid atmos- phere and a comparatively high elevation. The leaves are alternate, petiolate and entire; the flowers are white and very small ; the fruit is a reddish drupe resembling that of dogwood. Coca leaves contain several alkaloids, including cocaine, cinna- CLASSIFICATIOxX OF AXGIOSrKRMS. 581 myl-cocaine, truxilline and ccgonine. Of llicsc cocaine is ihc most important, the Bolivian leaves containing the greatest amount, or 0.5 to I per cent. ; the other alkaloids preponderate in tiie Peruvian leaves, which usually do not contain more than one-half or two- thirds as much cocaine as the Bolivian leaves ; the Java leaves also contain benzoyl-pseudotropine ; in addition, coca leaves contain a volatile aromatic principle ; and a tannin giving a green color with ferric salts. Cocaine (benzoyl-methyl-ecgonine) occurs in monoclinic prisms. The hydrochloride of cocaine with palladous chloride forms a characteristic crystalline double salt (Fig. 97). Other species of Erythroxylon also yield useful products. An aromatic oil is found in the wood of E. iuonogynum of Ceylon and India, and the wood is known as '' bastard cedar " or '* Ijastard santal.'' A brownish-red coloring principle is found in the red- wood (E. (crolatum) of Jamaica and in E. siibcrosiim and E. tortuosum. Purgative and anthelmintic principles are found in some species of this genus. /. ZYGOPHYLLACE^ OR CALTROP FAMILY.— The plants are mostly herbs and shrubs which are widely distributed in warm-tropical regions. The leaves are mostly opposite, pin- nate and stipulate. The genus Giiaiacum is of interest on account of the wood containing considerable resin, which is used in medicine. Guaiacuin officinale is a small tree with 4- to 6- foliate leaves, the leaflets being ovate, entire and sessile ; the flowers are large, blue, and in axillary clusters ; and the fruit is a 2-valved capsule (Fig. 324). G. sanctum is a tree resembling G. oflicinalc, but is distinguished by having leaves which are 8- foliate and with smaller leaflets, and a 4- to 5-valved capsule. The resin of both species is official. A resin having an odor resembling that of creosote occurs in the CREOSOTE BUSH (GovUIca tridcntata) of ^Mexico and Texas. The juice of Peganum Harmala contains a yellow coloring principle used in dyeing. A number of the ])lants of this family contain powerful poisonous principles. g. RUTACE^ OR RUE FAMILY.— The plants are shrubs or trees, seldom herbs, with lysigenous oil-secretion cells. The 582 A TEXT-BOOK OF BOTANY. leaves are usually alternate, simple or compound and glandular- punctate (Fig. 280, C). Xanthoxylum americanum or northern prickly ash is a shrub or small tree with 5- to ii-compound leaves, the leaflets being ovate and nearly sessile ; the flowers are dioecious, greenish, and in axillary cymes ; the fruit is a black, 2-valved capsule. A'. Clava- Herculis or the southern prickly ash is a very prickly shrub, which Fig. 324. Guaiacum officinale: A, flowering and fruiting branch; B, gynaecium in longitudinal section showing the pendulous ovules; C, a seed; D, E, the fruit in longitudinal and transverse sections. — After Berg and Schmidt. is characterized by having cork-wings on the bark. The leaves are 5- to 17-foliate, the leaflets being ovate and crenulate ; the flowers are in terminal racemes and have a calyx of 4 or 5 sepals, the calyx being wanting in X. americanum. The bark of these two species is official. Pilocarpus. — To this genus belong a number of species which are shrubs or small trees and indigenous to tropical America. The leaves are mostly pinnately-compound, the leaflets being coriaceous and entire ; the flowers are small, greenish and in axillary or terminal racemes ; the fruit is a i-seeded, 2-valved CLASSIFICATION OF ANGIOSPERMS. 583 capsule. The leaves of three species are ofhcial as Pilocarpus or Jaborandi. Barosma. — The buchu leaves of medicine are obtained from several species of Barosma (see Vol. II). The plants are branch- ing shrubs with opposite, coriaceous, serrate or dentate leaves with glandular margins ; the flowers are white or reddish and occur, I to 3, in the axils of the leaves; the fruit is a 5-valved capsule. The leaves contain a volatile oil, one of the constituents of which is diosphenol. Citrus. — The fruits of a number of species of this genus are edible, and the plants are also valued for their volatile oils. They are aromatic, glandular, mostly thorny shrubs or small trees indigenous to tropical and sub-tropical Asia, and now extensively cultivated in tropical, sub-tropical and warm-temperate regions. The leaves are more or less winged-petiolate, glaucous, coria- ceous, mainly unifoliate (or trifoliate) ; the flowers are complete, with a 3- to 6-toothed gamosepalous calyx, and 4 to- 8 glandular petals ; the stamens are 20 to 60, in groups of i to 9 ; the ovary is subtended by a cushion-shaped disk, and the fruit is a spher- ical, oblong or pear-shaped berry, having a coriaceous pericarp with numerous lysigenous oil-glands, a juicy pulp made up of peculiar hair-structures which arise from the endocarp, and in which are embedded white polyembryonic seeds (Fig. 280, C). Botanists have divided this genus into two sub-groups: (a) the Pseudo-^gle group is represented by the trifoliate orange (Citrus trifoliata), cultivated widely in the United States as a hedge. The leaves are trifoliate and deciduous, the petals spatu- late and the ovary and disk hairy, {b) In the Eucitrus group the leaves are unifoliate and evergreen, the petals oblong, and the ovary and disk glabrous. This latter group includes the two species which yield most of the edible Citrus fruits. Citrus Aurantiiun includes a number of sub-species and varie- ties. The plants are small trees with leaves having winged petioles ; fragrant, white flowers ; and a more or less globular fruit. The Sweet Orange (Malta, Portugal) is derived from the sub-species sinensis. The Bitter Orange (Seville, Curasao) is derived from the sub-species auiara. The flowers of both the Sweet and Bitter Orange tree contain a volatile oil known as Oil 584 A TEXT-BOOK OF BOTANY. OF Neroli, and composed of limonene, geraniol, linalool, etc. The oil from the rind of the fruit is known as oil of orange peel, and is obtained chiefly from Italy and Sicily. It is composed of limonene, citral, citronellol, etc. The oil from the Bitter Orange peel has a superior flavor and is known as Bigaradl\ oil. The Bergamot Orange is the fruit of the sub-species Bergamia, culti- vated in Europe, but only rarely in the United States. The oil of the rind of the fruit is known as Bergamot oil and consists largely of linalyl acetate. In the group of Mandarin or Kid- glove orange (Citrus nohilis) the fruit is compressed, spherical, 5-6 cm. in diameter and with an orange-yellow, loose and easily removable rind. The shaddock or grape-fruit is derived from the sub-species sinensis var. deciimana, a tree indigenous to ithe Malay Archipelago and extensively cultivated in India, Flor- ida, California and elsewhere. The fruits are quite large, some- times weighing several kilograms, and those which are round are the most valuable commercially, being known as Pomelos or Grape-fruits. The Blood Orange is the fruit of the sub-species sinensis var. sanguinea. The Otaheite Orange, which is ex- tensively cultivated as a dwarf pot plant and the foliage and flowers of which resemble those of lemon, is probably a variety of the sub-species sinensis, or it may be a hybrid of lemon and orange. The Navel Orange is a sweet orange in which an additional compound ovary is developed within the fruit. Lemon and lime fruits are derived from sub-species of Citrus medica, which are mostly shrubs with simple, petiolate leaves, reddish twigs and flowers, and more or less ellipsoidal fruits. Lemons are derived from the sub-species Limonum. The rind of the fruit yields the oil of lemon, which consists of limonene, citral, etc. Most of the commercial article comes from Sicily and Calabria. Lime fruits or limes are derived from the sub-species acida, a shrub cultivated in the West Indies and Florida. The Citron fruit, the rind of which is used in the making of preserves and confections, is derived from the sub-species genuina. The fruit is large and lemon-like but with a thick rind, the plant being cultivated to some extent in Florida and California. The Kumquat Orange is obtained from Citrus japoniea, a thornless tr^e with spreading dwarf habit extensively cultivated CLASSIFICATION OF ANGIOSPERMS. 585 in China and Japan and very hardy even in Northern I'lorida. The fruit is round or oblong, from 3 to 5 cm. long- and 2 to 3 cm. in diameter, and of an orange-yellow color; the rind is sweet, while the pulp is acid, and usually free from seeds, although from I to 4 slightly beaked seeds may be present. The inner white portion of the rind of the Citrus fruits con- tains a crystalline, tasteless glucoside known as hesperidin (see pp. 151-154). Those which are bitter contam in addition several bitter glucosides, namely, aurantiamarin and naringin. (See Aurantii Amari Cortex, and Aurantii Dulcis Cortex, in \'ol. II.) \^olatile oils are also found in other members of the Rutaceae. The garden rue (Ruta graveolens) , the leaves of which are used in medicine, contains a volatile oil consisting of several ketones. It also contains a glucoside known as rutin which resembles the barosmin of buchu ; and quercetin, which is said to be derived from rutin. The Hop tree (Ptelea trifoliata) of Eastern North Amer- ica contains besides a volatile oil, a resin and an alkaloid. The volatile oil of pepper-moor (Zanthoxyhim piperitimi) of China and Japan is known as Japanese oil of pepper. Angustura bark obtained from Ciisparia trifoliata or C. oiHcinalis, plants growing in the region of the Orinoco River, con- tains a volatile oil, resin, a bitter principle and four alkaloids. The v^ood of Amyris balsamifera of Guiana and Jamaica, yields on distillation a volatile oil resembling Oleum Rhodii. h. SIMARUBACE^ OR AILANTHUS FAiMILY.— The plants are chiefly shrubs or trees with alternate and pinnately- compound leaves. The flowers are regular, dioecious or polyg- amous and in axillary racemes. The plants are natives of tropical countries and are distinguished from the Rutacese, which they somewhat resemble by the absence of oil secretory cavities. They are widely employed particularly in the tropics, on account of their bitter principles, and are considered valuable tonics, febrifuges and remedies for dysentery. Picrasma excclsa is a small tree with 9- to 17- foliate leaves, the leaflets being ovate and more or less tomentose, particularly in the bud ; the flowers are yellow, polygamous and in axillary panicles ; the fruit is a large, spherical drupe. The wood of the plant constitutes Jamaica quassia. 586 A TEXT-BOOK OF BOTANY. . Quassia amara is a small tree or shrub with 4- to 5-foliate leaves ; the leaflets are narrow, obovate and acuminate, and the rachis and petiole or stalk are winged; the flowers are her- maphrodite, with 10 stamens, bright red corolla, and in terminal racemes ; the fruit is a 5-valved indehiscent pod or nutlet. The wood constitutes Surinam quassia. A red coloring principle is found in Samadera indica of India, Ceylon and Java. The alkaloid cedronin is found in the seeds of Simaha Cedron of New Granada, the seeds being used as an anti- dote for the bites of poisonous animals. A similar principle may exist in the bark of Simaruha versicolor of Brazil, the plant being used for a similar purpose. The alkaloid brucamarine is found in the fruit of Brucea sumatrana. A tragacanth-like gum is obtained from AilantJius excclsa of India. Dika or.GABUN Choc- olate is obtained from the seeds of Irvingia gabonensis of trop- ical West Africa. Cay-Cay-Butter is obtained from the seeds of Irvingia Oliveri and /. malayana of Malacca and Cochin China. A gum resembling acacia is also obtained from the bark, peti- oles and seeds of the species of Irvingia. i. BURSERACE^ OR MYRRH FAMILY.— The plants are shrubs or trees, the latter being sometimes quite large, with resin-canals in the bark, and alternate compound leaves ; the flowers are small, occurring in racemes. The members of this family are found in tropical countries. Commiphora abyssinica is a shrub 10 M. high, the branches being modified to thorns ; the leaves are trifoliate, the leaflets being oblong, dentate, 'sessile and the terminal one much larger than the other two ; the flowers are dioecious, and the fruit is a drupe with a fleshy, resinous sarcocarp. The official Myrrh is probably obtained from this plant as well as other species of Commiphora. A number of other resinous products are yielded by plants of this family. West India Elemi resin or Elemi Occidentale (Anime) is obtained from the stems of Protiiim Icicariba of Brazil. The resin is greenish-yellow, soft, with a bitter taste and dill-like odor. Manila Elemi is a soft, granular, lemon-yellow or grayish-white resin derived from Canarium commune of the Philippine Islands. Bengal Elemi is derived from Commiphora Agallocha of the East Indies and Madagascar. The Tacamahac CLASSIFICATlOxN OF ANGIOSPERMS. 587 Resins are balsamic resins, of which there are several comnicrcial varieties: Mauritius tacamahaca is obtained from Protiiim hcpta- phyllmn of Columbia, and Mexican or West Indian tacamahaca from Bursera tomentosa of Mexico, West Indies, and South America. India Bdellium is a resin obtained from tlie bark of Commiphora Roxburyhiana of Northwestern India and Belu- FiG. 325. Myrrh plant {Commiphora abyssinica): A, young branch showing tri- foliate leaves; B, flowering and fruiting stem with thorn-like branches; C, leaf axis in which occur a fruit and staminate and pistillate flowers; D, staminate flower in longitudinal section; E, longitudinal section of pistillate flower; F, longitudinal section of fruit showing arillus-like mesocarp and the easily dehiscent endocarp. — After Engler. chistan. CoPAL-like resins are obtained from Canariuni boi- galense (East Indian Copal) and possibly several species of Bur- sera. Black Dammar resin is obtained from Canariion ros- tratum of the Molucca Islands. Olibanum or Frankincense is a gum-resin obtained from several species of Boswcllia of Asia and Somaliland. American Olibanum or Soft Resin of Cayenne exudes spontaneously from the stems of Protiiim hcptaphyllum and P. giiianense. Gilead Balsam is obtained from Protium 588 A TEXT-BOOK OF BOTANY. altissimum and P. Carana of Guiana and Brazil. ^Mexican Lin- ALCE Oil is obtained from Bnrsera graveolcns, and several species of Bnrsera of Mexico are used as a substitute for Aloe wood. /. MELIACEvE OR MAHOGANY FAMILY.— This is a large family of tropical trees and shrubs with mostly alternate, compound and exstipulate leaves, the leaflets being entire, with secretion cells, but not glandular-punctate (Fig. 326). The flowers Fig. 326. Pride of China (Melia Azedarach) : A, flowering branch; B, a part of the inflorescence. — After Harms. are complete, the filaments being united into a tube ; and they occur in axillary clusters or racemes ; the fruit is a capsule, berry or drupe ; the seeds are sometimes wanged and with fleshy or leaf- like cotyledons. The bitter principle mangrovin is found in the bark of the China Tree or Pride of China (Melia Azedarach) indigenous to Asia, and extensively cultivated in tropical and warm-temperate regions, and naturalized in the southern part of the United States (Fig. 326). A similar principle is found in other plants of this family. CLASSIFICATION OF ANGIOSPERMS. 589 Carapa Oil, which has a characteristic odor an.' ^'^£-'5^t^:^^ ■BSPy,3MMMgI!Z3l ., I '^■^^^mmims ?^ms Etfffira Fig. 336. Cacao tree (Theobroma Cacao), growing in Rio Hondo, Costa Rica. In the illustration is shown the pecuUar habit of this tree in producing large, ovoid, fleshy fruits on the main axis or trunk, as well as on the older branches. When Cortez conquered Mexico he found the Aztecs using Cacao seeds to make a beverage; this was later introduced into Europe, previous to either coflFee or tea. — Reproduced by permission of The Phila- delphia Commercial Museum. A TEXT-BOOK OF BOTANY Fig. 337. A flowering branch of the Kola nut tree (Cola acuminata) , growing in Trini- dad. The leaves are obovate or lanceolate, acuminate, and in the axils are borne small clusters of purplish flowers. The tree is indigenous to Africa and is extensively cultivated in the West Indies and Brazil, in which countries it has become naturalized. — Reproduced by permission of The Philadelphia Commercial Museum. CLASSIFICATION OF ANGIOSPERMS. 615 Most of the cacao of the market is obtained from Ecuador (the Guayaquil variety being especially valued), Curasao, Mexico, Trinidad, and the Philippine Islands. The seeds of the wilc^ plants contain a bitter principle, the quantity of which is found to be greatly reduced in the plants when under cultivation. The bitter principles in the raw product are more or less destroyed by the process of fermentation to which the seeds are subjected in preparing them for use, which at the same time develops the aroma. Cola acummata is a tree with lanceolate or obovate, acuminate, entire, petiolate leaves. The flowers are purplish, unisexual, and in small axillary clusters, frequently arising from the old wood ; the fruit consists of five follicles, each containing 4 to 8 seeds. The seed is made up of two large, fleshy cotyledons. They have much the same constituents as Cacao, but the proportions of these differ (Fig. 337). The leaves oi Waltheria glomerata are used as a hemostatic in Panama like matico, as are also the leaves of Pterospermum acerifolium. The inner bark of Fremontia californica is used for purposes similar to those of elm bark. Mucilage is also found in the following genera : Pentapetes, Wal- theria, Guazmna, Helicteres, and Sterciilia. Tannin is found in the bark of Gtiamima tilmifolia of South America. An oil is manu- factured from the seeds of Sterculia fatida of the East Indies and Cochin China. The seeds of a number of species of Sterculia are edible. Ahrotna angusta of India yields a fiber which has been suggested as a substitute for silk. XIX. ORDER PARIETALES. This is a group of plants of rather wide distribution, and includes perennial herbs like the violets ; evergreen shrubs, such as the Tea Plant ; and vines like the Passion flower. As the name indicates, the plants of this order are characterized by the flowers having, for the most part, ovaries with parietal placentas. a. FAMILY DILLENIACE^.— The plants are mostly trop- ical trees which yield valuable timber. The wood of a species of Dillenia growing in the East Indies also contains red coloring substances. The fruits of Dillenia indica contain citric acid and are used like lemons. The leaves of CurateUa americana contain considerable silicon and are used to polish wood. Dillenia speciosa 6i6 A TEXT-BOOK OF BOTANY. Fig. 338. Leaves, flowers, and fruits of the Tea plant (Thea sinenis, or Camellia viridis). The plant is a shrub or small tree bearing lanceolate, evergreen leaves, and in the axils occur the rather large, white, fragrant flowers. The fruits are small, globular capsules. — Reproduced by permission of The Philadelphia Commercial Museum. of India contains a large percentage of tannin. Some species of Dillenia are cultivated and the foliage and flowers combine to make the plants the most beautiful in the plant kingdom. b. MARCGRAVIACE^.— The members of this family are CLASSIFICATION OF ANGIOSPERMS. 617 partly epiphytic, and have dimorphic leaves, the smaller ones being pitcher-like. The plant which is cultivated in greenhouses, Marc- gravia umbcllata, is used in the Antilles in medicine. c. THEACE^ OR TEA FAMILY.— The plants are shrubs or trees with alternate, evergreen leaves, and perfect, regular Fig. 339. Picking tea on a plantation in Japan, the wall at the left probably being the ruins of an ancient temple. While the plant ordinarily is a shrub, it is kept trimmed and is a bush from 2 to 5 feet high. The plants begin to bear in the third year, and continue to yield a commercial article from 3 to 7 years thereafter. The number of crops per year is determined by the geographical location. In the tropical fields of Ceylon, India, and Japan leaves are picked frequently, while in northern Japan they secure only one crop a year, — Reproduced by permission of The Philadelphia Commercial Museum. flowers with numerous stamens, occurring one or more in the axils of the leaves. The fruit is a 3- to 5-locular, dehiscent capsule. The most important member of this family is Thea sinensis, the two varieties viridis and Bohca furnishing the leaves known as tea. The Tea tree is indigenous to Eastern Asia, and is now extensively cultivated in China, Japan, India, Java, Brazil, Sicily, Portugal and France, and to some extent in the Southern United States (Figs. 338, 339). 6i8 A TEXT-BOOK OF BOTANY. The fresh leaves of Thea do not have the properties which characterize the commercial article, the aroma and other qualities being developed after special treatment. Two general classes of tea are found in commerce, these depending on the mode of treat- ment. Those which are rapidly dried by means of artificial heat constitute Green tea. The leaves which are slowly dried, per- mitting fermentation to set in, furnish Black tea. Tea leaves contain 1.5 to 3.5 per cent, of caffeine; theobromine and the- ophylline (an isomer of theobromine) ; 10 to 20 per cent, of gallo- tannic acid ; quercitrin, and a volatile oil containing, among other components, methyl salicylate. The seeds contain about 30 per cent, of fixed oil, i per cent, of caffeine, and saponin. The leaves furnish one of the sources of the official caffeine. Saponin is found in the seeds of Thea Sasanqua of China and Japan. Two saponin-like substances (assamin and assaminic acid) are found in the seeds of Thea assaniica. The flowers of T. Sasanqua are used in China and Japan to flavor teas. The flowers and leaves of Thea Kissi are used as an insecticide. The red colored sap of Laplacea Hcematoxylon of New Granada is used in medicine. d. GUTTIFER^ OR GAMBOGE FAMILY.— The plants are principally shrubs and trees of the Tropics, that is, if we exclude the Hypericacese which are now put in a group by them- selves. Garcinia Hanburyi is a tree with ovate, petiolate, coriaceous, opposite leaves. The flowers are small, yellow, dioecious, occur- ring in small clusters in the axils of the leaves. The fruit is a pome-like berry, with a papery endocarp and an oily sarcocarp, and 3 or 4 seeds, i in each loculus (Fig. 340). The trees are chiefly valued on account of the gum-resin known as gamboge which they contain. A resin used in making plasters is obtained from Calophyllum brasiliense of Brazil. Balsams resembling Copaiba have been obtained from Calophyllum Calaha of the West Indies. Balsams known as Tacamahac are also derived from the following plants : Bourbon Tacamahac from Calophyllum TaeamaJiaea, India Taca- mahac from C apetalum and Brazilian Tacamahac from Rhcedia Madruno. Balsams are also obtained from Caraipa grandiHora CLASSIFICATION OF ANGIOSPERIMS. 619 of Brazil, and RJiccdia acuminata of Pern. Resins and balsams are obtained from a nnmber of species of Cliisia. A yellow coloring principle, mangostin, is obtained from the bark and fruit of Mangosteen (Garcinia Mangostana ) of the East Indies. Yellow coloring principles are found in Ochrocarpos Fig. 340. Gamboge plant {Garcinia Hanburyi). A branch showing the axillary pistillate flowers and pome-like fruits. — After Baillon. longifolius of India and Vismia acuminata of South America. Tannin occurs in Mahurea palustris of Brazil, Mesiia ferrca of the East Indies, that flower-buds of Ochrocarpos longifolius of India, and several species of Cratoxylum of China and Java. A butter-like fat is obtained from the seeds of Garcinia indica. A fixed oil known as Laurel-nut oil is derived from the seeds of Calophyllum Inophyllum and other species of Calophyllum 620 A TEXT-BOOK OF BOTANY. growing in the East Indies, Cochin China and Brazil, as well as the seeds of Symphonia fasciculata of Brazil. The bark of Clusia pseud o china is used in Peru as a substi- tute for cinchona. An alkaloid is found in Vismia robusta of Java. A gum is obtained from Calophyllum tomentosuin of India and Vismia acuininata, that of the latter being purgative. The flower buds of the India Suringi (Ochrocarpos longifolius) have an aromatic odor resembling cloves. Aromatic principles are also found in other plants of this family. Edible fruits are yielded by the following plants : Mango FRUIT from Garcinia Mangostana and other species of Garcinia ; Mammei apple or Apricot of St. Domingo from Mammea aiiier- icana of tropical America, the latter being used in the prepara- tion of Mammey wine or '* Toddy " and a liquor known as " Eau de Creole." The seeds of Platonia insignis are used like almonds in Brazil and Paraguay; the fruit of the latter plant is quite acid and is eaten with sugar. e. HYPERICACE^ OR ST. JOHN'S-WORT FAMILY.— The plants are herbs or shrubs of the temperate regions, and are represented in the United States by the Hypericums, which are quite common. The flowers are characterized by the numerous stamens which are united into distinct groups or clusters. The flowers of Hypericum perforatum or Common St. John's-wort contain yellow and red coloring principles. Yellow coloring prin- ciples have also been isolated from Hypericum laricifolium of Ecuador and H. elodes of Northern Europe. The entire plant of H. perforatum is used in medicine and contains considerable resin, and a small amount of volatile oil. /. FAMILY DIPTEROCARPACE^.— The plants of this family are principally trees and indigenous to tropical Asia. The family derives its name from the winged fruits of the principal genus Dipterocarpus. A number of economic products are fur- nished by this group of plants. Borneo camphor is obtained from Dryobalanops aromatica. The camphor separates in canals in the older parts of the wood and between the wood and bark, and is obtained by felling the trees, splitting the wood, and then removing the camphor by hand. Owing to the fact that some of the trees do not contain camphor, it is sometimes necessary to fell CLASSIFICATION OF ANGIOSPERMS. 621 a hundred trees in order to obtain 6 or 8 K. of the product. The young twigs of this plant as well as the older wood yield a volatile oil known as Oil of Borneo camphor. GuRjUN BALSAM or Wood oil is obtained from a number of species of Dipterocarpus growing in the East Indies by incising the stems as in the collection of turpentine. The balsam is used as a substitute for copaiba and contains an ethereal oil which consists chiefly of a sesquiterpene, an indififerent resin, and gur- junic acid. Sindor balsam is obtained from Dipterocarpus mar- ■ginatus of Borneo. A resin known as " Piney resin," which is used as a substitute for Dammar, is obtained from a number of species of Valeria growing in India. Chaia resin is obtained from Shorea ruhifolia of Cochin China. The bark of Shorea robusta of Northern India contains 32 per cent, of tannin. The seeds of species of Shorea, Pinanga, Gysbertsiaua and I so pt era yield the fatty oil known in Java as Tangkawang. The seeds of a number of plants of this family contain considerable starch, as Vateria, Vatica and Doona. The woods of the following genera are extensively used : Vatica, Shorea, and Hopea. g. FAMILY TAMARICACE^.— The plants are halophytic shrubs found in the desert regions of Central Asia and Mediter- ranean countries and one genus (Fouquieria) is found in Mexico. Fouqiiieria splendens is cultivated to some extent, and is known as Ocotilla or Coach-whip Cactus. The bark contains gum, resin and wax; the latter is known as Ocotilla wax and resembles beeswax. The twigs of Myricaria germanica of Europe are used as a substitute for hops. A manna-like sugar is formed on the stems of Tamarix mannifera growing in Egypt, Arabia and Afghanistan, as the result of the sting of an insect {Coccus nianni- parus). Tannin is found in a number of species of Tamarix as well as in the galls formed on the plants, the tannin being used for dyeing. A table salt is prepared from the ash of several species of Reaumiiria found in Northern Africa and the East Mediterranean region. h. FAMILY BIXACE^.— These are shrubs or trees found in the Tropics, and are of interest chiefly on account of the seeds of Bixa Orellana which furnish the coloring matter known as Annatto (Orlean, Arnotta). The plant is found in tropical 622 A TEXT-BOOK OF BOTANY. America and also in Polynesia and Madagascar. The seeds are covered with a fleshy arillus from which the coloring matter is prepared by means of water. The insoluble matter is collected, made into cakes and chiefly used for dyeing and coloring. Annatto contains a red crystalline principle, bixin, a yellow coloring prin- ciple, orellin, and an ethereal oil. The root of this plant also con- tains some coloring matter. A yellow coloring principle is found in Cochlospernnim tinctorium of Senegambia and an aromatic resin is obtained from Cochlospcrmum Gossypiuni of Ceylon and Malabar. 1. FAMILY CANELLACE/E OR WINTERANACE.E. — These are trees with aromatic barks having an odor of cinnamon ; pellucid-punctate leaves ; and golden-yellow flowers. The most important member of this family is JVintcrania Canclla growing in the Antilles and in Southern Florida, which furnishes the Canella BARK or False Winter's bark used in medicine. The bark occurs in large quills or broken pieces, from 3 to 10 mm. thick, with the periderm nearly entirely removed, the outer surface yellowish or orange-red with transversely elongated patches of cork and shal- low, whitish depressions ; the fracture is short with numerous resin canals ; the odor aromatic ; taste aromatic, bitter and pungent. It contains mannitol, resin and 0.5 to 1.28' per cent, of a volatile oil containing eugenol, cineol, caryophyllene and pinene. The bark of one or more species of Cinnamodendron of tropical America is sometimes substituted for Canella bark, but it is distinguished by containing tannin, which constituent is not found in Canella. y. VIOLACE^ OR VIOLET FAMILY.— The plants are herbs or shrubs with basal or alternate leaves, perfect, irregular flowers, and 3-valved dehiscent capsules (Fig. 280, /). The best known representatives of this group are the cultivated species of the genus Viola, including the English or sweet violet ( Viola odor- ata), which produces a volatile oil containing ionon ; and the varie- ties of Viola tricolor vulgaris which furnish the pansies of the garden. The entire herb of Viola tricolor has been used in medi- cine and contains the yellow coloring principle viola-quercitrin, salicylic acid and methyl salicylate (Figs. 201, 232). k. FAMILY FLACOURTIACE/E. — These are tropical shrubs and trees, and are chiefly of interest because of their valu- able woods and acid, juicy fruits. A number of them are of CLASSIFICATION OF ANGIOSPERMS. 623 medicinal interest. Chaulmugra oil is said to be obtained from the seeds of Gynocardia odorata of Farther India. The seeds also' contain gynocardic acid and hydrocyanic acid. The latter is also present in the seeds of Hydnocarpus venenata of Southern India and Ceylon and the leaves of Kiggelaria afrieana. A number of species of Lcctia growing in Cuba yield a resin resembling sandarac. The Coccos oil which is used in perfumery is obtained from several species of Myroxylon growing in Poly- nesia. The fixed oils from the seeds of Gynocardia odorata and of several species of Panghim are used in cooking. A bitter principle occurs in the bark of Casearia adstringens of Brazil. A purgative principle is found in C. esculcnta of tropical Asia and Australia. The root of Homalinm racemosum of Guiana contains an astrin- gent principle. /. FAiAlILY TURNERACE^.— These plants are herbs, shrubs and trees mostly found in tropical America, and are of interest on account of the leaves of Turnera diffusa, particularly the variety aphrodisiaca, which yield the Dam i ana of medicine esteemed as a tonic laxative like Rhamnus Purshianus. The drug usually consists of leaves, although the reddish stems, yellowish flowers and globular capsules may be present. The leaves are about 25 mm. long, varying from oblanceolate to obovate ; the margin is serrate-dentate; the color, light-green (older leaves somewhat coriaceous and pubescent); the odor aromatic; taste aromatic and bitter. Damiana contains a volatile oil, resin, and the bitter principle damianin. Ethereal oils are found in other species of Turnera, and T. angiistifolia of Mexico contains con- siderable mucilage. m. PASSIFLORACE^ OR PASSION-FLOWER FAM- ILY.— The plants are mostly herbaceous or woody vines climbing by means of tendrils, vv^ith alternate, palmately-lobed, petiolate leaves and soluary, perfect, regular flowers. The flowers are peculiar in that between the corolla and stamens there are numer- ous, frequently petaloid, colored, sterile, filamentous bodies which are known collectively as the " corona." The fruit is a berry or dehiscent capsule. The genus Passiflora is known as the Passion- flower because the flowers are considered to be emblematic of the Crucifixion, the corona representing the crown of thorns, the 624 A TEXT-BOOK OF BOTANY. stamens the nails, and the gynseclum with its three styles, the three thieves. The rhizomes of the Passion-flowers of the South- ern States {Passiflora incarnata and P. lutea) have been used in medicine. Not much is known with regard to the active principles of these two plants or of the thirty other species of Passiflora which are used in medicine. The fruits of several species of Passi- flora are edible, and a number of them are cultivated on account of their beautiful as well as odorous flowers. n. CARICACE^ OR PAPAW FAMILY.— This family is composed of two genera of latex-containing trees growing in trop- ical America, the best known of which is the genus Carica. The Papaw or Melon tree {Carica Papaya) is a small tree with a straight, slender, usually unbranched trunk which bears at the summit a cluster of long-petiolate, deeply-lobed leaves. The flowers are dioecious, and the fruit is a large, melon-like berry. The green fruits as well as the leaves contain a milk-juice which is obtained by incising them. The material is dried and is used in medicine on account of its containing a proteolytic ferment, papain or papayotin, which is active in the presence of both acids and alkalies. The leaves and fruit also contain the alkaloid car- paine, and in addition the leaves contain the glucoside carposid. The root contains a glucoside somewhat resembling potassium myronate and a ferment which has a decomposing action upon it. A proteolytic ferment is also present in the leaves of Carica quer- cifolia of Argentina. The melon tree is cultivated on account of the fruits, which are edible. o. BEGONIACEvE. — This is a family of tropical plants which are extensively cultivated. They are herbs or shrubs frequently with tuberous rhizomes and with characteristic, asymmetric, varie- gated leaves. They are easily propagated by cuttings, providing they have sufficient moisture, even the leaves giving rise to new plants. The roots of Begonia anemonoides of South America and B. gracilis of Alexico contain purgative principles. Calcium oxal- ate and acid oxalates are found in the leaves of probably all of the species of Begonia. The roots of a number of species of this genus are astringent. p. DATISCACE^. — The plants are trees or shrubs found principally in the Tropics. A bitter principle is found in the CLASSIFICATION OF ANGIOSPERMS. 625 Yellow hemp (Datisca cannabina) of Southern Europe and the Orient. The root contains a yellow colorinj]^ principle, datiscin, which is used in the dyeing of silk. The wood of Octomelcs and Tetrameles is used in the making of tea-chests. XXI. ORDER OPUNTIALES. The plants of this order are succulent, with much reduced leaves, and with flowers characterized by having a perianth with numerous segments and an inferior ovary. a. CACTACE.E OR CACTUS FAMILY.— This is a remark- able family of succulent plants growing largely in the arid regions of Mexico, Brazil and other parts of America. The stems are more or less flattened, terete or tuberculated, in some cases becom- ing branched and woody. The leaves are reduced to scales, but are sometimes larger, more or less cylindrical or dorsiventral, and usually drop off sooner or later. In the axils of the leaves or leaf-scars there are usually groups of hairs and spines. The flowers are mostly solitary, sessile, perfect, regular and conspic- uous. The fruit is usually a fleshy berry, the fruits of a number of species being edible. Quite a number of the Cacti have been used in medicine, the one most commonly employed being the Night-blooming Cerels {Cereus grandiflorus) , which is extensively cultivated on account of its flowers. The flowers and fresh stems are the parts used. They contain several acrid principles, including probably an alka- loid and a glucoside, the drug resembling in its action digitalis. Mescal buttons (Anlialoniuin) are the dried tops of several species of Lophophora growing in Northern ^lexico. The main axis of the plant is under the ground and produces at certain points small aerial shoots which are more or less button-shaped or disk-like, being about 20 to 50 mm. in diameter. In the center of the disk occur tufts of hairs which vary in the different species, and among which are usually found one or more pinkish flowers. The drug has been used like Night-blooming C*ereus, and con- tains several alkaloids, namely, anhalonine (similar to pellotine), mescaline, anhalonidine and lophophorine. Alkaloidal principles are also found in other members of this family. The sap of several species of Cereus of the Antilles has anthel- 40 626 A TEXT-BOOK OF BOTANY. Fig. 341. Prickly Pear or Indian Fig (Opuntia vulgaris), a prostrate, more or less spreading cactus, composed of flattened stems bearing very small, awl-shaped and decidu- ous leaves and short, yellowish-green bristles and occasionally solitary spines. The flowers are pale yellow, opening in the sunshine. The fruit is a succulent berry about 2.5 cm. long. Various of these«cacti are used as food by the cattle, which often eat them with the bristles. Frequently the spines are burnt off by the cattlemen with the use of gasolene torches, so as to prevent the accumulation of spines in the stomachs of the cattle in the form of phyto-bezoars, which are globular accumulations of vegetable tissues. (See p. 577.)— ^ter Troth. CLASSIFICATION OF ANGIOSPERMS. 627 mintic properties, as also that of certain species of RJiipsalis and Opuntia. A caoutchouc-like exudation is obtained from Opuntia vulgaris and otlier species of Opuntia growing in the West Indies. An astringent principle is found in the root and bark of Opuntia Karzvinskiana of Mexico. A tragacanth-like gum is found in Pcireskia Guacainacho of Venezuela, Opuntia rubescens of Brazil and O. Tuna of the West Indies, Mexico and South America. An alcoholic beverage is made by the Indians of Sonora from the fruit- juice of C evens Thunhergii. A number of species of Opuntia yield edible fruits. The Prickly pear is the fruit of Opuntia Tuna growing in the West Indies and tropical America ; Indian fig is derived from Opuntia Ficus-Indica growing in Southern Europe, particularly vSicily ; a fruit also known as Prickly pear or Indian fig is derived from Opuntia vulgaris, a common Cactus growing in sandy soil in the Eastern United States. The Cochineal insect which is official under the name of coccus in a number of pharmacopoeias (Coccus Cacti) feeds upon various of the Cactacecc, more especially the Nopal plant, Nopalea {Opuntia) coccinellifera, a native of Mex- ico and Peru. (See Kraemer, Amer. Jour. Pharrn., 1913, p. 344-) XXII. ORDER MYRTALES OR MYRTIFLOR.E. The plants are herbs or shrubs with complete flowers, rarely apetalous, producing one or more ovules in each loculus. a. THYMEL^ACE^ OR MEZEREUM FAMILY.— The characters of this family are illustrated by the Spurge laurel or Mezereon {Daphne Me^crcum), which is a small shrub about i ^I. high, with oblong-lanceolate, acute, entire, sessile leaves, and small groups of fragrant flowers, the perianth tube of which is purplish- red or white. The fruit is an ovoid, reddish drupe. The bark of Daphne Mezereum and other species of Daphne is used in medicine. The bark of Funifera utilis of Brazil contains a vesicating principle. A principle with similar properties is found in the bark of Leather wood {Dirca palustris) of the Eastern United States and Canada. The fruit and leaves of Gnidia carinata of Cape Colony contain emetic and drastic principles. A poisonous principle is found in Pimelea trichostachya of Australia. A 628 A TEXT-BOOK OF BOTANY. yellow coloring principle is found in several species of Daphne and Thynielcca. The wood of Aquilaria Agallocha of India and China is aromatic and resembles the '' Aloe wood." A balsam is obtained from the wood of Pimclea oleosa of Cochin China. The bast fibers of quite a number of plants are used in the making of paper, as of Daphne in India, Gnidia of Madagascar, Lagctta (L. lintcaria or Lace-tree) of Jamaica and St. Domingo, Thynielcca of the Mediterranean countries and Linodendron of Cuba. The fibers of Leather wood {Dirca palustris) of the Eastern United States and Canada are said to be used in a similar manner. b. FAMILY EL^AGNACE^.