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McGRAW-HILL PUBLICATIONS IN THE 

BOTANICAL SCIENCES 
EDMUND W. SINNOTT, CONSULTING EDITOR 



Flowers 
and Flowering Plants 



SELECTED TITLES FROM 

McGRAW-HILL PUBLICATIONS IN THE 
BOTANICAL SCIENCES 

EDMUND W. SINNOTT, Consulting Editor 



Babcock and Clausen Genetics 
Belling The Use of the Microscope 

Boy sen Jensen Growth Hormones 

in Plants 
Braun-Blanquet and Fuller and Con- 

ard Plant Sociology 
Curtis The Transloeation of Solutes 

in Plants 

Eames Morphology of Vascular 

Plants 
Eames and MacDamels Plant 

Anatomy 
Fitzpatrick The Lower Fungi 

Gaumann and Dodge Comparative 

Morphology of Fungi 
Haupt An Introduction to Botany 

Haupt Laboratory Manual of Ele- 
mentary Botany 
HiU Economic Botany 
Hill, Overholts, and Popp Botany 
Johanwn Plant Microtechnique 
Loomis and Shull Methods in Plant 
Physiology 
Experiments m Plant Physiology 



Lutman Microbiology 
MaximovP\Knt Physiology 
Miller Plant Physiology 
Pool Flowers and Flow ei ing Plants 

*SVi.\s Elements of Botanical Micro- 
tech inqiie 

Seifriz Pro toplasm 
Sharp Cytology 
Smnott Botany 
Sinnott and Dunn Genetics 
Smith Crypt ogamic Botany 

Vol. T, Algae and Fungi 
Vol IT, Biyophytes and 

Ptcridophytes 
Fresh-water Algae of the U. S 

Swingle Systematic Botany 

Weaver Root Development of Field 
Crops 

Weaver and Brumr Root Develop- 
ment of Vegetable Crops 

Weaver and Clements Plant Ecology 

Wodehouse Pollen Grains 



There are also the related series of McGraw-Hill Publications in the Zoologi- 
cal Sciences, of which A. Franklin Shull is Consulting Editor, and in the 
Agricultural Sciences, of which Leon J. Cole is Consulting Editor. 




Frontispiece 



CHARLES EDWIN BESSEY 
1845-1915 



Dr. Bessey proposed the main features of the outline of classification 
that is adopted in this book. 



Flowers 
and Flowering Plants 

An Introduction to the Mature and Work of Flowers 
and the Classification of Flowering Plants 



BY 

RAYMOND J. POOL, PH.D. 

Professor of Kotany and Chairman, Department of Botany 
University of Nebraska 



SECOND EDITION 
SECOND IMPRESSION 



McGRAW-HILL BOOK COMPANY, INC. 

NEW YORK AND LONDON 
1941 



FLOWKKS AND FLOWKKL\G PLANTS 

CoPYRtOHT, 1929, 1041, KY THE 

McGitAvv-HiivL BOOK COMPANY, INC. 

PUINTKD IN THE UN1TKD STATErt OK AMERICA 

All right $ reserved. This book, ot 

parts f hereof, way not l)e reproduced 

in any fonn without permission of 

the publishes 



THE MAPLE PRESS COMPANY, YORK, FA. 



TO THE MEMORY OF M\ F \THKR AND MOTHER 

WILLIAM HENRY POOL 

\ND 

MARY LOUISA POOL 

PIONEERS OF THE PRAIRIES \\IIOSE ,s VnilFirKh 
MADE MY S( 1 HOOLIN(1 1'OSSIBl ^ 

AND 

TO THE MEMORY OF A (JREAT TEACHER 

CHARLES EDWIN BESSEY 

WHO LEI) ME TOU A TIME 
IOWABD NATURE'S EXPANDING HORIZON 



PREFACE TO THE SECOND EDITION 

The publication of a new edition of this book has afforded an 
opportunity to incorporate new material and to make certain 
other modifications which reflect suggestions that have been 
gratefully received from teachers throughout the country. The 
author regrets that he was unable to introduce all the* proposals 
made by his friends in other institutions. 

An entirely new chapter has been added in order to present a 
brief treatment of the more prominent vegetative features that are 
helpful in taxonomic work. A change that will be revealed by 
casual examination affects the large, folded chart. This has 
been simplified and illustrated so that it is not quite so much of a 
"puzzle" to the student who is beginning work of this kind. A 
new diagram has also been introduced (page 352) in order to 
present an interpretation of the ape talons, diclinous, and anemoph- 
ilous groups that is not shown in the preceding outline. The 
map showing the ranges of various floras and manuals (Fig. 211) 
has been revised to include a few important additions to the 
growing literature in that phase of the subject. To the reference 
books rioted in the first edition has been added a short list of 
valuable American works that have been published since 1929. 

The two short chapters dealing with an outline of the history 
of classification have been moved to a position immediately 
following the treatment of the various groups of flowering plants. 
This change makes for more continuity in the treatment of the 
principal material of the book. 

In response to requests from many students and from other 
teachers who have used the book there has been added a brief 
glossary which includes the more important terms used in the 
book. 

RAYMOND J. POOL. 

LINCOLN, NEBRASKA, 
April, 1941. 



PREFACE TO THE FIRST EDITION 

The field of biology involved in this book is clearly indicated 
by its title, Flowers and Flowering Plants, and its purpose and 
general content by its subtitle, An Introduction to the Nature and 
Work of Flowers and the Classification of Flowering Plants. 

The book is largely the outcome of a vigorous arid constant 
desire to interest college students and others in the essential 
nature, development, and classification of flowering plants during 
the past twenty-two years. The* author has found attractive 
opportunities herein for the presentation of the essential features 
of the .scientific mood and method in general along with our 
study of these plants. Certainly, few other groups of objects 
supply more attractive and useful materials for these purposes. 

Botanical science has been bountifully fruitful in the past, 
but someone has said that "the productive natural scientist 
himself has done little to impart to the people at large the living 
spirit which animates his labor, the instructive philosophy 
which guides it, or the methods which make it effective." In so 
far as a comprehension of the flowering plant world is concerned 
I fear that this is notably true. Possibly this well-known situa- 
tion is due in considerable degree to the fact that taxonomists 
have lost themselves so completolv in codes, congresses^ and 
conservandn. It is to be regretted that this is so largely true 
for that subdivision of botany that should make the vegetable 
kingdom a well-known realm to intelligent folks who really wish 
to know it. 

The conception of a flowering plant as a living, working 
mechanism and as a more or less plastic entity leads naturally 
to an interest in plants as units of life, and, therefore, in the 
possibility of grouping them into various subdivisions which 
may portray something of the more or less natural interrelation- 
ships of various degrees. An appreciation of plant relationships 
should do much to excite further observation and study wherever 
one may go. Men have sought such relationships for centuries. 
My experience teaches me that college students and others are 
really interested in the relationships that are so conspicuous 
among flowers. 



xii PREFACE TO THE FIRST 

I am fully aware of the fact that botanists are not yet in pos- 
session of the information that would enable them to construct a 
phylogenetlc classification of the flowering plants in which the 
origin and position of each group and the sequence of develop- 
ment can be clearly established by critical examination of all 
the evidence possible to secure. The evidence from anatomy, 
morphology, geology, geography, serum analysis, and genetics is 
slowly accumulating that will perhaps render such a classification 
possible sometime in the far-distant future. As yet we cannot 
say whether the flowering plants ha*e had a polyphyletic or a 
monophyletic origin. Until investigations have supplied the 
necessary data, the complete story of the origin and develop- 
ment of flowering plants and the proposal of a thoroughly con- 
sistent phylogenetic classification will remain impossible. Even 
if the arrangement utilized in this book is found to be all wrons 
in future years it will, nevertheless, have served a most valuable 
purpose in this twentieth century if it leads groping students to 
obtain even a birdseye view of a more or less orderly system in 
the great world of flowering plants which must certainly appear 
as a heterogeneous conglomeration of unrelated things to the 
uninitiated. 

The book is intended for students who have had an introduc- 
tion to general botany, but it is thought that it will be thoroughly 
understood by anyone else who is willing to take it up studiously 
and in its entirety. 

I have endeavored to play up the family as the group that may 
be used more effectively in classification and in an attempt to 
present some of the more clearly demonstrated cases of relation- 
ship. The outstanding feature of the treatment of the families 
is seen in the use of new types of graphic formulae and charts to 
depict floral anatomy and evolution. This method is compara- 
tively new in published form, but it has been used in our classes 
at Nebraska for twenty-eight years, the plan in general having 
been originated by Clements, in 1900. A similar plan was 
published in brief form by the same author in 1908, and 1912, 
and again in 1913; by Bergman in 1917; and by F. E. and E. S. 
Clements in 1927 and 1928 in, Flower Families and Ancestors 
and in Flowers of Coast and Sierra.* The only use of this form 
of chart in a regular textbook to date is in General Botany by 
Holman and Robbins, 1927, where a brief reference is made to it. 

The formula method of depicting prominent features of families 



PRE&&QE TO THE FIRST EDITION xiii 

fcp? 

and the grouping of the families on our chart in, accordance with 
the general plan known here as the "Besseyan system" have 
been of inestimable value in the presentation of this great group 
of plants to students and others. The chart presented must be 
viewed in the light of a relatively simple production (although 
considerably more extensive than any yet published) but the 
author trusts that it is sufficient, nevertheless, to suggest almost 
limitless possibilities to the interested teacher and student. 

The author of a book of this sort is largely dependent upon 
works of a more or less similar sort that have already appeared. 
Certain of these sources arc really classic throughout the world, 
such for instance as the following great works: Engler, Die 
Naturlichen Pflanzenfamilien; Wettstein, Handbuch der Sys- 
tematischen Botanik (3d Ed., 1924); LeMaout and Decaisne, 
A General System of Botany, the valuable English edition by 
Hooker; Baillon, Histoire des Plajites, with the English edition, 
The Natural History of Plants, by Hartog; Lindley, The Vege- 
table Kingdom; Bentham and Hooker, Genera Plantarum; and 
A. de Caiidollc, Prodromus systematis naturalis regni vegetabilis. 
Many other publications have contributed values that are deeply 
appreciated. Among these I would mention the following: 
Bentham, Illustrated Handbook of British Flora; Kerner, Pflanzen- 
leben, and tho English edition of this work, Natural History 
of Plants, published by Blackic & Son Ltd., and Henry Holt 
& Company; Rendle, The Classification of Flowering Plants; 
Hutchinson, The Families of Flowering Plants; Bailey, Manual 
of Cultivated Plants; Sargent, Plants and their Uses; Chase, 
First Book of Grasses; Hitchcock, A Textbook of Grasses; and 
numerous manuals, floras, and monographs that can not be 
enumerated here. I have drawn freely upon these and have made 
proper acknowledgment of the same in the usual manner. 

Nearly all of the illustrations in the book have been prepared 
under my direction by that master botanical artist and drafts- 
man, Mr. F. Schuyler Mathews. He has redrawn and adapted 
many figures for our use from numerous sources, but especially 
from the classic works of LeMaout and Decaisne, and Baillon. 
A few figures have been redrawn by special permission from 
Gager, General Botany, and Robbins, Botany of Crop Plants, 
published by P. Blakiston's Sons Co.; Warming-Potter, A 
Handbook of Systematic Botany, published by The Macmillari 
Company; Mathews, Field Book of American Wild Flowers, 



xiv PREFACE TO THE FIRST EDITION 

by G. P. Putnam's Sons, and from Kerner, Natural History of 
Plants, by Henry Holt and Blackie & Son Ltd. A few of the 
figures have been made from original drawings which Mr. 
Mathews has graciously placed at my disposal. This book would 
be a poor thing indeed and, I fear, utterly lacking in appeal in the 
absence of the hundreds of figures that have been reproduced 
from pen-and-ink drawings by the skillful hand of Mr. Mathews. 
Prof. T. J. Fitzpatrick assisted with the proof sheets. 



RAYMOND J. POOL. 



LINCOLN, NEBRASKA, 
October, 1929. 



CONTENTS 

PAGE 

PRKFU-E TO THE SECOND EDITION ix 

PRKFU'E TO THE FlUKT EDITION XI 

CHAPTER 1 

INTRODUCTION . . 1 

Form, Mode of Life, Distribution of Flowering Plants 1 

Value of Flowering Plants 2 

The Flower 2 

Anatomy of the Flower 3 

The Essential Organs 4 

The Flower as a Working Unit 6 

Variations of Flowers 6 

Complete Flowers 6 

Incomplete Flowers 6 

Fruits and Seeds 8 

Relation of Flowers to Fruits and Seeds 8 

Fertilisation in Flowers 8 

Foimation ot Fruits and Seeds 9 

The End of the Cyele 9 

CHAPTER II 

STIUJCTURE OF THE FLOWER 11 

Perigvnous, Hvpogynous, Epigynous Flowers 12 

The Regular Elements of the Flower 14 

Regular and Irregular Flowers 15 

Zygomorphy and Pollination 16 

Stamens 16 

Pollen and Pollen Grains 18 

The Pistil 19 

Ovary and Ovules 20 

Incomplete Flowers 23 

The Flowers of Composites 24 

CHAPTER III 

THE WORK OF THE FLOWER 26 

Significance of Reproduction 26 

Pollination 27 

Pollinating Agents 32 

Structure of Ovules 39 
Fertilization of the Egg . 40 

Maturation of the Seed 41 

xv 



xvi CONTENTS 

PAGE 

CHAPTER IV 

FRUITS AND SEEDS ... 42 

Types of Fruits . 44 

Dry Fruits . 45 

Fleshy Fruits. ... 49 

Tabular Summary of Fruits . . 54 

Seeds ....... .55 

Physical Features of Seeds . 55 

Foods and Other Materials in Seeds . 59 

Behavior of Seeds ... 61 

CHAPTER V 

How FLOWERING PLANTS TRAVEL. . 62 

Nature of Plant Migration. . 62 
Factors in Migration . . .63 

Modifications of the Plant. . 66 

Velocity of Migration 72 

CHAPTER VI 

FORMS AND RELATIONSHIPS IN FLOWERS . 73 

Primitive Flowers and Derived Flowers . 73 

The Number of Floral Parts 78 

The Union of Flower Parts 79 

Indications of Relationships . 81 

Actinomorphy and Zygomorphy 83 

Hypogyny and Epigyny 86 

CHAPTER VII 

FLORAL DIAGRAMS AND FORMULAE . 88 

The Method of Floral Diagrams . 88 

The Method of Floral Formulae . . 93 

Floral "Elements" and Floral "Compounds" . 94 

Formulae Contrast Essential Differences. . 97 

Formulae to Show Zygomorphy . 98 

CHAPTER VIII 

FLOWER CLUSTERS . ... 104 

Single Flowers and Clusters of Flowers 104 

The Kinds of Inflorescences . . .105 

The Racemose Type 105 

The Cymose Type 109 

Compound Inflorescences . .110 

Sterile Flowers, Bracts, etc 111 

CHAPTER IX 

VEGETATIVE CHARACTERISTICS OP FLOWERING PLANTS 114 

Roots. .... ... 115 

Kinds of Roots 116 



CONTENTS xvii 

PAGE 

Root Systems 117 

Stems . 119 

Kinds of Steins .... .120 

Special Features of Sterns 123 

Leaves .... 125 

Typical Leaves . . 120 

Arrangement of Leaves . 126 

Vernation 127 

Venation 128 

Simple and Compound Leaves . 128 

The Outline of the Leaf . . 130 

Variations in the Surface? of Leaves 134 

Special Kinds of Leaves . . 135 

CHAPTER X 

THE CLASSIFICATION OF PLANTS 137 

Taxonomy . 137 

The Basis of Classification for Plants 138 

Natural arid Artificial Systems 139 

The Common Groups 140 

The Species Concept . 140 

The Genus Concept . 141 

Families, Orders, Classes 142 

Plant Relationship and Nomenclature. 144 

Origin and Nature of Names of Plants 145 

Nomenclatorial Practices 146 

CHAPTER XI 

PRINCIPLES OF CLASSIFICATION OF FLOWERING PL\NTS 149 

The Question of Origin .... 149 

The Bennettitales . 150 

Woody and Herbaceous Types . . 150 

Bessoy's Principles . . 151 

Vegetative Anatomy ... 151 

Floral Anatomy 152 

The Outline Shown by the Chart 156 

Construction of the Chart 156 

Extent of the Chart 157 

Symbols used on the Chart 159 

The Nature and Use of Analytical Keys 160 

Keys and Synopses .... 160 

Types of Keys 161 

Manuals and Floras .165 

CHAPTER XII 
SELECTED ORDERS AND FAMILIES OF DICOTYLEDONS. . .... 167 

Vegetative Nature of Dicotyledons 167 

Growth and Length of Life. . ... -67 



xviii CONTENTS 

PAGE 

Floral Pattern in Dicotyledons 168 

Order Ranales, the Buttercup Order 168 

The Magnolia Family 169 

The Papaw Family 170 

The Nutmeg Family 171 

The Laurel Family 171 

The Barberry Family 172 

The Buttercup Family 174 

The Waterhly Family 175 

The Pepper Family 177 

CHAPTER Xril 

THE MALLOWS AND GERANIUMS . 179 

Order Malvales, the Mallow Order 179 

The Mallow Family 179 

The Linden Family 181 

The Cacao Family 1S2 

The Kim Family 183 

The Mulberry Family 1 8 1 

The Nettle Family 186 

Order Geraniales, the Geranium Order 186 

The Geranium Family 187 

The Oxalis Family 188 

The Flax Family 189 

The Orange Family 190 

The Balsam Family . 191 

The Spurge Family 192 

CHAPTER XIV 

THE TEAS, POPPIES, and PINKS . 195 

Order Theales, the Tea Order . 195 

The Tea Family 195 

The Garcima Family 196 

The Violet Family 197 

The Passion Flower Family 198 

The Papaya Family 198 

Order Papaverales, the Poppy Order 199 

The Poppy Family . . 199 

The Caper Family 200 

The Mustard Family 201 

The Mignonette Family . . 203 

Order Caryophyllales, the Pink Order . 203 

The Pink Family . ... 204 

The Purslane Family 205 

The Gooset'oot Family . 205 

The Amaranth Family. . 206 

The Buckwheat Family . 207 



CONTENTS xix 

PAGE 

The Four-o'clock Family 208 
The Willow Family . . . 209 

CHAPTER XV 

THE PRIMROSES, HEATHERS, AND EBONIES 211 

Order Primulales, the Primrose Order 211 

The Primrose Family 211 

The Plantain Family 212 

The Leadvvort Family 213 

Order Encales, the Heather Order 214 

The Heather Family 214 

Order Ehenales, the Ebony Order 215 

The Ebony Family 215 

CHAPTER XVI 

THE GENTIANS, PHLOXES, SNAPDRAGONS, AND MINTS 217 

Order Gentianales, the Gentian Order 217 

The Gentian Family 217 

The Olive Family 218 

The Dogbane Fainilv 219 

The Milkweed Family 220 

Order Polemomales, the Phlox Order 221 

The Phlox Family 221 

The Morning-glorv Family 222 

The Waterleaf Family ' 223 

The Nightshade Family 223 

The Forget-me-not Family 224 

Order Scrophulanales, the Snapdragon Order 225 

The Snapdragon Family 226 

The Bignoma Family 226 

The Broomrape Family 227 

The Acanthus Family 228 

The Bladderwort Family 229 

Order Lamiales, the Mint Order 229 

The Verbena Family 230 

The Mint Family 230 

CHAPTER XVII 

BUTTERCUPS TO ASTERS 232 

Order Rosales, the Rose Order 232 

The Rose Family 233 

The Senna Family 234 

The Mimosa Family 235 

The Bean Family 235 

The Saxifrage Family . 237 

The Hydrangea Family 238 

The Gooseberry Family 239 

The Witchhazel Family . 240 



xx CONTENTS 

PAGE 

The Sycamore Family. ... 241 

The Stonecrop Family 242 

CHAPTER XVIII 

THE MYRTLES, STARFLOWERS, AND CACTUSES 243 

Order Myrtales, the Myrtle Order . 243 

The Myrtle Family ... 243 

The Pomegranate Family 244 

The Mangrove Family 245 

The Evening Primrose Family 246 

The Loosestrife Family 248 

Order Loasales, the Starflower Order 249 

The Loasa Family 249 

The Begonia Family 249 

The Pumpkin Family . 250 

Order Cactales, the Cactus Order. . 252 

The Cactus Family 252 

CHAPTER XIX 

THE BITTERSWEETS, MAPLES, and PARSLEYS 254 

Order Celastrales, the Bittersweet Order 254 

The Bittersweet Family . . 254 

The Grape Family . 255 

The Buckthorn Family . . . 256 

The Holly Family. . . .257 

The Oleaster Family . . 258 

The Mistletoe Family. . . . 259 

Order Sapindales, the Maple Order 260 

The Soapberry Family. 260 

The Maple Family . 261 

The Cashew Family 262 

The Walnut Family . 263 

The Oak Family . 264 

The Birch Family. . 265 

Order Umbellales, the Parsley Order 266 

The Ginseng Family 266 

The Dogwood Family. . 267 

The Parsley Family. 268 

CHAPTER XX 

THE MADDERS, BLUEBELLS, AND ASTERS . . 270 

Order Rubiales, the Madder Order . 270 

The Madder Family. . .270 

The Honeysuckle Family . .271 

The Valerian Family . . . . 272 

The Teasel Family . . . 273 

Order Campanulales, the Bluebell Order ... . 274 

The Bellflower Family 274 



CONTENTS xxi 

PAGE 

Order Asterales, the Aster Order . 275 

The Composite Family . . 276 

Key to the Tribes of Composites ... . 279 

CHAPTER XXI 

SELECTED ORDERS AND FAMILIES OF MONOCOTYLEDONS . . 284 

The Monocotyledon Series. . . . 284 

The Flowers of Monocotyledons 285 

Hypogynous Monocotyledons . 286 

Order Alismales, the Water Plantain Order. . 286 

The Water Plantain Family . 286 

The Arrowgrass Family . . 287 

The Pondweed Family. 288 

The Bur Reed Family. 288 

The Cattail Family. . . 289 

The Screw-pine Family . 290 

CHAPTER XXII 

THE LILIES, PALMS, AND AROIDS 291 

Order Liliales, the Lily Order 291 

The Lily Family 291 

The Spiderwort Family . 292 

The Pickerel Weed Family . 293 

The'Rush Family. 294 

The Pipewort Family ... 295 

Order Arales, the Arum Order . 295 

The Arum Family . 296 

Order Palmales, the Palm Order 297 

The Palm Family 297 

CHAPTER XXI 1 1 

THE GRASSES AND SEDGES ..... . 299 

Order Graminales, The Grasses and Sedges 299 

The Sedge Family . . 299 

The Grass Family . . 300 

Key to the Tribes of Grasses . . . 303 

CHAPTER XXIV 

THE WATER WEEDS, IRISES, AND ORCHIDS. . . 309 

Order Hydrales, The Water Weed Order. . . .309 

The Tapegrass Family. . . . . 309 

Order Jridales, The Iris Order . . 310 

The Amaryllis Family. . ... , 310 

The Iris Family .... .... 312 

The Pineapple Family. ... . .313 

The Banana Family 313 

The Ginger Family 315 



xxii CONTENTS 

PAOK 

Order Orchidales, The Orchid Order. . 315 

The Orchid Family ... . . . 316 

CHAPTER XXV 

A BIT OF EARLY HISTORY . . .318 

Work of the Ancients . 318 

The Time of the Herbals 319 

Dawn of Binomial Nomenclature 321 

The Foundation of Modern Botany 322 

Linnaeus and His Work . 324 

The System Proposed by Linnaeus 325 

Value of the Work of Linnaeus . 328 

CHAPTER XXVI 

FROM LINNAEUS TO ENOLER AND BESSEY 329 

The Natural System Founded . . .329 

Contributions of B. and A. L. de Jussieu 329 

Influence of de Candollo . 331 

de Candolle's System 332 

Work in England 333 

Endlicher's System ... . 334 

The Classic System of Bentham and Hooker . 335 

Eichler's System 338 

A Notable System by Engler . 340 

Outline of Engler's System . 341 

Influence of European System:; . 345 

Classification in America. . . .316 

Earlier Proposals by Bessey . . 346 

The Besseyan System in Final Form 348 

CHAPTER XXVII 

COLLECTING AND PREPARING SPECIMENS . 354 

Equipment for Collecting . 354 

Selection of Specimens . 358 

A Practical Plant Press . . 360 

Fillers for the Press . 362 

Temporary Labels . . 364 

Preparing The Specimens for the Herbarium 367 

Permanent Labels . . 368 

Filing the Specimens .... . 369 

Subsequent Care . 369 

CHAPTER XXVIII 

REFERENCE BOOKS, MONOGRAPHS, MANUALS, AND FLORAS . . 370 

Works of Broad Scope . . . . . 370 
General Manuals and Cyclopedias of Wide Use. . . . . 371 

Regional Manuals and Floras. . 372 

Regional, State, and Local Floras, Including More or Less Popular 

Treatises . . .... 373 



CONTENTS xxiii 

PAGE 

Manuals for Trees, Tree Books . 376 

Popular Works on Flowers 378 

Books on Cultivated Plants 379 

Books on Grasses 380 

Valuable Works Published since the First Edition of This Book 381 

GLOSSARY . . 385 

INDEX .... . . 397 



ANJ) 

TLA NTS 



CHAPTER I 
INTRODUCTION 

The Angiosperms or flowering plants are at once the most 
varied, useful, and numerous of all of the major groups into which 
the vegetable kingdom is commonly divided. At least 150,000 
species of flowering plants have been described. New species are 
being added each year by the extended survey of the vegetation 
of the earth and by a more critical examination of the older 
materials. They are very evidently a rapidly expanding or 
evolving group. They dominate the world of plants today. 
Such facts reflect the success that has attended flowering plants 
in their long struggle for existence under the manifold variations 
of terrestrial and aquatic environments. 

To this vast array of organisms must also be added thousands 
of varieties, races, strains, etc. of flowering plants that have been 
brought into being largely through the efforts of man. These 
owe not only their origin but also their perpetuation largely to 
man and to the care he has bestowed upon them. These are 
really much-coddled forms. When man's guiding genius is 
relinquished they are likely to "revert" to inferior or worthless 
forms. 

Form, Mode of Life Distribution. Flowering plants exhibit 
a great variety of form and mode of life. Some of them are 
minute disks of very simple construction floating on the water. 
Others are gigantic trees, 300 feet or more tall and with a body 
structure and life history rivaling those of higher animals in 
complexity. Some of them live for a few brief weeks, but 
centuries are spanned by the activities of others. They are seen 
at the seashore, on the very tops of high mountains, and in the 

1 



2 FLOWERS AND FLOWERING PLANTS 

withering heat of vast deserts. They are conspicuous in the 
tangled luxuriance of equatorial forests, and others are scattered 
over the frozen soil and among the glaciers and snow fields in 
the Arctic and Antarctic regions. They are typically supplied 
with chlorophyll, so they are independent organisms, but numer- 
ous species have become degenerate parasites or saprophytes 
living the life of a mildew or toadstool in so far as nutrition is 
concerned. Some of them have even developed structures by 
which they may entrap and partially devour insects and other 
small creatures. This is indeed a curious and interesting feature 
of certain flowering plants^but the carnivorous habit in plants 
is probably more interesting than significant. 

Vftjiiff nf THnwp.riVig Plants. Flowering plants are very largely 
responsible for the maintenance of all other living things on earth, 
and yet hundreds of them are of the nature of worthless weeds 
or for other reasons are undesirable. They contribute foods in 
enormous quantities and of great variety for the millions of 
creatures comprising the animal kingdom, including man. They 
produce hiding places for the animals of the wilds and they con- 
tribute a multitude of materials that seem to be necessary for 
the happy homes of men. 

THE FLOWER. 

The outstanding structure in the life history of flowering 
plants is the flower (Fig. 1). The flower and the structures that 
are developed because of its presence are the features that stamp 
these organisms as unique and as quite different from all other 
plants known. They all produce flowers of some sort, although 
these might not be recognized as flowers in every case by the 
man in the street. And some of them produce structures that are 
strikingly flower-like to the uninitiated but that are not flowers at 
all in the point of view of the botanist or in the economy of the 
plant. Thus some of the first things to be learned in the study of 
flowering plants have to do with the flower as the most distinctive 
element of their structure and behavior. 

Dftfinjfion nf th* TTinwor it is quite impossible to define a 
flower briefly and tersely. Flowers are too complex and too 
variable in structure and behavior to permit of strict definition 
or even of very brief description. The chief physiological sig- 
nificance of the flower is seen in the fact that it is the principal 
seat of reproduction in flowering plants. It is effectively con- 



INTRODUCTION 



structed to insure fertilization of the eggs which it produces, 
and so it may be stated that the flower is the organ or combina- 
tion of organs (Fig. 1) of the plant that makes sexual reproduc- 
tion possible. The flower is, in a very definite sense, a sex 
organ or a collection of sex organs placed in relationships that 
are distinctive of flowering 
plants. 

The reproductive signif- 
icance of flowers must be 
clearly sensed if one is to 
comprehend the many vari- 
eties of form, color, odor, size, 
etc. of flowers, that are among 
the striking characteristics of 
this group of plants, because 
these details are usually inti- 
mately associated with the 
phenomenon of sexual repro- 
duction as it occurs within the 
flower. These plants have 
developed a great many dif- 
ferent kinds or types of flowers 
which differ much in detail, 
but they all agree in that their 
primary role is to produce 
fruits and seeds. Their success in caring for this great work has 
been the astounding contribution of the group, as can be demon- 
strated by a few observations in almost any community. 

ANATOMY OF THE FLOWER 




FIG. 1. The gross anatomy of a typical 
flower. A, vertical section of a flower 
showing sepals, petals, stamens, arid pistil 
grouped symmetrically upon the axis; B, 
the pistil with all other parts removed, 
showing ovary, style, and stigma; C, 
transverse section of five united carpels 
(pistils) ; Z), a symmetrical flower viewed 
from the front; E, one sepal (to the left) 
and one petal (to the right) ; F, a single 
stamen showing filament and anther. 



The flower is, anatomically, a highly modified and special- 
ized stem or branch of a stem bearing appendages (Fig. 1). 
This is readily noted if a very young flower is examined 
before the various parts have opened. The pedicel or flower 
stalk is very evidently a branch of the main body or stem system 
of the plant. At the distal end of the pedicel is a structure 
closely resembling a common bud. The outer leaves or scales 
are commonly green, but they may be of almost any color. Like 
the scales of an ordinary bud, these leaves protect the delicate 
structure within the flower. These outermost leaves or scales 
of the flower are known collectively as the "_calyx"_ (Fig. 1, A, 



FLOWERS AND FLOWERING PLANTS 



D and E). Each scale is called a "sepal," i.e. the calyx is 
composed of sepals. Another set of leaves (Fig. 1, A and D) is 
disclosed when the flower (or bud) opens, and these are particularly 
noticeable because they are commonly white or brightly colored. 
These lie just within the calyx (Fig. 1, A and D) as a rule and 
they alternate with the sepals. The modified leaves of this 
second and inner series are commonly known as "petals," and 
the collection of petals, is called the "corolla" (Fig. 1, A, D and E). 
The calyx and corolla together constitute the ftoral envelove or 
the perianth which is an important part of the flower because 





C 

FIG. 2. FIG 3. 

FIG. 2. Stamens and staminate flowers. A, a single stamen of onion, Allium, 
/?, stamens of wallflower, Erysimum; C, staminate or male flower of boxelder, 
Acer negundo; D, a single stamen of blueberry, Vaccinium (after Le M. and Dec.). 

FIG. 3.- Incomplete flowers. A, the pistillate or female flower of willow, 
Salix; B, the staminate or male flower of willow; C, the staminate flower of 
oak, Quercus; D, the pistillate flower of oak (after Le M. and Dec.). 

of the protection it affords to the delicate sex organs that lie 
in the interior. The perianth is usually the showy part of the 
flower also, either on account of its color or shape, or both. 
It plays a very important role in connection with pollination, 
fertilization, and seed production as will be noted in greater 
detail in a later chapter. The sepals and petals may be referred 
to as the jg^c6^or_or^aM_of the flower (Fig 1). 

ential Organs. As the dissection of the flower is con- 
tinued another set of very different appendages is found attached 
to the pedicel inside the corolla. These are the stamens (Figs. 1, 
F; 2 and 3) and they are essentially the male sex organs. The 
stamens may be very numerous or in some flowers there may be 



INTRODUCTION 5 

but few of them. Each stamen is composed of a slender stalk 
or filament at the top of which is a lobed, bag-like anther which 
produces the pollen grains (Fig. 13) in which the male germ cells 
eventually arise. Pollen grains collectively are commonly 
known as pollen. The anthers are commonly yellow and each 
anther may produce a great many pollen grains which are liber- 
ated when slits or pores are formed in the anthers. Each pollen 
grain usually pdnrp tiW9 male ftametes or sex cells, the genera- 
tfJYfi f^kg Thousands and even millions of pollen grains are 
produced in the flowers of certain plants. 

The Pistil. The fourth floral organ is the pistil or carpel 
(Fig. 1, B and C), which usually stands in the very center of the 
flower and is, therefore, surrounded by the stamens, petals, and 




FIG. 4. -Forms of pistils. A, The pistil of tobacco, Nicotiana; /?, of walnut, 
Juglans; C, of wheat, Triticum (after Le M. and Dec.), D. of a pink, Spergiilana 
(after Mathpwx). 

sepals. The pistil is usually distinctly different from any of the 
other parts of the flower. It is more or less flask-shaped or 
pitcher-shaped, with a bulbous base (Fig. 4, A and D) and a 
more or less elongated stalk leading upward. The enlarged 
base is called the "ovary" (Fig. 1, B\ Fig. 4) and the stalk leading 
from the ovary is called the "style." The tip of the style is often 
glandular and it is called the "stigma." The stigma is fre- 
quently more or less expanded into a bulb or disk, or cut into 
two, three, or more slender segments. There is a well-developed 
cavity in the ovary of the pistil and in this cavity one to many 
ovules are produced. The ovules are usually attached to the 
central axis of the ovary (Fig. 1, C) or to the inner wall. Each 
ovule usually contains an egg, the female gamete or sex cell. 



6 FLOWERS AND FLOWERING PLANTS 

_ Ovary, Fruit and Seed,. The ovary may be simple or compound. 
A simple ovary is composed of a single carpel or pistil. A com- 
pound ovary is composed of two or more carpels (Fig. 1, C) or 
pistils grown together more or less firmly. Jn compound pistils 
the styles are usually united also, sometimes even to the very 
tip of the stigma. A simple pistil or each cell (carpel) of a com- 
pound pistil (Fig. 4, D) may contain a single ovule or many ovules. 
The pistil (ovary) normally develops into a fruit and each ovule 
develops into a seed. 

TJifi Fln\yfT fl c fl Working Unit. So much for the four regular 
parts of a complete flower, sepals, petals, stamens, pistils. The 
interplay of these parts in connection with the work of the flower 
as a whole may now be summarized briefly. A fine illustration of 
the biological principle known as the division of labor is found 
herein. The sepals (calyx) are commonly more or less green 
anqi so they are able to supplement the regular supply of food 
coming to the flower from the stem, at the same time that they afford 
protection for the flower. The corolla with its variety of colors, 
color patterns, form, and size in different flowers is particularly 
valuable in attracting insects and other pollinating animals as 
well as affording considerable protection. The stamens produce 
the sperms or male sex cells, and the ovules, inside the ovary of the 
pistil, produce the eggs or female sex cells. The sepals and 
petals are useful accessory organs, but the stamens and pistils are 
essential organs, 

VARIATIONS OF FLOWERS 

.Complete Flowers. The flowers of most species of flowering 
plants possess both stamens and pistils, and also petals and sepals. 
Such flowers may be termed " complete" flowers (Fig. 5) since 
they have all four of the regular appendages that are charac- 
teristic of flowers. Violets, geraniums, primroses, heathers, 
bluebells, snapdragons, roses, honeysuckles, lilies, irises, and 
orchids are representative of groups in which complete flowers 
are very common. 

Incomplete Flowers. Many different species of flowering 
plants produce flowers that lack one or more of the four regular 
parts. For instance, certain flowering plants are known which 
do not have petals or sepals, as is shown by some buttercups, 
buckwheats, willows, cottonwoods, hickories, grasses, cattails 



INTKODUCriON 7 

(Fig. 3). In a goodly number of groups there are species in 
which sepals and petals are lacking but the stamens and pistils 
are present. These flowers may be called " incomplete ' * but 
"perfefft." since they still possess the essential organs, the stamens 
and pistils. In others the stamens and pistils are produced in 
totally separate flowers upon the same individual plant (Fig. 3). 
This is the case in some members of the buckwheat family, in 
certain grasses (as maize, wild rice, etc.), cattails, arrowheads, 
grapes, hickories, walnuts, chestnuts, oaks, etc. There are 
still other flowering plants in which the staminate and pistillate 
flowers are formed on totally separate individuals of the species, 
as in the poplars (cottonwoods, aspens, etc.), willow, ash, hemp, 




FIG. 5. Different kinds of flowers. A, a regular flower with four sepals and 
petals and six stamens as in a mustard, Cochlearia; B t spiderwort, Tradescantia; 
C, honeysuckle, Lonicera; D, clover, Trifolium; E. rose mallow, Hibiscus (after 
Le M. and Dec.). 



mulberry, certain maples, Ailanthus, etc. (Figs. 2C; 3 A and C). 
The situation in these latter cases is much like that in the higher 
animals in which the individuals are strictly differentiated on a 
sexual basis, i.e., they are males or females. Thus in cotton- 
woods some trees are staminate or male only, and others are 
pistillate or female only. This condition is more common among 
flowering plants than is popularly known, and it explains why 
every individual plant in certain species does not produce fruits 
and seeds. Obviously, an individual plant which develops sta- 
mens only, and is therefore exclusively male, is quite incapable 
of producing fruits and seeds. Some flowering plants produce 
both perfect and imperfect flowers and various other combina- 
tions all on the same individual. 



FLOWERS AND FLOWERING PLANTS 



Relation of Flowers to Fruits and Seeds. Pistillate or female 
flowers are as a rule necessary in every individual flowering plant 
that produces seeds. Thus, care should always be exercised in 
selecting plants if certain desirable features involve the pres- 
ence of pistillate flowers and the products of their behavior. 
A friend once complained of the failure of the bittersweet plants 
which he had moved from the woods to his back lawn to pro- 
duce the beautiful, well-known scarlet berries in the autumn. 
Examination disclosed the fact that the plants in question were 
exclusively staminate or male and so could not be expected to 
fruit. The experience taught the friend a simple lesson in the 
biology of flowering plants. 

PollipftfiQn. -The transfer of pollen grains produced by the 
.stamens of flowers to the stigmas of the pistils is known as 
"pollination.". The pollen (Fig. 13) is ripe and ready to be 
scattered about the time the flower buds open, but the movement 
is not greatly affected by any power which the plant possesses. 
Whether the transfer is through short distances, as it usually is 
not, or through comparatively long intervals, as it usually is, the 
two most prominent external agencies in pollination are^ inland 
insects^. Only in a few cases is the stigma of a given flower 
pollinated by the pollen from that same flower. As a matter of 
fact, such self-pollination is usually prevented because the pollen 
is distributed before or after the stigma is ready to receive it, 
and in other ways self-pollination and self-fertilization are 
prevented. There are many other types of flower behavior that 
serve to render self-pollination relatively impossible. A com- 
paratively few cases are known of perfect flowers in which the 
stigma and stamens lie in contact with each other so that self- 
pollination may occur before the flower opens. 

in Flowers. The union of a male sex cell or 



sperm produced by a pollen grain with the female sex cell_or egg 
j3rodujced_ inside anj) vule within the ovary is commonly called 
^^rtilizatipn^" (Figs. 25 and 26). This is usually made possible 
in flowering plants by the growth of a long, slender protuberance, 
known as the "pollen tube" and produced by the individual 
pollen grain, which grows through the soft, juicy tissue of the 
stigma and style, by which the sperm cells are carried into the 
ovule and discharged near the egg. Fertilization is the crowning 
achievement of the flower since in this act a potentially new 



INTRODUCTION 



9 



individual arises, which under normal conditions may develop 
into a mature plant of the same kind that produced it. 

Formation of Fruits 'and Seeds, Soon after fertilization has 
been accomplished, the flower parts surrounding the ovary tend 
to collapse, wither, dry out, and fall away. The stamens, 
petals, and sepals disappear rather soon, and the style and stigma 
of the pistil are either shed or become more or less completely 
lost in the transformation of the pistil into the fruit (Figs. 6 and 
7). The ovules, inside which the eggs have been fertilized, are 

promptly transformed into 
seeds (Figs. 35 and 36) as the 
fruit ripens. The fruit at ma- 
turity is essentially a trans- 





FIG. 6. FIG. 7. 

FIG. 6. Typos of dry fruits. A, capsule of autumnal lily, Colchicum; B, 
transverse section of the same; C, tailed achene of anemone, Anemone; D, 
simple achene of buttercup, Ranunculus; E, silique of mustard, Bra^sica 
(after Le M. and Dec.) 

FIG. 7. Fleshy fruits. A, cluster of berries of currant, Ribes; B, two drupes 
of cherry, Primus (after Mathews). 

formed ovary, inside of which there are one or more seeds each of 
which contains a miniature plant or embryo of the next generation. 
This embryo is commonly surrounded by or filled with an abun- 
dance of food which greatly enhances its chances for later develop- 
ment or germination. The seed as it is shed from the plant in 
this stage has much in common with the fertilized avian egg as it 
is discharged from the body of the mother bird. Each has a 
more or less firm covering composed of one or two layers of 
resistent tissues or material, and inside of each is a living embryo 
with an abundant supply of food. This essential similarity is 
further reflected in the fact that the two structures are among the 
most common objects that supply food for man and beast. 

The End of the Cycle. The production of fruit and seed ter- 
minates the cycle in so far as the individual flower or crop of 



10 FLOWERS AND FLOWERING PLANTS 

flowers are concerned. The plant may continue to produce 
succeeding generations of flowers and seeds just as long as environ- 
mental conditions outside the plant make'lsuch activities possible 
or until disease due to any one or a combination of causes so 
weakens the plant that it no longe^. can supply the material and 
the energy necessarily required Jbr such vitally important proc- 
esses. Degeneration then overtakes the plant and it is likely 
either to succumb rather rapidly or to linger for years as a pitiable, 
crippled, worthless, and more or less unrecognizable image of 
its former beauty. 



CHAPTER II 

**v 

STRUCTURE () THE FLOWER 

It has been noted that a flower is a more or less highly differen- 
tiated and specialized branch of the stem system in the flowering 
plants. This modified branch becomes transformed into hun- 
dreds of different types *6f flowers. The distal end or apex of 
the floral branch upon which the regular organs that constitute 
the important features of the flower are developed is termed the 
" receptacle " or "torus." Ordinarily this is merely a more or 
less thickened, expanded or hollowed-out tip of the branch. 
There is often a more or less leaf-like appendage at the base of 
the pedicel of the flower known as the "floral bract." 




FKJ. 8 Flowers to show various types of axis and placement of perianth. 
A, vertical section of a flower of mousetail, Myosvrus minimus, showing a slender, 
spire-like axis and many separate carpels (after BaiUon) ; B, a flower of buttercup, 
Ranunculus, with the spirally arranged carpels on a cone-like axis (after Baillori); 
C, vertical section of a flower of raspberry, Rubun, with its dome-like central 
axis and spreading disk-like axis, and many separate stamens and carpels (after 
Le M. and Dec ); D, vertical section of a buttercup flower (after Le M . and Dec.); 
E, vertical section of bridal wreath, Spiraea, flower showing deepening of the 
axis and reduction in number of carpels (after Baillon); F, vertical section of 
flower of rose, Rosa, showing further deepening of the axis until it has becojpae 
urn-like (after Baillon). *^ 

Form of the Receptacle. In the buttercup, magnolia, and the 
tulip tree the receptacle is more or less dome-shaped, conical or 
spire-like (Fig. 8). The stamens, petals, and sepals are attached 
near the base of this receptacle, and the carpels are arranged 

11 



12 FLOWERS AND FLOWERING PLANT** 

spirally over the upper portions of the same receptacle. This 
type of flower is called a "hypogynous" flower. The central 
part of the receptacle of the strawberr&Hower is of this nature 
(Fig. 8) and after fertilization it becomes greatly enlarged, very 
juicy, usually bright red, and, in short, is transformed into the 
" fruit " or edible part (Fig. 32, C)*of that plant. The blackberry 
and the raspberry (Figs. 8 and 32, B) produce the same type 
of torus but it is not excessively developed in either. The torus 
becomes a portion of the edible structure in the blackberry, 
dewberry, and the loganberry; but in most varieties of rasp- 
berries it remains on the stem as the " berries "are picked. In 
the roses (Fig. 8, E and F) and their kin and in the evening 
primroses and various other types the receptacle or torus becomes 
disk-like, cup-shaped, pitcher-shaped, or even tubular (Fig. 136) 
and it bears the sepals, petals, and stamens arranged cyclically 
on the upper or outer rim. This type of torus or axis has been 
developed by a deepening and hollowing of an axis which was 
disk-like or possibly even conical in the beginning. The axis of 
the strawberry flower shows what is in reality a combination 
of the cone type and the disk type of torus in which the former 
becomes impressively dominant as the fruit develops. In the 
closely related bridal wreath (Fig. 8, E) the disk-like axis is per- 
ceptably hollowed in the center, but in the cherry, plum, peach, 
and almond the torus has become very deeply hollowed until it 
is urn-shaped or almost tubular. 