— This is a small family represented in the United States by several genera, among which is the Bufifalo berry (Lepargyrcra argentea), a thorny shrub found in the western part of the United States and the Northwest Terri- tory. The fruit is a reddish drupe-like berry which contains a small amount of citric and malic acids, 5 per cent, of sugar, and in composition is much like the currant. It is eaten by the Indians, and used to a great extent in the Western States in the making of jellies. The leaves and flowers of a number of species of Elaeagnus are used in medicine. c. LYTHRACE^ OR LOOSESTRIFE FAMILY.— The members of this family are herbs, shrubs and trees usually with opposite, entire leaves. The flowers are in racemes and the fruit is a capsule. Quite a number of the plants yield valuable woods and a number are cultivated as ornamental plants. The flowers of IVoodfordia florihunda of India contain a red coloring principle, and the bark and leaves of Lafocnsia Pacari of Brazil contain a yellow coloring principle. Considerable tannin is found in the root of the Purple loosestrife {Ly thrum Salicaria) of the Northern United States and Canada, and widely distrib- uted in the Old World ; and also in the fruit of IVoodfordia flori- hunda, a plant which is extensively cultivated in greenhouses. A bitter principle, nessin, is- found in the leaves of Nescca syphilitica of Mexico and probably other species of this genus. Cuphea viscosissima of Mexico is said to resemble digitalis in its physiologi- cal action. A vesicating principle, resembling cantharidin in its action, is obtained from the fresh leaves of Ammannia hacc'ifera of India. A narcotic principle is found in the seeds of Lager- • CLASSIFICATION OF ANGIOSPERMS. 629 strcrmia Flos-rcginco of India. The flowers of Lawsonia inermis, native to and cultivated in the Orient, have an odor resembhng that of the Tea rose. The shrub is also cultivated to some extent in the West Indies and is known in the Orient as the Henna plant. The leaves are used in the preparation of the cosmetic Hinna. They contain an orange or brownish-yellow dye which is used in the dyeing of the skin and hair. d. PUNICACE^ OR POMEGRANATE FAMILY includes a single genus of two species. The Pomegranate (Punica Grana- tiim) indigenous to the Levant and now extensively cultivated is of chief interest. The plants are small trees, the young twigs of which are 4-angled and frequently thorn-like. The leaves are opposite, ovate-lanceolate, entire and short-petiolate. The torus, calyx and corolla are scarlet, and the gynaecium consists of two whorls of carpels. The fruit is an inferior edible berry with a hard pericarp or rind. The pulpy portion is formed from the outer layer of the seed-coat. The bark of the- root and stem is used in medicine (see Granatum, Vol. II). The rind of the fruit is used as an astringent because of the tannin which it contains. It does not appear, however, to contain the alkaloids found in the official bark. e. FAMILY LECYTHIDACE.E.— The plants are mostly shrubs and trees indigenous to the Tropics. They are of chief interest on account of the Brazil-nut (Fig. 342) obtained from Bertholletia excelsa, and the Sapucaya-nut obtained from the Monkey-pot tree (one or more species of Lecythis), both genera of South America. The seeds (so-called nuts) are rich in oil and proteins and are edible. The fruit of Careya arhorea is drupa- ceous and is also edible, the seeds being considered, however, to be poisonous. Bitter narcotic or poisonous principles are also found in the fruit of Planchonia valida of the Molucca Islands and the seeds of a number of species of Lecythis. The fruits and roots of a number of species of Barringtonia are used in China and Java to stupefy fish. The pericarp of the fruit of Fcctida moschata of Guiana contains considerable quantities of an ethereal oil. The flowers of Grias cauMora of the Antilles are used like tea. A cooling drink is made from the sarcocarp of Couroupita guianensis of the West Indies and Guiana 630 A TEXT-BOOK OF BOTANY. /. RHIZOPHORACE^ OR MANGROVE FAMILY.— These are tropical shrubs or small trees with evergreen, cori- aceous leaves, small cymose and axillary flowers, and seeds which germinate while the fruit is still attached to the plant. The best Fig. 342. Brazil-nut (also known as Para nut. cream nut, and nigger-toe), the seeds of BerthoUetia excelsa, a Brazilian tree belonging to the Fam. Myrtaceae. In the illustration is shown a portion of the fruiting branch with some of the long, leathery leaves. The fruits terminating the branches are woody, vary from 10 to 15 cm. in diameter, and are in the nature of a pyxis, — i.e., opening by means of a lid. It encloses about 20 brownish-gray, 3-sided seeds, which are largely exported from Para. — Reproduced by permission of The Philadelphia Commercial Museum. known genus of this family is Rhizophora (Mangrove tree), of which there are three species, the American Mangrove being R. Mangle. This tree produces aerial roots on the stems and branches, and leaves w^hich are characterized by a number of layers of CLASSIFICATION OF ANGIOSPERMS. 631 water-containing cells. The plants grow in muddy swamps, or along the sea-coast where the water is brackish, a number togetiier forming the so-called " Mangrove swamps " (l-ig. 165). The root and bark of the Mangrove, as well as other species of Rhizophora and several species of Bruguiera, contain a large quantity of tannin which resembles catechu. The aerial roots of Rhizophora are used by the natives of Polynesia in the making of bows, and the woods of several genera are used in carpentry. g. MYRTACE^ OR MYRTLE FAiMILY.— This is a group chiefly of shrubs and trees, some, as of species of Eucalyptus, being the loftiest trees known, attaining a height in some instances of 105 M. The plants are indigenous to Australia and tropical America and some are extensively cultivated. Eucalyptus species.— The leaves frequently vary in shape and in arrangement on the young and older branches of the same plant. On the young branches they may be, as in Eucalyptus Globulus, ovate or broadly elliptical, opposite and sessile, while on older branches they are scythe-shaped, glandular-punctate, glabrous, petiolate and alternate. In the latter case the petioles are twisted and the leaves stand edgewise so that both surfaces are equally exposed to the light and hence of similar structure. The flowers are solitary, or in cymes or umbels, occurring in the axils of the leaves. Petals are wanting and the whitish stamens, which are numerous and inflexed in the bud, are covered by an oper- culum or lid which is considered to be formed by the union of the sepals, and which dehisces on the maturing of the stamens, this being one of the most characteristic features of the genus. The fruit is a 3- to 6-locular truncated capsule or pyxis. This is a very important genus from an economic point of view, among the products being the volatile oil (oil of eucalyptus), and eucalyptol, both of which are official, and the tannin or so-called '* gum," known as Eucalyptus kino. Jambosa Caryophyllus {Eugenia caryophyllata). — This is a small tree indigenous to the Molucca Islands and now extensively cultivated in the Tropics. The leaves are opposite, ovate-lance- olate, acuminate, petiolate, entire and evergreen. The flowers are rose-colored and in cymes ; the fruit is berry-like and constitutes the Anthophylli or Mother-clove. The unexpanded flower-buds 632 A TEXT-BOOK OF BOTANY. constitute the drug or spice known as Cloves. (See \^ol. II.) Pimenta officinalis is a tree with opposite, lanceolate, acute, petiolate, pellucid-punctate and evergreen leaves. The flowers are small, white and in axillary racemes. The fruit, known as " All- spice," is used for flavoring. Not only are ethereal oils obtained from the genera Euca- lyptus, Jambosa and Pimenta already described, but also from other members of the Myrtacese. Oil of Bay or oil of Myrcia is distilled from the leaves of Pimenta acris of the West Indies. The oil consists largely of eugenol, methyl-eugenol, chavicol, methyl-chavicol, citral, phellandrene and myrcene, and is used in the preparation of Bay rum. The fruits of P. acris yield 3.3 per cent, of an oil resembling the leaf oil. Cheken leaves are obtained from Eugenia Chekan. They are about 25 mm. long, ovate or rectangular, with entire, somewhat revolute margin, light green, pellucid-punctate, aromatic, astrin- gent and bitter. Cheken leaves yield about i per cent, of a volatile oil containing cineol and pinene; 4 per cent, of tannin; a volatile alkaloid and a glucoside. Oil of Cajeput is obtained from the leaves and twigs of Mela- leuca Leucadendron, particularly the varieties Cajeputi and minor of the East Indies. The principal constituents of this oil are cineol, terpineol, pinene, and a number of aldehydes and acid esters. An oil resembling Cajeput oil is obtained from the leaves and flowers of Myrceugenia camphorata of Chile. The leaves of Myrtus communis, a plant extensively cultivated in the Mediterranean countries of Europe, yield a distillate with water known as Eau d'ange and used as a toilet article. The leaves of the following plants are used as substitutes for tea leaves : Myrtus Molincc of Chile, Melaleuca genistifolia of Australia, and Leptospermum scoparium and other species of this genus growing in New Zealand. The seeds of Eugenia disticha are known in the Antilles as Wild cofifee. Quite a number of the genera of this family yield edible fruits. Guava or Guayava fruit is obtained from Psidium Giiajava of tropical America. Rose apple is the fruit of Jambosa malaccensis, growing in the East Indies and Oceanica. Jambuse berries are derived from Jambosa vulgaris which is extensively cultivated in the Tropics. The CLASSIFICATION OF ANGIOSPERMS. 633 lemon-like fruit of Myrcia coriacea is used in medicine, the bark in tanning-, and the wood in dyeing. The fibrous bark of Eugenia ligiistrina is used like oakum. h. FAMILY COMRRETACE^.— The members of this fam- ily are shrubs or trees, sometimes climbing ; with usually alternate, petiolate, simple leaves ; sessile flowers in racemes ; somewhat fleshy, winged, i-seeded fruits, and are mostly found in the Tropics. Like the Fagacese the plants of this family contain a tannin, similar to gallotannic acid, in nearly all parts of the plant. The Myrobalans of the East Indies are the young fruits of Tenninalia Chebula. The pericarp contains from 5 to 45 per cent, of tannin, the latter amount being found in the fruits known as Long or Chebula Myrobalans. The fruits also contain ellagic and chebu- linic acids. The fruits of Tenninalia Bellerica constitute the Bel- eric Myrobalans. The galls of Tenninalia macroptcra of Africa and other species of Terminalia as well as of Bucida Buceras of tropical America are particularly rich in tannin. A yellow coloring principle is found in Tenninalia Brownii of Africa and is used in dyeing leather. The bark of T. Catappa of Asia and Africa is used to dye leather black. A gum-resin with cathartic properties is obtained from Termi- nalia fagifolia of Brazil. An aromatic resin is found in Ter- minalia august if olia of the East Indies. The fruits of one or more of the Combretace?e are said to be used in the preparation of the arrow-poison of the Negritos. The seeds of Terminalia Catappa and Combretum bntyrosum contain about 50 per cent, of fixed oil. These seeds as well as those of other species of Terminalia and Quisqualis indica of Farther India and tropical Africa are edible. The seeds of the latter plant when unripe are said to be used like mustard. The woods of a number of the plants of the Combretaceae are valuable for building purposes, and some of the genera furnish ornamental plants which are cultivated in greenhouses. i. FAMILY MELASTOMATACE^.— This is a large family of herbs, shrubs, and trees with opposite, 3- to 9-nerved leaves and regular, perfect, often showy flowers. They are chiefly found in South America and are represented in temperate regions by 634 A TEXT-BOOK OF BOTANY the Meadow beauty (Rhexia). Quite a number of the plants are cultivated and a large number yield edible fruits. The fruits, barks and leaves frequently contain coloring principles. A yel- low coloring principle is found in the leaves of a number of species of Memecylon of the East Indies and Africa, which resembles that of saffron and curcuma. Red coloring principles are found in the berries of a number of species of Blakea of South America. A black coloring principle is obtained from the fruit of several species of Tamonea of tropical America, Melastoma malabathri- cum of the East Indies and Tococa guianensis '^^ Xorthern South America and Tiboiichina Maximiliaua of Braz«. Tannin is found in considerable quantity in the barkr of Tibouchina, Dissotis and Rhynchanthera. The leaves of Tamonea theoczans are used in Peru as a sub- stitute for tea. A mucilage is found in the bark of Medinilla crispata of the Molucca Islands. The flowers of the latter plant as well as of M. macrocarpa are used as a remedy for the bite of poisonous serpents. y. ONAGRACEyE OR EVENING PRIMROSE FAMILY. — These are mostly annual or perennial herbs with usually entire or toothed, simple leaves. The flowers are perfect, regular or irregular, epigynous, variously colored, solitary in the axils of the leaves or in somewhat leafy spikes. The fruit is a dehiscent capsule, berry, drupe, or nut. This family is represented in tem- perate regions by such plants as the Willow herb (Epilobium), Evening primrose (CEnothera), on which de Vries has carried on his famous mutation experiments, and Enchanter's nightshade (Circ3ea). The cultivated Fuchsia also belongs to this family. A yellow coloring principle is obtained from the herb and unripe fruits of Jiissiena pilosa of Brazil. The roots of Glnothera bien- nus, O. muricata and other species of this genus are edible. This family also includes the group of aquatic plants, repre- sented by a single genus and one of which, Trapa natans or Water chestnut, is naturalized to some extent in the ponds of Massachu- setts and New York. The fruit is coriaceous, 2- to 4-spinose, and I -seeded. The cotyledons are unequal, rich in starch, and are edible, sometimes being ground and made into bread by the people of Europe and Northern Asia. ^::^!!^T^O.V OP ANGIOSPERMS. ^35 and4-valved. ThirpTanUs i'n':?/.'?'"' "'i"' ye,W p«:, ":„''^ -= '-"ola.e o.^b teng 636 A TEXT-BOOK OF BOTANY. XXIII. ORDER UMBELLALES OR UM BELLI FLOR.E. The plants of this order are widely distributed in northern temperate regions, although there are some representatives in the Tropics. The flowers are small, 4- or 5-merous and epigynous. a. ARALIACE^ OR GINSENG FAMILY.— The plants are mostly trees or shrubs with alternate, petiolate, simple or 3- to 7-compound leaves. The flowers are either in umbels or panicles. The fruit is a drupe or berry. The best known representatives of this family are the English ivy (Hedera Helix) of Europe, and Ginseng (Pajiax quinquefolium) (Fig. 345) growing in the East- ern and Central United States. This plant is the source of the ginseng root of commerce, considerable quantities of which are exported to China, where it is used like the root of Panax Ginseng, a plant growing wild in Manchuria and Korea. Both plants are also cultivated in the United States, the roots from the wild plants being preferred. The root contains a volatile oil, and considerable starch. Several species of A-ralia are used in medicine (Fig. 344). The leaves of the English ivy contain the glucoside helixiri, and a carbohydrate, inosit. They also contain formic, oxalic, malic, tannic and hederic acids, besides the yellow principle carotin. The fruits of the ivy contain a purplish-red coloring substance and are said to be poisonous. The Chinese rice paper is made from the pith of Tetrapanax papyriferiim, which grows wild in Formosa and is extensively cultivated in China. The pith is cut spirally into thin strips, which are spread out flat and then cut into pieces varying from 15 to 30 cm. long and 10 to 12 cm. broad. This paper differs from other papers in that it is a natural product. The rhizome of Panax repens, growing in Japan, contains 20.8 per cent, of a non-toxic saponin with hemolytic properties. h. UMBELLIFER^ OR CARROT FAMILY.— The plants are herbs, frequently with hollow stems ; alternate, simple or com- pound leaves, the base of the petiole often forming an inflated sheath ; and small white, yellowish, greenish or somewhat purplish flowers occurring in simple or compound umbels. The fruit is a cremocarp, having characters which are of important taxonomic CLASSIFICATION OF ANGIOSPERMS. t>37 value/as the presence or absence of secondary ribs, number and position of the vittoe, etc. Fig. 344. Wild Sarsaparilla (Aralia nudicaulis). The plant produces a long, cylin- drical rhizome at or near the surface of the ground, and sends out at various points a single, long-stalked compound leaf, and a shorter, naked scape bearing 2 to 7 umbels of greenish- white flowers. The rhizome is sold as American Sarsaparilla, but it has none of the con- stituents of the true Sarsaparilla. — After Brown. Coriandrum sativum is an annual herb the fruits of which are official. The compound leaves are bi- or tri-pinnate, the leaflets 638 A TEXT-BOOK OF BOTANY. being narrow linear-lanceolate ; and the flowers are white or rose- colored. Fig. 345. Panax quinqtiefolium (Ginseng): A, upper portion of plant showing pal- mately-compound leaves with long-stalked leaflets and the berry-like drupes; B, fusiform root; C, roots showing characteristic stem scars at the upper portion. — From a photograph by Wyss. (See also Fig. 166, p. 305.) Conium rnaculatum or Poison Hemlock is a tall, erect, branch- ing, biennial plant, with purplish spotted stems, large pinnately CLASSIFICATION OF ANGIOSPERMS. 639 decompound leaves and small, white flowers (Figs. 346, 347). The fruit as well as the leaves is used in medicine. Cariun Carvi (Caraway) is a biennial herb with bi- or tri- pinnate, deeply incised leaves, and white flowers. The fruit is official and the leaves are also used in medicine. Pimpinella Anisiim is a small, hairy, annual herb. The leaves are variable, the lower being somewhat cordate and serrate, the middle distinctly lobed, and the upper ones trifid ; the flowers are white. The fruit is official and is also used for flavoring. Fcenicuhim viilgare is an annual or perennial, glabrous herb with very finely dissected leaves, the divisions being narrow-linear. The flowers are yellow, and the involucre and involucels are wanting. The fruit is official. Ferula foctida is a stout, perennial herb with few, ternately compound leaves and small, polygamous, light yellow flowers. The root is rather large and yields the gum-resin asafetida. Asafetida is also derived from other species of Ferula. Ferula Simihul is a tall perenniaF herb with purplish latex- containing stems. The basal leaves are ternately compound and with amplexicaul base. The leaves decrease in size from the base upward, becoming bract-like near the inflorescence. The flcAvers are polygamous, resembling those of F. fa:tida. The root is official and is probably also obtained from other closely related species of Ferula. A large number of the plants belonging to the Umbelli ferae contain essential oils, resins, gum-resins and related substances. The gum-resin ammoniac is an exudation found on the stem and branches of Dorema Aminoniacum and other species of Dorema as a result of the sting of an insect. The plant is found in Western Asia. The gum-resin occurs in yellowish-brown, globular, or somewhat flattened tears which are brittle, milky-white internally, with a distinct balsamic odor and bitter, acrid, nauseous taste. It contains a small quantity of volatile oil having the odor of Angelica. African ammoniac is obtained from Ferula tingitana growing in Northern Africa and Western Asia. The gum-resin galbanum is obtained by incising the root of Ferula galhaniHua and other species of Ferula growing in the Levant. Galbanum occurs in pale yellowish-brown agglutinated A TEXT-BOOK OF BOTANY. Fig. 34&.— Poison Memiock [Lnmum maculatum), showing the spreading habit of the plant and the prominent large compound umbels of flowers.— After Bornemanii. CLASSIFICATION OF ANGIOSPERMS. 641 Europe. 41 642 A TEXT-BOOK OF BOTANY. Fig. 348. Cicuta maculata (Water Hemlock): A, upper part of stem with leaves and compound umbels; B, base of the stem and the thick tuberous roots; C, cross-section of stem showing part of a mestome-strand and the pith with secretory cells (a), vessels (v), libriform (St), pith (p); D, a flower showing petals with long inflexed summit and the five stamens inserted on the disk that crowns the ovary; E, the fruit; F, fruit in longitudinal section showing the two ovules; G, cross-section of a mericarp showing the six vittae or oil- tubes. — After Holm. tears, forming a more or less hard mass, which is brittle when cold but soft and sticky at 37° C. ; the odor is distinct, balsamic ; the taste bitter and acrid. It contains from 10 to 20 per cent, of a volatile oil composed of d-pinene, cadinene, and other principles. CLASSIFICATION OF ANGIOSPER.MS. 643 A volatile oil, known as Ajowan oil, and containing thymol, is obtained from the fruit of Carum Ajowan of Europe, Asia and Africa. A volatile oil containing apiol is found in the fruit and leaves of the garden parsley {Pctroselinmn sativum). Dill oil is obtained from the garden Dill (Anethum graveolens). The fruit of Sweet cicely {IVashingtonia longistylis) yields a volatile oil known as sweet anise oil, which contains anethol. The oil of water fennel (CEnanthe Phellandrium) contains about 80 per cent, of phellandrene. Cumin oil is obtained from Cmniniiiu Cyminum of Turkestan and Egypt, and contains cymene. The roots of a number of the plants of this family contain volatile oils, as Lovage {Levisticum officinale) of Southern Europe; European angelica or garden angelica (Angelica Arch- angelica) ; American angelica or the purple-stemmed angelica (A. atropurpurea) found in the Northern and Eastern United States and Canada; Wild angelica {A. sylvestris) of Europe. c. CORNACEvE OR DOGWOOD FAMILY.— The plants are shrubs or trees with simple, opposite leaves, and flowers in cymes or heads, which in the case of the Flowering dogwood {Cormts florida) are subtended by four large, petal-like, white, or pinkish bracts. The fruit is a i- or 2-seeded drupe. The bark of Corniis florida, a shrub or small tree growing in the United States, contains a bitter principle, cornin ; and a small quantity of gallic and tannic acids. Aucuba japonica, a plant indigenous to the Himalayas, China and Japan and extensively cultivated on account of its crimson berries, contains a glucoside aucubin. It is found in the different varieties and varies in amount from 0.31 to 1.96 per cent. METACHLAMYDE^ OR SYMPETAL^. This is the highest group of plants and is marked by the follow- ing characters : The corolla is sympetalous ; the flowers are mostly perigynous or epigynous and both the corolla and stamens are borne on the perianth tube. The number of parts is definite, there being 5 sepals, 5 petals, 5 or 10 stamens and 2 or 5 carpels. This sub-class includes but six orders, to which, however, belong a large number of medicinal and economic plants. 644 A TEXT-BOOK OF BOTANY. I. ORDER ERICALES. The plants of this order are distinguished by the fact that the stamens are mostly free from the perianth tube. a. PIROLACEyE. — The plants are small, mostly evergreen perennials, and are represented in the United States by several genera. Chimaphila uinbcllata (Prince's pine or Pipsissewa) is a small trailing or creeping plant producing distinct flower- and leaf- branches. The leaves are used in medicine. The flowers are in small corymbs and the petals are white. or pinkish. In CJiimaphila maciilata the leaves are lanceolate, mottled with white along the veins and the flowers are considerably larger. With the Pirolace?e are sometimes grouped the saprophytic plants of the genus ]\Ionotropa. There are two representatives of this genus which are common in the United States, namely, Indian pipe (Monotropa iiJiiflora) and false beech-drops (M. Hypopitys). The latter contains a glucoside or an ester of methyl salicylate, and a ferment gaultherase (Fig. 349). b. ERICACEAE OR HEATH FAMILY.— This is a large family and the plants are widely distributed, especially in the northern mountainous parts of both the Eastern and Western Con- tinents. They vary from perennial herbs to trees. The flowers are usually regular, the stamens being mostly 2-spurred (Fig. 221, S), and the fruit is either a superior or inferior drupe or berry (Fig. 280, H). ArctostapJiylos Uva-Ursi is a low branching shrub which trails or spreads on the ground. The leaves are used in medicine (Fig. 355). The flowers are small, white or pink, few and in short racemes. The fruit is a red, globular drupe. Trailing arbutus (Epigcca rcpcns) is a trailing, shrubby, hairy plant with broadly elliptical or ovate, coriaceous, evergreen leaves and white or rose-colored, fragrant flowers which are either per- fect, with styles and filaments of varying length, or dioecious. The leaves contain similar constituents to those in Uva-Ursi and Chimaphila (Fig. 353). The leaves of wintergreen (GaultJieria prociunhens) are the • ource of true oil* of wintergreen, which consists almost entirely CLASSIFICATION OF ANGIOSPERMS. 645 Fig. 349. Indian Pipe {Monotropa uniflora) , a saprophytic plant of the Ericaceae growing on decaying roots of various plants and on decomposing vegetable matter. The stems are white or yellowish-red, furnished with scales or bracts in place of leaves, and surmounted usually with a single nodding flower becoming in fruit erect. — After Troth. A TEXT-BOOK OF BOTANY Fig. 350. Purple Azalea or Pinkster Flower {Rhododendron nudiflorum) , showing the upright lower stalk surmounted by several spreading branches, each bearing a number of showy tubular flowers at its extremity. The flowers of this plant often appear before the leaves. CLASSIFICATION OF ANGIOSPERMS. 647 of methyl salicylate. It contains a small quantity of an alcohol and an ester giving the characteristic odor. The same principles Fig. 351. Great Laurel or Rose Bay (Rhododendron maximum), an evergreen shrub found in low woods and along streams, chiefly in the mountains of the eastern United States, often forming impenetrable thickets. It is one of the most beautiful of the flowering shrubs, producing from scaly, cone4ike buds numerous corymbose clusters of flowers varying from pale rose to white. — After Troth. probably also occur in several other species of Gaultheria (Fig. 354). 648 A TEXT-BOOK OF BOTANY. Fig. 352. Mountain Laurel (Kalmia latifolia). This is a handsome evergreen shrub growing on rocky hills and in damp soils in the eastern United States. The foliage is bright green, and the showy flowers occur in terminal corymbs, being either of a whitish or pink color. The leaves of many species of Kalmia are said to be poisonous to animals, which is especially true of the Sheep Laurel, known as Lambkill {Kalmia angustifolia), which is not infrequent on hillsides and pastures. — After Troth. The poisonous principle andromedotoxin is found in a number of species of Rhododendron, Leucothoe, and Pieris. This principle is a powerful emetic and one of the most toxic principles known. CLASSIFICATION OF ANGIOSPERMS. Fig. 353. Trailing Arbutus or Mayflower {Epigcea repens). This is one of the first of the early spring flowering plants. It is a prostrate woody plant, usually more or less covered up with the autumn leaves and with rounded and heart-shaped evergreen leaves. The flowers occur in small axillary clusters, are of a rose-red color, dimorphic as to styles and stamens, and are very fragrant. They are transplanted with difficulty, and require an acid soil, as do many other Ericaceae. — After Troth. 650 A TEXT-BOOK OF BOTANY. Fig. 3S4. Wintergreen, teaberry (Gaultheria procumbens) , a low shrub producing slender stems lying at or beneath the surface of the earth and having ascending flowering branches rising to a height of 7 to 12 cm. The leaves are evergreen, obovate or oval, and very spar- ingly toothed; the flowers are whitish, urn-shaped and axillary. The fruit is capsular, sur- rounded by the fleshy calyx, which forms the reddish aromatic globular berries. — Bureau of Plant Industry, U. S. Department of Agriculture. CLASSIFICATION OF ANGIOSPERMS. 651 ^'G. 355. Bearberrv fA . ' ' ing in the aY • "P^ about the size of a n.V ".JJ^'''^^ ''acem 6;2 TEXT-BOOK OF BOTANY. berry-like drupe. In some with a bloom —After Brown. CLASSIFICATION OF ANGIOSPERMS. 653 It probably occurs in the nectar of the flowers of Kalmia and Rhododendron, beinc^ the cause of the poisonous properties of the honey from this source. The leaves of several species of laurel Fig. 357. Dwarf Blueberry or Early Sweet Blueberry {Vacciniuyn penusylvanicum). A low shrub growing to a height of 2 to 6 dm. The leaves are lanceolate or oblong, of a bright green color and minutely serrate with bristle-pointed teeth; the flowers are few, in short racemes, the corolla being whitish and cylindrical; the berries are bluish, covered with a bloom, and ripen during July and August. — After Brown. (Kalmia) contain considerable quantities of this principle, and are poisonous to cattle. The plants of the genus Gaylusaccia are small shrubs distin- guished by having an inferior, berry-like drupe with ten loculi. To this genus belong the huckleberries, as black huckleberry 654 A TEXT-BOOK OF BOTANY. (G. haccata) ; blue huckleberry {G. frondosa) ; and dwarf huckle- berry (G. dumosa). The latter plant grows in sandy swamps in both the United States and Canada and the fruit ripens in May and June. The fruits of the other two species ripen in July and August (Fig. 356). Fig. 358. Low Blueberry or Blue Huckleberry {Vaccinium vacillans). A small shrub with yellowish-green branchlets having nearly entire, narrow, obovate leaves. The flowers are in racemose clusters, appearing before the leaves are half grown, as shown in the illustration; the corolla is pinkish-white, oblong-cylindrical, and somewhat constricted at the throat. The berries are blue, covered with a bloom, and ripen in August and Sep- tember.— After Brown. The plants belonging to the genus Vaccinium vary from very small shrubs to tree-like shrubs and the fruit is an inferior, 5-locular berry with numerous seeds. The blueberries or bilberries (whortleberries) are the fruits of several species of Vaccinium. CLASSIFICATION OF ANGIOSPERMS. 655 The low-bush blueberry (F. pennsylvanicum) yields the berries which ripen in June and July, while the high-bush blueberry ( V. corymbosum) furnishes the fruits which are found in the market in July and August (Figs. 357, 358). Fig. 359. Small Cranberry (Vaccinium Oxycoccos). A trailing evergreen shrub, which produces slender erect or ascending branches with oblong revulute leaves, rose-colored nodding flowers, and a 4-locular, reddish, acid fruit. The berry of the American Cranberry (F, macrocarpon) is much larger and furnishes the fruit of the market. There are many varieties in cultivation. — After Brown. The bilberry of Europe, Vaccinium Myrtillus, a plant growing in Northern Europe and Asia and the Western United States and Canada, is said to destroy Bacillus typhosus and B. Coli, an infusion of the dried berries being used for this purpose. The leaves of this plant contain ericolin and kinic acid. 656 A TEXT-BOOK OF BOTANY. Cranberry is the fruit of several species of Vaccinium which are sometimes grouped in a separate genus, Oxycoccos. There are two principal species : The large or American Cranberry ( V. macrocarpon) in which the berries are ovoid or oblong and the small or European Cranberry ( V. Oxycoccos) in which the berries are globose. The berries contain from 1.4 to 2.8 per cent, of citric acid; and a bitter glucoside, oxycoccin (Fig. 359). Many attempts have been made to cultivate the blueberry, trailing arbutus, and other plants of the Ericaceae. For some years a number of the agricultural experiment stations in the United States have attempted to grow the blueberry as a fruit, but none of these attempts has resulted in the commercial success of blueberry culture, and the experimental results have been chiefly of a negative character. The reason for this has been due, as pointed out by Coville (Bull. No. 193, Bureau of Plant Industry, U. S. Department of Agriculture), to a misunderstanding of the soil requirements for this plant. Plants will thrive only in soil having the following properties : i. The soil must have a distinctly acid reaction, such as is found in peat bogs or on the surface of the ground in sandy, oak, or pine woods. 2. Aeration of the soil is necessary. The rootlets of the swamp blueberry are remarkable in having no root hairs whatsoever, so that their absorptive surface is only about one-tenth that of other plants having root hairs. The growth of the rootlet of the blueberry is much less tlian that of other plants, being about at the rate of only i mm, per day under favorable conditions. The rootlets of healthy blueberry plants are inhabited further by a mycorrhizal fungus which apparently has the property of assimilating nitrogen. II. ORDER PRIAIULALES. Of the three families belonging to this order, there are two which are to some extent represented in temperate regions. a. PRLMULACE^ OR PRIMROSE FAMILY.— The plants are mostly perennial herbs with perfect regular flowers, and capsu- lar fruits. The family is chiefly of horticultural interest, as it contains the genera Primula and Cyclamen. There are several species of Primula cultivated, and they are among the most popular and beautiful of the florist's flowers (Fig. 360). Several of the CLASSIFICATION OF ANGIOSPERMS. 657" i}' * fci^^^'-' ' J^9 0 ^ i^fe^ f! ,^J t7^^^¥^^ ■ ^ «''^.^^H UB^ \ Fig. 360. Primula {Primula obconica), one of several species of Primula which are cultivated in greenhouses and as house plants. The leaves are circular heart-shaped, long petiolate, and very hairy; the flowers are pinkish or lilac color and occur in umbels. The hairs of this plant are very irritating, and cause a dermatitis similar to that produced by poison ivy. — After Guernsey. Species are found in Northern United States and Canada. Dur- ing recent years it has been reported that the wild primrose (P. farinosa) and also the cultivated species {P. obconica) possess 42 658 A TEXT-BOOK OF BOTANY. hairs which are very irritating and cause a dermatitis similar to that produced by poison ivy. A number of the primulas have been examined chemically. The subterranean parts of Primula officinalis contain two crystal- line glucosides, primeverin and primulaverin, which by the action of the ferment, primeverase, produce an anise-like odor. The odors of the other species of Primula are probably due to distinct glucosides: (a) one producing an anise-like odor, as in P. offici- nalis, P. capitata, and P. denticulata; (b) one producing the odor of methyl salicylate, as in P. longifiora, P. clatior, and P. vulgaris; (c) one producing the odor of coriander, as in P. auricula, P. panouica, and P. Pali)iuri. The flowers of a number of species are light in color and somewhat luminous in the dark. b. PLUMBAGINACE^ OR LEADWORT FAMILY.— Perennial, mostly acaulescent herbs, growing in saline locations. Sea lavender or marsh rosemary (Liinonium Carolinian urn) is found in the salt meadows from Labrador to Texas. The plant is reported to contain tannin and has been used in medicine. III. ORDER EBENALES. This order includes three families which are chiefly indig- enous to the Tropics. The leaves are alternate, and the flowers vary in the different families, the fruit being a berry or drupe. a. SAPOTACE^ OR SAPODILLA FAMILY.— The plants usually have a milky latex, and many of them yield gutta-percha, of which the following may be mentioned: Palaquium Gutta, P. oblongifolium, P. borncensc and P. Treubii, all growing in the East Indies. The latex is obtained by incising the trees and collect- ing the exuding juice in suitable vessels. It soon coagulates and forms grayish or reddish-yellow hard masses, which are plastic at 65° to 70° C. Owing to the fact that the material is plastic when heated and firm and tenacious when cold, it is used for a variety of purposes, as in the manufacture of surgical instruments and as a material for filling teeth. Gutta-percha as it exudes from the tree is supposed to consist of a terpene-like hydrocarbon, which on coagulation is oxidized, forming a number of resinous compounds. The plants of other genera of this family also yield CLASSIFICATION OF ANGIOSPERMS. 659 gutta-percha, as Minmsops Batata, M. Elengi, and about fifteen species of Payena growing in the East Indies. Gum Balata is obtained from Miuiusops Balata, a tree of Guiana. The gum is more resinous and flexible than gutta-percha. It contains /?-amyrin acetate and probably lupeol acetate. A gum resembling gutta-percha is obtained from the Sabodilla tree (Achras Sapota). This gum is known in commerce as Gum CHICLE and is obtained from Yucatan. It is whitish, brittle, and yet somewhat elastic, aromatic, and contains 45 per cent, of a colorless crystallizable resin, soluble in alcohol and ether; and 18 per cent, of caoutchouc. It is used in large quantities in the making of chewing gum. The seeds of Illipe hiityracea yield a fixed oil which is known as VEGETABLE BUTTER. A fixcd oil is also obtained from other species of Illipe as well as various species of Bassia, Argania, and Butyrospermum, that from the latter being known as " shea butter." The family is notable on account of the hard woods, known as Ironwoods, which it furnishes, these being yielded by Mimusops Kauki of Farther India and tropical x\ustralia and Argania Sidc- roxylon of Southwestern Morocco. A number of species also yield highly prized edible fruits, as the Sapotilla yielded by Achras Sapota indigenous to the Antil- les and cultivated in tropical countries, and Star apple yielded by Chrysophyllum Cainito of tropical America. b. EBENACE^ OR EBONY FAMILY.— The plants differ from those of the preceding family in not containing a latex. The flowers are monoecious or dioecious and they usually have from two to eight styles. The chief interest is in the genus Diospyros, which yields the wood know^n as ebony. Black ebony is obtained from various species of Diospyros growing in tropical Africa, and Asia, and the Philippine Islands. White ebony is obtained from several species of Diospyros growing in the Philippines. A red ebony is obtained from D. rubra of Mauritius, a green ebony from D. Chloroxylon of Farther India, and a striped ebony from several species growing in the Philippines. Persimmon fruit is obtained from Diospyros virgiiiiana. a tree growing from Rhode Island south to Texas. The astrin- 66o A TEXT-BOOK OF BOTANY. gency of the unripe fruit is due to the tannin which it contains. When it is ripe, which is not until after the appearance of frost, it is palatable and contains considerable malic acid and sugars. The Japanese persimmon is a cultivated variety of D. Kaki and produces a large orange-colored fruit which is not uncommon in the fruit markets in many parts of the world. At the present time the plant is cultivated in California. The bark of our native persimmon is used in medicine. It contains considerable tannin which resembles gallotannic acid, and a crystalline resinous principle with a peculiar odor and slightly astringent taste. c. STYRACACE.E OR STORAX FAMILY.— The flowers of this family somewhat resemble those of the Ebenaceae, but the filaments of the stamens are united in a single series, and there is a single slender style. Styra.v Benzoin is a medium-sized tree with long, ovate, acu- minate leaves which are very hairy on the under surface. The flowers occur in terminal racemes, and are silvery white on the outer surface and reddish-brown on the inner surface. The bal- samic resin yielded by this plant is official as benzoin. IV. ORDER GENTIANALES OR CONTORT.^. The plants of this order have opposite leaves, the flowers are regular and the gynsecium consists of two separate .carpels. The order includes five families, all of which furnish medicinal plants. a. OLEACE^ OR OLIVE FAMILY.— This family is chiefly of interest because of the olive and manna trees. The olive tree {Olea europcea) is indigenous to the Orient and is now cultivated extensively in Southern Europe, Northern Africa, the islands of the Mediterranean, tropical America, includ- ing the Southern Ignited States, and in California. The leaves are narrow-lanceolate, entire, coriaceous and evergreen. The flowers are small, white, diandrous and in axillary racemes. The fruit is a drupe, the sarcocarp of which is rich in a fixed oil known as olive oil. The oil is obtained by expression, and is official. Depending upon the character of the fruits and the amount of oil which they yield, over forty varieties are ?fecognized. CLASSIFICATION OF ANGIOSPERMS. 66i The fresh green olives contain a glucoside oleiiropein, which disappears on the maturation of tlie fruit. Fraxinus Oniiis is a tree rescmbhuf^ the ash, with 7-foHate leaves, and polygamous flowers occurring in compound racemes. The fruit is a flat samara with the wing at the apex. The sac- charine exudation from this plant is official as manna. The white ash {Fraxinus aincncaua) is a valuable tree on account of the timber which it yields. The bark contains a bitter glucoside, f raxin, the solutions of which are fluorescent ; a bitter substance, fraxetin ; an ethereal oil of a butter-like consistency, and tannin. Some of these principles are also found in other species of Fraxinus growing in the United States and Europe. The bark of the fringe tree {Chionanthus virginica) of the Southern United States contains an intensely bitter glucosidal principle, chionanthin, and possibly also saponin. The leaves of the garden lilac {Syringa vulgaris) contain a crystalline glucoside, syringin, and syringopicrin, both of which are probably also found in other species of Syringa as well as the bark and leaves of privet (Ligustrum vulgare), which latter plant is extensively used for hedges. h. LOGANIACEiE OR LOGANIA FAMILY.— The plants are variable in character, being herbs, shrubs, trees or vines. Yellow jessamine (Gelsemium sempervirens) is a twining woody vine, sometimes trailing on the ground for a considerable distance. The leaves are oblong-lanceolate and evergreen. The flowers are bright yellow and dimorphic. The fruit is a septi- cidally dehiscent capsule. The rhizome and roots are official. Carolina pink (Spigelia marilandica) is a perennial herb with ovate-lanceolate, more or less actite and nearly sessile leaves. The flowers are yellow on the inner and scarlet on the outer surface, and occur in a i-sided spike or scorpioid cyme. The fruit is a loculicidal, few-seeded, 2-valved capsule (Fig. 361). The rhizome and roots are official. Strychnos Nux-vomica is a small tree with broadly elliptical. 3- to 5-nerved, reticulately-veined, somewhat acuminate, cori- aceous leaves. The flowers are wdiitish and in terminal cymes. The fruit is a berry of varying size and contains several seeds, the seeds being official. 662 A TEXT-BOOK OF BOTANY. Curare, which is used by the Indians of South America as an arrow-poison, is supposed to be made from the bark of StrycJi- nos toxifera growing in Guiana, and probably other species of Fig. 361. Carolina pink (Spigelia marilandica) showing the rhizome bearing two branches with opposite leaves and flowers in terminal scorpioid cymes. this genus. The active principle of this poison is the alkaloid curarine, which when administered hypodermically has a powerful action resembling that of digitalis. CT.ASSIFICATION OF AXGIOSPERMS. 663 Fig. 362. Closed Gentian {Gentiana Andrewsii), probably one of the most abundant of the fall-flowering Gentians. It is a perennial, forming stout, leafy stems, terminated by sessile clusters of blue flowers. The corolla is closed, and hence this Gentian is sometimes called "Bottle Gentian." It grows in moist ground throughout most of the eastern United States and Canada. — After a photograph by Troth. c. GENTIANACE^ OR GENTIAN FAMILY.— The plants are mostly herbs with regular, perfect, showy flowers occurring usually in small cymes or racemes (Fig. 362). Yellow gentian {Gentiana lutea) is a large, perennial herb 664 A TEXT-BOOK OF BOTANY. (see Vol. II) with large, 5- to 7-nerved, broadly elliptical leaves. The flowers are yellow and occur in axillary cymes. The fruit is a 2-valved, ovoid capsule. The rhizome and roots are official. Many of the gentians are among the most highly prized of the wild flowers, some of them, as the fringed gentian (Gentiana crinita), being one of the most beautiful. The closed gentian (Fig. 357), so called because the flowers remain closed, is quite abundant in moist grounds throughout most of the United States and Canada. The roots of a number of species of American gentian have medicinal properties resembling that of G, liitea. Menyanthes, the yellowish-white horizontal rhizome of Men- yanthes trifoliata (Fig. 363), contains an amorphous glucoside which is slightly soluble in water, soluble in alcohol, and is precipi- tated with tannin. Upon hydrolysis menyanthin yields a volatile oil possessing an odor reminding one of bitter almonds. Swertia Chirata. — The entire plant is official. Herba Centaurii minoris, the entire plant of Erythrcca Cen- taurium of Europe, contains a glucoside, erytaurin, which forms small colorless prismatic and bitter crystals and is slowly hydro- lyzed by emulsin. Sabbatia EUiottii, occurring in the pine barrens of the Southern States, is known as the " quinine herb." d. APOCYNACE.^ OR DOGBANE FAMILY.— The plants vary from perennial herbs to shrubs and trees, contain an acrid latex, and have flowers with the stigrnas and styles united and the stamens distinct. They are mostly found in the Tropics. Apocynmn camiabimtm is a perennial herb with erect or ascend- ing branches. The leaves are oblong-lanceolate, opposite, nearly sessile or with short petioles (Figs. 226, 251). The flowers are greenish-white, the lobes of the corolla being nearly erect and the tube about as long as the calyx. The fruit is a slender, terete follicle containing numerous seeds tipped at the micropylar end with a tuft of hairs. The root is official. The root of a closely related species, namely, spreading dog- bane {Apocymmi androsccinifolium), is sometimes substituted for the official drug. The plant is distinguished by being more spreading in its habit. The leaves are ovate (Figs. 226, 364), the flowers are pinkish, the lobes being revolute, and the tube several times as long as the calyx. CLASSIFICATION OF ANGIOSPERMS. 665 Fig. 363. Buckbean or Bogbean {Me7iya7ithes trifoliata). a perennial herb with fleshy horizontal rhizome, producing erect sterns, bearing three oval or oblong leaflet ^ W "TTl ''''''' ^^^^°^^- ^^'hite or rose-colored, fringed flowers. The plant iowf in ^'r^£:^r^^-^:. ^-^"'^ ''''- ^-^ Canada.-Bureau o^ptnT/ndJItry" 666 A TEXT-BOOK OF BOTANY. Fig. 364. Spreading Dogbane {Apocynum androscEmifolium), a perennial, branching herb, with ovate-oblong, opposite leaves, and small, pinkish fragrant flowers occurring in terminal cymes. All parts of the plants contain a white acrid latex. — After Brown. Strophanthus Konibe. — The plant is a woody climber with elliptical-acuminate, hairy leaves. The flowers are few, charac- terized by long styles, and occur in axillary racemes. The fruit consists of two long follicles containing numerous awned seeds, class,k,c,™n op .ncosphkms, «, which are official In th^ .7 , ^ 668 A TEXT-BOOK OF BOTANY. The leaves and bark of the cultivated oleander {Neriuni Olean- der) contain the glucoside oleandrin, resembling digitalin in its action ; a fluorescent principle, and probably several other principles. The common periwinkle ( Vinca minor) contains the principle vincin, which is supposed to be a glucoside and which probably occurs in other species of Vinca. e. ASCLEPIADACEyE OR MILKWEED FAMILY.— The plants somewhat resemble those of the Apocynaceae. The flower, however, is distinguished by having distinct styles, a 5-lobed corona connecting the corolla and stamens, which latter are mostly monadelphous, and pollen grains that are coherent, forming char- acteristic pairs of pollinia. Few of the plants are of any economic importance. The latex of the stems and the hairs of the seeds are deserving of attention. Pleurisy root, which was formerly offi- cial, is obtained from Asclepias tiiberosa, a plant growing in the Eastern United States and one of the two members of this genus that have orange-colored flowers (Fig. 365). CoNDURANGO is the bark of Marsdenia Cundtirango, a liane of Ecuador and Colombia. It occurs in quilled pieces, the bark being from 2 to 6 mm. thick. Externally it is brownish-gray and with a more or less scaly cork. The taste is bitter, acrid, and aromatic. The drug contains an amorphous glucoside ; an unsatu- rated alcohol occurring in large prisms; and a volatile oil (0.3 per cent.). V. ORDER POLEMONIALES OR TUBIFLOR^. This is a large order of plants, which are mostly herbaceous. The leaves are either opposite or alternate ; the flowers are regular or irregular, the stamens being usually adnate to the corolla. a. CONVOLVULACE^ OR MORNING-GLORY FAM- ILY.— The plants are mostly herbs or shrubs, frequently twining (to the left). They are found mostly in the Tropics, but quite a number of genera occur in temperate regions (Fig. 366). Exogonium Purga is a perennial twining herb with distinctly veined, cordate leaves ; purple flowers with the stamens exserted, and occurring in cymes. The fruit is a 2-locular capsule. The CLASSIFICATION OF ANGIOSPERMS. 669 plants produce slender rhizomes with tuber-like roots, these being used in medicine. Convolvulus Scanunoiiia is a perennial twining hcrlj, with a large tap root, containing a resinous latex, and is the source of the official scammony root. The leaves are sagittate ; the flowers are large, yellowish-white and funnel-form, as in the morning- FiG. 366. Great bind weed (Convolvulus septum) showing trailing or twining habit, the hastate leaves and funnel-shaped corolla. The plant is very resistant to noxious fumes and is usually found in smelter regions. glory, and occur in the axils of the leaves, either solitary or in clusters. The fruit is a 4-seeded, 4-locular, dehiscent capsule. A number of the plants of the Convolvulaceae are cultivated, probably the most important of which is the sweet potato vine (Ipomcca Batatas), a plant extensively cultivated in tropical and sub-tropical countries on account of the edible tuberous roots. The roots contain from 3 to 10 per cent, of sugar and 9 to 15 per cent, of starch, which occurs in larger proportion in plants grown 670 A TEXT-BOOK OF BOTANY. in sub-tropical countries. The starch is a commercial product and is known as sweet-potato starch or Brazilian arrow-root. The grains are more or less bell-shaped and 2- or 3-compound, about the size of wheat-starch grains, and in other ways resemble those of tapioca. To this family also belongs rather an interesting group of parasitic plants, namely, dodder (Cuscuta). They contain the principle cuscutin, and quite a number have been used in medicine. h. POLEMONIACE^ OR POLEMONIUM FAMILY.— A family mostly of herbs and chiefly of horticultural interest. It contains the genus Phlox, which is indigenous exclusively to North America. A number of the species are cultivated and are included among the most valuable hardy, herbaceous perennials. The flowers are among the most beautiful and persistent of our garden plants. Another interesting genus belonging to this family is Polemonium, a number of species of which have been long under cultivation as border plants. Polemonium reptans is rather com- mon in the woods of the Northern United States (Fig. 367). c. HYDROPHYLLACE^ OR WATERLEAF FAMILY.— The plants are herbs or shrubs which are indigenous to Western North America. \^ery few of the plants of this family are of use medicinally, although quite a number are ornamental plants. Eriodictyon califoDiiciim (E. glutinosiim) or Yerba Santa is a shrub growing in Northern Mexico and California. The leaves are official (Fig. 368). The flowers are funnel-form, white or purple, occurring in cymes. The fruit is a dehiscent capsule and the seeds are small and few. d. BORAGINACE^ OR BORAGE FAMILY.— The plants are mostly herbs with regular blue flowers, occurring in scorpioid inflorescence. The best examples of the group are the forget-me-not (Myosotis), the roots of several species of which have been used in medicine ; and the garden heliotrope (Heliotropiim peruvianum), the fragrance of the flowers being due to a volatile oil. This plant, as well as other species of Heliotropum, contains a poisonous volatile alkaloid. At one time there was considerable interest inALKANET^the root of Alkanna tinctoria of Southern Europe and Asia, on account of the red coloring principle alkannin, which is soluble in alcohol, CLASSIFICATION OF ANGIOSPERMS. 671 Fig. 367. Greek Valerian (Polemonium reptans), a perennial, 2 to 4 dm, in height, having alternate pinnate leaves and light blue flowers in corymbs. — After Brown. ether, fixed and ethereal oils, but insoluble in water. Comfrey or SYMPHYTUM is the root of Symphytum officinale and other species of this genus naturalized from Europe in waste places in the United States. It occurs on the market in small, purplish- (i'J2 A TEXT-BOOK OF BOTANY. Fig. 368. Yerba Santa (Eriodictyon californtcum) , a low, evergreen, aromatic shrub, the leaves and stems being covered with a resinous exudation. The leaves are lanceolate, irregularly serrate or nearly entire, and woolly hairy beneath; the flowers are violet or purple in color, and occur in cymjse panicles. — Bureau of Plant Industry, U. S. Depart- ment of Agriculture. CLASSIFICATION OF ANGIOSPERMS. 673 black, more or less curved pieces, which are quite mucilaginous and astringent to the taste. The drug contains a gluco-alkaloid, consolidin, and an alkaloid, cynoglossine. It also contains a small amount of amylo-dextrin, i.e., starch which is not colored blue with iodine, and tannin. The root and herb of hound's tongue (Cynoglossuiu officinale) are both used in medicine. The drug contains the powerful alkaloid cynoglossine, which resembles cura- rine in its action ; and the gluco-alkaloid, consolidin. e. VERBENACE^ OR VERVAIN FAMILY.— The plants are chiefly herbs or shrubs with usually opposite or verticillate leaves and more or less irregular flowers (Fig. 369). To' this family belongs the group of verbenas, some of which are used in medicine, as blue vervain (Verbena hastata), which resembles eupatorium in its medicinal properties ; nettle-leaved vervain (F. urticifolia), which contains a bitter glucoside. The drug LiPPiA MEXICANA cousists of the leaves of Lippia dulcis mexicana, and contains a volatile oil, the camphor lippiol, tannin, and quercetin. Lippia citriodora, found growing in the central part of South America, contains a volatile oil, of which citral is a constituent. Teak-wood, which is one of the hardest and most valuable of woods, is derived from the teak tree (Tecton-a grandis), a large tree indigenous to Farther India and the East Indies. /. LABIATE OR MINT FAMILY.— The plants are mostly aromatic herbs or shrubs, with square stems, simple, opposite leaves, bilabiate flowers, and a fruit consisting of four nutlets. The calyx is persistent, regular or 2-lipped and mostly nerved. The corolla is mostly 2-lipped, the upper lip being 2-lobed or entire, and the lower mostly 3-lobed. The stamens are adnata to the corolla tube, and are either 4 and didynamous, or 2 per- fect and 2 aborted. The ovary is deeply 4-lobed (Fig. 280, /). The Labiatse are especially distinguished on account of the volatile oils which they yield, and a few contain bitter or glucosidal principles. I. The following plants are used in medicine: Scutellaria lateriflora (skullcap). The plant is a perennial herb producing slender stolons somewhat resembling those of 43 674 A TEXT-BOOK OF BOTANY. x'iG. 369. Blue Vervain {Verbena hastala), a tall, perennial herb, with oblong-lanceolate leaves, and numerous terminal spikes of violet-blue flowers. — After Brown. CLASSIFICATION OF ANGIOSPERMS. ''^r r serrate leaves, in the a:iils of which are formed the M„,T-'l ?™,""^ """""'"^ "'««^-oWo„g. Industry, U. S. Department of AgriculturT bilabiate flowers. -Bureau of Plant peppermint and spearmint. The stems are erect or ascendin. commonly branching and from 22 to 55 cm. high (Fig. 370). 676 A TEXT-BOOK OF BOTANY. Marrubiuni vulgare (white hoarhound) is a perennial woolly herb with ascending branches ; the leaves and flowering tops are used in medicine. Salvia officinalis or garden sage is a perennial, somewhat shrubby, pubescent herb. The leaves are ovate, crenulate. The flowers are bluish, somewhat variegated, the calyx and corolla both being deeply bilabiate. Only the two anterior stamens are fertile (bear anthers) ; the connective is transverse, the upper end bearing a perfect pollen-sac, and the lower a somewhat enlarged rudimentary pollen-sac (Fig. 223, F). Hedeouia pulegioides (American pennyroyal) (Fig. 371). Mentha species. — The plants are nearly glabrous, diffusely branching herbs, which form leafy stolons that are perennial (Fig. 184). The leaves and flowering tops of both Mentha piperita (Fig. 372) and Mentha spicata are official. 2. Volatile oils of the following plants are official : Rosmarinus officinalis is a shrub growing in the Alediterranean countries. The plant has linear, coriaceous leaves, and bluish, bila- biate flbwers, the middle lobe of the lower lip of the corolla being large, concave, and toothed on the margin. The flowering tops yield from i to 1.5 per cent, of oil which is composed of 15 to iS per cent, of borneol ; about 5 per cent, of bornyl acetate ; and pinene, camphene, camphor, and cineol. There are two commer- cial varieties of the oil, the Italian and French, the latter having the finer odor. Lavandula officinalis (garden lavender) is a shrub growing in the Northern Mediterranean countries, as well as in England. The leaves are linear, coriaceous ; the flowers are small, light blue, bilabiate, with a tubular calyx, and occur in opposite cymes (verticillasters). The oil is derived from the fresh flowering tops, the flowers yielding about 0.5 per cent. Two kinds of oil are on the market, namely, French and English. The French oil contains 30 to 45 per cent, of 1-linalyl acetate ; linalool ; geraniol, both of which latter constituents occur free and as esters. The English oil con- tains about 5 to 10 per cent, of linalyl acetate and a slight amount of cineol. Spike \d.\Qr\dtv {Lavandula Spica) is sometimes dis- tilled with true lavender (see p. 679). CLASSIFICATION OF ANGIOSPERMS. ^77 Fig. 371. American Pennyroyal {Hedeoma pulegioides). a ow ^"""f P^" •, ^.'°^!"5 in dry soil; having small, opposite, elliptical leaves; and loose ^^l^^^ers of b>lab,atc flowers Sten forming terminal leafy racemes.-Bureau of Plant Industry. U. b. Department of Agriculture. Thymus vulgaris (garden thyme) is a small shrub having linear or linear-lanceolate leaves, and pale blue flowers with 678 A TEXT-BOOK OF BOTANY. strongly bilabiate, hairy calyx, and occur in axillary cymes. The plant grows in the mountains of Southern France. The herb Fig. 372, Peppermint {Mentlia piperita): B, portion of shoot showing petiolate leaves; C, transverse section of leaf 'showing several forms of glandular hairs on lower surface, loose parenchyma (m) and palisade cells (p); D, lower surface of leaf showing stoma (s) and glandular hair (g). Spearmint (Mentha spicaia): A, portion of shoot showing flowers and nearly sessile leaves; E, flower; F, outspread corolla showing cleft posterior lobe (p) and the four adnate, included stamens; G, H, hairs from calyx; I, sphere crystals (sphaerites) of a carbohydrate found in the corolla and style; J, pollen grains. contains from 0.3 to 0.9 per cent, of volatile oil, which is of a dark reddish-brown color, and contains from 20 to 25 per cent, of thymol ; and cymene, 1-pinene, borneol and linalool. The Spanish CLASSIFICATION OF ANGIOSPERMS. 679 oil of thyme contains from 50 to 70 per cent, of carvacrol, but no thymol. 3. Of other plants of the labiat.e which are of interest, the following may be mentioned : Lavandula Spica yields oil of spike, which has an odor of lavender and rosemary. The oil contains camphor, borneol, cineol, linalool, and camphene. Origanum Majorana (Sweet marjoram) is an annual culti- vated herb that has more or less oval, entire leaves, white flowers, and an aromatic odor and taste. It produces a volatile oil which contains terpinene and d-terpineol. Origanum vulgare (Wild marjoram) grows in fields and waste places in the Eastern United States and Canada. The calyx is equally 5-toothed and the corolla varies from white to pink or purple. It contains a volatile oil having an odor somewhat like that of the oil of O. Majorana. Origanuin hirtiim and 0. Onites yield an origanum oil containing carvacrol and cymene. The oils obtained from Cretian Origanum are the source of commercial carvacrol. Pogostemon Patchouli, a plant cultivated in Southern China and the East and West Indies, furnishes the oil of patchouli used in perfumery. Patchouly camphor and cadinene have been isolated from the oil, but nothing, however, appears to be known of the nature of the odorous principle. Hyssopus officinalis (Garden hyssop) contains about 0.5 per cent, of volatile oil to which the characteristic odor of the plant is due. Satureia Jwrtensis (summer savory) yields a volatile oil containing carvacrol, cymene and terpene. Ociunim Basiliciim (Sweet basil) is an herb growing in Europe, and yields an oil which is used in the preparation of Chartreuse and similar liquors. The oil contains methyl chavicol, linalool, cineol, camphor, pinene, and terpin hydrate. Melissa officinalis (Sweet balm) is a perennial herb indigenous to Europe and Asia and also cultivated. The leaves are ovate, dentate, and the flowers are bilabiate, the calyx being bell-shaped and 13-nerved. The taste is bitter, this being due to a bitter principle. The fresh leaves are quite aromatic and produce from 0.1 to 0.25 per cent, of a volatile oil containing a stearoptene. Several species of Monarda known as horsemint or wild 68o A TEXT-BOOK OF BOTANY. Fig- 373- Cat Mint or Catnip {Nepeta Cataria), a hardy perennial herb with heart- shaped, oblong, deeply crenate, velvety, whitish green leaves, bearing in the axils dense whorls of light purplish flowers. It is a common weed and derives its common name from the fact that cats are fond of it, eating it and, rubbing themselves upon it.— Bureau of Plant Industry, U. S. Department of Agriculture. bergamot are used in medicine. The oil was at one time official. The oil of Monarda punctata, a perennial herb found growing CLASSIFICATION OF ANGIOSPERMS. 68i from New York to Texas, contains tliymol, ibymoquinone, liydro- thymoquinone, carvacrol, cymene, and limoncne. Nepeta Cataria (catnip) is a perennial herb naturalized in the United States from Europe (Fig. 373). It contains a bitter Fig. 374. (b) A mass of Ground Ivy {Nepeta hederacea) growing on an embankment, with (a) Spring Beauty {Claylonia virginica). principle, tannin, and an oxygenated volatile oil. .\ cpcta hede- racea or GROUND IVY is a creeping perennial herb with blue bilabi- ate flowers and reniform leaves (Fig. 374). It contains a bitter principle and volatile oil. Cunila origanoidcs, or American dit- 682 A TEXT-BOOK OF BOTANY. TANY, is a small perennial herb growing from New York to Florida, and characterized by its pungent aromatic properties. Leonurus Cardiaca or motherwort is a perennial herb nat- uralized in the United States and Canada from Europe. The ^^^^^^^^m ^^^m ^^^^^^^^^^H ^F v.- i'a-^--^:-:, .: > ■. _^^S^ ^^^^^^1 Fig. 375. Flowering tops of Datura fastiiosa flava, a variety of a plant growing in the East Indies, the Malay Archipelago, and tropical Africa, containing much the same con- stituents as Datura stramonium. — After Newcomb. leaves are 3-lobed; the calyx is 5-nerved and with 5 prickly teeth ; the corolla varies from white to pink or purple. The plant contains a volatile oil of rather an unpleasant odor; a bitter prin- ciple; two resins and several organic acids, namely, malic, citric and tartaric. CLASSIFICATION OF ANGIOSPERMS, 683 /. SOLANACE.F: OR POTATO FA^IILY.— The family includes herbs, shrubs, trees, and vines, which are most abundant in tropical regions. The leaves are alternate and vary from entire to dissected. The flowers are mostly regular, except in hyos- cyamus. The stamens are adnate to the corolla tube the anthers connivent, and the pollen-sacs apically or longitudmally dehiscent The fruit is a berry or capsule in which the sepals mostly persist 684 A TEXT-BOOK OF BOTANY. and sometimes become enlarged or inflated. The seeds have a large reserve layer, and the embryo is frequently curved. Datura Stramonium (Jimson weed, thorn apple) is a large, annual, branching herb, found in waste places in the United States and parts of Canada, being naturalized from Asia, The leaves and flowering tops are official. The large, spiny capsule is shown in Fig. 236, B. D. fastnosa (Fig. 375) has similar medicinal properties. Atropa Belladonna (Deadly nightshade) is a perennial herb producing a large, fleshy root, which is used in medicine (Fig. 376), as are also the leaves and flowering tops. Scopolia carniolica is a perennial herb with nearly entire or somewhat irregularly toothed leaves. The flowers are campan- ulate and dark purple. The fruit is a globular, transversely dehis- cent capsule (pyxidium). Hyoscyamiis niger or henbane is a biennial herb (Fig. 377), the leaves and flowering tops of which are official. Pichi is the dried leafy twigs of Fabiana imbricata, a shrub with small, scale-like leaves, indigenous to Chile. It contains a volatile oil; o.i per cent, of a bitter alkaloid; a glucoside resem- bling aesculin ; and a bitter resin. Solamim Dulcamara (Bitter sweet) is a perennial, climbing herbaceous plant, indigenous to Europe and Asia and naturalized in the Northern United States. The branches which have begun to develop periderm are collected, and were formerly official as Dulcamara. They are cut into pieces 10 to 20 mm. long which are greenish-brown, hollow, with a sweetish, bitter taste and contain a glucoside, dulcamarin, and the gluco-alkaloid solanine (Fig. 378). Solanum caroUnense (Horse nettle) is a perennial herb having numerous yellow prickles on the branches and leaves. The leaves are oblong or ovate, irregularly lobed (Fig. 379). The flowers are white or light blue and occur in lateral cymes. The fruit is an orange-yellow, glabrous berry. The plant is common in waste places in Canada and the United States east of the Mississippi. The root and berries are used in medicine. The root is simple and quite long, 5 to 10 mm. in diameter, yellowish-brown, the bark readily separating from the wood. It has a narcotic odor CLASSIFICATION OF ANGIOSPERMS. 685 Fig. 377. Flowering branch of Hyoscyamus niger annuus, showing sessile, acutely lobed leaves and two of the funnel-form tiowers. — After Newcomb. and a sweetish, bitter, somewhat acrid taste. Both the root and berries contain the gluco-alkaloid solanine, which varies from 0.15 (in the root) to 0.8 per cent, (in the berries). 686 A TEXT-BOOK OF BOTANY. Fxc. 378. Bittersweet iSolanu^ Dulcamara,, -/-^^^^l/^^Jrio" e^^^^^^^^^ with severll types of leaves, varying from "-t^ ^^-^ ^t^^.^Ji^.^reddish berry and very CLASSIFICATION OF ANGIOSPERMS. 687 Capsicum fastigiatum (Cayenne pepper) is a perennial, smooth, herbaceous, or somewhat shrubby plant, with ovate, acuminate, petiolate, entire leaves ; the flowers are greenish-white, and solitary Fig. 379. Horse netrle (Solanum carolinense) : A, portion of shoot showing flowers and fruits and spines on leaves and stem; B, longitudinal section of spine (s) and portion of stern showing glandular (g) and non-glandular (h) hairs, and cells containing small sphenoidal crystals (ca) ; C, thick-walled, strongly lignified cells of spine; D, portion of fibrovascular bundle showing small sphenoidal crystals (ca) of calcium oxalate in the cells accompanying the sieve; E, stellate, non-glandular hair; F, stoma of stem; G, diagram of cross section of flower showing sepals (s), petals (p), stamens (a), ovary (c) ; H, longitudinal section of flower; I, stamen showing terminal pores; J, cross section of 2-locular berry; K, pollen grains, 30 /u. in diameter. in the axils of the leaves. The fruit is official and is known in commerce as African or Cayenne pepper. This plant and a num- ber of other species of Capsicum are indigenous to tropical 688 A TEXT-BOOK OF BOTANY. America, where they are extensively cultivated, as also in Africa and India. Nicotiana Tabacum (Virginia Tobacco plant) is a tall annual herb indigenous to tropical America and widely cultivated. The stem is simple, giving rise to large, pubescent, ovate, entire, decur- rent leaves, the veins of which are prominent and more or less hairy. The flowers are long, tubular, pink or reddish, and occur in terminal spreading cymes. The various forms of tobacco are made from the leaves, which are hung in barns, whereby they undergo a slow drying or process of curing. Other species of Nicotiana are also cultivated, as N. persica, which yields Persian tobacco ; and N. rustica, the source of Turkey tobacco. Tobacco leaves contain from 0.6 to 9 per cent, of the alkaloid nicotine ; an aromatic principle nicotianin or tobacco camphor, to which the characteristic flavor is due and which is formed during the curing of the leaves. The dried leaves yield from 14 to 15 per cent, of ash, consisting in large part of potassium nitrate. Solanum tuberosum (Potato plant) is indigenous to the Andes region of South America and is extensively cultivated on account of the edible tubers. The tubers (potatoes) contain about 75 per cent, of water, 20 per cent, of starch, and nearly 2 per cent, of proteins in the form of large protein crystalloids. The fruits and young shoots contain the gluco-alkaloid solanine and the alkaloid solanidine. The tubers contain a small amount of solanine, which is increased when they are attacked by certain fungi or exposed to light. (Consult pp. 142, 148, 194, and 198.) Besides the potato plant, several other plants belonging to the Solanaceae yield vegetables, as the Tomato plant {Solanum Lyco- persicum) and the Egg plant (Solanum Melongena). Various cultivated species of Capsicum annuum furnish the common red peppers of the market. g. SCROPHULARIACE.E: OR FIGWORT FAMILY.— The plants are herbs, shrubs or trees with opposite or alternate leaves and perfect, mostly complete and irregular flowers. The corolla and stamens show some resemblance to those of the Labi- atse in that the corolla is frequently more or less 2-lipped and the stamens are didynamous. The fruit is a dehiscent capsule and CLASSIFICATION OF ANGIOSPRRMS. 689 the seeds have a reserve layer and a straight or sHghtly curved embryo. Fig. 380. Culver's-root (Leptandra virRinica) showing the verticillate leaves ami the long spike-like terminal racemer. Leptandra virginica {Veronica virginica), or Culver's root, is a perennial herb with leaves in whorls of 3 to 9, those on the upper part of the stem being opposite. They are lanceolate, serrate, 44 690 A TEXT-BOOK OF BOTANY. and pinnately veined ; the flowers are white or bluish, tubular, and in dense racemes. The rhizome and roots are official (Fig. 380). Fig. 381. Foxglove {Digitalis purpurea): The terminal i-sided raceme with slightly irregular, declined, tubular flowers, and a leaf of the first year's plant with long, winged or laminate petiole. Digitalis purpurea (Foxglove) is a tall, biennial, pubescent herb, producing the first year a large number of basal leaves (^^g- 381), and the second, a long raceme of drooping, tubular, CLASSIFICATION OF ANGIOSPERiMS. 691 slightly irregular, purplish flowers ; the inner surface of the corolla is spotted, the stamens are didynamous, and the upjicr calyx segment is narrower than the others. The leaves are official in all the pharmacopoeias. The Scrophulariace?e are well represented in tlie United States, and a number of the plants have medicinal properties. The com- mon MULLEIN [Vcrbasciim Tliapsus) contains a volatile oil, two resins, and a bitter principle. The flowers of mullein contain the same principles and in addition a yellow coloring principle. Other species of Verbascum are used in medicine in dift'erent parts of the world. BuTTER-AND-EGGS (Liiiaria vulgaris) contains a crystalline principle, linariin, antirrhinic acid, a volatile oil, resin, and tannin. Several species of Scrophularia, as S. nodosa of Europe and ^. marilandica of the Eastern United States, contain a pungent resin and a trace of an alkaloid. Turtle-head {Chclonc glabra) (Fig. 382) contains a bitter principle and gallic acid. The plant of HYSSOP {Gratiola officinalis) of Europe contains gratiolin, a bitter glucoside, and gratiosolin. The leaves of Ciiranga aniara of the East Indies contain a glucoside, curanjiin, which resembles digi- talin in its action. h, BIGNONIACE^ OR TRUMPET-CREEPER FAM- ILY.— The plants are shrubs, trees or woody vines, and are repre- sented in the United States by the catalpa tree {Catalpa bigno- nioides) and the trumpet creeper {Tcconia radicans). The bark, pods, and seeds of Catalpa have been used in medicine and con- tain a bitter principle, catalpin, a glucoside, and several crystalline principles. The trumpet creeper contains narcotic poisonous principles. The leaflets of Caroba {Jacaranda Copaia) and other species of Jacaranda contain the alkaloid carobine, an aromatic resin, carobone, and a principle having the odor of coumarin. i. PEDALIACE^. — The plants are herbs indigenous to the Tropics of the Old World, some of which are now cultivated in the Tropics of both hemispheres. Benne oil (oil of sesame) is obtained from the seeds of Sesamum indicum by expression. It consists chiefly of a glycerite of oleic acid, a glycerite of linoleic acid, and myristin, palmitin, and stearin. It is a bland, non-drying oil and is used like olive oil. 692 A TEXT-BOOK OF BOTANY. Fig. 382. Turtle-head (Chelone glabra), a perennial herb with lanceolate, serrate, opposite leaves and short, terminal spikes of whitish or purplish flowers. The corolla is bilabiate, the mouth slightly open, the upper lip broad and arched, suggesting the head of a turtle or snake, hence the origin of the common name. — Bureau of Plant Industry, U. S. Department of Agriculture. CLASSIFICATION OF ANGIOSPERMS. 693 Fig. 383 Purple Gerardia {Gerardia With H„e„ ..... a„a,ar"Cf rS^fnt l-Z^r^'T^r^.t^-"- -- flowers.— After Btown. 694 A TEXT-BOOK OF BOTANY. y. ACAXTHACE.E OR ACANTHUS FAMILY.— The plants are mostly tropical perennial herbs, or shrubs with opposite Fig. 384. Common Plantain (Plantago tnajor). A very familiar weed found along waysides and in poorly kept lawns. The leaves are clustered, Ij'ing near the ground, broadly elliptical and with prominent parallel veins. The flowers occur in long, dense spikes which give rise to small, capsular fruits, being sometimes employed as a green bird food. — After Brown. leaves; in the mesophyll or epidermal cells and parenchyma of the axis occur cystoliths. Several genera are represented in the United States, one of which, Ruellia {Ruellia ciliosa), is the source CLASSIFICATION OF ANGIOSPERMS. 695 Orobal.cl.Ll or ?oot parasites. ^'^ ''^^"Z^ZlfZ^!.. of a cone-Uke stalk with fl«hy Si suroL-^S^/a :;i^ rJrro,^;SVe«o»U. «owets.-A,ter Troth. 696 A TEXT-BOOK OF BOTANY. of the spurious spigelia which has been on the market for some years past. Ruellia ciliosa is a perennial herb which is distinguished from the other species of the genus RuelHa by the leaves, stems, and calyx being distinctly pubescent. The leaves are ovate-lanceolate, nearly sessile and entire ; the flowers are blue, sessile, solitary, or two or three in a cluster, in the axils of the leaves ; the stamens are 4, and exserted. The fruit is an oblong, terete capsule con- taining from 6 to 20 orbicular seeds. The plant is found from New Jersey and Pennsylvania to [Michigan and as far south as Florida and Louisiana. Long cystoliths are found in some of the epidermal cells of both surfaces of the leaf. Quite a number of the plants of the Acanthaceoe are used in the Tropics in medicine. One of these, Adhatoda J^asica of trop- ical Asia, contains the alkaloid vasicine, and is said to have the property of destroying algse which grow in the rice swamps. k. PLANTAGINACE.F: or plantain family.— The plants are annual or perennial herbs, represented by but few genera, but numerous species. The principal genus is Plantago, which includes 200 species that are widely distributed. Several species of Plantago are used in medicine. The common plantain (Plantago major) contains a glucoside, acubin ; emulsin ; and invertin, and the short rhizome, considerable starch. The seed- coat has an outer mucilaginous layer, and the mucilage of the seeds of Plantago Psyllium, P. arenaria (both of Europe), and P. IspagJiiila (of the East Indies) is used as a sizing material. The seeds of a number of the species of Plantago are used as 'bird food, particularly for canaries. /. OROBANCHACE^ OR BROOM-RAPE FAMILY.— This very interesting family is made up of plants which are parasitic upon the roots of other plants and are consequently rather light in color, as they develop no chlorophyll. Squaw-root or Cancer-root (Conopholis americana) has the flowers arranged in the form of a spike looking like an elongated cone, especially after the flowers have begun to turn brown (Fig. 385). Another little olant, also more or less white or yellow in color, is Beech- drops (Epifagiis), which develops upon the roots of the beech. CLASSIFICATION OF ANGIOSPER.MS. 697 VI. ORDEft- RUBIALES. The plants of this order are distinguished from all of the preceding Sympetalae by having flowers which arc distinctly epigy- nous. The leaves are opposite or verticillate. a. RUBIACE^ OR MADDER FAMILY.— The plants are herbs, shrubs, or trees, and of the representatives found in the United States the following may be mentioned: Bluets (Hous- FiG. 386. Cinchona Ledgeriana: A, flowering branch; B, bud and open flower; C, fruiting branch. — After Schumann. tonia species), Partridge-berry {Mitchella repens), and Bedstraw {Galium species). In Mitchella and Houstonia the flowers are dimorphic. Cinchona species. — The plants are mostly trees, or rarely shrubs, with elliptical or lanceolate, entire, evergreen, petiolate, opposite leaves (Fig. 386). The flowers are tubular, rose-colored or yellowish-white, and occur in terminal racemes. The fruit is a capsule, which dehisces into two valves from below upward, the valves being held above by the persistent calyx. The seeds A TEXT-BOOK OF BOTANY •3 G C ^> cj g cij 03 (U 4> CLASSIFICATION OF ANGIOSPERMS. 699 are numerous and winged. There are from 30 to 40 species of Cinchona found growing in the Andes of South America at an elevation above 8'oo M. in a restricted area about 500 miles in length extending from Venezuela to Bolivia. The plants are Fig. 388. Ipecac plant [Cephaelis (Uragoga) Ipecacuanha]: A, flowering shoot; B, flower in longitudinal section; C, fruit; D, fruit in transverse section; E, seed; F, annulate root. — After gchumann. cultivated in Java, Ceylon, New Zealand, and Australia, as well as in Jamaica (Fig. 387). There are two species which furnish the Cinchona bark of medicine: (i) Cinchona Ledgeriana (C. Calisaya Ledgeriana), which has small, elliptical, coriaceous leaves, the under surface o! which is reddish ; small, yellowish, inodorous flowers, and a 700 A TEXT-BOOK OF BOTANY. short capsule; (2) C. succiruhra, which has large, thin, broadly- elliptical leaves, purplish-red calyx, rose-colored petals, and a very long capsule. While C. Ledgeriana yields barks containing the highest amount of alkaloids, C. succiruhra is most cultivated. Uragoga (Cephaclis) Ipecacuanha. — The plants are perennial herbs 10 to 20 cm. high, with a creeping, woody, hypogeous stem. The roots are official in all of the pharmacopoeias (see Vol. II). The leaves are elliptical, entire, short-petiolate, and with divided stipules (Fig. 386). The flowers are white and form small ter- minal heads. The fruit is a blue berry, with characteristic spiral arrangement of the carpels. Coffea arabica is a small evergreen tree or shrub with lanceo- late, acuminate, entire, slightly coriaceous, dark green, short- petiolate leaves, which are partly united with the short inter- petiolar stipules at the base. The flowers are white, fragrant, and occur in axillary clusters. The fruit is a small, spherical or ellip- soidal drupe with two locules, each containing one seed, or coffee GRAIN. The coffee plant is indigenous to Abyssinia and other parts of Eastern Africa, and is cultivated (Fig. 389) in tropical countries, notably in Java, Sumatra, Ceylon, and Central and South America, particularly Brazil, over 600,000 tons being produced annually in the latter country. The yield of one tree is between I and 12 pounds. There are two methods of freeing the seeds from the parchment-like endocarp : In the one case the fruits are allowed to dry and are then broken ; in the other case, which is known as the wet method, the sarcocarp is removed by means of a machine, and the two seeds with the parchment-like endocarp are allowed to dry in such a manner as to undergo a fermentation, and after drying the endocarp is removed. Coffee seeds contain from I to 2 per cent, of caffeine ; from 3 to 5 per cent, of tannin ; about 15 per cent, of glucose and dextrin ; 10 to 13 per cent, of a fatty oil consisting chiefly of olein and palmitin ; io*to 13 per cent, of proteins ; and yield 4 to 7 per cent, of ash.- The official caffeine is derived in part from coffee seeds. In the ROASTING of coffee there is a change in the physical character of the seeds, as well as a change in some of the constit- uents. The AROMA is supposed to be due to an oil known as coffeol, which is said to be a methyl ether of saligenin. CLASSIFICATION OF ANGIOSPERMS. ■01 Fig. 389. Coffee tree growing in Costa Rica. An evergreen shrub, with eUiptical leaves resembling somewhat those of the laurel. The flowers are white, fragrant, and are formed in clusters among the branches, being followed by the berry-like fruits, which when ripe are about the size of and resemble the cranberry. Each fruit contains two elliptical plano-convex seeds, which on being separated constitute the so-called coffee bean of com- merce.