Perigynous Flowers. The rose or cherry type of flower with 
a deeply hollowed-out torus and with the sepals, petals, and 
stamens on the summit is known as a "perigynous" flower 
(Fig. 8). The pistil or pistils in these flowers are attached to the 
bottom of the cup-shaped torus (Fig. 8 and 9), but this is in reality 
the morphological apex or tip of the general floral axis, so that in 
reality the sepals, petals, and stamens are inserted at a point 
morphologically below the pistil and, hence, the pistil is really 
superior, as in the buttercup. Nevertheless, the distinction is 
fairly easy to note in mature flowers and it constitutes a useful 
feature of such types which has long been used in practical 
classification. 

Hypogynous and Epigynous Flowers. Most flowers are 
hypogynous, i.e., the ovary is superior or it is inserted on the tip 
of the torus (Figs. 8, 102, 112, 113 and 121), but there are many 
flowering plant species in which the ovary is inferior, i.e., the 



STRUCTURE OF THE FLOWER 



13 



flower is epigynous (Figs. 9, 153, 156, 159, 174, 175, and 177). 
Good examples of the latter situation are found in the carrot, 
coffee, honeysuckle, bluebell, sunflower, evening primrose, iris, 
and the orchids. This striking difference has followed the 
deepening of the cup-shaped torus as in the rose (Figs. 8 and 9), 
and the subsequent union of this structure with the ovary so 
that the ovary and the lower portion of the torus appear to be a 
unit structure. Other flower parts may also become united 
with the ovary so that the inferior ovary is not necessarily exclu- 
sively receptacular in every case. In Fuchsia (Fig. 156) and many 
other flowers the union between torus and ovary has not only 




FIG. 9. Examples of perigynous and epigynous flowers as shown by vertical 
sections. A, almond, Amygdalus (after Le M. and Dee.}; B, bluebell, Campanula 
(after Baillori); (7, rose, Rosa (after Le M. and Dec.); Z), coffee, Coffea (after 
Baillori); E, myrtle, Myrtus (after Le M. and Dec.); F, carrot, Daucus (after 
Baillori) . 

been so complete as to produce sfn inferior type of ovary, but the 
axis has also been prolonged into a slender tubular structure 
extending well beyond the upper limit of the ovary which bears 
stamens, petals, and sepals on the rim. These differences in 
the nature and form of the torus coupled with differences in the 
attachment of the other parts of the flower are very helpful 
earmarks in the placement of the species of flowering plants in 
their proper groups. 

The cone-shaped receptacle with superior ovary in hypogynous 
flowers is regarded as a more primitive or " lower" type than the 
cup-shaped receptacle in perigynous flowers. The inferior ovary 
of epigynous flowers is regarded a still higher type in most modern 
systems of classification which pretend to take account of 
possible phylogeny. 



14 FLOWERS AND FLOWERING PLANTS 

THE FOUR REGULAR ELEMENTS OF THE FLOWER 

Sepals, Petals, Stamens, Pistils. The four regular parts of a 
complete flower, sepals, petals, stamens, and pistils are related 
to the torus of the flower and to each other in a very definite 
fashion (Fig. 1). The outermost parts are the sepals and these 
taken together constitute the calyx. The next series, going 
toward the center of the flower, is composed of the petals, known 
collectively as the corolla. Calyx and corolla together constitute 
the perianth and they are commonly more or less leaf -like units 
that differ greatly in size, color, shape, number, and duration. 
The calyx is usually composed of as many sepals as there are 




FIG. 10. Flowers that show various forma of sympetaly and synsepaly. 
A, jimsonweed, Datura (after Le M. and Dec.}; B, jessamine, Jasminum (after 
Le A/, and Dec); C, morning-glory, / porno c a (after Le M. and Dec.), D, lily-of- 
the-valley, Coneallana (after Le M. and Dec.); E, a composite, Bnmoma (after 
Baillon). 

petals in the corolla, but in some groups (purslanes, poppies, 
etc.) there are commonly fewer sepals than petals. The sepals 
are usually green or inconspicuously colored, however in some 
families (buttercups) they are sometimes colored like petals and 
they take the place of petals, but in still others (tulip, Easter 
lily, onion) sepals and petals are colored alike and are scarcely 
distinguishable except by position. The showiness of most 
flowers is usually due to the presence of brightly colored petals, 
but in a number (Clematis, Pasque flower) this quality may be 
due solely to brightly colored sepals that have taken the place of 
the petals. 

Size of Flowers. The size of flowers as represented by the 
spread of the open perianth varies from almost microscopic 



STRUCTURE OF THE FLOWER 15 

in certain grasses and water plants to an enormous structure 
4 or 5 feet in diameter and weighing 15 pounds in certain species 
of Rafflesia parasitic on the roots of grapes in the tropical 
forests of the Malay archipelago. 

Union of Floral Elements. The individual members of both 
calyx and corolla are separate from each other in many flowers. 
Such flowers are said to be "polysepalous " and "polypetalous, " 
respectively (Figs. 8 and 9). In many other flowers the sepals 
appear to be more or loss united to produce a continuous girdle 
(Figs. 9 and 10) about the flower. Such a calyx is termed 
"gamosepalous " or a synsepalous. ;7 The petals appear united 
also to form a more or less tubular or rotate corolla in many 
flowers to produce what is called a "gamopetalous " or "sympetal- 
ous" corolla. The united part is the tube and the spreading 
parts or the lobed border is the limb (Fig. 10). The perianth 
with united parts is commonly regarded as derived or "higher" 
(or later) than the perianth with separate parts. 

Regular and Irregular Flowers. Most flowers are beautifully 
symmetrical, i.e. regular or actinomorphic, because of the radial 
symmetry of their development (Figs. 1, 8, 10 and 113). But 
many flowers are more or less unsymmetrical, irregular, or zygo- 
morphic, i.e., lopsided, because some of the petals on one side* 
of the gamopetalous or polypetalous corolla are larger or they 
have a different shape from the other portion of the flower 
(Figs. 11, 141, 144 and 146). 

The Flowers of Beans. In the beans and their kin (Figs. 11 
and 146) may be seen one of the most familiar types of floral 
irregularity or zygomorphy. The bean (or sweet pea) flower 
is composed of five petals in three distinct sets or groups. The 
large petal in the back or upper part of the flower is the standard 
or banner; in front and usually below is the keel made up of two 
petals; and to the right and left of the keel are the other two 
petals, the wings (Figs. 11, A and 146). The broadly expanded 
standard, the narrow, elongated keel, and the wings beneath 
the standard and more or less clasping the keel, serve to produce 
a very distinctive type of irregular corolla called the "papiliona- 
ceous" corolla. 

The Flowers of Mints. In the mints, the tube of the corolla 
is commonly deeply split into two irregular lobes (Figs. 11 and 
144). The upper lobe is usually erect and is composed of two 
petals, and the lower lobe, composed of three petals, is more or 



16 



FLOWERS AND FLOWERING PLANTS 



less spreading. This is known as a bilabiate, i.e. a two-lipped 
corolla. 

Many other natural families of flowering plants show zygo- 
morphic flowers of great variety of form and color pattern. 
The orchids (Fig. 203) and snapdragons (Figs. 11 and 141) an* 
notable groups in this connection in which form and color servo 
to produce hundreds of curious and complicated types. The 
calyx is sometimes involved in zygomorphy also (Fig. 115), but 
as a rule not to such an extreme degree as in the case of the 
corolla. 




FIG. 11. Flowers that show various types of zygomorphy, sympetaly, and 
position of the ovary. A, pea, Pittum (after Baillon); 1$, bugle, Ajuya (after Le 
M. and Dec.}; C, a mint, Lam mm (after Lc M. and Dec.}, D, speedwell, Veronica 
(after Le M. and Dec.); E, sesame, Setainum (after Le M. and Dec.); F, honey- 
suckle, Lonicera (after Baillon), G, monkshood, Aconitum, partially dissected 
(after BaiUon); //, water plantain, Ahsma, an actinomorphic flower with which 
to compare the others (after Le, M. and Dec.}; 7, snapdragon, Antirrhinum, 
(after Le M. and Dec.); J, valerian, Valenana (after Le M. and Dec.}. 

Zygomorphy and Pollination. The interest in zygomorphic 
flowers is increased by the brilliant and bizarre differentiations 
introduced by the color patterns of many species. The whole 
problem of zygomorphy is locked up with the outstanding fact 
that such flowers are almost without exception entomophilous 
(Fig. 21, A and B). Some of the better known and more striking 
features of this relationship to insects are treated in the chapter 
on the work of flowers. 

The Stamens. The next regular flower parts seen as we go 
into a flower from the outside are the stamens (Fig. 12). These 
are attached to the torus in one or more series inside the corolla 
(Fig. 8), or, in the gamopetalous corolla, they are usually attached 
to the inner surface (Figs. 10 and 11) of the corolla tube. The 
group of stamens is sometimes called the "andrcecium." The 



STRUCTURE OF THE FLOWER 



17 




number of stamens per flower varies greatly in different species. 
The flowers of cattail (Fig. 185), willow (Figs. 3 and 127) and 
ash often have but a single stamen. The flower of the olive 
(Fig. 134) has two, and most grass flowers (Figs. 193, 194 and 
196) have three stamens. Many flowers have four or five and 
some have many stamens. A single flower of the saguaro or 
great cactus, Carnegiea, had 3,482 stamens by actual count. 

Structure of Stamens. Each stamen usually consists of a. 
more or less elongated and narrow, slender stalk or filament, 
bearing an oblong, inflated, two-lobed, bag-like anther at the 
top (Fig. 12). The filament 
is very short or even entirely 
lacking in some flowers so 
that the anther is brought 
down very close to the torus 
or corolla tube, as the case 
may be, but in others the 
filament is greatly elongated, 
very thin, slender and thread- 
like in comparison with the 
rather bulky anther. The 
attachment of the anther to 
the filament is either at the 
lower end of the anther, i.e., 
basal, or laterally near the 

central axis of the anther, i.e., versatile (Fig. 12). The stamens of 
a given flower are usually free or separate from each other, but in 
a few groups they become united either by their filaments or by 
their anthers (Fig. 12, H). Thus in the androecium of the 
mallows the filaments of the many stamens are united well up 
toward the anthers so that a complete sheath is formed that 
envelops the ovary (Fig. 12, H). The many stamens of the 
orange flower are united into several groups by the union of the 
filaments. In the pea (Fig. 146, D) there are two sets of stamens, 
nine in one set in which the filaments are united, and one sepa- 
rate stamen. In the thistles and their kin (Fig. 177, D) the 
filaments are free but the anthers are joined together forming a 
tube through which the style pushes. 

The Anther. The anther when young contains from one to 
four elongated cavities (called "cells") in which the pollen grains 
(Fig. 13) arise. When the anther is mature it usually contains 



FIG. 12. Various types of stamens 
showing various forms of dehiscence. 
A, Ccdandrinia; B, bearberry, Arcto- 
staphylos; C, balm, Melitssa, D, globe- 
daisy, Globularia; E, barberry, Herberts; 



18 



FLOWERS AND FLOWERING PLANTS 



two pollen cavities or cells in each of which quantities of pow- 
dery or waxy pollen are produced. The two cells are often 
separated by the upper portion of the filament, the con- 
nective, which is prolonged from base to tip of the anther. The 
anther cells usually open when the pollen is mature by the 
formation of an apical pore in each sac, or more commonly by a 
longitudinal slit (Fig. 12, A, B and F), through which the pollen 
grains sift out. 

Pollen and Pollen Grains. The pollen grains are usually so 
small as to appear as very tiny specks to the unaided eye, but 
they may be produced in such numbers as to form clouds of 

pollen at the time of 
maximum discharge and 
they sometimes cover 
the ground underneath 
plants with a layer of 





FIG. 13. FIG. 14 

Fia. 13. Pollen grains from various species. A, monkey flower, Mimulus, 

B, a mallow, Hibiscus; C, mallow, Malva; />, gentian, Qeritiana; E, climbing 

bells, Cobaca; F, nightshade, Circaca; G, pink, Dianthus; //, pumpkin, Cucurbita; 

/, bindweed, Convolvulus; J, dandelion, Taraxacum (after Kerncr). 

FIG. 14.- A single pollen grain germinating. Tho exino and intine show 

plainly (redrawn). 

impalpable greenish or yellowish powder. The enormous number 
of pollen grains produced by higher plants is one of their most 
astounding characteristics. This has been judged as a very 
wasteful habit because of the fact that much more pollen is 
produced than appears to be needed. 

Structure of Pollen Grains. The individual pollen grains are 
usually unicellular and their form (Fig. 13) varies considerably 
for different flowering plants but they are usually more or less 
spherical, ovoid, or disk-like. The cell wall is in two layers, 
the one a delicate inner layer, known as the "intine," and the 
other a heavier and more resistant outer layer, the "exine" 
(Fig. 14). The thick exine is often thrown into striking folds, 
bands, ridges, or low protuberances and spines. Germ pores 
(Fig. 14) are located in the exine among the other markings 



STRUCTURE OF THE FLOWER 19 

that appear on the surface. The pollen tube (Fig. 14) emerges 
from one of these pores when the pollen grain germinates. The 
germ pores of the pollen grains in some squashes are covered by a 
lid which pops off when the pollen tube is ready to emerge during 
the early period of germination. The 'number and location of 
the germ pores are usually constant for a given species. These 
features give a surface configuration to pollen grains which is so 
nearly characteristic of the different species that it may be used 
for purposes of identification. 

The Pistil. The fourth and innermost part of the complete 
flower is the pistil (Figs. 1, 3, 4 and 15) or group of pistils which 
lie in the center of the flowor upon the top of the torus (superior) 
or are embedded within it (inferior) and are surrounded by the 
stamens, petals, and sepals. The three common relationships 




FIG. 15. Certain forms of pistils and ovaries. A, rose mallow, Hibiscus 
(after Baillon); B, tea, Thea (after Baillori); C, grass of Parnassus, Parnassia 
(after Mathewx); D, sundew, Drotera; E, diagram of the transverse section of a 
tricarpellary ovary 

between the pistil and the receptacle or torus have already, been 
discussed. We will confine our study in this place to the finer 
structure and variations of the pistil itself. The number of 
pistils in each flower differs greatly for different species. The 
flowers of some plants produce a single, simple pistil as in the 
cherry and peach, while others produce two, three, four, five or 
more separate or united carpels per flower (Fig. 15). The pistil 
or group of pistils in a flower is known as the "gynceceum." 

Nature of the Pistil: The pistil is normally flask-shaped or 
bottle-shaped and is made up of three parts or subdivisions. 
The enlarged, more or less bulbous, hollow, basal portion is 
termed the "ovary." The ovary is commonly drawn out into 
an elongated neck, the "style." The tip or expanded or divided 



20 FLOWERS AND FLOWERING PLANTS 

extremity of the style is commonly roughened and glandular 
and is termed the " stigma" (Figs. 1 and 15). The style is very 
short and even lacking in some flowers so that the stigma is 
sessile, i.e. brought down very close to or directly upon the ovary. 

The Ovary and Ovules. The ovary is the part of the pistil 
which bears the ovules. This is a hollow structure in which 
the ovules are borne in definite positions along the inner wall of 
the ovary (Fig. 15, D) or upon the central axis or floor (Fig. 1, C) of 
that important structure. Some flowers produce but a single 
ovule in the pistil, but most flowers produce several (Fig. 15, 
C and D) and a few species produce several hundred or even 
thousands. A single flower of the giant cactus, Carnegiea, 
showed (by actual count) 1,980 ovules. 

Simple Pistils and Compound Pistils. So far we have had in 
mind a single or simple pistil. This simple pistil or carpel in 
the very young flower is a flattish structure which gradually 
becomes hollowed out and folded so that the margins unite to 
form a closed, pouch-like organ bearing the ovule or ovules along 
the suture (placenta) formed by the union of the two margins 
(Fig. 15, D). In some species there are several or even many 
simple pistils of this sort in each flower, and they remain distinct, 
i.e., not united, and later they ripen into individual, separate 
fruits. But in most flowering plants having flowers with several 
or many carpels per flower the carpels become united to form a 
compound pistil (Fig. 15). The sutures of the individual carpels 
in a compound ovary are axially placed and the midribs are exter- 
nal so that a compound ovary often contains as many cavities or 
" cells " as' there are carpels represented. A compound ovary 
becomes " one-celled" in some flowers (primrose, violet) by the 
disappearance of the septa between the different carpels. 

Degree of Union of Carpels. The union of the carpels in a 
compound ovary is sometimes so complete as to affect the style 
and even the stigma (Fig. 15) where little hint as to the actual 
condition may be seen. In flowers where there are two or more 
separate styles or stigmas it is often safe to assume that the ovary 
is compound. The number of subdivisions in the style or stigma 
(Fig. 15) in such cases may indicate the number of carpels in the 
ovary, but this relation is not always conclusive. The number 
of carpels in a compound ovary is often indicated also by con- 
spicuous longitudinal ridges or creases on the outer surface of 
the ovary, but this relationship may also be misleading. The 



STRUCTURE OF THE FLOWER 21 

number of carpels represented in an ovary can usually be deter- 
mined in most plants only by making thin sections (Fig. 15) 
across the median part of the structure and noting the number of 
locules or cells. In such sections of one-celled, compound 
ovaries the number of parietal placentae may be indicative of the 
number of carpels present. 

Importance of the Ovules. The most important part of the 
pistil is the ovule because that is the structure in which the egg is 
formed and in which fertilization occurs. After fertilization the 
embryo plant develops within the ovule to a certain degree when the 
whole structure becomes transformed into a seed, and as such it 
usually separates from the body of the parent plant. The ovules 
are in reality the forerunners of seeds. 

Number and Nature of Ovules. The number of ovules per 
pistil or carpel varies greatly for different species, but as a rule 
there are two or more ovules per simple pistil or per carpel in 
polycarpellate pistils. In some of the species of the buckwheat 
family, and typically in the grasses, there is a single ovule in 
each ovary. There are many flowers with one or more carpels 
represented in the ovary in which but a single seed matures, all 
of the other ovules having aborted and disappeared. Even in 
such regularly single-seeded fruits as cherries, plums, and almonds, 
a fruit with two seeds is occasionally found. The game of our 
childhood as we looked expectantly to find a "filopena" when 
we were cracking almonds or peach pits recalls this fact. The 
simple pistil of these plants always has two ovules, but usually 
one of them is aborted. Certain other species, such as primroses, 
tobacco, snapdragons, cactuses, and orchids with compound 
ovaries, produce scores or even hundreds of ovules per ovary, but 
all of these may not develop into seeds in every case. The ovules 
in a single flower of the giant cactus, Carnegiea, were counted and 
it was found that there were 1,980 of them, but as a rule the 
juicy fruits of that species produce but a few mature seeds. 

Position of Ovules in the Ovary. Each ovule is an oval or egg- 
shaped body attached by a stalk, the funiculus, to its axis or 
placenta inside the ovary (Fig. 24). The part of the ovary 
to which the ovules are attached is called the "placenta." The 
placentae are commonly located along the sutures formed by the 
union of the edges of the carpel as it closes in its very early 
growth. The number of placentae in an ovary usually is the 
same as the number of carpels represented in the ovary. The 



22 



FLOWERS AND FLOWERING PLANTS 



placentae are said to be " parietal" (Fig. 15, C and D) if they are 
on the outer ovary wall as in the willow and currant; if they are 
borne by the central axis of the ovary (the common axis of the 
carpels) they are said to be "axillary," (Figs. 106, 107, 186 and 
201) as in lilies, irises, etc. In the primroses (Fig. 128) the parti- 
tions between the five carpels of the ovary disappear very early, 
thus leaving a mass of tissue in the basal portion of the ovary, 
the remnant of the axis, upon which the ovules are attached. 
This type of ovule insertion is called "free central placentation." 

INCOMPLETE FLOWERS 

Flowers Lacking Perianth. The regulation features of com- 
plete flowers have been considered here, but it will be recalled 
that it was pointed out in the introduction that not all flowers 




Fio. 16. Incomplete flowers. A, male flower of amaranth, Amaranthus; 
B, female flower of Amaranthas (both after Le M. and Dec.); C, female flowers of 
hazel, Corylus (after Baillon); D and E, female and male flowers respectively 
of pistachio, Pi^tacia (after Le M. and Dec.); F, male flower of walnut, Juglans, 
(after Le M. and Dec.); G and H, apetalous flowers of elm, Ulmus (after Le M. 
and Dec.); I and J", male and female flowers respectively of nettle, Urtica (after 
Le M. and Dec.). 

are complete. The flowers of many species of flowering plants 
lack one or more of the regular parts (Fig. 16). The petals are 
lacking in some cases, as in certain buttercups, buckwheats, and 
nettles, and in still others the sepals are also lacking so that 
there is no perianth present at all as in willows, duckweeds, 
pepper, Trachodendron. The flowers of many other species 
produce a very inconspicuous calyx or only the merest vestiges 
of a perianth, as in figs, valerian, and composites. Many 
flowers are known in which the perianth is lacking wholly or 
in part, but these flowers contain stamens and pistils (Fig. 16). 
Such flowers are incomplete, in that they lack the perianth, the 
accessory parts of a flower, but they are, nevertheless, perfect, 



STRUCTURE OF THE FLOWER 23 

because they possess stamens and pistils, the essential organs of 
a flower. These are monoclinous, or perfect flowers. 

Diclinous Flowers. There arc other flowering plants in which 
the whole perianth is present or absent, or the calyx alone may 
be present, and in which there are only stamens or pistils but not 
both (Figs. 2, 3, 4 and 16). This is the situation in willow, cotton- 
wood, hickory, oak, walnut, spurge, green ash, boxelder, maize, 
wild rice, cattail, arrowhead, grape, chestnut, bittersweet, and 
some members of the buckwheat family. This phenomenon is 
included under the term "dicliny," or the condition known as 
"diclinism." Two common conditions prevail among such spe- 
cies. In one group the pistillate (female) and staminate (male) 
flowers are borne by the same individual but upon different parts, 
i.e., not in the same flower. Such plants are said to be "monoe- 
cious." The hickory, oak, chestnut, walnut, cattail, maize, 
arrowhead, cucumber, and spurge represent this condition (Figs. 
167, 168 and 182). In the other group, the stamens and pistils 
are not only borne by different flowers but these flowers are also 
produced by totally different individual plants. Such species are 
said to be "dioscious." The willow, cottonwood, green ash, 
papaya, boxelder, hemp, datepalm, hop, mulberry, osage orange, 
tree-of-Heaven, etc., represent this type (Figs. 3, 16, 127). 

Comparisons with Animals. It will be seen at once that 
dioecious flowering plants are sexually differentiated much as 
are the higher animals, that is, the individuals of this nature 
are male or female but not both male and female, as is true of 
the individuals that are monoecious and that produce perfect 
flowers. Obviously, if one wishes to produce fruits and seeds in 
diclinous species he must have both pistillate and staminate 
individuals in close enough proximity to insure pollination. It 
is interesting to note,, in passing, that sexual differentiation has 
not gone so far, that is, it has not affected nearly so large a pro- 
portion of flowering plants, the highest plants known, as it has 
in the mammals, the highest animals. 

Polygamous Species. A few species of flowering plants that 
produce their stamens and pistils in different flowers also pro- 
duce perfect flowers. Such plants are said to be " polygamous." 
Certain species of maple, ash, and buckwheat are of this nature. 
These combine various degrees of monocliny and dicliny. 

Flower-like Structures. Reference should be made to certain 
interesting flower-like structures commonly regarded as flowers 



24 



FLOWERS AND FLOWERING PLANTS 



(Figs. 17 and 18) that in reality are not flowers, or perhaps more 
than flowers. The Poinsettia, a popular Christmas house plant 
in America, will serve to illustrate one of these peculiar features. 
The large, beautiful, and showy group of bright scarlet structures 
at the top of the branches, sometimes 6 or 8 inches in diameter 
is usually considered a flower, popularly. However, the true 
morphology of that structure is quite different from what is 
commonly supposed. The large, scarlet, leaf-like parts are in 
reality leaves that develop a red pigment in place of the usual 
chlorophyll. Taken together these con- 
stitute a radial fringe known as an 
"involucre," which really performs the 
function of the regular perianth, but 
which is a distinct affair and wholly 
separate from the inconspicuous true 





FIG. 17. Fia. 18. 

FIG. 17. The showy involucre of dogwood, Cornus florida, with the group 
of small flowers in the center. The whole structure passes as a single flower, 
popularly, (after Baillon). 

FIG. IS. Unopened and mature heads of marigold, Calendula officinalis, 
showing the closed involucre iri the young heads and the ray and disk flowers 
in the opened head (after Baillon). 

flowers that are clustered near the center of the whorl of brightly 
colored bracts. Similar features are associated with the flowers 
or flower clusters in certain dogwoods, Comics florida (Fig. 17), 
clematis, and Japanese paper plant. 

The Flowers of Composites. The Compositae, to which belong 
sunflowers, asters, daisies, dandelions, goldenrods, calendulas, 
thistles, chrysanthemums, and their kin, are unique in that the 
structure that is commonly called a " flower" is in truth a cluster 
of many flowers (Fig. 18). A single " flower" in a dandelion 



STRUCTURE Ob' THE FLOWER 



25 



(Fig. 178) often contains as many as 100 to 200 tiny, separate, 
very closely grouped flowers on a common receptacle. This 
flower cluster is known to botanists as a "head." The heads in 
the big Russian sunflower usually contain several hundred 
individual flowers which become transformed into a correspond- 
ing number of dry fruits (achenes) or "seeds" arranged in a 
beautifully symmetrical pattern over the greatly enlarged 
receptacle. The composites, the dogwood and Poinsettia and 
their kin furnish fine material for the discussion of the question 
of "when is a flower not a flower" or "when is a flower more 
than a flower." 

Pathological Growths. Travelers in the tropics sometimes note 
curious saucer-like, woody growths on the roots of certain trees 
that grow in that part of the world. These are sometimes several 
inches broad and they exhibit a beautiful radiate symmetry, 
with fringed or lacerated border, but evidently formed from wood. 
These "wooden flowers" are not flowers at all, of course, but 
abnormal or pathological growths produced as the result of the 
action of some mistletoe parasite that infects the trees. 



Complete 
flowers 



SUMMARY OF THE ORGANIZATION OF FLOWERS 

Pedicel or peduncle 
Floral bract 
Axis or receptacle 
Glandular disk 

Calyx, sepals \ ,. ., 
I. Perianth 



Accessory 
parts 



( Corolla, petals 



| St! 



/ Fih 
Stamen \ Am 



lament 
ther, pollen, sperms 



Essential 
parts 



Pistil 



Stigma 

Style 

Ovary, ovules, 



Perfect or 

monoolmous 

flowers 



Incomplete 
flowers 



[ Accessory parts 
lacking, flowers 
incomplete 



Essential parts lack- 
ing, flowers incom- 
plete and imperfect, 
diclinous 



f Petals absent, apetalous flowers 



Petals and sepals absent apetafeous 
i and asepalous flowers 

Stamens and pistils in separate! Monoecious 
flowers on the same individual [species 

Stamens and pistils in separate } Dioecious 
flowers on different individuals / species 



CHAPTER III 
THE WORK OF THE FLOWER 

The preceding chapters have largely dealt with the flower from 
the anatomical and morphological standpoints, although refer- 
ence to processes and functions were not altogether lacking. A 
study of the flower as a living, working unit will now be presented. 
Flowers are understood in their true value and significance only if 
the dynamic role that they perform in the life history of flowering 
plants is appreciated. 

Significance of Reproduction. A very large proportion of the 
energy of plants is devoted toward the preparation of new 
individuals for succeeding generations. Reproduction, in a word, 
is the most significant of all of the vitally active processes common 
to flowering plants because herein lie most of the potentialities 
for the future. 

The flower has already been characterized as the unit of sexual 
reproduction, par excellence, in flowering plants. The associa- 
tion of flowers with seed production is common knowledge, 
but comparatively few students are familiar with the sequence of 
details associated with the phenomenon. Flower structure will 
be examined in somewhat greater detail than has already been 
done in order that the outline of this important and dynamic 
process in the life of flowering plants may be sketched. 

The General Nature of 8ex. Sexual reproduction normally 
occurs only when two sex cells, one a sperm, the male cell, and the 
other an egg, the female cell, or their equivalent, each carrying 
certain inheritances of the parent organism, come into intimate 
contact so that their contents become inseparably united with each 
other to produce a zygote, which is at once the first cell of the new 
individual. The sperm alone never develops a new individual, 
and it is very rarely that the egg is capable of further development 
until it is fertilized by a sperm. The development of an embryo 
from an unfertilized egg is known in a very few species of flowering 
plants, and in some such the phenomenon by no means takes the 
place of the regular behavior. The process is known as "par- 

26 



THE WORK OF THE FLOWER 27 

thenogenesis," and it has been reported in the dandelion, meadow 
rue, everlasting (Antennaria), Akhemilla, and possibly others. 

Sexuality in Flowers. Fertilization in flowers is involved in a 
series of more or less complex structures and activities, but these 
may be reduced to about five, all of which are preliminary and 
subsidiary to the last which is the most important and crowning 
event. The plant must provide male cells, sperms, and female 
cells, eggs. This it does, as has already been noted, in the pollen 
grains of stamens (Figs. 12, 13, 14 and 25), and in the ovules of 
the ovaries (Figs. 1, 4, 15, 23 and 26). Then the pollen grains 
must be carried from the anthers to the stigma of the pistil 
(pollination). Then the pollen tube must be developed in order 
that the sperms may be carried through the tissues of stigma and 
style to the ovules in the ovary within which the eggs are located. 
When the pollen tube enters the ovule and discharges the sperms 
in the immediate vicinity of the egg, fertilization (Fig. 25), or the 
fusion of the sex cells, is readily accomplished. 

POLLINATION 

Pollination, by which is meant the transfer of pollen grains 
from anther to stigma in flowers, as a forerunner of fertilization, 
is one of the most varied, important, and interesting phases of 
the work of flowers. And yet the plant in itself may have little 
to do with this process directly, because pollination is often 
brought about by some external agency such as wind or water, 
or even by a totally separate and different organism such as a 
bee, moth, or bird. 

Self-pollination versus Cross-pollination. One might natu- 
rally suppose that the pollen produced by a given flower would 
pollinate that flower and that the sperms produced by certain 
of those pollen grains would fertilize the eggs in the ovules 
of the same flower. This would be self-pollination and self- 
fertilization. This actually happens in certain species, but it is 
not by any means the rule among flowering plants. The vast 
majority of flowering plants appear to have worked out the 
details of their development so that self-fertilization is prevented. 
The fact is that cross-pollination and, therefore, usually also 
cross-fertilization is the rule among flowering plants. Indeed, 
cross-fertilization is also the rule in the groups below the Angio- 
sperms. It would appear that some great biological significance 
is associated with this fact. Many experiments since the time of 



28 FLOWERS AND FLOWERING PLANTS 

Darwin support the contention of that great investigator that 
cross-pollination (cross-fertilization) generally results in the 
development of stronger individual plants and a stronger race. 

Effect of Inbreeding. Plants or animals that are produced by 
self-fertilization are said to be "inbred." The effects of inbreed- 
ing are strikingly illustrated in the first generation of corn (maize) 
produced by this method. The individual plants are very 
noticeably dwarfed as a whole and the ears that they form are 
greatly reduced in size and often distorted or otherwise abnormal 
and poorly filled. When individuals of this sort are cross-bred 
again the vigor may be at once restored in much the original 
form and degree. 

Types of Pollination. Students of pollination phenomena 
refer to self-pollination as " autogamy/' and to cross-pollination 
as "allogamy." Cross-pollination (allogamy) between flowers 
of a given individual is termed "geito- 
nogamy," and between flowers of totally 
separate individual plants "xenogamy." 
Geitonogamy occurs in those plants that 
have monoclinous flowers, i.e., those with 
perfect flowers, and also in those that are 
monoecious, i.e., those species with stam- 
FIG. 19.- Dimorphism inate and pistillate flowers separated 
in partridge berry, Mitch- upon different parts of the individual. 

ella. A. flower with long . . 

style and short stamens; B, Xenogamy alone is possible in plants 
flower with short style and w jth imperfect flowers and in dioecious 
long stamens. . . ., . ., . . , , 

species, i.e., those with stammate and 

pistillate flowers borne by totally different individuals of the 
species. 

How Flowers Prevent Self -pollination. The advantages asso- 
ciated with cross-pollination and cross-fertilization are reflected 
in the great variety of flower behavior and in the bizarre floral 
structures that have been developed through the ages that tend 
to prevent self-fertilization. .The flowers of diclinous species 
must of course be cross-pollinated. The stamens and stigmas 
in monoclinic species usually mature at different times. This 
naturally prevents self-fertilization, and at the same time 
renders cross-fertilization imperative. Flowers of this sort are 
said to be "dichogamous," and the phenomenon is termed 
" dichogamy. " Such flowers are said to be " protandrous " if 
the pollen is mature before the stigma is receptive, and "protogy- 




THE WORK OF THE FLOWER 29 

nous" if the stigma is ready before the pollen is mature. Certain 
monoclinous flowers (primrose, partridge berry, etc., Fig. 19) 
prevent self-pollination to a considerable degree by an interesting 
type of dimorphism. Some of the flowers of this plant bear 
their stamens high upon the corolla tube, near the open throat 
of the corolla, but the stigma is much lower down in the tube and 
never approaches the anther. In other flowers the stamens 
are inserted low down on the inner surface of the corolla tube, 
and the stigma occupies the position about level with the throat 
of the corolla (Fig. 19). Now the eggs in the ovules of the flower 
with low stigma may be fertilized only by sperms produced in the 
pollen grains of the stamens that are placed low, and the eggs in 
the flower with the stigma in the throat may be fertilized by the 
sperms of pollen grains borne by the stamens in the throat. 
This floral pattern renders cross-pollination imperative. There 
are still other flowering plants that produce flowers that are 
sterile to their own pollen, and, because of this, pollen from 
another source is necessitated. The iris prevents self-pollination 
by placing its stamens in a close-fitting groove underneath the 
petal-like lobes (Fig. 201) of the style in which the stigmatic 
surfaces are on the upper surface. The anthers are held very 
closely pressed against the under surface by the tensed filaments. 
The pollinating bee strikes the stigma only as he enters the 
flower so that foreign pollen alone is deposited. After working 
the flower the bee leaves without touching the stigma so that 
the pollen of a given flower is rarely deposited upon its own 
stigma. 

External Factors in Cross-pollination. The most effective 
agents that bring about cross-pollination are water, wind, and 
animals including insects, and a few other types. Not many 
flowering plants are pollinated by water. Some of these, 
Ceratophyllum, Zostera,' are totally submerged and are pollinated 
under the water. In other cases, Ruppia, Callitriche, the pollen 
floats on the surface of the water where it comes into contact 
with the stigma. One of the most interesting and best known 
cases of pollination by means of water is in the eelgrass, Vallis- 
neria spiralis, a submerged plant with grass-like leaves, which is 
more or less common in lakes and ponds. This is a dioecious 
species in which the pistillate flowers are borne upon a slender 
thread-like scape that stretches upward until the flowers are 
brought to the surface of the water. The staminate flowers 



30 



FLOWERS AND FLOWERING PLANTS 



are borne beneath the water but when about mature they break 
off and rise to the surface where they expand as floating flowers 
and discharge their pollen. After the stigmas of the pistillate 
flowers receive the pollen from the floating staininate flowers 
the scapes contract spirally and the fruits are ripened beneath 
the surface. A somewhat similar case has been described for the 
waterweed, Elodea canadensis. Other aquatic species in which 
the plant is wholly submerged raise their flowers well above the 
surface of the water and the pollen may then be carried by wind 
or insects, as in the lacoleaf, Aponogeton fenestralis, and the 
water buttercup, Batrachium trichophyllum. The flowers of some 
submerged aquatic species, as in the latter, may not open 
because of abnormally high water and so self-pollination becomes 
the rule under such conditions. 

Cross-pollination ~by Wind. Many flowering plants and prac- 
tically all Gymnosperms are usually pollinated by wind. The 




FIG. 20. Wind-pollinated flowers. A, male catkins of birch, Betula; B, 
female flowers of hazel, Cory I us, C, male catkin of willow, Sahx; D, female 
flower of Sahx, E, perfect flower of wheat, Triticitm (after BaiHon). 

influence of other pollinating agents is negligible among the latter. 
Perhaps the most conspicuous wind-pollinated, or anemophilous, 
flowering plants are the members of the group " amentif erae " 
including the willows, Salix, poplars, Populus, oaks, Quercus, 
hickories, Hicoria, chestnuts, Castanea, beeches, Fagus, birches, 
Betula, hazels, Corylus, alders, Alnus, hornbeam, Ostrya, etc. 
(Figs. 20, 167, 168 and 169), and the grasses, including the 
cereals (Gramineae) (Figs. 193 to 199), sedges (Cyperaceae) (Fig. 
192), and certain species of other groups such as the elms, Ulmus, 
nettles, Urtica, Urticastrum, hops, Humulus, etc. (Figs. 108 and 
110). 



THE WORK OF THE FLOWER 31 

Nature of Wind-pollinated Flowers. Wind-pollinated flowering 
plants are commonly characterized by flowers that are incon- 
spicuous because of their size or lack of nectar or odor and 
brilliant colors, and by the production of a great abundance of 
dry or oily powdery pollen. The stigmas of such flowers are 
often much branched or plume-like, feathery, or hairy. These 
details doubtless assist in the Catchment of greater numbers of 
pollen grains than would otherwise be possible. The minute 
size and lightness of pollen grains contribute to the ease with 
which they are carried by the wind, but doubtless a very small 
number, compared with the enormous numbers liberated, ever 
reach the stigmas. Uncountable numbers of wind-carried pollen 
grains never reach the flowers and so are lost without performing 
their function. It would seem that many anemophilous species 
could greatly reduce the amount of pollen produced and still 
take little chance of becoming weakened or threatened by 
extinction. 

Amount of Pollen Produced. The quantity of pollen produced 
in anemophilous flowering plants has been investigated for a 
number of species. Thus Hassall, about a hundred years ago, 
found nearly 250,000 pollen grains in a single blossom of dandelion, 
Taraxacum (Fig. 179). A peony, Paeonia, flower with 175 
stamens produced 21,000 pollen grains per stamen or a total 
of 3,675,000 for the flower. A rhododendron plant produced 
72,600,000 pollen grains. The amount of pollen in Indian 
corn is usually impressive as one walks through a field at the 
time of blooming. The ground is often covered by a dusty 
layer of pollen at such time and the plants themselves are envel- 
oped in a powdery mantle of pollen. One investigator reports 
that a single plant of maize produced as many as 50,000,000 
pollen grains. 

Pollination in the Grasses. Not all grasses are pollen-pro- 
ducers like -maize. The low-growing species, especially, produce 
less; but perhaps the low stature and the density of the popu- 
lation in such species more than compensate for the relatively 
small pollen crop. Another advantage in such species is seen 
in the fact that the pollen sifts through and is blown thoroughly 
about among the individuals of the denser grassy associations 
before it is carried away. It should also be noted that the flowers 
of many "wind-pollinated species are reduced or incomplete in 
that they lack petals or even both petals and sepals, so that the 



32 FLOWERS AND FLOWERING PLANTS 

material and energy that go into the formation of the perianth 
may be available for stamen and pollen formation. 

Distances Involved in Pollination. The distance to which 
pollen grains are ordinarily carried by the wind is probably 
not as great as might be supposed. The data on this question 
are rather few and somewhat uncertain. Finely divided dust 
has been carried by the wind fl^m Africa to Switzerland, and 
the pollen grains of pine have been blown 400 miles or more from 
where they were produced. Pollen has been gathered on ships 
at sea 20 to 40 miles from shore. The tiny seeds of a certain 
pitcher plant, Nepenthes ampullaria, are reported to have been 
carried by the wind for 1,500 miles. So that it is possible that 
the pollen grains of many anemophilous species are occasionally 
carried for great distances by the wind, but the biological impor- 
tance of thjs fact is doubtless more interesting than significant. 
The relatively short period of viability and the vicissitudes 
imposed by meteorological conditions tend to support this 
conclusion. 

Animals as Pollinating Agents. There are many more species 
of flowering plants pollinated by animals than by all other agencies 
combined. The insects are by far the most important animals 
concerned here, but a few flowering plants, Abuhlon, Fuchsia 
(Fig. 156), FritillaricLy Bignonia, Lonioera, Oenothera (Fig. 156), 
and Impatiens, are pollinated by birds, especially humming 
birds. Certain tropical species are pollinated by bats, and a few, 
Arisaema, Calla, Aspidistra, by snails and slugs. The interrela- 
tions between flowers and insects have attracted biologists for 
many decades. There are numerous publications on this sub- 
ject in many languages from all parts of the world. 

Pollination by Insects. Insect-pollinated flowers produce less 
pollen than do anemophilous species, but this reduction is amply 
compensated for in the numerous, extremely varied, and often 
bizarre floral modifications that render insect-pollination certain 
(Fig. 21). The perianth is of the utmost value in such flowers. 
It seems probable that the color, odor, size, and form of flowers 
are largely to be interpreted in terms of the attractiveness 
afforded for the insect visitors. The intimacy of the dependence 
of certain flowers upon certain insects for pollination is often 
impressive. Thus F. Darwin writes that: 

"The coordination between a flower and the particular insect 
which fertilizes it may be as delicate as that between a clock and 



THE WOtiK OF THE FLOWER 33 

its key." The son of the great Darwin meant pollination by 
" fertilization " in the statement quoted, of course, because insects 
do not fertilize flowers at all. We should expand the figure and 
understand that insects may apply the key (pollen) to the socket 
(stigma) but unless the spring (egg) is wound (fertilized) the clock 
(new generation) is impotent. ^ 




Fio 21 -Insect-pollinated flowers A, mechanism m sago, Sal via glutinosa; 

B, the stamens of Salvia showing the long curved filaments and the connective; 

C, orchid, Orchis; D, lady's slipper, Cypripcdium (after Le M. and Dec.); E, 
Orchis (after Le M. and Dec.); F, balsam, Impatient* (after Le M. and Dec.}; G, 
larkspur, Delphinium (after Le M. and Dec.); //, nasturtium, Tropaeolurn (after 
Le M. and Dec.); /, a tropical orchid, PhaJaenopsis (after Kerner); J, snapdragon, 
Antirrhinum (after Le M. and Dec.). 

Danger of Exaggeration. This is a field of biology with so much 
that is impressive that one may become so enthusiastic as to 
slip very easily (almost unconsciously) in the pitfall of teleological 
reasoning. Many rather uncertain statements have been made 
concerning the constancy of insect attention and the close degree 
of correlation between shape of flower and insect, weight of 
insects and. floral mechanisms, color and odor and insect species, 
etc. Recent extensive experimentation would indicate that the 
commonly supposed delicacy and intimacy of such correlations 
may be considerably exaggerated. Further investigations may 
remove some of the "romance" from this alluring field, but they 
will probably endow it with even a greater wealth of definitely 
established scientific truth than is at present available. 