— Reproduced by permission of The Philadelphia Commercial Museum. ■02 A TEXT-BOOK OF BOTANY. YoHiMBi (Yohimbihi) bark is obtained from Cory{nanthe Yo- himhe, a tree growing in the Cameroon region of Africa. The pieces of bark are 25 cm. or more in length, 5 to 8 mm. thick, externally dark brown or grayish-brown, and somewhat bitter. Numerous bast fibers are present, but no sclerotic cells. It yields 4 alkaloids (0.3 to 1.5 per cent.), the principal one being yohim- bine (corymbine or corynine), which forms white prismatic Fig. 390. Picking coffee in Brazil. The coffee shrub is cultivated in plantations, and when the berries are ripe they are collected either by shaking the tree and allowing the berries to fall upon a cloth or they are picked by hand directly from the branches, and removed from the field by oxen teams. More than half of the coSee of the world is grown in Brazil, the remainder being obtained in various parts of tropical America and East India. — Reproduced by permission of The Philadelphia Commercial Museum. needles, soluble in alcohol and almost insoluble in water, and on treatment with nitric acid becomes first deep green and then yellowish, changing to a cherry-red if followed with an alcoholic solution of potassium hydroxide (distinction from cocaine). A number of the Rubiaceae contain valuable coloring prin- ciples, as the madder plant ( Rubia tinctormn) , which is a peren- nial herb occurring wild in Southern Europe and formerly culti- vated in France and Germany on account of the coloring principle CLASSIFICATION OF ANGIOSPERMS. 703 ■ p i f^ ^Hi^K ^£^P^ ^^^^■^ ^^^^^^^^^^^^^^H 1 ^^^^^B^^" ^^^1^-r^, Fig. 391. Buttonbush {Cephalanthus cccidentalis) , a small shrub growing in swamps and along streams throughout the United States. The leaves are opposite or whorled in threes. The flowers are white and densely aggregated in spherical peduncled heads; they secrete large quantities of nectar, and are sought to such a degree by the bees that the bush is often called "Honey balls." — After Troth. in its roots. The root is known commercially as made>er, and con- tains when fresh a yellow coloring principle, which on the drying of the root breaks up into several glucosides, one of which on further decomposition yields alizarin, the principle to which the 704 A TEXT-BOOK OF BOTANY. red color of the dried root is due. At present alizarin is made artificially from anthracene, a coal-tar derivative. Morinda citrifolia, a shrub widely distributed in tropical coun- tries, contains a red coloring principle in the flowers and a yellow coloring principle in the roots, the latter being known as morindin and resembling the color principle in madder. The pulp of the fruit of Cape jasmine {Gardenia jasininoides) contains a yellow coloring principle resembling crocin, found in Crocus. The stem and root barks of Button-bush (Cephalanthus occi- dentalis), common in swampy regions in the United States, are used in medicine (Fig. 391). The barks contain a bitter glucoside, cephalanthin, and a tasteless glucoside which is fluorescent in solu- tion. Mitchella rcpcns contains a saponin-like body in the fruit and a tannin and bitter principle in the leaves. Quite a number of species of Galium (bedstraw) are used in medicine and for other purposes. A principle resembling glycyrrhizin is found in wild licorice {Galium circcczans) , a perennial herb growing in dry woods in the United States, and also in Galium lanceolatum, which is found from \^irginia northward to Ontario. The yellow bed- straw {Galium verum) , naturalized from Europe,- contains a milk- curdling ferment. b. CAPRIFOLIACE.^ OR HONEYSUCKLE FA^IILY.— The plants are perennial herbs, shrubs, trees, or woody climbers with opposite, simple or pinnately compound leaves. The flowers are perfect, epigynous, regular, or bilabiate, and arranged in corymbs. The fruit is a berry, drupe, or capsule. They are mostly indigenous to the northern hemisphere. Viburnum pvunifolium (Black haw) is a shrub or small tree 25 cm. in diameter. The winter buds are acute and reddish- pubescent ; the leaves are ovate, elliptical, obtuse or acute at the apex, somewhat rounded at the base, finely serrulate, glabrous, and short-petiolate (Fig. 392) ; the flowers are white and in nearly sessile cymes ; the fruit is a small, oval, bluish-black, glaucous, inferior drupe. The root-bark is official. Viburnum Opulus (Wild guelder-rose or cranberry-tree) is a shrub about half the height of V. prunifolium, with broadly ovate, deeply 3-lobed and coarsely dentate pubescent leaves. The CLASSIFICATION OF AXGIOSPERMS -»- Fig. 302. Fruiting branch of Viburnum prumjolnan. A row-vvood (i: dentatun.), with broadly ovate coarserden' tate leaves and blue drupes, which becor'e nearly black when 45 7o6 A TEXT-BOOK OF BOTANY. ripe; Soft-leaved arrow-wood (F. molle), which somewhat re- sembles V. dentatum, but has larger leaves that are crenate or dentate and stellate-pubescent on the lower surface ; Larger withe- rod {V. nudum), having nearly entire leaves and a pink drupe, which becomes dark blue. Samhucus canadensis (American elder) is a shrub growing in moist places in the United States as far west as Arizona and in Canada. The leaves are 5- to 7-foliate, the leaflets being ovate, elliptical, acuminate, sharply serrate, and with a short stalk ; the flowers are small, white, and in convex cymes. The fruit is a deep purple or black berry-like drupe. The dried flowers are used in medicine. They are about 5 mm. broad, with a 5-toothed, turbinate calyx, and a 5-lobed, rotate corolla, to which the 5 sta- mens are adnate. The odor is peculiar and the taste is muci- laginous and somewhat aromatic and bitter. The active principles have not been determined, but are prob- ably similar to those of 5". nigra. The inner bark is also used in medicine and contains a volatile oil, a crystallizable resin, and valerianic acid. It does not appear to contain either tannin or starch. The roots of elder contain a volatile principle somewhat resembling coniine. The pith consists chiefly of cellulose, is deli- cate in texture and has a variety of uses (Fig. 132). The Black elder {Samhucus nigra), which is a shrub com- mon in Europe, is characterized by narrower leaflets, a 3-locular ovary, and black berries. The flowers are official in some of the European pharmacopoeias. They contain about 0.4 per cent, of a greenish-yellow, semi-solid volatile oil, which when diluted has the odor of the flowers. They also contain an acrid resin. The Red-berried elder or mountain elder {S. pubens) some- what resembles the common elder, but the stems are woody, and the younger branches have a reddish pith. The flowers are in paniculate cymes, and the fruits are scarlet or red. Other plants of the Capri foliaceae are also used in medicine. Horse gentian {Triosteum perfoliatmn) , a perennial herb with connate-perfoliate leaves and small, orange-red, globular drupes, growing in Canada and the United States as far west as Kansas, furnishes the drug (rhizome) known as Wild ipecac or Trios- teum. The rhizome is yellowish-brown, somewhat branched, CLASSIFICATION OF ANGIOSPERMS. 707 cylindrical, 10 to 20 cm. long, 10 to 15 mm. in diameter, with numerous cup-shaped stem-scars, and coarse, spreading roots ; it is rather hard and tough, and has a bitter, nauseous taste. Triosteum contains an emetic alkaloid, triosteine, and considerable starch. The seeds of Triosteum pcrfoliatitni are sometimes roasted and employed like coffee, the plant being known as Wild coffee. The roots and stems of the following plants are sometimes employed: The Snowberry (SympJioricarpos racemosus), the Bush honeysuckle (Dicrvilla Lonicera), and various species of Lonicera, these being also known as honeysuckles. VII. ORDER VALERIANALES OR AGGREGATE. The plants are mostly herbs with an inferior ovary, which is either unilocular wdth a single pendulous ovule, or tri-locular with frequently but a single anatropous ovule. a. VALERIANACE^ OR VALERIAN FAMILY.— The plants are herbs with opposite, exstipulate leaves, small, perfect, or polygamo-dioecious flowers, occurring in corymbs. The fruit is dry, indehiscent, and achene-like. The calyx is persistent, be- coming elongated and plumose, and resembling the pappus in the Compositae. Valeriana officinalis (Garden or Wild valerian) is a tall, peren- nial herb, more or less pubescent at the nodes. The leaves are mostly basal, pinnately parted into seven or more segments, which are lanceolate, entire, or dentate. The flowers are white or pink and arranged in corymbed cymes. The calyx is much reduced, consisting of 5 to 15 pinnately branched teeth (pappus) ; the corolla is tubular, somewhat sac-like on one side, but not spurred as in other members of this family ; the stamens are 3 in number and adnate to the corolla tube ; the stigma is 3-lobed. The fruit is ovoid, glabrous, and with a conspicuous plumose pappus. The rhizome and roots are official. The young leaves of several species of Valerianella are used as a salad and are cultivated like spinach, as the European corn- salad (F. olitoria), which is also cultivated to some extent in the United States. h. DIPSACACE^ OR TEASEL FAMILY.— The plants are annual or perennial herbs, chiefly indigenous to the Old World. 7o8 A TEXT-BOOK OF BOTANY. The flowers are arranged in heads on a common torus, resem- bling in some cases those of the Compositse. Some of the plants are used in medicine, as the roots, leaves, flowers, and seeds of Fuller's teasel (Dipsacus fullonum), the roots of Siiccisa pratensis of Europe, and several species of Scabi- osa and Cephalaria. The seeds of Cephalaria syriaca when admixed with cereals give a bread that is dark in color and bitter. This family is, however, chiefly of interest on account of Fuller's teasel, which is a cultivated form of Dipsacus ferox, indigenous to Southwestern Asia, the plant being cultivated in Europe and New York State. The elongated, globular heads, with their firm, spiny, and hooked bracts, are used in the fulling of cloth. VIII. ORDER CAMPANULAT^. This order differs from the two preceding by having the anthers united into a tube (syngenesious). It includes three prin- cipal families, which are distinguished by differences in the char- acter of the androecium: (a) Cucurbitacese, in which there are three stamens, having not only the anthers united but the fila- ments also (monadelphous) ; {h) Campanulaceae, in which there are five stamens, both the filaments and anthers being united into a tube; (c) Compositse, in which there are five stamens, but the anthers only are united, the filaments being separate (Fig. 82, A). a. CUCURBITACE^. OR GOURD FAMILY.— The plants are mostly annual, tendril-climbing or trailing herbs (Fig. 66), mainly indigenous to tropical regions. The leaves are alternate, being opposite the tendrils, petiolate, and entire, palmately lobed or dissected. The flowers are epigynous ; the petals are borne on the calyx tube and frequently are united (campanulate) ; the ovary is I- to 3-locular and with few or many anatropous ovules. The fruit is a pepo, which is indehiscent but may burst somewhat irregularly. ■Citrullus Colocynthis is a trailing herb with deeply lobed leaves. The flowers are yellow, axillary, and monoecious, the staminate being with short filaments and glandulaf pistillodes (aborted pistils), and the pistillate having a 3-locular, globose ovary and three short staminodes. The fruit is globular, 5 to 10 CLASSIFICATION OF ANGIOSPERAIS. 709 cm. in diameter, smooth, greenish, and mottled. The fruit de- prived of the epicarp is official. Cucurbita Pepo (pumpkin-vine) is an extensively trailing hispid vine, with large, nearly entire, cordate leaves having long petioles. The tendrils are branching. The flowers are large, deep yellow, and monoecious ; the staminate ones being in groups and the pistillate single. The fruit is a large, yellowish berry sometimes weighing from 10 to 72 K. The seeds are numerous and are official as Pepo. EchaUiiim Elaterium (Squirting cucumber) is a bristly-hairy, trailing perennial herb with thick, rough-hairy, cordate, some- what undulate leaves. The flowers are yellow, monoecious. The fruit is ellipsoidal, about 4 cm. long, rough-hairy or prickly, pend- ulous, and at maturity separates from the stalk, when tlie seeds are discharged upward through a basal pore. The plant is indig- enous to the European countries bordering the Mediterranean, the Caucasus region, Northern Africa and the Azores. The juice of the fruit yields the drug Elaterium, which is official in the Britisii Pharmacopoeia. Elaterium yields 30 per cent, of the ELATERiN of the PharmacoDoeias. From the latter by fractional crystallization from 60 to 80 per cent, of a-elaterin, a l^vo-rota- tory crystalline substance is separated, which is completely devoid of purgative action; and varying amounts of ^-elaterin, a dextro- rotatory crystalline compound which possesses a very high degree of physiological activity (Power and Moore, Ph. Jour., 29, Oct. 23, 1909, p. 501 ; and Proc. Chcm. Soc, No. 362, 1909, 'p. 1985). Bryonia or bryony is the dried root of Bryonia alba (White bryony), a climbing herb indigenous to Southern Sweden, East- ern and Central Europe, including Southern Russia, and Northern Persia (Fig. 181). The root contains two bitter glucosides, bryonin and bryonidin ; two resinous principles and considerable starch. Bryonia dioica (Red bryony) also has medicinal proper- ties and is a source of the drug. B. dioica has red berries, while the fruit of B. alba is black. The latter plant is sometimes known as Black bryony, but this plant should not be confounded with Tamils communis (Fam. Dioscoreaceae), of Southern Europe, the rhizome of which is known commercially as Black bryony. The fruits and seeds of various members of the Cucurbitacese 7IO A TEXT-BOOK OF BOTANY. contain powerful drastic and anthelmintic principles. A number of the plants, however, are cultivated on account of the fruits, which are used as food, as the pumpkin already mentioned, the WATER MELON (Citntllus vulgaris) , indigenous to Southern Africa and cultivated in Egypt and the Orient since very early times ; CANTALOUPE or musk-melon, derived from cultivated varieties of Ciicumis Melo, indigenous to tropical Africa and Asia, also culti- vated since early times. The common cucumber is obtained from Cuciimis sativus, which is probably indigenous to the East Indies. These fruits contain from 90 to 95 per cent, of water, and the water melon contains 3.75 per cent, of dextrose, 5.34 per cent, of saccharose, and yields 0.9 per cent, of ash. Luffa cylindrica is an annual plant indigenous to the Tropics of the Old World. It is cultivated to some extent in America, but especially in the Mediterranean region. The fruit is more or less cylindrical and 20 cm. or more long. The pulp is edible and the fibrovascular tissue forms a tough network, which, when the seeds, epicarp, and pulpy matter are removed, constitutes the LUFFA-SPONGE. The fruits of Luffa opcrculata and L. echinata, both found in Brazil, contain a bitter principle resembling colocynthin. b. CAMPANULACE^ OR BELL-FLOWER FAMILY.— The plants are mostly annual or perennial herbs, but are some- times shrubby, with an acrid juice containing powerful alkaloids. The rhizomes and roots of about twelve of the genera contain inulin. The leaves are alternate ; the corolla is regular, cam- panulate and rotate, or irregular, as in Lobelia. The fruit is a capsule or berry containing numerous small seeds. Lobelia inflata (Indian or Wild tobacco) is an annual, pubes- cent, branching herb (Fig. 224 j, the dried leaves and tops of which are official (see Vol. II). About 15 different species of Lobelia are used in medicine. The most important of those grow- ing in the United States is the Cardinal flower or Red lobelia {Lobelia cardinalis) , a plant found in moist soil from Canada to Texas, and characterized by its long, compound racemes of bright scarlet or red flowers. The Blue cardinal flower or Blue lobelia (L. syphilitica) is a plant of nearly the same habit and same gen- CLASSIFICATION OF ANGIOSPERMS. 711 eral character, except that the flowers are of a bright dark blue color or occasionally white. c. FAMILY COMPOSITE.— This is a large group of plants, which are annual, biennial, or perennial herbs, under-shrubs, shrubs, trees and twiners or even climbers, a few being aquatic. They contain inulin, a constituent peculiar to this group of plants. The most distinguishing character is the inflorescence, which is a head or capitulum (Fig. 228), consisting of one or two kinds of flowers, arranged on a common torus, and subtended by a number of bracts, forming an involucre. The flowers are epigy- nous and the fruit is an achene, usually surmounted by the per- sistent calyx, which consists of hairs, bristles, teeth or scales, which are known collectively as the pappus (Fig. 227). The individual flowers are called florets (Figs. 241, 242), and may be hermaphrodite or pistillate, monoecious, dioecious, or neutral. Depending upon the shape of the corolla, two kinds of flowers are recognized, one in which the corolla forms a tube, which is 5-lobed or 5-cleft, known as tubular flowers (Figs. 22y, 22S, C) ; and one in which the petals are united into a short tube, with an upper part that forms a large, strap-shaped, usually 5-toothed limb, known as ligulate flowers (Figs. 227, 228, D). In some of the plants of the Compositae the head consists of ligulate flowers only, but in the larger number of plants the head is composed of both tubular and ligulate flowers or tubular flowers alone and accordingly two main groups or sub-families are dis- tinguished. The sub- family in which all of the flowers are lig- ulate is known as Liguliflor.e, or Cichorl\ce.e, by those who give the group the rank of a family. This group includes plants like dandelion, chicory, lettuce, and Ilieracium. The group or sub-family in which the flowers are all tubular or ligulate on the margin only is known as the Tubuliflor/E. When the head consists only of tubular flowers it is called discoid, but when ligulate flowers are also present it is called radiate. \Mien the heads are radiate, as in the common daisy, the tubular flowers are spoken of as disk-flowers, and the ligulate flowers as ray- flowers. The disk-flowers are usually perfect, while the ray- flowers are pistillate or neutral (without either stamens or pistils). By some systematists the Tubuliflorse are divided into groups 712 A TEXT-BOOK OF BOTANY. which have been given the rank of famiHes. This division is based especially on the characters of the stamens. In a small group represented by the ragweed and known as the Ambrosi- ACE.^, the anthers, while close together (connivent) , are not united, and the corolla in the marginal or pistillate flowers is reduced to a short tube or ring. In a large group, which includes probably 10,000 species and which is considered to be the CoMPosiT.^i: proper, the stamens in the tubular flowers are syngenesious and the marginal or ray-flowers are distinctly ligulate. This group includes the daisy, sunflower, golden-rod, aster, thistle, and most of the plants which yield official drugs. It may also be added that the Compositae is considered to be the highest and youngest group of plants. Taraxacum officinale (Dandelion) is a perennial, acaulescent herb with milky latex; oblong-spatulate, pinnatifid or runcinate, decurrent leaves, and with a i -headed scape, the stalk of which is hollow. The flowers are ligulate, golden-yellow and numerous ; the involucre consists of two series of bracts, the inner one of which closes over the head while the fruit is maturing, afterward becoming reflexed. The fruit consists of a loose, globular head of achenes, each one of which is oblong-ovate and with a slender beak at the apex which is prolonged into a stalk bearing a radiate tuft of silky hairs, which constitute the pappus. The root is fusi- form and usually bears at the crown a number of branches 2 to 5 cm. long, having a small pith and other characters of a rhizome. The root is official. Lactuca virosa (Poison lettuce) is a biennial prickly herb, with milky latex and oblong-obovate, spinose-toothed, runcinate basal leaves and with alternate, somewhat sessile or auriculate, scattered stem leaves, the apex and margin being spinose. The flowers are pale yellow and occur in heads forming terminal pani- cles. The involucre is cylindrical and consists of several series of bracts. The flowers are all ligulate and the anthers are sagit- tate at the base. The achenes are flattish-oblong, and the pappus, which is raised on a stalk, is soft-capillary, as in Taraxacum. The prepared milk-juice is official as Lactucarium. Eupatorium perfoliatum (Boneset or Common thorough wort).. ^-The leaves and flowers are used in medicine. CLASSIFICATION OF ANGIOSPERMS. 713 Eupatorimn sehandianum, which is added to Mate as a sweet- ening agent, contains two sweet glucosides ; eupatorin and rehan- din ; a bitter principle, and a resin. Grindelia species. — The plants are perennial, greenish-yellow, resinous herbs, sometimes being under-shrubs, witli alternate, sessile or clasping, oblong to lanceolate, spinulose-dentate leaves, and large, terminal, yellowish heads, consisting of both ligulate and tubular flowers. The leaves and flowering tops of Grindelia camporum, G. cimeifolia and G. sqiiarrosa are official. Erigeron canadensis or Leptilon canadense (Canada fleabane) is an annual or biennial, hispid-pubescent herb found growing in fields and waste places in nearly all parts of the world. The stems are simple, with numerous crowded leaves and numerous flowers occurring in terminal panicles. The plants are sometimes branched and i to 3 M. high. The leaves are linear, nearly entire, of a pale green color, the lower and basal ones being spatulate, petiolate and dentate or incised. The flowers are white and the heads are composed of both ligulate and tubular florets, the former being pistillate and not longer than the diameter of the disk. The pappus consists of numerous capillary bristles and the involucre, which is campanulate, consists of five or six series of narrow, erect bracts. The fresh flowering herb contains 0.3 to 0.4 per cent, of a volatile oil which is official, tannin, and a small amount of gallic acid. The oil is obtained by distillation and consists chiefly of d-limonene. The genus Erigeron includes a number of species which have medicinal properties. E. annuus (Sweet scabious or Daisy flea- bane) is a low, branching, annual herb, characterized by its linear- lanceolate or ovate-lanceolate leaves and its conspicuous flowers, which resemble those of the common daisy, the ray-flowers often being tinged with purple (Fig. 393). It contains a volatile oil resembling that of Canada fleabane, and tannin. The Philadel- phia fleabane (Erigeron philadelphiciis) is a perennial herb pro- ducing stolons, and has clasping or cordate leaves, the basal being spatulate, and is further distinguished by its light purplish-red ray-flowers. Anthemis nobilis (Roman chamomile) is an annual or peren- 714 A TEXT-BOOK OF BOTANY. nial, procumbent, branched herb, with numerous 2- to 3-pinnately divided leaves, the ultimate segments being narrow-linear. The flowers occur in terminal heads with long peduncles, a conical torus and few white pistillate ray-flowers. The flowers of culti- FiG. 393. Daisy- fleabane (Erigeron annuus). vated plants are official (see Vol. II), the heads consisting mostly of ligulate flowers, forming so-called " double flowers," as in the cultivated chrysanthemums. Anacyclus Pyrethnun (Pellitory) is a perennial herb resem- bling Anthemis nobilis in its general characters. The ray-flowers, CLASSIFICATION OF AxXGIOSPERMS. 715 however, are white or purplish, and the pappus consists of a rinjr or scale. The root is official. Matricaria ChamomiUa (German chamomile) is an annual, diffusely branched herb, with pinnately divided leaves, consisting of few, linear segments. The flowers are official (Figs. 22S, 394). Fig. 394. A single plant of Matricaria ChamomiUa, showing finely divided leaves and numerous composite flowers. — After Newcomb. Arnica tnontana is a perennial herb with small rhizome ; nearly simple stem ; opposite, somewhat connate, entire, spatulate, hairy leaves, and yellow flowers in large heads with long peduncles. The flowers are official. Arctium Lappa (Burdock) is a coarse, branched, biennial or A TEXT-BOOK OF BOTANY. Fig. 395. Chicory or Succory {Cichorium Intybus), a branching Perenmai ^erb Jit^ oblong or lanceolate, more or less clasping leaves and axillary clusters of violet-blue cowers. The plant is cultivated as a pot herb and salad, and the young roots are used hke carrots. The plant is more widely grown for its roots, which are used in the preparation of a substi- tute of coSee. — After Brown. CLASSIFICATION OF ANGIOSPERMS. 717 perennial herb, with alternate, broadly ovate, repand, entire, tomen- tose, mostly cordate leaves, the basal ones being from 30 to 45 cm. long. The flowers are purplish-red or white, tubular and form rather large corymbose heads ; the involucre consists of numerous lanceolate, rigid, nearly glabrous bracts, which are tipped with Fig. 396. Burdock {Arctium Lappa), a biennial herb with large, mostly cordate leaves crowded at the base of the stems, and bearing small clusters of purplish flowers in the shorter branches above. It is a common roadside weed, and well known because of the burr-like fruits, consisting of the hooked tips of the bracts of the involucre. — After Brown. hooked, spreading bristles. The achenes are oblong and some- what 3-angled, and the pappus consists of numerous short bristles (Fig. 396). The root is used in medicine. The common burdock (Arcthini mmiis) resembles A. Lappa, but is a smaller plant and is more common in the United States. The heads are smaller and the inner bracts are shorter than the 7i8 A TEXT-BOOK OF BOTANY. tubular flowers, the bristles of this series being erect and with the outer spreading. Calendula officinalis (Marigold) is an annual herb with alter- nate, spatulate, oblanceolate, entire or serrate leaves. The flowers are yellow and form solitary heads, consisting of both ray and tubular florets. In the cultivated varieties most of the tubular florets are changed to ligulate, the latter being official (Fig. 227). While the Compositae include a large number of genera and species, the plants do not yield many important drugs, although a number are used in medicine and for other purposes. The so-called Insect Flowers {Pyrethri F lores) are the partly expanded flower-heads of several species of Chrysanthe- mum, and are used in the preparation of a powder which is a powerful insecticide. The plants are perennial herbs resembling in their habits the common white daisy (C. Lcucanthetnum) . The Dalmatian Insect Flowers are obtained from C. cineraricc folium, growing in Dalmatia, and cultivated in Northern Africa, Cali- fornia and New York. The heads as they occur in the market are about 12 mrh. broad, light yellowish-brown and have a slightly rounded or conical torus, which is about 12 mm. in diameter and consists of 2 or 3 series of lanceolate involucral scales. The ray- florets are pistillate, the corolla varying in length from i to 2 cm. and having numerous delicate veins and 3 short, obtuse or rounded teeth. The tubular flowers are perfect and about 6 mm. long. The ovary is 5-ribbed and the pappus forms a short, toothed crown. The odor is distinct and the taste bitter. Persian Insect Flowers are derived from C. roseum and C. Marschallii, growing in the Caucasus region, Armenia and North- ern Persia. The heads are about the size of those of C. cinerarice- foliiim; the torus is dark brown ; the involucral scales and ray- florets are purplish-red ; the ovary is lo-ribbed. Insect flowers contain from a trace to 0.5 per cent, of a vola- tile oil, the Persian flowers containing the larger proportion, and the amount decreasing with the maturing of the flowers. They also contain two resins, varying from 4 to 7 per cent., the larger amount being found in the Dalmatian flowers ; a small quantity of a glucoside and a volatile acid. The principle toxic to insects is Pyrethron, an amber-yellow, CLASSIFICATION OF ANGIOSPERMS. 719 syrupy substance which is the ester of certain unidentified acids, and on saponification yields the alcohol pyrethrol which crystal- lizes in fine needles. The acids combined in the ester pyrethron do not give crystalline salts. Wormwood or Absinthium consists of the dried leaves and flowering tops of Artemisia Absinthium, a perennial, somewhat woody, branching herb, indigenous to Europe and Northern Africa, cultivated in New York, Michigan, Nebraska and Wis- consin and naturalized in the United States from plants that have escaped from cultivation. The leaves are grayish-green, gland- ular-hairy, I- to 3-pinnately divided, the segments being obovate, entire, or lobed ; the flowers are yellowish-green, the heads being about 4 mm. broad and occurring in raceme-like panicles ; the torus is hemispherical and the involucre consists of several series of linear bracts, the inner being scale-like; the florets are all tubular, the outer ones sometimes being neutral. The herb is aromatic and very bitter. The fresh drug contains about 0.5 per cent, of a volatile oil which is of a dark green or blue color, has a bitter, persistent taste but not the pleasant odor of the plant, and consists of d-tiuijone (absinthol), thujyl alcohol free and combined with acetic, iso- valerianic and palmitic acids, phellandrene and cadinene. The other constituents of the drug include a bitter glucosidal principle, ABSiNTHiiN, which fomis white prisms and yields on hydrolysis a volatile oil ; a resin ; starch ; tannin ; succinic acid, potassium succinate, and about 7 per cent, of ash. The plant is used in the preparation of the French liquor known as Absinthe. Artemisia Cina yields the official Santonin. Other species of Absinthium also yield volatile oils, as the Common mugwort {Artemisia vulgaris), which yields from o.^i to 0.2 per cent, of an oil containing cineol ; Artemisia Barrelieri, which contains an oil consisting almost entirely of thujone, and said to be used in the preparation of Algerian absinthe. Safflower consists of the dried florets of Carthamus tiiic- torius, an annual herb which is known only in cultivation. The florets are tubular, yellowish-red, the corolla tube being ahnut 2 cm. long and with 5 small, linear lobes ; the stamens are exserted. The ovary with the long^, slender style is usually not present in 720 A TEXT-BOOK OF BOTANY. the drug (Fig. 227, C). Safflower contains a small percentage of a yellow coloring principle (safBower-yellow), which is soluble in water, and 0.3 to 0.6 per cent, of a red coloring principle (car- thamin or carthamic acid), which is insoluble in water but soluble in alcohol, the solution having a purplish-red color. A volatile oil is also present. Carthamin is used in conjunction with French chalk in the preparation of a rouge. Tansy, the dried leaves and tops of Tanacetum vnlgare and var. crispnm, perennial, aromatic herbs indigenous .to Europe, extensively cultivated and naturalized in the United States. The leaves are large and pinnately divided, and the flowers, both tubu- lar and ligulate, are yellow, the heads being in terminal corymbs. The plant yields from o.i to 0.3 per cent, of a volatile oil, consisting of thujone, borneol and camphor; and 3 resins. Elecampane {Inula Heleniiun) is a large, perennial, densely pubescent herb with alternate leaves and large, solitary terminal heads, consisting of yellow tubular and ligulate florets (Fig. 227). The plant is indigenous to Central Europe and Asia, and natural- ized in North America from Canada to North Carolina. The root is used in medicine and was formerly official as Inula. The root of Polymnia Uvedalia, a plant closely related to Inula, but indigenous to the United States east of the Mississippi, contains a volatile oil, a glucoside, tannin, and a resinous sub- stance consisting of two resins, one of which is pale yellow and soft, the other dark brown and hard. The following Compositse, while not of very great importance, are used in some localities: Yarrow {Achillea Millefolium) is a conmion weed naturalized from Europe (Fig. 397) , and contains about o.i per cent, of a dark blue volatile oil with a strongly aromatic odor and a small amount of a bitter alkaloid, achilleine. The roots of yarrow, on the other hand, yield a volatile oil with a valerian-like odor. Achillea nobilis of Europe contains an oil resembling that of yarrow, but it is of finer quality and has a spice-like taste. Achillea moschata, an alpine plant of Europe, yields three alkaloids and a volatile oil containing cineol, and is used in Italy in the preparation of the liquor, ''Esprit d' Iva." Achillea tanacetifolia yields a blue volatile oil having the odor of tansy. CLASSIFICATION OF ANGIOSPERMS. 721 Fig. 397. Yarrow or Milfoil (Achillea Millefolium), a perennial herb, branching only at the top and bearing deeply pinnatifid leaves, the segments being very narrow. The flowers are small, white, occasionally crimson and arranged in large, terminal corymbs — Bureau of Plant Industry, U. S. Department of Agriculture. The High Golden-rod {Solidago cajiadoisis) yields 0.63 per cent, of a volatile oil, consisting chiefly of pinene, with some phcl- 46 'J22 A TEXT-BOOK OF BOTANY. landrene and dipentene, and containing about 9 per cent, of borneol, 3 per cent, of bornyl acetate and some cadinene. The True or Anise-scented Golden-rod (Solidago odora) yields an aromatic volatile oil and a small amount of tannin. Fig. 398. Method of gathering the pollen of Golden-rod (Solidago Shortii) for immuniz- ing the hay-fever horses. The plant is gathered just about the time that the pollen-sacs are ready to open, then taken to a sunny room — free from draft and air disturbances — placed slanting in a basin filled with water, the blossoms drooping over the sides of the vessel, with clean, smooth paper spread underneath them. The following morning the pollen will be on the paper and can readily be gathered with a feather-top or a quill. — After Schimmel & Co. The rhizome of the large Button-snakeroot (Lacinaria scari- osa), growing in the eastern and central portion of the United States and Canada, contains o.i per cent, of volatile oil, about 5 per cent, of resin, and 2 per cent, of a caoutchouc-like substance. CLASSIFICATION OF ANGIOSPERMS. ^2^ Coltsfoot (Tussilago Farfara) is a plant indigenous to Europe and naturalized in the Northern United States and Can- ada. It is an acaulescent herb with a slender rhizome 30 to 40 cm. long; nearly orbicular, somewhat lobed and tomentose leaves, and large, solitary, yellow flowers appearing before the leaves. The plant contains an acrid volatile oil, a bitter glucoside, resin and tannin. Echinacea is the root of Braiineria (Rtidbeckia) purpurea, a plant growing in rich soil from Virginia to Illinois and south- ward, and of B. angustifolia, growing from the Northwest Terri- tory to Texas (Fig. 399). The drug contains an alkaloid and 0.5 to I per cent, of an acrid resinous substance to which the medical properties are due. Rosin Weed or Compass Plant {Silphium laciniatuiu) , found growing from Ohio to South Dakota and south to Texas, produces an oleo-resin which exudes either spontaneously or from the punctures of insects, and contains about 19 per cent, of vola- tile oil, and 37 per cent, of acid resin. The Thistle {Cnicus benedictus) contains a crystalline bitter principle, cnicin, which is colored red with sulphuric acid. The Mexican drug pipitzahoac is the rhizome of Perczia Wrightii, P. nana and P. adnata, plants found in Southwestern Texas and Mexico. It contains about 3.6 per cent, of a golden- yellow crystalline principle, pipitzahoic acid, which appears to be related to oxythymoquinone and is colored an intense purple with alkalies and alkaline earths. Lion's foot, the root of Prenanthcs Serpcntaria, P. alba and other species of Nabalus growing in the United States, contains bitter principles, resin and tannin. Mio Mio (Baccharis cordi- folia), of South America, is poisonous to sheep and cattle and contains an alkaloid, baccharine, and a bitter principle. Spiny CLOTBUR (Xanthitim spinosum) contains a bitter resin and possi- bly a volatile alkaloid. The fruit of Xanthium spinosum, a common weed naturalized from Europe, contains an amorphous, non-glucosidal substance, xanthostrumarin, which forms precip- itates with a number of the alkaloidal reagents. Sneeze- weed {Helenium autumnale) contains a volatile oil. a bitter glucoside and tannin. Helenium tenuifolium, of the Southern United States, 724 A TEXT-BOOK OF BOTANY. Fig. 399. A flowering specimen of the Purple Cone-flower {Brauneria angustifolia), showing the 3-nerved lanceolate leaves and 2 of the flower heads with the characteristic long spreading rays. — After Newcomb. is a narcotic poison. Para cress (Spilanthes oleracea), of trop- ical America, contains a soft pungent resin and a crystallizable principle, spilanthin. The common white daisy {Chrysanthemum CLASSIFICATION OF ANGIOSPERMS. 725 Leucanthemum) yields about 0.15 per cent, of a greenish volatile oil with the odor of chamomile and mint. Chicory, the root of Cichorium Intybiis, a perennial herb with blue or purplish ligulate florets, indigenous to and cultivated in Europe and naturalized in the United States (Fig. 395), is used in medicine as well as in the preparation of a cofifee substitute. The root is spindle-shaped, somewhat resembling Taraxacum, but is of a light brown color and the laticiferous vessels are arranged in radial rows in the somewhat thinner bark. It contains a bitter principle and a large amount of inulin. In the preparation of a coffee substitute the root is cut into rather large, equal pieces and roasted, after which it is ground to a yellowish-brown, coarse powder. The grains are heavier than water, imparting to it a yellowish-brown color. Under the microscope it is distinguished by the branching latex-tubes and rather short, oblique tracheae with rather large, simple pores. The Sunflower (Helianthus annuus) is an annual herb indig- enous to tropical America and extensively cultivated. The plant is grown on a large scale in Russia, Hungary, Italy and India for its fruits, which yield a fixed oil resembling that of cotton seed. The achenes (so-called seeds) are obovate, flattened, externally black or with alternate white and black stripes, the pappus con- sisting of two deciduous, chaffy scales. Sunflower seed-cake is readily distinguished by a few of the fragments of the epicarp, with the characteristic twin, unicellular, non-glandular hairs and large, oblique, but rather short, sclerenchymatous fibers. Besides 40 per cent, of a fixed oil, the seeds contain a peculiar glucosidal tannin, helianthic acid, which is colored deep green with ferric chloride arid yellow with alkalies. The root contarns inulin ; the shoot asparagin, and the fresh pith about 1.5 per cent, of potas- sium nitrate. The pith has been used in the preparation of MoxA, a combustible vegetable material which burns without fus- ing and is used by the Portuguese to destroy any deep-seated inflammation. The pith of various species of Artemisia, which also contains considerable potassium nitrate, furnishes the Chinese Moxa. Jerusalem Artichoke {Helianthus tuber osus) is a large, coarse, pubescent herb with yellow ray-florets, which is indigenous 726 A TEXT-BOOK OF BOTANY. to the Middle United States and sometimes cultivated. The tubers, which resemble artichokes, are more or less elongated or pear-shaped, reddish-brown, somewhat annulate, and internally white or reddish. They have been used as a substitute for pota- toes and contain about i6 per cent, of the following carbohydrates : Inulin, pseudo-inulin, inulenin, saccharose, helianthenin, and syn- antherin. In early spring with the development of the tubers there is formed a small quantity of dextrose and levulose. The Globe artichoke of the gardens {Cynara Scolymus) is a hardy perennial and is valued on account of the fleshy involucral scales and torus, which are edible. The POLLEN of a number of plants of the Compositae, as rag- weed (Ambrosia), golden-rod (Solidago), aster and chrysanthe- mum, is said to be responsible for the autumnal cold, known as HAY FEVER. A similar disease is produced in spring and early summer by the pollen of certain grasses. It has been found that the pollen grains of these plants contain a highly toxic substance, belonging to the toxalbumins, which is the cause of the disease. By inoculation of rabbits, goats and horses with this toxalbumin a serum containing an antitoxin is obtained which neutralizes the pollen toxin and protects those who are susceptible to hay fever from its attacks. In practice the serum is prepared by injecting the toxalbumin subcutaneously into horses, the serum being known in commerce as pollantin (Fig. 398). The pollen of the following plants is toxic : aster, barley, chrysanthemum, convallaria, corn-flower, golden-rod, grasses, honeysuckle, oats, Oenothera, ragweed, rice, rye, spinach, wheat, and zea. The constituents of rye pollen are 86.4 per cent, of organic matter, 10.2 of water, and 3.4 of ash. The organic matter consists of 40 per cent, of toxic substances, 3 of fixed oil, 25 of carbohydrates, and 18 of a non-albuminous substance. The num- ber of pollen grains per gram varies in different plants : from Indian corn being 7,000,000, of rye 20,000,000, of golden-rod 80,000,000, and of ragweed 90,000,000. The flowers of the Japanese chrysanthemum " Riuno-kiku " (Chrysanthemum sinense japoniciim) yield 0.8 per cent, of a volatile oil containing an optically inactive crystalline iso-camphor. CHAPTER VI. CULTIVATION OF MEDICINAL PLANTS. When the forests and woods were full of wild medicinal plants that could be easily gathered, there was hardly an incentive to consider the farming of them. Now that they are becoming scarcer, the need is especially apparent. Our interest in the culti- vation of medicinal plants, however, is not primarily because there is a growing scarcity of the sources of supply, but in order that drugs of uniform quality and increased value may be had. For- tunately, there is a tendency on the part of some manufacturing pharmacists to concentrate their efforts upon a few plants yielding drugs and to study them in relation to their active principles throughout different periods of the season. In addition to these actual experiments, there are numerous inquiries made regarding the possibilities of the successful farming of medicinal plants. These inqtiiries come from various people who, for one reason or other, would like to get into country life and have some definite work to do. Many of them have never had any practical experi- ence in growing plants other than taking care of a garden plot. Nearly all know nothing of the commerce of drugs and have no idea of the problems connected with the disposition and marketing of them. Fortunately, some experiments have been conducted and there is some general information as to how one should proceed in the work. However, it must be said at the outset, no one can grow medicinal plants without having some training and special education for it ; and unless one is familiar with the prac- tical conditions of trade, that is in regard to the markets and prices paid for drugs, even though successful in raising a good crop, one may not be able to dispose of it. It is very difficult to lay down any one rule that can be invariably followed on this sub- ject. In fact, very little work has been done to enable us to draw other than very broad conclusions. The first thing to be consid- ered is locality. Of course, tropical plants would not grow in the temperate zone, nor mountainous plants at the seaside, although even here there are exceptions that only experiments can show 727 728 A TEXT-BOOK OF BOTANY. Then again, there are plants which grow only in the rich woodland soil, while others grow in barren soil in open places. Some plants require special kinds of soil, as Atropa Belladonna and Cannabis sativa, which do not seem to reach a high state of cultivation except in a calcareous soil. On the other hand, the plants of the Ericaceae are peculiar in that they require an acid soil (pp. 250, 656). In beginning this work in a new locality it is very important to make a rather careful survey of the plants growing wild, or those which have become naturalized. It would be safe to say that within certain limits, if there are a number of genera of any family well represented that has some of the habits of the plant with which one desires to experiment with, there is a probability that it may be grown successfully. This can be ascertained to some extent by the nature of the plants that are brought under cultiva- tion. For instance, digitalis might be grown very successfully in localities where it is cultivated and has become naturalized. By a priori reasoning, in the cultivation of licorice, the ideal location for growing the plant would be in the West and North- west where the wild licorice, Glycyrrhiza lepidota, is indigenous. In addition, it is necessary to study the best ways of propagating the plant one wishes to grow. Sometimes this is by means of seeds, as in belladonna and digitalis ; at other times it is by propa- gation of rhizomes, as hydrastis and glycyrrhiza ; or again by root-stocks or prostrate stems, as in the mints. Sometimes both seeds and cuttings may be used, as in the case of hydrastis. Plants Grown from Seeds. — A large number of plants can be grown from seeds, and when they are grown in this manner, espe- cially in a temperate climate, where the growing season is rather short, it is necessary to begin the germination of the seed early in the spring. This must be done in the house or under conditions where there is some protection. They may be sown either in small boxes or seed pans, in which the soil is quite sandy or made up largely of broken granitic rock (Fig. 400), and which must be clean and free from organic matter that is likely to mould. The seeds should not be planted too deep, and the boxes or pans should be covered with glass so as to condense or hold moisture. Of course, where there is the necessary attention, so far as keeping the earth moist is concerned, this can be dispensed with. The CULTIVATION OF MEDICINAL PLANTS. 729 Fig 400 Digitalis Seedlings in seed pans, ready to be transplanted into plant flats. mrll^:''l'1 m H^f^l Fig. 408. Atropa Belladonna, first year's growth from seed planted January ist. Photograph in July of the same year. — From the Experimental Farm of Eli Lilly & Com- pany, Indianapolis, Ind. year leaves, and might be used in preparing assayed digitalis prepa- rations." This means that one does not have to wait two years before securing a crop, so that practically one can obtain twice the quantity of the drug during the same period. There may be some instances during this experimental stage which might seem to indicate that certain external conditions, such as climate as well as soil, have a very great influence in the growing of plants of exceptional value. In the case of American-grown cannabis, Eckler and Miller have shown that repeated plantings CULTIVATION OF MEDICINAL PLANTS, 741 from carefully selected plants of American and Indian cannabis have failed to yield, when in cultivation near Indianapolis, a product testing over 65 per cent, of the active value of good Indian-grown drug, and that the majority of the plants tested 50 per cent, and even less. Pig. 409. Form of American Cannabis developed by F. A. Miller. Such forms are obtained by selection and result in strains that are better adapted to modern methods ol agriculture and from which the collection of the pistillate inflorescence is greatly simplified. — From the Experimental Farm of Eli Lilly & Company, Indianapolis, Ind. Experiments conducted near Timmonsville, S. C, by the U. S. Department of Agriculture have shown that in that locality a drug of a somewhat higher degree of potency can be grown. Of course, it is well known that the hemp plant is grown extensively for fiber in Kentucky and other parts of the middle West. This 742 A TEXT-BOOK OF BOTANY. may be due in large part to the fact that it requires a limestone soil, and in practice the most favorable results are obtained where there is an underlying bed of blue limestone. Sufficient has been said to show that success will attend the cultivation of medicinal plants, and indeed, by a priori reasoning on the basis of other Fig. 410. Form of American Cannabis developed by F. A. Miller. Such forms are obtained by selection and result in strains that are better adapted to modern methods of agriculture and from which the collection of the pistillate inflorescence is greatly simplified. — From Experimental Farm of Eli Lilly & Company, Indianapolis, Ind. agricultural efforts, one would expect that medicinal plants could be grown with the same certainty of increasing the yields of any particular constituent or quality that might be desired. Indeed, the history of the sugar beet industry has been duplicated in the work on Cinchona, and the sam_e thing can be said with regard to any other plant that man desires to conserve and cultivate. There CULTIVATION OF I^IEDICTNAL PLANTS. 743 are no insurmountable obstacles in this work, and there are no in- tricate processes to be solved before success results. There are merely a few underlyin^^ principles that must be adhered to. and by persistent effort and with a full understanding of market con- ditions success must crown the efforts of anyone who undertakes Fig. 411. A seedling plant of Digitalis about six months old. this work. What has been done in the selection of fruits and vege- tables can be equally well accomplished in drugs with the proper incentive. Progress in the United States.— We can scarcely appreciate that while the development of medicinal plant culture has been 744 A TEXT-BOOK OF BOTANY. an exceedingly slow one, yet as a matter of fact, by reason of some of the products being more extensively used, as in the case of hops, it is one of the oldest agricultural industries in the United States. The history of the cultivation of hops is very similar to Fig. 412. Cannabis satlva: Young plant grown from seed found in the drug Cannabis indica. the experience with other medicinal plants. For instance, it was grown in Virginia with poor results, and in Vermont and Massa- chusetts, where it was very successful. By virtue of the success obtained in the New England States it was, in the early part of the last century, introduced into New York State and later spread CULTIVATION OF MEDICINAL PLANTS. 745 into some of the Middle States, as Michigan, Wisconsin. Indiana, and Ohio. Since that time the cultivation has been extended to Fig. 413. Seedling plants of Erytlnoxvloii Coca (A) ami I'ucufvttus (ilohulus (in some of the States on the Pacific coast, notably Oregon, Washing- ton, and northern California. The peppermint industry shows a similar history. This indus- try was first developed in Wayne County, New York. Later it 746 A TEXT-BOOK OF BOTANY. spread into Michigan, Ohio, and some of the Southern States, and by reason of the more favorable climate and soil conditions in ^Michigan the industry here has outstripped that of even New York State, being practically abandoned in Ohio and the other States. The men connected with the Division of Botany of the United States Department of Agriculture have always mani- fested a keen interest in the possibilities of the cultivation of medicinal plants, and have done wdiat they could to encourage interest in this subject, and the records show that they have sup- plied information as it might be needed by those disposed to take up the work in a practical manner. The development of the tea industry in North Carolina is one of the most creditable pieces of work of the National Govern- ment. Bulletin No. 234 of the Bureau of Plant Industry, on " The Cultivation and Manufacture of Tea in the United States," by George F. Mitchell, should serve as an inspiration to anyone contemplating drug culture. If a plant of this kind can be grown successfully here and the technique of manufacture developed to such an extent that the cultivation at Pinehurst, North Carolina, has become remunerative, there is no question but that within reasonable limits nearly any plant except the strictly tropical ones can be successfully grown in the United States. Without doubt, the camphor industry will become successful in some of the Southern States. Nearly fifty years ago, when the price of camphor was very high, the government started some experiments in Florida in the growing of the camphor tree. These experiments were subsequently abandoned, as there was hardly any likelihood of anyone being interested in this commercially on account of the low price of camphor. During the past few years, however, interest in this culture has been revived in Florida and southern Georgia by reason of the fact that frosts destroyed the citrus fruits and the landowners began a search for other possible crops which would not be so injured. Circular No. 12, Division of Botany, United States Department of Agriculture, shows just what can be done for the successful cultivation of this tree in the Southern States, and some recent experiments of the government show that by utilization of leaves and twigs there are great possi- bilities in the economical manufacture of camphor in the United States in spite of the high price of labor. CULTIVATION OF MEDICINAL PLANTS. 747 Owing to the fact that essential oils are used in such large quantities it is quite likely that the cultivation of many of these plants may be made successful, providing at the same time that suitable apparatus for their distillation is also installed upon the farms. By reason of the fact that the cultivation of chicory is a per- manent agricultural industry in nearly all of the countries having a temperate climate in Europe, experiments have been conducted in the United States in a small way, and these have led to the con- clusion that it may be successfully cultivated in those States where the sugar beet industry has flourished. As a summary, the following general points might be held in mind by those who desire to take up the cultivation of medicinal plants : In the first place, he ought to determine whether there is a market for any drug under consideration, and this can only be obtained by personal inquiry and investigation, as not even any of the government publications give this information. In the next place, if one is satisfied that it is worth while to take up the cultivation of any particular plant, its geographi- cal range should be studied, both as to where it is indigenous and where it has become naturalized. The literature should be gone over not only for facts regarding the cultivation and distribu- tion of the particular plant in view, but also of some of the related plants. At the sarhe time that these preliminary studies are made, a careful survey should be taken of the plants which are indigenous and under cultivation in the particular locality where one is pro- posing to locate the farm. Then, of course, everything should be done on a small scale at first. If there is no information available, then he must, on the basis of the general principles laid down for the cultivation of medicinal plants, proceed with their culture, conducting parallel experiments with propagation by both seeds and cuttings. Then when the crop is harvested he must, by analytical and other means, satisfy himself as to the value of his product com- pared with the commercial article, and with these facts in hand submit specimens and request quotations from the dealer in crude drugs, and the wholesale druggist. On this basis he will arrange 748 A TEXT-BOOK OF BOTANY. for all future crops with some certainty as to their market value. Experience has shown that cultivated crops command a higher price than the drugs obtained from wild plants, even though their superiority cannot always be demonstrated by analytical means. For instance, no one is trying to determine by an analytical proc- ess whether any given lot of tobacco, tea, or coffee is of superior value, and yet the competent dealer and the discriminating public even recognize the qualities of the grades that are offered. This is even more marked with the products that have been derived thus far from cultivated medicinal plants, and are appreciated by some pharmacists and physicians. BIBLIOGRAPHY. Cultivation of Belladonna : Vreven and Schreiber, Schweiz. Wochenschr. Chcm. It. Pharm..igji,p. 37^; Borneman, Amer. Jour. Pharm., 1912, p. 549; Miller, Ibid., 1913, p. 291, also Bull. Torrey Bot. Club, 1914, p. 118; Carr, Amer. Jour. Pharm., 1913, p. 487; Newcomb, Ibid., 1914, p. 531, and 1915, p. I ; Sievers, Ibid., 1914, pp. 97 and 483, and 1916, p. 193. Cultivation of Digitalis: Farr, Pharm. Jour., 1907, XXIV., p. 198: Newcomb, Amcr. Jour. Pharm., 1911, p. 529; Borneman, Ibid., 1912, p. 547; Miller, Ibid., 1913. P- 297. Cultivation of Hydrastis: John UrI Lloyd, Proc. A. Ph. A., 1905, p. 307, and in Jour. A. Ph. A., Vol. I, p. 5 ; Alice Henkel and G. Fred. Klugh, Circ. No. 6, Bureau of Plant Industry, U. S. Department of Agriculture; J. C. Baldwin, Amcr. Jour. Pharm., April, 1913, p. 147. Cultivation of Ginseng: George V. Nash, Bulletin No. 16, Division of Botany, U. S. Department of Agriculture. Cultivation of Eucalyptus: A. J. McClatchie, Bulletin No. 35, Bureau of Forestry. U. S. Department of Agriculture. Cultivation of Hyoscyamus: Mitlacher, Zcitschr. Oest. Apoth. Ver., 1912, p. 401 and Pharm. Post, 191 1, p. 214; Borneman, Am..er. Jour. Pharm., 1912, p. 551; Miller, Ibid., 1913. p. 295; Carr, Ibid., 1913, p. 487; Newcomb, Ibid., 1914, p. 531, and 1915, p. i; Newcomb and Haynes, Ibid. 1916, p. i. Cultivation of Peppermint: A. M. Todd, Proc. A. Ph. A., 1903, p. 277; Alice Henkel, Bulletin No. 90, Bureau of Plant Industry, U. S. De- partment of Agriculture. Cultivation of Cannabis Sativa : C. R. Eckler and F. A. Miller, Amer. Jour. Pharm., November, 1912. Cultivation of Camphor: Circ. No. 12, Division of Botany, U. S. De- partment of Agriculture. Cultivation of Tea : Bulletin 234, Bureau of Plant Industry, U. S. De- partment of Agriculture. CHAPTER VII. MICROSCOPIC TECHNIQUE AND REAGENTS. Making of Sections. — In order to examine objects by means of the compound rnicroscope they must be relatively thin and transparent ; furthermore, they must be mounted in water or other mounting fluids. In material consisting of single cells, or, at most, a layer of a few cells, the specimen may be mounted directly in water. This manner of mounting may also be used in the exam- ination of pollen grains, hairs, and thin organs, as petals. Usually in the examination of the latter some clearing agent, as solution of hydrated chloral, is necessary in order to make the specimen trans- parent. As most objects consist of a large number of cells, it is necessary to examine small portions of them, and these are termed sections. They are made with a razor and correspond to the shav- ings made by a carpenter's plane. As each object has three dimen- sions, it is necessary that three different kinds of sections be made, (i) A transverse or cross section is one made horizontally through the object, therefore its plane lies at right angles to the long axis. (2) A radial-longitudinal section is one made at right angles to the cross section and it lies in the plane of the radius, so that in a dicotyledonous stem the section would be made parallel with the medullary rays. (3) A tangential-longitudinal section differs from the preceding in that it lies parallel to the outer surface of the object, or in a plane tangent to the cylinder. These several forms of sections are readily understood from the adjoining illus- tration (Fig. 414). Sections of roots, stems, barks, and many fruits and seeds can be made directly without embedding the. material, and while sections can be made holding the material in the hand, between the thumb and three fingers, the hand microtome for holding the material may be used by those who are less experienced. In the sectioning of leaves and other material that is not firm, and fruits and seeds which are too small to hold in the hand, the material should be embedded in some substance whicii will hold it and give it stability. When the tissues are not too hard the 749 750 A TEXT-BOOK OF BOTANY. material may be placed between pieces of elder or sunflower pith. In some cases the making of sections is facilitated by moistening both the pith and the razor. In the case of seeds and fruits which are very small and at the same time very hard, as colchicum and mustard, it is best to use a velvet or fine grade of cork for holding the material. The cork is indented by means of forceps and the seed or fruit forced into the cavity. In the case of very delicate tissues, where the protoplasmic contents of the cells are to be studied, as in the ovaries of flowers, prothalli of ferns and other parts of the plant, where cell division is going on, the material should be embedded in paraffin or celloi- FiG. 414. Schematic presentation of the three types of sections: q, cross or transverse sec- tion; I, radial-longitudinal section; /, tangential-longitudinal section. — After Meyer. din, subsequently hardened, and sectioned by means of a finely adjusted microtome. Dried AIaterial. — Most of the vegetable drugs and some of the vegetable foods occur in commerce in a more or less dried condition, and in order to study them microscopically it is usually necessary to give them some preliminary treatment. With the majority of drugs, soaking in hot or cold water from a few minutes to a few hours will render them sufficiently pliable or soft for sectioning. After this the material is hardened by placing it in alcohol (60 to 70 per cent.) for a few hours or over night. It may then be sectioned and treated with special reagents or stains as desired. \"ery hard material, as the shells of nuts and MICROSCOPIC TECHNIQUE AND REAGENTS. 751 seeds, may be softened by soaking in solutions of potassium hydrate. Some Practical Suggestions. — The following are some of the rules which should be borne in mind by the student when using the microscope in the examination of microscopic material : 1. Always mount the sections (including powdered material) in water or other suitable reagent prior to examination; never attempt to examine dry material except in special cases. 2. Use sufficient of the mounting medium or reagent to cover the specimen, but avoid an excess or more than will be held under the cover-glass. 3. Always endeavor to. have the object properly illuminated by making use of the concave mirror. 4. Always be particular about having the eye-piece and objec- tives clean. 5. In examining a microscopic object, always use the low- power objective first. 6. The edge of a section is always the thinnest, and this part being the best for study, should be brought to the center of the field. 7. When the object is properly centered, raise the objective, swing it to one side, bring the high-power objective into its place, and cautiously lower it until it is brought to about the distance of a millimeter from the cover-glass. Then holding the slide with the left hand, the proper focus of the object is obtained by making use first of the coarse adjustment and then of the tine adjustment, the right hand being used for this purpose. In exam- ining the object always hold the slide with the left hand, and use the right hand for maintaining the proper focus by means of either the coarse or fine adjustment. 8. In all cases where practicable make drawings of the sections examined. 9. In some cases it is desirable to apply a reagent after the material has been mounted, as in the addition of an iodine solution to a section to determine the presence of starch, and this is accom- plished by placing a drop or two of the reagent, by means of a pipette or dropper, near the edge of the cover on one side and 752 A TEXT-BOOK OF BOTANY. taking up the excess of liquid by temporarily placing a piece of filter paper on the opposite side (Fig. 415). Air-Bubbles. — The beginner in the use of the microscope is often confused by the presence of air-bubbles, mistaking them for portions of the material under examination, as starch grains, oil-globules, or even the cells themselves. While it is not prac- ^ , [^ -~^.s^^ ^ s Fig. 415. Method of applying reagent to material already mounted, g, pipette; f, filter paper. ticable to avoid their presence entirely, their identity may be determined by the manner . of focussing upon them. When focussing above on an air-bubble it always appears dark (Fig. 416, C), but when the focus is lowered, it becomes lighter (Fig. 416, D) ; while in the case of an oil-globule or starch grain the reverse is true, i.e., it is lightest when the focus is above (Fig. MICROSCOPIC TECHNIQUE AND REAGENTS. y^Z 416, E) and darker when the focus is lowered (Fig. 416, P). To obviate as much as possible the formation of air-bubbles, the edge of the cover-glass should first be applied to the liquid on one side and then allowed to drop upon it. When particular care is required, a pair of forceps may be used for holding the cover and lowering it gradually. i Fig. 416. Diagrams showing the difference between an air-bubble and an uil-globule in different foci: When the focus is above, as at A, the air-bubble (C) is dark gray and the oil-globule (E) light gray. When the focus is at the lower portion, as at B, the air- bubble (D) is light in the center and the oil-globule (F) dark gray. The same optical effects as are obtained with oil-globules are observed with cell walls, starch grains and crystals. Frequently also simple pores in the cell-walls are mistaken for cell-contents, and sometimes even the lumen of the cell has been mistaken for a prism of calcium oxalate. The beginner will therefore find it an advantage to study the simple pores ir. the pith cells of elder or sassafras (Fig. 132). In sections show- ing either the upper or lower wall of the cells, the pores appear as circular or elliptical markings, which may be mistaken for cell- 48 754 A TEXT-BOOK OF BOTANY. contents, but which in focussing upon them are seen to be optical or microscopical sections of the pores. Micrometry or Microscopic Measurement. — In the micro- scopic study of any substance a knowl- edge of the comparative size of the elements is often of much help in deter- mining the identity of material under examination, 'and for this reason the student should early learn to measure the characteristic elements, or those showing a variation in size in different plants, as starch grains, calcium oxalate crystals, diameter of cells, thickness of cell-walls, etc. The method best adapted for this work is that involving the use of a micro- metric scale which is placed in the eye- piece and known as the ocular micrometer. But to determine the value of the ocular micrometer it is necessary to use another scale known as the stage micrometer. The stage micrometer, as its name indi- cates, is used on the stage, and when placed in juxtaposition to an object indi- cates its size. However, it is obviously impracticable always to place an object alongside of the scale, and hence in prac- tice the ocular micrometer is used, the value of the divisions of which are scop?'showin|The°?e'iitk>n'^of determined by comparison with those of the ocular micrometer (o) and ^i . • , / t^' ^\ t-i the stage micrometer (s). As the stagc micromctcr (Fig. 417). The oTthrScSlvllt\Qlve''e<^nWa. valuc of the divisious of the ocular scale lent to 4 divisions of the stage • r j*rc i. i, • i* micrometer, and thus each di- vanes for different objcctivcs, eye-pieces vision of the ocular is equiva- j i. u 1 i-t t. v • j. lent to 2 microns (see p. 813). and tubc lengths, hcucc it IS uccessary to d, diaphragm in eye-piece, i. • j.i 1 r i.u j* • • r xU on which the ocular microm- asccrtaiu the valuc of the divisions for the different optical combinations and tube lengths employed. The stage micrometer is usually divided into tenths and hundredths of a millimeter, and the millimeter being equivalent to looo microns (the micron being indicated by the MICROSCOPIC TECHNIQUE AND REAGENTS. 755 Greek letter /x), the smaller divisions are equivalent to 10 microns (lO/x). For example, suppose, using a low-power objective, that 10 divisions of the ocular scale equal 20 of the smaller divisions of the stage micrometer. Thus, 20 divisions of the stage micrometer are equivalent to 20 times 10 /x , or 200 /x; then, since 10 divisions of the ocular scale equal 20 divisions of the stage micrometer, one division of the ocular scale is equivalent to i/io of 200 /x, or 20 fi. Or, using the high-power objective, we may suppose that 80 divisions of the ocular scale equal 24 divisions of the stage micrometer. Thus, i division of the ocular micrometer is equivalent to I/80 of 240 fx, or 3 /x. Then, if an object has a diameter covering 3 divisions of the ocular micrometer, its diame- ter is equivalent to 3 times 3 /x (the value of one division), or 9 /a. Reagents. — The reagents that have been recommended for microscopical work are quite numerous, and, while nearly all of them may have more or less special merit, the number of reagents actually required in practice is fortunately quite small. It is important that the student recognize the necessity for a thorough understanding of the structure of the material under examination rather than place too much dependence upon the effects produced by reagents ; in other words, the study of struc- ture should precede the use of reagents, particularly stains, when it will often be found that the latter can be dispensed with entirely. The chemicals that are employed in microscopical work, either as reagents or for other purposes, may be classified as follows : (i) Preservatives, (2) Fixing and Killing Agents, (3) Harden- ing and Dehydrating Agents, (4) Clearing Agents, (5) Stains, and (6) Special Reagents. Preservatives are substances used to preserve material which is to be examined. The most important of these are alcoiiol [ from 40 to 95 per cent.) and formalin [2 to 6 per cent, aqueous or alcoholic (60 per cent, alcohol) solution], the latter of which is considered advantageous in the preservation of specimens contain- ing coloring substances, as leaves, flowers, etc. Almost any anti- septic of the proper strength may be used as a preservative. Fixing or Killing Agents are more especially employed in the study of the protoplasmic cell-contents, where by their use the life-processes of the cell are brought to a sudden termination. 756 A TEXT-BOOK OF BOTANY. the object being to fix the contents in a condition approaching as nearly as possible the normal living state. In order to carry out this operation successfully, the living specimen must be placed in the fixing or killing agent as soon as collected, and if the specimen is large it should be cut into small pieces. The following are some of the common fixing agents : Chromic acid in 0.5 to i per cent, aqueous solution ; osmic acid in i to 2 per cent, aqueous solution ; Flemming's mixture, v^hich is an aqueous solution of chromic acid (0.25 per cent.) containing o.i per cent, of osmic acid and 0.1 per cent, of acetic acid; picric acid in concentrated aqueous or alcoholic solution ; picric-sulphuric acid, a concentrated aqueous solution of picric acid containing 2 per cent, by volume of sulphuric acid: and mercuric chloride (corrosive sublimate) used in o.i to I per cent, aqueous or alcoholic solution. Hardening or Dehydrating Agents are those substances which are employed for the purpose of hardening the specimen so as to facilitate sectioning and for removing the water, which would interfere with its examination. Alcohol is to be regarded as the principal hardening or dehydrating agent, and considerable care is necessary in its use; the specimen is treated successively with alcoholic solutions of gradually increasing strength, begin- ning with a 35 per cent, solution, in which the specimen is kept for twenty-four hours ; then it is placed in 50 per cent, alcohol for from six to twenty-four hours, and then in 70 per cent, alcohol, in which it may be kept until ready for use. In order to avoid shrinking of the material at this stage, it may be kept in a solu- tion of alcohol and glycerin, or oil of bergamot, or a mixture of xylol and paraffin. When the material is to be examined it should be removed to 85 per cent, alcohol for from six to twenty- four hours, then to 95 per cent, alcohol and absolute alcohol suc- cessively for the same length of time. Of the other dehydrating agents the most important are anhydrous glycerin, pure carbolic acid, and anhydrous sulphuric acid, the latter being used in a desiccator and not applied directly to the specimen. Clearing Agents. — Most dehydrating agents are also clear- ing agents, because of the fact that the air and water in the speci- men are replaced by a medium having greater refractive proper- ties. Some clearing agents act chemically on the tissues and cell- MICROSCOPIC TECHNIQUE AND REAGENTS. 757 contents. Among the clearing agents most frequently employed are: Chloral in saturated aqueous solution, and chloral-glycerin solution (a solution of equal parts of glycerin and water saturated with chloral). Essential oils, as clove, turpentine, cedar, mar- joram, etc., are also useful for this purpose, particularly when the specimen is to be mounted in Canada balsam. Staining Agents are those that produce more or less defi- nitely colored compounds with the cell-contents or -walls. They include: (i) the Aniline Dyes and (2) Non-aniline Stains. The aniline stains may be used in aqueous solutions, weak alcoholic solutions or strong alcoholic solutions, containing from I to 3 per cent, of the dye. The following are the aniline stains most frequently employed : Aniline blue, Bismarck brown, fuchsin, gentian violet, methylene blue, methyl violet and safranin. In addition to these, aniline hydrochloride or sulphate is used in what is known as Wiesner's Reagent, which is a 25 per cent, solution of alcohol containing 5 per cent, of either of these salts, a drop of either hydrochloric or sulphuric acid being used with a drop of the solution, according as the hydrochloride or sulphate has been used. Loffler's Methylene Blue. — This reagent is prepared by adding 30 c.c. of a concentrated alcoholic solution of methylene blue to 100 c.c. of water containing 10 milligrams of potassium hydrate. Ziehl's Carbol-fuchsin. — This solution is prepared by add- ing 15 c.c. of a concentrated alcoholic solution of fuchsin to 100 c.c. of water containing 5 grams of carbolic acid. Aniline Dyes are usually employed in concentrated aqueous solution, but owing to the difference in solubility of the dyes the solutions vary in strength. Saturated solutions of eosin or gen- tian violet may be prepared by dissolving i gram of the dye in 100 c.c. of water, while to make a saturated solution of methylene blue requires 0.400 Cm. of the dye to 100 c.c. of water. Some investigators prefer to replace the distilled water with aniline water, which is prepared by adding about 3 grams of anilin oil to 100 c.c. of distilled water. Reagent Bottle for Sterile Solutions. — The solutions of the aniline dyes as ordinarily prepared deteriorate more or less rapidly and are usually made up fresh each time they are required 758 A TEXT-BOOK OF BOTANY. for use. These solutions, as well as other reagents that are prone to decomposition, may, however, be kept for months or even years by preparing them with care and keeping them in a special kind of bottle (Fig. 418). An ordinary bottle may be used, and is fitted with a rubber stopper perforated so as to allow the intro- duction of two glass tubes. These tubes are bent twice at right angles and the free ends directed downwards. One of the tubes is connected with an atomizer bulb and serves for forcing out the Fig. 418. Reagent bottle for sterile solutions, liquid. A small plug of absorbent cotton is placed in the tube at the point C, so as to filter the air. This may be improved by blowing a bulb in the tube for holding the cotton. The bottle should be sterilized before placing the solution in it, and the solu- tion should be made by adding the dye to sterile water contained in the bottle. The solution may be afterwards further sterilized by means of steam if this should be found necessary, as in this way only a perfectly sterile solution could be produced. MICROSCOPIC TECHNIQUE AND REAGENTS. 759 iodide Sulphuric acid water Chloral solution or potas- sium hy- drate solution Phloro- glucin and hydro- chloric acid Anilin sul- phate and sulphuric acid Iodine solution Chlor-zinc- 1 ct- Starch Grains Brings out the structure Swell and finally dis- solve The acid brings out the structure of the grains, finally dis- solving them The acid brings out the structure of the grains, finally dis- solving them Pale blue to bluish-black, depending upon the strength of reagent Swell and are colored blue Dissolve Causes sep- aration of calcium sul- phate needles Clears the sections, bringing out the defi- nition of the crystals The acid dissolves the crystals Cause the separation of fine needles of calcium sulphate Clears the tissues, bringing out the lamellce and pores The walls become purplish-red The walls become bright- yellow The walls turn yellow The walls turn yellow- ish- to red- dish-brown Swell and finally dissolve i ST Clears the tissues, bring- ing out the markings of the walls The walls become purplish-red The walls be- come bright yellow The walls turn yellow- ish-brown The walls turn yellow- ish-brown Swell and dissolve slowly i 3 i I: 1 Clears the tissues, bring- ing out the pores The walls may or may not be colored purplish-red The walls may or may not be col- ored bright yellow The walls turn yellow- • ish-brown The walls turn yellow- ish- to red- dish-brown Swell and finally dissolve It Has a clearing effect, and swells the walls The walls are colored yellow The walls become lavender or violet Dissolves I 3 Become yellow The walls are colored yellow The walls become yellowish- brown Dissolve very slowly 0? ''I Dissolves the ground-mass, bringing out the defini- tion of the crystalloids Dissolve The acid has a sol- vent effect The acid has a sol- vent effect The crystal- loids are colored yel- lowish or yellowish- brown Become yellowish- brown. Dissolve Dissolve slowly 0 II Swell and finally dissolve Become yellowish Become yellow Dissolve slowly Protoplas- mic Contents ;6o A TEXT-BOOK OF BOTANY. The non-aniline stains give, as a rule, more reliable and con- stant results in the study of cell-walls, as in the roots, stems, and other parts of the plant, than tiie aniline stains. They include the following: Beale's Carmine Solution, which is made as follows: Mix 0.6 Gm. carmine with 3.75 Gm. ammonia water (10 per cent.) ; heat on a water-bath for several minutes ; then add 60 Gm. of glycerin, 60 Gm. of water and 15 Gm. of alcohol, and filter. Grenacher's Borax-Carmine Solution. — Dissolve 2 to 3 Gm. of carmine and 4 Gm. of borax in 93 c.c. of water and then add 100 c.c. of alcohol (70 per cent.) ; shake and filter. When this stain is employed the sections are freed from an excess by the use of alcoholic solutions of borax or oxalic acid. Hover's Picro-Carmine Solution is made by dissolving carmine in a concentrated solution of neutral ammonium picrate. A solution of carmine and picric acid is known as Picro-Carmine Solution. Carmine solutions give to cellulose, the nucleus and proteins a red color. Chlor-zinc-iodide Solution, or Schulze's Cellulose Reagent, consists of anhydrous zinc chloride, 25 Gm. ; potassium iodide, 8 Gm., and water, 8.5 Gm., to which as much iodine is added as the solution will dissolve. This reagent gives a violet color with cell-walls containing cellulose. Of the cell-contents, starch is the only one which is affected by it, being colored blue. Bohmer's H.ematoxylin Solution is prepared by mixing the two following solutions and filtering after allowing the mix- ture to stand for several days: (a) one part of a 3.5 per cent, alcoholic (95 per cent.) solution of hsematoxylin and (b) three parts of a 0.4 per cent, aqueous solution of potassium alum. Delafield's H.ematoxylin Solution, which is also incor- rectly called " Grenacher's Haematoxylin Solution," is made by mixing the following solutions: (a) Haematoxylin 4 Gm., alcohol 25 c.c, and (b) 400 c.c. of a saturated aqueous solution of ammo- nia alum ; this solution is exposed to the light for three or four days, filtered, and then 100 c.c. each of glycerin and methyl alco- hol are added, the solution allowed to stand for several days and finally filtered. An excess of the stain is removed from the sec- tions by subsequent washing either with a 2 per cent, alum solution MICROSCOPIC TECHNIQUE AND REAGENTS. 