Why and How Flowers Attract Insects. Insects visit flowers 
because they have found that flowers have something important 



34 FLOWERS AND FLOWERING PLANTS 

to contribute to their material welfare. They do not enjoy 
flowers simply for their color or odor, but for the food that they 
secure, prosaic as this may seem. The visitors are attracted by 
brilliantly colored and openly displayed banners and more or 
less sweet-smelling perfumes, but they go to flowers to get a 
sustaining volume of food in the form of pollen and nectar. 
The poetized busy bee improves each " shining hour'* in calling 
upon its floral neighbors, primarily, in order that it and its 
associates will have something to eat when darkness surrounds its 
visits with uncertainty and when winter comes to lay waste 
to its store of fresh food. The colors and odors that attract 
the insects are mostly pleasant or agreeable to us also, and we 
utilize the colors for decorative purposes and extract many of the 
pleasant odors for the preparation of perfumes, but, of course, 
these are not features of concern on the part of the flowers or 
insects. The olfactory preference of some animal pollinators 
must vary considerably from ours because we find them visiting 
certain flowers, as in carrion-flower, Smilax herbacea, skunk 
cabbage, Spathyema, and fetid milkweed, Stapelia, etc., in which 
the odor is exceedingly unpleasant and nauseating. 

Quantity of Pollen Gathered. Many insects consume quanti- 
ties of pollen as food which they get from inconspicuous and 
scentless flowers as well as from flowers of the more popular 
nature. Brilliant flowers are sometimes scentless (at least to 
man) but they are visited by insects for the pollen that they 
produce. The amount of pollen consumed by insects is probably 
inconsequential since there is still an abundance for fertilization, 
but the masses of pollen that certain insects (bumblebees) eat 
and collect is rather impressive. Clements and Long report 
that the honeybee, Apis mellifica, sometimes carries a load of 
pollen (of Rubus deliciosus) that is more than half the weight of 
the bee, but the load was usually less than that. In another bee, 
Andrena crataegi, the pollen load varied from 5 to 17 per cent, 
and in a bumblebee, Bombus juxtus, from 1 to 61 per cent of the 
insect's weight in twenty-three determinations. Sometimes the 
load of pollen was pure, i.e. } from a single plant, but in other 
cases the load represented a mixture of the pollens from two or 
more plants. Flowers have developed many different structural 
devices to assist in sprinkling or dusting the insect with pollen 
and to insure the loading of the insect in a manner which will 
best suit cross-pollination demands. 



THE WORK OF THE FLOWER 



35 



The Nectar of Flowers. The flowers of many species are 
attractive to insects or other pollinating animals because of the 
presence of nectar which is also a valuable food. Nectar is 
gathered from flowers and stored for future use in enormous 
quantities as honey. The nectar is a saccharine exudation 
produced by areas of glandular tissue in various parts of flowers. 
The nectar-forming structure is commonly called a "nectary" 
(Fig. 22). Nectaries are usually so placed in a flower that the 
insect cannot reach them without becoming dusted with pollen 
and at the same time dusting pollen which he carries from other 
flowers upon the stigma. The nectaries in many flowers are 
cushion-like or cup-shaped (Fig. 22), and are placed at the bottom 
of the sepals (Castanea) or at the base of the petals as in lilies 




FIG. 22 - -Various types of nectaries. A, buckthorn, Rhamnus; B, violet, 
Viola; C, buttercup, Ranunculus, D, columbine, Aqmlc,()ia (redrawn). 

and buttercups or they may surround the basal part of the pistil. 
Flowers with slender corolla tubes usually have the nectaries 
toward the base of the tube so that the insect must actually 
crawl into the flower, or it must have a long tongue in order to 
get the nectar. In many other species the nectary has become 
a part of some specially formed portion of the flower as in the 
well-known spurs of the petals in the columbine, Aquilegia, and 
in certain distinctive petals in violet, Viola, in many orchids, 
Orchis, Platanthera, Diura, and in Tropaeolum (Fig. 21). A 
certain orchid, Angraecum sesquipedale, of Madagascar, produces 
a nectary that is of the form of a slender whiplash hanging from 
the under surface of the lip of the flower. The nectary reaches a 
length of llj^ inches, and it bears 1 inch or more of nectar in the 
base. This flower is pollinated by a moth with a long tongue or 
proboscis. 

Zygomorphy and Pollination. Plants with zygomorphic or 
irregular flowers (Fig. 21) are of special interest in connection 



36 FLOWERS AND FLOWERING PLANTS 

with a study of cross-pollination by insects. The corolla in 
such species is often of a size and form as to admit only certain 
types of insects on their way to secure pollen or nectar or both. 
Sometimes in these cases as in other tubular corollas an insect 
will cut a hole in the base of the corolla tube opposite the nectary 
and will feed in that manner instead of crawling into the flower. 
The insect cheats the flower in this degree, but fortunately 
there are not many insects that make this manner of feeding 
their regular practice. 

Pollination in the Mints. Members of the mint family, 
Labiatae (Fig. 144), snapdragon family, Scrophulariaceae (Fig. 
141), bean family, Leguminosae (Fig. 146), and the orchid family, 
Orchidaceae (Fig. 203), furnish a great many varieties of zygomor- 
phic flowers and related types of insect behavior. The glutinous 
sage, Salvia glutinosa, will serve to illustrate one of the floral 
mechanisms of mint flowers that assists in securing cross-pollina- 
tion (Fig. 21, A and B). The corolla of the flower in this species 
is very deeply two-lipped, with the upper lip narrow, erect and 
developed in the form of a hood with the two stamens hidden 
underneath. The lower lip (composed of three petals) is broad- 
ened, flattish, and spreading, so as to form a natural landing 
board for the pollinating bee. The nectar is placed in the bottom 
of the slender corolla tube. Each of the two stamens has a 
short, upright filament which is prolonged above into a slender, 
curved connective bearing the anther at the upper end and below 
the point of connection with the filament it is extended into an 
enlarged bulbous or flattened base (Fig. 21, B). The form of 
the entire structure is such that it lies snugly within the narrow 
upper lip of the corolla, with the anther underneath near the 
hood- like top of the lip. The stamen is hinged to the corolla tube 
lightly at the point of the union between filament and connective, 
with the basal or short, rather heavy and blunt segment of the 
connective projecting into the cavity of the corolla tube, and the 
upper portion or much longer and slender segment of the con- 
nective closely following the curved form of the upper lip. The 
stamen is free to swing down and up on the hinge as indicated, 
but the lower, blunt portion of the connective is usually heavier 
than the upper portion of the connective and anther so that 
it serves as a bulb to hold the curved connective and anther 
in the position indicated unless the bulb is depressed by some 
outside force (Fig. 21). When a bee lights upon the expanded 



THE WORK OF THE FLOWER 37 

lower lip and crawls into the corolla tube in search of nectar his 
forehead strikes the bulb or the lower end of the connective 
which is forced downward and backward as he moves farther 
into the corolla. This movement swings the long slender part 
of the connective and the anther from its position underneath 
the hooded upper lip and causes the anther to strike the back 
of the insect's body dusting it with pollen. The slender style 
is also usually placed underneath the upper lip of the corolla, 
but it is usually immature and short at the time the pollen of a 
given flower is ripe. The style matures later and hangs down 
between the two lips of the corolla so that when the bee enters an 
older flower in which the stigma is receptive the slender style is so 
curved that the stigmas strike the back of the bee at the same 
spot at which it was touched by the anthers of the younger flower. 

Pollination in the Orchids. The orchids show many interesting 
and curious adaptations to insure cross-pollination by insects 
(Fig. 21, C, D, E, and /). The case of the Madagascar orchid 
referred to with the long slender nectaries in which pollination 
is accomplished by a moth with a proboscis nearly 12 inches in 
length is one that illustrates to what extremes these relationships 
may go. The flower of the lady's slipper orchid, Cypripedium f 
is also adapted to pollination by insects of a particular kind 
(Fig. 21, D). One of the petals in this flower is formed like an 
inflated bag (the "slipper") with a relatively small aperture in 
the upper surface. The aperture is guarded or partly closed by 
a flap of membranous tissue which permits the entrance of many 
different kinds of insects in search of food. The pollen and 
stigma are so placed as to touch certain insects as they enter 
and leave these bag-like flowers. Certain bees enter the bag-like 
lip of the corolla through the opening in the upper surface. 
Most such insects that enter the sack find difficulty in crawling out 
at the point of entry and so they die and their bodies decompose 
within the sack. Bees with sufficient strength are able to escape 
by pushing their way through the opening between the flap and 
the edge of the aperture. Now, the stigma is on the underside of 
the flap (Fig. 21, D), and near it are two masses of gelatinous 
pollen (pollinia) so placed that the bee gathers them up as he 
crowds his way out of the trap, only to deposit some of them on 
the stigma of another flower when he enters it. 

Sterile Pollen. A curious feature of cross-pollination of flowers 
by insects is seen in the fact that intricately complete modifica- 



38 FLOWERS AND FLOWERING PLANTS 

tions for this purpose have frequently resulted in the development 
of flowers that are absolutely sterile to their own pollen. And, 
on the other hand, dozens of supposedly entomophilous species 
have been found to be habitually self -pollinated. Kirchner 
has reported that this is true in fifteen species of European 
orchids, and about 150 extra-European orchids are known to be 
of the same nature. These facts seem paradoxical in the light of 
the common interpretations of floral behavior that have been 
presented. Why certain plants should go to all the trouble of 
evolving flowers with striking colors and odors that certainly 
attract insects, and with forms so intricately constructed as 
to fit them for the visits of certain insects, and then remain 
self-pollinated and self-fertilized without any evident loss of 
vitality or vigor is indeed a puzzle. The phenomenon should 
at least teach the student that so-called "laws" in the biological 
world are not to be trusted with the constancy of the laws of the 
mathematical and astronomical world. 

Germination of the Pollen Grains. We have learned that the 
principal function of the anther of the stamen is to produce the 
pollen grains. Each pollen grain is one of four 
cells which are developed in a series of pollen 
mother-cells that are deeply embedded in the 
anther. When the pollen sacs open to permit 
the discharge of the pollen grains (or soon there- 
after) each grain normally contains two or three 
cells (nuclei) one of which is called the "tube 
nucleus" and the other one or two are the 
" generative nucleus " or the male cells or sperms. 
FIG. 23. Ger- The pollen grains germinate on the glandular 
^mifihowin^the surface of the stigma and the principal structure 
two sperms and formed is a slender, very delicate, thin-walled 
^edra^)^ 1 ^ tubular structure known as the "pollen tube," in 
the protoplasm of which are embedded the two 
sperms or gamete nuclei and the tube nucleus (Fig. 23). The 
pollen tube emerges from the pollen grain through^pne of the germ 
pores which are characteristic spots in the exine or outer wall of 
the pollen grain. The pollen tube, with the tube nucleus near 
the tip, continues its growth through the style, however long or 
short it may be, until it enters the cavity of the ovary. The 
tube is then directed toward the open end of an ovule which it 
enters. It is reported that the older portion of the pollen tube 




THE WORK OF THE FLOWER 39 

withers as the apex advances farther and farther on its course 
toward the ovary. 

Form and Position of Ovules. The ovules are the most 
significant parts of the pistil for it is within them that the eggs 
are developed. A normal ovule is a tiny, very delicate, oval or 
egg-shaped structure attached to the placenta by means of a 
firm stalk or funiculus (Figs. 24, 25 and 26). In some flowers the 
funiculus is straight and the ovule then stands out straight into 
the cavity of the ovary. This type of ovule is called an "orthot- 
ropous" ovule. The funiculus in other cases is elongated and 
grown to the rest of the ovule which is curved about nearly at 
right angles to the stalk, and thus produces a " campylotropous " 
ovule. In a third type the funiculus of the mature ovule becomes 




FIG. 24. Sectional diagrams of ovaries to show types of ovules and their 
attachment. A, anatropous ovule; B, orthotropous ovule; <7, campylotropous 
ovule. 

curved at the apex to such a degree that the body of the ovule lies 
against it, and completely reversed so that the opening is directed 
toward the placenta. This is the "anatropous" type of ovule. 
The orthotropous ovule is regarded as the most primitive type, 
but the anatropous type is the most common among the modern 
flowering plants (Fig. 24). 

Detailed Structure of the Ovule. Each ovule proper is com- 
posed of one or two coats or integuments enclosing a rounded 
mass of very soft, juicy tissue called the "nucellus" (Fig. 24). 
The integuments grow outward from the funiculus and almost 
completely surround the nucellus, though there is always left 
an opening, called the "micropyle," at the outer end of the ovule. 
Embedded in the nucellar tissue is a relatively large cavity or 
embryo sac, within which there is at first a single large nucleus 
(Figs. 24 and 25). The term is prophetic of the fact that the 
embryo plant of the new generation is to be formed within this 
cavity. The primary embryo-sac nucleus grows and divides a 



40 



FLOWERS AND FLOWERING PLANTS 



number of times to produce eight nuclei which are arranged in 
two groups of four each, one group at the micropylar end and the 
other group at the opposite end of the embryo sac. Then 
one nucleus from each of these groups moves to the center of the 
sac and the two fuse in that position. The group of three nuclei 
at the outer end of the sac is called the "egg apparatus/' One 
of these is the egg, and the other two the synergids (Fig. 25). 

The three nuclei at the oppo- 
site pole are called the "anti- 
podals. " Normally only one 
of the three nuclei in the egg 
apparatus is an egg, but the 
others may possibly serve as 
eggs also under certain un- 
known conditions. The anti- 
podals have also been known 
to produce embryos, as have 
some of the cells of the nuc- 
ellus immediately surrounding 
the embryo sac (Fig. 25). 

FERTILIZATION OF THE EGG 

When the normal cells 
within the emjbryo sac have 

FIG. 25. Diagram to show the general completed the above Cycle of 
anatomy of a complete flower and- the > -, . i , , 

process of fertilization. development, and have be- 

come grouped as indicated, 

the embryo sac is mature and he egg is ready to be fertilized. 
If the sperms from a bursting pollen tube are discharged into 
the embryo sac at this time, one of the sperms unites-with the 
egg and fertilization is thereby accomplished (Figs. $> and 26). 
The other sperm often passes on deeper into the sac/to fuse with 
the equatorial nucleus. This phenomenon has been called 
" double fertilization." 

Development of the Embryo. The fertilized egg or zygote 
absorbs food and begins to grow and divide to form the embryo 
which gradually pushes back into the cavity. Concurrently 
with this development the equatorial nucleus (primary endo- 
sperm nucleus) with which the second sperm fused also begins to 
divide and to form a tissue which comes to surround the embryo 
more or less completely in many flowering plants. This tissue, 




THE WORK OF THE FLOWER 



41 



which is usually very richly supplied with accumulated foods, 
is known as the "endosperm" (Fig. 26). 

Maturation of the Seed. Embryo and endosperm (when 
present) continue to develop rather rapidly and with these 
activities come very profound changes in the ovule and the 
surrounding ovary. These changes culminate in the transforma- 
tion of the ovules into seeds and of the ovary into the fruit (Fig. 26). 
The micropyle is sealed by a plug of cork and the coats or 
integuments of the ovule harden, dry out, and in many cases 




FIG. 26. Diagrams to illustrate the sexual cycle in flowers. A, mature plant 
with flower; B to K, inclusive, structure of the ovary and stages in the develop- 
ment of the embryo sac and egg to the time of fertilization, O to V, inclusive, 
structure of the anther and development of the pollen grains to the formation 
of the pollen tube and sperms, L, pollen tube entering the nn'cropyle of the ovule; 
M , embryo that develops in the embryo sac by the growth of the fertilized egg, 
and seed developed by the transformation of the ovule, A 7 ", germination of tho 
seed. 

develop a very characteristic color, to remain as the seed coats. 
After a series of well-defined early growth stages the embryo 
becomes 4 clearly established structure with its root, stem, and 
leaves outlined and it comes to fill the cavity of the old embryo sac. 
In some cases the embryo uses the food furnished by the endo- 
sperm and surrounding nucellus to such a degree that little or no 
food remains so that the embryo practically fills the cavity inside 
the integuments. 

With the above significant activities completed the subsequent 
changes in the flower merely involve the maturation of seeds and 
fruit which introduces so many striking features that they may 
be treated more appropriately in a separate chapter. 



CHAPTER IV 
FRUITS AND SEEDS 

One series of floral activities comes to a close when the eggs in 
Howers are fertilized and another chain of important processes is 
initiated. These latter changes result in the transformation 
of ovaries into fruits and ovules into seeds, and each seed includes a 
partially developed new plantlet or embryo. We may now pro- 
ceed to inquire into the nature and behavior of fruits and seeds 
as important elements in the life histories of flowering plants. 

Secondary Effects of Fertilization. One of the remarkable 
consequences of sexual fertilization in flowers is seen in the second- 
ary effects of this process upon the future behavior of the ovary 
and its immediately surrounding structures. Fertilization 
(Pig. 26) normally results not only in the formation of the embryo, 
but also in the change of the ovule into a seed with its accumu- 
lated food, and the ripening of the ovary into the fruit. The 
ovary withers and dies as a rule if fertilization does not occur. 
It may be pointed out that the embryo would be quite helpless 
in most cases to develop a new individual in the absence of the 
secondary developments involved in the seed and fruit. These 
furnish the embryo with food and afford significant protection 
until environmental conditions render further development 
possible. 

FRUITS 

Definition of Fruits. The term "fruit" has a very much 
broader and more significant meaning in plants than is reflected 
in the popular use of the term in daily life. The botanist endeav- 
ors to base his concepts in this connection, as in the case of all 
other structures, on the point of view of the plant, so to speak. 
The development and structure of fruits may be understood best 
from a study of the flower parts from which they develop. The 
regular features of the ovary may be recognized in many mature 
fruits, even in such enormous ones as the coconut and watermelon. 
Among flowering plants, fruits are fundamentally the transformed 
and ripened ovaries of the flowers containing seeds. No other 

42 



FRUITS AND SEEDS 



43 



parts of the flower are associated with the fruit in the great 
majority of species, but in certain species some other portion 
of the flower, such as the receptacle (as in strawberry and apple) 
also feels the stimulus of fertilization to such a degree that it 
becomes greatly modified and may be inseparably associated 
with the mature fruit (Figs. 32 and 34). 

Popular Conceptions Are Misleading. Such a conception of 
fruits will at once include many structures not popularly known 
as fruits and exclude certain well-known structures commonly 
thought of as fruits. Botanically, a kernel of wheat or oats 
(Fig. 31, E), an acorn (Fig. 168), a sunflower "seed" (Fig. 27, E) 9 
a flaxseed pod, a tomato, and a peanut pod are true fruits, but 




A F 

FIG. 27. Dry fruits. A, a tailed achene of Pasque flower, Pulsatilla (after 
Le M . and Dec.); B, cluster of achencs of Adonis, Adonis (after Le M. and Dec.); 
C, achenes of water plantain, Ahsma (after Le M . and Dec.); I), single achene of 
buttercup, Ranunculus (after Le M. and Dec.); E, achene of sunflower, Helianthus 
(after Baillon); F, cluster of achenes of Clematis, Clematis (after Baillon); G, 
single achene of Adonis, Adonis (after Le M. and Dec.); H, achene of cornflower, 
Centaurea, with pappus (after Le M. and Dec.); I, ribbed seed of Escallonia 
(after Le M. and Dec.); J, achene of teasel, Dipsacus (after Baillon). 

such is not the popular conception. Popularly, a navel orange, 
a banana, and even a potato are known as fruits, but they 
certainly lack some of the regular features of fruits from the 
botanical point of view. The age-old attempt to distinguish 
between " fruits and vegetables 7 ' merely reflects the common 
fact that popular conceptions and definitions frequently cut 
across well-defined scientific knowledge and usage. 

Variations in Fruits. Fruits exhibit almost as great variety 
in size, color, shape, texture, number, duration, etc. as do flowers 
(Figs. 27, 28, 29, 30, 31, 32, 33 and 34). Some fruits are so 
small as to be scarcely visible to the unaided eye, but others 
are enormous things, perhaps more than a foot in diameter and 
weighing several pounds as in the coconut and the Jack fruit of 
tropical forests. 



44 



FLOWERS AND FLOWERING PLANTS 



Types of Fruits. The two broadest groups or types of fruits 
are fleshy fruits and dry fruits. Most fruits may be included in 
one or the other of these two types. Fleshy fruits (Figs. 32, 33 
and 34) are commonly very watery or juicy and more or less 
brightly colored. The colors of fleshy fruits usually contrast 
with their background, a feature which is significant with refer- 
ence to dissemination by animals. Dry fruits (Figs. 27, 28, 29, 
30 and 31), on the other hand, are usually gray, brown, or some 
other dull color and they do not contrast with their surroundings 
except in a few cases. Many shapes are seen in the fruits of 
flowering plants, but the form of the mature fruit is frequently 
that of the ovary. They often become greatly distorted, how- 
ever, by later growth and by the development of features that 




FIG. 28. Dry fruits. A, capsule of iris, Iris (after Le M. and Dec.); B, 
follicles of monkshood, Aconitum (after Le M. and Dec.); C, sihque of a mustard, 
Cheirima (after Le M. and Dec.}, D, capsule of waterlily, Nymphaea; E, capsule 
of poppy, Papaver (after Baillon); F, capsule of tobacco, Nicotiana (after Le M. 
and Dec.); G, silicie of shepherd's purse, Bursa (after Le M. and Dec.); H, opened 
capsule with cottony seeds of Cotton, Gossypium (after Baillori); I, utricle 
of amaranth, Amaranthus (after Le M. and Dec.). 

are not prominent in their youth. The many forms of crook- 
necked and scalloped squashes and the great variety of seed 
capsules are scarcely anticipated in the structure of the ovary 
at the time of fertilization. The ovary wall becomes very thin 
and dry in most dry fruits. In one-seeded dry fruits the ovary 
wall is so thin and it envelops the dry seed so tightly and conforms 
so closely with the shape of the seed that the whole passes as a 
"seed," as in sunflower, dandelion, buttercup, clematis, etc. 
(Fig. 27). The kernels of wheat, corn, and many other grasses 
are in reality dry, one-seeded fruits in which the ovary walls and 
seed coats are extremely thin, dry, and practically inseparable. 
The food in dry fruits is largely confined to the seeds. In 
fleshy fruits the ovary wall, or some part of it, as well as the 



FRUITS AND SEEDS 45 

internal tissues in many, become thickened but remain soft, 
fleshy, juicy, palatable, nutritious, and attractive. The food 
in fleshy fruits is largely accumulated in the thickened walls or 
partitions of the fruit, and the food within the seeds is commonly 
discarded or is in such small quantity as to be negligible from 
the standpoint of animal nutrition. The number of fruits 
produced varies greatly for different species but is likely to be 
determined in any given species by the age of the individual and 
environmental conditions. Likewise the duration of fruits is 
extremely variable, probably being longer in dry fruits as a class 
than in fleshy fruits. The very fleshiness of fleshy fruits contrib- 
utes (through more rapid decay) to thoir earlier disintegration. 

Number of Seeds in Fruits. Many fruits, especially dry 
fruits, and some fleshy fruits, produce a single seed, but many 
other dry fruits and fleshy fruits contain scores, hundreds, or 
even thousands of seeds. Dry fruits with a single seed are 
usually separated from the plant as a whole, the fruit functioning 
much as a single seed. But dry fruits with many seeds usually 
open at maturity to permit the escape of the seeds, and the 
empty fruits may remain on the plant indefinitely. Fleshy 
fruits normally remain closed at maturity whether they contain 
one or more seeds. The seeds of dry fruits are released from the 
fruit by propulsion or by the decay of the surrounding fleshy 
tissues, or by the digestion of those tissues within the bodies of 
animals that have eaten the fruits. 

Since fruits are very helpful in the classification of plants and 
in the delimitation of many of the families of flowering plants 
we should examine somewhat more closely the common varieties 
of dry and fleshy fruits. 

TYPES OF DRY FRUITS 

Dry fruits may be subdivided into two general groups depend- 
ing upon the number of seeds produced and whether the fruit 
opens naturally at maturity (dehiscent) or remains closed 
(indehiscent) . 

The Achene. The commonest type of one-seeded, indehiscent, 
dry fruit is the achene (Fig. 27), produced by the buttercup, 
strawberry, arrowhead, and the sunflowers and their kin. Func- 
tionally achenes are little more than seeds, although the thin, 
dry ovary wall which covers the single seed very closely may 
serve some useful purpose in certain cases. The fruit of clematis 



46 



FLOWERS AND FLOWERING PLANTS 



(Figs. 27, F, and 39, C) is essentially an achene in which the 
style persists and becomes greatly elongated and plumose. 
In many composites the vestigial calyx known as the pappus 
remains at the top of the achene as a whorl of papery scales, 
barbed bristles, or a tuft of long, silky hairs (Figs. 27, H and 
178, C and D) . In these forms, as in the clematis, these additional 
details are of great significance in connection with dissemination. 
The Samara. A samara is a dry, one-seeded, indehiscent fruit 
(Figs. 29, 38 and 166) in which portions of the outer wall of the 
ovary become extended to produce more or less prominent 

wings as in the elm, maple, and 
ash. Certain plants (Diptero- 
carpus y Rumex) produce a 
winged calyx which surrounds 
the fruit and serves much the 
same role as the wings formed 
from the ovary wall. 

Nuts and Nut-like Fruits. 
Nuts are rather complicated dry 
fruits, commonly with a single 
seed usually formed from an 
ovary with more than one carpel, 
(after Bail- and supplied with a variety of 

Lomatium (after Baillon); D, samara Coverings (Figs. 30, 33, 167 and 




D 

FIG. 29. Dry fruits. A, winged 
fruits of trce-of-Heaven, Ailanthus; 
B, samara of elm, Ulmut 



of Hiraea (after Le M. and Dec.); E, 
winged fruit of maple, Acer; F, lobed 
samara of Artcdia (after Kerner). 



168). The shell is usually quite 
hard and is more or less com- 
pletely overlaid with a covering 
which is hairy, scaly, fibrous, or almost as hard and resistant 
as the ovary wall (shell) itself. The acorn (Fig. 168) of an oak 
is a nut. which is partially enveloped by a cup formed at the base. 
The acorns of certain oaks and the nuts of hazel, beech, and 
chestnut are more nearly completely covered by a leafy or very 
rough or spiny coat corresponding to the acorn cup of the oak. 
The hull or husk of the walnut (Fig. 167), butternut, and hickory 
nut represent another type of covering in which flower parts 
other than the pistil take part. The husk of the coconut (Fig. 
30, A) is very thick and contains valuable fibers. The betel 
nut is the fruit of another palm resembling the coconut except 
that the husk is much more loose and open. The smooth, three- 
sided pili nut has an extremely thick and hard shell. Brazil 
nuts (Fig. 36, A) are the seeds of a large Amazonian tree in 



FRUITS AND SEEDS 



47 



which the fruit is a spherical or pear-shaped capsule 2 to 3 inches 
in diameter with a very hard woody wall. Each bears from 
12 to 30 "nuts" or seeds. 

Mericarp or Schizocarp. The characteristic paired fruit of the 
carrot and its relatives is known as a "mericarp" or "schizocarp" 
(Figs. 29, C, and 172). This is developed from a bicarpellary 
ovary in which the two opposite carpels develop into independent 
fruits, each bearing a single seed. Each of the one-seeded halves 
pulls away from the common axis between them. 




FIG. 30. Nuts and nut-liko fruits. A, coconut, Cocos, in the husk (after Le 
AF. and Dec.); B, end view of coconut with husk removed (after Le M. and Dec.); 
C, nut of chesnut, Castanea (after Le M. and Dec.); 7), fruit of nutmeg, Myristica, 
showing aril (after Baillon); E, female flower of Myristica with fruit developing 
(after Raillori). 



The Caryopsis or Grain. The fruit of most grasses including 
the cereals is peculiar and quite unique. This one-seeded fruit 
is known as a " grain or caryopsis," and it is characterized by 
such an intimate relationship and union between the inclosed 
seed and the enveloping ovary that the two are separated with 
difficulty, even with the aid of the microscope in following the 
development of the fruit from the ovary (Figs. 31, E, and 199). 
The caryopsis is little more than a seed for all practical purposes, 
though from the strictly botanical viewpoint it must be classified 
as a fruit, 

The Capsule. A capsule (Figs. 28, 31, 39, B, and 113) is a 
dry, dehiscent fruit developed from a compound ovary in which 
each carpel opens longitudinally along the carpellary septa 
(Azalea) or in the middle of the carpels (lily) or by pores toward 



48 



PLOWEKS AND FLOWERING PLANTS 



the top of each carpel (poppy). Each ripening carpel in the 
capsule produces several or many seeds, and as they ripen, the 
carpels tend to pull away from each other especially at the apex 
of the fruit. 

The Silique. The silique (Figs. 28, C and 121) is a several- 
seeded fruit developed in a bicarpellary ovary in which the two 
carpels pull away from the central partition or septum at matu- 
rity. This is the common type of fruit in the Cruciferae, or 
mustard family (Fig. 121). The common radish, Raphanus, is a 
familiar mustard in which this does not occur. The capsule or 
silique of this plant is indehiscent. 

The Legume. A legume (Fig. 31, C) is formed from a simple 
pistil and at maturity the fruit splits along two opposite longi- 




Fio. 31. Dry fruits. A, hooked capsule of unicorn plant, Martynia (after 
Le M. and Dec.}; B, tailed fruits of geranium, Geranium (after Bail Ion); C, 
legume of pea, Pisum (after Le Af. and Dec,); D, sectional view of mericarp of 
Lomatium (after BaiHon); E, grain of oat, Avena (after Bail I on); F, mericarp of 
caraway, Carum (after Baillori). 



tudinal sutures. This type of fruit is very common among the 
members of the bean and pea family which fact has led to 
the common name "legumes " being applied to that family. The 
legume in some species is curiously coiled, as in alfalfa or lucern, 
in some species of which the pod is so tightly coiled and so spiny 
as to resemble a bur. The legumes of certain tropical plants 
are very large and leathery or woody, 

The Loment. A lament is in reality a legume, but it is peculiar 
because it is usually very flat and tends to break up into sev- 
eral one-seeded segments. The surface of the segments in the 



FRUITS AND SEEDS 



49 



loments of some of our native American legumes (Meibomia) is 
covered by many low hooked hairs which make them very tena- 
ciously adherent to one's clothing if one brushes against the 
fruits in our prairies or woodlands. The relation of this feature 
to dissemination is obvious. 

The Follicle. A follicle (Fig. 28, B) is a dry, several-seeded 
fruit formed from a single carpel which splits along one side only. 
There may be two or more follicles produced from a single flower 
as in the milkweed, dogbane, larkspur, columbine, peony. The 
two follicles produced by each flower in the milkweed and dog- 
bane are formed from each of the two carpels in the bicarpellary 
ovary. 

TYPES OF FLESHY FRUITS 

Fleshy fruits (Figs. 32, 33 and 34) are all indehiscent. There 
are three general groups of fleshy fruits on the basis of the number 
of pistils or carpels represented, and the number of seeds pro- 




Fio. 32. Fleshy fruits. A, berry of belladonna, Atropa (after Le ^f. and 
Dec.); B, aggregate fruit, "berry," of raspberry, Rubus (after Baillon); C, similar 
fruit of strawberry, Fragaria (after Baillon); D, section of berry of coffee, Coffea 
(after Baillon); E, berry of Smilat (after Le M. and Dec.)-, F, cluster of berries of 
barberry, Berberia (after Batflon). 



duced. They all agree in the development of considerable 
fleshy tissue as the ovary or axis is changed into the fruit. 

The Drupe. A drupe ^Fig. 33, B and C) or "stone fruit " 
is formed from a simple pistil as a rule, or at least the fruit is 
typically single-celled, and it normally produces a single seed, 
though now and then a second seed is formed. The other com- 



50 



FLOWERS AND FLOWERING PLANTS 



mon features of a drupe include an exterior layer or pericarp 
of fleshy tissue, beneath which is a heavy stony layer or endocarp 
the "stone, " with the seed proper lying inside the stone or "pit. " 
The morphology of the layers varies somewhat for different 
drupes. The fruits of peaches, plums, cherries, olives, and 
apricots are the most familiar examples of drupes. The almond 
may perhaps be considered to be a drupe also, since it is fleshy 
like a peach until it is well grown, but it becomes dry as the seed 
matures and finally the covering (pericarp) splits open and the 
nut or "pit" is uncovered (Fig. 33, F). The part that is eaten 
in the almond is, of course, the seed. A coconut (Fig. 30, A and 
B) and a walnut (Fig. 167) have characteristics of a drupe, but 
in both of these the pericarp eventually becomes dry and fibrous. 




FIG. 33. Fleshy fruits. A, drupe of dogwood, Cornus; B, section of drupe of 
olive, Olea; C, section of drupe of cherry, Prunus; D, drupe of buckthorn, 
Rhamnus (after Baillori); E, leathery fruit of pomegranate, Punica (after Baillori), 
F t endocarp of peach, Amygdalus, laid open to show the seed; G, drupe-like fruit 
of Russian olive, Elaeagnus; H, fruit of pepper, Piper; /, fruit of -mangrove, 
Rhizophora, with seedling developing in situ (after Baillori). 



The Berry. Several kinds of fleshy fruits are developed from 
flowers with compound or polycarpellate pistils. A berry (Fig. 
32, A) is a fleshy, many-seeded fruit that is usually developed 
from a compound ovary in such a manner that the whole struc- 
ture has a very thin covering and is internally very fleshy and 
juicy and the seeds are imbedded in the common flesh of a single 
ovary. Illustrations of berries are seen in currants, gooseberries, 
cranberries, blueberries, guava, and tomatoes. 

The Pepo.-^-A pepo is a berry-like fruit of considerable size 
in which the outer wall of trie fruit is developed from the recep- 
tacle and this becomes toughish or very firm and hard. The 
internal structure of a pepo is commonly much like that of a 



FRUITS AND SEEDS 51 

berry. Common examples of the pepo are seen in the water- 
melon, cucumber, gourd, cantaloupe, pumpkin, and squash. 

Citrocarp or Hesperidium. The fruit of the orange, lemon, 
lime, and grapefruit (Fig. 34, C) is more or less berry-like inter- 
nally, but this type is usually given the separate designation 
"hesperidium. " The term "citrocarp" would be a good expres- 
sion for this type of fruit since hesperidium has a purely fanciful 
mythological origin. The thick, leathery rind beset with numer- 
ous oil glands, and the interior mass composed of several wedge- 
shaped locules, with or without seeds, are characteristic of this 
kind of fruit. 

The Pome. A pome is a fruit that is mostly fleshy throughout 
but it is developed largely from the cup-shaped receptacle which 
more or less completely surrounds the several carpels in the flower. 
Well-known examples of the pome are found in the fruits of apples, 
pears, and quinces. The flesh of the ripe apple consists very 
largely of the greatly thickened cortex of the floral axis or recep- 
tacle ("calyx cup") and the pith of the receptacle. The five 
carpels with their smooth, parchment-like compartments occupy 
the central position and make up, with certain other structures, 
what is known as the "core" of the apple. That is, the "core" 
really contains the ripened pistils, but in this case they are not 
included in the popular conception of a fruit, at least they are 
not eaten, unless perchance one is very hungry. 

Aggregate and Accessory Fruits. A third general class of 
fleshy fruits are very peculiar in their morphological composition 
because of the interrelationship between the receptacle and ovary 
and the excessive development of the receptacle. As a rule 
many ovaries and many seeds are involved in the development 
of these fruits and in some of them several to many distinct 
flowers are represented in the finished fruits. 

An aggregate fruit is a fleshy structure developed by the single 
receptacle of a single flower, but the receptacle becomes more 
or less enlarged and bears many simple, true fruits of the nature 
of achenes or drupes. This fruit is derived from a single flower 
with many separate pistils, as in the custard apple (Anona), 
strawberry, blackberry, loganberry, and dewberry (Figs. 32 and 
34). The fruit of a strawberry (Fig. 32, (7) is composed of an 
enormously enlarged receptacle, more or less uniformly dotted 
with numerous widely separated achenes. The true fruits here 
are the achenes, but the edible portion is the axis, the true 



52 



FWWEHN AND FLOWERING PLANTS 



fruits being eaten as a rule as "seeds" because it is a nuisance 
to remove them. Some writers have made the strawberry the 
type of another class of fruits called "accessory fruits, " because of 
the dominant part played by the axis in the ripe structure. In 
the blackberry (Fig. 32, ), dewberry, and loganberry the 
receptacle does not develop to such a degree as in the strawberry, 
but the many individual carpels enlarge and are transformed 
into " drupelets" exactly like so many diminutive cherries clinging 
to the receptacle. Here we have an aggregate of fruits which 
together make up the major volume of edible material in these 
fruits. These drupolets are directly comparable to the achenes 
(or "seeds") of the strawberry. The raspberry presents another 




FIG. 34.- A, vertical section of the fruit of fig, Ficua (after Baillori), B, vertical 
section of the fruit of custard apple, Anona (after Baillori); C, transverse section 
of fruit of orange, Citrus (after Le M. and Dec.) 



difference in that the cluster of drupelets separate from the 
receptacle when mature, so that the ripe "berry," consisting of 
a cup-shaped cluster of drupelets may be lifted off from the dome- 
like receptacle. In the strawberry it is the large fleshy axis or 
receptacle that contributes the food, and the true fruits or achenes 
("seeds ") are eaten because they cannot be readily avoided; 
in the blackberry, dewberry, and loganberry the important 
edible part is the cluster of drupelets or true fruits, the axis being 
relatively small and unimportant; in the raspberry only the 
aggregation of druplets or true fruits are eaten, since the recepta- 
cle remains on the bush when the berries are picked. Thus we 
see that these so-called "berries" are structures really very 
different from true berries in the botanical sense. 



FRUITS AND SEEDS 53 

Multiple Fruits. Multiple fruits in contrast to aggregate 
fruits are formed from the ovaries of many separate closely 
clustered flowers, or, in other words, these fruits are derived 
from a cluster of flowers instead of from a single flower. 
Examples of multiple fruits are seen in the mulberry and pine- 
apple. In the mulberry the clusters of pistillate flowers are 
separate from the staminate flowers, and they are crowded very 
closely together. Each of these flowers has a single, one-celled 
ovary enclosed by a thick, fleshy calyx of four sepals. After 
fertilization the sepals close over the ovaries, each unit becomes 
increasingly fleshy and enlarged and more or less united to 
its neighbors to form the "berry. " The ripe pineapple is 
also a cluster of fruits formed by single separate flowers densely 
clustered on a central axis. The floral bracts and other 
flower parts become fleshy and greatly enlarged and consolidated 
into what appears to be a single unit structure at maturity, quite 
misleading as to its proper morphological interpretation. 

The Fruit of the Fig. The fig (Fig. 34, A) produces another 
peculiar type of fruit in which many flowers are involved. The 
fig is in reality a hollowed-out receptacle with a lining of numerous, 
tiny, separate flowers. Pistillate and staminate flowers may be 
mingled together within the same receptacle or, in some species, 
they are produced by different receptacles. Each pistillate flower 
has a simple pistil and little or no perianth. After fertilization 
this ovary develops into a nutlet with a single seed and the 
v hole structure becomes more or less imbedded in the wall of the 
enlarged and very fleshy or gelatinous receptacle. This curious 
thing has been called a "syconium." The ripe fig consists 
of the enlarged, fleshy receptacle which encloses many nutlets 
("seeds") produced by the pistillate flowers which line the 
cavity of the receptacle (Fig. 34, A). Here again is a fruit in 
which the receptacle constitutes the major portion of the fruit. 

The various types of fruits considered in this chapter may be 
brought together in tabular form as follows: 



54 



FLOWERS AND FLOWERING PLANTS 



Dry Fruits 



Fleshy Fruits 



One-seeded, indehiscent 



Many-seeded, dehiscent 



Pistil mostly simple and one- 
seeded 



Pistil compound, but single 
flower. Seeds many 



Pistils many from one or 
many flowers. Seeds many 



TABULAR SUMMARY OF FRUITS 



Achene 

Samara 

Nut 

Schizocarp 

Caryopsis 

Capsule 

Silique 

Legume 

Loment 

Follicle 

Drupe 

Berry 
Pepo 
Pome 
Hesperidiun 

Aggregate 
Accessory 
Multiple 
Syconium 



FRUITS AND SEEDS 55 

SEEDS 

Some additional features of seeds as developed by flowering 
plants will now be considered. 

The great variation in detail that the seeds of different flower- 
ing plants reveal is perhaps surprising when it is recalled that 
they are formed within the ovary under conditions that appear 
to be quite uniform. So characteristic are seeds that they are 
very useful agents in the classification of plants. Indeed, many 
species of flowering plants produce seeds that are so strikingly 
characteristic as in themselves to furnish an absolutely infallible 
clue to the identity of the species or variety. Plants that are, 
superficially, very similar often produce seeds that are strikingly 
different. And, on the other hand, seeds that are closely similar 
may be produced by plants that are very different, as in the 
dodder and alfalfa. Federal and state seed experts utilize 
such facts in the detection and measurement of impurities 
(foreign seeds) in commercial seeds. 

The Origin and Nature of Seeds. A seed is produced as a 
result of the fertilization of an egg within the embryo sac of an 
ovule (Figs. 25 and 26), which, in turn, is attached at some point 
inside the ovary of the flower. There may be as many seeds 
matured as there are ovules, but that probably seldom happens. 
The difficulties surrounding pollination and fertilization interfere 
to prevent the development of so large a proportion of the ovules 
into seeds. There are scores of ovules in the common commercial 
banana ovary and there are hundreds or even thousands of them 
in the ovary of flowers of many orchids but none of these ovules 
may develop seeds at all. A certain orchid, Maxillaria, produces 
as many as 1,750,000 seeds in the ovary of a single flower. In 
the cherry and almond there are usually two ovules in the ovary. 
Only one of them, however, regularly develops into a seed, though 
now and then both form seeds. 

Seeds are usually relatively small structures when they are 
mature and become separated from the parent plant. Never- 
theless, they may carry a living embryo for great distances and 
under proper conditions they may give rise to a new individual 
far from the plant that produced them. Man finds in seeds a 
very convenient form in which to transport plants from one 
area of the world to another. f 

Physical Features of Seeds. The size, shape, texture, color 
and longevity of seeds are a%$ariable as flowers (Figs. 35, 36, 



56 



FLOWERS AND FLOWERING PLANTS 



and 37). Certain tropical orchids produce seeds that are as 
fine as dust, whereas in the coconut the seed may be several 
inches in diameter. Although we have a generalized conception 
of the shape of seeds few of us are aware of the multitude of 
variations in form and surface features that are to be seen in seeds. 
Typically more or less globular or oval, they range in form to 
extremely thin and flat, or greatly elongated, smooth, wrinkled, 
pitted, angled, furrowed, twisted, coiled, or irregularly distorted, 
and often more or less covered with hairs as in cotton, Gossyp- 
ium, milkweed, Asdepias, or supplied with broad and extremely 
delicate, membranous wings as in Pithecoctenium (Figs. 35, 36, 
and 37). Seeds are typically very firm and hard when ripe, 




FIG. 35. Seeds. A, flat seed of moon wort, Lunaria (after Le M. and Dec.); 
B, walnut, Juglans; C, lamb's quarters, Chcnopodium; D, beet, Beta; E, Russian 
olive Elaeagnus; F and G, winged seed of Spergularia (after Le M. and Dec.); 
H, fleshy seed of pomegranate, Punica; /, bouncing bet, Saponana; J, section 
of same; K, iris, Iris; L, spiderwort, Trade^cantia (after Le Jlf. and Dec.), M, 
section of achene of cornflower, Centaurea, showing the single seed within, A' 
and 0, baby's, breath, Gypsophila. 

but they may become very soft during the germination period. 
The seeds of a tropical South American palm, Phytelephas, 
furnish the " vegetable ivory" of commerce, and are used in 
making buttons. 

Significance of Colors in Seeds. The variety of coloring and 
color patterns are perhaps the most conspicuous external differ- 
entiation that seeds show. Nearly every color known can be 
matched in seeds from shining jet 'black to less somber 
brown and gray to peculiarly striking bright blue, yellow, red, 
scarlet, etc. The mingling or mottling of colors and tints is 
also a noteworthy feature of many seeds. As in fruits the gay 
colors are to be associated with very different possibilities of 
dissemination than is true for the more somber or dull-colored 



FRUITS AND SEEDS 57 

seeds. Seeds and fruits that are scattered by wind or water 
are usually inconspicuously colored, but the bright and showy 
seeds and fruits more commonly appeal to animal agents of 
migration. 