761 or an acidified alcoholic solution. This solution gives to cellulose, lignin and the protoplasmic cell-contents a violet color. Iodine and Potassium-Iodide Solution consists of iodine, 2 Gm. ; potassium iodide, 6 Gm. ; water, 100 c.c. Iodine Water is prepared by adding as much iodine to dis- tilled water as it will dissolve (about i : 5000). Chloral-Iodine Solution consists of a saturated aqueous- solution of chloral, to which iodine is added. This reagent is useful for staining the starch grains in the chloroplasts. Phloroglucin Solution, used as a test for lignin, is a 0.5 to 2 per cent, alcoholic solution of phloroglucin, which is used in conjunction with hydrochloric acid. The reagent should be protected from light. Iron Solutions are aqueous or alcoholic solutions containing 5 tO' 20 per cent, of ferric acetate or ferric chloride. Tiiese are mostly used as tests for tannin, giving either a bluish-black or greenish-black coloration or precipitate. Copper-Acetate Solution is a 7 per cent, aqueous solution of cupric acetate. It is the most distinctive test for tannin, par- ticularly with fresh material, producing a reddish-brown precipi- tate in the cells containing tannin. The fresh material should be cut into small pieces and immediately placed in the solution of copper acetate and allowed to remain for from 24 to 48 hours. The excess of the reagent is then washed out and the material placed in alcohol. Schulze's Macerating Solution is prepared by adding crystals of potassium chlorate from time to time to warm con- ceiitrated nitric acid. It is employed in the isolation of lignified cells. The material is allowed to remain in the solution for a short time or until there appears to be a disintegration of the tissues. A large excess of water is then added. The material is carefully washed, the cells teased apart and mounted in a solution of methylene blue. Special Reagents comprise all those substances which are employed in the morphological study of the cells, and include solutions of the alkalies (o.i to 6 per cent.) solutions of the mineral acids, which may be weak or concentrated, and solutions of organic acids, as acetic and citric. "^^2 A TEXT-BOOK OF BOTANY. Double Staining, or the use of two stains in the examination of a specimen, furnishes not only a means of beautifying the speci- men, but also has a certain diagnostic value. The following are some of the combinations used: (a) aqueous solutions of car- mine in connection with alcoholic solutions of iodine green; (b) \k' ,.j Crystals of some of the common reagents which not infrequently sepa- rate on the shde and may be mistaken for cell contents: A, isotropic crystals of chloral wnich occur m cubes about lo m in diameter or long needles about 50 m long; B, phloro- giucm which occurs m broad rectangular plates or ellipsoidal discs from 10 to 35 /^ in diam- eter which are doubly refracting with a play of colors; C, cubes of potassium iodide which are isotropic; D, crystals from potassium hydrate solution which separate in broad prisms ana branching chains that are doubly refracting and give marked color effects. alcoholic solutions of haematoxylin and safranin; (c) solutions of eosin and methylene blue; (d) solutions of fuchsin and methylene blue; (e) solutions of gentian violet and Bismarck brown. Mounting of Specimens. — Microscopic preparations or mounts are of two kinds: they may serve a temporary purpose MICROSCOPIC TECHNIQUE AND REAGENTS. 763 only or they may be prepared so as to serve for future study, the latter being known as permanent mounts. In taking up the study of a specimen it should first be mounted in water and examined ; then the water may be replaced by a weak aqueous solution of glycerin (5 to 10 per cent.) and the specimen examined again. After this preliminary examination other agents and reagents may be employed. Specimens mounted in glycerin will keep for several days and even months. Generally speaking, the only efifect which the glycerin has on the tissues or contents is that of swelling them, which is obviated, to a greater or less extent, however, if the glycerin is washed out after an exam- ination is made. In addition to the methods involving the use of glycerin, there are two ways of making permanent mounts, depending upon the employment either of Canada balsam or glycerin jelly as the mounting medium. The method involving the use of the latter is the simpler, and leaves the specimen in such a condition that a re-examination with reagents can be made if desirable. Glycerin- jelly mounts are made as follows : Specimens which have been previously treated ate transferred to glycerin and allowed to remain for several hours, the excess of glycerin removed, and the specimen transferred to a warm slide on which a drop of glycerin jelly ^ has been placed. The preparation is warmed slightly to remove air-bubbles, and a warm cover-glass applied, care being taken to prevent the formation of air-bubbles. Evap- oration of the glycerin jelly is prevented by the use of shellac cements, asphalt varnish or candlewax. The following method may be used for the preparation of Canada balsam mounts: The specimen is cleared, dehydrated by the use of alcohol and then placed in chloroform or benzol. Hie clearing of the specimen is materially assisted by placing it in oil of cloves or turpentine prior to mounting it. A drop of Canada balsam solution (i part of balsam to 3 parts of chloroform or * Kaiser's Glycerin Jelly.— Digest 7 Gm. of gelatin in 42 Gm. of water for two hours on a hot water-bath ; dissolve i Gm. of carbolic acid in 49 Gm. of glycerin; mix the two solutions; heat on a water-bath, with occasional stirring, for fifteen minutes, and finally filter through glass wool. The jelly is warmed slightly to hquefy it before using. 764 A TEXT-BOOK OF BOTANY. benzol) is placed on a slide and the specimen mounted. When nearly dry, scrape off the excess of balsam, clean the slide and cover-glass with chloroform or benzol, and ring with cement. The MiCRO-POLARiscoPE is a useful accessory in conjunction with the microscope. It is employed in the study of technical products, and is chiefly applicable in the examination of crystals, starch grains and cell-walls. A number of substances, owing to certain peculiarities of structure, are double-refracting or aniso- tropic, i.e., they polarize light. If the double refraction is strong enough these substances show a play of colors. Of these may be mentioned the raphides and the rosette aggregates of calcium oxalate, cane sugar, citric acid, benzoic acid, caffeine, salicin, aloin, phloroglucin, and the salts of berberine, strychnine, and atropine. The acicular crystals which separate in chloral preparations of gambir also show a play of colors. Among the substances which are anisotropic but give no chromatic effects are starch grains, inulin, mannit, the rhombohedra in catechu and the various types of cell-walls. All substances which form crystals belonging tO' the isometric system are isotropic or single-refracting, i.e., do not polarize light, as sodium chloride, the octahedra in gambir, potassium iodide and chloral. When glass, which is an isotropic compound, is heated and suddenly cooled it is changed into an anisotropic body. Micro- scopic glas3 beads formed by quickly cooling very thin pieces of glass show polarization effects similar to those of wheat starch grains. This has led to the supposition that the polarization effects produced by starch grains are due to tension rather than to a crystalline structure. But this point cannot be definitely settled until it has been determined whether any of the substances composing the layers of the starch grains are capable of crystal- lization. The Spectroscope in Microscopic Analytical Work. — To a limited extent at the present time, and yet very effectively by those who are competent to employ it. the Spectroscope is being employed in the examination of organic coloring substances. This method has the advantage that accurate results can be obtained with small quantities of material. With the proper instruments and with practice one may attain a skill equal to that attained in MICROSCOPIC TECHNIQUE AND REAGENTS. 765 qualitative and quantitative analytical work. The Spectroscope can be used in checking chemical methods and also employed frequently in the detection of mixtures, just as the microscope is used where qualitative chemical methods are not available. The Spectroscope is used not only in the examination of single color- ing principles, but where there are mixtures, and whether these are in solution, on fabrics, on paper, etc. So that for technical chemists, especially for those interested in dyeing and allied indus- tries, it has a very great value. There are several different types of spectroscopes : ( i ) the ordinary, in which the liquid is placed in a long glass cell between the source of light and the slit of the spectroscope; (2) a com- parison spectroscope, where an unknown liquid can be compared with that of a know^n ; (3) the micro-spectroscope, in which a spectroscope is attached to a microscope and the liquid is placed in small tubes. A characteristic spectrum is obtained only when the solution is of the proper dilution. The solutions must be prepared care- fully and interfering substances removed as much as possible. (Consult: '' Untersuchung und Nachweis organischer Farb- stoffe auf spektroskopischen Wege," by Jaroslav Formanek and Dr. Eugen Grandmougin, Second Edition. " Zur Biologic des Chlorophylls Laubfarbe und Himmelslicht \^ergilbung und Etiole- ment," by Ernst Stahl. " The Origin and Nature of Color in Plants," Kraemer, in Proc. Am. Phil. Soc, 1904, p. 259.) Dark Field Illumination and the Ultra-microscope. — The study of minute particles which are otherwise not visible under the microscope by direct illumination may be accomplished by a simple contrivance known as a reflecting condenser. The principle upon which this operates is similar to when a pencil of sunlight enters a more or less darkened room, causing the par- ticles of dust to become visible. In the same manner the invisible particles in a colloidal solution and the ordinarily structureless substances in an animal or vegetable cell are rendered visible by reason of the contrast between these particles and their dark sur- roundings. The apparatus consists essentially of two parts: (i) a parab- oloid condenser which has two reflecting surfaces so as to bring f766 A TEXT-BOOK OF BOTANY. the rays of light to a focus on the objective and against a dark background; and (2) a funnel stop objective. The latter is an ordinary immersion objective with the addition of a funnel stop back of the lenses so that the diffused rays only enter the eye to the exclusion of the direct rays. An ordinary microscope with a reflecting condenser and a funnel stop objective thus constitutes an ultra-microscope. The illumination is by means of an arc light. If a Welsbach lamp is used it is necessary to employ a bull's-eye lens to concentrate the light upon the mirror. The light is ordinarily reflected through the condenser from the plane mirror of the microscope. Cover-glasses of a standard thickness, 0.17 mm., should be used. The space between the top of the condenser and the microscopic slide containing the object must be filled with a layer of cedar oil in the same way as between the cover-glass and the objective. Time must be taken to perfectly center the condenser with refer- ence to the objective. (Consult: " Dunkelfeldbeleuchtung und Ultramikroskopie," by N. Gaidukov.) MICRO-ANALYSIS. The value of the microscope is well established in the examina- tion not only of the living plant but in the study of various techni- cal products. It is usual to give greater prominence to the ana- tomical or HISTOLOGICAL method of study, based largely upon the form of cells and the structure and composition of their walls. The study of cell contents, as starch grains, calcium oxalate, phyto-globulins, and other definite substances, is being utilized very largely in the examination of technical products and to some extent by students of botany. A number of books have been published dealing with the micro-chemistry or histo-chemistry of some of these substances. For the most part the study of microscopic crystals has been of a very general nature, in that statements are given regarding the general shape of the crystals or their aggregates and their behavior with certain test solutions. The time has come when the study of the crystalline substances found in plants requires, if any real progress is to be made in this direction, that the MICROSCOPIC TECHNIQUE AND REAGENTS. 767 CRYSTALLOGRAPHic METHOD of examination be utilized This method originated in the examination of thin sections of rocks and It has been possible by this study to identify the numerous rock-formmg mineral species. In those species which are mixed crystals, i.e., made up of isomorphous mixtures of two or more components, it has been possible to determine with some accuracy their composition simply by their optical properties, as for exam- FiG. 420, Codeine: x-shaped skeleton crystals from lo per cent, alcoholic solution. pie the feldspars. Furthermore, it has been possible to draw conclusions as to the ultimate composition of rocks and the conditions under which they were formed. The value and possibilities of the employment of the crvstal- lographic method in biological studies is w^ell exemplified in the recent work of Reichert and Brown, '' The Crystallography of the Hemoglobins." By special means individual crystals of the hemoglobins were obtained and by purely cr)'stallographic methods, including a study of the forms and optical pro|icrties of such crystals, the hemoglobins of the 200 species of animals ^68 A TEXT-BOOK OF BOTANY. studied were differentiated in a manner that could not have been accomplished by chemical analysis or other methods of procedure. A careful study of much that has been written, and especially of the illustrations that have been made, of micro-crystals in plants and drugs, shows that erroneous conclusions may be easily drawn from the general appearance of crystalline precipitates or aggregates of crystals that are formed. For instance, Vogl has Fig. 421. Cubebin: orthorhombic crystals from Prollius' solution, showing various types of twinning (a, b, c); d, amorphous material in the form of oily drops (under-cooled liquid); e, this amorphous material crystallizing in aggregates. shown that the sphero-crystals, found in the glandular hairs of Mentha piperita and considered by some to be menthol, are found in leaves of many of the Labiat^e. Again, very many sub- stances produce aggregate groups which closely resemble each other, as of citric acid, cocaine hydrochloride, etc. In regard to the value of the crystallographic method we quote the following paragraph from Brown {loc. cit.) : " When a chemical compound solidifies from fusion, solution or vapor under conditions which are favorable to the development of MICROSCOPIC TECHNIQUE AND REAGENTS. 769 individuals, its particles tend to arrange themselves in regular order, so that a definite structure is produced. The external form of the individuals is also regular, heing hounded ])v i)lanes in definite relation to each other so that polyliedral solids are produced which are called cryst.vls. The regular arrangement of the atoms among themselves, and of the molecules which Fig. 422. Strychnine sulphate: tetragonal crystals in polarized light, showing siile aspect. they build up, is so characteristic of substances of donnite com- position that the crystalline condition of dead matter is the normal condition. Differences in chemical constitution are accomj)anied by differences of physical structure, and the crystallographic test of differences of chemical constitution is recognized as the most delicate test of such dift'erences." 49 770 A TEXT-BOOK OF BOTANY. It is apparent that, apart from their solubiHty, color reactions, behavior towards reagents, etc., the substances with which we are dealing should be prepared in such a manner that isolated crystals are formed and not aggregates or groups. These isolated crystals can then be studied independently. The reason why Pig. 423. Hydrastine: large, nearly equi dimensional orthorhombic crystals from alcoholic solution. ^gg^^gates are formed is because the crystals are permitted to grow too rapidly on the slide. This is usually the case in the usual method of procedure in securing crystals, i.e., by adding a drop of a solution to the slide, and then allowing it to evaporate spontaneously, under ordinary conditions. If, on the other hand, the rate of evaporation is lessened so that there is a slowing down of the growth of the crystals, individuals may be obtained of MICROSCOPIC TECHNIQUE AND REAGExXTS. 771 almost any size desired. And it will be found that these isolated crystals may be quite as easily prepared as the aggre^^ates which seem so characteristic to the average student. Special nietliods. however, may be necessary to obtain such isolated crystals, hor instance, single crystals of menthol (Fig. 126) are obtained by Fig. 424. Piperine: monoclinic crystals, mostly on the clinopinacoid, showing the oblique terminations, obtained from hot alcoholic solution. means of sublimation rather than from solutions. Cumarin crystals are easily obtained by controlling the tcmi)craturc of the melted mass, etc. The interest in these crystalline substances is becoming greater as foods and drugs and technical products are subject to stand- ards of purity. Most of the crystalline constituents common to 772 A TEXT-BOOK OF BOTANY. plant products are usually said to be calcium oxalate. This sub- stance is insoluble in water, alcohol, and acetic acid, soluble in the mineral acids and occurs usually in definite crystals. These crystals are rather easily studied in Iris, Ouillaja, etc. (see page i86). They are found to crystallize either in the tetragonal or monoclinic systems, sphenoids of the latter being present in Belladonna (see pages 183-192). Some substances occur in a crystalline form even upon the commercial product, as vanillin upon vanilla pods and cumarin upon tonka seeds ; or crystals may be found in special cells, as piperine (Fig. 424) in Piper album a.nd Piper nigrum. In alco- holic material, particularly of the Compositae, characteristic sphero- crystals are found, as in inula (see pages 150-154). Sometimes similar sphero-crystals are observed upon soaking the drug of commerce in water and then adding alcohol, as in Scilla. Again, crystalline substances separate upon the addition of mineral acids, as when nitric acid or sulphuric acid is added to sections of Hydrastis (Fig. 95). Again, upon dissolving the product either in water, as with catechu, or in solutions of chloral, as with gambir, a crystalline residue remains. Finally, upon extracting the dried plant with suitable solvents, as Prollius' solution, and evaporating the solvent, characteristic crystals separate, as with coca, hydrastis, nux-vomica, cinchona, cola, guarana, etc. ; or distinct crystalline precipitates may be obtained upon the addition of special reagents, as palladous chloride to solutions containing cocaine hydrochloride (Fig. 97), or gold chloride to solutions containing caffeine (Fig. 96). Attention has already been directed to the fact (pages 173-176) that quite a number of plant principles are capable of being sublimed. For some time past, in the study of certain of the cryptogams, as bacteria, yeasts, and fungi, there has been a disposition to rely upon physiological rather than morphological characters, this being due not only to the fact that these are more constant and characteristic in these organisms, but also to the fact that distinct morphological characters are entirely wanting in some cases. While the necessity for this additional study in the higher plants is not so apparent on account of the presence of well-defined morphological characters, still the value of physiological marks MICROSCOPIC TECHNIQUE AND REAGENTS, y-ji as one of the bases of classification is coming to be recognizc(i. The best illustration of this is to be found in tlic mono,i;rapli of the genus Eucalyptus by Baker and Smith, in wliirli they have utilized the chemical properties and physical characters of the oils, coloring principles, tannins, etc., in establishing difTcr- ences of affinities or species. There is a growing tendency on tlie part of investigators to study micro-chemically some of tiie char- acteristic plant constituents, as alkaloids, etc. As a rule, how- ever, the descriptions are superficial and the identification is by means of color reactions. No real scientific progress will be made until the botanist employs the petrographical microscope and is fairly v^^ell grounded in the principles of physical and chemical crystallography. The work is by no means so simple as in ordinary microscopic work, but when the principles governing the optical study of crystals are mastered, the study will appeal to botanists not only as a fertile field for research but also as a subject of importance in both morphological and taxonomic work. The study of microscopic crystals is accomplished by means of the petrographical microscope. Brown (/or. at.) has stated succinctly the nature and use of this instrument : " The necessity of studying small crystals, . . , has re- sulted in the evolution of a form of microscope which is at once a goniometer, a polariscope, and an instrument for measuring optic axial angles — in short, for determining the physical crys- tallographic constants of small crystals. . . . The polari- scope portion of the petrographical microscope enables the ob- server to determine the position and relative value of the elasticity axes of crystals, to observe the position of the optic axes, and to determine their inclination to each other and to the elasticity axes. From these data the optical character of the crystal is determined. These optical reactions may be studied by this instrument with as much ease, and in general with as much accuracy, as with the larger and better graduated polariscope; and the data thus obtained are quite as accurate in most cases as those obtained by the use of the larger instruments. The use of the special eye-pieces arranged with artificial twins of calcite or quartz enables the observer to determine the extinction 774 A TEXT-BOOK OF BOTANY. angles of the crystals with as much accuracy as can be done with any form of polariscope. *' From such observations made with the aid of this form of microscope the following constants may be determined : *' (i) The plane angles of the crystals, in most cases the interfacial angles, giving the data from which the axial ratios are computed — in other words, the morphological constants of single crystals. " (2) The relation of the composite crystals or twins to each other, their angles, and the position of the twin plane, twin axis, composition plane, and other constants of the twin crystals. " (3) The pleochroism of the crystals, the character of the colors of the light vibrating parallel to the elasticity axes in the crystals. This is effected by the use of the single polarizing prism below the stage. By analyzing this light with the micro- spectroscope the differences of tint and color may be given quantitative values in wave lengths. " (4) The position and relative values of the light elasticity axes in the crystals, upon which depend the angles of extinction of the crystals, measured from certain crystallographic axes or planes or edges. In uniaxial crystals (tetragonal and hexagonal systems) there are two such elasticity axes — the ordinary ray des- ignated as (JO, and the extraordinary ray, designated as e. Either one of these mcCy be the axis of greater or less elasticity ; and according as the extraordinary ray is the axis of less elasticity or of greater elasticity the crystal is called optically positive or optically negative. In biaxial crystals (orthorhombic, mono- clinic and triclinic systems) there are three elasticity axes at right angles to each other, and these are designated as 3, the axis of greatest elasticity; B, the axis of mean elasticity; and C, the axis of least elasticity.^ " (5) The position and angle of inclination of the optic axes or lines of single refraction through the crystals. These always lie in the plane of the elasticity axes d and C and the angles between the optic axes are bisected by the axes fl and C. Accord- ^ Elasticity in the optical sense is the reciprocal of refractive index ; hence a, b, t, are the axes of least, mean and greatest refractive index. MICROSCOPIC TECHNIQUE AND REA(JEXTS. 775 ing as to whether C or a is the axis bisecting the acute angle, the ACUTE BISECTRIX, Bxa, the Crystal is called optically positive or optically negative. Thus if Bx,, = C, the optical character is POSITIVE. The apparent angle between the optic axes is deter- mined by means of an eye-piece micrometer in an observation of the interference figure, looking along the acute bisectrix of the optic axes, and this angle is designated as 2E. The character of the double refraction may be determined by this angle." It is not possible in this work even to attempt to treat of the principles underlying the study of physical crystallography. The study is one requiring special laboratory instruction. ( )f the excellent works which the student will find useful the followinf,^ may be mentioned : P. Groth : Physikalische Krystallographie, 4th Ed., 1905. Theodor Liebisch: Grundriss der Physikalischen Krystallographie, 1896. Henry A. Miers: Mineralogy, 1902. In this work will be found several excellent chapters dealing with the principles of the measurement of crystals and the study of their optical properties. RoSENBUSCH AND WuLFiNG I Mikroskopische Physiographie der Mineralen und Gesteine. P. Groth : An Introduction to Chemical Crystallography. Translated by Hugh Marshall, 1906. In the Zeitschrift fi'ir Krystallographie will be found refer- ences to the crystallographic studies which have been made upon some of the important plant constituents, but as these studies were mostly made upon relatively large crystals, which could be measured and examined by means of the goniometer, these observations must be interpreted and applied to crystals which are formed upon microscopic slides. A rather large number of substances have been examined and only a few of the more important are included at this time. While drawings might have been made to illustrate the form of crystals and optical orientations, it was deemed advisable to use some of the photo-micrographs made by the author. The four- color plate (Figs. 99, 100) is introduced to show the chromatic eflfects observed by using crossed nicols. The plate illustrates salicin and cocaine hydrochloride and is a nearly exact reproduc- tion of the eflfects obtained with the micro-polariscopc. the electros y^e A TEXT-BOOK OF BOTANY. having been made from Lumiere autochrome plates, using direct sunlight. The method of obtaining the crystals was rather simple. The solvents used were distilled water, alcohol, ether, chloroform and a mixture of chloroform and alcohol. To a weighed amount of the substance was added a sufficient quantity of solvent to give a saturated solution. A drop of this was added to a slide which was covered either with a bell-jar or the cover of a Petri dish. If the crystals formed too rapidly, giving rise to crystal aggregates, more dilute solutions were made from the original solution until single crystals were obtained therefrom. In some instances, as with physostigmine salicylate, where the edges of the crystal are likely to be re-dissolved, the slides were finally dried in a desiccator over sulphuric acid. With caffeine gold chloride, the best crystals were obtained when the solutions were relatively weak. Again, it was found that after crystals were mounted in balsam, as cocaine hydrochloride, caffeine gold chlo- ride, etc., the isolated crystals grew considerably in size at' the expense of amorphous material. A rather unique instance of growth of large crystals was with menthol when the slide con- taining the silky aggregates was covered with another slide. Finally it should be stated that some patience aYid experience are necessary to obtain satisfactory crystals. WORKS OF REFERENCE. Principles of Microscopy. By A. E. Wright. Das Mikroskop. By Leopold Dippel. Anleitung zur Mikrochemischen Analyse. By H. Behrens. Die Botanische Mikrotechnik. By A. Zimmermann. Methods in Plant Histology. By Charles J. Chamberlain. Elements of Drawing. By John Ruskin. For Drawing of Crystals, consult " Crystallography and Practical Crystal Measurement," by A. E. H. Tutton. Physical Optics By Robert W. Wood. GLOSSARY. Abortive. Applied to organs that remain rudimentary, and do not attain perfection in form or function. Commonly applied to anthers and ovules (p. 391 ). Acaulescent. Stems so reduced as to make the plant seem stcmlcss, as in Aletris (p. 490). Accumbent. Cotyledons which are so folded that their edges are opposite the hypocotyl, as in the seeds of the water cress and other Cruci ferae. Achene (Achenium). A non-fleshy, or so-called dry. unilocular and one- seeded, indehiscent fruit, in which the pericarp is more or less firm and may or may not be united with the seed (p. 410). Achlamydeous. Flowers without a perianth. Applied to plants in which the flowers have neither calyx nor corolla, as the Willows. Acute. Applied to a sharp pointed summit, the edges of which form an angle which is less than a right angle. Specifically applied in describ- ing the summits of leaves and leaf-like organs. Adhesion. Same as adnation. See adnate. Adnate. The congenital union of diff'erent organs. Applied to stamens when the anther adheres longitudinally to the filament (p. 381) ; also to the union of different circles in the flower, as of stamens with corolla and the calyx tube with the ovary (p. 390). Adventive. Applied to introduced plants, which are only locally spon- taneous and not thoroughly naturalized. Aestivation. See Estivation. Akene. See achene. Aleurone. Applied to complex plant proteins consisting of a phyto- globulin. one or more globoids and other substances (p. 193). Alkaloid. An organic base occurring in certain plants, usually in com- bination with organic acids and exhibiting distinct chemical reactions and having marked physiological properties. Alternate. Following each the other in spiral succession. Usually applied to leaves (p. 363). Alternation of Generation. The alternation of two generations, as of gametophyte and sporophyte in the x'Xrchegoniates (p. 75). Alveolate. Honeycomb like; having angular depressions (alveoli) sepa- rated by thin walls. Applied to the receptacles of the flowers of the Compositae. Ament (Amentum). A spike consisting of unisexual, apetalous flowers, subtended by scales or bracts as the inflorescence in the Salicaccae (p. 508). Amphitropous (Half-anatropous). An ovule or seed having a partial raphe so that the hilum is lateral and intermediate between the chalaza and micropyle. Amplexicaul. Nearly surrounding or clasping the stem as the base of some leaves. AnaboHsm. Constructive metabolism, as in photosynthesis, whereby com- plex substances are built up from simpler ones (p. 252). Anastamosing. The branching and interlacing of the veins of leaves so as to form a well defined network. Anatropous. A form of ovule that is inverted on its stalk, the latter forming a lateral ridge or raphe extending the length of the seed and connecting the hilum and the chalaza (p. 379). 777 778 GLOSSARY. Ancipital. Applied to compressed stems having two opposite wing-like margins, as in Sisyrinchium. Androgynous. A monoecious plant having both staminate and pistillate flowers in the same inflorescence, as in some species of Carex. Anemophilous. Flowers in which pollination is affected by the wind, as the grasses and pines (p. 399). Annual. Of. for, or pertaining to a year, as plants which are of only one year's duration, or less (p. 330). Annular. Having thje form of a ring; applied to the ring-like thickenings of tracheae (p. 273), or to the ring-like layerings in the wood of trees indicating their growth (p. 433) Anther. The enlarged portion of the stamen which contains the pollen sacs (p. 379). Antheridium. A cell or group of cells which enclose the male gametes (sperms) or antherozoids, as in the Archegoniates (pp. 5 and 88). Antherozoid. The male gamete or sperm cell produced in the antheridium of Cryptogams (pp. 5 and 88). Anthotaxy ( Anthotaxis). The study of the arrangement of flowers on the stem (p. 393). Apetalous. Having no petals or corolla. Apiculate. Applied to the summit of leaves in which the midvein projects as a short and abrupt point or apiculus. Apocarpous. A gynsecium or aggregate of pistils in which the latter are distinct or separate. Also applied to fruits composed of separate carpels (p. 376). Apogamous. Without sexual reproduction, the plant perpetuating itself only by vegetative means. Apothecia. The disk-like or cup-shaped fruit bodies in Lichens and Dis- comycetes (p. 73). Archegonium. The female reproducing organ or egg in the Archegoniates and Gymnosperms (pp. 5, 88 and 109). Also known as oogonium. Archesporium. Any fertile tissue which gives rise to either sexual or asexual spores (pp. 79, 122 and 124). Arillode. An appendage or envelope of the seed-coat which originates at or near the micropyle (p. 427). Arillus (Aril). An appendaa;e or envelope of the seed-coat w^hich arises from the funiculus or placenta near the hilum (p. 427). Arthrospore. A vegetative cell which has passed into a resting state, becoming an asexual spore (p. 12). Ascocarp. A special sac containing asci (p. 47). Ascospore. A spore formed within an ascus (pp. 47 and 53). Ascus. A sporangium of a definite shape and size and which contains a definite number of spores. Typical of the Ascomycetes (p. 47). Assurgent. Applied to prostrate stems and leaves which become erect toward the summit. Attenuate. Becoming slender towards the summit ; slenderly tapering. Auricle. An ear-shaped or ear-like appendage. Auxospore. The name applied to the spores formed in the diatoms (p. 37). Awn. A bristle-shaped appendage, as the beard of wheat. Axil. The sinus formed between the upper surface of the leaf and the branch to which it is attached. Baccate. Fruits that are pulpy throughout and berry-like in structure. Barb. A hair or bristle-like appendage having retrorse teeth. Barbed. Furnished with barb-like hairs. Barbelate (Barbulate). Having finely barbed hairs. I GLOSSARY. 779 Basidium An enlarge,! terminal cell of the ,1 .1 Bast^Rt^Pfi?'""^ ''-S ^''^'^'^"™ spores (p '59;''"''- "^^"^^'' ^ypl'^. Bast (Bast fibers or Slereome) THp fih.V, ■ dated with the sieve tissue (p Ss') '^''^^ °««"'"R m the hark ass,,- L.ber and phloem, the former bein/mn^^™'"'?" ^""'"^^'1 ""I' bark, and the latter includinTbast fiberrsLrt'ld"- "'f'^ '" "'^■ panying cells. A distinction is asn sl^„,- " '", ""'' ""= ^"'"n- bast" and "hard bast." the former annlinT'Tu "'^'''' '"^'*«" "^■'i> to the cambium and he latterTo ht „ a^^ »" '' ' '"^"''- "' "'""' Berry A fleshy, indehiscent frui^ the "eeds of Xh ''*^""''<', ''','"' the sarcocarp (p. 4IO) The woM i!f " '^'' ^'''^ embedded in sense includes any small pulpy fruit 'i^,"= """' '" « horticultural technically classified as berr?es "^ p 41 n ) ' "'"■' "' "'^'<- » re not in which the xjleror woody por^rnlts^^^ ''"-'>- phloem (p. 341). ^ portion hcs between two layers of Biennial. Continuino- or lastincr for fw^ requiring two growiW seasons for th ^''^"' ?' ■ ^""''l ^^''''''^' '• ^■• (p. 330) ^ seasons for the completion of the life cycle •^.s,st^S££St£?-'-r^'^^M- ■■■' Bracteate. Having bracts Rrf .w'^/d F^i-nished with bractlets. "tVfu7t::lf- ^ ""'^ "- --ted on the flower-stalk or pedicel. But-EP- " -- "-1 as fl»,sr^ri.";^'— Bub ferous. Producing bulbs. '^' '■ Bulblet (Bulbel. Bulbil). A small aerial bulb growing in the axd- of Bu,b^s.";p-ta°imt^t-- ™e:i'&i^n'r: b[,l^ ^^-^<^^^'''' "^ pe. "R=^'^r:-iif rr — >■ --™ - --^- Burs.culate (Bursiform). Saccate or pouch-like ^'^^'°"^>P;^PP'"//^^3-. early. Applied to the sepals of the.Pap'.vera IS bent upon itself so as to bring the summit near the base (p. 379) ;8o GLOSSARY. Canaliculate. Furrowed or grooved. Applied to a deep longitudinal channel on the petiole of a leaf. Canescent. Hairs turning white or hoary; applied to plants having a gray pubescence. Capillary. Hair-like in structure and manner of growth. Capitate. Head-shaped, as applied to the stigma. Also applied to a terminal collection or cluster of flowers. Capsular. Pertaining to or in the nature of a capsule. Capsule. A dry, dehiscent fruit, consisting of two or more united carpels (p. 411). Carinal. Resembling a keel. Applied to the two lower connivent and more or less coherent petals of papilionaceous flowers. Carinate. Shaped like a keel, as the glumes of many grasses. Carpel. The sporophyll comprising the pistil (pp. 120 and 376). Carpophore. The prolongation of the floral axis in the Umbelliferae which supports the two mericarps (p. 417). Caruncle. An outgrowth of the micropyle ; a protuberance in the region of the hilum of the seed as in Ricinus (p. 427). Caryopsis. An indehiscent, non-fleshy fruit, possessing a thin pericarp. which is closely adherent to the thin seed coat. Commonly called grain as corn and wheat (pp. 417 and 466). Casparyan Spots. The suberized portion in the radial walls of the endodermal cells (p. 310). Catabolism. The process in which there is a breaking down of complex compounds into simpler ones; destructive metabolism (p. 252). Catkin. Same as Ament. Caudate. Having a tail-like appendage. Caudex. The woody persistent stem base of a perennial herb. Caulescent. A plant having a manifest stem as seen above the ground. Cauline. Relating to the stem ; as cauline leaves. Cell. The unit structure of the plant ; sometimes erroneously applied to the locule of the ovary (p. 2). Chaff. Thin, dry scales ; applied in describing the receptacles of the flowers in the Compositae. Chalaza. The basal portion of the seed where the integuments are united with the nucellus (p. 127). Chromatophore. A specific term used in describing the chloroplastids in the Algae (p. 18). Also applied to the green and yellow plastids in higher plants (p. 136). Ciliate. Provided with cilia. Cilia. Minute hair-like processes usually formed in unicellular organisms and their spores as a result of the outgrowth of the ectoplasm. They are usually two or more in number, and vibrate rapidly, producing locomotion (p. 10). Cinereous. (Cineraceous). Having the color of wood-ashes; ash-gray. Circinate. Coiled from the summit toward the base, as the young fronds of ferns. Circumscissile. Transversely dehiscent, as in the fruits of Hyoscyamus and Eucalyptus (p. 413). Clavate. Club-shaped ; gradually tapering toward the base. Cleistogamous (Clistogamous). Applied to flowers, which remain in the bud condition, but are pollinated from their own anthers producing seed. The violets, in addition to their conspicuous flowers in the spring, produce later inconspicuous cleistogamous flowers which are more fruitful than the spring blossoms. GLOSSARY. 781 Cleft, Applied to the division in a leaf or leaf-like organ, which extends about halfway to the midvein ; the sinus between the lobes being very narrow or acute. Coalescence. Same as Cohesion. Goenocytic. Like a syphon. Applied to plants in which their lilaments or cells are not divided by transverse walls (pp. 24 and 45). Cohesion. The union of parts or organs of the same kind (p. 390). Collateral. A tibrovascular bundle or mestome strand in which the leptome is developed on the outer face of the xylem or hadrome (p. 341). Coma. The tuft of hairs at the summit of some seeds, as Apocynum. Commissure. The separating wall of two carpels. Complete. Applied to a flower that possesses calyx, corolla, stamens and pistils (p. 298). Concentric. Applied to a fibrovascular bundle in which the leptome forms a continuous ring around the xylem or hadrome ; or vice-versa, the phloem may be surrounded by the hadrome, as in monocotyledonous stems (p. 342). Conduplicate. Folded together lengthwise. Applied to leaves which are so folded in the bud that the opposite halves of the lamina touch each other (p. 364). Confluent (Connate or Coherent). Applied to anther-lobes which are united at the summit of the filament and diverge from the point of attachment as in some of the Labiatae (p. 381). Conjugation. The method of reproduction by the fusion of the cell con- tents of two similar cells or gametes (p. 20). Connate. United; congenital. Applied to leaves which are united at their bases from their origin. Also applied to the union of anthers which are usually spoken of as being confluent (p. 356). Connective. That portion of the filament which serves to connect the anthers (p. 381). Connivent. Applied to anthers which are in close juxtaposition to each other, but not united (p. 712) as those of the violet. Convolute. Applied to buds in which the leaves are rolled around each other lengthwise, so that in transverse section they appear as forming a coil, as in the leaf-buds of the cherry (p. 364). Cordate. Inverted heart-shaped, with the summit sharp. Coriaceous. Of a leathery texture, as applied to leaves and the pericarp of fruits. Corm. A tuberous subterranean stem surrounded by scaly leaves, as in Crocus (p. 329). Corolla. The inner circle or spiral when the perianth consists of two distinct whorls (p. 382). Corona. A crown-like appendage at the summit of an organ. Applied to the pappus, corolla and stamens. Corymb. A convex or flat-topped flower cluster which resembles a raceme, excepting that all of the flowers are on the same level, due to the lengthening of the lower pedicels, as in the high or swamp blueberry. Crenate. A margin in which the teeth are rounded (p. 356). Crenulate. Diminutive of crenate. Cruciate. Having the form of a cross as the tetraspores of the red Algae; also applied to any 4-merous flower. Crustaceous. Hard and brittle in texture, as the thallus of certain Lichens (p. 73). Cryptocrystalline. Indistinctly or imperfectly crystalline. Sometimes ap- plied, but incorrectly, to sphenoidal micro-crystals (p. 187). 