Seeds and Fruits Often Confused. Seeds and some of the 
smaller fruits are not always readily distinguished. This is 
particularly true for the dry one-seeded fruits such as achenes 
(Fig. 27), which for all practical purposes are in reality seeds. 
The possible confusion in this regard with reference to the 
morphology of the grains of corn, wheat, and other grasses has 
already been pointed out. The use of the term "seed" by the 
practical grower of plants carries with it the thought that an 
essential item of the most common and useful methods of plant 
propagation involve the presence of true seeds, whatever may be 
the nature of associated structures. Onion seed and turnip seed 
in the everyday sense are also seed in the botanical sense. Seed 
corn and seed wheat as used in ordinary agricultural parlance 
are in reality true fruits (caryopses) of a highly specialized type. 
Seed oats and seed barley frequently are even more than seeds 
and fruits, for in many varieties of these common crops the old 
dry scales (flowering glumes and palets) of the flowers have 
persisted and completely surround the grain as the "husk." 
Potato "seed" is almost invariably composed of tubers or sub- 
divisions of tubers that are planted in the soil. Few people have 
ever seen the true fruits and seeds of the Irish potato. The 
fruits ("fruit balls") are much like diminutive tomatoes (berries) 
produced by potato flowers in the usual way and bearing many 
seeds. These are not used at all in the regular production of 
our great crops of potatoes. The "seed" so-called of sweet 
potato is composed of roots or sections of the roots' of this plant. 
The true seeds of the sweet potato are produced in a capsule 
much like that of an ordinary morning-glory. The sweet potato 
is, indeed, a species of true morning-glory. 

There are also numerous true seeds that are not popularly 
regarded as seeds. Thus the kernels of nuts such as walnuts, 
pecans, almonds (Figs. ^5, B and 36, A), etc., are true seeds, as 
are "peanuts," beans, and peas (Fig. 31, C), although these are 
not commonly regarded as such. 

Distinguishing Features of Seeds. Botanically, true seeds 
possess certain regular features which become their distinguishing 
characteristics. The embryo plant inside is the most important 



58 



FLOWERS AND FLOWERING PLANTS 



constituent of a seed. This is merely a new living plant whose 
growth has been suspended for a time by conditions attendant 
to the ripening of fruit and seed. This embryo always has 
a central axis or stem called the "hypocotyl," bearing at one 
end the embryonic root or radicle, and at the other end the 
rudiments of a bud. The seeds of some plants produce embryos 
so large that this bud becomes so well developed as to produce a 
distinctly leaf -like structure called the "plumule." The cotyle- 
dons or "seed leaves" are attached to the stem at some distance 
below the terminal bud or plumule. Most flowering plants 
(Dicotyledons) produce two opposite cotyledons, and in some of 
these the cotyledons are more or less distinctly leaf-like, but in 
most species they are decidedly lacking in the typical features of 




Fio. 36. Seeds. A, single seed from the fruit of Brazilnut, Berthoh-ttia; 
B, moonseed, Menispermum; C, transverse section of horny seed of date, Phoenix; 
D, surface view of seed of Phoenix; E, chocolate, Theobroma; F, Kentucky 
coffetree, Gymrwdadus. 

leaves. The cotyledons are frequently crowded out of the seed 
along with radicle, hypocotyl, and plumule, at the time of 
germination and actually reach above the surface of the ground 
where they develop chlorophyll and function as true leaves. 
In many other flowering plants especially in the grasses (Mono- 
cotyledons) the situation with reference to the cotyledons is 
quite different. The seeds of corn or wheat, for instance, show 
an embryo with hypocotyl, radicle, and plumule, but there is a 
single lateral cotyledon. This cotyledon is scarcely at all leaf -like, 
never being pushed outside the seed during germination and 
developing chlorophyll, but remaining within the seed and 
functioning as a digestive organ for the embryo. Such a cotyle- 
don is known as the scutellum. 

Seeds with Several Embryos. Seeds normally contain but a 
single embryo. A number of flowering plants, however, produce 



FRUITS AND SEEDS 59 

seeds with more than one embryo. Thus certain members of 
the citrus or orange group, particularly the grapefruit, Citrus 
grandis, frequently show this condition. One sometimes finds 
several seeds with more than one embryo in a single grapefruit. 
If all of the seeds of a series of grapefruits are germinated (very 
easily accomplished) one will almost invariably secure a larger 
number of seedlings from the fruits than there were seeds in the 
respective fruits. The extra embryos in seeds have diverse 
origin, from nucellar buds, and possibly from multiple embryo 
sacs within a given nucellus. The phenomenon of polyembryony 
is doubtless more interesting than significant, because it is too 
rare to be of any great value as a supplement to normal 
reproduction. 

Foods and Other Materials in Seeds. Another important 
item in the makeup of seeds is the food which was accumulated 
in the seed before it was cut off from the parent plant. The 
three classes of foods: carbohydrates, including sugars, starches, 
and celluloses; proteins; and fats, including rather heavy nitrog- 
enous foods as well as heavy and lighter oils, are included in 
greater or less quantities in practically all seeds. The seeds of 
certain species, such as beans, buckwheat, and cereals, such as 
maize, wheat, rice, are rich in starch; in others, such as peanuts, 
walnuts, Brazil nuts, castor beans, flax, coconut, and cotton 
there is a relatively high* proportion of fats; and in others, such 
as beans and peas, there is a considerable quantity of protein. 
The seeds of certain species, notably asparagus, coffee, datepalm, 
and vegetable ivory, contain massive tissues in which the cell 
walls become enormously thickened by the accumulation of 
secondary cellulose (hemicellulose) which also serves as food 
for the embryo during the period of germination (Fig. 36, C). 
The seeds of the vegetable ivorypalm produce large masses of an 
exceedingly hard, bony tissue of this sort that is used commerci- 
ally in the manufacture of "pearl" buttons, knife handles, etc. 

Value of Foods in Seeds. The presence of quantities of food 
is of inestimable value not only to the plant, for which they are 
produced, but also to man, who long ago learned to use such 
objects as sources of essential food supplies for his own mainte- 
nance. Amazing quantities of seeds are used as food for man 
and beast each year. 

Localization of the Food in Seeds. The foods accumulated 
within seeds are mostly collected in one or the other of two differ- 



60 FLOWERS AND FLOWERING PLANTS 

ent portions of the seeds. In one case the food is largely confined 
to the cells of the embryo itself, and the embiyo practically fills 
the cavity of the seed (Fig. 35, /). This type of food accumula- 
tion is illustrated by the seeds of peanut, bean, pea, clover, alfalfa, 
apple, oak, hickory, and almond. Many other species use the 
persistent endosperm as a storehouse for the food, as in corn, 
wheat, and other cereals, castorbean, and morning-glory. The 
endosperm, more or less heavily packed with the food, closely 
envelops the embryo (Fig. 35, K) and fills in the space between 
the latter and the covering of the seed. The origin of the 
endosperm from the fusion of the second sperm with the equa- 
torial nucleus of the embryo sac at the time of fertilization has 
been described. Seeds with endosperm supplied with foods have 
been called " albuminous " seeds, and seeds with little or no 
endosperm, but with the foods contained by the embryo have 
been termed "exalbuminous" seeds. The tissue with such strik- 
ing features as noted for the ivorypalm, date, asparagus, etc. is 
really endosperm, and the hemicellulose accumulated therein 
surrounds the embryo very closely. Nevertheless, the embryo 
of such plants is equipped to digest the food represented in those 
thickened cell walls and so to utilize it during germination, in 
much the same manner in which the more common foods of other 
seeds are transformed and assimilated by the growing embryo. 

Covering of Seeds. The seed coats constitute the covering 
of the seed. These are usually the transformed integument or 
integuments (Figs. 23 and 25) of the ovule. As the ovule 
gradually changes into the seed the integuments become thick- 
ened, and hardened, sometimes becoming exceedingly tough, 
hard, and woody, so that the living embryo is enclosed by a 
very resistant^ protective covering. The value of such a condi- 
tion, so common among seed plants, must be obvious when we 
recall the fact that the embryo is a very delicate, living thing 
and that it is finally separated completely from the body of the 
parent. Not only that, it may also be placed in very unfavorable 
and dangerous conditions so that it would surely perish if it were 
not for the effective protection afforded by the seed coats. 

The Inner Coat. Besides the thick outer seed coat or testa of 
major importance, certain seeds also have an inner, membranous 
coat which immediately^ invests the embryo or the endosperm 
and embryo. The seeds of a few species, as waterlily and certain 
sedges produce an aril, or a loose and more or less baggy, air- 



FRUITS AND SEEDS 61 

containing, membranous modification of the outer coat which 
aids in dispersal. 

Further Details of Seeds. Mature seeds exhibit a great 
variety of surface markings (Figs. 35 and 36) and configurations 
as has already been mentioned, but they all agree in showing a 
minute pore or pit that marks the position of the micropyle of 
the ovule which became sealed as the seed matured The hilum 
is the scar left on the spot where the seed separated from its 
attachment in the ovary. Seeds that have been formed from 
inverted ovules (Fig. 23), as in the pansy, sometimes show the 
ridge along one side extending nearly from one end to the other 
formed by the ovulary stalk (funiculus) which becomes grown 
to the side of the ovule. This ridge is called the "raphe." 

Behavior of Ripe Seeds. Vital activity in seeds is at a very 
low ebb at the time the seeds are ripe or when they are freed 
from the parent plant. This is of great value since the embryo 
is very delicate and is quite likely to be severely injured if it 
were to continue growth under the varied conditions into which 
seeds go. A noteworthy exception to this general rule is in the 
mangrove, Rhizophora, (Fig. 33, /), in which the embryo continues 
its development without cessation until a good-sized seedling is 
developed in position upon the axis of the flower. The new 
plant is often a foot or more long before it drops from the parent 
plant. This is a phenomenon that closely compares with vivip- 
ary in mammals. 

Delayed Germination of Seeds. Suppression of activities 
inside the seed during dissemination and for long periods there- 
after in many cases appears to be related to the dryness of the 
tissues of the ripe seed. The phenomenon of delayed germination 
is also of tremendous value to the plant in meeting the vicissitudes 
of an environment that is likely to be very uncongenial to flower- 
ing plant activities for considerable periods of time. Seeds that 
show these characteristics, and seeds that are capable of retaining 
their vitality for long periods, even under conditions of stress, 
are likely to be the most successful as organs of maintenance for 
the species concerned. 



CHAPTER V 
HOW FLOWERING PLANTS TRAVEL 

One of the noticeable tendencies of flowering plant species is 
to move about from place to place over the earth. A given 
species may disappear from an area for a time and then reappear 
at some later date, and a strange species may suddenly become 
more or less prominent in a region where it had previously been 
unknown. The phenomenon of the movement or migration of 
plants through narrow or extensive limits is an observation 
common to almost everyone. Herein lies one of the most 
dynamic of all of the processes that together constitute the 
active phases of the life cycle of flowering plants. 

NATURE OF PLANT MIGRATION 

Migration is commonly understood to include all types and 
degrees of movement that tend to carry plants away from a 
parent individual or outward from an established center. Ordi- 
narily we may and should distinguish between migration, as the 
movement of plants, and establishment, which may or may not 
follow the movement. Migration and establishment are obvi- 
ously two very different biological processes. 

Freedom of Movement. The relative freedom of movement 
or locomotion of individual animals as compared with individual 
plants is one of the few significant differences between animals 
and plants. And yet many species of plants are capable of 
quickly spreading their individuals over wide areas. Plants in 
general are compelled to equip themselves for moving about in 
order to reduce the population pressure, an environmental 
relation that is ajso conspicuous among animals, So we must 
conclude that migration is a biological necessity for plants as 
well as for animals. 

Capacity for Migration. An important factor affecting plant 
migration is the capacity of the plant to migrate. This capacity 
is expressed in plant ecology by the term " mobility." The 
degree of mobility is largely determined by the efficiency of 

62 



HOW FLOWERING PLANTS TRAVEL 



63 



structural modifications as acted upon by the various factors of 
the environment. We say that the mobility of flowering plants 
with large, heavy fruits or seeds is low, but in species with tiny, 
light fruits or seeds equipped with wings or tufts of hairs that 
catch the wind, mobility is high. 




FIG. 37. Seeds. A, the seed of Pithecoctenium with a very broad membranous 
wing; B, seed of cotton, Gossypium; C t seed of milkweed, Asclepias. 

Aids to Migration. The structural modifications in flowering 
plants related to migration are very numerous and varied. Most 
of such modifications affect only the fruits or seeds, but other 
parts of the plant are occasionally utilized for these purposes. 
The numerous anatomical details of flowering plants that are 
of value to the species through their relation to dispersal or 
migration may now be roughly classified and described. This 
discussion will deal first with fruits and seeds as related to 
migration. Our classification is based primarily on the agent, 
factor, or force concerned with or operating upon the disseminules. 

FACTORS IN MIGRATION 

Wind. Wind is one of the most impressive and effective 
factors in the migration of flowering plants. The modifications 
of the fruit or seed that favor dispersal by the utilization of wind 
or air currents are numerous. Certain of these are provided with 
wings that are more or less membranous, Here we have maple, 
ash, elm, birch, certain members of the carrot and grass family, 
etc. in which the wings are a portion of the fruit (Figs. 28, G, 
and 29), and Catalpa, Bignonia, trumpet vine, etc., in which 
the wing is a part of the seed. Other fruits or seeds are supplied 
with long silky or woolly hairs. Examples of this type are seen 
in anemone and Clematis, in certain species of which the fruits 
(achenes) are more or less covered by the hairs, and in willow, 
cottonwood, aspen, cotton, milkweed, willowherb, in which the 



64 FLOWERS AND FLOWERING PLANTS 

seed is the part modified for dispersal by wind (Figs. 37, A, B, C). 
Fruits with long plumose style, with high degree of mobility, 
are seen in Clematis (Fig. 39, C), Pasque flower, alpine Sieversia, 
and others. Fruits with parachute-like tufts of hairs, with exceed- 
ingly high mobility, are illustrated by dandelion, lettuce, salsify, 
and many other composites (Fig. 38, A, B). Fruits with a 
membranous sac-like envelope formed from the ovary or calyx are 
developed in hop hornbeam, bladdernut, ground cherry, etc. 




FIG. 38. Types of disscminules. A, in dandelion, Taraxacum, B, in ironweed, 
Vernonia; C, in maple, Acer; D, in valerian, Valeriana; E, in Brunonia; F, m 
tree-of-Hoaven, AHanthiis. 

Animals. Animals of great variety also assist in many ways 
to distribute plants. The more common modifications oiP fruits 
or seeds may be noted in this connection. Fruits with hooks 
or barbs that attach the parts to passing animals are numerous. 
(Figs. 38, E and 39, A and D.) The Degree of mobility in these 
cases is very high as a rule. Illustrations are afforded by cockle- 
bur, bedstraw, Spanish needles, wild liquorice, agrimony, avens, 
Lespedeza, unicorn plant (Fig. 31, A), etc. The burdock may be 
included here als6, but in this plant the hooks are at the tips of 
the involucral bracts that surround the head of flowers. Fruits 
with awns or beards that are needle-like or very rough or hairy 
so that they cling to the fur or feathers of passing animals are 
developed in many species. Many grasses are included in this 
group, notably porcupine or needle grass (Fig. 199, F), triple- 
awned grass, wild barley, June grass (Bromus), etc., other fruits 
are provided with spines developed on the surface, as in sandbur, 
and puncture weed (Tribulus). Still other fruits or seeds are 
fleshy and are eaten by birds and other animals and may be 
carried in large numbers for great distances (Figs. 32 and 33). 
Here we have many species with various types of fleshy fruits 



HOW FLOWERING PLANTS TRAVEL 65 

such as drupes in the cherries, berries in great numbers, pomes in 
haws, etc. The seeds in such fruits are usually protected by a 
stony envelope ("pit") or seed coat so that they resist the 
destructive action of the animal's digestive system and they are 
usually regurgitated or discharged with the excrement unharmed 
(Fig. 33, C). Fruits or seeds of other species are covered with 
adherent glandular hairs or viscid secretions, as in the chickweeds, 
sages, catchflies. Nuts and nut-like fruits and seeds are also 
carried away by certain animals, especially rodents, and in this 
way such plants as hickory, walnut, and beech are scattered. 

Plants are also scattered far and wide by man, often without 
relation to the natural mobility of the plant. Thus a person 
may carry large, heavy seeds or fruits half-way around the world 
and grow the plants in a place where the species might never 
have occurred without man's help. Man may also carry plants 
unintentionally as is often done. Man may affect great move- 
ments of plants through distances and in a very short time in 
a manner that is wholly impossible with any other agent of 
migration. Many undesirable weeds and other plants have 
been brought into a country by travelers from foreign lands. 

Water. Certain plants are able to migrate by means of 
water in the form of tides, ocean currents, streams or surface 
flow in lakes or on the land. There are two principal types of 
structures that make this kmd of migration possible, the best 
known example of which is*the case of the coconut. The thick, 
fibrous husk of the coconut (Fig. 30, A) coupled with the very 
hard shell of the "nut" (Fig. 30, B) render the structure practi- 
cally impervious to water so that these fruits have been known 
to drift for long distances in the sea. The impervious or air- 
containing fruits of certain sedges and waterlilies adapt these to 
flotation on the water also. Surface run-off also affects consider- 
able movement of seeds and fruits that lie upon the ground, but 
there is no particular morphological feature of the propagules 
related to this type of water influence, although many seeds 
and fruits that are scattered in this manner are buoyant. 

Gravity and Glaciers. The force of gravity and glacier 
movement are of some importance in migration in mountainous 
areas and in the Arctic and Antarctic regions. The significance 
of glacial action as related to plant migration in the past can 
hardly be overemphasized, but glaciers play only a local and 
relatively insignificant r61e in migration today. 



66 



FLOWERS AND FLOWEHING PLANTS 



MODIFICATIONS OF THE PLANT 



Explosive Fruits. The fruits of some plants are more or less 
explosive when ripe and this phenomenon serves to scatter the 
seeds. The distance to which the seeds are propelled may not 
be very great in any one season, but the effect becomes of impor- 
tance when continued through the years. Several different 
mechanisms are involved in explosive fruits, but they mostly 
agree in the sudden release of pressure of sufficient magnitude to 
disrupt the fruit and send the seeds flying. Some of these 
fruits are said to burst with a report like a pistol shot, as in the 
"sand-box tree" of the West Indies. In some cases the sudden 
and forcible collapse of the fruit with the discharge of the seeds 




FIQ. 39. Other types of disseminules. A, Kramcna; B, violet, Viola; C, 
clematis, Clematis; D, avons, Geum; E, sorrel, Oxalis. 

is due to a drying out of different layers of the ovary wall at 
different rates thus developing counter strains in the tissues 
to such a degree that certain layers are suddenly overcome. 
Some such conditions as these obtain in the fruits of the violet 
(Fig. 39, B), certain vetches, Oxalis (Fig. 39, E), castor bean and 
witchhazel (Fig. 150, C and D), resulting in the sudden ejection 
of the seeds. The seeds of the witchhazel may be fired as far as 
10 feet away from the capsules in which they are formed. The 
origin of the tension differences in other fruits is found in the 
osmotic pressure of the ripening tissues in the walls of the fruits 
or seeds, as in the common " touch-me-not " (Fig. 115) of our 
woodlands, and the so-called squirting cucumber, Ecballiurfi, of 
the Mediterranean basin. The fruit in the latter plant is like a 
small fleshy cucumber with a bristly surface. The stalk of the 
fruit is hooked and it projects for some distance into the end 
of the fruit. As the fruit ripens the interior mass containing 
the seeds becomes gelatinous and the tissues adjacent to the 
base of the stopper-like stalk become weakened. The tissues in 



HOW FLOWERING PLANTS TRAVEL 67 

the wall of the fruit develop great tensions and become dis- 
tended. The principal focus of this pressure is directed toward 
the gradually weakening tissues about the base of the stalk. 
At a certain point in the ripening process the pressure overcomes 
the resistance of the tissues in an annular zone about the stalk, 
resulting in the sudden forcing of the stalk outward; the dis- 
tended walls contract and much of the juicy, mucilaginous 
contents of the cucumber, including the seeds, are squirted out 
through the hole. 

Vegetative Modifications. The fruit and seed arc the most 
common, varied, and useful features of the plant as related to 
migration, but certain plants utilize certain vegetative pecu- 
liarities to an effective degree in this connection. 

Tumbleweeds. The form of the entire aerial portion of the 
plant in certain species contributes in a very important degree 
to the mobility of the species. This is the case in those plants 
that are commonly known as "tumbleweeds " as represented by 
Russian thistle (Salsola), Cycloloma, etc. in which the bushy plant 
breaks off at or near the surface of the ground and may be 
rolled along for long distances in open windy regions. As a rule 
such plants carry many fruits and seeds that are sown as the bushy 
structure tumbles along. The finely branched panicles of many 
grasses and fragments of other species may be distributed in this 
same manner. Large portions or fragments such as winter buds 
of paludose or submerged plants bearing seeds or otherwise 
capable of establishing themselves are distributed by means of 
water as in the frogbit, pondweeds, etc. 

Offshoots. The most common vegetative structures for 
migration are of the nature of offshoots of considerable variety of 
form and effectiveness. These are usually modifications of 
some regular organ of the body such as a stem, root, or 
leaf which stretches away from the parent body and "strikes 
root" in such a manner as to establish a potentially new indi- 
vidual. The connection with the parent may be completely 
broken later. Many species that propagate in this manner 
may show many series of these offsets or "new generations" 
still linked with the original individual. 

The most numerous modifications of this sort are stems, 
morphologically, although because of their common subterranean 
position they are popularly regarded as roots. Such structures 
are even sometimes much more like roots than stems in their 



68 



FLOWERS AND FLOWERING PLANTS 



superficial characteristics, but they are ordinarily easily classed 
with stems upon the basis of their finer structure and morphology. 
There are also numerous species which produce aerial vegetative 
stems that are admirably adapted to migration and asexual 
propagation. 

The Rhizome. Rhizomes are usually slender, greatly elongated, 
more or less horizontal underground sterns with scattered scales 
or scale-like leaves at the nodes, and lateral and terminal buds 
(Figs. 40, 41 and 42). Erect branches which emerge and develop 





FIG. 40. Thick rhi- 
zome of iris, 7m (after 



FIG. 41.- Slender rhizomes of quack grass, Agra- 
pyron. A, young growth with new shoots, B, older 
plant (after Mathcti^) 



the aerial portions of the plant are formed from lateral buds, 
but many such branches die back each year in numerous temper- 
ate climate species. Rhizomes remain alive in the soil and they 
form new lateral and terminal buds from year to year as well 
as lateral branches and thus serve to carry each new generation 
farther and farther away from the parent with which they may 
maintain an indefinite continuity. In this manner, the soil in 
the general level at which this rhizome complex develops 
may be so permeated with rhizomes and roots arising therefrom 
as to resist vigorous wind or wave action. 

Many species of flowering plants develop rhizomes, among 
them being 7m (Fig. 40), cattail, pondweed, banana, Canada 
thistle, bindweed, morning-glory, Solomon's seal, peppermint 
(Fig. 42), and many grasses such as sugar cane, Johnson grass, 
quackgrass (Fig. 41, B) and marrowgrass. This method of 




HOW FLOWERING PLANTS TRAVEL 69 

migration and propagation is the outstanding feature of the 
behavior of the sand-binding grasses and other plants of sand 
dunes and other shifting soils. Rhizomes are sometimes called 
rootstocks, the two terms being essentially synonymous. 

Tubers. Tubers are shortened, greatly thickened, more or 
less fleshy segments of underground stems in which the usual 
stem characteristics are even more completely suppressed or 
masked than is the case in rhizomes. Many species produce 
tubers, among which may be mentioned Irish potato, wild pea 
(Apios), sunflower or Jerusalem artichoke, Begonia, and ele- 
phant's ears (Colocasia). The tuber may form at the end of a 
slender rhizome-like stem, as in the Irish potato, or there may 
be a series of bead-like tubers arranged at intervals along the 
stem as in Apios. There is 
usually a terminal bud or 
cluster of buds at the outer 
end of a terminal tuber, and 
there are also many buds scat- 
tered over the surface or im- FlG - f 42 RhomcB of peppermint, 

Mcntha ptpcrHa (after Mathews). 

bedded beneath the surface of 

the tuber. The "eyes" of a potato are in reality buds with 
reduced scales and little external evidence of their true nature. 
Since the eyes are buds that represent the outer tips of potential 
lateral branches one can readily understand the necessity of 
having at least one "eye" on each seed piece when potatoes 
are planted. The true structure and morphology of these strik- 
ingly modified sterns may be determined only by tracing their 
development or by means of a careful anatomical examination of 
the mature tubers. The practical value of tubers and rhizomes to 
mankind in plant culture cannot be overestimated. 

Corms. Corms (Fig. 43, E and G) are also underground 
stems but they are typically vertical or erect, greatly shortened 
or flattened, solid axes that are often broader than long, bearing 
a tuft of roots at the lower surface, and a few dry, scale-like 
leaves scattered over the curved surface of the body. The 
leaves are reduced in some cases to inconspicuous dry scales. 
The nodes and buds are scarcely discernible in most corms. 
The corms are thus tremendously broadened and flattened 
leafless underground stems, of great value in propagation because 
of the accumulated food that they contain. Their r61e in 
migration is a minor one because of the slowness with which new 



70 



FLOWSM* AND FLOWERING PLANTS 



corms are formed adjacent to the old ones and because of the 
relatively slight distance -gained by each new crop. Examples 
of corms are furnished by Crocus, Gladiolus, Cyclamen, and Jack- 
in-the pulpit, Arisaema, (Fig. 43, E and G). 

Bulbs. Bulbs (Fig. 43, A, B, G and D) as a rule are also 
congested underground stems in which the stem is greatly 
reduced and the leaves take the form of thick and more or less 
succulent scales that completely cover the stem. A fringe of 
roots is developed at the base of the stem on the lower surface 
of the bulb. In contrast to a corm which is almost exclusively 




FIG. 43.- Types of congested underground stems. A, bulb of onion, Allium; 
B, vertical section of same; C and D, bulb of lily, Lilium; E, corm of cyclamen, 
Cyclamen; F, bulb of hyacinth, Hyacinthua, showing internal structure; (7, 
vertical section of the corm of crocus, Crocks (after Maihewx). 

stem with only vestigial leaves, a bulb has an inconspicuous stem 
covered by prominent leaves which constitute the dominant 
feature of bulbs as in the onion, lily, hyacinth, tulip, etc. (Pig. 43, 
A, B, C and D). The bulb usually produces a terminal bud and 
a few lateral buds in the axils of some of the scales. The new 
bulbs are usually developed from these axillary buds (Fig. 
43, B and C) and after they reach a certain stage they become 
detached from the parent bulb and in this way serve to spread 
the plants slowly from year to year. 

Runners and Stolons. A runner (Fig. 44) is a slender, trailing 
or descending, aerial stem which is practically leafless or upon 
which the leaves are conspicuously reduced. Runners arise as 
axillary growths of the parent plant and they are commonly 
very different in appearance from the ordinary stems. When 
the tip of such a stem touches the ground it may take root and 
develop a new shoot at that point. The strawberry (Fig. 44) 
and buffalo grass are plants that develop runners to a very fine 



HOW FWW BRING PLANTS TRAVEL 71 

degree and in such a manner as to assist considerably in the grad- 
ual dispersal of those plants. The thickening of the strawberry 
bed by this method of migration is a tendency very familiar 
to all strawberry growers. The competition brought about by 
this tendency must be constantly prevented if satisfactory crops 
of strawberries are to be grown. One who knows the vegetation 
of the Great Plains is aware of the same method of migration in 
connection with the behavior of buffalo grass. A study of the 
habits of buffalo grass revealed some runners that had formed as 
many as 25, 31, and 49 distinct and growing contacts with the 




FIG. 44. Runners of the strawberry, Fragana (after .\fathews). 

earth. These runners were respectively 5, 8, and 23 feet long 
and they were still connected with the parent plant. 

Stolons. The attempt is sometimes made to distinguish runners 
from " stolons," and raspberry, currant, etc. are cited as plants 
that migrate by the utilization of stolons. The only conspicuous 
differences between the stolon of the raspberry and the runner of 
a strawberry are seen in the fact that the raspberry structure is 
higher above the ground as the cane arches over to bring its 
tip down to the surface of the ground, and it has more leaves in 
evidence. 

Offsets. Another type of aerial stem of value in migration is 
the offset (Fig. 45) . This is of the nature of a very short, thick 
and comparatively leafy runner that produces a new shoot 
with a rosette of leaves when it comes into contact with the 
ground or before, and it may establish a permanent soil connec- 



72 FLOWERS AND FLOWERING 

tion by developing roots on the under surface. Such offshoots are 
usually associated with a plant of rather compact growth in 
the form of rosettes as in the houseleek (Fig. 45). This method 
of migration in such plants commonly results in the development 
of a dense bundle or mat of very closely set individuals. 




FIG. 45. Offsets developing in houseleek, Sempervivum (after Mathews). 

Velocity of Migration. The rate of migration of species by 
means of fruits and seeds is, of course, typically much more 
rapid than by anyone or another of the above vegetative methods. 
And yet these methods are effective and sure (even if slow) 
because of the extended connection with the parent plant which 
enables the potentially new individuals to maintain themselves 
until well established, even under severe conditions of stress 
that arise. A surprisingly large number of species of flowering 
plants produce rhizomes, corms, bulbs, tubers, runners, and 
offsets which have become very significantly combined with 
fruits and seeds in propagation and migration 



CHAPTER VI 
FORMS AND RELATIONSHIPS IN FLOWERS 

Comparatively little observation is sufficient to impress one 
with the fact that there are many kinds of flowers, based upon 
the number and arrangement of the common morphological ele- 
ments, i.e. sepals, petals, stamens, pistils, and axis that enter 
into the constitution of the flower. Further study demonstrates 
that these elements also vary greatly as to form, position and 
degree of union in different flowers. The outstanding anatomical 
feature of flowers, is, in short, that the floral design or plan of the 
flower shows great variety. This plan serves as the most impor- 
tant guide to the segregation of flowering plants into their major 
groups. The pattern or design of flowers as reflecting relation- 
ships is of great value in the natural classification of flowering 
plants. This is one of the most interesting phases of systematic 
botany, and one for which even the amateur or novice may 
become very enthusiastic. 

Some Common Flowers. The everyday conception of roses, 
mints, legumes, geraniums, buttercups, irises, lilies, orchids, etc. 
may not exactly convey a sense of fundamental relationships 
but it is certainly suggestive. The ability to read some of the 
secrets of floral affiliations in the flower design of unknown species 
adds a pleasure and a zest to one's travel akin to the same 
reactions that come to students of birds or butterflies. Such an 
interest will not only lead one into a finer and more intimate 
touch with the natural history of plants, but it will also help 
the intelligent to formulate a much more adequate conception 
of the nature and meaning of the natural world as a whole. 

We may now proceed to the examination of a number of repre- 
sentative flowers to illustrate some of the many variations of 
flowers that have been mentioned and that are more or less 
distinctive of the various orders and families. These features 
will enable us to build a foundation for the classification of 
flowering plants. 

Primitive Flowers and Derived Flowers. There is much 
evidence to support the conclusion that the flowering plants 

73 



74 FLOWERS AND FLOWERING PLANTS 

with their flowers developed after a spiral plan or design, i.e., 
flowers in which the carpels or stamens or both, and even the 
petals and sepals are arranged in a series of spirals (Figs. 8, A and 
B] 46, 98, 99, 102, and 103) over the axis, are more primitive than 
those with flowers with parts arranged on the whorled or cyclic 
plan, i.e., flowers in which the parts are arranged on the axis in a 
series of whorls, circles (Figs. 10, 47, 48, 49, 50, 131, 186, and 201), 
or cycles. This appears to be true even though the vast majority 
of the species of flowering plants represented in modern floras 
show flowers constructed according to the latter design. Bota- 
nists now agree almost unanimously that the flowering plants with 
spiral flowers are primitive or "low" and that those with cyclic 
flowers are derived or "high," and that the latter have developed 
from the former through long eons of time. Agreement is also 
fairly unanimous that the first or most primitive flowering 
plants were of the nature commonly known as "woody" plants. 
It is furthermore seen that the spiral type of flower is correlated 
with those groups, i.e., the lowest groups, and that the cyclic 
flower plan is adopted by the vast array of higher, herbaceous 
species. This relationship apparently goes so far in a few groups 
such as the legumes, which include both woody and herbaceous 
forms, that the herbaceous species have produced a more 
advanced type of flower than is shown by the woody species. 
This condition may be demonstrated by a comparative examina- 
tion of such representatives of the group cited (Figs. 5, D; 11, A ; 
and 146) as clover, Trifolium, or scarlet runner, Phaseolux, 
with the honey locust, Gleditsia, or thorn, Acacia. 

Some Spiral Flowers.- Many species in the families of the 
buttercup order, Ranales, may be cited to illustrate some of the 
features of spiral flowers and variations of this type. The mouse- 
tail, Myosurus, and the common buttercup, Ranunculus, produce 
floweVs (Figs. 8, A and B', 46, A and D; and 102) in which the many 
separate carpels are arranged over a more or less spire-like or 
dome-shaped axis in a series of beautifully symmetrical spirals, 
and the numerous stamens are also disposed upon the axis in a 
series of spirals immediately below the carpels. The arrange- 
ment of the carpels in these plants is emphatically reflected as 
the axis enlarges after fertilization and the individual carpels 
develop into a globular or elongated group of achenes. The 
successive spirals are also nicely shown by the scars left on the 
axis when the fruits have fallen. The carpels and stamens are 



FORM 8 AND RELATIONSHIPS IN FLOWERS 75 

attached in this manner also in the woody magnolias, Magnolia 
(Fig. 46, B, and 98), tulip tree, Liriodendron, and in many 
herbaceous members of this large group such as windflower, 
Anemone, Virgin's bower, Clematis, mousetail, Myosurus, marsh 
marigold, Caltha (Fig. 102, J5), etc. The white waterlily, 
Nymphaea alba, produces flowers in which the petals and stamens 
are also arranged spirally. 

Cyclic Flowers. The cyclic flower plan may be illustrated by a 
few of the great number of forms that are well known. Cyclic 
flowers appear to have developed from spiral flowers by a pro- 
gressive shortening or condensation of the axis, thus bringing the 
parts together in closer or more compact spirals, until the whorled 




FIG. 46. Flowers of A, mousetail, Myosurus minimus; B, tulip ires, Liriodendron, 
C, peony, Paeonia; D, buttercup, Ranunculus (after Le M. and Dec ). 

or cyclic arrangement is accomplished and a cycle is developed 
for each of the four floral elements (Figs. 47, A and B; 48, 49, 
123 and 125). The cyclic flower often shows a broadened 
receptacle upon which the succession of flower parts are disposed 
in cycles. Along with the evolution of the cyclic flower has gone 
the introduction of a much more definite number in all of the 
floral elements, in contrast with the degree of uncertainty in this 
regard that is characteristic of the l6west types of the spiral forms. 
Common Cyclic Flowers. The flowers of the strawberry, 
Fragaria, (Fig. 47, A and B) a member of the Rosales, are inter- 
esting for the reason that the many separate carpels are spirally 
arranged over a typically cone-shaped, ranalian axis, but the 
many stamens are arranged in cycles near the edge of the disk-like 
flange (Fig. 47, B) attached to and encircling the base of the 
conical portion of the axis. The five petals and five sepals are 
also arranged in successive cycles farther out on the edge of this 
disk. The flower is evidently more or less intermediate between 



76 



FLOWERS AND FLOWERING PLANTS 



the typically spiral type and the typically cyclic type, the carpels 
being spiral, and the three other elements being cyclic. In the 
flower of the mountain mahogany (Fig. 47, C) pear or apple, Pyrus, 
Malus (Fig. 145, D), the conical axis is gone, the numerous 
carpels are reduced to five, and these have become embedded in 
a depression of the fleshy axis, surrounded by the stamens, petals, 
and sepals in cyclic order. The geranium, Geranium (Fig. 48, 
#), has five sepals, five petals, ten stamens, and five carpels, 
all grouped in a very perfect cyclic manner. The flower of flax, 
Linum (Fig. 113), is composed of five sepals, five petals, five 
stamens, and five carpels arranged in the same way. The 




FIG. 47. Flowers of' A, strawberry, Frayaria; B, vertical section of a rlowei 
of Fragaria; C, vertical section of a flower of mountain mahogany, Cercocarpuj 
(after Le M. and Dec.). 

cyclic flower of a lily, Lilium, Scilla, Tulipa, Hyacinthus (Figs. 
48, A and C; 186 and 187), etc. is composed of three sepals, three 
petals six stamens, and three united carpels. 

Tubular Flowers. The arrangement of the four floral ele- 
ments is essentially cyclic also in those flowers in which the 
calyx and corolla are tubular, i.e. those in which the sepals 
are "grown together" to form a gamosepalous calyx and in 
which the petals are "grown together" to form a gamopetalous 
corolla (Figs. 50, 134, 138, 164, 174, and 175). Examples 
of these floral plans are seen in the primrose, Primula (Fig. 128), 
with its five "united" sepals, five "united" petals, five stamens 
(on the corolla tube) and its one pistil; in the sweet william, 
Phlox, with its five sepals, petals, stamens, and three united 



FORMS AND RELATIONSHIPS IN FLOWERS 77 

carpels (Fig. 137); and in the snapdragon, Antirrhinum, with 
its five sepals, five irregular petals formed into a two-lipped 
corolla, its four stamens, and its two united carpels (Fig. 151). 
The axis of the flower in these cases has been reduced to a 
slightly expanded platform at the top of the pedicel upon which 
the parts are disposed. 

Epigynous and Cyclic Flowers. Flowers with inferior ovaries 
are usually cyclic also as is seen in such forms as the carrot, 
Daucus, with its four or five sepals and petals, four or five 
stamens, and two-celled inferior ovary (Fig. 49, C), and in the 
honeysuckle, Lonicera, Diervilla, etc., with its five vestigial 
sepals, five petals "united" to form an irregular and often two- 
lipped corolla, five stamens, and its compound, inferior ovary 
(Figs. 49, A, and 174). 

Some Uncertainties. The student must not understand that it 
is readily possible to classify all flowers as either spiral or cyclic. 
These conditions merely represent a general tendency among 
flowering plants. There are many exceptions to the rule in this 
case as there are in many other principles or tendencies that are 
illustrated by living things. Thus we find that the perianth may 
be cyclic in Magnolia (Fig. 98), a member of the group in which 
spiral flowers are most clearly and typically developed. And, 
on the other hand, the floral elements are arranged more or less 
spirally in the cactus flower and in the flowers of certain other 
forms, in which other floral characteristics would indicate that 
these species are in reality of a much higher type than is accorded 
to the groups with spiral flowers. The cactuses even have the in- 
definite number of perianth parts and stamens that are commonly 
associated with more primitive groups. The cactus group repre- 
sents one of the numerous puzzles that confronts the person who 
attempts to arrange the many subdivisions of the flowering plant 
world in an orderly and systematic natural classification. The 
tendency seems to be to relate these plants to the spiral-flowered 
forms, Ranales (Fig. 102), through certain intermediary groups 
such as the roses, Rosales (Fig. 145), and myrtles, Myrtales 
(Fig. 153). 

There are many major fundamentals of floral design beside** 
the spiral and cyclic plans. Some of these have been involved 
in statements regarding different kinds of spiral and cyclic 
flowers and others have been noted briefly in an earlier chapter on 
flower structure. 



78 



FLOWERS AND FLOWERING PLANTS 



The Number of Floral Parts. The number of subdivisions or 
parts in each of the four elements of the flower presents an addi- 
tional useful aid in classification and enables us also to establish 
another "law" or principle of evolution as it is applied to 
flowering plants. The floral elements of primitive flowering 
plants are, in general, more or less numerous and indefinite 
in number. But in derived and higher flowers the tendency 
is toward reduction in number, and especially toward the 
development of a definite number of parts in each of the four 
series of elements. These tendencies are noted in the stamens 
and carpels more strikingly and in a larger number of species 
than in connection with sepals and petals. Perianth parts 
appear to become established on a definite numerical basis 




FIG. 48. Flowers of. A, squill, ticilla; B, geranium, Geranium; C, tulip, Tulipa 
(after Le M. and Dec.). 

before stamens and pistils. As development proceeds the 
number of stamens tends to become the same as the number of 
petals, but the number of carpels is frequently reduced to fewer 
than the petals. The greater reduction of carpels is probably 
more than counterbalanced, however, in many cases by the 
multiplication of ovules. In many of the highest types the 
reduction also affects the ovules, but in those (Compositae, Figs. 
176 to 180) the extreme reduction has been accompanied by 
other significant changes that have more than made up for the 
potential loss. 

Tendency toward Constancy. The tendency toward the dif- 
ferentiation of flowers with a fairly constant number of sepals 
and petals culminates rather early in the production of two 
distinctive patterns or floral designs that are correlated with 
other features to segregate flowering plants into the two major 
subdivisions, Monocotyledons and Dicotyledons. The latter 
group, commonly regarded as the more primitive, produces 
flowers that have the perianth typically composed of four or 



FORMS AND RELATIONSHIPS IN FLOWERS 79 

five each of sepals and petals? The Monocotyledons, commonly 
regarded as having been derived from the lower Dicotyledons, 
produce flowers in which the perianth is typically composed of 
three sepals and three petals. The rule is that flowers produce a 
calyx and a corolla that are distinguished from each other. 
The tendency of this distinction to be uncertain is seen mostly 
in certain types such as lilies, Lilium, Tulipa, Erythronium, 
magnolias, Magnolia, and other buttercups, Ranales, which are 
regarded as relatively primitive. 

The Union of Flower Parts. The tendency for the subdivi- 
sions of the four regular parts of the flower to become "united," 
and the degree of the union affected is another variable factor in 
connection with the development of floral designs. This tend- 




Fi. 49. Flowers of: A, honeysuckle, Lonicera; B, fuchsia, Fuchsia; C, carrot, 
Daucus (after Le M. and Dec.). 

ency affects the carpels first of all. Certain lower species, 
as of Geranium, Linum, etc. with indefinite or separate perianth 
segments have united carpels, but the many carpels in the most 
primitive groups are separate, i.e., the flowers are apocarpous. 
Separate carpels, i.e., apocarpy, is regarded as a primitive 
character, as are separate sepals, petals, and stamens. Practi- 
cally all of the flowering plants above the few groups that consti- 
tute the lower plexus of the branch have united carpels, i.e., the 
flowers are syncarpous, and the number of carpels reduced below 
that of stamens and perianth segments. 

Syncarpy: the Union of Carpels. The union between the 
carpels of compound ovaries may be slight in certain flowers as 
geranium, Geranium, hollyhock, Althaea, and flax, Linum, or it 
may be so complete as to affect even the style and stigma as in 
primroses, Primula, and mustards, Bursa. Many flowering 
plants, as legumes, Leguminosae (Fig. 146), and barberries, 



80 FLOWERS AND FLOWERING PLANTS 

Berberidaceae (Fig. 101), produce flowers with a simple pistil or 
single carpel. 

Union of Sepals and Petals. The sepals and petals of many 
flowers appear to have grown together to form a more or less 
bell-shaped, tubular, or funnel-form calyx, a gamosepaloiix 
(or synsepalous) calyx, and corolla, a gamopetalous (or sympetal- 
ous) corolla (Figs. 50, 131, 133, 134, 138, 174, and 175). This is 
the situation in practically all of the species of primroses, Primu- 
laceae (Fig. 128), heathers, Ericaceae (Fig. 131), gentians, Gen- 
tianaceae (Fig. 133), nightshades, Solanaceae (Fig. 139), mints, 
Labiatae (Fig. 144), snapdragons, Scrophulariaccae (Fig. 141), 
forget-me-nots, Boraginaceae (Fig. 140), bluebells, Campanulaceae 
(Fig. 175), and composites, Compositac (Figs. 176 to 180) 
The expressions that are commonly used to refer to these condi- 
tions are misleading, because they depict merely the superficial 
nature of the perianth whorls; whereas the actual history of 
their development is quite different. The so-called "united" 
sepals and petals are really not united to form the u synsepalous " 
calyx and the "sympetalous" corolla because they have not, as a 
matter of fact, ever been separate. We must examine the very 
young, meristematic flower in order to understand this situation. 
Such a flower will show the four floral elements merely as four 
series of zonal primordia at the end of the pedicel or axis and 
these develop later into sepals, petals, stamens, and pistils 
A flower that has five sepals and five petals at maturity will 
show five tiny humps or points of meristem that represent the 
beginnings of the sepals, and five similar points mark the begin- 
nings of the petals. If these two separate and distinct sets of 
meristematic primordia continue to grow and elongate separately, 
and if they remain separate until the flower is mature the flower 
will, of course, have five separate sepals and five separate petals. 
But in many cases such a circular zone or whorl of sepal or petal 
primordia becomes elevated on the edge of a continuous, hollow 
and more or less cylindrical band of rncristem which continues to 
grow upward in more or less telescopic fashion so that the pri- 
mordia of the sepals, or petals as the case may be, merely repre- 
sent somewhat isolated points on a cylindrical ridge of tissue 
common to all of the primordia of a given cycle. When this 
type of growth is completed in the mature flower it results 
in the formation pf the well-known tubular calyx or corolla. 
Thus we see that the four or five points on the outer rim of the 



FORMS AND RELATIONSHIPS IN FLOWERS 



81 



corolla or calyx of a gentian flower, Gentiana (Fig. 133), or the 
flower of a madder, Cinchona (Fig. 173), or coffee, Coffea (Fig. 
173), are not to be explained (as they sometimes are) by stating 
that the tendency of the sepals or petals to "unite" or "grow 
together" was terminated before the tips were reached. 