782 GLOSSARY. Crystal Sand (Kristallsand). Same as micro-crystals (p. 188). Crystalloid. Resemblins: a crystal, formerly applied to the phyto-globulin of the aleurone grain (p. 193). Cucullate. Having the shape or resembling a hood as the sepals of aconite (p. 3S3). The term galeate. however, is more commonly employed to describe a hood-like corolla. Culm. The jointed and usually hollow stem of grasses and sedges (p. 466). Cuneate. Wedge-shaped. Applied to the leaf or leaf-like organs. Cuspidate. An apiculate leaf in which the projecting midrib is sharp and rigid. Cyme. .A convex or flattened flower cluster, in which the flower at the summit of the primary axis, matures first (p. 395). Deciduous. Falling after a definite period of growth. Applied to leaves and leaf-like organs (p. 388). Also applied to trees the leaves of which are not evergreen. Decompound. Applied to compound leaves, the divisions of which are compounded a second time. Decumbent. Prostrate stems or branches having an ascending summit. Decurrent. Extendinu below the point of insertion, as the leaves of C7-0 talaria sagitlalis. Dehiscence. The opening of an organ, as a capsule, for the discharge of its seed (p. 411). Also applied to anthers for the discharge of pollen. and the sporangia of ferns at the time of discharge of the spores (p. 90). Deltoid. Triangular. The sides being nearly equal. Dentate. A margin having tooth-like divisions (p. 356). Denticulate. Diminutive of dentate. Depressed. Sunk below the margin. Dichotomous. Two-parted ; divided into pairs, as the forking thallus of Chondrus (p. 33). Didynamous. Applied to flowers of the Labiatse having two sets of stamens of unequal length (p. 381). Digitate. Having deep, tinger-like. radiating divisions. Dimorphous. Existing in two forms as the flowers of the partridge berr\ (p. 391). ^ DicEcious. Applied to plants in which the staminate and pistillate flowers are borne on separate individuals, as the Salicaceae (p. 50!^). Discoid. A head composed only of tubular flowers, as in some of the Compositse (p. 711 ). Disk (Disc). An enlargement of the torus situated at the base of or around the pistil and usually secreting nectar (pp. 120 and 402). Also applied to the central portion of the headsi of the Compositse which bear the tubular flowers. Dissepiment. The walls between the locules of a syncarpous gvnaecium (p. 378). Dorsal Pneumatic Tissue. The loose mesophyll of the leaf (p. 366). Dorsi ventral. Having unlike lower (dorsal) and upper (ventral) sur- faces (p. 366). Drupe. A fleshy, indehiscent fruit, having a more or less succulent sarcocarp and hard endocarp (p. 418). Driizen. A secreting or glandular cell. Driizenzotten. Same as glandular hairs (p. 222). Duct (Trachea or Vessel). A conducting cell of the hadrome or xvlem .(p. 273). F.chinate. Beset with sharp elevations like prickles or spines (p. 354). Egg or Egg Cell. The female gamete (pp. 5 and 124). GLOSSARY. 783 Emarginate. Having a shallow notch at the summit; applied- to leaves and petals (p. 355). Embryo. The young plantlet, arrested in its growth, which dt-veiops in the seeds of spermophytes (pp. 121 and 426). Endocarp. The inner layer of the pericarp (p. 410). Endodermis. The layer of cells, surrounding the stele in the primary structure, of roots and stems (p. 310). Endosmosis. The passage of a liquid or the cell-sap into the cell throu^li the wall (p. 251). Endosperm. The nutritive tissues formed in the embryo sac and always present in so-called albuminous seeds (pp. 126 and 425). Also applied to the prothallus of the female gametophyte of Gymnosperms. Ensiform. Sword-shaped, as the leaves of Iris. Entire. A margin without teeth, division or lobes. Entomophilous. Pollination through the visits of insects. Ephemeral. Existing for only a day or less. Epicarp. The outer layer of the fruit wall (p. 410). Epicotyl. The axis of the embryo above the cotyledons (p. 426). Epigynous. A flower in which the petals and stamens adhere to the ovary and appear to arise from the summit as in clove (pp. 120 and 389). The ovary of such a flower is said to be inferior. Epiphyte. A chlorophyllous plant which grows on another plant, as an orchid. Also called air plant. Equitant. Applied to distichous leaves whose conduplicate bases suc- cessively overlap, as in the Iris. Excurrent. Usually applied to the trees, as the spruce, in which the main axis or trunk continues without branching, giving the tree a pyramidal shape. Also -applied to apiculate and cuspidate leaves in \shich the midrib projects beyond the summit of the leaf. Exogenous. Applied to woody plants that produce a cambium rint;. thus adding annual layers of growth. Typical of dicotyledons. Exosmosis. The passage outward of the cell-sap from within a cell ^P- 251). Exospores (Conidia). Spores which arise on special hyphse (p. 41). Also sometimes applied to the outer layer of a spore or to the dried protoplasmic substance adhering to a spore. Exserted. Applied to stamens which project beyond the corolla. Extrorse. Applied to anthers which together vvith their lilaments are directed toward the perianth (p. 380). Farinaceous. Containing starch. Applied to seeds, roots and rhizomes ; which on fracture are starchy. Fascicle. A dense cluster. Fastigiate. Applied to branches which are nearly erect and close together. Ferruginous (Ferrugineous). Light reddish-brown. Fertile. Capable of producing seeds or spores. Fertilization. Fecundation in plants (p. 397). Also applied to the pro- cess of rendering land fertile, or productive. Fibrovascular Bundle. All of the tissues comprised in the xylem and phloem (p. 341). Filament. The support or stalk of an anther (pp. 379 and 404). Filamentous (Filiform). Thread-like. Fimbriate. Fringed with hairs, filiform processes or laciniations. as the petals of the carnation. Flaccid. Without tnrmness. Flexuous. Zigzag; curved or bent alternately in opposite directions, as the rachis of the strobile of the hop (p. 515). Floccose. A surface having tufts of wool-like hairs. 784 GLOSSARY FoHaceous. Resembling a leaf. Foliate. Having separate leaves. Foliose. Bearing numerous leaves, leaflets or leaf-like appendages. Follicle. A dry. dehiscent fruit consisting of one or more separate carpels, as star-anise (p. 419). Free. Separate from other organs. Frond. Applied to fern leaves and sometimes to other leaf-like expan- sions. Frutescent. Having the appearance or the habit of a shrub. Fugacious. See ephemeral ; both words being used interchangeably. Fugitive. Introduced plants which are neither native nor naturalized but occur sporadically. Funiculus (Funicle). The stalk of an ovule (p. 379). Fusiform. Spindle-shaped; applied to roots shaped like the radish, which taper at both ends, but also applied to fleshy roots like the carrot which taper more gradually in the lower portion. Galeate. Helmet-shaped. Used in the same sense as cucullate, the word galeate, however, being more commonly employed. Gamete. A conjugating cell which unites with another cell to form a sexual spore (p. 5). Gametoyphyte. The sexual generation in the Archegoniates (p. 75). Gamopetalous. A corolla in which the petals are more or less united (p. 385). Gamosepalous. A calyx in which there is a coalescence or union of its divisions or sepals (p. 385). Gemma. A bud-like propagative organ. Applied to the soredia of Lichens (p. 7^)- Gibbous. Having a rounded protuberance at the side or base; applied to the ovary. Gills. The narrow, radiating plates on the underside of the pileus of mushrooms (p. 59). Glabrate (Glabrous). A surface that is smooth and practically free of hairs or pubescence. Usually applied to the stem and its accompany- ing leaves. Gland. A secreting cell. Usually applied to tissues that secret mucilage, volatile oils, balsams and resins. Glandular. Having the function or character of a gland, as glandular hairs; also applied to a glandular cell or a glandular surface (pp. 626 and 354). Glaucous. Bluish-hoary, the appearance produced by a whitish-coat of wax on the surface of stems, leaves and fruits. Glomerule. An inflorescence condensed into the form of a head, as in the dog-wood. Glucoside. A chemical substance which on decomposition always yields glucose or an analagous compound. Glurae. The lowest floral leaves of a spikelet of the grasses and sedges (p. 426). Gonidium. The algal portion of a lichen (p. 71). Gymnospermous. Having naked seeds, or seeds not enclosed in a capsule (p. 111). Gynandrous. Having the stamens adnate to the pistil, as in the milkweeds. Gynobase. An enlargement of the receptacle of a flower supporting the ovary. Habit. The general appearance and manner of growth of a plant. Habitat. The area or region where a plant grows. A plant may be in- digenous, naturalized, localized or even in cultivation. GLOSSARY. ;83 Hastate. Halberd-shaped. Applied to leaves that are of a general tri- angular shape, but have at the base two lateral lobes which diverge at right angles from the principal axis, as in sheep sorrel (p. 524). Haustoria. The roots of parasitic plants which penetrate the tissues of their hosts (p. 306). Head. Applied to the inflorescence of the Composite which consists of clusters of nearly sessile flowers. Heterosporous. Plants which produce two kinds of asexual spores (p. 86). Hilum. The scar resulting when the ripe seed becomes detached from its stalk (p. 425). Also erroneously applied to the starch grain in describing the nucleus or point of origin of growth (p. 144). It was at one time supposed that the starch grain was attached to the cell at this point. Hirsute. Bristly hairy. Hyaline. Thin, transparent or translucent. Hydrophilous. Plants which are pollinated by the aid of water currents (p. 401). Hymenium. The spore-bearing surface of fungi as in mushrooms (p. 57). Hypha. The tilament or thread-like cell such as is formed by most fungi (p. 41). The mass or mat of interwoven hyphae constitutes the mycelium. Hypocotvl (Radicle). The axis of the embryo below the cotyledon (p. 426)'. Hypogynous. A flower in which the petals and stamens are situated on the receptacle beneath the ovary and free from it and the calyx ( pp. 120 and 389). The ovary of such a flower is said to be superior. Imbricate. A type of prefloration in which the sepals and petals interlap each other (p. 389). Imperfect. Applied to flowers in which the fertile elements consist of pistils or stamens only (p. 392). Incised. Applied to leaves having the margin cut into sharp lobes, as in the scarlet oak. Included. Applied to stamens w-hich do not project beyond the tube of the corolla. Incumbent. Cotyledons which are so folded that the dorsal surface of one is opposite to the hypocotyl, e.g. the seeds of mustard and many other Cruciferae. Indefinite. Usually applied to the parts of flowers, as of stamens, when there are more than ten, and not clearly in multiples of the ground plan of the flower. Indehiscent. Applied to fruits which do not open along the sutures to allow the discharge of seeds. Also applied to the anther. Indusium. The shield-like covering of the sori in ferns (p. 89). Inferior. Applied to an ovary that is adnate to the calyx. Inflorescence. The flower or flower cluster. The study of the arrange- ment of flowers on the axis is known as anthotaxy (p. 393). Infundibuliform. Funnel-shaped, as the corolla of the morning glory (p. 669). Innate. Borne on the summit of the axis. Applied to the usual type of anther (p. 381). Internode. That portion of the axis between two nodes (p. 320). Introrse. Anthers which are so attached to the filament that they face the axis of the flower (p. 379). Involucre. A spiral or circle of bracts subtending a single flower or a flower head (p. 395). 786 GLOSSARY. Involute. Applied to leaves in vernation, and to petals in estivation, i.e., when both margins are inrolled lengthwise on the ventral surface (p. 364). Irregular. Flowers in which the parts of the same circle show some irregularity in size or form, as in the Labiatae (p. 393). Isodiametric. Having the same diameter in all directions. Isosporous. A plant which produces but one kind of sporangium and one kind of asexual spores (p. 87). Keel (Carina). See Carinal. La'ciniate. Cut into narrow pointed lobes. Applied to leaves and leaf- like organs. Lamellae. Layers ; applied to the concentric markings or layers in starch grains (p. 144) and cell walls (p. 259). Lanate. Hairs that are matted. Lanceolate. Lance-shaped. Applied to narrow leaves which gradually taper toward the summit, as in Senna. Laticiferous. Cells or vessels containing latex (p. 239). Legume. An elongated, monocarpellary, usually dry fruit, in which de- hiscence takes place along both sutures (p. 419). Lenticels. Biconvex rifts on the outer surface of the trunk and older branches of trees, as the bark of cherry and birch. Lenticular. In the form of a double convex lens. Leptome (Sieve). The conducting cells in the phloem (p. 276). Also employed to include the accompanying cells and cambiform (p. 341). Libriform. Wood fibers; the strengthening cells of the xylem (p. 270). Ligulate. Applied to a narrow, flattened, gamopetalous corolla, as in the ray flowers of the Compositae (p. 311). Ligule. The membranous projection at the summit of the sheath of grasses and sedges. Lobed. A leaf margin in which the incisions extend about half way into the lamina, and the sinuses and the lobes are more or less rounded, as in the white oak (pp. 356 and 511). Lyrate. A pinnately-cleft leaf in which the lobes increase in size toward the summit, the latter being large and rounded, as in the lyre-leaved sage. Lysigenous. Applied to receptacles or reservoirs, formed by the disin- tegration of a number of cells. They usually contain mucilage, vola- tile oils or resins (p. 26). Macrosporangium ( Megasporangium). The sporangium in the higher heterosporous plants which produces only megaspores (p. 101). Macrospore (Megaspore). The spore which produces the female game- tophyte (p. 101). Macrosporophyll (Megasporophyll). A sporophyll which produces only megasporangia (p. 101). Marcescent. Withering, but more or less persistent, as the style and stigma. Membranous (Membranaceous). A thin, pliable and more or less trans- lucent structure. Mericarp. One of the two inferior achenes of the fruit of the Umbelli- ferae (p. 417). Meristem. Cells that possess the property of dividing and forming new tissues (pp. 253. 254 and 291). Mesocarp (Sarcocarp). The middle layer of the fruit wall (p. 410). Mestome Strand. A fibrovascular bundle without either wood or bast fibers (p. 341). Metabolism. All of the chemical changes involved in the activity or growth of the organism (p. 252). GLOSSARY. tRt Micropyle. The small opening of the seed coat, through which the radicle of the embryo protrudes on the germination of the seed Cp. 425). Microsporangium. The sporangium, in the higher heterospon.us plants. which produces only microspores (pp. 120 and 298). Microspore. The spore which i)roduces the male gametophyte (p. 2^)><). Microsporophvll. The sporophvll which produces (»nlv microsix.ranuii (uu 105 and 375). " " i ^ Ml- Monadelphous. Stamens united into a hollow tuhe hv their tilamenls, as in the Mallow Family (p. 382). IMonoecious. A plant having both staminate and i)istillatc flowers (.n the same individual, as in the chestnut (p. 392). Mucronate. Applied to a leaf in which the midril) is continued above the summit in the form of.a short narrow tip, as in Senna (p. 3.S6). Mycelium. The interwoven hyphae of the fungi (p. 41). Naked Flower. One in which the floral envelope is wanting, as in the Willow. Nectar. A peculiar sugar secreted by special glands in the flower. Nerxe. A vein in the leaf. Node. That portion of the stem from which the leaves arise (p. 320). Nucellus. The portion of the ovule surrounding the embryo-sac (p. 124). Nut. An achene-like fruit, the pericarp of which is more or less hard, as the chestnut (p. 420). Nutlet. The small achene-like fruit characteristic of the Labiatsc (p. 420). Ocreate. Applied to the fringed and clasping stipules of the Polvgonums (p. 357). Orthotropous (x\tropous). Applied to a straight ovule, having the fora- men at the summit and the stalk at the base (p. 379). Pale (Palea or Palet). The bract or fore leaf, which encloses the lodi- cules and the individual flowers of the grasses (p. 466). Palmate. Resembling an open hand with the fingers extended, as the leaves of the Castor oil plant (p. 355). Panicle. A branched or compound raceme (p. 396). Papillose (Papillate). Covered with papillse. or short, conical hairs having rounded summits, as the petals of Primula (p. 407). Pappus. The modified calyx in the Compositae. consisting of either bristles. awns or teeth at the summit of the achene. Parasitic. A plant which depends upon another plant or an animal for its sustenance (p. 40). Parietal. Applied to the placentae, when they extend from the central axis to the walls of the carpel, carrying the ovules or seeds with them, as in the watermelon. Parted. Deeply cleft, the divisions extending near to the midrib or base of the leaf. Pectinate. Having teeth like a comb. Pedicel. The stalk or support ot a single flower (p. 393). Peduncle. A stalk supporting a cluster of flowers ; also applied to the stalk of a single flower. Peltate. Having the petiole inserted at or near the centre of the dorsal surface of an orbicular lamina, as in the leaves of the nasturtium. Perennial. Applied to plants that persist for more than two years. Perfect. Applied to flowers having stamens and pistils that arc capable of fecundation. Perianth (Perigone). Applied to the floral envelopes, wdien the two circles, are alike in color and form, as in the Faster Lily. Pericarp. The ripened ovary or fruit wall (p. 410). Pericycle ( Pericambium). The stratum of cells beneath the endodermis (p. 312). ;88 GLOSSARY. Periderm. The outer layers of the trunk and older branches, which are formed from the phellogen or cork cambium (p. 291). Perigynous. Applied to a flower when the stamens are adnate with the tube of the perianth, as in the cherry (p. 389). Peristome. The margin of teeth-like cells at the summit of certain moss capsules (p. 79). Petiole. The stalk of a leaf. Petiolule. The stalk of a leaflet. Phelloderm. The thin-walled parenchyma cells formed by the cork cam- bium (p. 291 ). Phellogen. The meristem which forms cork and the phelloderm (p. 291). Phlcem. The leptone. stcreome and accompanying cells of a fibrovascular bundle (pp. 312 and 341). Photosynthesis. The process by which the chloroplastids, aided by light, manufacture starch and glucose from carbon dioxide and water (pp. 137 and 157). Pileus. The cap of mushrooms (p. 57). Pinnae. The primary divisions of a compound leaf or frond of a fern. Pinnatifid. A leaf in which the divisions extend near to the midrib, the lobes being narrow and acute. Pistil. The structure consisting of^ one or more megasporophylls in the spermophytes, and made up of the stigma, style and the ovary, en- closing the ovules. Pistillate. A flower provided with megasporophylls and lacking the microsporophylls, as the pistillate flowers of the oak. Placenta. That portion of the ovary which extends into the loculi from the united margins of the carpels and bears the ovules (p. 377). Plumule. The rudimentary bud at the summit of the epicotyl of the embryo, as tonka seed. Pollination. The transferral of the pollen from the anther to the stigma (p. 397). Pollinium (Pollinia). An agglutinated mass of pollen grains as in the milkweed flowers. Polypetalous. A flower in which the petals are separate ; applied to the Choripetalse or Archichlamydeae (p. 504). Pome. An indehiscent, half-inferior fruit consisting of the fleshy torus, as in the apple (p. 420). Pore. An unthickened portion of a cell wall (pp. 263 and 275). Procumbent. Prostrate; as the stem of the trailing arbutus. Prothallium (Prothallus). The gametophyte of the ferns (p. 88). Protonema. The prothallus of the mosses (p. 78). Puberulent. Covered with fine, very short hairs. Pubescent. Hairy; frequently used in a general way to denote diverse types of hairiness. Punctate. Applied to translucent dots caused by the presence of oil reservoirs within the tissues, as in the leaves of pilocarpus. Putamen. The hard and stone-like endocarp of the cherry and peach. Pyriform. Pear-shaped. Raceme. A simple inflorescence of the indeterminate type, in which the flowers are alternately arranged on the main axis as in the lily-of- the-valley (p. 394). Rachis (Rhachis). The axis of a raceme or spike of flowers; also ap- plied to the stalk bearing the leaflets of a pinnately compound leaf. Radiate. Applied to the inflorescence of the Compositae, in which the heads consist of both tubular and ray flowers, as in the sunflower. Radicle (Caulicle). A rootlet, or specifically the hypocotyl of the embryo in the seed. GLOSSARY. 789 Raphe (Rhaphe). The adnate stalk connecting the hilum and chalaza in an anatropous seed. Ray. A ligulate flower in the radiate head of the Compositae (pp 395 and 711). Receptacle. The summit of the pedicel which hears the organs oi the flower. Also applied to the summit of the peduncle, which bears a collection of flowers, as in the Compositae. Regular. A flower in which all the parts of the same circle are alike in size and shape, as in the rose. Reniform. Having the shape or form of the human kidney. Repand. Applied to a leaf margin which is somewhat wavy or undulate (sinuate), as in witchhazel. Reticulate. Having veins which ramify and branch in such a way as to form a network. Retrorse. Directed backward or downward ; applied to anthers. Retuse, Applied to the summit of an obtuse leaf having a broad and very shallow sinus. Revolute. Applied to a leaf-bud in which the margins of the leaves are enrolled lengthwise on the lower surface, as in fern fronds. Rhizome (Rootstock). A more or less fleshy underground stem (p 325), Ringent. A bilabiate corolla with the throat widely open, as in the sage. Rotate (Wheel-shaped). A corolla having a short tube and an outspread- ing limb, as in potato blossoms. Rugose. Rough and wrinkled ; applied to the upper surface of a leaf in which the reticulate venation is very pronounced. Runner (Stolon). A prostrate stem that produces roots at the nodes, forming new plants, as the strawberry. Saccate (Calcarate). A petal having a spur or sac, as in the violets (p. 388). Sagittate (Sagittal). Resembling the shape of an arrow or arrow-head; applied to leaves in which the upper portion is lanceolate and the lower is lobed, the lobes being directed downwards, as in Sagittaria. Samara. An achene-like fruit provided v^^ith a wing-like appendage, as the maple (p. 420). Saprophyte. A plant which derives its sustenance from decaying animal or vegetable matter, as the Indian pipe (p. 645), and many of the fungi (p. 40). Scabrous (Scabrate or Scabious). Roughened with scales, as a leaf sur- face. Scalariform. Applied to the ladder-like thickenings of trachese, being especially characteristic of the ferns. Scape. An inflorescence arising from a plant having radicle leaves, as the hyacinth. Scarious. A thin, dry, membranous bract, as in the involucre of some of the Compositae. Schizogenous (Schizogenic). Applied to cavities or reservoirs which are of intercellular origin. They usually contain volatile oils, resins and mucilage (p. 226). Schizo-lysigenous. Applied to cavities or receptacles within the plant which at first arise in a schizogenous manner, but later beci>me larger owing to the breaking down of the surrounding cells (p. 226). Sclereids. Sclerotic cells or stone cells (p. 267). Sclerotium. A hard, compact mass of resting hyphae (p. 52). Secund. Arranged on one side only; unilateral, as the flowers of the lily-of-the-valley. Segment. One of the divisions of a gamosepalous calyx or a gamopetalous corolla; also applied to leaves. 790 GLOSSARY. Sepal. One of the floral leaves of the calyx. Septate. Divided into compartments, as the wall of the ovary ; also applied to fruits, as the orange. Septicidal. Applied to capsules or pods in which dehiscence takes place along the sutures or dissepiments (p. 411). Septifragal. Applied to capsules in which the wall of the fruit or carpels separate from the dissepiments. Sericeous. Applied to a leaf surface when the hairs are extended in one direction giving the leaf a silky or satiny appearance (p. 54). Serrate. A leaf margin in which the teeth are directed toward the sum- mit, as in long Buchu. Sessile. Having no stalk or appreciable support ; applied to leaves, flowers and stigmas. Setaceous. Provided with stout hairs or bristles. Silicle. A broad silique-like fruit, as in the shepherd's purse, Silique. A narrow, elongated, 2-valved, dehiscent capsule, as in the mustard. Sinuate. Applied to the margin of a leaf which is strongly undulate, as in witchhazel. Sinus. The angle between two lobes of a leaf. Sorosis. A fleshy, multiple fruit, as in mulberry (p. 420). Sorus. An aggregate of sporangia in the ferns (p. 89). Spadix. A spike in which the axis is more or less fleshy. The spike is usually surrounded by a large bract (spathe), as in the Jack-in- the-Pulpit. Spathe. The conspicuous bract subtending or surrounding a spadix, as in the calla-lily. Spatulate. Applied to leaves and leaf-like organs, which are long and narrow, attenuated at the base and rounded at the summit. Spawn. The mycelium of fungi admixed with earth. In this form it is usually sold for propagation or cultivation, as the spawn of Agari- cus cam'pestris (p. 59). Spermatozoids. The sperm cells of antheridia (p. 5). Spermoderm. A term commonly employed by German writers to indicate the seed coat or the layers developed from the integuments of the ovule. These writers frequently use the word testa as equivalent to the spermoderm, not distinguishing it from the tegmen. Spicate. Applied to an inflorescence having the flowers arranged in spikes, as in the common plantain. Spike. A simple, elongated inflorescence, composed of sessile flowers (p. 394). Spinose (Spinous). Having hairs that are sharp and pointed (p. 354). Sporophvll. A leaf or leaf-like spore-bearing organ (pp. 104, 120 and 375)'. Sporophyte. The asexual generation in the Archegoniates (p. 75). Squarrose. Applied to involucral bracts which are rigid, divergent or recurved, as in Grindclia squarrosa. Stamen. The sporophyll in the spermophytes that bears the pollen grains (pp. 120, 298 and 379). Staminode (Staminodium). A sterile or aborted stamen (p. 391). Stele (Central cylinder). The tissues of the primary axis within the endodermis (p. 312). Stereids. A name sometimes applied to stone cells. Stereome. Bast fibers ; applied also to sclerenchymatous fibers which are not included in the fibrovascular bundle, as in the leaves of Gaultheria. Stigma. The summit of the pistil which receives the pollen (p. 378). GLOSSARY. 791 Stipe. The stalk or petiole, as in the fronds of ferns (p. 91 ) ; also ap- plied to the stalk of mushrooms (p. 57). Stipule. A pair of leaf-like structures at the base of some leaves ( i). .U8). Stolon. See Runner. Stoma (pi. Stomata). A physiological structure developed from the epidermal cells and consisting of two guard cells separated by an opening. The term is incorrectly applied, by authors, solely to the pore or opening between the guard cells. Stones cells (Sclerotic cells). A parenchymatous type of cell, having thick, lignified walls (p. 267). Strigose (Strigous). Hairs that are straight and sharp pointed or bristle- like; applied to stems and leaves. Strobile (Strobilus). A cone-like fruit, consisting of bracts and their achenes. as in the hop (p. 515). Distinguished from the pine cone which contains a pair of seeds at the base of the open scales. Strophiole. A small aril-like appendage, developed at or near the hilum of certain seeds, as in Sanguinaria. Style. The neck-like portion of the pistil subtending the stigma (p 37S). Stylopodium. A disk-like development at the base of the style in the fruits of the Umbelli ferae. Subulate. Applied to leaves which are narrow, more or less cylindrical and tapering to a sharp point, as of some of the junipers. Superior. An ovary which is free from the calyx (p. 78) ; also applied to fruits, the pericarp of which has been derived from the walls of the ovary only. Suture. The line of union of contiguous carpels (p. Z77). Symmetrical. Applied to flowers in which the parts of each circle are alike in form and number and in which the numerical plan has been perfectly carried out (p. 392). Sympetalous. Flowers in which the petals are united (pp. 385 and 643). Syncarpous. Applied to a pistil composed of two or more united carpels (p. 376). Terete. Slenderly cylindrical or slightly tapering, as the stems of bluets. Testa (Episperm). The outer layer of the seed coat (p. 425). Tegmen (Endopleura). The inner layer of the seed coat (p. 425). Tetradynamous. Applied to the stamens of the flowers of the Cruciferne. which are 6 in number and occur in 2 sets, one set consisting •)! 4 stamens having long filaments, and the other set of 2 stamens having short stalks (p. 381). Thallus. The vegetative organ. of the Thallophytes. It may consist of a single cell, a filament, or a group of cells which gives rise to a more or less flattened leaf-like structure (p. 6). Thyrse (Thyrsus). A compact panicle, the flowers -uf the primary axis being of the centripetal class, while the branches are of a centrifugal character, as ia the lilac. Tomentose (Tomentous). A surface densely covered with matted wooly hairs, as of the common mullein (p. 354). Torus. The summit of a stem, forming the receptacle of a flower and on which the floral organs are borne (p. 389). Tracheae (Vessels or Ducts). The conducting cells in the wood\ or xylem portion of the plant. They usually consist of a longitudinal rou of cells in w^hich the transverse walls are more or less absorbed (p. Z?^). Tracheids. The characteristic conducting cells comprising the wood or xylem of the Coniferae. The cells resemble in form libriform but usually are marked by bordered pores (p. 275). Trimorphous. Plants having 3 kinds of flowers, difl'ering in the relative lengths of the stamens and style, as in the spiked loose strife (p. 39^). 792" GLOSSARY. Truncate. Applied to leaves in which the summit appears as though the upper portion had been cut squarely off. as in the tulip poplar. Tuber. An enlarged, swollen portion of an underground stem, as the white potato (p. 326). Tubercles. The small nodules on the rootlets of the Leguminosae, and which are capable of assimilating atmospheric nitrogen. Tunicated. A bulb composed of a number of concentric fleshy scales, as in the onion. Turbinate. Shaped like an inverted cone ; top-shaped. Turgescent. Applied to cells that are filled with cell sap and distended beyond their normal size. Umbel. An inflorescence consisting of a number of flowers in which the pedicels are of equal length and arise from the summit of the same shoot, as in the Araliaceae and the milkweeds. The inflorescence of the Umbelliferae consists of compound umbels, in which the pedicel of each flower has a secondary umbel or umbellet (pp. 640-642). Uncinate. Applied to an achene having a hooked summit. Undulate. A leaf that has a repand or wavy margin, as in the witchhazel. Unguiculate. A petal that is contracted at the base into a claw or stalk. Uniseriate (Uniserial). Having the cells in a single row or series. Unisexual. Applied to plants in which the staminate and pistillate flowers are developed on different individuals, as in the willow and poplar. Utricle. An inferior achene-like fruit, having a thin and loose pericarp. as in Chenopodium (p. 420). Also applied to the perigynium. or inflated sac which encloses the ovary, of the flowers of Carex. Valvate. Applied to flower buds when the rudimentary sepals or petals touch each other at their margins (p. 389). Also applied to the dehiscence of capsules when the separation is at the margins of the carpels. Vernation (Prefoliation). The study of the folding of the leaves in buds. Verrucose (Verrucous). A surface covered with wart-like elevations, as in some of the gourds. Versatile. Applied to anthers which are attached, transversely or hori- zontally, to the summit of the filament, as the T-shaped stamens of the tiger lily. Verticillate. Applied to leaves or flowers which are arranged in whorls at the nodes. Villous. Applied to a surface having long, soft hairs and which are not matted or interwoven, Vittae. The oil tubes in the pericarp of the fruits of a large number of the Umbelliferae. Woolly. Covered with long, curly and more or less matted hairs. Often used in the same sense as tomentose, lanate or pubescent. Xylem. The tracheae and wood fibers of a fibrovascular bundle (pp. 312 ard 341). Zoospore. A motile asexual spore (p. 5). Zygoraorphic (Zygomorphous). Applied to flowers which can be bisected into similar halves in only one plane. They are also spoken of as dorsiventral flowers (p. 393). Zygospore (Zygote). A spore resulting from the union of two similar gametes or protoplasmic masses (pp. 5 and 19). INDEX. Abelmoschus, 434 Abies, up. 213, 434 Abnormal root structure stem structure. 344 Abortive. 391 ^^ Abrin, 198, 575 Abroma. 615 Abrotanum. 434 Abrus, 434, 575 Absmthe. 719 Absinthin. 719 Absinthium. 434. 7,^ Abuta. 539 Abutilon, 610. 6ri Acacia. 434. 567, 56 Acajou gum, 599 ^^^ Acanthacea-, 694 Acanthus family, 694 Accumbent, 426 Acer, 434, 602 Aceraceas, 602 Acetaldehyde. 234 Achene, 410 Achilleine. 172 Achras, 659 Achyranthes, 528 Acid abietic, 237 acetic, 234 . ^"lido-succinamic, 168 amino-acetic, 192 antirrhinic, 691 arabic, 222 arachidic, 212 behenic, 212 benzoic, 234 capric. 212 caproic, 212 caprylic, 212 carthamic. 720 cerasfc. 223 chaulmoogric. 274 chebulinic. 633 chromic, 756 cinnamic. 234, 572 formic, 234, 287 gallic, 599 gurjunic. 621 gynocardic, 623 hederic, 636 hydrocyanic, 198, 23% hypogjeic, 213 isovaleric, 234 japanic, 213 kinic, 655 Acid, lactic, zyn^ase. 245 lauric, 212 lichen. 72 Jignoceric, 212 linoleic, 213 lycopodic. 213 magenta. 182 methysticinic. 177 mynstic. 212 oleic. 213 palmitic. 212 Pectinic, 243 Phosphomolybdic, 164 phosphoric, 214 picric, 165, 756 Picnc-sulphuric, as fixing . agent, 756 ^ Pipitzahoic, 723 Protocatechuic, 204 rapic, 213 ^ resinolic, 237 ricinoleic, 213 salicyhc, 234 stearic, 212 succino-abietic, 2^7 sulphuric, in germination, tiglic, 213 yellow A. T.. 182 Aconite, 434, 53 Acomtum. tubers of' '3 2 8 Acorn-cups, tannin mf 206 Acorus, 434, 47^ Acre. 434 Acris, 434 Actsa, 434. 537 Actinomorphic, 397 Acubin, 696 Acuminate, 35s. 434 Acuminatus-a-um, 434 Acute. 354 ^ Acutifolius-a-um, 434 Adansonia. 612 Adder's tongue, 458 Adderwort, 438 Adhatoda, 696 Adhesion, 390 Adiantum. 88. 434 Adlumina, 550 Adnate. 381 Adnation. 390 Adonis. 434, 537 Advena. 434 Adventitious root. 301 ■^cidiospores, 69 ■^cidium, 69 Aegle. 434 Aenal root. 306 Aerobes. 252 Jj^-u'in. 169. 602 ■^scuhs, 602 tannin in. 206 ^stivahs. 434 African ammoniac. 639 Afzelia. 575 -^^ Agar-agar. 34 Agaric. 63. 64. 456 surgeon's. 65 Agaricaceje. 59 Agaricus. 434 campestris, 59 protein in. 200 muscarius. 155 Agave. 434. 435, constituents of. 493 fiber. 269 Agavose, 155 Agglutins. 198 Aggregatae. 707 Aglykone. 169. 170 Agnmonia. 434 Agropyron. 434, 453 Agrostemma. 17, ^^^ AUanthus. 434! sV' • ^'^ family, 585 Air-bubbles 752 method of detection. 7sa Air plants. 480 ^ Aizoacea, 528 Ajowan oil. 643 Ajuga. 434 Akene (see Achene). 410 A b.zzia. 575. 435 Albumins. ,94. i^s AJous-a-uni, 435 Alchemilla, 435 Alcoholase. 245 Alcohol, benzyl. 2ix camphyl. 233 ceryl. 214 cinnamic. 2^3 ^thyl. 2is melissyl. 214 methyl. 233, Aldehyde. 234 cinnamic. 544 salicylic, 564 Alder. 435. 5,^ buckthorn, 604 Aletns. 435. 4Q^ Aleuntes. 592 oil in, 213 7gj 794 INDEX. Aleurone, grains, 193 Alfa, 472 Alfalfa, 577 Algae, 7, 435 blue-green, 8 characteristic, 16 classes, 17 economic uses of, 40 of Red Sea. 8 of Yellowstone Park, 8 polluting water, 8 used as food, 40 used in medicine, 40 Alga-fungi, 42 Alisma, 466 Alismaceae, 466 Alizarin, 179. 703 preparation of, 704 Alkaloids, 159 chemical classification, 166 effect of climate on, 165 families yielding, 165 from cultivated and wild plants, 739 functions of, 172 microchemistry of, 160 origin of, 160 properties of, 163 reagents for, 163 Alkanet, 670 Alkanna, 670 Alkannin, 670 Allisin, 489 Allium, 435. 485. 489 vascular bundle of, 309 Allspice, 455 wild, 438 Almond, 43S emulsin, 243 oil in, 213 Alnus, 435. 510 glandular hairs in, 230 Aloe, 435 species of, 487 wood, 628 Alpinia, 494. 651 Alsine, 435. 53 1 Alstonia, 435 Alteration in forms of plants, 332 Alternation of generation, 78, 86 Althaea, 435. 609, 611 Alum root, 447. 556 Alyssum, 435 Amandin, 195 Amanita, 60-65 Amarantaceae, 528 Amaranth, 435 Amaranthus, 435. 528 Amarus-a-um, 435 Amaryllidaceae, 489 Amaryllis, 435. 492 Amaryllus family, 489 Amber. 119. 237 fossil, 119 seed, 611 Ambrosia, 435. 726 Ambrosiaceae, 712 Ambrosioides, 43S Amelanchier, 562 Aments, 508 American aloe, 434 copal, 574 kino, 569, 571 linden, 608 pennyroyal, 676 senna, 360 Americanus-a-um, 43s Amino-acid, 167 Ammanni, 435 Ammoniac, 639 African, 639 plant, 444 Ammoniacum, 435 Amomum, 435, 494 Amorpha, 435. 574 Amygdalin, 169, 170 Amygdalus, 435 Amylo-dextrin, 145 Amylo-pectinase, 242 Amylose, 144, 242 Amylurri, 435 Amyris, 585 Anabasis, 527 Anacardiaceae, 595 Anacardium, 435, 596, 599 Anacyclus, 435 714 Anaerobes, 252 Anagallis, 436 Anagyris, 575 Analysis, micro, 776 Anamirta, 436, 539 Ananas, 436, 480 Anatomical differences in leaves, 370 Anatomy, i Anatropous, 379 Andira, 436 Andrcecium, 381 Andromedotoxin, 648 Andropogon, 436, 467, 472 Anemone, 359. 436. 535. 537 Anemonol, 537 Anemonon, 537 Anemophilous flowers, 399 Anethol, 234, 643 Anethum, 436, 643 Angelica, 436 American, 643 European, 643 purple stemmed, 643 wild, 643 Angiosperms, 119 classification of, 463 development of, 120 economic importance of, 128 flowers of, 375 Angostura. 436. 443, 585 Angustifolius-a-um, 436 Anhalonidine, 625 Anhalonine, 625 Anhalonium, 625 Aniline blue, as staining agent, 757 Anime, 586 Anise, 436, 448, 639 Japanese star, 540 protein in, 200 star, 448 Anise-scented golden-rod, 722 Anisomeria, 528 Anisum, 436, 448, 639 Annatto, 621 Annual herbs, 330 rings, 343 Annular, 273 Annulus or ring, 61 Anr.uus-a-um, 436 Anogra, 436 Anona, 542 Anonaceae, 541 Anthelminticus-a-um, 436 Anthemis, 436, 713 Anther, 379 appendages of, 381 Antheridium, 5 Antherozoid, 5 ' Anthoceros, 83 Anthocyanin, 209, 3 10 origin of, 180 Anthophylli, 631 Anthotaxy, 393 Anthoxanthum, 436, 472 Anthracene, 170 derivatives, 179 Antidesma, 594 Antirrhinic acid, 691 Aparine, 436 Apeiba, 609 Apex of leaf, 354 Apiin, 169, 170 Apiol, 234, 643 Apiose, 169 Aplastic, 172 Apocarpous, 376 Apocynaceae, 574, 664 Apocynum, 386, 436, 664 fruit, 412 seed, 429 Apostasieae, 496 Apothecia, 73 Appendages of anther, 381 Apple. 457. 562 cedar, 115 earth, 440 may, 538 protein in, 199 rose, 632 rust, 115 star, 441, 659 sugar in, 156 Apricot. 562, 620 oil in, 213 protein in. 199 sugar in. 156 Aquaticus-a-um. 436 Aqu.fohacea;, 600 Aquifolium, 436 Aquilaria. 628 AquiJegia. 536 ■rt-rabin, 222 Araceas, 475. 473 Arachis. 401. 575 Arachnoidiscus ^sc Aragallus. 574 ' Arales, 475 Aralia. 436. 636. 637 Arahacea, 636 Araroba. 436 tree. 462 Arbor, 460 vitas, 118 ^i^^,"t.n. X69. X70. X74. Arbutus, trailing. 644. 649 Archegoniates. 75 ^^ Archegonium. 75 Archichlamyde*, 504^ Arctium, 436, 715, -]_ XTe!^''^'' '^^' 436. Areca. 436. 473 Arecaidine, 474 Arecaine, 474 Arecoline, 473 Arethusa, 502 Argania. 659 Argemone, 436, 547 Arginin, 253 ■^rillode, 427 Arillus, 427 I'^'.TT'J^^' 477. 480 Anstolochia. 436. 519, 5^1 Anstolochiales. 519 Anstotelia. 609 Arnica. 437. 7 is pollen of. 404 Arnotta, 621 Aromaticus-a-um. 437 Aros. 437 '437 Arrow-head. 466 Arrow root, 462 Maranta, 496 soft-leaved, 706 starch, 496 Arrow wood. 705 mapJe-leaved. 705 soft-leaved. 706 Artemisia. 437. 719 hairs of, 285 Arteraisi«folius-a-um. 437 INDEX. Arthrospore. 12 Artichoke, ferment in 24a elobe. 726 44 Jerusalem, 725 ArUfical coloring of flowars. 795 Artocarpus.437.3,^ ^"^"ni. 437. 478 Arundinaceus-a-um. 437 Arvensis-e, 437 ^^' Asafoetida, 445. 53^, ^sagrsa. 437 ^^ Asarone. 520 AstT/''^'^^^'^- Asclepiadaccce. 574 66« Asclepias.437.667'.'668 Ascomycetes. 47 Ascophyllum, 30 Ascus, 47 Asexual generation. 298 spore, 298 Ash, 446 mountain, 562 prickly, 462 white, 661 wild mountain. 454 Asim.na. 437, 54/^4 Asparagine, 167, 25, 7,. Asparagus. 437. ,85 489' protein in, 199 ^ sugar in. 156 Aspen. 456 Aspergillus, 49 emulsin, 243 Asperula. 437 Aspidium, 437 Aspidosperma. 437, 667 ■fi-splenium. 437 Assimilation root, 306 shoot, 299 Aster. 712, 726 Astragalus, 437, 56^^ gum in. 218 ^ Athamanticus-a-um. 437 ^^0^307"^"°-" «- Atriplex. 437, 527 Atropa. 437, 683. 684 fruit, 412 Atropous, 379 Atropurpureus-a-um, 437 Attar of rose. 564 Aucuba, 643 Aucubin, 643 Aurantiamann, 585 Aurantium, 437 Auric chloride, 165 Australis-e, 437 Autumnalis-e, 437 Auxochrome, 179 Auxospores. 37 Avena, 437, 457 structure of, 423 Avenalin, 195 Avens. 446 Avocado, 455 A^-seed. 442 purple, 646 aaccaurea. 594 Waccharis. 437 ,3, Baccfer-a-um ;3'7' Bacillus. 14 ^^7 hay, 13 subtilis, 13 'XT'- '"^-y- of.. Bacteria, 12 aerobic, 12 anaerobic, 12 classes of. 13 sulphur. 14 Bacterium. 14 Balanophora. 519 Balanophorace*. sig Baaa.^^^^^^ ^alatium, 241 Ballota, 437 ^alm, 452 of Gilead, 508 sweet, 679 Balsam, 225 ^'dmm ■ '' "'°""^'"e me- uium, 757 gurjun. 621 Maiacaibo, 572 mounts. 763 of fir. 118 o( the gardens. 604 of Tolu, 572 ^ Oregon, 119 poplar, 508 Sindor, 621 tree, 461 Balsamifer-a-um, 438 Balsaminace*, 604 Balsams, 236 Balsamum, 438 Bambusa. 466 Banana, 490 protein in, 199 sugar in. 1,6 Baneberry. 43^. 337 Banskia, 518 Baobab, 612 Baptisia, 438, 567, 573. 57c Baptism. 169 ^'* Barbaloin. 169 Barbarea. 438 Barberry. 4,8 ^ family. 537 oarbiera. 575 Barium salts. 575 Bark. 317 Barley. 448 lecithin in. 214 protein in. 199 796 INDEX. Barley, starch in, 148 sugar in, 156 Barosma, 438, 583 Barringtonia, 629 Base of leaf, 356 Basidiomycetes, 56 Basil, sweet, 679 Bassia, 659 Bassorin, 223 Basswood, 609 Bastard cedar, 580 santal. 580 Bauhinia, 575 Bayberry, 212, 508 Bay oil, 632 rum, 632 Beale's carmine solution, 760 Bean, 576 buck, 452 garden, 576 Indian, 440 Japanese soy, 576 kidney, 455 lima, 199 pichury, 453 protein in, 199 Sacred, 453 sea, 575 Bearberry, 436, 461, 651 Beard grass, 436 Bearwort, 452 Beauty, meadow, 634 Bebeeru, 453. 