Indications of Relationships. Synsepalous and sympetalous 
flowers are commonly regarded as higher than aposepalous 
(separate sepals) and apopetalous (separate petals) flowers, 
and as having been derived from the latter types. It seems that 
"united" sepals occur in many more forms than "united" 




FIG 50 Floweis of. A, bluebell, Campanula; B, trumpctflower, Tecoma; 
(', teasel, Dipsacus, D, vertical section of a flower of cornflower, Centaurea; E, 
motmng-gloTy, Ipomoea; F, ftrvnoma; G, jessamine, Jasminum (after Lc ]\[ and 
Drr.) 

petals, but many species arc found among primitive families, 
hanunculaceac (Fig. 102), Papaveraceac (Fig. 119), Violaceac 
(Fig. 118), etc., that are aposepalous. Comparatively few Mono- 
cotyledons show synsepaly and sympetaly, but among the 
Dicotyledons we find an enormous group (Sympetalae) in which 
these conditions are very common and represented by a great 
many variations in detail. 

The degree of "union" between the sepals and petals is also 
very variable. In some flowers the sepals (as in legumes) or 
petals (as in flaxes) are united very slightly at the base, but in 
others, such as nightshades, Solanum, morning-glories Ipomoea 
(Fig. 138), Convolvulus, and blueberry, Vaccinium (Fig. 131), 
they are so completely "united" that the tips scarcely show in 
the flowers of some species. 



82 



FLOWERS AND FLOWERING PLANTS 



Union of Stamens. The stamens are also united in the flowers 
of many species in a number of different families. In the mallow 
or cotton family, Malvaceae (Fig. 105), the filaments of the many 
stamens are united to form a continuous sheath that completely 
surrounds the base of the carpels. The anthers are free and they 
usually appear as a fringing collar underneath the spreading 
stigmas that push out beyond the sheath. This feature con- 
stitutes one of the useful earmarks of that family. The numerous 
stamens in the flowers of the citrus group, Rutaceae (Fig. 114), 
especially in the oranges and their kin, Citrus, are united by their 
filaments into a number of separate groups (Fig. 114, E) but they 
do not form an unbroken sheath about the pistil. In the lobelia 
group, Lobeliaceae (Fig. 175, C), the five stamens arc united by 
their anthers, and in some cases the filaments cohere to form a 
tube. The anthers of the five epipetalous stamens are regularly 
united to form a tube in the sunflowers and their immediate kin, 
Compositae (Figs. 51, D, and 176 to 180). 

Union of Different Floral Whorls. Even members of two 
different whorls or elements of the flower arc united in some 

flower types. The com- 
monest illustration of this 
phenomenon is illustrated 
by many sympetalous spe- 
cies in which the stamens 
are raised upon the corolla 
tube and are attached by 
their filaments to the inner 
face of the petals. This is 
the condition found in 
nearly all sympetalous 
species. Such stamens are 
said to be " epipetalous." Specific cases may be cited in prim- 
roses, Primulaceae (Fig. 128), morning-glories, Convolvulaceae 
(Fig. 138), sweet williams, Polemoniaceae (Fig. 137), verbenas, 
Verbenaceae, mints, Labiatae (Fig. 144), snapdragons, Scroph- 
ulariaceae (Fig. 141), honeysuckles, Caprifoliaceae (Fig. 174), 
and coffees, Rubiaceae (Fig. 173). 

Unusual Conditions. The orchids, Orchidaceae (Fig. 203), pre- 
sent a curious case of the union of stamens and carpels, in which 
a special structure, the column, is formed by the fusion of greatly 
modified and simplified stamens and style. A more or less similar 




FIG. 51. Flowers of: A, asparagus, 
Asparagus; B, lily, Lilium; C, rose mallow, 
Hibiscus; D, Helenium (after Le M. and 
Dec.). 



FORMS AND RELATIONSHIPS IN FLOWERS 83 

arrangement is exhibited in the flower of the Dutchman's pipe, 
Aristolochia, but this case is simpler than that typical of orchids. 

Actinomorphy and Zygomorphy. Other fundamental con- 
trasts among the general schemes of floral design appear in the 
form or symmetry of the flower. Most flowers are actinomorphic 
or radially symmetrical, i.e. they are regular in form in 
all directions from the center (Figs. 8, 9 and 10). This condition 
is reflected in the more or less distinctly star-shaped or rosette 
nature that is so popularly associated with flowers. This effect 
is given by flowers in which the parts in each of the four floral 
whorls are exactly alike (or very nearly so) in form. The 
calyx, and particularly the corolla are the parts most commonly of 
major importance in this matter, but nevertheless the stamens 
and pistils also develop with perfect radial symmetry in many 
flowers. There are, however, many species of flowering plants in 
which the flowers are not so regular in form because certain 
members of one or more of the floral whorls are different in shape 
from the other members of the same series. This condition 
results in the production of lopsided flowers. These irregulari- 
ties may become surprisingly extreme and peculiar. Such flowers 
are said to show bilateral symmetry instead of radial symmetry 
and they are known among biologists as " zygomorphic " flowers 
(Fig. 11). The bizarre forms and intricate mechanisms devel- 
oped in zygomorphic flowers are among the most interesting 
features of flowering plants (Fig. 52). Such forms are found 
in many different families but they are particularly common in 
only a few such as the legumes, Leguminosae (Fig. 146), the 
mints, Labiatae (Fig. 144), the foxgloves or snapdragons, Scroph- 
ulariaceae (Fig. 141), the violets, Violaceae (Fig. 118), the com- 
posites, Compositae (Figs. 176 to 180), and the orchids, Orchi- 
daceae (Fig. 203). 

Zygomorphy in the Corolla. The corolla is the most strikingly 
modified part in zygomorphic flowers. Thus in the legumes the 
flower commonly has five petals, but these are of three quite 
different shapes and sizes and they come to occupy three different 
positions in the plane of the flower. One of the petals is usually 
much wider or larger than any of the others and this one lies in 
the upper portion of the flower as its most conspicuous part, as 
in sweet peas, Lathyrus, and has been called the banner or stand- 
ard (Fig. 52, F and G). The wings (Fig. 52, F and G) are two 
smaller and usually narrower petals which lie on either side and 



84 



FLOWERS AND FLOWERING PLANTS 



commonly, more or less, underneath the banner. The other two 
petals are usually quite narrow and smaller than the wing petals 
and are sometimes more or less united along their lower edges to 
form the keel (Fig. 52, F and G) of the flower. The petals in 
the three parts of the flower are often differently colored, and this 
serves to intensify the irregular nature of the flower. The 
stamens and pistils are closely enclosed by the keel. 

The* Mint Flower. The tubular corolla of the mint flower 
(Fig. 144), as in catnip, Nepeta, is deeply cleft longitudinally 

into two lips of dif- 
ferent shape, size, 
color, and position. 
The upper, more or 
less narrow, arching 
or erect lip is usually 
composed of two 
"united" petals, 
underneath which 
the stamens and 
style are usually 
placed, and the 
lower lip, commonly 
broad and conspic- 
uous, more or less 
lobed and differ- 
ently colored from 
the upper lip, is 
composed of three ' ' united ' ' petals. The lower li p serves as a land- 
ing platform for bees that come in search of food (Fig. 11, C). 
The Flower of the Violet. The five spreading petals of the 
violet (Fig. 118) are very diverse in form. A larger, lower petal 
usually forms a bag-like appendage or spur at its base, which 
tends to break up the symmetry of the flower. The zygomorphic 
nature of the violet is still further intensified by the irregularity 
of the stamens, two of which are inferior and have nectaries 
seated in spur-like appendages. 

Zygomorphy in Tubular Flowers. The zygomorphic features 
of the tubular flowers in the figwort or snapdragon group (Figs. 
11, 7, and 141) are extremely diversified, ranging from flowers 
that are only slightly bilobed to those that are very strikingly 
lopsided, with upper and lower lips of very different form, with 




FIG. 52.- Flowers of. A, an orchid, Phalaenopsis 
(after Kerner); B, honeysuckle, Lonicera (after Baillori); 
C, orchid, Orchis (after Lc M and Dec ); D, orchid, 
Epipactis (after Kerner); E, Tropacolum (after Le M 
and Dec ); F, pea, Pisiirn;G, same with corolla dissected 
(afttr BaiUon} 



FORMS AND RELATIONSHIPS IN FLOWERS 85 

the throat of the corolla closed by elastic lips, as in the true 
snapdragon, Antirrhinum (Fig. 141), or the lower lip developed 
in the form of a great inflated and gaudily colored sac as in the 
slipperwort, Calceolaria, etc. The stamens are also very fre- 
quently of two different types in this family. 

Zygomorphy in the Orchids. The most numerous, varied and 
interestingly complicated types of zygomorphy are doubtless 
found in the orchid family, Orchidaceae (Figs. 52, A, C and D, 
203). The orchid flower usually has three separate sepals and 
three separate petals, a tricarpellary inferior ovary, and one or 
two greatly modified stamens (Fig. 21, C, D, E and /). The 
three sepals are similar or nearly so, and are mostly different in 
color from the petals. The petals are usually in two sets. Two 
lateral petals are usually alike and constitute one of the sets. 
The third petal, called the Up, is very dissimilar and usually 
larger, often broad and spurred as in Orchis (Fig. 21, C), or 
saccate as in Cypripedium (Fig. 21, D), and Cattleya, or lobed as 
in Orchis, Diuris, or fringed as in Blephariglottis, or variously cut 
(Fig. 21, /), and commonly very differently colored. Sometimes 
the two lateral petals are also enlarged and distinctively fringed 
and marked by striking color combinations. The stamens of 
orchids are reduced to one or two, two-celled anthers with the 
pollen borne in two to eight pear-shaped, stalked, waxy or pow- 
dery masses or pollinia, which are united by elastic threads, 
and these are intimately connected to and more or less hidden 
in a specialized structure representing the style and stigma. 
There are certain orchids, Catasetum, that have developed two 
strikingly different types of zygomorphic flowers one of which 
is male and the other female. 

Zygomorphy and Relationship. The greatest expression of 
zygomorphy occurs in groups of flowering plants that are 
clearly of advanced types on the basis of other characteristics, 
and cases of the phenomenon are relatively scarce among the 
groups that are more primitive on other grounds. The principle 
or "law" here is that the earlier or more primitive flowering 
plants are those that produce radially symmetrical or actinomor- 
phic flowers, and that those with zygomorphic flowers are the 
higher and derived forms. The principle significance of zygo- 
morphy is seen in its relation to cross-fertilization through the 
agency of insect visitors, as has already been stated in the section 
dealing with pollination. 



86 FLOWERS AND FLOWERING PLANTS 

The Number and Kinds of Carpels and Ovaries. The number 
of carpels (" cells ") in the compound ovary and the position of the 
ovary in the flower are other details that are included in the 
design of flowers. It has already been pointed out that some 
flowers have many separate carpels, and that many others 
have relatively few carpels that are united to form a compound 
ovary. Ovaries of the latter type are most frequently bicarpel- 
lary (composed of two united carpels or "cells"), tricarpellary 
(three carpels), tetracarpellary (four carpels), or pentacarpellary 
(five carpels). Some flowers have ovaries that are polycarpellary . 
Each carpel in the compound ovary of lower groups commonly 
produces several ovules, so that each flower, whether with many 
or few carpels produces numerous ovules, but in higher groups the 
number of ovules per carpel tends to become reduced, and in many 
of the highest plants (as in Compositae) each flower produces but 
a single ovule in what is morphologically a bicarpellary ovary. 
Species of flowering plants in the more primitive groups tend to 
produce numerous ovules per flower, either in many, one-celled, 
separate pistils or in a single two- to-many-celled ovary, but 
species in the more advanced and derived groups tend to produce 
few ovules per flower. 

Hypogyny and Epigyny. The two commonest floral plans in 
so far as the position of the ovary is concerned are the hypogynous 
flower (Figs. 8 and 46) and the epigynous flower (Figs. 9, 49 and 
51). Hypogynous flowers are those in which the receptacle is 
more or less dome-shaped or conical, upon which the floral ele- 
ments are arranged more or less horizontally or one above the other 
with the sepals outermost or lowermost, followed in order by petals 
and stamens with the carpels or ovary innermost or topmost. In 
such flowers the pistil is said to be "superior, " and the perianth is 
said to be "inferior/' This is the more primitive plan and it 
is illustrated by the flowers of magnolia, Magnolia, buttercup, 
Ranunculus, wind flower, Anemone, Ra,x,Linum, radish, Raphanus, 
primrose, Primula, and a host of others. Epigynous flowers 
are those in which the ovary has become deeply imbedded in a 
more or less cup-shaped receptacle with which it becomes 
inseparably fused so as to constitute a unified structure. The 
other flower parts, i.e., sepals, petals, and stamens, appear to 
rise from the top of the ovary, or at least they are borne on 
a rim near the upper extremity of the fused ovary and axis. 
In this case the ovary or pistil is said to be "inferior," and 



FORMS AND RELATIONSHIPS IN FLOWERS 87 

the perianth is said to be "superior. " This is the more 
advanced flower plan and it is illustrated by many species 
in groups that are placed relatively high in our modern 
natural schemes for the classification of flowering plants, such as 
honeysuckle, Lonicefa (Figs. 49 and 52), coffee, Coffea (Fig. 173), 
madder, Rubia (Fig. 173), dandelion, Taraxacum (Fig. 178), 
thistle, CarcKlus, and the orchids, Orchis, Cypripedium, etc. 

Perigynous Flowers. A floral plan more or less intermediate 
between the hypogynous and epigynous types is represented 
by the rose or cherry (Figs. 9 and 47). The receptacle in these 
flowers is deeply concave or cup-shaped, and the pistils are 
attached more or less loosely to the bottom and in the center of 
this hollow axis, but the axis and the pistils are not grown together 
as in epigynous flowers. The sepals, petals, and stamens are 
attached in the usual order to the summit or rim of the axis, so 
that these floral elements appear to surround the pistils, instead 
of being attached below or above the pistils. This type of flower 
is commonly said to be "perigynous" (Figs. 9 and 47). It is 
evidently a transitional form between the hypogynous plan and 
the epigynous plan of floral design, a relation which is shown in 
some systems of classification. 

Incomplete and Imperfect Flowers. Incomplete and imperfect 
(monoecious or dioecious) flowers (Figs. 2, 3, 16 and 20) reflect 
in modified form many of the designs that have been treated 
in the preceding paragraphs. The plans of such flowers are 
different from the more usual types simply because the petals or 
the sepals and petals, or the stamens or the pistils may be lacking 
in the individual flower. The common interpretation has been 
that these are indicative of primitive relationships, that the 
species with such flowers have not yet developed the high degree 
of perfection that is mirrored in those species with complete and 
perfect flowers. But the alternative and more or less opposite 
conclusion has grown and spread rapidly among botanists during 
the past few years. This interpretation teaches that species 
with incomplete and imperfect (monoecious or dioecious) flowers 
are not primitive forms but in reality higher forms in which the 
flowers have become " reduced" or " simplified, " that is to say they 
have lost certain floral elements. Considerable evidence to contra- 
dict the former conclusion and to support the latter contention is 
now available. This doctrine also teaches that dioecious species 
are to be regarded as more advanced than monoecious species. 



CHAPTER VII 
FLORAL DIAGRAMS AND FORMULAE 

A very brief introduction to the problems of flower forms or 
designs that are revealed by the flowering plants of the world has 
been presented in the foregoing chapter. But these hints, few 
and briefly put though they really are, may perhaps bewilder 
the student because of a seeming multiplicity of details. The 
great wealth and variety of flower plan is indeed not lacking in 
puzzles to many who have spent years in a study of flowering 
plants. It will be profitable, therefore, to consider the nature 
and use of pictorial, empirical, and diagrammatic methods or 
other formal means of representation to portray the design of 
flowers at a glance. 

Skillfully made photographs and sketches prepared with great 
care for floral details have been very useful aids to the earnest 
student as he begins to study flowers. But the assistance that 
such materials give is rather limited and at times uncertain. 

THE METHOD OF FLORAL DIAGRAMS 

Floral diagrams that depict the nature of the flower and many 
of the details of its structure have served a very useful purpose in 
graphically portraying much that has been considered in the 
preceding chapter. The different floral elements are shown in 
such diagrams by more or less diagrammatic symbols, and these 
indicate perfectly and in proper relation many important features 
of the flower so that one with a good power of visualization has 
little difficulty in picturing the actual flower. The student will 
profit greatly by the preparation of these diagrams, especially 
during his earlier contacts with flowering plants when he has 
little knowledge of floral design. We may illustrate the method 
and the valuable possibilities of this aid by means of a few 
examples which are shown in the accompanying diagrams of the 
flowers of a number of families. 

Diagram of the Buttercup Flower. The diagram of the Ranun- 
culus flower, Ranunculaceae, shows the five separate sepals as 

88 



FLORAL DIAGRAMS AND FORMULAE 



89 



five slender crescents with their edges more or less overlapping 
on the outer rim of the figure as they would appear in a trans- 
verse section of the flower (Fig. 53, A). The five separate petals 
are indicated by a second whorl of arcs alternating with the 
symbols for the sepals. Next note the symbols of the many 
separate stamens arranged in the space between the petals and 
the carpels %t the center of the diagram. Finally, in the very 




FHJ 



.">;$ - Floral diagrams. A, buttercup, Ranunculus; /?, cactus, Opuntia; 
C, columbine, Aquilegia (after Le M. and Dec ) 



center, is shown the group of many, separate carpels that are 
characteristic of the plants in this group. Thus it is seen that 
certain features are clearly shown that are characteristic of the 
great group to which this plant belongs. An important point 
that the diagram does not bring out is the fact that the flower is 
a hypogynous flower. The spiral type is also difficult to portray 





Vm 5-1 - "loral diagrams A, poppy, Pnpnvcr, B, water plantain, Alixma; 
C, monkshood, Acomtum (after Lc ^f. and Dec.). 

by the diagram. The diagram as it stands might indicate that 
the flower of Ranunculus is perfectly cyclic throughout. 

Details shown by Diagrams. The columbine, Aquilegia, is a 
member of the Ranunculaceae also, but the flowers of this plant 
have only five separate carpels as compared to the many in 
Ranunculus, and each of the five petals is spurred (Fig. 53, C). 
These features are clearly reflected in the diagram. The numer- 
ous stamens and the normal sepals are shown about as they are in 
Ranunculus. A flower type with many stamens and many 



90 



FLOWERS AND FLOWERING PLANTS 



united carpels is shown by the poppy, Papaver rhoeas (Fig. 
54, A). The flower of aconite or monkshood, Aconitum 
(Fig. 54, C), another member of the Ranunculaceae, is strikingly 
zygomorphic. This feature is contributed by one of the five 
dark blue petals which is helmet-shaped and protects two of the 
additional petals which serve as long-stalked, tubular, two-lipped 
nectaries. The remaining petals are narrow and inconspicuous 
or they are entirely wanting. There are numerous stamens and 
three, many-ovuled carpels to complete the flower. All of these 




Fio. 55. Floral diagrams. A, mallow, ^falva; B, orange, Citrus; C, milkweed, 
Asclepias (after Le ^f. and Dec.}. 

features are shown in the diagram. The cactus flower (Fig. 53, B) 
has many separate stamens and several united carpels. 

The flower of the common Oxalis, Oxalidaceae, has five separate 
sepals, five separate petals, ten more or less united stamens, 
five of which are glandular, and five carpels grown together in a 
compound ovary (Fig. 56, A). The flower is perfectly cyclic 
and actinomorphic. All of these characteristics are readily 
shown in the diagram, but the fact that the ovary is superior 
and not inferior is not commonly shown in such diagrams. 




FIG. 66. Floral diagrams. A, sorrel, Oxalis; B, a mustard, Erysimum; C, 
sweet pea, Lathyrus (after Le M. and Dec.), 

Zygomorphy Shown by Diagrams. The type of zygomorphy 
peculiar to the beans and their kin, Leguminosae, can also be 
nicely illustrated by the diagram method (Fig. 56, C). The 
flower of sweet pea, Lathyrus odoratus, shows the typical structure 
and arrangement of flower parts with the corolla composed of 
banner, wings, and keel, the five symmetrical sepals, the ten 
stamens, nine grown together and one separate, and the simple 
pistil (Fig. 56, C). 



FLORAL DIAGRAMS AND FORMULAE 



91 



Other Floral Types Shown by Diagrams. The mustard family, 
Cruciferae, is another group in which the typical floral plan can 
be shown very well by means of a diagram. The flowers of the 
common shepherd's purse, Bursa, or wallflower, Erysimum, 
have four separate sepals, four separate petals, six stamens, 
and a bicarpellary ovary (Fig. 56, B). The flower is actino- 
morphic, cyclic, and hypogynous. All of these features except 
the position of the ovary are shown in a diagram as for rocket, 
Erysimum sp. (Fig. 56, B). 




FIG. 57. Floral diagrams. A, asparagus, Asparagus; B, spiderwort, Trades- 
cantia; C, fritillary, Fntillaria (after Le M. and Dec.). 

The Lilies. The flower structure of lilies and their kin, is 
nicely illustrated by the floral diagram method (Fig. 57). These 
flowers, as shown in Asparagus (Fig. 57, A), Tradescantia 
(Fig. 57, B), Fritillaria (Fig. 57, C), usually have three separate 
sepals, three separate petals, six stamens, and a tricarpellary 
ovary. The flower is actinomorphic and hypogynous. The 
closely related irises, Iridaceae, differ from lilies in having only 
three stamens and an inferior ovary. The difference in stamens 
is readily shown by the diagram of Iris, but the epigynous flower 




FIG. 58.- Floral diagrams. A, orchid, Orchis; B, iris, Iris; C, hly-of-the-valley, 
ConvaUaria (after Le M. and Dec.). 

is not contrasted with the hypogynous flower of the lily by means 
of the diagram (Fig. 58, B). 

The Orchids. The extreme zygomorphy and reduction of 
stamens in the orchids, Orchidaceae, may be indicated in floral 
diagrams for members of that family (Fig. 58, A). Thus in the 
showy orchid, Orchis, the greatly enlarged and inflated petal 
known as the "lip" is shown as a distortion on one side of the 
diagram, and the union of stamens and style and stigma into a 



92 



FLOWERS AND FLOWERING PLANTS 



single mass is clearly indicated, as is the tricarpellary ovary. The 
epigynous nature of the flower is not shown by the diagram 
(Fig. 58, A). 

Sympetaly Shown Also. Additional details of floral design 
such as the tubular corolla and epipetalous stamens are readily 
depicted by the diagram method. Both of these features are 
represented in hosts of Dicotyledons and they are shown in the 
floral diagram of the common potato, Solarium tuberosum (Fig. 
59, A). The flower is actinomorphic, and hypogynous and it 





Fiu. 59. -Floral diagrams. .1, potato, Solarium, B, snapdragon, Antirrhinum; 
C*j tobacco, Ntcotiana (after Le ^1 . and Dec.) 

has five separate sepals, five " united" petals to form a rotate 
corolla, five stamens attached to the shallow corolla tube on the 
lines between the petals, and a bicarpellary ovary with many 
ovules in each carpel (Fig. 59, A). The fact that the petals are 
united is shown by the connective between them, and the epi- 
petalous stamens are shown by a connection with the petals. 
A similar diagram is shown for tobacco, Nicotiana (Fig. 59, C). 




Fia. 60. Floral diagrams A, of a mint, Lamium; B, balsam, Impaticns, C, 
bladderwort, Utricularia; D, larkspur, Delphinium (after Le ^f . and Dec.}. 

The flowers of the foxglove family, Scrophulariaceae, are 
sympetalous, zygomorphic, and bicarpellary. The diagram for 
the flower of the snapdragon, Antirrhinum, reflects these features 
(Fig. 59, B). The five sepals are "united" to form a gamosep- 
alous calyx, and the five petals are "united" to form a tubular 
or gamopetalous corolla which is two-lobed. The four stamens 
are attached to the inside of the corolla tube (Fig. 59, B). Other 
zygomorphic types are shown by the mints as in Lamium 



FLORAL DIAGRAMS AND FORMULAE 



93 



(Fig. 60, A), balsam (Fig. 60, B); bladdcrwort (Fig. 60, C). 
larkspur (Fig. 60, Z)). 

Union of Stamens Indicated in the Diagram. Flowers in 
which the stamens are united by their filaments are represented 
by the mallows, Malvaceae (Fig. 85), and the citrus group, 
Rutaceae (Fig. 94). The floral diagram of a mallow, Malva 
sylvestns, illustrates the five free sepals, five free petals, and the 
ring formed by the union of the filaments of many stamens that 
completely surrounds the cluster of many united carpels at the 




FIG. 61.- Floral diagrams. A, phacelia, Phacdia, B, primrose, Primula; C, 
bluebell, Campanula (after Lc M '. and Dec.} 

center of the flower (Fig. 55, A). The .flower of the orange group, 
Citrus aurantium, has five separate sepals and petals, many 
stamens grown together by their filaments into several separate 
groups but not forming a continuous ring about the ovary with 
several united carpels (Fig. 55, B). 

Other forms of floral diagrams are shown by phacelia (Fig. 

61, A); primrose (Fig. 61, B); bluebell (Fig. 61, C); flax (Fig. 

62, A); lilac (Fig. 62, #); cucumber (Fig. 62, C and D). 




FIG. 62. Floral diagrams. A, flax, Linum, B, lilac, Synnga; C, cucumber. 
Cucumis, female; /), cucumber, Cncumi*, male (after Lc M. and Dec.) 

THE METHOD OF FLORAL FORMULAE 

The formula method of various types has also been used for 
many years to express flower structure or floral design and rela- 
tionships. The kinds of formulae developed differ considerably. 
They are designed to show graphically many features of flower 
structure and relationships and their values in classification. 



94 FLOWERS AND FLOWERING PLANTS 

Floral "Elements" and Floral "Compounds." The formulae 
presented herewith appear at first to resemble the well-known 
formulae that constitute such an important item in the equip- 
ment of chemical language. But the resemblance is naturally 
very superficial. If similar to chemical formulae at all, it is 
only in the use of symbols for the floral "elements" and in the 
attempt to reflect something of the structural relationships of 
different flowers by writing the symbols together so as to show 
the flower " compound " as a whole. A surprisingly large number 
of flowers may be treated in this manner so that different floral 
types and degrees of phyletic relationships may be shown 
graphically and at a glance by the method. 

Symbols Necessary. The number of symbols necessary for the 
successful utilization of this method are relatively few, even for 
a large number of flower types (page 159). This is a very impor- 
tant feature of the system and one which contributes greatly to its 
outstanding success. The multiplication of symbols becomes 
necessary, of course, if great numbers of plants are involved, 
but the greatest values of the method lie in the delineation and 
separation of the common orders and families in graphic contrast. 
The scheme may now be illustrated by some representative 
examples, including the forms that have already been used to 
outline the possibilities of the floral diagram method. 

Structure of the Formula. The formula of the Ranunculus 
flower shows (Fig. 63, A) the use of the method to illustrate 
the primitive type of flowering plant. The calyx (number of 
sepals) appears In the formula as Ca and the corolla (number of 
petals) as Co, stamens as S and pistils as P. The number of parts 
in each of the four floral whorls, i.e., the number of times each 
" floral element" is represented in the "floral compound" is 
indicated by an exponent. Thus in this particular plant there 
are usually five sepals and five petals so these facts are indicated 
in the formula by writing the appropriate figures as exponents, 
and the many or indefinite number of stamens and pistils are 
shown by using the infinity sign to convey the thought of an 
indefinite or irregular number of stamens and pistils. The 
whole formula may then be written as in Fig. 63, A, with all 
elements on a single plane to represent the hypogynous nature of 
the flower. The fact that the stamens and carpels are repre- 
sented as numerous and as being present in an indefinite number, 
and that they are serrate, is understood to* convey the fact that 



FLORAL DIAGRAMS AND FORMULAE 95 

the flower, in so far as the essential organs are concerned, con- 
forms to the spiral type, and the plant, therefore, belongs to a 
relatively "low" or primitive group. 

Examples of Formulae. The formula for Ranunculus may be 
very readily generalized so that it may reflect a broader series of 
floral "compounds," the family Ranunculaceae, for example. 
Such a formula would be written as is shown in Fig. 63, B. 
This portrays at a glance that the members of this family 
produce flowers that have many sepals and petals or they 
may be as few as three or none at all, with ~ 5 p 5 ro> p 

stamens typically always numerous, and pistils A A 

numerous to comparatively few, the latter H 

condition being represented by x in the 
exponent. That is, this formula means that CA C Co <P S' P x * > B 
one might expect to find flowers produced by 
some members of this family with sepals any- 
where between, say fifteen and three, petals f x P xrp> 
anywhere from an indefinite number to none c r 
whatever, but the stamens numqrous in all, 
and the carpels numerous in some flowers, but 5 s . , 
with a tendency to reduction to a smaller, more IALOJ V__ ^ 
definite number in others. The typically BAC&PSULAR 
hypogynous nature of the flower throughout for ^' lae 63 ']4~ F1 but- 
the family is reflected in the horizontal one- tercup, Ranunculus; 
storied nature of the formula. The closely ^"ttercjapjamily, 
related magnolia family, Magnoliaceae, differs magnolia family, 
from this family mainly in the woody nature ^f family, * 
of its species and in an even greater vaceae. See page 
tendency toward indefiniteness in the num- 159 for s y mbo18 - 
ber of the parts in the flower. These characteristics are 
shown in the formula (Fig. 63, C) and the uniformity of the 
exponents reflecting plasticity for all four of the floral elements. 
The formula for the Malvaceae shows certain features in common 
with the above families (Fig. 63, D). 

A weakness of all such methods as a detailed portrayal of the 
nature of plant groups should be noted at this point. Diagrams 
and formulae, when broadly generalized, are likely to convey 
misleading conceptions unless the student understands that they 
are not intended to exhibit the nature of the flowers of all of the 
genera and species that are commonly included under the various 
orders and families in standard manuals and other works on 



96 FLOWERS AND FLOWERING PLANTS 

classification. They are meant to show only the broad general 
nature of the various groups involved, and the student must 
expect to discover exceptions and inconsistencies that cannot be 
overcome by the method unless it is presented in much greater 
detail in order to treat a much larger list of forms. But such a 
plan would largely defeat the values of the scheme for all but 
the extreme specialist who really does not need the method 
anyhow. Such details must be &i necessity treated in the usual 
descriptive manner. Thus in the magnolia family, whose general 
nature has been shown in the formula, we have the tulip tree, 
Liriodendron, the flowers of which have only three sepals, but 
six petals, a degree of regularity not implied in the family 
formula. But even in this species the nature of the stamens 
and pistils clearly indicates that the plant is a comparatively 
low form, and it is inferentially close to the other group dis- 
cussed, so that the value of the formula is by no means com- 
pletely destroyed. 

Additional Possibilities. -The further possibilities of the 
formula method may be illustrated by an examination of the 

formulae of some other well-known 
groups of flowering plants. Many 
other features of the scheme, as 
well as the practical value of the 
same will be included in the sec- 

S5 r 2.5 

_, "A tions dealing with classification. 

\A UT r c IA. Loz r D j u0 t us consider next a type that 

FtScARious CAP i s markedly different from the types 

FIG. 64. Fiord formulae. A, that have been illustrated by use of 




nightshade family, Solariaccae; B, h e RanUUCUlaceae and 

phlox family, Polrmomaceae, C, ,,, , , .,,. 

leadwort family, Plumbaginaceae; aceae. 1 he phlox or SWeet William 

D, snapdragon family, Scrophuia- family, Polemoniaceae, is very 

strikingly different from the but- 

tercup family in the structure of its flowers. Many features 
of this difference may be shown in the family formula as in 
Fig. 64, B. The first thing that catches our eye in this 
formula in contrast with the floral " compound " of the buttercups 
is that the stamens have been placed afepve the line occupied by 
the three other floral elements. Next Tiote that the number of 
sepals, petals, and pistils is not nearly so varied, in fact being 
represented by a single figure and thus allowing for no common 
variation, and that the respective exponents are circled. The 



FLORAL DIAGRAMS AND FORMULAE 97 

circle about the exponent of any floral element means that 
the elements are united. In other words, it is found that the 
flowers in this family have five sepals that are " united " to form a 
campanulate or tubular calyx, that the five petals are " united" 
to produce a tubular corolla, and that the carpels are reduced to 
three, and, furthermore, that these are united to form a tricarpel- 
lary ovary or pistil. This observation now helps to visualize the 
situation with reference to the .stamens, for it is learned that 
sympetalous flowers usually have epipetalous stamens. The 
most natural manner to represent this feature of the flower is to 
write the symbol for the stamens above (upon) the symbol for the 
corolla with its united petals. The fact that the five stamens are 
attached to the corolla tube and opposite the lobes (opposite 
the petals)may be shown in the formula by a vertical bar at the 
end of the stamen line. The definite number of parts and the 
prevalence of united parts will indicate that the flower is cyclic 
instead of spiral and, consequently, representative of a high 
group. The formation of a capsule as the usual type of fruit is 
indicated by a self-explanatory symbol below the plane of the 
hypogynous flower (Fig. 64, R). 

Formulae Contrast Essential Differences. The readiness 
with which the formulae serve to contrast essential differences 
between families may again be illustratedr here. The potato 
family, Solanaceae, is commonly thought to be closely related to 
the phlox family, and these two families are usfctlly placed near 
each other in books on classification. But there must be differ- 
ences between the families or there would be no value served in 
separating them in the manuals. The essential similarities and the 
outstanding differences are reflected in the two formulae (Figs. 
64, A and B)\ The resemblances first appear at a glance. It will 
be noticed that the calyx, corolla, and stamens are shown exactly 
as in the Polemoniaceae, or phloxes. But later it is discovered that 
the pistil is bicarpellary instead of tricar pellary, and one of the 
most useful points of differentiation among the two families is 
thus found. Certainly these contrasts, as well as the similarities, 
are presented more quickly by this . means than in a lengthy 
description or even in floral diagrams.. They also portray at a 
glance the fact that these two families are representative of very 
much higher forms of flowering plants than are the buttercups 
and magnolias, according to the criteria for primitive or "low" 
groups and derived or "high" groups that have been stated. 



98 FLOWERS AND FLOWERING PLANTS 

Formulae Also Show Zygomorphic Nature. Flowering plant 
families in which zygomorphy is an outstanding feature present 
many interesting possibilities to one enthusiastic to show flower 
design by means of empirical formulae. The figwort or snap- 
dragon family, Scrophulariaceae, will furnish some excellent 
examples (Fig. 64, D). The flowers in this family are typically 
irregular or very zygomorphic. The perianth is composed of 
four or five "united" sepals, and the corolla of five petals of 
diverse form united to form a tubular, two-lipped corolla, 
with two petals in one lip and three in the other. Upon the 
limb of the corolla are borne the two, four, or five stamens. The 
ovary or pistil is composed of two united carpels. The fruit is 
usually a many-seeded capsule. The formula may be constructed 
to show all of these features, as in Fig. 64, D. The representation 
of the gamopetalous zygomorphic corolla is accomplished by 
making the symbol for the corolla Coz instead of simply Co. The 
variable number of stamens and the nature of the ovary are 
represented in the usual manner. The formula indicates with 
a brief study the similarities which exist between this family 
and the Solanaceae and Polemoniaceae and at the same time 

the basis (zygomorphy) upon which it is readily 
J>! distinguished from those families. The formula 

CA Co P A may be less generalized and more specialized in 
r4 NUTLETS ^^ such a manner as to represent the essential 
"^design of many of the genera within the family, 
> but as has been indicated that is not the pur- 

P 80 B P ose f the present work. 
l"4NuTLETs Formula for the Mints. The mint family, 

FIG. 65.- Floral Ldbiatae, also represents many interesting fea- 
",'ot ftX tures of zygomorphic flowers (Fig. 65, B). This 
Boraginaceae; B t family is similar to the snapdragons in so far as 
mmt family, Labi- Z y gornorp hy is concerned, but there are certain 

differences in the floral design of the two 
families that may be pictured graphically by means of 
the formulae. The formula for this family clearly brings out 
these features, as shown by Fig. 65, B. The calyx and corolla 
symbols are the same as in the snapdragon family, and the sta- 
mens do not show any significant points of difference. On the 
other hand, the pistil in the mints is represented as being com- 
posed, as in the snapdragons, of two united carpels, but the 
symbol clearly indicates that each of these is deeply two-lobed. 



FLORAL DIAGRAMS AND FORMULAE 99 

This condition of the pistil is furthermore reflected in the fruits, as 
indicated below the line, which are of the nature of four "bony 
nutlets. " The ovary is bicarpellary, and ea<$h carpel is deeply 
lobed or grooved. A single seed develops in each of the two 
lobes of each carpel, and the four segments separate at maturity 
as characteristic nut-like fruits that often Belie their true mor- 
phology. Thus it is readily^een that one of the greatest contrasts 
between mints and snapdragons is in the nature of their pistils. 

Further Values in Formulae. It may be instructive at this 
point to introduce another family with actinomorphic flowers 
but which has a pistil very much like the mints. This is the 
puccoon or forget-me-not family, Boraginaceae, in which the 
formula indicates striking differences as compared with mints, 
but it also shows the essentially similar ovary, as shown in Fig. 
65, A. The fact that the perianth is radially symmetrical is 
shown by the formula, and this is the most evident difference 
between the flowers of the two groups. 

A student may sometimes be puzzled by a flower from which 
the corolla has fallen, but which vStill shows the four ripening 
nutlets in the bottom of the calyx. If there are no flowers with 
corollas to be found on the specimen the question as to whether 
the plant is a mint or a puccoon may have to be settled by an 
examination of the vegetative characteristics which are fre- 
quently decisive. 

Formulae to Show Hypogyny and Epigyny. A further 
principle of floral design that may be nicely shown by means of 
formulae is the position of the ovary in the flower, i.e., whether it 
is superior (flower hypogynous) or inferior (flower epigynous). 
All of the floral patterns so far illustrated by a formula have a 
superior ovary and they may serve as examples of that type of 
formula. 

Formula for the Umbellif ers. Epigynous flowers are of various 
kinds depending upon the relation of other floral elements besides 
the pistil. Two or three types may be chosen to represent 
these. The celery or parsley group, Umbellif erae, produc 
flowers (Fig. 68, D) with a bicarpellary pistil which has become 
completely merged with the cup-shaped receptacle so as to form 
an inferior ovary with a flange or rim about the upper portion 
upon which the perianth and stamens are disposed. The five 
separate and regular sepals, the five separate and symmetrical 
petals, and the five stamens are all inserted on the edge of the 



100 



FLOWERS AND FLOWERING PLANTS 



receptacle or disk at the top of the ovary. These characteristics 
are all indicated in the family formula for this group as is shown 
at a glance in Fig. ,$8, D. This may be termed a " two-storied" 
flower in which the pistil constitutes the lower story and the 
perianth and stamens the upper story. It will be recalled that 
the flowers of phloxies, mints, snapdragons, nightshades, forget- 
me-nots are also two-storied, but ijjfcp-ll these the stamens being 
upon the corolla constitute the upper story, and the lower story 
includes the perianth and pistils, as in all hypogynous flowers. 
It is noted that the calyx and corolla are composed of separate 
parts and that the stamens are not attached to the perianth 
in any manner. As usual, certain vegetative features and fruit 
characteristics may be shown below the base line of the formula. 
The Formula for the Madders. The madders or coffee family, 
Rubiaceae, also produce flowers with an inferior ovary, but the 

two to six sepals and four or five 
petals are commonly "united" 
c to form a "limb" and tubular 
corolla respectively, and the 
stamens are "inserted" on the 





^4.3 ~ 4 5 






throat or tube of the corolla (Fig. 



-p 
P CAP 

FIG. 66. Floral formulae. A, cac- 

tuB family, Cactacear; B, honeysuckle 

family Caprtfohaceac, C, madder 
family, Rubiaceae; D, bluebell family, 



one to eight carpels, usually two, 
united to form a compound ovary. 
Thig floral degign when expljesge( j 

r i i 

ln formula manner revealwt once 

the three-Storied nature of the 
a u -111 

flower as well as a considerable 
degree of variation in the com- 

position or number of floral elements of the flowers of the 
plants usually included in this family, as in Fig. 66, C. The pat- 
tern of the flower clearly indicates that these plants are -higher 
than the umbellifers. 

Epipetalous Stamens Easily Represented. A three-storied 
flower with zygomorphic corolla is found in a number of the 
highest families. Thus in many honeysuckles, Lonicera, the 
tubular corolla is slashed into two irregular lips, a condition that 
may be shown in the formula by the device already described 
(Fig. 66, B). In the bluebell or harebell, Campanula, which 
belongs to the family, Campanulaceae, the flowers are beautifully 
actinomorphic or radially symmetrical and the ovary composed of 



FLORAL DIAGRAMS AND FORMULAE 101 

three to five carpels, as in Fig. 66, D. The stamens are more nor- 
mal in structure but are sometimes free from the corolla. 

The Cactus Type. The cactus type, Cactaceae, introduces 
another interesting floral pattern that is strikingly contrasted 
with the foregoing types by means of the formula, as in Fig. 66, A . 
There are many separate sepals and petals borne on the upper 
surface of the rim of the urn-shaped axis and an indefinite number 
of stamens also on the axis surrounding the style. The ovary 
is inferior and is one-celled, but composed of 3 to many carpels. 
This condition is represented by the usual exponent to indicate 
the number of carpels present in the pistil, in this case one, 
followed by a colon and 3 and the infinity sign, so that the 
symbols to show the structure of the pistil are written as shown 
in the formula (Fig. 66, A). 

Formulae for Monocotyledons.- All of the examples used to 
illustrate the principles and the possible values of the floral 
formula so far have beer^ selected from the Dicotyledons, but the 
same schemes are readily Adapted tp show the 
features of floral design among the Mono- G?Co s yT 6CB 
cotyledons. For examples, the arrowheads, FVMoDiAcH 
Alismaceae, is a group of Monocotyledons 
closely related to the buttercups in the ^ 3 ^ 3 <;6(3>na> 
Dicotyledon series. This relationship may be ^ p B 
shown in the forrnula along with the differ- *** 
ences that really make these plants Mono- 
cotyiectens, as in Fig. 67, A. The calyx and Qfcb'S 3 fe P ) c 
corolla are composed of three separate parts, CHAFFY FtCAP 
or sepals and petals may be lacking (in some FIO. 67. Floral 
species*); 'there are usually many stamens f <; rm uiae. A, water 

,,. i -',i - i /. . , plantain family, 

although there may be as few as six, and Aintmaceae; B, lily 
there a*;e many separate carpels. The sym- famil .v. Liiiaceae; c. 

i i r ' \ i j -i i. i A i . ,1 rush family, Junca- 

bols fw stamens and- pistils indicate that the cme . 
flowers ate spiral in so far as those organs 
are concerned.' The three-parted perianth is a monocotyledon- 
ous tendency* The hypogynous nature of the flower is repre- 
sented in the usual manner. Symbols below the base line show 
that the. members of the group are monoecious or dioecious and that 
the fruit .is usually ah achene. The usual mass of information of 
a family is here condensed into relatively small space (Fig. 67, A). 
The Lily Type in Formula. The best known type of Mono- 
cotyledon, is probably the lily or some of its close variants. The 



102 FWWERS AND FLOWERING PLANTS 

floral design of the lilies, Liliaceae, is shown by means of a 
formula (Fig. 67, #), and this may be readily varied to show the 
greater details necessary to delimit subordinate groups or even 
genera. The tripartite nature of the flowers of lilies is strikingly 
reflected in the formula. The definite number of parts, and 
especially the three pistils united to form a tricarpellary ovary 
clearly indicate a much higher type than is shown by the arrow- 
head formula. 