546 Bedstraw, 446, 697, 704 yellow, 704 Beeberine, 546 Beech, 44s, 510 American, 512 drops, 696 false, 644 nut, protein in, 199 purple, 178 red, 512 Beer manufacture, 515 Beet, 438, 527 garden, protein in, 199 sugar in, 156 sugar, 527 proteins in, 199 sugar in, 156 Beggiatoa. 14 Begonia, 624 hairs in, 282 Begoniaceae, 624 Belladonna, 438, 683, 740 hairs of, 284 lily. 435 root, cross section of, 318 Bell-flower family, 710 Bellwort. 485 Benedictus-a-um, 438 Bengal quince, 434 Benne oil, 691 Benzaldehyde, 234 Benzoinum, 438, 660 Benzo-quinhydrone, 179 Benzoquinone, 179 Benz-pyrrol, 180 Berberidaceae, 537 Berberine, 162, 180 Berberis, 438, 537 Bergamia, 584 Bergamot, 679 oil, 584 wild. 679 Berry, 410 partridge, 452 BerthoUetia, 629 Beta, 438, 527 stomata on leaves, 367 Betel. 508 leaves, 506 nut, 436, 473 palm, 476 Betonica, 438 Betony, 438 Betula, 438, 510 cross-section of wood, 346 BetulaceEe, 510 Betulase, 243 Betulinus-a-um, 438 Bezoars, vegetable, 577 Bhang, 516 Bicollateral mestome strands, 341 Bicuculla, 550, 551 Bidens, 438 Biennial herb, 330 Biennis-e, 438 Bifacial leaves, 349, 366 Biflorus-a-um, 438 Bigardia oil, 584 Bignonia, 438 Bignoniaceae, 691 Bilabiate, 386 Bilberry, 654, 655 Bind weed, 442 Birch, 438, 510 family, 510 white, cross-section of wood, 346 Bird food, 696 Bird-lime, 518 Birthroot, 461 Birthwort, 436 family, 519 Bisectrix, 775 Bishop's cap, 452 Bismarck brown, as staining agent, 757 Bistorta, 438, 527 Bitter sweet, 444. 684 Bixa, 621 Bixaceae, 621 Bixin, 622 Blackberry, 458 bush, 563 low, 563 sand, 563 sugar in, 156 Black catechu, 569 haw, 462, 704 hellebore, 537 Bladder-wrack, 28 Blade, 348 Blakea, 634 Blazing star, 449 Blights, 44 Blinding tree. 592 Blood orange, 584 root, 458, 547 Blueberry, cultivation of 656 dwarf, 653 early sweet, 653 high bush, 655 low, 654 low-bush, 65s Blue flag, larger, 492 indigo, 574 Bluets, 448, 697 Bocconia, 550 Bcehmeria, 438, 517 fibers in, 269 Boerhavia. 528 hairs in, 282 Bogbean, 665 Bog plants, 480 Bogs, sphagnum, 84 Bohmer's hsemacoxylin so- lution, 760 Boletus, 61 Bombaceae, 554, 612 Bombax, 554, 612 Bondicine, 576 Boneset, 712 false, 449 Borage family, 670 Border, 386 Bork, 293 Borneo camphor, 620 Borneol, 233, 544, 676 Borraginaceae, 670 Boswellia, 587 hairs in, 282 Botrychium, 365, 438 Bottle, reagent, for sterile solutions, 757 Bougainvillea, 528 Bouncing bet, 530, 531 Bower, Virgin's, 441 Box tree family, 594 Boxwood, 439 Brabeium, 518 Brachycerus-a-um, 438 Bracts, 388, 393. 402 Bramble, 458 Branches, lateral, 312 Brandy, 607 Brasiliensis-e, 438 Brassica, 438, 552, 553 Brauneria, 438, 723, 724 oil canals in, 224 phytomelane in, 260 Brazilian copal, 5 74 INDEX. •97 Brazilin, 179. 180 Brazil-nut, 629 aleurone grains of, 194 Breadfruit, 437, 516 Bread. St. John's 576 Breadstone, 39 Breathing root, 306 Bridelia, 593 Brier, cat, 459 green, 459 Brotneliaceae, 480 Bromelin, 244 Broom, 443 green, 569 Scotch, 569 weed, 458 Broom-rape family, 696 Brosimum, 516 Brucamarine, 586 Brucea, 586 Bruguiera, 631 Brush, 472 Bryonia, 438, 709 sieve in, 276 tendril of, 323 Bryonidin, 709 Bryonin, 709 red, 709 white, 709 Bryophytes, 76 economic uses of, 84 Bubbles, air, 752 Buchania, 599 Buchu, 152, 438, 583 Buckbean, 665 Buckeye family, 602 Buckthorn, 445, 45? family, 604 Buckwheat, 445. 526, 527 family, 520 flowers, 400 protein in, 199 sugar in, 156 Bud, apical, 321 axillary, 321 scale, 120 scaly, 321 terminal, 321 Buds, 321 Buffalo berry, 628 Bugbane, 441 Bugle weed, 434, 451 Bulb, 327 Bulbils, 327 Bulblets, 327 Bunt, 461 Bur, 510 Burdock, 436, 449. 7I5. 7I7 Burning bush, 600 Bur-reed, 464 family, 463 Bursa, 438 pastoris, 439 Bursera, 587 Burseraceae, 586 Bursine, 554 Butcher's blocks, 560 Butneria, 439 Butter, cacao, 612 shea, 659 vegetable, 659 Butter-and-eggs, 691 Buttercup, 457. 537 Butter-fly weed, 667 Butternut, 509 Buttonbush, 440, 703, 704 Buttons, 473 mescal, 625 Button-snakeroot, 722 Buttonwood, 559 Butyrospermum, 659 Buxaceae, 594 Buxine, 594 Buxus. 439. 546, 594 Cabbage, 553 Cacao, 148, 211, 439. 460, 612 butter, 612 protein in, 199 red, 612 seeds, 612 starch in, 148 sugar in, 156 tree, 612 Cactaceae, 625 Cactus, 439. 621, 62s coach- whip, 621 family, 625 Cadinene, 233, 589, 642 Caducous, 388 Caesalpinia, 439, 576 coriaria, tannin in, 206 Caesalpinioideae, 567 Caflfeine, 162, 176, 600, 618, 700 Cajuputi. 439. 452 Calabar bean, 455 Calamint, 441 Calamites, 100 Calamus, 439. 474. 479 Calcarate, 388 Calcium carbonate, 200 oxalate, 183 phosphate, 186 Calendula. 387, 439. 7i8 hairs in. 288 pollen of, 40s Calisaya, 439 Calla, 439. 479 Calla-lily. 478 Callitris, 119 Calluna, 439 Callus, 277 Calophyllum, 439. 618. 619 inophyllum, 212 Caltha, 439 Caltrop family. 581 Calumba, 439. 539 American, 445 CalyptroRcn. 254 Calyx, 402 duration of. 388 Cambium. 314 intrafascicular. 341 ring. 341 Cambogia, 439 Camelina, 439 Campanulacea?, 708, 710 Campanulata;. 70H Campanulatc, 388 Campcchianus-a-uiii. 4 <'j Campcstris-c, 43'; Camphene, 676 Camphor, 439, 544, si''. ''Jto Borneo. 620 culture, 746 Japanese, 234 Laurus. 234 tree. 545 Campion. 451 Camptosorus, 439 Campylotropous, 379 Canada fleabane, 713 moonseed, 539 Canadensis-e, 439 Canaigre, 527 Canango, 542 Canarium, 586 Cancer root. 695, 696 Cane, 439. 445 Cane-sugar, 155, 156 Canella, 622 bark, 622 substitute, 622 Canellacea;, 622 Canna, 496 Cannabinus-a-um. 439 Cannabis, 439. 5i3 American. 741. 742. 744 fiber. 269 hairs of, 284 Cannaccce, 49A Cantaloupe, 710 sugar in, 156 Cantharellus, 58 Caoutchouc, 439. 5I3. 5i6. 592 threads, 240 Cape jasmme, 704 Caper, 579 spurge, 591 wild, 591 Capillaceus-a-um, 439 Capillus-Veneris, 439 Capitulum. 71 1 Caprifoliace£e, 704 Capsella. 438. 430. 554 ferment in. 244 Capsicum, 439. 687 protein in, 200 Capsule, 41 1 Caraipa. 618 Caramel, synthetic, 159 Carapa oil. 589 798 INDEX. Caraway, 440. 639 protein in, 200 Cariiamases, 244 Carbohydrates, origin of , 157 photosynthetic, IS7 Carbon dioxide assimilation, 299. 350 Carboniferous age, 99 Carbon-like substance, 258 Cardamom, 410. 435. 439. 444. 494 protein in, 200 starch in, 148 Cardinal flower, 710 Cardol, 596 Carduus, 451 Carex, 439, 47i. 472 Careya, 629 Carica, 440, 542, 624 ferment in, 244 Caricaceae, 624 Carices, 472 Carnation, 443. 53i Carnauba-palm, 214, 474 Carnauba-wax. 474 Carnivorous plants, 361 Caroba, 691 Carobine, 691 Carobone, 691 Carolianus-a-um, 440 Carolina pink, 661 Carolinensis, 440 Carota, 440 Carotin, 493. 636 Carpaine, 624 Carpel, 120, 374-376 Carpinus, 440, 510 Carpophore, 417 Carposid, 624 Carragheen, 31 Carrot, 440, 443 family, 636 protein in, I99 starch in, 148 sugar in, 156 Carthamic acid, 720 Carthamin, 720 Carthamus, 387, 719 pollen of, 40s Carum, 440, 639, 643 Caruncle, 427 Carvacrol, 234, 679 Carvi, 440 Carvone, 234 Carya. 333 cross-section of wood, 346 Caryophyllaceae, 531 Caryophyllene, 57i Caryophyllus, 440, 632 Caryopsis, 417, 466 Caryota, 476 Cascara, 440, 604 Cascarilla, 440, 592 Cascarillin, 592 Casearia, 623 Cashew, 435, 458, 596 Casparyan spots. 310 Cassia, 360, 440. 5^7. 575 purging. 567 species of, 567 Cassine. 600 Castanea, 440 cross-section of wood, 346 species of. 512 Castilloa. 241. 5i6 Castinin, I95 Castor bean, 457 aleurone grains in, 194 plant, 443. 59i Catabolism, 252 Catalases, 24s Catalpa, 440. 691 Catalpin. 691 Cataria, 440 Catawba grape, 606 Cat brier, 485 Catechin, 180 Catechu, 440 black, 569 Catha, 600 Cathartocarpus, 440 Cathine, 600 Catkin, 394 Cat mint, 680 Catnip, 440, 453. 680. 681 Cat-tail family, 463 Cauliflower, protein in, 199 sugar in, 156 Caulophylline, 538 Caulophyllum, 440, 537 Cavanillesia, 612 Cay-Cay butter, 586 Ceanothus, 440. 604 Cecidien, 334 Cedar, 460 apples, IIS bastard, 581 prickly, 454 red. IIS, 118 uses of, 11S-117 white, 118 wood oil, S89 Cedrela, S89 Cedron, 440, 459 seed. 440 Cedronin, 586 Cedrus, Ii8 Celandine, 441. 548. 5Si Celastraceae, 600 Celastrine, 600 Celastrus, 440, 600 Celery, protein in, 199 Celloidin, 749 Cells, 2 antipodal, 124 apical, 2S4 conducting, 272 contents, examination of, 246 Cells, contents reaction with microchemical reagents, 759 cork, 290, division, 3 epidermal, 277 forms of, 262 guard, 279 helping, 124 inclusion, 207 kinds of, 297 laticiferous, 239 protecting, 277 sclerenchyma. 266 sclerotic. 267 secretory, 226 stereomatic, 268 stone, 267 tapetal, 121, 404 Cellulases, 244 Cellulose, 2s6 walls, protective, 2S7 Cell-wall, reaction with mi- crochemical reagents, 759 stratification in. 2s8 striation in, 259 Celosia, S28 Centaurea, 440 Centifolius-a-um, 440 Centrifugal, development 262 Centripetal, development, 262 Centrospermae. 527 Centrospheres, I35 Century plant, 489 Cephaelis, 440, 699 Cephalanthin, 704 Cephalanthus, 440. 703. 704 Cephalaria, 708 Ceramium, 40 Cerasin, 223 Ceratonia, 440, 576 Cerealis-e, 440 Cereus, 625, 627 night-blooming, 625 Cetraria, 73. 440 Cevadilla, 458 Chakazzi c^pal, S74 Chamselirium, 440, 491 Chamomile, German, 71S Roman, 713 wild, 452 Chamomilla, 440 Champagne, 607 Chanterelle, 58 Characeee, 26 Charcoal, 508, 509 Charlock, 553 Chartreuse, 679 Chavicol, 632 Chebulinic acid, 633 Chekan, Eugenia, 441, 632 Chelerythrine, 550 Chelidonine, 550 INDEX. 799 Cheliodonium, 441, 548, 550, SSI Chelidoxanthin. 550 Chelone, 441, 691 Chemical stimuli, 248 Chenopodiaceae, 527 Chenopodiales, 527 Chenopodium. 441, 527 hairs in, 282 Cherry, 456 bark of, 294 choke, 561 cross-section of wood, 346 protein in, 199 sugar in. 156 wild, 561 black, 560 Chestnut, 511 American, 512 bark disease, 54 cross-section of wood , 346 horse, 206, 602 oak, tannin in, 206 protein in, 199 Spanish, 512 starch in, 148 sugar in, 156 tree, 440 wild, 518 Chests, tea, 625 Chewing gum, 659 Chew-stick, 447 Chickweed, 43S Chicory, 441, 716, 725 culture, 747 Chimaphila, 441, 455, 644 Chinese galls, 597 potatoes, 492 rice paper, 636 tallow tree, 594 Chinquapin. 512 starch in, 148 Chionanthin, 661 Chionanthus, 441, 661 Chirata, 441, 664 Chirayita, 441. 664 Chiretta, 460, 664 Chives, 485 Chloral, crystals, 762 Chloranthy, 391 Chlorenchyma, 366 Chlorococcum, 72 Chlorophora, 516 Chlorophyceae, 17, 20 • Chlorophyll, 138, 158 Chloroplastids, 137 Chloroplasts. 137 Chlorosis, 391 Chlor-zinc-iodide solution, 760 Choke cherry. 561 Chondrodendron, 441, 539 Chondrus, 31. 44 1 Choripetalae, 504 Choripetalous, 383 Chorisepalous, 383 Chorisia, 612 Chorisis, 390 Christmas holly, 600 Chromatin. 136 Chromatophore, 136 fixed oils in, 210 Chromene, 180 Chromic acid, 756 Chromogen. 179 Chromophores, 179 Chromoplastids, 137. 138 occurrence of, 181 Chromosomes. 136 Chrozophora, 593 Chrysanthemum, 441, 714, 718, 724, 726 Chrysarobinum, 441 Chrysophyllum, 441, 659 Chrysosplenium, 441, 556 Chymases, 244 Cicely, sweet, 643 Cichoriaceae, 71 1 Cichorium, 441, 716, 725 Cicuta, 441, 575, 642 Cigar boxes, 117. 589 Cimicifuga, 441, 532, 533 Cinchona, 441, 697 cultivated, 546, 690, 698 plantation, 698 species of, 699 substitute, 606, 620 Cineol containing oil, 544 Cinereus-a-um, 441 Cinnamic acid, 572 aldehyde, 544 Cinnamodendron, 622 Cinnamomum, 441. 543, 544, S45 Cinnamon cultivation, 545 cutting, 545 oil, 544 starch in, 148 Cinquefoil, 456 Circa^a, 441, 634 Circinate, 364 Circumcissile, 413 Circumnutation, 360 Cirrhiferous, 357 Cissampelos, 441 Cistus, hairs in, 282 Citral, 233. 234, 564. 583 Citron, 441, 584 Citronellol, 564, 579 Citrullus, 424, 441, 708, 710 Citrus, 441, 583, 584 Cladonia, 72, 74 Claptonia, 531 Claret, 607 Clavatus-a-um, 44I Clava-Herculis, 441 Clavaria, 58 Clavariaceae, 59 Claviceps, 441 Claviceps purpurea, 5a Claw, 385 Clearing agents. 755. 756 Cleavers. 446 Cleaverwort. 436 Cleft. 356 Cleistogamous, 391 Clematis, 441. 537 cork in, 293 Climbers, 324 Clinopodium, 441 Clitoria, 575 Clotbur, 462 Clove, 440, 441, 632 protein in, 200 starch in, 148 tree, 445 Clover, 567. 576 prairie, 449 sweet. 452 Club-like, 441 Clusia, 619, 620 Cnicin. 723 Cnicus. 441, 723 Coach-whip cactus. 621 Coal age. 99 deposits, T19 Coalescence. 390 Coca, 442, 580 family, 580 seedling. 745 Cocaine, 163, 170, 581 Cocci, 13 Coccos oil. 623 Cocculus. 442. 539 Coccus. 442. 516, 531. 606, 621. 627 lacca. 238 Cochineal insect. 627 Cochlearia. 442. 553 Cochlospermum. 223. 622 Cocillana. 516 Cocklebur. 462 Cock's-comb. 528 Cocoa (see Cacao) Brazilian, 603 Cocoa-nut. 212. 474 palm, 474 double. 427 fruit. 413 protein in. 109 Cocos. 474. 476 fruit. 413 Codeine crystals. 767 Coenocytic. ^4, 45 Coffta. 44J, 700 Coffee, 44J, 700 aroma, 700 caffeine in, 162 Kentucky. 447 picking. 702 protein in. 199 roasting. 700 substitutes. 611. 716 sugar in. 156 8oo INDEX. Coffee tree, S7S. 70i wild, 632, 707 Coffeol, 700 Cohesion. 390 Cohosh. 434 black, 532 blue. 440. 537 Cola. 614. 615 caffeine in. 162 family, 612 Colchicum. 442. 485 Cold frames, 731 Colic-root, 435. 485 , Coliguaya. 593 Collateral mestome strands, 341 Collenchyma, 265 Colletin, 606 Collinsonia, 442 Colloidal, 140 Colocynth, 708 fruit, 410, 424 seed. 424 Colocynthis, 442 Color in autumn leaves. 178 in lichens, 72 principles, chemistry, 179 substances, cell-sap, 176, 181 substances, distribution of, 181 Coloring of flowers, artificial, 182 Colors, cell-sap, 176 function of, 181 Coltsfoot. 387. 445. 461, 723 Colubrina, 606 Columbine, wild, 536 Columbo, 539 Combretaceae, 633 Combretum, 633 hairs in, 282 Comfrey, 460. 671 Commelina, 442, 480 Commelinaceae, 480 Commiphora, 442. 586 Common mossy stonecrop, 556 Communis-e, 442 Compass plant, 723 Complete flower, 298 Compositae, 711, 712 flowers of, 387 hairs in, 288 Compound leaves, 356 Comptonia, 509 Concentric mestome strands, 342 Conduplicate, 364 Condurango, 668 Cones, 375 Confluent, 381 Conglutin, 195 Conidia, 41 Conifera-um. 442 Coniferae, uses of. 117 Coniferin. 169, 170. 171. 489 Conium, 442, 638, 640 Conjugatae, 17 Conjunctive tissue, 313 Connate-perfoliate. 356 Connective, 122. 381 Conopholis, 695, 696 Consolodin, 673 Contortas. 660 Contraction of roots. 319 Contrayerva. 444 Convallamarin, 170, 442, 486 Convallaria. 487 Convolute, 364 Convolvulacese, 668 Convolvulus, 442, 669 Copaiba, 442, 57i. 574 substitute, 621 Copal. American, 574 Brazilian. 574 Chakazzi, 574 East Indian, 587 Inhambane. 574 resins, 574 Sierra Leone. 574 Zanzibar. 574 Copalchi, 592 Copalchin. 592 Copernicia. 474 cerifera, 214 Copper acetate solution. 761 treatment of water. 8 Coptis. 442 Coral root. 442 Corallorhiza. 442 Corchorus. 269. 609 Cordifolius-a-um. 443 Coriamyrtin. 595 Coriander, 442 protein in. 200 Coriandrum. 442, 637 Coriaraceae, 594 Coriaria, 594 Coriarious-a-um, 442 Cork cells, 290 development, 293 Corm, 329, 477 Corn, 467 Black Mexican, 178 cockle, 434. 446 seed, 426 Indian, 462 root-tip, 300 oil in, 213 protein in, 199 silk. 178 starch in, 148 sugar in, 156 Cornaceae, 643 Cornel, 442 Cornin, 643 Cornus,.442, 388. 643 Corolla. 382, 402 Corona. 623 Corpnilla. 442, 575 Cortex. 310 secondary, 313 Corydaline. 551 Corydalis. 209. 551 Corylus. 442, 510 Corymb. 394 Corymbihe. 702 Corynine. 702 Cotoneaster. 562 Cotton, 447 fiber, 269 protein in, 199 Sea Island, 610 seed, oil in, 213 oil. 611 Cotula, 442 Cotyledon. 299. 426 Couch-grass, 468 Coumarin. 472 in polypodium. 96 Couroupita. 629 Corillea. 581 Cowhage, 452, 576 Cranberry, 656 American, 655 European, 656 fruit, 417 small, 655 tree, 704 Cranesbill. 446 Crassulaceae. 556 Crataegus, 442. 565 Crateriform, 388 Cratoxylum, 619 Crawley root, 453 Cream nut, 630 Cream-of-tartar tree, 6i3 Crecopia, 516 Cremocarp, 417, 636 Crenate, 356 Crenulatus-a-um, 442 Creosote, 512 bush, 580 Cress, Indian, 579 Cretian origanum, 679 Crinum, 492 Crispus-a-um, 442 Croceine M. O. O., 182 Crocin, 493, 704 Crocus, 442, 493, 704 pollen of, 404. 40s stigma of, 405 Ciops. harvesting of. 738 Cross-pollination. 560 Cross-section, 749 Crotalaria. 442. 57s Crotin, 198 Croton. 443. 591-593 oil in, 213 Crowfoot, 457. 532 Crown-galls, 335 Crucifer-a-um, 443 Cruciferae. 55 1. 574 Cruciger-a-um. 443 Cryptogams, 5 vascular, 86 Crystal, 769 biaxial, 774 clusters, 185 codeine, 767 columnar, 183 fibers, 187 hexagonal, 774 hydrastine, 770 membrane, 189 micro, 187 microtechnic, 776 monoclinic, 183, 184, 774 of fixed oils, 211 of reagents, 762 orthorhombic, 183, 774 piperine, 771 sand, 188 solitary, 183 sphere, 192 strychnine crystals, 769 tetragonal, 183, 774 triclinic, 774 uniaxial, 774 Crystalline wax, 216 Crystallographic method of examination, 767 Crystalloidal, 140- Crystalloids, 193, 199 Cubeb, 443, 504 substitute, 541 Cubebin, crystals, 768 Cuckoo-pint, 437 Cucumber, 710 protein in, 199 squirting, 444, 709 sugar in, 156 tree, 540 sour, 612 Cucumis, 443, 710 Cucurbita, 443, 709 Cucurbitaceae, 708 Cudbear, 74 Cudrania, 516 Cud^weed, 446 Cultivated and wild plants, value of, 739 Cultivation of medicinal plants, 727 progress in, 744 Culver's root, 450, 689 Cumarin, 173 Cumin, 443, 643 oil, 643 Cuminum, 443, 643 Cunila, 443, 681 Cup or bur, 510 Cupana, 443 Cuphea, 628 . Cupule, 420 Curanga, 691 Curanjiin, 691 Curare, 662 INDEX. Curare poison, 539 Curarine, 662 Curatella, 615 Curcas, oil in, 213 Curcin, 198 Curcuma, 494 protein in, 200 Curcumin, 496 Currant, 457, 558 Buffalo, 558 fetid, 558 protein in, 199 sugar in, 156 Cuscuta, 670 Cuscutin, 670 Cusparia, 443, 585 Cusso, 443, 447, 565 Custard apple, 543 family, 541 Cutin, 277 Cutose, 257 Cyanol, F. F., 182 Cyanophyceas, 8 glycogen in, 154 Cyanus, 443 Cycads, iii Cyclamen, 656 hairs in, 282 Cydonia, 560 Cylindric leaves, 349 Cyme, 395 dibrachious, 395 helicoid, 395 monobrachious, 395 Cymene, 643 Cyminum, 443 Cynara, 726 Cynips, 511 Cynoglossine, 673 Cynoglossum, 443, 673 Cynomorium, 519 Cyperaceee, 472 Cyperus, 443, 472, 473 Cypripedium, 443, 496, 498, SOI Cystoliths, 200 Cystopus, 44 Cystotyles, 201 Cytases, 244 Cytisine, 575 Cytisus, 443, 569 Cytology, 138 Cytoplasm, 2, 135 Daisy, 712 fleabane, 713 white, 718, 724 Damascenus-a-u Damiana, 623 Damianin. 623 Dammar, black, 587 Dandelion, 460, 712 hairs in, 288 Daphne, 443, 627 Daphnin ^70 m. 443 8or D-arabinose, 169 park field illumination. 765 Date palm, 208. 473 endosperm in, 265 Dates. 475 Datisca, 625 Datiscacea;, 624 Datiscin, 169. 625 Datura. 443. 682. 684 ferment in, 244 Daucus. 443 Day-flower, 442. 480 Deadly nightshade. 684 Decandrus-a-um, 443 Deciduous. 388 Definite inflorescence, 394 Dehiscence. 41 1 Dehydrating agent. 755, 7S6 Delafields haematoxylm so- lution, 760 Delphinium. 443. 535. 574 Dentate. 356 Dentatus-a-um, 443 Dermatogen. 253 Derris. 575 Descent of plants. 133 Desmids. 17 Desmodium. 361. 443 Development, arrested. 391 of stomata. 368 Devil's apron. 30 Devonian age, 99 Dewberry. Xorlhern. 563 Dextrin. 147 Dextro-glucose, 155 Dextrose, 155. 563 Diandrous, 381 Dianthus, 443 species of, 531 Diaporthe parasitica. 54 Diastase, 242 Diatomaceous Earth, 38 Diatoms, 35 Dibrachious (cyme). 395 Dicentra, 443. 551 Dicotyledonous stem struc- ture. 339 Dicotyledons. 120, 501 ■Dictamus. 225. 443 Dicypellium. 544. 546 Didymus-a-um, 443 Didynamous. 381 Diervilla. 443. 707 Digitalin. 169. 170 Digitalis. 443. 690 hairs of. 284. 285 section of leaf. 37a seedlings. 743 Digitalose. 169 Digitonin. 169 Digitoxin. 169 Dill. 436 garden, 643 oil. 643 protem in, aoo 8o2 INDEX. Dilknia, 615 DilleniacesB, 615 Dimorphic flowers, 399 Dioicus-a-um, 444 Dionaea, 362, 554 Dioscorea, 444, 492 stem of, 322 Dioscoreaceae, 492 Diosphenol, 582 Diospyros, 444, 659 hairs in, 282 Dipentene, 722 Diphyllus-a-um, 444 Diplococci, 14 Dipsacaceae, 707 Dipsacus, 444, 708 Dipterocarpaceae, 620 Dipterocarpus, 620 Dirca, 444, 627 Disaccharose, 154 Discaria, 606 Discoid head, 711 Disk-flower, 711 Dissepiment, 411, 378 false, 378 Dissotis, 634 Distichous, 363 Dita, 435 Ditch stonecrop, 454. SS6 Dittany, 443 American, 682 Divergence, 363 Divided, 356 Divi-divi, tannin in, 206 Divining rod, 558 Division, internal, 5 Doassansia, 67 Dock, curled, 523 sorrel, 458 Dodder, 670 Dogbane, 436 family, 664 spreading, 664 Dog's-tooth violet, 485 Dogwood, 442 family, 643 flowering, 643 Jamaica, 448, 575 Domesticus-a-um, 444 Domingensis-e, 444 Doona, 621 Dorema, 444, 639 Dorsal pneumatic tissue, 366 suture, 377 Dorsiventral flowers, 393 leaves, 349, 366 Dorstenia, 444 Double flowers, 714 staining, 762 Douglas fir, 114 spruce, 119 Dracaeno, 489 Dracontomelum, 599 Dragon's blood, 474, 488 Dragon tree, 489 Drimys, 540 Drosera, 361, 444. 554 Droseraceae, 554 Drugs, curing of, 738 drying of, 737. 738 physiological testing of, 248 selection of, 737 Drupe, 418, 426 Druzenzotten, 222 Dryobalanops, 620 Dryopteris, 87, 90, 92, 444 hairs of, 284 Dry yeast, lecithin in, 214 Duckweed, 450 family, 478 Ducts (see Tracheae), 273 Dulcamara, 444, 684 Dulce, Irish, 34 Dulcis-e, 444 Dulcitol, 156 Duration of calyx and corolla, 388 Dutch clover, 472 Dutchman's breeches, 550 Dwarf branch, 374 Dye, leather, 633 Dyer's broom, 574 Dyes, aniline, as staining agents, 757 non-aniline, as staining agents, 757 Dyna-Tiic centers of cell, 140 Dysentericus-a-um, 444 Dzaini, 562 Early sweet blueberry, 653 Eau D'Ange, 632 de Creole, 620 Ebenaceae, 444, 659 Ebenales, 658 Ebony, 444, 659 black, 659 family, 659 green, 659 red, 659 striped, 659 white, 659 Ecballium, 444, 709 Echinacea, 723 oil canals in, 224 phytomelane in, 260 Echinate, 354 Echinocarpus, 607 Ecology. I Edestin, 195 Eelgrass, 466 Egg apparatus, 298 cell, 124, 298 plant, 688 Elaeagnaceae, 628 Elaeagnus, 628 Elaeis, 474 Elaeocarpaceae, 607 Elaeocarpus, 608 Elastic, 444 Elastica. 241, 592 Elasticity, 774 Elasticus-a-um, 444 Elaterin, 709 Elaterium, 444, 709 Elaters, 82 Elder. 458 American, 706 black, 706 mountain, 706 red-berried, 706 Elecampane, 448, 720 Elemi, Bengal, 586 Manila, 586 resin, 586 West India, 586 Eleocharis, 444. 472 Elettaria, 444, 494 Eleusine, 467 Elm, 461, 512 American, 512 cross-section of wood, 34<5 family, 512 slippery, 513 white, 512 Eluteria, 444 Emarginate, 355 Emasculated, 451 Embryo-sac, 108, 120, 298 Emodin, 170 Emulsins, 243 Enchanter's nightshade, 634 Endocarp, 410 Endodermis, 310 Endosmosis, 251 Endosperm, 108, 127, 425 of date palm, 265 structure of, 429 Endospore, 12, 41 Endothecium, 404 Endothia radicalis, 54 Entada, 575 Enterolobium, 575 Entomophilous, 402 Environment, 130 Enzymes, 241 diastatic, 242 Eperua, 576 Ephemeral, 388 Epicarp, 410 Epicotyl, 299, 426 Epidermal cells, 277 Epidermis, 309, 369 Epigaea, 444. 644. 649 Epigeous shoot, 321, 32a Epigynous, 389 Epilobium, 634 Epipactis, 503 Epiphytes, 306 Equisetaceae, 444 Equisetales, 96 Equisetums, 96, 444 Equitant leaves, 349 Erectus-a-um, 444 INDEX. 803 Ergot, 52, I5S, 441, 444 Ericaceae, 444, 644 microsublimates of, 173 Ericales, 644 Ericolin, 655 Erigeron, 444, 713 Eriobotyra, 562 Eriodendron, 611 Eriodictyon, 444, 670 hairs of, 284, 286 Erysimum, 445, 553 Erytaurin, 664 Erythreea, 664 Erythronium, 485 Erythrophloeum, 575 Erythroxylaceas, 580 Erythroxylon, 445, 580 Eschscholtzia, 547, 550 Esculentus-a-um, 445 Esparto, 472 Esters, 234 Estivation, 389 Etaerio, 419 Ether, phenol, 234 Euasci, 47 Eucalyptol, 631 Eucalyptus, 445, 631 kino, 631 oil, 631 seedling, 745 species of, 631 Eucitrus, 583 Eugenia, 445, 631 Eugenol, 234, 544, 546 Euonymus, 239, 445, 600 Eupatorin, 713 Eupatorium, 44s, 712 Euphorbia, 445, 591, 592, 594 Euphorbiaceae, 590 Euphorbium, 593 Euphorbon, 593 Europasus-a-um, 445 Euryale, 532 Evening primrose, 436, 634, 635 family, 634 Evergreen, 459 Evernia, 73 Evolution, 129, 247 Excelsin, 195 Excelsus-a-um, 445 Excoecaria, 592 Exine, 123, 404 Exocarp, 410 Exodermis, 309 Exogonium, 445, 668 Exosmosis, 251 Exospores, 41 Exothecium, 404 Experimental farms, 732- 735 Extraordinary ray, 774 Extrorse, 380 Fabiana, 684 Fagaceae, 511 Fagales, 510 Fagopyrum, 445, 526, 527 Fagus. 445 species of, 512 Fairy-ring fungus, 58 False beech-drops, 644 dissepiment, 378 flax, 439 hellebore, 462, 537 indigo, 435, 438 mitre wort, 460, 556 nettle, 438 Solomon's seal, 484, 485 spikenard, 484 unicorn root. 491 winter's bark, 622 Fan palms, 473 Farfara, 445 Farinosae, 480 Farinosus-a-um, 44s Farms, experiniental, 732- 735 Fastigiatus-a-um, 445 Fats, 210 physiology, 216 Fatty oils, 546 resins, 238 Fegatella, 272 Fennel, 445. 639 fiower, 453 protein in, 200 Ferments, 241 in stinging hairs, 287 in yeast, 49 microchemistry of, 245 Fern, flowering, 454 fossil, 104 male, 445 palms. III sensitive, 453 used in medicine, 96 walking, 92 water, 94 Fertile, 121 Fertilis-e, 445 Fertilization, 125, 397 Ferula, 445, 639 Fetid, 445 Fever bush, 438 hay, 726 Fibers, bast, 268 isolation of, 270 sclerenchymatous, 268,270 strength of, 269 Fibrovascular strand, 313 Ficus. 241, 445. 513.514.51S ferment in. 244 latex in. 240 species of. 516 Field sorrel, 524. 525 penny cress, 553 Fig. '515 ferment m. 244 Pig. Indian. 626, 627 protein in. 199 Figwort family. 688 Fiji oil. 519 Filament. 379, 404 Filbert. 442, 510 Filicales. 87 Filix-mas, 445 Fir. 213. 434 California silver, iia red. 1 19 Scotch, 1 17 tannin in. 206 white. 1 19 Fisetin. 180 Fishberries. 539 Fish poison, 517, 539, 604, 606 Fistula. 445 Fixing agents. 755 Flacourtiaceae. 622 Flats, plant. 730 Flavon. 170 Flavone. 180 Flax. 450 family, 579 Flaxseed, oil in. 213 protein in, 199 structure of, 428 Fleabane, 444 Canada, 713 daisy, 713 Philadelphia, 713 sweet scabious, 713 Flea seed, 456 Fleur-de-lis, 448 Floral envelopes, 382 leaves. I20, 375 Florets, 711 Florida moss, 480 Flour, gluten. 196 Graham. 196 Flower. 374 Flowers, classes of. 393 cleistogamous. 391 complete. 392 diagrams, 505 double. 390. 714 inner structure of. 402 insect, 718 ligulate, 395. 711 of Angiosperms, 375 of Compositaf. 387 of Gymnosperms, 375 of Solanacea?. 385 outer morphology of, 374 parts of. 374 stalks. 376. 402 sun. 447 tubular. 39 '. 711 types of, 3iji Flueggea. 593 Foeniculum. 44s. 639 aleurone grains of, 194 Foetida, 629 8o4 INDEX. Foetidus-a-um, 44s Fog-fruit, 450 Folia Malabanthri, 568 Follicle, 419 Fontinalis, 85 Food, bird. 696 of plants, 248 Fore-leaves, 393, 466 Forget-me-not, 453, 670 Formaldehyde, 234 Forms of leaves, 354 of plants, alterations in, 332 Fossil Coniferae, 119 Fouquieria, 621 Four o'clock family, S28 Foxglove, 443, 690 Fragaria, 445. 566 fruit, 415 species of, 567 Fragilaria, 37 Fragrance due to volatile oils, 234 Fragrans, 445 Fragrant, 445 Frames, cold, 731 Frangula, 445 Frangulin, 169, 170 Frankincense, 587 Frasera, 445 Fraseri, 446 Fraxetin, 661 Fraxin, 169, 170, 661 Fraxinus, 446, 661 glandular hairs in, 230 Fremontia, 615 French plum, 562 Fringe tree, 441, 661 Fructose, 154. I55 Fructosidase, 242 Fruit acids, 563 ethers, 564 jellies, 243 outer morphology of, 408 structure of, 421 sugars, 155. 563 Fruits, classification of, 421 different types of, 409 Fuchsia, 634 Fuchsin, as staining agent, 757 Fucose, 154 Fuller's teasel, 708 Fulvus-a-um, 446 Fumaria, 209, 446, 547, 550 Fumariaceae, 209 Fumarine. 548, 550 Fumitoiy, 446, 550 European, 550 Funaria, 85 Function of leaf, 350 Fungi, 7, 40 constituents of 41 coral, 58, 59 detection of, 70 Fungi, economic uses, 65 edible, 59 ferments of, 242, 244 gill, glycogen in, 154 groups of, 41 imperfecti, 70 jelly, 59 leather, 59 poisonous, 61 pore, 59 rust, 65, 68 smut, 65 stinck-horn, 59 Fungus chirurgorum, 65 Funifera, 627 Fusanus, 519 Fustin, 169. 170 Galactose, 169 Galangal, 494 Galbalus, 419 Galbanum, 639 Galeopsis, 446 Galetae, 388 Galium, 446, 697. 704 Gallicus-a-um, 446 Galls, 206, 334, 446, 511 Chinese, 597 crown, 335 fungus, 334 hard. 334 Japanese, 597 of Terminalia, 633 soft, 334 Gamboge, 597, 618, 619 Gamete, 5, 298 Gametophyte, 75. 108, 298 Gamopetalous. 385 Gamosepalous, 385 Garcinia. 446. 618, 619, 6-0 Garden bean, 576 beets, protein in, 199 heliotrope, 670 lilac, 661 pea, 576 rue, 585 strawberry, 566 Gardenia, 446, 704 Garlic, 435. 485 mustard, 553 protein in, 199 Gaultherase, 243, 644 Gaultheria, 446, 644, 650 Gaultherin, 169, 170 Gaylussacia, 446, 652 fruit, 414 Gelidium, 34 Gelsemium, 446, 661 Genista, 446, 574. 575 Gentian, 446, 663 American, 664 bottle, 663 closed, 663 Gentian family, 663 fringed, 664 horse, 706 rhizome of, 331 . violet, as staining agent, 757 yellow, 663 Gentianacese, 663 Gentianales, 660 Gentinin, 169 Gentisein, 180 Geotropism, negative, 320 positive, 302 Geraniaceae, 578 Geraniales, 577 Geraniol, 233. 564. 579. 583 Geranium, 446. 571 family, 578 fruit, 409 grass oil, 472 hairs in, 282 rose, 579 Geranyl acetate, 234 Gerardia. purple, 693 German chamomile. 715 Germander. 460 Germination, time of, 730 Geum, 446 Gigartina, 33. 446 Gilead balsam, 587 Ginger, 462, 494 beer, 49 family, 494 grass oil, 472 protein in, 200 starch in, 148 wild, 437, 520 Ginseng, 305, 454. 636, 638 cultivation of, 735 family, 636 Girardinia, 517 Githago, 446 Glaber-bra-brum, 446 Glabrous, 369 Glaeocapsa, 72 Glandular, 354 Glandulifer-a-um, 446 Glandulosus-a-um, 446 Glans. 420 Glaucium, 446, 550 Glaucous, 370 Glechoma, 681 Gleditschia, 575 Gliadins, 195 Globe artichoke, 726 Globoids, 193 Globulins, 192 Globulus, 446 Gloeocapsa, 8 Gloiopeltis, 34 Gluco-alkaloids, 172 Glucose, 154 Glucosidal resins, 238 Glucosidase, 242 Glucoside, 155, 167 Glucoside, classification 169 dextrose, 169 distribution of. 169 function of. 172 microchemistry of, 171 rhamnose, 169 Glumes, 466 Glumiflorae, 466 Glutamin, 253 Glutelins, 194, 195 Gluten. 196 flour. 196 Glutinosus-a-um, 446 Glutinous. 446 Glycerin-jelly, 763 Glycine, 576 Glycinin, 195 Glycocoll, 192 Glycogen, 154 Glj^coside, 167 Glycyphyllin. 169 Glycyrrhiza, 446, 568 Gnaphalium, 446 Gnidia, 627 Goa powder, 441 Goat's beard, 461 Goldenrod. 459, 712. 726 anise-scented, 722 high, 721 Golden seal, 448. 532 Gold flower. 441 Goldthread, 442 Gonidium. 71 Goodyera, 503 Gooseberry. 457, 557 fruit, 418 . protein in, 199 sugar in, 156 Goosefoot. 441, 527 Gossypitrin, 169 Gossypium, 447, 610 fiber, 269 Gouania, 447, 606 Gourd, 443 family, 708 Gracilaria, 34 Graham flour, 196 Grain, 417 pollen, 298 Graminales. 466 Gramineae, 447, 466 Granatum, 447, 629 Grape, 462, 606 fern, Virginia, 365 fruit. 584 protein in, 199 seed, oil in. 213 sugar. 155. 606 sugar in. 156 vine, 606 Grass. 447 beard, 436 family, 466 holy, 448 INDEX. of. Grass of Parnassus. 556 panic, 454 pepper. 450, 553 scurvy. 442. 553 sweet vernal, 436 worm, 459 Gratiola, 447, 691 Gratiolin. 691 Graveolens. 446 Gravity, influence of. 301 Greek valerian, 671 Grenacher's borax-carmine solution, 760 hasmatoxylin solution t6o Grevillea, 518 Grewia, 609 Grias. 629 Griffithsia. 40 Grimmia, 85 Grindelia, 447, 713 Gromwell, 450 Groundsel, 459 tree, 437 Growing point, 253 Growth, factors influencing, 246. 247 Guaiac, 447 Guaiacum, 447, 580. 581 Guarana, 162. 447. 454, 603 ' Guarea, 516 Guava. 632 Guayava, 632 Guazuma, 615 Guelder-rose, wild, 704 Gulf weed. 31 Gum. 218. 565. 599 acajou, 599 anacardium. 223 arable, 222, 569 balata, 659 chagual. 223 chewing, 659 chicle. 659 cocoa-palm. 223 East Indian, 223 exuding. 447 moringa. 22^ plant, 447 red, 574 resin, 225, 236 spruce, 119 tragacanth, 218, 569. 570 tree, sweet, 558 yellow, 574 Gumbo, 61 1 Gummifer-a-um. 447 Gummy. 444 Gurjun balsam, 621 Gurjunic acid, 621 Gutta-percha, 241, 658 Guttifera:, 618 Guvacine. 474 Gymnocladus, 447, 575 Gymnosperms. loi S(.3 Gymnosperms. flowers of 375 groups of, 1 1 J Gymnosporangium. 115 Gynaecium, 376 Gynandrous. 382 Gynocardia. 623 Gypsophila. 447. 53, Gysbertsiana. 621 Habenaiia. 447. 499. soo Hadrome. 3 i 2 Haematoxylin, 180 Haematoxylon. 447. 571 Hagenia. 447. 565. 566 Hairs, abictiform, 287 candelabra, 287 crystal containing, 287 false plant, 290 glandular, 222. 228. 281 hooked. 286 lignified. 290 nonglandular. 283 papillose. 286 peltate. 286 plant, 275 shaggy. 28s stellate, 286 stinging. 287 types of. 281 uniseriate. 286 Hamamelidaceae. 558 Hamamelis, 447. 558. $59 Hanburii. 447 Hand microtome. 749 Hardening agent. 755. 756 Hard galls. 334 Hardhock, 459 Hard rush. 493 Hardwickia, 571 Harvesting of crops. 738 Hashish. 516 Haustoria, 306. 518 Haw. black. 704 Hawthorn. 442. 565 Hay fever. 726 Hazelnut. 442. 510 Chilian. 518 oil in. 213 protein in. 199 Hazel wort. 437 Head. 395 Heart's ease. 462 Heath 444 family. 644 Heather. 439 Hedeoma. 447. 676 Hedera. 447. 636 Hcderic acid. O36 Hedge hyssop. 447. 452 Helenium, 447. 723 Ht'lianthemum. 447 Hehanthenm. 150. 726 Hclianthus. 447. 725 Helicteres. 615 8o6 INDEX. Heliotrope, 447 garden, 670 Heliotropism, 349 Heliotropium, 447, 670 Helixin, 636 Hellebore, 447 black, 537 false, 537 Helleborein, 537 Helleborus. 447, 537 Helonias, 491 Hemiasci, 47 Hemlock. 113, 461 poison, A42, 638, 640 tannin in, 205, 206 (Tsuga). 119 water, 441, 575, 642 Hemp, 439 fiber, 269, 514 nettle, 446 oil in, 213 sisal, 492 yellow, 625 Hempwood, climbing, 452 Henbane, 448. 684 Henequen, 492 Henna plant, 629 Hepaticae, 80, 447 Herb, annual, 329. 330 biennial, 330 perennial, 330 quinine, 664 Herba Centaurii Minoris, 664 cochlearise. 553 Herbaceous. 447 Herbaceus-a-um, 447 Herbs, 329 Hercules, club of, 441 Hermaphrodite, 392 Herniaria, 531 Hesperidin, 151. 169, 170, 585 Hesperidium, 419 Hesperis, 447. 583 hairs in, 282 Heterocysts, 11 Heterosporous, 87 Heuchera, 447. 556 Hevea. 241. 447, 592, 594 Hexose, 154 Hibiscus, 448, 611 Hickory, 333. 509 cross-section of wood, 346 Hicoria, 365. 509. 5 10 Hierochloe, 448, 472 High-bush huckleberry, 652 Hilum, 425 of starch grain, 144 Hinna, 629 Hippocastanaceae, 602 Hippocastanum, 448 Hirsute, 354 Hirsutus-a-um, 448 Hispid, 354 Hispidus-a-um, 448 Histology, 1 Hoarhound, white, 676 Hold-fast, 30 Holly, 448 American, 600 Christmas, 600 dahoon, 600 European, 600 family, 600 leaved barberry, 436 Hollyhock, 435. 609, 611 Homalium, 623 Honesty, 553, 554 Honey, 402 dew, 157 poison, 402 Honeysuckle, 450 bush, 443. 707 family, 704 Hopea, 621 Hop, hornbeam, 454 substitute, 606, 621 tree, 585 Hops, 448, 515 Hordeum, 448, 467, 468 Horehound, fetid, 437 water, 451 Hornbeam, 440, 510 Horsebalm, 442 chestnut, 434, 448, 602 gentian, 706 mint, 679 radish, 553 tails, 96, 444 Hound's tongue, 443, 673 Houstonia, 448, 697 Hoyer's picro-carmine solu- tion, 760 Huckleberry, 446, 654 black, 652 fruit, 414 sugar in, 156 Humulene, 508, 509 Humulus, 448. 514 hairs in, 282 Humus, 249 Hura, 592 Hyacinth, 485 Hydnocarpus, 623 Hydrangea, 448, 556 wild, 556 Hydrangin, 556 Hydrastine, 162, 770 Hydrastis, 161, 448, 532 alkaloids, 174. I75 farming, 734. 735 Hydrochinon, 176 Hydrodictyon, 22 Hydrophilous, 401 Hydrophyllaceae, 670 Hydropiper, 448 Hymenenaea, 574 Hymenium, 57 Hymenocallis, 448, 492 Hyoscyamufi. 38s. 448, 684 branching hairs in. 289 fruit, 409, 412 structure of seed, 429 tracheae of, 274 Hypecoum, 547 Hypericaceae, 618, 620 Hypericum, 448, 620 Hypha, 41 Hypnum, 85 Hypocotyl, 299, 426 Hypocratenform, 388 Hypodermis, 309 Hypogeous shoot, 321, 325 Hyssop, 691 garden, 679 Hyssopus, glandular hairs in, 230 hesperidin in, 153 Ice-plant. 529 Icthyomethia, 448 Idaeus, 448 Idioblasts, 207. 208 Ilex, 448, 600, 601 Ilicaceae, 600 Ilicin, 600 Illicium. 448, 540 Illipe, 659 Imbricated, 389 Impari-pinnate, 357 Impatiens, 448, 604 Imperfect flower, 392 Incumbent, 427 Indefinite inflorescence, 394 Index, refractive, 774 India Bdellium, 587 rubber, 516, 592 senna, 567 Indian cress, 579 cucumber, 485 root, 435 fig, 626, 627 hemp, 436 licorice, 434 mallow, 610 pipe, 452, 644 Suringi, 620 tobacco, 710 turnip, 477. 480 Indican, 169, 574 Indicus-a-um, 448 Indigo, 527. 573 blue, 180, 574 forming glucoside, 553 wild, 573 Indigofera, 573 tinctoria, 180 Indigotin, 180 Inflatus-a-um, 448 Inflorescence, 393. 394 Influence of gravity, 301 Infundibuliform, 388 Infusorial earth, 38 Inhambane copal. 574 Injury to plants. 172 Ink-ball. 335, 512 gall, 335. S12 tree, 597 Innate, 381 Inner structure of leaf. 365 of root, 309 of stem, 338 Inosit. 607, 636 Insect flowers. 718 Insect visitation of flowers, 399 Insectivorous plants, fer- ments in, 244 Intine, 404 Intrafascicular cambium, 34 1 Inula, 387, 448, 720 hairs in, 288 phytomelane in, 261 Inulenin, 150, 726 Inulin, 150, 72s Inulinase, 242 Invertase, 242 Involucre, 395 Involute, 364 Iodine in seaweeds, 40 solution, 761 in water, 760, 761 lonon. 622 Ipecac. 448. 699 wild, 706 Ipecacuanha. 440, 448 Ipomoea, 448 Iridaceas, 492 Iridin, 169 Iris, 332, 448, 492 Iron solutions, 761 Irone, 234 Ironwood, 454, 510. 659 Irregular flower, 393 Irritability, 358 Irvingia, 586 Isatis. 553 Islandicus-a-um, 448 Isoetes, 97, 449 Isometric system, 764 Isoptera, 621 Isoquinoline, 166, 180 Isosporous, 87 Iva, 448 Ivory, vegetable, endosperm in, 26s Ivy, 441, 447 English, 636 ground, 681 poison, 595, 596 Ixina, 449 Jaborandi, 449, 455, 582 Jacaranda, 691 Jack-in-the-pulpit, 477 Jack-tree, 516 Jalapa, 449 substitute, 528 Jamaica dogwood, 575 INDEX. Jambosa, 631 Jambuse berries, 632 Japanese lacquer, 597 medlar, 562 3Dy bean, 576 Japan-wax, 212 Jateorhiza, 539 Jatropha, 591 Jellies, fruit, 243 Jelly, Kaiser's glycerin, 763 Jequirity, 575 Jessamine, yellow, 661 Jewel-weed family, 604 Jimson weed, 443, 684 Joannesia, 591 Juglandales, 509 Juglans. 449. 509. 510 cross-section of wood, 346 Juglansin, 195 Juglon, 179 Julocroton, hairs in, 282 Juncaceae, 493 Juncus, 493 Jungermania, 83, 85 Juniper, 116 Juniperus, 118 Jussieua, 634 Jute fiber, 269 807 Kadsura, 540 Kaiser's glycerin-jelly. 763 Kalmia, 174. 449, 648 Kamala. 449, 45i. 592 hairs of. 285 Kapac oil, 611 Kavaine, 508 Kava-kava, 177, 452, 508 Ketones, 234 Kidney bean, protein in, 199 Kiggelaria, 623 Killing agent, 755 Kinic acid. 655 Kino. 449, 569 American. 569. 571 Brazil, 593 eucalyptus, 631 Kittool, 476 Kittul. 476 Kiurushi, 597 Kleister, 145 Knot weed, 456 Kola nut tree, 614 Krameria, 449. 571 Kraunhia. 575 Kristallsand, 188 Kuhnia, 449 Kuhnistera, 449 Kumquat orange, 584 Labellum, 388 Labiatae, 449, 673 Laburnum, 575 Lac, 597 Japanese, 597 tree, 245 Laccase, 597 Laccases, 245 Lace-tree. 628 Lacinaria, 449, 722 Laciniatus-a-um. 449 Lacquer, black. 24s Japanese. 597 trees, 597 Lactarius. 65 Lactuca, 449, 712 milk-juice of, 241 Lactucarium, 241. 449 712 Lady's mantle. 435 slipper. 443 thumb, 455 Laetia, 623 Laevulose, 155 Lafaensia, 628 Lagerstroemia, 629 Lagetta. 628 Lamellae, 259 middle, 254 secondary. 255 Lamina. 348. 385 Laminaria, 30 Lamium, 449 Lanate, 354 Lanceolatus-a-um, 449 Landolphia, 241 Langsdorffia, 519 Langsdorffii. 449. 571 Laplaceae, 618 Laportea, 449, 517 Lappa, 449 Larch, tannin in, 206 Larix, 118 Larkspur, 443. 535. 574 Lateral branches. 312 root. 301. 312 Laterifolius-a-um. 449 Laticiferous vessels. 240 Latex. 238. 546 Lathyrus. 450. 576 Lauraceze. 450. 544 Laurel. 450. 544 bay. 461 great, 647 ground, 444 mountain, 648 noble, 544 nut, 212 oil. 619 sheep. 449. 648 spurge. 627 Laurus, 544 Lavandula. 450 hairs in. 282. 284 Lavender. 450. 676 pollen of, 404 sea. 450 spike. 676 true. 676 Lawsonia, 450. 620 Layer, resinogenous, 226 Leaf, apex of. 354 8o8 INDEX. Leaf, base of, 3S6 bifacial, 366 climber, 324 dorsiventral, 366 functions of, 350 inner structure of, 36s margin of, 356 mold, formation of, 249 netted-veined, 353 outer mofphology of leaf, 348 palmi-nerved, 353 parallel- veined, 352 reticulate, 353 simple. 348 teeth, glandular, 283 unifacial, 366 venation, 352 Leaflets, 356 Leather, dye, 633 wood, 444, 627 Leaves, 299. 348 anatomical differences in, 370 autumn, 178 bifacial, 349 compound, 356 cylindric, 349 decay of, 250 divergence of, 363 dorsiventral, 349 equitant, 349 foliage, 120 forms of, 354 modified, 364 movement of, 357 scale, 120 sporangial, 120 surface of, 353 sword-shaped, 349 texture of, 354 Lecanora, 74 Lecidea, 75 Lecithin. 214 Lecythidaceae, 629 Lecythis, 629 Ledum, 450 Leek, 485 Legume, 419 Legumelin, I95 Legumin, 195, 576 Leguminosae. 450, 567, 575 Lemna, 300 Lemnaceae, 450, 478 Lemon, 450, 584 oil, 584 protein in, 199 Lens, 450. 576 Lenticels. 291, 292 Lenticus, 450 Lentil, 450, 576 protein in, 199 starch in, 148 sugar in, 157 Lentus-a-um, 450 Lenzites, 62 Leontin, 538 Leonurus. 450, 682 Lepargyraea, 628 Lepidium, 450, 544 Lepidodendron, 100 Leptandra, 450, 689 Leptilon, 713 Leptome, 276, 312 Leptospermum, 632 Lettuce, 449 poison, 712 Leucadendron, 450, 5i7 Leucaena, 575 Leuco-compounds, i79 Leucoplastids, 136, I37 Leucosin, I95 Leucospermum, 518 Leucothoe, 648 Levisticum, 450, 643 Levo-glucose, IS5 Levulose, iSS. 563 Lianas, 324 Liane, 324. 602 Libriform, 270 Lichens, 71 color in, I79 economic uses of, 73 on Rhamnus Purshianus, 292 roots of, 73 Licorice, 568 fern, 96 section of, 271 Spanish, 568 wild, 704 Life-processes, 134 Light relation of leaves, 349 shoot, 329 Lignin, 256, 580 Lignocellulose, 256 Lignone, 256 Ligulate flower, 711 Ligule, 356 Liguliflorae, 711 Ligusticum, 450 Ligustrum, 450, 661 Lilac, 466 garden. 661 Liliaceae, 450, 485 Liliales, 485 Liliiflorae, 485 Lilium, 485 Lily, 450, 485 lotus, 453 of the valley. 442, 485. 487 spider, 448 yellow pond, 453 Lima beans, protein in, 199 Limb, 386 Lime fruit, 584 tree, 608 Limnophila, 358 Limonene, 583 Limonium, 4SQ Limonum, 450, 584 Linaceae, 450, 579 Linalool, 233, 564, 583 Linalyl acetate, 234 Linamarin, 169 Linaria. 691 Linariin, 691 Linden, 461, 608, 609 hesperidin in, 153 Lindera, 544 Linen, 580 Linodendron, 628 Linseed, oil in, 213 Linum, 579 structure of, 428 Lion's foot, 723 Lippia, 450, 673 Lippiol, 673 Liquidambar, 450, 558 Liquorice (see Licorice) Liriodendrin, 540 Liriodendron, 450, 539 Lithospermum, 450 Litmus, 74 Litsea, 546 Liverworts. 76, 80, 82, 83 Lobed, 356 Lobelia, 384. 450, 710 blue, 710 red, 710 section of leaf, 370 seed-coat, 429 Lobeliaceae, 450 Loco, 574. 575 Loculicidal, 412 Locust, 457, 567, 576 Loeffler's methylene blue, 757 Logania, 450, 661 Loganiaceae, 450, 661 Logwood, 571 Lomatia. 518 Lonchocarpus, 575 Lonicera, 450, 707 Loosestrife, 451, 628 purple, 628 Lophophora, 625 Lophophorine, 625 Loranthaceae, 450, 518 Loranthus, 518 Lotus, 450, 532 Lovage, 450, 643 Lucerne, 577 Luffa, 710 Luffa-sponge, 710 Lumen, false, 269 Lunaria, 450, 553. 554 Lungwort, 456 Lupeol acetate, 659 Lupine, 451. 574 seeds, lecithin in, 214 Lupinidine, 575 Lupinin, 575 Lupinine, 575 Lupinus, 451, S7S INDEX.