The Amaryllis Contrasts with the Lily. Amaryllises are also 
well known Monocotyledons, and they are not commonly dissocia- 
ted from the true lilies in the popular conception. The formula 
for an amaryllis shows that the members 

f C* C* IO DCE) 

of that group, Amaryllidaceae, are in yAlo o _ v__ ^ 
reality very different from the lilies. FVMoDi SPACER 
The group includes also such familiar 



CA 





UD.BAC- 

CA* Co 5 S 9 

p D CACoS 27 P 



MERICARP 

Fio. 68. Fio. 69. 

FIG. 68. Floral formulae . A, orchid family, Orchidaceae; B, amaryllis family, 
Amaryllidaceae; C, iris family, Indaccae; />, parsley family, Umbelh ferae. 

Fio. 69. Floral formulae. A. arum family, Araceae; B, goosefoot family, 
Chenopodiaceae; C, screw-pine family, Pandanaceae; D, cattail family, Typhaceae. 

plants as the various species of Narcissus, often called lilies but 
which differ from true lilies in having inferior ovaries (Fig. 68, B). 

The Iris Type. The flags, Iris, and blue-eyed grasses, Sisyrin- 
chium, belonging to the iris family, Iridaceae, reflect the lily and 
amaryllis pattern with still another variation. These flowers 
have three sepals, three petals, three stamens, and a tricarpellary, 
inferior ovary, the reduction of stamens to three distinguishing 
them from the amaryllids, all of which is shown in Fig. 68, C. 

The Orchid Formula. The orchids introduce numerous and 
extremely varied zygomorphic types as a culmination of the 
monocotyledonous series. More than 15,000 species are known. 
The details of orchid flowers may be found to present more 
puzzles for the formula maker to solve than any other group, 



FLORAL DIAGRAMS AND FORMULAE 103 

and yet the generalized formula (Fig. 68, A) for the family is 
not difficult to construct. The three sepals are normal or 
symmetrical, but the corolla is extremely zygomorphic on account 
of one of the three petals that is modified in a long series of odd 
forms, from broadly expanded and lobed or fringed lips to 
curious inflated bags or pitchers. The reduction in number and 
specialization of the stamens are also features of this family 
(Fig. 68, A). The intimate connection of the stamens with the 
pistil, at least with the style or stigma may be shown in the 
formula by a connective between the two symbols concerned. 
Various types of apetalous families are reflected in formula form 
in Fig. 69. Numerous additional features of floral formulae and 
their use as aids in depicting flower structure, and in the 
classification and determination of natural relationships and 
possible lines of descent in flowering plants, will be included 
under sections dealing with the various groups. The many 
possibilities in these directions are as fascinating as they are 
exhaustless. 



CHAPTER VIII 



FLOWER CLUSTERS 

It has been seen that the plan of the flowers is quite distinctive 
in flowering plants. It is also true that the arrangement of 
flowers or their aggregation into clusters upon the plant are more 
or less constant for the different species. 

Single Flowers and Clusters of Flowers. The individual 
flowers of many species of flowering plants are borne singly 
at the end of a more or less greatly elongated stalk or branch of 
the main axis of the plant. This is the case in such familiar 

plants as bluebell, Campanula, 
(Pig. 70, A), tulips, Tiftipa, mag- 
nolia, Magnolia (Fig. 98), wake 
robin, Trillium, poppies, Papaver 
(Fig. 119), Pasque flower, Pulsa- 

titta (Fig ; 70 ' B ^ ' wat(irlilv > Ndum- 
bium (Fig. 103), and windflower, 
Anemone. The stalk which bears 
the flower at the top is called the 
"peduncle." Such flowers are 
usually conspicuous because of 
their relatively large size and bril- 
liant coloration. On the other 
hand, the flowers of most species 
are gathered more or less closely 
together in simple or branched 
groups or clusters in such a manner as to increase their con- 
spicuousness, whether the individual flowers are large or small, 
brilliantly colored or less conspicuously marked. The stems or 
stalks of the individual flowers are called "pedicels," the main 
axis or stem in such cases being called the peduncle (Fig. 70, B). 
The great Swedish botanist, Linnaeus, suggested the term 
inflorescence to express the mode of flower arrangement and the 
term has been adopted throughout the world. 

Inflorescences and Relationship. Single flowers and loosely 
branched inflorescences are regarded as "low" or primitive, and 

104 




FIG. 70.- Inflorescences. A, 
single flower of bluebell, Cam- 
panula; B, single flower of Pasque 
flower, Pulsatilla. 



FLOWER CLUSTERS 105 

the more finely branched and densely compacted inflorescences 
are regarded as "high" or derived. The degree of branching 
and the density of aggregation vary within extremely wide 
limits. These relationships appear to be correlated with many 
other criteria that have been set up as evidences of the relative 
degree of specialization or advancement that different groups of 
flowering plants exhibit. 

The Kinds of Inflorescences. The two broadest types of 
inflorescences or flower clusters are determined by fundamentally 
different methods of growth in the floral branches of the stem of 
the plant. In one case the continuously growing axis of the 
inflorescence has the flowers borne as usual in the axes of the 
reduced leaves or bracts, with the oldest flowers at the base and 
the progressively younger ones toward the tip. The tip of the 
inflorescence continues its upward growth and the whole thing 
becomes more and more elongated (Fig. 71, C). As long as this 
growth continues new flower buds are opening at a short distance 
below the very tip upon which the youngest buds are often 
aggregated into a very dense cluster. It frequently happens 
that the fruits may be nearly mature at the base of such an 
inflorescence when there are many unopened and still very 
young flower buds at the tip of the same inflorescence. The 
opening of the flowers and the progressive maturation of the 
fruits and seeds in such flower clusters proceed from the base 
toward the tip, or in reality from the circumference toward the 
center when we think of the cluster in its morphological unity. 
This sequence is centripetal, and it is produced by the indefinite 
or indeterminate growth of the floral axis. This kind of inflores- 
cence is racemose, and it is by far the more common of the two 
general types among flowering plants (Fig. 71 and 72). 

THE RACEMOSE TYPE 

The Raceme. There are several different forms or varieties 
of the racemose type of inflorescence. One of the commonest 
of these is the raceme, illustrated by such plants as currant, 
Ribes aureum (Fig. 71, A), dagger weed, Yucca gloriosa (Fig. 71, 
D), Solomon's seal, Vagnera stellata, lily-of-the-v alley, Conval- 
laria, hyacinth, Hyacinthus (Fig. 186, B), agrimony, Agrimonia, 
fire weed, Chamaenerion, and pine sap, Hypopitys. The pedicels 
of the various flowers in a simple raceme are distinct and of 
about the same length at maturity so that a simple or un- 



106 



FLOWERS AND FLOWERING PLANTS 



branched raceme (Fig. 71, A) tends to become more or less 
cylindrical in form with a rather abruptly or broadly tapering 
tip as the flowers on the lower pedicels reach maturity. 

The Spike. The spike (Fig. 72, B, C and D) is a typically 
racemose inflorescence with an elongating axis that bears scat- 
tered single flowers without stalks or pedicels, i.e., the flowers are 
sessile. Plants that produce this type of inflorescence are 
mullein, Verbascum, plantain, Plantago (Figs. 72, B and 129, A), 
pondweed, Potamogeton, orchids, OrcMs rotundifolia, glasswort, 
Salicornia, and prairie clover, Kuhnistera. The various flowers 
usually fall away from the axis of the spike separately or indi- 




FIG. 71. Inflorescences. /I, raceme of currant, Ribes; B, axillary flowers of 
partridge berry, Mitchdla, O, panicle of bluebell, Campanula; D, compound 
panicle of yucca, Yucca fjlomoxa 

vidually . The axis may be persistent after all, or nearly all, of the 
flowers have fallen. Certain other peculiar spike-like flower 
aggregates may be included here as variations of the typical 
spike. 

The Catkin. A catkin (Fig. 72, A) is of the nature of a spike, 
but it commonly produces only staminate or pistillate flowers, and 
at maturity the whole structure falls away as a unit, as in the 
staminate inflorescence of birch, Betula (Fig. 72, A), walnut, 
JuglanSy hickory, Hicoriaj hazel, Corylus, chestnut, Castanea, 
oak, Quercusy and in both the staminate and pistillate inflores- 
cences of willow, Salix (Fig. 127, A, B, D and E), and cotton- 
wood, Populus (Fig. 127, C). The distinction between a catkin 
and a spike is sometimes difficult to make, but the endeavor is 
probably of value. The catkin-like spikes of pistillate flowers in 
the mulberry, Moras , become the ripe "fruits" or mulberries in 
the popular sense. 



FLOWER CLUSTERS 



107 



The Spadix. The spadix in the calla lily, Calla, Richardia, 
Jack-in-the-pulpit, Arisaema (Fig. 190, B\ skunk cabbage, 
Spathyema, calamus, Acorus, the arrowarum, Peltandra, dasheen, 
Colocasia, and other members of the arum family, Araceae, is a 
more or less elongated, congested, and thickened, fleshy axis 
bearing the sessile, commonly fleshy flowers which are perfect, 
pistillate, or staminate. The spadix is commonly surrounded 
and partly enclosed by the spathe (Fig. 190) which is often 
believed to be a flower because of its brilliant coloration. In the 
Jack-in-the-pulpit the spadix is "Jack" and the spathe is the 
"pulpit" within which he stands. 

The " spike" or "head" in many wild grasses and cereals such 
as in timothy, Phleum (Fig. 198, A), Hordeum, and in cultivated 
rye, Secale, wheat, Triticum, 
and barley, Hordeum, is in 
reality a compound, spike- 
like inflorescence. There is a 
sessile cluster of flowers (a 
spikelet or group of spikelets) 
at each node in this floral 
axis instead of a single flower 
as in the typical spike. 

The Corymb. The corymb 
is a racemose inflorescence in 
which the pedicels of the 
lower or older flowers are 
much longer than those of 
the upper or younger flowers. 
This condition tends to bring 
all of the flowers of the entire cluster to lie in a single plane, 
and so the inflorescence is more or less convex or flat topped. 
Examples of this type of inflorescence are afforded by candytuft, 
IberiSj and certain cherries, Prunus cerasus. 

The Umbel. The umbel is an inflorescence in which the axis is 
very short and more or less knob-like, upon the top of which the 
numerous pedicels appear to arise (Fig. 73, A and B) from 
about the same point, and, spreading radially, raise their 
flowers to form a convex or flat-topped cluster. The pedicels 
are sometimes called the rays of the umbel. The floral bracts at 
the bases of the pedicels are brought close together at the axis of 
the umbel. In many cases this cluster of bracts is rather 




FIG. 72. Inflorescences. A, male cat- 
kin of birch, Betula; B, spike of plantain, 
Plantago; C, spiko of vervain, Verbena! 
D, bracted spike of lobelia, Lobelia. 



108 



FLOWERS AND FLOWERING PLANTS 



conspicuous and they form the involucre. This type of flower 
cluster is very common in the group of plants known as the 
"umbellifers," Umbelliferae (Fig. 172), to which belong the 
carrot, Daucus, dill, Anethum,, celery, Apium, parsnip, Pastinacq', 
myrrh, Myrrhis, and caraway, Car am, as well as in the onion, 




Via. 73. Inflorescences. A, compound umbel of Lomatium; JB, simple umbel 
of cherry, Prunus. 

Allium, milkweed, Asclepias (Fig. 136), and ginseng, Panax. 
The order of blooming in the corymb and the umbel is centripetal 
or from the outer '(lower) edge toward the center (upper), as in a 
typical raceme. The flowers on the border of the umbel 
may open very much earlier than those in the center of the 




Fio. 74. Inflorescences. A, head of buttonbush, Cephalanthus: B, head of 
rosin weed, Grindelia. 

inflorescence. After the fruits have started to form on the 
pedicels in the umbels of certain species (carrot) the clusters 
become tightly infolded to form a rather compact ball with most 
of the fruits in the center of the tangled mass of pedicels. 

The Head. A head is an inflorescence of the racemose type in 
which the numerous flowers are sessile; i.e., it is much like an 



FLOWER CLUSTERS 



109 



umbel in which the flowers lack pedicels or is of the nature of a 
shortened, globular spike (Fig. 74). This type of flower cluster 
is also often globular or almost spherical as in the buttonball tree 
or sycamore, Platanus, buttonbush, Cephalanthus (Fig. 74, A), 
alsike clover, Trifolium hybridum, and in the pistillate inflorescence 
of osage orange, Toxylon. The head is the characteristic inflores- 
cence in the composites, Compositae (Fig. 74, B), or the group to 
which sunflower, Helianthus, dandelion, Taraxacum, lettuce, 
Lactuca, goldenrod, Solidago, etc., belong. The flower in a pop- 
ular sense in this family is in reality an inflorescence which con- 
tains many or even hundreds of separate true flowers. 

THE CYMOSE TYPE 

The second general type of flower cluster or the cymose inflores- 
cence (Fig. 75) differs markedly from the racemose type because 
the upward growth of the floral axis is early brought to a close by a 




PIG. 75. Iriftorebeences .1, simple cyme; B ami C, other forms of the cyme. 

terminal flower. The first or oldest flower to open is at the tip 
and the later or younger flowers appear progressively lower down 
on the axis; in other words, the tendency for the floral axis to 
elongate is definitely terminated by the presence of the flower at 
the tip. The growth of the floral axis in this case is determinate. 
The opening of the flower buds proceeds from tip to base or from 
center to circumference in such flower clusters, which are there- 
fore of the centrifugal type (Fig. 75). The cyme is thus seen to be 
the exact opposite of the raceme in the position of the youngest 
and oldest flowers and in the sequence of blooming. Cymose 
flower clusters are not nearly so common as the racemose type. 

The Solitary Flower. The simplest type of cymose or determin- 
ate inflorescence is seen in those plants in which a 'solitary, 



110 FLOWERS AND FLOWERING PLANTS 

terminal flower is produced on the peduncle, as in the poppy, 
tulip, etc. But in those plants which produce a cluster of flowers 
on the peduncle the simplest unbranched forms are represented by 
the crab apple, Pyrus. 

The Fascicle. A fascicle is a cyme with the flowers very closely 
crowded as in campion, Lychnis, and sweet william, Phlox. 

The Glomerule. A glomerule is a cyme which is still more 
condensed or compacted, much like a head. This inflorescence 
may usually be distinguished from a head by the order of opening 
of the flower buds, i.e., they open from the center to the circum- 
ference as in all types of determinate inflorescence. Certain 
species of dogwood, Cornus, box, Buxus, and nettle, Urtica, 
illustrate this type of flower cluster. 

COMPOUND INFLORESCENCES 

There are also many kinds of branched or "compound" flower 
clusters among both indeterminate and determinate inflorescences, 
and still others in which there are two types represented in the 
same inflorescence. Here is another instance of the practical 
inability of man to classify natural phenomena to his satisfaction. 

The Panicle, Corymb, Etc. One of the commonest forms of com- 
pound or branched racemose inflorescences is the panicle (Fig. 
71, C), so abundantly represented in the grasses (Figs. 197 and 
199) such as bromes, Bromus, oats, Avena (Fig. 197, A), bluegrass, 
Poa, panic grass, Panicum, as well as in Virginia creeper, Partheno- 
cissus, and many others. The simplest type of panicle is like 
that of the Virginia creeper in which the group of flowers is much 
like an ordinary raceme, but with a simple raceme produced where 
there would be a single flower in the ordinary raceme. This 
type of branching is seen in its extreme form in the "compound 
panicle" in which the branching runs into several branch orders. 
The compact inflorescence of certain other grasses such as wheat, 
Triticum, and Italian rye, Lolium, is also compound in the sense 
that the main axis, the rachis, is branched to form the rachilla of 
the spikelets, upon which the sessile flowers are borne. Certain 
species of hydrangea, H. cinerea, produce compound corymbs. 
Compound cymes are seen in the common elder, Sambucus, 
mountain ash, Sorbus, black haw, Viburnum, and in many 
hydrangeas. Many of the umbellifers, Umbelliferae (Fig. 172), 
produce 'compound umbels, in which there are two (possibly 



FLOWER CLUSTERS 111 

more) series of branches formed. The secondary umbels are 
then called "umbellets, " and the secondary clusters of bracts 
about the bases of the secondary pedicels in the umbellets are 
termed "involucels. " 

Mixed Clusters. Inflorescences in which some of the above 
types are mixed are shown by the horse-chestnut, Aesculus 
hippocastanum, lilac, Syringa, and privet, Ligustrum, in which 
the primary branching order is of the indeterminate order, but 
the secondary or ultimate branching order is partly or wholly 
determinate. Such an inflorescence may be elongated or con- 
tracted and it is called a "thyrsus." The elongated, loose, panicle- 
like inflorescence of this type is seen in meadow rue, Thalictrum, 
and the contracted, pyramidal form is seen in lilac, horse-chestnut, 
and privet. 

OBLIQUE INFLORESCENCES 

Spikes, racemes, and cymes are produced in certain families, 
Boraginaceae, Hydrophyllaceae, which become strikingly lopsided 
because the flowers fail to develop on one side of the axis. 
This condition is cdmmonly intensified by the continued elonga- 
tion of the floral axis by the development of lateral branches 
formed in the axils of leaves on one side of the stem only. Such 
clusters are known as "scorpoid" spikes, racemes, or cymes. 

STERILE FLOWERS, BRACTS, ETC. 

Sterility of Certain Flowers in the Inflorescence. The flowers 
in some of the higher types of inflorescence are functionally 
differentiated into those that are inconspicuous but which 
perform the normal function of reproduction, and those that are 
very conspicuous and as such serve to attract pollinators. The 
conspicuous flowers in many such species have become sterile so 
that they serve only for attracting the insects to the inflorescence. 
These conditions are seen in a great variety of forms in the 
composites, Compositae (Figs. 176 to 180), where in many species 
of the sunflower type the outer row of flowers in the head become 
brilliantly colored and they form a gay band or ring of radiating 
flowers, hence ray flowers. These surround a dense cluster of less 
showy, but nevertheless very important flowers that occupy the 
central part of the head, the disk, and are therefore called disk 
flowers. The prominent ray flowers contribute an essential 



112 FLOWERS AND FLOWERING PLANTS 

showiness to the inflorescence, but they often suffer the loss of 
their stamens, and frequently their pistils also. The sacrifice 
certainly rebounds to the great advantage of the species so 
constituted because a single visit from a bumblebee, coming as 
to a single flower, may supply sufficient pollen to fertilize the eggs 
in scores or even hundreds of flowers. The possession of this 
nature as a regular feature of the life history is largely responsible 
for the common opinion that the composites are the highest of all 
flowering plants. 

Floral Bracts, Involucres, Etc. The same sort of attractive- 
ness in the inflorescence of many other species is secured through 
the coloration and placement of a perianth-like cluster of vegeta- 
tive bracts. Thus in the callas, Calla, Jack-in-the-pulpit, 
Arisaema, and many of their kin, Araceae (Fig. 190), the colored 
spathe that surrounds the spadix (the real inflorescence) serves 
the function of attractiveness much as would be supplied by a 
gaily colored corolla. The flowers themselves are very small, 
inconspicuous, and often are not seen from the outside because of 
the sheathing spathe. But the spathe, although not a part of the 
flower, is the banner that lures the pollinators and so makes 
fqrtilizaUftm possible. , The beautiful, white, petal-like bracts 
that surround Ufre inconspicuous clusters of flowers in the flower- 
ing dogwood of the south, Cornus florida (Fig. 171, A), and of the 
northwest, Cornus nuttallii, serve the same purpose. The three 
beautiful magenta or purple bracts enveloping the true flowers of 
Japanese paper plant, Bougainvillea, are of the same nature and 
perform the same function. A similar situation is illustrated by 
the brilliant scarlet or purple bracts that constitute the attractive 
whorl or rosette surrounding the cluster of unattractive flowers 
at the top of the stem in the magnificent Central American 
Poinsettia, Euphorbia pulcherrima, so popular at Christmas time, 
and the white or white-margined bracts in a similar position 
about the flowers of the common snow-oh-the-mountain, Euphor- 
bia marginata (Fig. 116, E\ of the prairies and plains of North 
America. 

The Biological Meaning of Flower Clusters. There is doubt- 
less considerable biological significance attached to the different 
kinds of flower clusters. It is impossible for us as yet to interpret 
the meaning of many of the finer details associated with the 
higher types of inflorescences, as is true for many of the other 
structural features of plants, but, nevertheless, we are able to 



FLOWER CLUSTERS 113 

see important values associated with the broader aspects of 
flower groupings. For instance, many of the advantages of the 
prominent conspicuousness of large, brilliantly colored, single 
flowers are doubtless secured in those species with many very 
much smaller flowers by arranging them in more or less closely 
aggregated clusters. In this way the inflorescence composed 
even of very tiny flowers, each with most attractive color com- 
binations but which would be scarcely seen alone, becomes a very 
conspicuous affair. The cluster resembles a single large flower. 
This, naturally, is greatly to be desired for the showiness of a 
migle large flower here becomes the property of a cluster of 
flowers for the attraction of pollinating insects. Insects visit 
and pollinate the cluster of flowers as readily as they visit and 
pollinate the single flower. This condition may normally result 
in the production of a comparatively greater crop of offspring, 
much to the advantage of the species with the multiple-flowered 
inflorescence. 



CHAPTER IX 

VEGETATIVE CHARACTERISTICS OF FLOWERING 
PLANTS 

Considerable emphasis has been given to the fact that the 
flower is really the most distinctive feature of the flowering plants. 
The various groups that the biologist recognizes in the classifica- 
tion of those plants are largely and more or less easily differen- 
tiated because of the great variety of detail exhibited by flowers. 
A given natural group of flowering plants owes its principal 
biological distinction to the presence of a certain type or kind of 
flower. This type of flower is different from the flowers that 
characterize other groups. Thus we find that the most reliable, 
practical, and scientific basis for the recognition of the various 
natural groups of flowering plants is revealed by the nature of the 
flowers that they produce. Much attention must be given, there- 
fore, to the careful study of the comparative morphology of 
flowers as the primary and most dependable basis of classification. 

The flowers of a given group of flowering plants show much less 
tendency to vary widely than do the other structures of the 
plants, and it is for this reason that the characteristics of flowers 
are the most dependable features for use in any scheme of classi- 
fication. Nevertheless, the vegetative or somatic structures of 
flowering plants are also of great value in a simple classification 
or in extensive scientific taxonomy. These characteristics 
include all the organs of the plant other than those immediately 
involved in the structure of the flower. They include the great 
variety of form and structure of roots, stems, and leaves that 
are associated with flowering plants. Such characters are 
extremely varied and numerous, since they often reflect the 
influence of more or less local or transient conditions of the 
environment, as well as being present to a characteristic degree 
for the various species under all conditions. 

In spite of their greater variability the vegetative organs of 
flowering plants are exceedingly useful, along with flowers, in 
working out the usual diagnostic characteristics of different 
plants. The vegetative characteristics that are so useful in 



VEGETATIVE CHARACTERISTICS 



115 



classification are reflected by a technical terminology that is quite 
distinct from that used in the description of flowers. To give the 
principal vegetative structures of flowering plants, together with 
some of their more or less common variations, and a sampling 
of the vocabulary utilized in their description is the object of this 
chapter. Further details in the matter of the special terminology 
and use of the terms involved in systematic description are to be 
mastered only by extended use of the standard manuals and 
floras in the laboratory and field. 

ROOTS 

The roots of a plant normally grow downward into the soil and 
more or less firmly anchor the plant in place. Roots are, there- 
fore, typically subterranean. There are numer- 
ous species of flowering plants, however, that 
produce roots that are wholly or in part aerial 
(Fig. 78). The roots of certain orchids are truly 
aerial, many of* them never reaching the ground, 
and the so-called "prop roots" of maize and 
screw pine are also partly aerial. On the other 
hand the main stems of certain species arc subter- 
ranean, and so there is considerable popular 
confusion because of the common assumption 
that all underground parts are roots. The dis- 
tinction between roots and stems must include 
other features (external and internal anatomy, 
development) besides their position. 

Roots differ from stems in their development 
and internal anatomy, in the absence of more or 
less regular nodes and internodes, and in the 
absence of leaves. The roots of certain plants, 
under certain conditions, develop adventitious 
buds from which leafy shoots or "root sprouts" 
arise, as in the poplar, apple, and black locust. 
Roots are often formed on the leaves of certain 
plants, also, and they are produced in abundance 
on the aerial stems of various species (Fig. 78). 
Roots usually branch very irregularly, although the form of the 
root (Fig. 76) and the root system (Fig. 77) are quite charac- 
teristic of different species and under different conditions of the 
environment. 




FIG. 76. The 
fleshy root of a 
carrot; an en- 
larged taproot of 
a biennial (from 
Pool, Basic 
Course in Bot- 
any, Ginn and 
Company) . 



116 



FLOWERS AND FLOWERING PLANTS 



Kinds of Roots. Roots that are fine, thread-like, and often 
provided with long, slender, and numerous branches of about the 
same diameter are called fibrous roots. Such roots are revealed 
especially by the grasses (Fig. 77) and sedges. The outer 
branches of the root systems of trees and shrubs, the fine branches 
of many fleshy roots (Fig. 76), and the roots that arise from 
underground stems arc also fibrous. 




FIG. 77. The fibrous root systems of blue grama grass, left, and wire grass, 
right (from Weaver and Clements, Plant Ecology, Fig. 159, page 316, McGraw-Hill 
Book Company, Inc.). / 

Roots that are notably enlarged by the formation of tissues 
that are stored with water and food are termed fleshy roots. 
Good examples of fleshy roots are seen in the carrot (Fig. 76), 
turnip, radish, and beet. 

The main root and its numerous branches in most trees and 
shrubs become greatly thickened and dominated by hardened, 
woody tissues and so may be called woody roots. The woody 
root is usually covered with much the same cortical tissues and 
bark that are characteristic of the stems of such plants. The 



VEGETATIVE CHARACTERISTICS 117 

woody roots of the Dicotyledons grow in diameter by the forma- 
tion of annual rings as do the stems of such plants. The pro- 
gressive development and increasing woodiness of the root system 
of such plants keep pace, more or less, with the development and 
age of the aerial portions of the plant. 

The more or less spreading cluster of large fleshy or tuberous 
roots of the dahlia are called fascicled roots. Other descriptive 
terms for roots are used in books on classification, such as fusi- 
form, for fleshy roots like those of the dahlia and sweet potato, 
and napiform, for those of the turnip and certain beets. 

Root Systems. The fully developed root or root system, as to 
origin and duration, is either primary or secondary (or adventi- 
tious). The primary root and root system arise from the hypo- 
cotyl of the embryo. The primary root is the first root that 
appears as the seed germinates, and it usually grows directly 
downward. The main axis of the root system developed from 
this is the primary root; if it persists, it is called the tap root, as 
in the carrot, sweet clover, and dandelion. The branches of the 
primary root or tap root arc often fibrous and are called secondary 
roots. The primary root is very short-lived in many plants, and 
it is succeeded by a secondary root system which arises from the 
epicotylary region of the seedling or from almost any vegetative 
shoot. The secondary roots and root system of this type become 
the permanent roots that are so characteristic of the grasses 
(Fig. 77) and many other Monocotyledons. The roots that arise 
on such modified,- underground stems as bulbs (Fig. 43), corms 
(Fig. 43), tubers, rhizomes (Fig. 68), on such aerial stems as 
stolons, runners, and on cuttings or slips and leaves are also 
secondary roots. Secondary roots are often called adventitious 
roots, irrespective as to where or how they are formed. 

Duration of the Root. The length of life of the normal indi- 
vidual plant depends upon the duration and effectiveness of its 
root system. In relation to this fact the taxonomist recognizes 
three types of flowering plants, namely, annuals, biennials, 
perennials. Annual species are those in which the individuals 
live but one year (or growing season). Biennials live for two 
years, perennials for more than two years. 

Annuals arise from seeds, produce their regular vegetative 
characteristics, flower, fruit, and die in a single year. Such 
plants are generally herbaceous or even fleshy. But the indi- 
viduals of certain annual species under certain environmental 



118 FLOWERS AND FLOWERING PLANTS 

conditions may become very large and develop much woody 
tissue; in fact, they may tend to become biennial or even peren- 
nial. Certain plants are known as winter annuals. These are 
normally annuals in which the seeds if planted in the autumn will 
germinate and a certain aerial growth will be produced in the fall 
and will live through the winter. Growth is greatly retarded 
during the winter but it is resumed again the following spring, 
with the production of flowers and a new crop of seed, after 
which the plants die as in winter wheat. A notable feature of 
the life history of winter annuals is the development of a rather 
extensive root system in the autumn. The aerial development 




FIG. 78. Aerial roots of poison, ivy, at r; fruits at / (from Pool, Basic Course in 
Botany, Ginn and Company}. 

at that time is commonly in the form of a dense cluster of leaves 
on a short shoot (a rosette). 

Biennials require two full years (growing seasons) for the com- 
pletion of their individual life cycle from seed to seed. The seeds 
germinate the first year, and the young plants develop a good 
root system and an aerial rosette of leaves or a well-developed 
leafy shoot. The root and shoot are usually supplied with a rich 
store of food by the end of the first vegetative year, but no flowers 
are produced. During the second year the individual plants 
form their flowers and seeds and, with the exhaustion of their 
root systems, die. The stems of biennial species are also usually 
herbaceous, but various species may produce large individuals 
with an abundance of woody tissues. 



VEGETATIVE CHARACTERISTICS 119 

Perennials are plants that live and continue to grow for two or 
more year^. Numerous perennials produce herbaceous aerial 
shoots that die at the close of the first year and each succeeding 
year, but the root system (and underground stem system) may 
persist for many years and continue to produce the usual aerial, 
annual shoots, as in many grasses, sedges, rhubarb, and aspara- 
gus. Numerous other perennial species produce aerial shoots 
from perennial root systems that are also perennial and that 
continue to live and grow (more or less) from year to year, as do 
the roots, as in our common trees and shrubs. 

STEMS 

The stem or shoot of the plant, with its few or many branches, 
usually grows upward into the light. It is an effective system 
whose primary value to the plant as a whole is to display the 
leaves in such a manner as to favor their food-making activities. 
Exceptions to the generally erect or ascending habit of stems are 
seen in numerous species that produce stems so short and incon- 
spicuous that such plants are said to be acaulescent or stemless. 
The slender stems of certain species crawl along the surface of 
the ground or climb upward by means of the coiling habit or 
by the use of tendrils or aerial roots that anchor the weak stems 
to the support. Still other species produce some or all of their 
stems underground. The habit and structure of stems are so 
variable among different species that such vegetative features 
are of great value in classification. These characteristics are 
reflected by an extensive and more or loss technical vocabulary, a 
representative sampling of which we may introduce at this 
point. 

Typical Stems. All stems have nodes (joints) and internodcs 
(intervals between the nodes), in contrast with roots, and the 
leafy shoots and their branches originate in buds at the nodes or 
at the tip of the shoot and its branches (Figs. 79, 80). 

Buds are embryonic or immature shoots in a dormant state and 
are commonly covered, especially in the winter buds of trees and 
shrubs, by bud scales, which in themselves are modified leaves. 
A terminal bud may occur at or near the tip of the shoot and its 
branches, and from such buds the longitudinal growth of the 
shoots is produced. The lower buds are called lateral buds, and 
these are axillary buds (Figs. 80, 84) if they arise in the axils of 



120 FLOWERS AND FLOWEBJI$& PLANTS 

the leaves (as they usually do). When more than one lateral bud 
occurs in an axil, either at the right and left of the central bud or 
above the latter, such extra buds are called supernumerary buds, 
as in the honeylocust. Buds that have no bud scales are called 
naked buds, as in Geranium and Kalmia. Injuries to the inter- 
nodes may result in the formation of 
adventitious buds almost anywhere between 
the nodes; such buds often form on the 
leaves of Bryophyllum. 

If a bud gives rise to a leafy shoot, it is 
termed a leaf bud; if to a flowor or inflores- 
cence, it is called a flower bud. When a bud 
gives rise to a leafy shoot and flowers, it is 
called a mixed bud. Transitions from bud 
scales to typical leaves are shown in 
Pittosporum. 

When the scales of a bud fall, they leave 
more or less distinctive bud-scale scars (Fig. 
80) that mark the former position of the 
bud scales at the nodes. A series of such 
bud-scale scars left by terminal buds some- 
times marks several years' growth in elon- 
gation of the branches. But such scars 
become obscure or even eliminated com- 
pletely as woody stems become older and 
thicker. Buds vary greatly in arrangement, 
numbers, size, shape, color, and nature of 
the surface and in the number, arrangement, 
color, size, shape, and surface nature of the 
bud scales. The characteristics of buds are 
of especial value in distinguishing different 
species of trees and shrubs in winter. 

Kinds of Stems. As to age, stems are 
annual, biennial, or perennial, much as has 
been noted for roots, since the length of life 
of the root determines the duration of the 
It has been pointed out that many perennials produce 
shoots that live for a single year, even though the root system 
is truly perennial, whereas, in many species, the shoot system is 
also perennial and the latter may become massively or exten- 
sively developed. Many perennials form highly modified under- 




Fro. 79. Tip of 
butternut twig show- 
ing terminal hud at T, 
leaf scar at L, acces- 
sory bud at Ace, 
axillary bud at Ax, 
bundle scars at Vas 
(from Pool, Basic 
Course in Botany, 
Ginn and Company). 

stem. 



VEGETATIVE CHARACTERISTICS 



121 



ground stems from which arise the "new plants" or aerial shoots 
each year. 

As to position, stems are aerial or subterranean (submersed). 
The aerial shoot system is more or less erect in most species, but 
in many species the stem is more or less 
prostrate, decumbent, creeping, crawling, 
or climbing. Climbing stems are usually 
slender and weak, and they are able to 
cling to a support by means of the twining 
habit or by the formation of tendrils or 
aerial roots. Numerous terms are em- 
ployed to describe these features. Cer- 
tain species with aerial steins often form 
special branches that are helpful as 
propagativc structures. Among such 
modified aerial shoots may be mentioned 
stolons, runners, and offsets (see Chapter 
VIII). Stolons are slender branches of 
the shoot that creep over the surface or 
near the surface of the ground, often 
rooting and forming new shoots at the 
nodes. Runners are much like stolons 
(Fig. 44), but they form a single node 
between rather long internodes. The 
bud at the tip of the outer node of a 
runner often takes root and so may 
develop a new plant in that position 
which may eventually separate from the 
parent shoot system by the breaking of 
the long iiiternode. Offsets are relative- 
ly short and often more or less fleshy 
stolon-like branches of a short stem (Fig. 
45) forming a cluster of leaves at the 
tip. Such modified branches as offsets are usually associated 
with plants of rather compact growth in the form of rosettes, as 
in the houseleek (Fig. 45) . The primary value of all of these and 
similar types of aerial stems is in relation to natural vegetative 
propagation. Man utilizes such natural tendencies to propagate 
certain economic species for his own advantage. 

Special reference should be made to tendrils, thorns, and 
cladophylls as modifications of the aerial stem (Fig. 82). Tendrils 




FIG. 80. Tip of a twig 
from the horse-chestnut 
showing a terminal dor- 
mant bud, numerous leaf 
scars with their bundle 
scars, and transverse 
bands of bud-scale scars 
marking terminal growth 
for 10 years (from Pool, 
Basic Course in Botany, 
Ginn and Company). 



122 



FLOWERS AND FLOWERING PLANTS 



are usually slender, leafless branches of the shoot that are very 
sensitive to contact stimuli; they are thus especially useful in 
attaching the stem to a support, and in that way they enable the 
weak short plant to climb into an advantageous position for the 
display of its leaves to light. The tip of the tendril may be 
simple or branched into fine hair-like segments, or it may be 
expanded in the form of an adhesive disk, as in the Boston ivy. 
It should be noted in passing that the 
tendrils of certain plants (Fig. 146A) are 
modifications of leaves or leaflets. 

Branches are sometimes modified to 
form thorns. These are simple or un- 
branohod, as in the osage orange, or they 
are branched as in the honeylocust. The 
stems of desert shrubs and trees often 
grow slowly, and many of their branches 
become dwarfed and more or less thorn- 
like. 

CladophylLs (phylloclades) are more or 
less flattened, leaf-like stems, that may 
quite readily be mistaken for true leaves, 
the functions of which they do perform. 
Certain species of asparagus, A. aspara- 
goides, and the Scotch broom, Ruscus 
aculeatus, produce typical cladophylls. 
The cactuses with strongly flattened, 
green internodes, and those with more or less cylindrical, 
columnar, and ribbed green stems, in which the nodes arid 
internodes may or may not be prominent, may also be mentioned 
among the peculiar or special types of aerial shoots. 

The subterranean shoot system is usually so highly modified and 
specialized for vegetative propagation as to be confused with the 
root system. So effective are the various types of subterranean 
stems in multiplication that many economic species are regularly 
propagated in this mariner by growers. The essential features 
of the more common modifications of this sort are presented in 
Chapter V, with special emphasis upon migration and ecesis. 
All these structures (Figs. 40 to 45), with their various inter- 
gradations and other details, are utilized to a considerable degree 
by taxonomists in drawing the descriptions for use in classifica- 
tion. The behavior of the subterranean stem system and of 




FIG. 81. Twining 
stern of the hop % plant 
(from Pool, Basic Course 
in Botany, Ginn and 
Company). 



VEGETATIVE CHARACTERISTICS 



123 



certain of the highly specialized aerial shoots as well has received 
special and prominent consideration and application in connec- 
tion with the recent emphasis upon the value of vegetation in the 
practical problems of soil conservation. 

Special Features of Stems. Reference has already been made 
to the presence of bud-scale scars on the surface of shoots, 
especially of the branches of woody stems. We may also refer 




FIG. 82! Tendrils of the bur cucumber. Various stages in the development 
of tendrils are shown at a, b, c, d, e, and / (from Pool, Basic Course in Botany, 
Ginn and Company} . 

here to the leaf scars that are left on the surface of the shoot 
when the leaves fall. The latter are so distinctive of different 
species (Figs. 79, 80) and are so readily described as to be of 
considerable value for purposes of identification. It should be 
remembered that a new leaf is never formed in the exact position 
of a former leaf. 

Lenticels. The surface of the internodes of many woody shoots 
also reveals the presence of prominent lenticels. These are 
raised, sunken, or otherwise circumscribed spots of such distinc- 



124 FLOWERS AND FLOWERING PLANTS 

tive color, form, and size in the outer bark that they are readily 
differentiated from the adjacent surface of the bark (Fig. 83). 
They commonly appear as rounded, oval, or horizontally elon- 
gated spots or streaks that are characteristic of various species 
and ages of twigs. They are composed of tissues that aid in the 
aeration of the underlying and deeper portions of the twigs. 
Lenticels are especially prominent in the birch, elder, and 
cotton wood. 

Bark. One of the commonest features that we associate with 
woody plants, especially trees, is bark. According to the com- 
mon usage of the term, this includes all the tissues outside the 
cambium cylinder in woody plants, and as such it consists of 




FIG. 83. Lenticels in the bark of wild black cherry (from Pool, Basic Course in 
Botany, Ginn and Company) 

various tissues, including cork, in extremely varied combinations. 
The bark of many species is quite distinctive ; hence, it is of value 
in classification. Large trees and even saw logs are readily 
identified by the experienced woodsman and forester by the 
bark alone. In spite of the extreme value of bark from the stand- 
point of taxonomy, we find that satisfactory and dependable 
terms have not yet been put into use for its reliable description. 
Such expressions as " smooth bark/ 7 " rough bark/' " scaly 
bark," "shag bark" are so general as to be of little value for 
accurate taxonomic work. The situation is also complicated by 
the fact that the bark on the older branches and the main trunk 
of old trees is very different from that on the younger branches of 
the current twigs and young trees. The bark of young twigs 



VEGETATIVE CHARACTERISTICS 125 

often shows certain details that are helpful for diagnostic purposes 
but that are entirely lacking on the older twigs of the same indi- 
vidual tree or shrub. The variations in the bark that character- 
ize the shoot from youth to old age must be available if bark is to 
to be of major value to the taxonomist. 

Other Surface Features of Stems. The surface of herbaceous 
species and the young shoots of woody plants is often more or 
less covered with hairs or scales of various types or coated with 
granular, sticky, or resinous substances that are helpful for 
descriptive purposes. These characteristics are likely to vary 
with the age of the shoots, too, and even to show puzzling differ- 
ences as among different portions of the same individual or 
different individuals of apparently the same species under differ- 
ent environmental conditions. 

Various technical terms are in common taxonomic use to 
include these features in the preparation of the diagnoses one 
finds in the various floras and manuals. Since the same, or 
nearly the same, features are also found in the surface markings 
of leaves, where they arc more often utilized in detail, they will be 
presented in our treatment of the vegetative characteristics of 
leaves to follow immediately. 

LEAVES 

The green color of vegetation is usually due to the presence of 
an abundance of green leaves which are in turn colored by the 
presence of the well-known but complex pigment chlorophyll. 
The most significant primary function common to all green leaves 
is manufacture of carbohydrate foods. Leaves are the most 
variable, anatomically, of all of the regular parts of the plant, 
notwithstanding their uniform primary functions. There are 
several well-known species of flowering plants (the orchid, 
Corallorrhiza) that are not even green and that, because of the 
absence of chlorophyll, are saprophytes. The gross and the 
minute morphology of mature leaves varies widely among differ- 
ent species, among different individuals of the same species, and 
even among different parts of the same individual. Many 
flowering plants may, nevertheless, be readily recognized by their 
leaves alone. The value of leaves (as well as of other vegetative 
structures) in taxonomic work is distinctly limited unless exten- 
sive observations and comparisons are made under various con- 



126 



FLOWERS AND FLOWERING PLANTS 



editions. Even then due consideration must be given to the 
extreme variability of leaves. 

Typical Leaves. Leaves are typically characterized by their 
green, expanded, very thin blade or lamina, which is attached to 

the aerial stem at a node by the 
leaf stalk or petiole (Fig. 84). 
We must point out, however, 
that all true leaves are not green, 
nor are they all broad and thin, 
nor are they confined to aerial 
shoots. The petiole is often 
lacking, and then the leaf is said 
to be sessile (Fig. 87, C). The 
petiole itself is extremely Vari- 
able as to length, thickness, and 
form of base and cross-section. 
And then stipules are present in 
many species. Stipules are 
lateral, more or less leaf-like, 
outgrowths (usually two) at the 
base of the petiole (Fig. 84). 
They are sometimes large and 
distinctly leaf -like, permanent, 
and so characteristic as to be 
very useful for purposes of classi- 
fication, as in the willow, poplar, 
and rose. Stipules are absent in 
many species (as mustards), 
whereas in others they have 
fallen by the time the leaf is mature. They develop as a "leaf 
sheath" (ocrea) that more or less completely surrounds the stem 
in the buckwheat and smart weed. In certain plants (Qalium) 
the stipules are so much like the blades of the sessile leaves as 
to be indistinguishable from them. 

Arrangement of Leaves. The leaves of flowering plants are 
arranged on the stem in a definite and regular manner. In many 
species they are opposite; i.e., there is a leaf on opposite sides of 
each node. In other species the leaves are whorled or verlicillate; 
i.e., there are more than two (three or more) at each node. 
In many species only one leaf occurs at a node; the leaves are 
then arranged in a definite spiral order at the successive nodes 




FIG. 8 4. Representative leaf. 
A, blade; B, petiole; C, stipules; 
D, axillary bud. 



VEGETATIVE CHARACTERISTICS 127 

and are said to be alternate. When the two leaves occur on 
opposite sides of each node, each pair is usually placed at right 
angles to the pair immediately above or below, thus forming four 
vertical rows of leaves. Certain plants, notably the grasses 
(including maize), in which the leaves are alternate form two 
vertical rows (ranks) of leaves, whereas in other alternate-leaved 
species there are three-to-many rows. In some species both 
opposite and alternate leaves occur upon the same individual. 
Vernation. Young leaves are usually folded or rolled in the 
bud in a definite manner. The manner of folding or rolling, 
which may be determined from transverse sections of the buds, is 
termed vernation. When not folded or rolled at all, they are said 
to be straight. 




FIG. 85. Types of vcination. A, inflexod or lechnate; B, conduphcate, C, 
convolute; D, riroinate. 

The principal types of vernation are: inflexed or reclinate 
(Fig. 85, A), in which the blade or upper part of the leaf is bent 
back over the lower part; conduplicate (Fig. 85, #), in which the 
blade is folded lengthwise along the midrib (as leaves in a book) 
the two halves being thus brought face to face, usually with the 
lower faces outermost, as in oak and cherry; convolute (Fig. 85, 
C), in which the blade is rolled lengthwise, from side to side, like 
a scroll, as in rose and plum; circinate (Fig. 85, D), in which the 
blade is rolled from the tip toward the base, with lower surface 
outermost, as in sundew (and ferns) ; involute (Fig. 86, ^4.), in which 
both edges of the blade are inrolled lengthwise over the upper sur- 
face toward the midrib, as in violet; revolute (Fig. 86, J3,) in which 
both edges of the blade are inrolled lengthwise over the lower 
surface toward the midrib, as in dock; plicate (pleated), in which 
the blade is creased and folded back and forth (accordion-like) 
along the main veins like a pan (Fig. 86, C), as in the palmately 
veined leaves of mallows and geraniums. 



128 



FLOWERS AND FLOWERING PLANTS 



Venation. The visible veins (vascular bundles) of the blade 
are so distributed as to be helpful for diagnostic purposes. 
These common vegetative characteristics are referred to by the 
term venation. In respect to venation, leaves are pinnately 
veined (feather-veined) when the prominent subdivisions of about 
equal size diverge from the prominent midrib toward the margin 
of the blade and are approximately parallel (Figs. 87, B; 91, A). 
When the more prominent veins radiate from a common point 
at or near the base of the blade, the venation is said to be palmate 
or digitate (Fig. 87, A). In parallel venation the principal veins 
(of about equal size) extend from the base to the tip of the blade 
and are more or less parallel, and the branches of these veins are 




FIQ. 86. Types of vernation. A, involute; B, revolute; C, plicate. 



inconspicuous (Fig. 87, C). When the veins appear as a more or 
less irregular network of gradually diminishing size, the term net 
venation is used. 

Simple and Compound Leaves. With reference to the con- 
figuration of the blade, leaves are either simple (Figs. 84, 87, 90) 
or compound (Fig. 88, A and B). The blade may be regular in 
outline with no marginal indentations whatsoever, or it may be 
indented, lobed, or deeply cut on the margin; but as long as it is 
in a single unit or piece, it is simple. The leaves of many plants 
are completely divided and the two or more pieces separated into 
individual parts called leaflets (Fig. 88, A and B) ; such leaves are 
then designated compound leaves. 

The leaflets of compound leaves show all the common charac- 
teristics of simple leaves except that all the leaflets of a given 
compound leaf lie in a single plane, do not have stipules, and do 



VEGETATIVE CHARACTERISTICS 



129 



not bear buds in their axils. The continuation of the axis (peti- 
ole) of a compound leaf is called the rachis. There are two kinds 




FKJ 87. Types of venation. A, palmate; B, pinnate; C, parallel. All these 
leaves are simple. A is petiolate; C is sessile. 

of compound leaves, palmate ly compound, in which the leaflets 
diverge from a common point at the tip of the petiole, as in the 




FIG. 88. Compound leaves. A, pinnate; B, digitate or palmate. 

horse-chestnut (Fig. 88, J5), and pinnately compound, in which 
the leaflets are distributed along two sides of the common rachis 
(Fig. 88, A). The rachis of such a leaf is, in fact, homologous 



130 



FLOWERS AND FLOWERING PLANTS 



wih the midrib of a simple pinnately veined leaf. The leaf- 
lets of a pinnately compound leaf may themselves be compound 
one or two times, as in the honeylocust and certain acacias. Such 
leaves are said to be twice or doubly compound, or bipinnate, or 
twice pinnate, or thrice pinnate. 

The Outline of the Leaf. The outline of simple leaves and of 
the leaflets of compound leaves is among the most variable of all 
leaf characteristics. Because of such extreme variation, these 
features are often puzzling, and the terms for them in our tax- 




FIG. 89. Outlines of leaves. A, lineai ; B, lanceolate; C\ oblong; D, elliptical, 
E, ovate; F, deltoid; G, orbicular (peltate); H, spatulate; /, cuneate; J. seculate. 

onomic descriptions are often difficult to use concretely and con- 
sistently. They are, nevertheless, among the commonest terms 
of systematic botany. 

The General Outline. The outline of the leaf or leaflet is 
described as linear when it is very narrow and usually much 
longer than broad, with more or less nearly straight sides and 
ending in a blunt or tapering apex (Fig. 89, ^1); lanceolate, 
when lance-shaped, broadest below the middle, and usually 
tapering gradually to a pointed apex (Fig. 89, J5); oblong, when 
rectangular, with nearly straight sides and with rounded base 
and tip (Fig. 89, C); elliptical, like an ellipse, broadest at the 
middle, tapering broadly and evenly to the rounded base and 



VEGETATIVE CHARACTERISTICS 



131 



tip (Fig. 89, D); ovate, when egg-shaped, much broader below 
the middle, with base rounded and apex blunt or rounded 
(Fig. 89, E); orbicular, more or less nearly circular (Fig. 89, 
G); deltoid, like a delta or triangular (Fig. 89, F)', seculate, 
sickle-shaped, more or less like a curved and oblique lance- 
olate leaf (Fig. 89, J) ; spatulate, spoon-shaped, broad and rounded 
above the middle, tapering gradually to a narrow base (Fig. 
89, H) ; palmate, like the leaf of a fan palm ; cuneate, wedge-shaped, 
usually narrow but broader above the middle, then tapering 
toward the base, with sides usually straight (Fig. 89, /). Oblance- 
olate and obovate leaves are inversely lanceolate and ovate, 
respectively. 




FIG. 90. Bases arid outlines of leaves. A, cordate; B, remfoim; C, saggitate; 

/>, hastate. 

The Base of the Leaf. With particular reference to the base of 
the blade, simple leaves may be: cordate, heart-shaped, rounded 
and indented at the base (with a sinus) and tapering broadly to 
the apex (Fig. 90, A); reniform, kidney-shaped, broader than 
long, with a sinus at the base (Fig. 90, B)', saggitate, arrow- 
shaped, with a deep sinus at the base and the projecting 
sides of the base of the blade (auricles) turned inward (Fig. 
90, C); hastate, halberd- or spear-shaped, with auricles turned 
outward (Fig. 90, D); peltate, shield-shaped, with the petiole 
inserted at or near the center of the blade (Fig. 89, G); 
auriculate, with auricles or "cars" formed by the projection 
of the two sides of the base of the blade, as in saggitate 
and hastate leaves; oblique, with the two sides of the blade 
unequal, especially at the base (Fig. 91, A); decurrent, in which 
the blade appears to "run down" the sides of the stem (Fig. 
92, A); connate, in which the bases of two opposite leaves appear 
to have fused about the stem (Fig. 91, #); perfoliate, in which 



132 



FLOWERS AND FLOWERING PLANTS 



the stem appears to pass through the base of the blade (Fig. 
91, C); sheathing, in which the expanded base of the petiole more 4 




FIG. 91. Bases of leaves. A, oblique; B, connate, C, perfohato, D, clasping. 

or less completely invests the stem (Fig. 92, B) ; clasping, in which 
the blade of the sessile leaf partly invests the stem (Fig. 91, D). 




FIG. 92. -Bases of leaves A, deem rent, B, sheathing 



The Tip of the Leaf. With reference to the apex or tip of the 
blade, leaves are acuminate when narrowly tapering to a sharp 
point (Fig. 93, A)] acute, when tapering more broadly to a sharp 
point (Fig. 93, B); obtuse, when tapering abruptly to a point 
(Fig. 93, C) ; aristate, when ending in a bristle or awn (Fig. 93, E); 



VEGETATIVE CHARACTERISTICS 



133 



cuspidate, when ending with a sharp, rigid point (Fig. 93, D); 
truncate, when the tip seemingly is cut off square or nearly so 
(Fig. 93, F)', retuse, when the tip is rounded or slightly notched 
(Fig. 93, G); emarginate, when decidedly notched (Fig. 93, H). 
The Edges of the Leaf. The edges or margins of the blade of 
leaves and leaflets exhibit a wide variety of modifications in the 
nature of indentations. Terms in use to describe the common 
types of these include, for the shallower indentations, the follow- 
ing: entire, said of leaves the margins of which are smooth, i.e., 
not cut or toothed in any manner (Fig. 94, A ) ; repand or undu- 
late, having the margin wavy (Fig. 94, B) ; sinuate, with deeper, 
wavy indentations (Fig. 94, C) ; serrate, with marginal teeth like 




FIG. 93. Tips of leaves. A, acuminate; B, acute, C, obtuse; D, cuspidate; E, 
anstate; F, truncate; G, rotuse; H, omargmate. 

a saw, especially with teeth pointing forward (Fig. 94, E)', ser- 
rulate, with very small or fine teeth (Fig. 94, D) ; dentate, having 
the margin cut with teeth (fine or coarse) that point straight out- 
ward (Fig. 94, F)', crenate, scalloped, or having broad rounded 
teeth (Fig. 94, G). Terms used for more deeply cut edges are: 
incised, having the margin deeply cut into irregular or jagged 
teeth (Fig. 95, A)] lobed, cut more deeply into curved or angular 
lobes (Fig. 95, B) or cleft, cut, or lobed so that the sinuses 
extend about halfway to the midrib ; parted, cut so that the sinuses 
between the lobes extend nearly to the midrib (Fig. 95, C); 
divided, cut entirely to the midrib, as in compound leaves 
(Figs. 88; 95, D). When the leaf is of the pinnate form of 
venation, the forms of lobing or dividing are described as pin- 
nately lobed, cleft, incised, parted, divided (Fig. 88, ^1). When 
the venation is palmate, the terms are, of course, palmately 
lobed, cleft, incised, parted (Fig. 95, C), divided. The number 
of lobes or divisions of such leaves vary and are indicated by such 
terms as pinnately or palmately three-lobed, -cleft, -incised, 
-parted, or -divided. When the divisions are numerous and more 



134 FLOWERS AND FLOWERING PLANTS 

or less fine and narrow, we use such expressions as dissected, 
multifidj or pinnatifid, or pinnately dissected. 

Variations in the Surface of Leaves. The upper and lower 
surfaces of the leaves of numerous species are smooth and slightly 
modified; but, in many others, the lower, the upper, or both sur- 
faces are marked by the presence of hairs, scales, or resinous or 
waxy coatings of various kinds. Some of the more common 
details of such modifications are revealed by the following selected 
terms which one often sees in taxonomic descriptions. 




FIG. 94. Edges of leaves. A, entire; B, repand (undulate); (7, sinuate; D, 
serrulate; E, serrate; F, dentate; G, crenate. 

The glabrous leaf is devoid of pubescence or hairs; the gldbrate 
leaf is almost lacking in hairy covering, or the leaf becomes 
glabrous at maturity. Various types or degrees of hairiness arc 
implied in such technical terms as canescent, coated with fine 
white or hoary hairs; hirsute, with stiff hairs; hispid, with bristly 
hairs; pilose, with soft, slender hairs; puberulent, with very fine, 
down-like hairs; scabrous, rough to the touch; sericeous, with 
silky pubescence; strigose, with rigid hairs or bristles; villous, 
with long, shaggy hairs; floccose, with tufts of soft, silky hairs. 
Of a different (not hairy) sort of epidermal modification we find 
the squarrose (squarrate) type, with minute scales, and the ver- 
rucose, with minute warts or blunt projections; glutinous, sticky 
or mucilaginous; glandular, with glands in the surface or gland- 



VEGETATIVE CHARACTERISTICS 



135 



tipped hairs; glandular-punctate, dotted with resinous glands; 
glaucous, covered with a whitish, bluish, or greenish waxy mate- 
rial or "bloom"; pulverulent, covered with a finely powdery sub- 
stance; pruinose, covered with a coarse granular material. There 




Fia. 95. Edges of leaves. A, incised; J5, sinuately lobed or incised; C, palmately 
parted; D, pinnately divided. 



are various additional terms that one notes in the descriptions of 
leaves (many of which also apply to stems) in taxonomic works. 
Special Kinds of Leaves. Certain species of flowering plants 
produce vegetative structures that are properly known as leaves, 
but these may be so modified as to appear quite different from 
typical leaves. Among these structures may be mentioned the 



136 FLOWERS AND FLOWERING PLANTS 

bracts and bracteoles or greatly reduced leaves that often accom- 
pany the individual flowers in an inflorescence; scales or storage 
leaves and the dry scales of bulbs, corms, tubers, and rhizomes 
(Figs. 40 to 45) and the regular components of scaly buds; certain 
tendrils (as in sweet pea) that are highly modified and sensitive 
leaflets; stipules, which are often leaf-like; the spines of certain 
cactuses and other desert plantvS are modified leaves, petioles, or 
the rachis of a leaf. Of unique interest are the modified leaves 
of the so-called "insectivorous" plants as those of the sundew, 
Drosera, and Venus' flytrap, Dionaea, and the pitcher-like 
leaves of the "pitcher plants" as in Sarracenia and Nepenthes. 
These leaves are equipped with special mechanisms to entrap 
and digest the bodies of various insects and other small animals. 
They are of great popular and scientific interest. 



CHAPTER X 
THE CLASSIFICATION OF PLANTS 

The primary object of this book is to assist students in their 
endeavor to master the knowledge requisite for the proper 
understanding and interpretation of flowers and for the classifica- 
tion of flowering plants. Classification, in general, is a conven- 
ience and a necessity of all phases of modern life. The necessity 
and the great convenience of classification must be apparent in 
the daily life of each of us. We are all enabled to do much more, 
to accomplish more because the facts, the customs, and the 
work of past ages and of our time have become fairly well clas- 
sified and systematized. So human life, in its complexity and 
variety of interests, profits greatly from the age-old endeavor to 
classify. 

Science attempts to systematize knowledge. It is therefore 
readily understood that classification is one of the first require- 
ments of systematized knowledge. Civilization has progressed, 
in fact very largely, with the slow growth of the ability of people 
'to classify and to systematize the materials, the thoughts, and 
the ideals with which the human race is associated. 

TAXONOMY 

Principles of Classification. The endeavor to arrange plants 
into groups and subdivisions is commonly spoken of as " classifica- 
tion." Certain practices, rules, or principles of classification 
have gradually developed during the centuries, and, today, we 
have the subdivision of biology known as " taxonomy" which 
deals primarily with the principles of classification. The word, 
taxonomy, comes from two Greek words meaning " arrangement" 
(or classification) and "law." So taxonomy treats of the laws 
governing the arrangement or classification of plants. Tax- 
onomy naturally contributes greatly to the orderly study of 
plants and to the systematization of our knowledge of plants, so 
that phase of botany in which taxonomy is the principal interest 
is called " systematic" botany. 

137 



138 FLOWERS AND FLOWERING PLANTS 

The Basis of Classification for Plants. We may base our 
classification of flowering plants upon a great variety of character- 
istics possessed by the members of this largest and most varied 
group of the vegetable kingdom. We may use such features as 
environmental conditions, methods of obtaining food, anatomy, 
life history, size of body, color of flowers, uses in daily life, 
geographic distribution, etc., as the bases of classification. Thus 
we may distinguish such groups as land plants and water plants; 
shade plants and sun plants; parasitic plants and saprophytic 
plants; simple plants and complex plants, alpine plants and 
lacustrine plants, etc. And, of course, we should understand 
that various less comprehensive subdivisions may be made of the 
primary groups or subdivisions. All of the above and many 
other types of classification may be found in the books dealing 
with the varied interests that man takes in plants. 

The difficulties involved in a classification which shall include 
all flowering plants known may be appreciated when we under- 
stand that this branch of the vegetable kingdom contains at 
least 150,000 different kinds of plants that are now known to 
botanists. A recent estimate by a British botanist places the 
number at 230,000 species. But this condition should not be 
staggering because some other groups of natural objects contain 
many more types or different kinds than that. 

Evolution of Plants. Botanists now understand that the 
plants of the vegetable kingdom in all parts of the world are 
related through time as well as sjDace. In other words, when 
traced back far enough, all plants are found to have had common 
ancestors. This means that we regard the plant world as a 
vast assemblage of organisms in many diverse groups, but all 
linked more or less closely together by similarity of structure 
and development. Such similarity may be close or distant, or, in 
other words, the relationship may be near or remote. Some 
plants may be close to certain ancestral types, but others may be 
quite distantly related to those same ancestors. This is what we 
mean by relationship among plants. It is a conception somewhat 
similar to relationship among groups of animals and amorig the 
families of human beings. It is in reality a sort of "blood" 
relationship, but we must not understand that plants possess a 
body fluid like the blood of higher animals. We might perhaps 
question the conclusion that relationships among the higher 
animals are determined largely by the blood which flows through 



THE CLASSIFICATION OF PLANTS 139 

their bodies. That fluid is of chief importance from the stand- 
point of nutrition, rather than of primary significance in heredity, 
which is of great value in really determining relationship. 
Indeed, inheritance is well known among plants and among many 
animals in which there is no blood. 

Natural and Artificial Systems. So in botany as in zoology we 
commonly endeavor to group or to classify organisms in accord- 
ance with what is understood about their original relationship. 
Relationship, " blood relationship," is the basis for our commonly 
used classifications of the organisms constituting the vegetable 
kingdom. This is known as " phylogcnetic " or natural classifica- 
tion, in contrast with "artificial" classification which may be 
based upon any other characteristics of the plants, even to the 
point of ignoring the fact of descent. In using this conception as 
a basis for the systematic classification of flowering plants we 
should keep in mind the fact that close similarity usually indi- 
cates relatively close relationships while dissimilarity indicates 
relatively distant relationships. 

The Names of Plants. As we look about us we readily notice 
that plants exist as many different and variable kinds. It has 
become the practice among botanists to designate the different 
kinds of plants as " species/' and to give each species a particular 
name. We easily recognize several different kinds or species of 
oaks, maples, grasses, ferns, seaweeds, toadstools, etc., and we 
find that botanists have given names to these in order that they 
may refer to them intelligently. The naming of plants and the 
principles involved in giving names to plants are included in that 
phase of systematic botany known as "nomenclature." 

The Number of Plants. The study of the plant life of the 
world has revealed the fact that the vegetation of the earth is 
composed of a great many different kinds or species. Botanists 
have described probably more than 250,000 different species of 
plants, some of which are found in great numbers in many places 
and over a very wide territory, while others are sparingly repre- 
sented and restricted to a relatively small area. Doubtless there 
are others that have not yet been discovered. The most notice- 
able differences in the vegetation of diverse regions of the world 
are due to the fact that different species of plants are represented 
there or have become dominant in the different places. 

Necessity of Classification. It is quite impossible for any one 
person to know all of the 250,000 species of plants that have been 



140 FLOWERS AND FLOWERING PLANTS 

described from all parts of the earth. If it were not for the fact 
that plants exhibit the principle of relationship as conceived by 
botanists, and that they may be classified into various groups on 
this basis, the vegetable kingdom would, indeed, appear as a cha- 
otic assemblage of very diverse types. Few people appreciate the 
fact that the plant world is not such a heterogeneous association 
of unlike forms. The main purpose of this section of our study 
is to learn that flowering plants may be very readily regarded in a 
much more systematic light, simply by mastering a few of the 
principles of plant classification which are now well known to 
botanists. The main subdivisions or groups, and the terms 
selected for these that are now in common use in such a classifica- 
tion will next be examined. 

THE COMMON GROUPS 

The Species Concept. The 150,000 or more different kinds 
or species of flowering plants are each represented by many 
individuals, no two of which are exactly alike, but they vary 
within narrow limits. A species is regarded as a group containing 
all of the individuals of a particular kind of plant that exist now 
or that existed in the past, no matter where they were or where 
they may now be found. The great French botanist, de Jussieu, 
long ago defined a species as : the perennial succession of similar 
individuals perpetuated by generation. The conception of "similar 
individuals" is difficult to define, and it varies greatly with 
different workers, but it is ordinarily based upon a study of the 
significant and common characters shown by large numbers of 
the individuals. Mere differences in size, shape, color of body, 
etc., may not mean different species. Naturally some species are 
represented by very many individuals, as, for example, the west- 
ern yellow pine, Pinus ponderosa, but in other cases there may be 
comparatively few individuals in a species as it is known today, 
as in the Monterey cypress, Cupressus macrocarpa. The number 
of individuals now or in the past is not necessarily an important 
consideration in the conception of a species or of any other group 
in our classification. 

The specific name is an adjective, a noun in apposition, a noun 
in the genitive case, or a common noun in the genitive plural. If 
the specific name is an adjective, it must agree with the generic 
name in gender. Such a name is often selected to indicate some 
outstanding or distinguishing characteristic of the species, as 



THE CLASSIFICATION OF PLANTS 141 

rubra, "red," or sericeus, " silky." In actual practice, specific 
names sometimes suggest a locality, a habitat, or even a person, 
as canadensis, "in Canada," aquatica, "in water," smithii, "after 
Smith." Adjectives used as specific names are sometimes formed 
by adding the Greek termination, -oides, -oideus, -ides, or -odes, 
which means "resembling" or "like," to some common noun or 
generic name. Examples of the use of these kinds of specific 
names are, Populus deltoides, the "poplar with leaves that are 
delta-like or delta-shaped," and Elymus triticoides, " the Elymus, 
or wild rye, that resembles Triticum" 

If the specific name is a noun in apposition, it is in the same 
case, nominative singular, as the noun with which it is in apposi- 
tion, but it does not necessarily agree with it (the genus) in 
gender. Examples of this type of binomials are: Allium cepa, 
tho onion, Prunus cerasus, the sour cherry, and Nicotiana tabacum, 
the early name for tobacco. 

When the specific name is a noun in the genitive, as it is when 
it is formed from the name of a person, it is usually formed by 
adding i or ii to the name of the person connected with the plant, 
as Prunus besseyi, Bessey's cherry, or Plantago purshii, Pursh's 
plantain. 

Examples of specific names that are genitive plurals are 
Colocasia antiquorum, the colocasia of the ancients, and Con- 
volvulus sepium, the bindweed of the hedges. 

It would seem that it is preferable, in the preparation of 
specific names, to avoid the formulation of specific names that do 
not tend (at least) to portray some feature of the plants named. 
There are too many meaningless names of plants that are merely 
the Latinized forms of person's names, given as a supposed honor. 
There is a strong growing tendency to decapitalize all specific 
names, even those derived from the names of persons and geo- 
graphical areas. 

The Genus Concept. Individual plants within certain close 
limits of variation are all grouped together to constitute a species. 
Likewise, different species may also be grouped together to form 
a series or group of higher rank and with wider limits of variation 
in our scheme of classification. These next higher groups are 
called "genera" (singular, "genus"). A genus is a group or a 
series of species just as a species is a collection of individuals but 
the differences between the units (species) are greater than 
within a species or between the units (individuals) of a species. 



142 FLOWERS AND FLOWERING PLANTS 

The genus includes those broader characteristics that are common 
to all of the species. Thus, all of the species (or kinds) of oaks 
belong to a single genus, Quercus, all of the species of maples to a 
single genus, Acer, all of the species of elms to a single genus, 
Ulmus, as illustrative of the practice of grouping species into 
genera. 

The generic name is a noun in the singular and is always 
written with a capital when used technically, or the word may be 
decapitalized when used as a common name, as Crocus, crocus, 
Rhododendron, rhododendron. The capital letter is an essential 
feature of the name when used in the generic sense. Many 
generic names have been chosen to indicate some character- 
istic feature or features of the species included in the genus, 
as Mirabilis, the four-o'clock, from the Latin mirabilis, " wonder- 
ful/' and Spiranthes, the ladies' tresses, from the Greek speira, 
"spiral," and anthos, " flower," from the arrangement of the 
flowers in the cluster. Numerous generic names are also given 
to honor persons, as Claytonia, the spring beauty, after Clayton, 
an early American botanist, and Linnaea, the twin-flower, after 
Linnaeus, the great Swedish botanist. 

Generic names are derived from almost any language; but in 
form either they are the original Greek or Latin names, such as 
Carum, the caraway, or Rosa, the rose, or if from some other 
language, they must be Latinized. When Latinized, they are 
used as Latin words, as Vernonia, after Vernon, an early English 
botanist. 

It would seem that scientific considerations should dictate that 
the practice of naming genera after persons should be discontinued 
since such names do not reflect the taxonomic characteristics 
of the plants so designated. Sometimes these "personal-honor" 
genera are very odd or even ridiculous, as indeed are the names 
of many persons. 

Families, Orders, Classes. Following these conceptions and 
this general plan of grouping we find it convenient to gather all 
genera into appropriate families, families into orders, orders into 
classes, and classes into divisions, involving progressively higher 
and higher (or broader) groupings. It will be observed that this 
whole matter may be compared to several series of compartments 
or pigeonholes within progressively larger compartments with the 
respective limits of each series more or less clearly marked. The 
species are the smallest pigeonholes, and there are subdivisions 



THE CLASSIFICATION OF PLANTS 143 

of the next larger pigeonholes, that is, genera, and genera, in turn, 
are but subdivisions of still larger compartments, that is, families, 
and so on, ending with divisions which represent the broadest of 
all of the subdivisions and contain all of the other pigeonholes 
of all grades. The divisions or " branches " may therefore be 
regarded as the primary or major groups or subdivisions in plant 
classification. 

The Complete Classification. With such a conception before 
us we readily see that each and every plant must occupy a certain 
series of such groups or pigeonholes, and that all such plants taken 
together constitute the vegetable kingdom. Each plant may be 
found in a certain definite position in this classification, just as a 
given pamphlet may be located in a certain building (library), 
in a certain room in that building, in a certain alcove, on a 
certain shelf, and in a certain portfolio, etc., if the library is well 
classified. 

We may now conveniently summarize our discussion of clas- 
sification and the commonly used groups or subdivisions in the 
classification of flowering plants as follows: 

Species consist of individual plants 
Genera are composed of species 
Families are collections of genera 
Orders are collections of families 
Classes are collections of orders 

Divisions or branches are collections of classes 

The Vegetable Kingdom is a collection of plant divisions. 

From this it follows that: 

Every plant belongs to some species 
Every species to some genus 
Every genus to some family 
Every family to some order 
Every order to some class 

Every class to some division, and 

All plant divisions to the Vegetable Kingdom. 

So the Vegetable Kingdom is looked upon by botanists as being readily 
subdivided into 

Divisions (or Branches), as Spermatophyta, seed plants 
Classes (also subclasses), as Dicotyledoneaej dicotyledons 
Orders (also suborders), as Myrtales, the myrtles 
Families (also subfamilies), as Myrtaceae, myrtle family 
Genera, as Eucalyptus 

Species, as globulus, beginning with the largest or most broadly 
differentiated group, the division, and recording in order the regular sub- 



144 FLOWERS AND FLOWERING PLANTS 

divisions to the smallest or most narrowly differentiated group, the species. 
This is the outline or framework which will be used in the classification of 
flowering plants in this book. 

PLANT RELATIONSHIP AND NOMENCLATURE 

Further Ideas Concerning Relationships. Now that we have 
an outline of classification before us we can point out some addi- 
tional practices dealing with the relationship and classification of 
flowering plants. The plants belonging to any one of the above 
subdivisions are regarded as being more closely related among 
themselves than they are to the plants of the next higher group 
For example, the plants of a series of families within a given order 
are more closely related to each other than they are to the planks 
in a series of families in a different order. This means that the 
relationships between orders are more distant than between fami- 
lies, and that, in general, the degree of remoteness of relation- 
ship increases as we go up the scale of subdivisions, and that the 
degree of closeness of relationship increases as we go down the 
scale. 

Value of Names. The necessity of having names for the thou- 
sands of objects with which people are concerned is so obvious 
that it needs no argument. Stop for a moment to observe how 
universal and how early in life is the recognition of such necessity 
characteristic of human beings. Extended refinement in the 1 
tendencies to classify things are indeed attributes which are 
important elements in distinguishing man from all other animals. 
Nomenclature (naming) and taxonomy (classification) are in fact 
prominent factors in the superior intelligence of the human race 
in general and are outstanding incidents of the daily life of 
mankind. 

Nomenclature and Taxonomy. The naming (nomenclature) 
and the classifying (taxonomy) of the objects known to man are 
prominent phases of science in general, but nomenclature and 
classification must be done systematically or else great confusion 
would result. Can you picture the confusion in a great depart- 
ment store in the absence of a carefully named, classified, and 
systematically arranged collection of goods? If you will follow 
out such thoughts in other directions you will become impressed 
with the necessity and the great practical advantages of system- 
atic nomenclature and classification in daily life. But when 
scientists attempt to apply these principles and these methods to 



THE CLASSIFICATION OF PLANTS 145 

rocks, to birds, to insects, to bones, to medicines, and to animals 
and plants many folks throw up their hands in consternation 
with some such expression as: "O, that is too much for me," or 
"That is technical, " or "That is science and I do not want any- 
thing to do with it." Such an attitude is usually a confession of a 
lack of desire to learn truth in an orderly manner. Science and our 
knowledge of science, as well as knowledge in general, can grow 
and improve only by giving due regard to these things. 

We should riot understand because the botanist must have 
names for plants and because plants and plant phenomena must 
be classified, that that is all there is to botany, and that all that 
a botanist knows is merely the names of plants and the termi- 
nology that is necessary to find the names. This is too often the 
opinion of educated folks as well as of the ignorant, due perhaps 
to the fact that the names of plants are quite different from the 
names of other objects. 

Origin and Nature of Names of Plants. Many people dislike 
the names of plants because they appear to be "long and difficult 
to pronounce/' or because they are "Latin or Greek" and such 
languages are "dead." These can scarcely be admitted as 
excuses for an aversion to botanical nomenclature because many 
plants have very short, terse names. And, in reality, much of the 
so-callod English or " common" language, as well as the language 
of science, is merely Latin or Greek transformed to a greater or 
lesser degree. Science is rapidly making over the world and 
systematizing the knowledge about the world so we should not 
be afraid of scientific matters, but should endeavor to learn as 
much as possible about the facts and principles of science. 

Common Names Are Often Confusing. Most people demand a 
" common" name for each plant, meaning by that that we should 
have a name for each plant in the language of the region in ques- 
tion. This is done in many places and for many plants, but, of 
course, the "common" name for a certain plant in English would 
not be a common name in French, Italian, Russian, Or German 
for the same plant. And, furthermore, a given plant often has 
many different common names in the same locality of a given 
country, a condition that tends toward the development of a 
decidedly narrow view of plant life, if no better means of catalog- 
ing were at hand. 

Stability of Nomenclature Is Desired. For many years the 
botanists of the world have endeavored to work out a scheme 



146 FLOWERS AND FLOWERING PLANTS 

whereby the names of plants would be the same in all countries 
and districts, irrespective of the languages or dialects spoken in 
those places. Such a plan is now widely adopted, and it has been 
agreed, furthermore, that the names of all plants shall be in Latin 
or Greek, and that the finished names shall be the same for all 
languages. This has actually been the practice among botanists 
for many years. We have herein the nearest approach to the 
acceptance of a universal language that has yet been obtained. 
This agreement accounts for the fact that the real name or scien- 
tific name for that plant which we call the white oak of the United 
States is the same no matter whether we see it in our own science 
magazines or books or in the scientific publications of any other 
nation on earth. Such names very frequently indicate some 
peculiarity of the plant as well as serving the function of a more 
name. Ideally, this should be more nearly uniformly the case. 
The practical convenience of this whole scheme is obvious. 

The Form of Scientific or Botanical Names. Another point 
which had to be settled in the manner of plant names was just 
what was to constitute the name. Very different methods were 
adopted in bygone centuries to meet the necessity of having 
some means by which different plants might be designated. In 
ancient times, in the absence of a name in the usual modern sense, 
we find that a rather complete description of the plant was 
necessary. Later, shortened but still clumsy and unwieldy 
expressions were used. As more and more plants from distant 
parts of the world became known it became necessary to reduce 
or shorten the matter used in the designations of particular 
plants. It was finally decided that the genus name written with 
the species name should constitute the real name or scientific 
name of a plant. The tendency to write the generic name 
(genus) first, with a capital letter, followed immediately by the 
species name, usually with a small initial letter, has now become 
the world-wide custom. So we say that the scientific name of a 
plant consists of the generic name and the specific name written 
together as a binomial, the generic being the first name, and the 
specific name being the last name. Thus we have Quercus 
alba, the white oak, Quercus borealis, the red oak, Pinus strobus, 
the white pine, Pinus resinosa, the red pine, Pinus rigida, the 
pitch pine, etc. 

Nomenclatorial Practices. Certain similarities and differences 
in the use of names for plants and for human beings may be noted. 
There is now a tendency among Americans to drop the custom of 



THE CLASSIFICATION OF PLANTS 147 

giving "middle" names to children. This is in notable contrast 
to the practice of olden times of giving a series of names to 
children at time of christening, a tendency which is still repre- 
sented in the modern world in some countries. The practice 
persists in the names of the royalty of certain nations. The 
fact that our country looks upon this as an outgrown practice is 
seen in the dropping of all but three of the names in common use, 
and a decided tendency to reduce them still further to two only, 
that is, a first name and a last name. Our practice is to write the 
names of persons with the specific name first and the generic 
name last, as George Brown, Mary Brown, Henry Brown, etc. 
But these are really not specific names and generic names, as they 
arc used in the broad biological sense they are merely names for 
individual human beings. The fact is that George Brown, 
Mary Brown, Henry Brown, and all the other Browns, as well as 
everyone else in the human race belong to the same identical 
genus and species, in the broad biological sense. The above 
names, like other names used in human society, are for the 
individuals of a given species, of the same species, which is Homo 
sapiens. The necessity of having different names for each 
individual of the human species is obvious. It is readily seen 
that this custom is the same as would be practiced by the farmer 
if he wore to have a different name for each individual wheat 
plant in his field, or for each sugar beet in the beet field. We do 
not need to have names for each individual tree in our great 
forests or for each individual grass plant in the great prairie- 
plains region of North America, but the complexities of human 
society and government demand that we attempt to do that for 
the human species as the most important and troublesome 
member of the animal kingdom. 

Linnaeus and Nomenclature. Botanical history indicates 
that Linnaeus, the great Swedish naturalist, was the first biologist 
to use binomial names extensively and consistently for plants. 
He used this as the regular manner in which to designate the 
plants which he described in great numbers and about which he 
wrote so extensively. Binomials, in fact, had been sporadically 
suggested and used to some degree long before his time, but his 
monumental work of 1753, the " Species Plantarum," marks the 
clear establishment of this practice on a wide basis. 

Scientific Names Most Definite and Reliable. In concluding 
this discussion of plant names, we would urge students and others 
to learn the real names, i.e., the technical names for plants, since 



148 FLOWERS AND FLOWERING PLANTS 

they constitute a much more reliable clue to the identity of 
plants than do common or " vulgar" names. These names 
appear complex and difficult to learn only because they are new 
or uncommon in the language of the street. Surely we should 
not be startled by such names as Prunus, Abies, Larix, Populus, 
Lithospermum, Primula, Taxodium, Poa, Crepis, Munroa and 
Pseudotsuga, or even Lepargyraea, etc., when we use very com- 
monly such names as Rosa, Clematis, Syringa, Cyclamen, Gera- 
nium, Delphinium, Ageratum, Calendula, Rhododendron, and 
Chrysanthemum. The fact that all such names are current, 
scientifically, in all lands and districts for the respective plants in 
question should constitute a powerful argument in favor of 
abandoning all so-called common names, and adopting and 
using only the scientific names for plants. 



CHAPTER XI 

PRINCIPLES OF CLASSIFICATION OF FLOWERING 
PLANTS 

Reference has been made at various places in the preceding 
chapters to the features of flowers that are regarded as indicating 
the primitive nature and the more advanced nature of flowering 
plants. We may now bring these principles of classification 
together and consider them along with those other somatic 
features of flowering plants which are regarded as indicating 
relationships among these plants and which, therefore, are of 
guiding value in the arrangement of the groups in a natural or 
phylogenetic system of classification. 

Lack of Sufficient Information. The student must under- 
stand that the information relative to the life history and mor- 
phological details of flowering plants that we now possess is 
still very incomplete and that it is insufficient to establish clearly 
many of the detailed relationships that are necessary for the 
formulation of an accurate and complete natural system of 
classification. Many years must corne and go bringing great 
volumes of data before botanists can propose a system of classi- 
fication of flowering plants that will be truly natural and phylo- 
genetic in all its details. Such a perfect system may perhaps 
never be possible because of obstacles which need not be noted 
here. 

THE QUESTION OF ORIGIN 

Origin of Flowering Plants. The question of the origin and 
descent of living groups appears to be no more deeply hidden in 
the complex workbof organisms than for flowering plants. The 
gap between ferns and seed plants was one of the last to be 
bridged by students of plant evolution. The immediate group 
of higher plants from which seed plants and flowering plants 
have probably developed is still very much of an enigma. Solu- 
tions to this problem, which has puzzled botanists for many 

149 



150 FLOWERS AND FLOWERING PLANTS 

decades, have frequently been offered during the past 50 years, 
but no convincing proof is at hand for any of the contentions. 

The Bennettitales. The opinion that the more nearly imme- 
diate ancestors of flowering plants were woody forms has been 
widely held for several years. But when investigators set out 
to determine if there are woody plants to be found among the 
wealth of fossil remains that might throw some light upon the 
problem much uncertainty arises. Certain studies culminated 
in the announcement that members of the fossil group Bennet- 
titales were fern-like, pine-like, woody plants and that they 
produced seeds in structures that meet very well our hypothetical 
conceptions even of primitive flowers. These plants are evi- 
dently also closely related to the ancestors of our modern cycads 
and conifers. The staminate and pistillate structures were borne 
in cone-like groups more or less like the flowers of one of our 
modern magnolias, but there were also a number of details in 
the anatomy of the " flowers " of these early flowering-plant 
relatives, especially of their stamens, that were more nearly fern- 
like than anything else. Some of these "flowers" show a well- 
developed perianth also. Clearly these plants appear to be more 
or less intermediate between ferns and seed plants in general 
and flowering plants in our modern conception. 

Since the announcement of these very important discoveries, 
botanists rather generally have accepted the idea that flowering 
plants have sprung from Gymnosperms that were more or less 
like the Bennettitales. These, and the immediate ancestors of 
the flowering plants whatever they were, disappeared from the 
earth long ago; but the latter were probably much like theso 
Bennettitales now represented only in fossil form. 

Evidence from Serum Analysis. The ingenious and note- 
worthy methods of serum analysis of flowers developed by 
C. Mez in Germany have yielded many suggestive findings in 
regard to the origin and probable development of flowering 
plants from ancestors similar to our modern conifers, Coniferales, 
and they tend to support numerous features of the Besseyan 
System that were worked out by the use of other criteria. 

Woody and Herbaceous Types. Agreement is becoming 
general that the woody members, Magnoliaceae, of the buttercup 
group, Ranales, most nearly resemble the ancient types and they 
are, therefore, to be considered the most primitive of all modern 
flowering plants. The Besseyan system of classification reflects 



CLASSIFICATION OF FLOWERING PLANTS 151 

this point of view and it treats the flowering plants as a single 
series in so far as their origin is concerned. This system, even 
in its last form, is in reality a modification of the Bentham and 
Hooker arrangement after which it is patterned. 

Relation between Dicotyledons and Monocotyledons. Investi- 
gations of more recent years tend to substantiate the thesis that 
the Dicotyledons were the first types to appear and that these 
gave rise to the Monocotyledons at a somewhat later period. 
The woody buttercups, Ranales, are the earliest or most primitive 
group from which the Monocotyledons and the two branches of 
Dicotyledons have diverged. An abundance of evidence from 
the study of the vegetative as well as of the floral morphology 
and serum analysis of flowering plants by many investigators 
in America, Germany, England, and Italy, during the past 20 
years would seem to establish these features as a very plausible 
hypothesis. 

Bessey's Principles. Bessey restated and expanded a series 
of "dicta" as a means of giving concrete expression to the 
guiding principles that have been derived from a survey of the 
investigations upon the ancestry and descent of flowering plants. 

A more recent (1926) publication by Hutchinson, of Kew Gar- 
den, England, adopts essentially the same ideas and principles of 
classification as those included in the older (1915) Besseyan 
system. But Hutchinson separates the Dicotyledons into two 
main series, one of which is woody and diverges from Magnoliales, 
the other is herbaceous and diverges from Ranales. 

The dicta or principles may be conveniently treated under two 
subdivisions, namely, those that pertain to the general anatomy of 
the vegetative body of flowering plants, and those that pertain to 
the flower and its work. The following treatment is somewhat 
modified and extended from the proposals of Bessey, Hutchinson, 
and others. 

VEGETATIVE ANATOMY 

The Vascular Bundles. Plants with the collateral fibro- 
vascular bundles of the stem arranged in the form of a hollow 
cylinder, with pith on the inside and cortex on the outside of the 
cylinder, as in magnolias and oaks, are more primitive than plants 
with fibrovascular bundles scattered through the stem with no 
clearly set out pith and cortex as in palms and lilies. The 
latter are Monocotyledons, and they are probably derived from 
the former type which are Dicotyledons. 



152 FLOWEKS AND FLOWERING PLANTS 

Woody versus Herbaceous Species. The woody stem, 
developed by the formation of much fibrous tissue in the fibro- 
vascular bundles is more primitive than the herbaceous stem 
with a minimum of fibrous tissue. Woody plants, shrubs and 
trees are primitive. Herbaceous plants are derived from woody 
ancestors. Trees, in the usual sense, are primitive, and herbs 
have developed or descended from trees. 

Climbers (lianas) are younger than erect shrubs and trees from 
which they appear to have been developed in response to environ- 
mental relations. 

Simple and Branched Stems. Simple or unbranched steins 
are primitive, and branched stems are a later development 
from these. 

Leaf Features. Simple leaves are primitive ; compound leaves 
are derived and higher. Whorled or opposite leaves are derived ; 
solitary or spirally arranged leaves are primitive. Primitive 
plants produced evergreen leaves, but deciduous leaves were 
developed later. Leaves with reticulated or netted veins appear 
to be primitive and leaves with parallel venation are probably 
a later development. 

Duration of Life. Perennials are primitive, biennials and 
annuals have developed later. 

FLORAL ANATOMY 

The Inflorescence. Plants that produce solitary flowers are 
primitive and plants with many-flowered inflorescences are later 
and higher. 

Spiral and Cyclic Flowers. The spiral type of flower, as in 
Magnolia, is primitive, and the cyclic type, as in lilies, Lilium, 
and mints, Mentha, is later and derived from the former. 

Number of Parts. Plants with flowers with many or an indefi- 
nite number of floral parts or elements, as in buttercups, Ranun- 
culus, and magnolias, Magnolia, are primitive, and plants with 
few parts or a definite number of parts, as in gentians, Gentiana, 
and bluebells, Campanula, are higher. These changes are 
brought about through increasing parental care and the resultant 
sterilization of many essential organs of the flower. 

Petaly and Apetaly. Flowers with petals, as in geranium, 
Geranium, are primitive and normal, and flowers without petals, 
as in oaks, Quercus, and birches, Betula, are derived from the 
former by loss or reduction of the parts. 



CLASSIFICATION OF FLOWEKING PLANTS 153 

Polypetaly and Sympetaly. Flowers with the perianth parts 
(sepals and petals) separate, i.e. not ''united " or "grown 
together, " as in buttercups, as has been explained in an earlier 
chapter, are earlier types, and flowers with perianth parts 
' 'united," as in primroses, Primula, blueberries, V actinium, 
honeysuckles, Lonicera, etc. are later or higher. 

Actinomorphy and Zygomorphy. Flowers that are radially 
symmetrical or actinomorphic, as in arrowheads, Sagittaria, 
lilies, Tulipa, irids, Iris, flaxes, Linum, potato, Solanum, etc. 
are primitive or early in the developmental sense, and flowers 
that are bilaterally symmetrical or otherwise unsymmetrical 
or zygomorphic, as in orchids, Orchis, beans, Phaseolus, mints, 
Nepeta, violets, Viola, and snapdragons, Antirrhinum, are regard- 
ed as much later forms. 

Hypogyny and Epigyny. Flowers with a superior ovary (hypo- 
gyny) as in buttercups, Ranunculus, etc. onions, Allium, grasses, 
Poa, mustards, Brassica, primroses, Primula, and morning- 
glories, Ipomoea, etc. are more primitive than flowers with an 
inferior ovary (epigyny) as irids, Ins, banana, Musa, honey- 
suckle, Lonicera, and composites, Helianthus, Aster, etc. 

Apocarpy and Syncarpy. Flowers with separate pistils and 
carpels (apocarpy) as in buttercups, Ranunculus, etc., are more 
primitive, and flowers with united carpels (syncarpy) as in 
lilies, Lilium, nightshades, Solanum, phloxes, Phlox, etc. are 
higher and have been derived from the former. The poly- 
carpous flower (i.e. a flower with many carpels) is the earlier 
condition and the oligocarpous flower (i.e. a flower with a few 
carpels that are usually united) is derived from it. 

Concerning Stamens. Primitive flowers have many separate 
stamens, i.e. they are polystemonous and apostemonous, and 
later flowers have fewer stamens, i.e. they are oligostemonous, 
and these show a tendency to become united, synstemonous. 
Primitive flowers typically produce more or less powdery pollen, 
and higher flowers tend to produce waxy or coherent pollen. 

Perfect and Imperfect Flowers. Perfect, or monoclinous 
flowers, i.e. flowers that have both stamens and pistils, as in 
buttercups, Ranunculus, roses, Rosa, cotton, Gossypium, etc. are 
more primitive than those that are imperfect or diclinous, i.e. 
have their stamens and pistils produced in different flowers, 
as in oaks, Quercus, wild rice, Zizania, ashes, Fraxinus, and 
cottonwoods, Populus. 



154 FLOWERS AND FLOWERING PLANTS 

Monoecious and Dioecious Plants. There are two types 
among diclinous plants, i.e. plants with imperfect flowers. One 
of these is the monoecious type, in which stamens and pistils 
are produced in different flowers upon the same individual plant, 
as in oaks, Quercus, wild rice, Zizania, birches, Betula, etc. The 
other is the dicecious type, in which the stamens and pistils are 
produced in different flowers and these are borne by entirely 
different and separate plants, as in the ashes, Fraxinus, cotton- 
woods, Populus, willows, Salix, boxelder, Acer, etc. The monoe- 
cious condition is regarded as the more primitive, and the 
dicecious condition is considered to be a later development. 

The Question of Seeds. Plants that produce many seeds per 
flower are regarded as relatively primitive, and those that pro- 
duce few seeds per flower are derived. Many higher plants 
have come to produce a single seed per flower, as in the com- 
posites. The seed with endosperm is regarded as indicating a 
lower relationship than is indicated by a seed without endosperm. 
The seed with a small, straight embryo imbedded in endosperm 
is more primitive than the seed with a large curved or coiled 
embryo and with little or no endosperm. 

Monophylesis versus Polyphylesis. The above principles 
when applied to the classification of flowering plants result in 
the arrangement of the groups in a manner very different from 
that of the Englerian plan, the most widely accepted and used 
system for many years. The system of Engler teaches that the 
Monocotyledons are more primitive than the Dicotyledons and 
that both groups have had a polyphyletic origin. That system 
also regards the flowers without petals as primitive types from 
which the petaliferous types have developed later. The 
latter is a point of view also recently expressed by Wettstein, 
The de Candollean, Bentham and Hooker, and Besseyan systems 
are exactly contradictory in regard to both of these points. 
Bessey regarded petaly as the original and normal condition, 
and apetaly was derived from this at a later date. The evidence 
that has been accumulating for a quarter of a century would 
seem to indicate that the conception of de Candolle and Bessey 
is the more nearly proper one and that Engler is doubtless in 
error when he places the Apetalae and Amentiferae at the begin- 
ning of his system instead of associating the plants of those 
groups with the higher groups to which they appear to be 
related. However, this problem is still far from being settled. 



CLASSIFICATION OF FLOWERING PLANTS 155 

Position of Apetalous Species. Certain investigators have 
made a strong case for the treatment of Apetalae and Amentiferae 
as derived rather than primitive on the basis of pollination and 
insect visitation. Entomophilous or insect-pollinated flowering 
plants are primitive, and anemophilous or wind-pollinated plants 
are derived from the former by a process of reduction. Evidence 
is at hand that would support the contention that such plants 
as grasses, sedges, and ragweeds, which are apetalous, and oaks, 
birches, cottonwoods, and willows, which are amentiferous as 
well as apetalous, and mostly anemophilous, are, indeed, to be 
regarded as the very highest of all flowering plants, outranking 
the orchids, Orchidaceae, and composites, Compositae, that for 
years have been regarded as the most diversified and highest of 
Angiosperms. It would appear that reduction of the perianth, 
with the consequent loss of attractiveness for pollinators has gone 
so far as to result in the development of a totally different method 
of pollination, namely anemophily. The fact that the Amentif- 
erae produce ovaries with two or more united carpels is an 
additional argument against the primitive nature of these plants, 
and in favor of their reduced and derived nature. Primitive 
flowering plants produced flowers with many separate carpels, 
according to present evidence. 

Engler and Bessey on Epigyny. The Englerian system gives 
little weight to epigyny in the arrangement of the groups, the 
epigynous species being more or less distributed among hypog- 
ynous species in the same groups. The system of Bentham and 
Hooker and the Besseyan system make much of epigyny in 
the arrangement of the orders and families. The major groups 
Epigynae, Inferae, etc. have been conspicuous subdivisions 
of the latter schemes of classification for many years. The 
arrangement (of Dicotyledons) proposed by Hutchinson also 
gives considerable weight to epigyny as opposed to hypogyny 
in the grouping of the different series. 

The Findings of Morphology. The systems of classification 
for flowering plants proposed by Bessey and Clements in America 
and by Hallier and Hutchinson in Europe have the great merit of 
support front much comparatively recent work in morphological 
botany as well as from an examination of the evidence afforded by 
fossil remains and serum analysis. The Besseyan system, when 
it is portrayed in graphic form by means of the floral formulae 
already described, becomes extremely useful for the presentation 



156 FLOWERS AND FLOWERING PLANTS 

of an introduction to many of the most significant features in the 
structure, morphology, general biology, and classification of 
flowering plants when arranged and expanded in the form of 
the chart first devised by Clements. 

THE OUTLINE SHOWN BY THE CHART 

The flower chart is in reality a condensed and graphic key to 
the families represented, depicting many of the significant charac- 
teristics of the several families that, treated in the usual manner 
of a manual, would cover many pages of descriptive matter in 
fine print. The chart also presents a much more evident and 
impressive idea of relationships than is possible to show in the 
descriptive manual. The beginning student rarely if ever senses 
the fact that the arrangement of the groups in a manual is 
meant to reflect a notion of relationship. Even when that fact 
is presented to him he has difficulty in forming much of a knowl- 
edge as to the nature of the groups and relationships involved 
because they are so completely hidden among the pages of the 
book. 

The Three Lines of Development. The chart is prepared in 
three units one of which, 1 on the left, represents the Monocoty- 
ledons, the central and right hand units, 2 and 3 representing 
the two main series of Dicotyledons of the Besseyan system. 
Lines of development are used to represent certain ideas of 
origin of the whole series and their divergence from the Ranaks, 
as well as relationships among the subdivisions of each of the 
three main series. The Monocotyledons are represented as orig- 
inating from the Ranaiian plexus standing at the axis of the 
whole series. The main line of Monocotyledons begins with the 
arrowheads, Alismalex, lying next to Ranales, and in turn higher 
up we see the lilies, Liliales, irids, Iridales, and the line termi- 
nates in the orchids, Orchidales. The important side branches 
of the monocotyledonous series include the arums, Arales, palms, 
Palmaks, water weeds, Hydrales, and the grasses and their kin, 
Graminales. This is a fairly well standardized treatment of the 
Monocotyledons, although the order names and the inclusions 
of the various orders are not exactly the same in the Besseyan 
system as in other arrangements. After all, such details as the 
latter are of no interest or value to the beginner who has a rather 
big task anyhow to become familiar with the orders and families 



CLASSIFICATION OF FLOWERING PLANTS 157 

that are best known and about whose systematic position there 
is least disagreement among botanists. 

The Dicotyledon Series. The series of Dicotyledons on the 
right, 3, begins with the Ranales and leads into three groups 
of orders including the mallows, Malvales, geraniums, Geraniales, 
violets, Theales, (Guttiferales) , mustards, Papaverales, (Rhoeadales) , 
and the pinks, Caryophyllales, in the first group, followed by the 
primroses, Primulales, ebonies, Ebenales, and heathers, Ericales, 
and terminating in the third group of orders including phloxes, 
Polemoniales, gentians, Gentianales, mints, Lamiales, and snap- 
dragons, Scrophulariales. 

The other series of Dicotyledons, 2, constitutes the main axis of 
the whole assemblage of flowering plants and is represented on 
the central chart. This series begins also with the Ranales and 
continues through the roses, Resales, bittersweets, Celastrales, 
parsleys, Umbellales, madders, Rubiales, and terminates in the 
composites, Aster ales. Lateral branches of this line include the 
myrtles, Myrtales, cactuses, Cactales, and the loasas, Loasales, 
from the roses, the maples, Sapindales, from the bittersweets, and 
the harebells, Campanulales, from the madders. 

Extent of the Chart. The chart as we have commonly used 
it contains about 100 families arranged in about 30 orders. A 
knowledge of 100 families of flowering plants is a fine start for 
anyone in the field of systematic botany. There are probably 
many botanists who work in other branches of our subject that 
are not able to recognize at sight anywhere near this number of 
flowering-plant families. The great advantage of the system 
and of our methods of using it is in the short cut it affords to the 
family, and especially to the mastery of the floral earmarks of 
families by means of the graphic formulae. 

Cross-lines on the Chart. When the chart with its three 
branches is completed with the orders and families neatly printed 
and with their formulae carefully sketched opposite them, then 
lines are drawn across the chart that divide the families into 
smaller groups bounded by the various lines. For example one 
cross-line is so drawn as to separate the hypogynous (below the 
line) and the epigynous (above the line) families, another one 
separates the polypetalous from the sympetalous groups, still 
another cross-line separates the actinomorphic groups from the 
zygomorphic groups, and a fourth line marks the dividing line 
between apocarpous and syncarpous families. The three main 



158 FLOWERS AND FLOWERING PLANTS 

lines of flowering plants including Monocotyledons and the two 
lines of Dicotyledons are charted side by side so that the four 
cross-lines are continuous as they cut across the whole chart 
from side to side. Here and there some of the lines cross each 
other vertically and this serves to differentiate still further 
certain groups of families among which the desired one may be 
located by the inspection of a very few formulae. The value x of 
the cross-lines lies in the fact that they serve much the same 
function as the subdivisions in an ordinary printed key in leading 
one to an increasingly smaller group of forms among which the 
family containing the flower in question may be found. The 
location of a family on the chart with a formula to which the 
structure of a given flower conforms, thus becomes a very inter- 
esting quest that is rapidly perfected as one's knowledge of the 
families increases until by and by it becomes possible to discard 
the chart altogether, or to refer to it only occasionally when new 
families are encountered. 

Care in Using the Chart. The successful use of the chart in 
locating the family to which an unknown plant belongs depends 
largely upon the thoroughness with which the structure of the 
flower is worked out. Naturally this determines the proper 
formula to look for and if a misleading or incomplete formula 
has been worked out one cannot expect to find the proper family 
as readily as would be possible with greater care in flower analysis. 
These facts tend to impress the essential morphology of family 
types (as indicated by flower structure) upon the mind of the 
worker in a lasting manner. 

When the formula derived from the analysis of the flower has 
been matched with that of a certain family on the chart then 
one must go to the manual where the genus and species may be 
found for the further classification of the plant. 

Extension of the Chart Method. The chart method here used 
goes only as far as the family, but it has been found that the 
method is tremendously helpful to that point as compared to 
the usual laborious route through keys and through the inspection 
of long family diagnoses in the books. The scheme might pos- 
sibly be extended to include the genera of various families, but 
the plan might become so complicated if expanded to that degree 
as to defeat its purpose except for more advanced interests. 

Explanation of Symbols Used on the Chart. The most of the 
relatively few symbols that are necessary to write the formulae 



CLASSIFICATION OF FLOWERING PLANTS 161 

which one may arrive at the name of the ultimate member of the 
group. A synopsis is primarily a taxonomic summary of charac- 
ters by which the members are classified. A key is concerned 
chiefly with quick identification; a synopsis is concerned chiefly 
with showing relationships." Referring again to the floral 
formulae and flowering-plant chart, it may be observed that keys 
are more or less comparable to the formulae, synopses to the 
chart. 

Types of Keys. There are various kinds and combinations of 
keys and synopses. A key may be so constructed as to indicate 
natural relationships or affinities, or it may be drawn on a purely 
artificial basis, i.e., may disregard natural or phylogenetic 
relationships. Keys may be plain or illustrated, simple or 
complex ; they may be based upon flowers alone or upon vegeta- 
tive characteristics alone; or they may combine various charac- 
teristics shown by the plants classified. A key may consider 
only the color of the flowers or the number of parts in the flowers, 
or it may be based upon fruits and seeds. A vegetative key may 
include only buds, or leaves, or stems, or all sorts of combinations 
of these. Even different environmental requirements are fre- 
quently included in keys. 

In constructing a key, one selects the most prominent or 
contrasting characteristics to distinguish the broadest or primary 
divisions, and then the subdivisions of various degree may be 
identified likewise by lesser contrasting features or by charac- 
teristics of lower rank or of more detailed and restricted nature. 
The simplest key includes a single pair of contrasting statements, 
for example: 

Leaves opposite Genus Acer, maples 

Leaves alternate Genus Quercus, oaks 

Or if the relatively simple key is to differentiate a larger number 
of groups or categories, say species, as well as genera, then addi- 
Jjonal statements must be entered in order to distinguish the 
plants of the smaller or more subordinate groups, for example: 

Leaves opposite Genus Acer, maples 

Leaves simple Species saccharum, sugar maple 

Leaves compound Species negundo, box elder 

Leaves alternate Genus Quercus, oaks 

Leaves with rounded lobes . Species alba, white oak 
Leaves with pointed lobes . Species velutina, black oak 



162 FLOWERS AND FLOWERING PLANTS 

In the practical construction of such keys as the above, the words 
" genus" and " species" would be omitted. They are included 
here only to emphasize the primary and secondary groups or 
categories used. A key that embraces many genera or species 
must, of course, include many more contrasting or comparative 
statements and necessarily becomes more and more complex 
as the details increase. 

The Bracket Key. On the basis of fundamental structure, there 
are two types of keys, the bracket key and the indented key. Both 
of these are very useful. The mechanical structure of the bracket 
key may be illustrated by the following " diagrammatic " example 
to include seven hypothetical species: 

1. Flowers white 2 

1. Flowers red . 5 

2. Leaves opposite . 3 

2. Leaves alternate . . 4 

3. Flowers 3-parted Species 1 

3. Flowers 5-parted . Species 2 

4. Leaves simple. Species 3 

4. Leaves compound Species 4 

5. Flowers in spikes Species 5 

5. Flowers in raceme < 6 

6. Fruit white . . . Species 6 
6. Fruit red. . . Species 7 

The Indented Key. The indented key, in a great variety of 
forms, is the key most widely used and seen in floras and manuals 
throughout the world. The mechanical contrasts between the 
bracket key and the indented key may be illustrated in a simple 
manner by "keying out" the seven species used in the foregoing 
illustration of the bracket key, as follows: 

Flowers white 
Leaves opposite 

Flowers 3-parted . . Species 1 

Flowers 5-parted . ... Species 2 

Leaves alternate 

Leaves simple . ... Species 3 

Leaves compound . . . Species 4 

Flowers red 

Flowers in spikes . Species 5 

Flowers in racemes 

Fruit white Species 6 

Fruit red ... Species 7 



CLASSIFICATION OF FLOWERING PLANTS 163 

It will be readily noted from the foregoing examples that the 
indented key leads more directly to the various subdivisions and 
is more easily " followed through/' This is because the inter- 
connections between the various subdivisions of the indented key 
are so grouped or spaced as to be more easily and accurately 
read they lead more directly to the several species involved. 

When the successive divisions of a key are always in pairs, the 
key is said to be dichotomous* Both indented and bracket keys 
are often constructed in this manner. 

Longer Keys. In keying out a great many plants, the key may 
become very long and complicated and thus may be more or less 
difficult to follow, because the contrasting subdivisions may be 
separated widely, sometimes even by several pages. The diffi- 
culties incurred because of this situation are relieved somewhat by 
using certain letters, numbers, signs, or other symbols to mark 
the corresponding subdivisions in the keys. An example of this 
useful device, applied to the foregoing simple bracket key, may 
be shown as follows: 

la. Flowers white 

2a. Leaves opposite 

3a. Flowers 3-parted .... . Species 1 

36. Flowers 5-parted . . Species 2 

26. Leaves alternate 

3a. Leaves simple Species 3 

36. Leaves compound . . . Species 4 

16. Flowers red 

2a. Flowers in spikes . Species 5 

26. Flowers in racemes 

3a. Fruit white. Species 6 

36. Fruit red Species 7 

An example of an actual indented key, long in use, is the 
following key 1 to the genera of the pink family, Caryophyllaceae, 
of the Rocky Mountains. 

Sepals united, forming a tubular or ovoid calyx. 
Ribs or nerves of calyx 10 or more. 

Calyx-teeth foliaceous 1. Agrostemma. 

Calyx- teeth short. 

Styles 3 2. Silene. 

Styles 5 3. Lychnis. 

Ribs or nerves of calyx 5. . 4. Saponaria. 

1 COULTER, J. M. and A. NELSON, New Manual of Botany of the Central 
Rocky Mountains, p. 180. American Book Company, 1909. 



164 FLOWERS AND FLOWERING PLANTS 

Sepals distinct or nearly so. 

Petals deeply emarginate or bifid. 

Capsule dehiscent to the base; styles mostly 3 5. Stellaria. 

Capsule opening at summit only, by teeth, styles 

mostly 5 . 6. Cerastium. 

Petals entire or barely emarginate. 
Stipules wanting 

Styles 5 ... . . . . .... .7. Sagina. 

Styles 3. 

Seeds not appendaged at the hilum . . 8. Arenaria. 

Seeds with an appendage (strophiole) ... 9. Moehringia. 

Stipules present, usually scarious and conspicuous 

Capsule opening by 3 valves to the base . 10. Spergulana. 

Capsule indehiscent, or essentially an achene 11. Paronychia. 

Coulter and Nelson's key 1 to the species of Populus, poplars, 
aspens, cotton woods., in the Rocky Mountains illustrates a 
relatively simple key of the indented type that is based on the 
characteristics of the leaves alone, as follows: 

Petioles flattened laterally. 

Leaves suborbicular . . .1. P. tremuloidcs. 

Leaves broad, more or less deltoid. 

Abruptly acuminate, crenately serrate 2. P. occtdentalis. 

Gradually acuminate, deeply smuate-dentato . 3. P. Wislizemi. 
Petioles roxind or furrowed. 

Leaves pale beneath . . 4. P. balsamifera. 

Leaves green, scarcely lighter beneath. 

Oblong-lanceolate 5. P. anguslifolia. 

Ovate, abruptly long-acuminate 6. P. acuminata. 

The student must understand that keys, even at their best, 
are but selected assortments of only a few of the characteristics 
of the group of plants involved. He should know that he is 
likely to find exceptions to the statements contained in them, 
but these should not discourage him or lead him to doubt the 
value of the work in question. Variation is one of the greatest 
laws of biology. Keys and taxonomic diagnoses can attempt to 
record only the outstanding or the usual and most distinctive 
features of plants. It would not be at all practical or useful to 
state all the possible exceptions that may be encountered. The 
larger the group represented in the particular classification, the 
greater the number of details that must be considered and the more 
likely it will be that allowance will have to be made for the 
possible exceptions to the statements in the key. Only by the 

1 Ibid., p. 127. 



CLASSIFICATION OF FLOWERING PLANTS 165 

gradual mastery of a knowledge of the " typical characteristics" 
that delimit the natural groups of flowering plants, and with 
careful consideration of the possibility of variations and excep- 
tions to be noted in all diagnoses, can one build up a growing 
familiarity with the limitations of the natural groups that con- 
stitute the flora of the world. 

MANUALS AND FLORAS 

The only reliable scientific guide to the flora of a given area, 
whether small or large, is likely to be so technical as to discourage 
all but the most enthusiastic and serious student of nature. 
Taxonomy must utilize a critical and technical terminology to 
accomplish its complicated objectives. There are always many 
more species of plants in an area than is apparent to the uniniti- 
ated; and when all these are systematically treated in the usual 
scientific manner, with the necessary terminology to differentiate 
them and the technical names to designate them, the popular- 
minded person becomes lost in the "maze of scientific j argon " 
and is likely to think that it is all useless. 

A manual or flora is an analytical and descriptive presentation 
of the nature and the names of the plants of the area in question. 
The most common use of such a work is to find the names of 
plants in order that they may be referred to in a definite and 
intelligible manner. Manuals are supplied with keys to the 
major groups as well as to the subordinate categories, down to 
the species. Sometimes the keys and the descriptions of the 
species are accompanied by illustrations. A manual usually 
covers a relatively large territory or section of a country, as is 
illustrated by Britton's Manual of the Flora of the Northern 
States and Canada and Gray's New Manual of Botany, covering 
northeastern United States. A local flora deals in the same way 
with a more limited area, as a state, county, or even a single 
valley; Rydberg's Flora of Montana and Flora of the Black Hills 
of South Dakota and Mackenzie and Bush's Manual of the Flora 
of Jackson County, Missouri are examples of local floras. 

Besides keys and synopses to the families, genera, and species, 
many manuals also include descriptions of all these groups, as 
well as notes on the range or geographical distribution, habitat 
characteristics, and other features that aid in the identification 
of the plants. The student must understand that all these helps 
are the product of the wide experience and knowledge of the 



166 FLOWERS AND FLOWERING PLANTS 

authors. He must learn to allow some leeway in regard to the 
descriptive material and to understand the situation if he finds 
individual plants that do not exactly "fit into" the keys and 
descriptions of his manual or flora. Keys and diagnoses are so 
constructed as to illustrate the average of many individuals, the 
species, in other words. This means that it is seldom safe to rest 
one's identification upon a single specimen, unless one's knowl- 
edge already goes far beyond that particular individual. In 
short, variations in size, range, habitat, and morphological 
characteristics of the vegetative body, and even of the flowers 
and fruits, are likely to be found among the individuals of all 
species of flowering plants. Only the wide experience and 
seasoned judgment that come with years of taxonomic work can 
produce competence in this line of technical work or in any other 
branch of science. 

Study of Selected Families. We may now consider the general 
nature of a number of families of flowering plants selected to 
illustrate the foregoing principles of classification and arrange- 
ment of orders and families. Most of these orders may be found 
on the chart. The illustrations used in connection with practi- 
cally all of the groups included are selected with the idea of 
portraying a few of the details of the foliar, floral, and fruiting 
habits of the respective families. 



CHAPTER XII 

SELECTED ORDERS AND FAMILIES OF 
DICOTYLEDONS 

The Dicotyledons are the most varied and numerous of modern 
Angiosperms. They are represented in the flora of the world by a 
great many more types and species than are their close relatives 
and differentiates, the Monocotyledons. The proportion of 
Dicotyledons to Monocotyledons now described is about four to 
one, there being approximately 120,000 species of the former 
and about 30,000 species of the latter. 

Vegetative Nature of Dicotyledons. The stems of Dicoty- 
ledons are typically characterized by the presence of fibrovascular 
bundles arranged more or less in the form of a hollow truncated 
cone with pith in the center and with cortex enveloping the 
outer surface, all of which regions diverge downward from a mass 
of meristematic tissue at the tip of the stem. The lateral 
branches of the stem are developed after the same plan and they 
have essentially the same structure. A short section of such a 
stem or branch may be more or less cylindrical in form because of 
slight taper and in such cases the layers of tissues that make 
up the stem are somewhat of the nature of overlapping organ- 
ically connected cylinders (Fig. 77, B). 

Growth and Length of Life. All of the meristem becomes 
differentiated into permanent tissues in many Dicotyledons 
so that the life of the individual plant is terminated at the close 
of a single growing period, and the plant is therefore called an 
"annual." In many other Dicotyledons a zone of meristem 
persists or remains undifferentiated between the xylem and 
phloem of the fibrovascular cylinder as the individual passes 
into and through the resting period. Such plants are capable 
of continued growth with each successive active period and are, 
therefore, called " perennials. " The xylem portions of the cen- 
tral cylinder in many such plants is built up by the annual 
formation of a new layer of wood over the preceding layer, 
and in this way the stem increases in diameter as well as in height. 

167 



168 



FLOWERS AND FLOWERING PLANTS 



These so-called "annual rings" of perennial Dicotyledons are in 
reality annual layers of wood that are not rings at all, but they 
take the form of the entire individual composed of its main stem 
and all the living branches. They appear as a series of more or 
less perfectly concentric rings only in a cross-section of the stem 
(Fig. 97, B). 

The first or primary leaves (cotyledons) on the stems of Dicoty- 
ledons are usually two in number, and they are opposite. The 

secondary or mature leaves 
are typically netted veined, 
and they are opposite, alter- 
nate, or whorled. 

Floral Pattern in Dicotyle- 
dons. The flowers of 
Dicotyledons are typically 
four-parted (tetramerous) or 
five-parted (pentamerous), 
that is, they have a perianth 
in which there are four or five 
parts represented in the calyx 
and the corolla, or in the calyx 
alone in those flowers which 
lack the corolla (Fig. 97). 
Certain species of the group 
lack petals, and others lack 
both petals and sepals. 




FIG. 97. The general features of the 
leaf, structure of the stem, flower, and 
seed of the Dicotyledons A, leaf; B, 
section of stem; 6 y , section of the flower 
(diagram); D, single flower; E, section of 
seed (after Gager, General Botany, pub- 
lished by P. Blakiston's Son and Co). 



ORDER RANALES, THE BUT- 
TERCUP ORDER 



The order Ranales as con- 
sidered here includes several 
families of both woody and herbaceous nature. The group con- 
tains many woody species, but there are also numerous species 
that are little or not at all frutescent. This situation has led 
certain authors to separate the woody forms from the herbaceous 
forms and to include the former in the order Magnoliales (Mag- 
nolia order), retaining the order Ranales for the herbaceous species 
alone. For our purpose we need not make this differentiation, 
but we may understand that the woody members are the more 
primitive and the herbaceous members are the later or derived 
types. 



SELECTED ORDERS AND FAMILIES OF DICOTYLEDONS 169 



The typical flower of the Randies is hypogynous and perfect, 
and commonly complete. The carpels are numerous and sep- 
arate or sometimes united, and in many forms they are arranged 
spirally over a more or less cone-shaped axis. The stamens are 
also numerous and typically arranged spirally below the carpels. 
Petals and sepals are separate, the petals sometimes lacking. 
The flowers are typically actinomorphic but certain forms such 
as larkspur, Delphinium, and monkshood, Aconitum, produce 
strikingly zygomorphic flowers. 

THE MAGNOLIA FAMILY 

The Magnoliaceae, or magnolia family (Fig. 98) are a group of 
about 10 genera and 70 or 80 species of trees and shrubs distrib- 
uted through the tropical and subtropical, but mostly temperate 
portions of eastern North 
America and Asia as far 
north as northeastern 
United States and northern 
Japan. 

Leaves commonly large, 
alternate, simple, often 
more or less leathery, often 
persistent; stipules large 
and foliacQOUS, deciduous; 
flowers hypogynous, large, 
often very showy, solitary, 
terminal or axillary, perfect 
and complete; sepals and 
petals numerous, often sim- 
ilar; stamens many, free, often spirally arranged in a beautiful 
series ; carpels many, free, arranged in close spirals over the elon- 
gated cone-like or spire-like axis, sometimes adherent in fruit; 
ovules 1 to 2 or more; fruit usually dry, a follicle or a samara, 
the group often more or less aggregated and completely covering 
the elongated cone-like axis; seeds large, with abundant, oily 
endosperm, often suspended from the cone on slender filaments. 

A noteworthy genus of the family is Magnolia, of which there 
are many important ornamental species such as the American, M. 
acuminata, and the old world M. soulangeana. The name 
Magnolia is derived from the name of a man, Pierre Magnol, a 
seventeenth century French botanist. Another member of the 




FIG. 98. Tho magnolia family, Magnoli- 
aceae. A, flowering twig of Magnolia grand i- 
flora; B, ripe fruit of same (after Mathewti); C, 
floral formula for the family. 



170 FLOWERS AND FLOWERING PLANTS 

group, Liriodendron tulipifera, the tulip tree of eastern United 
States, is an important species which furnishes an excellent 
commercial timber known as " white wood" or "yellow poplar." 
This species is also planted as an ornamental. The name, 
Liriodendron, comes from words meaning tree and lily, i.e., a tree 
bearing lilies. 

THE PAP AW FAMILY 

The Anofiaceae, commonly known as the papaw or custard 
apple family (Fig. 99) include woody plants of the nature of 
trees, shrubs or vines with aromatic wood. The family contains 
50 or more genera and several hundred species that are mostly 
tropical in both the eastern and western hemispheres, but there 

are a few species that are 
found in temperate climates, 
as in the American papaw. 

Leaves alternate, simple, 
entire, without stipules; flow- 
ers hypogynous, mostly per- 
fect, but sometimes imperfect; 
sepals commonly 3, separate 
or somewhat united; petals 
_ , , usually 6, often in two series: 

FIG. 99. The papaw family, Anonaceac. * 

A, papaw, Anona; B, floral diagram of Stamens many, Separate, Spl- 

Anona (after Baillon}; C, floral formula ra Uy arran g e d at the base of 
for the family. t , i . 

an elongated or congested axis ; 

carpels usually many, separate or sometimes united in the fleshy 
fruit, developing into an elongated, fleshy, aggregate fruit or a 
large berry, or in other cases becoming transformed into dry- 
fruits; seeds large, embryo very small; endosperm conspicuously 
wrinkled or ruminate. 

The family includes the North American Papaw, Asimina 
triloba, a low tree or bushy shrub growing as far north as New 
York, Michigan and Nebraska, noted for the large aromatic, 
juicy fruits that ripen in the autumn. These fruits are sometimes 
known as "poor man's bananas." The better known and more 
widely distributed forms are the numerous tropical species such as 
the "soursop" or "Juanabana," Anona muricata (Fig. 99), the 
"sweetsop," A. squamosa, and the " custard apple," A. reticulata, 
all of which produce large edible fruits. Soursop is widely 
planted, and the sap of the large fruit is used as a beverage and for 




SELECTED ORDERS AND FAMILIES OF DICOTYLEDONS 171 



the preparation of jellies, and the juicy pulp is used for conserves. 
The fruits of these plants are sometimes 6 or 8 inches long and 
about as broad, and more or less heart-shaped, the dark green 
surface being commonly roughened by the projection of the ends 
of the individual carpels. The seeds are imbedded in a copious 
white, fleshy or tallow-like pulp. 

THE NUTMEG FAMILY 

The Myristicaceae are commonly known as the nutmeg family 
(Fig. 100). The members of the family are largely tropical trees 
grouped in 8 or more genera and about 100 species. They are 
mostly evergreen broadleaf trees with wide distribution in the 
tropics where they are fre- 
quently seen in cultivation. 

Leaves alternate, simple, 
entire, commonly evergreen; 
flowers small, dioecious, acti- 
nomorphic, apetalous, in 
axillary clusters; calyx three- 
lobed, more or less globose or 
funnel-shaped ; stamens (in 
separate staminate flower) 2 
to 30, filaments united into a 
column (monadelphous), 
aborted ovary commonly 
present; pistil 1, superior, 

one-celled, ovule 1, style very short or none; fruit fleshy, 
dehiscing by two valves; seeds with a fleshy, laciniate aril; endo- 
sperm abundant, fatty, ruminate. 

The common nutmeg of commerce is Myristica fragrans (Fig. 
100), a tall tree with striking aroma that produces berry-like 
fruits 1.5 to 2.0 inches long. The fruit splits into two valves show- 
ing the scarlet aril surrounding the nutmeg which is enclosed in a 
hard shell. The aril becomes the mace of commerce, and the 
familiar spicy nutmegs are the firm seeds surrounded by the hard 
shell. The mace is used as a spice and the ground seed consti- 
tutes the popular aromatic flavoring material known as grated 
nutmeg. 

THE LAUREL FAMILY 

The laurels, Lauraceae, are mostly trees and shrubs but there 
are also a few parasitic herbaceous vines included in the family. 




FIG. 100. The nutmeg family, Myris- 
ticaceae. A, leaves and fruit of nutmeg, 
Myristica frayrans (after Baillori); B, sec- 
tion of fruit; C, floral formula for the 
family 



172 FLOWERS AND FLOWERING PLANTS 

There are about 40 genera and 1,000 species in the family and they 
are almost exclusively tropical in their distribution, but a few 
are known in subtropical and temperate climates. They are all 
very aromatic. 

The leaves are mostly alternate (rarely opposite) simple, 
leathery, and evergreen in tropical species, thin and deciduous 
in most temperate climate forms, aromatic; flowers apotalous, 
inconspicuous, yellow or green, actinomorphic, perfect, dioe- 
cious or polygamous; calyx six-parted; stamens in 3 to 4 whorls 
of three each, anthers opening by upwardly hinged flaps; ovary 
superior, one-celled, one-ovuled, style filiform or short; fruit a 
berry or drupe, indehiscent, edible in certain species; seed largo, 
without endosperm. 

The two best known members of the family in the United 
States are the native Sassafras, Sassafras, of the east and the 
California laurel, Umbellularia callfornicaj a spicy evergreen 
ornamental in that state. The spicebush, Benzoin aestivale, is a 
very aromatic native shrub of eastern United States where it is 
seen in woods and along streams. The bay tree of the florists, 
Laurus nobilis, has been popular for ornamental purposes because 
of the ease of pruning and clipping it into any desired form. The 
camphor tree, Camphora officinarum, also belongs in this family. 
It is an evergreen, broadleaved tree native to Japan and China, 
and planted in India, and is the most important natural source 
of camphor. Most natural camphor has been supplied by Japan, 
but this material is now manufactured in America. The cinna- 
mon bark of commerce is produced by Cinnamomum zeylanicum, 
a close relative of the camphor tree, cultivated in Ceylon. 

One of the most interesting genera of the Lauraceae is Persea, 
with 50 species native to the tropics and subtropics of both the 
old and new world. Some of them produce edible fruits, notably 
P. gratissima, commonly known as avocado or alligator pear. 
This species is grown widely in the tropics and in California for its 
popular edible fruits. The large, fleshy fruit (drupe) is more or 
less pear-shaped and contains a single, large, "stone" or "pit" 
imbedded in a thick layer of oily flesh. 

THE BARBERRY FAMILY 

The Berberidaceae, or barberry family (Fig. 101), includes some 
10 or more genera and 200 species of shrubs and herbs (some of 
them climbers) mainly distributed in the temperate portions of 



SELECTED ORDERS AND FAMILIES OF DICOTYLEDONS 173 

the northern hemisphere from Central Asia to India, and also 
along the Andes to the Straits of Magellan. Many of the 
species are beautiful and popular ornamentals. 

Leaves alternate, simple or compound; flowers solitary or in 
racemes or panicles, perfect, actinomorphic, hypogynous; sepals 
and petals usually 6, similar, commonly in two or more series; 
petals often nectariferous; stamens about as many as the petals 
and opposite them, sometimes sensitive, free, anthers opening by 
two valves hinged at the top; ovary superior, one-celled, with 




Kiu. 101 --The barbei ry family, Berberidacfae. A, flowering branch of bar- 
beiry, Berberis (after Le M, and Dec.); B, single flower of Berberis enlarged 
(after Baillon); C, floral diagram of Berberis (after Le M. and Dec,); /), floral 
diagram of Bcrbcrit* (after Baillon); E, floral formula for the family. 

few to many ovules; style short or none; fruit a berry or capsule; 
seeds with abundant endosperm. 

The barberries cultivated for landscape decoration in North 
America are mostly species of the large genus Berberis, of which 
there are several that are popular. The common barberry, B. 
vulgaris, and the Japanese barberry, B. thuribcrgii, are prized for 
the coloration of the foliage in autumn. The latter species also 
produces attractive scarlet berries in profusion. These plants 
are most commonly grown as a hedge. The common barberry 
is at present in bad repute in the northern wheat-producing area 
of the United States because of its relation to the propagation of 
wheat rust. An extensive eradication campaign directed toward 
this species has been under way for several years in thirteen 



174 



FLOWERS AND FLOWERING PLANTS 



northern wheat-growing states in the hope of lessening the losses 
due to that disease. 

The so-called ' 'Oregon grape," Mahonia aquifolium, is a 
member of this family. Among herbaceous species of the family 
we may mention the blue cohosh, Caulophyllum thalictroides, 
and the mandrake or may apple, Podophyllum peltatum. 

THE BUTTERCUP FAMILY 

The Ranunculaceae, commonly known as the buttercups or 
crowfoots (Fig. 102), include about 30 genera and 1,200 species 
of herbaceous perennials, including a few annuals and aquatic 




FIG. 102. The buttercup family, Ranunculaceae A, columbine, Aquileyia 
(after Mathews); B, marsh marigold, Caltha palustris (after Le M. and Dec.}; 
C, buttercup, Ranunculus (after Le M. and Dec.); D, vertical section of a flower 
of Ranunculus showing the floral axis (after Baillori); E, single flower of monks- 
hood, Aconitum (after Ba^llon); F, floral diagram of Ranunculus (after Le M. and 
Dec.); G, floral diagram of marsh marigold, Caltha, (after Le M. and Dec.); H, floral 
diagram of monkshood, Aconitum (after Baillon); /, floral diagram of columbine, 
Aquilegia (after Le M. and Dec.); J. floral formula for the family. 

species, and a few low shrubs and woody climbers, with a very 
wide distribution in the northern hemisphere. They are found 
in the Arctic region and at high altitudes in the mountains, 
but they are not so common in the tropics and in the southern 
hemisphere. Many highly prized ornamental species and varie- 
ties are included in the family. 

The leaves are alternate, the acaulescent species frequently 
with a broad group of radical leaves, but a few of the frutescent 



SELECTED ORDERS AND FAMILIES OF DICOTYLEDONS 175 

types (Clematis) with opposite leaves; flowers hypogynous, most 
commonly perfect and complete, but diclinous in a few forms, 
commonly actinomorphic, but zygomorphic in certain types 
such as larkspur (Delphinium) and monkshood (Aconitum); in 
Delphinium the petals are extended into conspicuous spurs, 
and in Aconitum an upper sepal is hooded and this covers a 
pair of narrow, elongated sepals; axis often cone-shaped or 
dome-shaped ; sepals 3 to many, separate, often brightly colored 
in apetalous forms; petals few to many, separate, often with 
nectaries, absent in numerous species; stamens many, free; 
carpels few to tnany, free or slightly united, one-celled, one- 
many-ovuled; fruit a cluster of achenes or follicles, sometimes 
berry-like, achenes often with persistent plumose style; seeds 
with very small embryo and abundant endosperm. 

There are many useful plants in this family. Among 
popular ornamentals may be mentioned the following: peony, 
Paeonia, columbine, Aquilegia (Fig. 102, A), larkspur, Delphinium, 
Virgin's bower, Clematis, marsh marigold, Caltha (Fig. 102, B), 
globe flower, Trollius and windflowers, Anemone. The state 
flower of Colorado is the blue columbine, Aquilegia cocrulca, and 
the South Dakota state flower is the Pasque flower, Pulsatilla 
hirsutissima, both of them members of this family. Medicinal 
plants in the group include aconite, Aconitum sp. (Fig. 102, E), 
snake root, Cimicifuga sp., and golden seal, Hydrastis. Certain 
species of Delphinium are poisonous to stock and they constitute 
a menace in certain western grazing grounds. 

The buttercup family has come to be regarded as a primitive 
group of herbaceous Dicotyledons and as closely related to the 
Magnoliaceae, and other low, woody Dicotyledons. The Mono- 
cotyledons are thought to have been derived from the dicoty- 
ledonous series from near these groups. The lowest Monocoty- 
ledons (Alismales) have much in common with buttercups and 
magnolias. 

THE WATERLILY FAMILY 

The waterlilies, Nymphaeaceae, are typically aquatic, perennial 
herbs with conspicuous floating leaves and large showy flowers of 
great ornamental value, mostly in the tropics and north temper- 
ate zone (Fig. 103). 

Leaves mostly floating, large and simple, on long petioles, 
arising from large horizontal rootstocks rooted in the mud at the 



176 



FLOWERS A ND FLOWERING PLANTS 



bottom of shallow lakes and ponds, or in some cases from floating 
stems, submerged leaves sometimes dissected (Cabomba); flowers 
usually solitary, large, showy, hypogynous, actinomorphic, 
perfect; sepals 3 to 4 to 6, or more; petals 3 or numerous, often 
showing gradual transitions between true petals and true stamens; 
stamens 3 to many; carpels 2 to 8 or more, commonly numerous, 
free or united into a many-celled ovary, as in Nuphar, or imbed- 
ded in the enlarged axis, as in Nelumbium; ovules one to many; 
fruit indehiscent, in Nelumbium the axis becomes greatly 
enlarged and contains many large, dry cavities in the upper 
surface, in each of which is one of the dry fruits* 




FIG. 103. The waterlily family, Nymphaeaceae. A, flower and leaf of lotus, 
Nelumbium (after Le M. and Dec.); B, fruiting receptacle of lotus, Nelumbium 
(after Le M. and Dec.); C, flower of waterlily, Nuphar (after Le M. and Dec.); 
D, floral diagram of Nuphar (after Le M. and Dec.); E, floral formula for the 
family. 



The family described above includes the common fishmoss, 
Cabomba, which is sometimes separated from this family and 
placed in a special family, Cabombaceae. This plant is in real- 
ity much more like the buttercups in flower structure than the 
commonly known waterlilies, but it is included here for conven- 
ience. It may be regarded as an intermediate type, at least. 

Conspicuous members of the Nymphaeceae are the yellow water- 
lilies, Nuphar, the white waterlilies, Nymphaea, the American 
lotus (Fig. 103, A and B), Nelumbium luteum, the Indian lotus, 
N. speciosum, and the watershield, Brasenia. Many tropical 
species have brilliantly colored flowers that are popular elements 
in aquatic gardening. One of the most interesting of all of the 
waterlilies is the great Victoria regia, a native of tropical South 



SELECTED ORDERS AND FAMILIES OF DICOTYLEDONS 177 

America, that produces very large flowers, and the broad, 
floating leaves with upturned edges are so large and firm as to 
support the weight of a small child. This plant was named for 
Queen Victoria of England. The name of the family is from 
Nymphae, the waternymphs. 



THE PEPPER FAMILY 

The pepper family (Fig. 104), Piperaceae, is included under the 
order Ranales as representative of a buttercup-like form that has 
become greatly reduced. They are mostly herbs or shrubs, 
but there are also a few trees and many woody climbers included 




FIG 104. The pepper family, Pipetaceae. A, leaves and clusters of fruits 
of peppei , Piper nigrum (after Baillon); B, floral formula for the family; (\ 
floral diagram of Piper (after Kail Ion) 

in the family. They are grouped in 10 to 12 genera and about 
1,200 species confined to the tropical and subtropical portions of 
the world. 

The leaves are large, alternate, opposite or whorled, and entire; 
flowers very small, actinomorphic, hypogynous, in dense catkin- 
like spikes or racemes; perianth 0; perfect or unisexual; stamens 
2 to 6 or more, free; ovary superior, one-celled, one-ovuled, 
stigmas 1 to 5, short; fruit berry-like with a fleshy, thin or dry 
pericarp; seeds small; endosperm abundant. 

The peppers are valuable mostly for the familiar black pepper, 
which is made from the dry fruits or ground dry fruits of Piper 
nigrum (Fig. 104), a woody vine of the East Indies. The inner 
stony portions of the dry fruits are powdered as "white pepper." 
The cubeb is another pepper, P. cubeba, and "betel" leaves, a 
favorite chewing material of the natives of India, are the leaves of 



178 FLOWERS AND FLOWERING PLANTS 

P. betle. There are probably about 700 species of Piper that 
have been described. The family also contains the ornamental 
genus Peperomia, of which there are more than 500 different 
species, some of which are grown for their foliage. 

These plants should not be confused with the "red peppers 77 
and chili peppers, " Jerusalem cherries/ 7 etc., of our gardens, 
which are mostly species of Capsicum, belonging to the potato 
family, Solanaceae. 



CHAPTER XIII 
THE MALLOWS AND GERANIUMS 

ORDER MALVALES, THE MALLOW ORDER 

The mallows, or Malvales, are regarded as among the early 
modifications of the buttercup type as included in the Randies. 
This relationship is clearly shown by their position on the 
chart. The close affiliation appears to be indicated by the many 
floral features which the two groups have in common. 

The mallow flower is typically actinomorphic, hypogynous, and 
polypetalous as in the buttercups, and often there are also many 
stamens and pistils, the latter varying from two to many, and 
being separate or more or less united. The stamens are indefinite 
in number, with their filaments united to form a continuous or 
broken sheath about the pistils. A tendency toward syncarpy 
and gamopetaly clearly indicates the more advanced nature of 
Malvales as compared with Ranales. The order is here expanded 
to include a number of apetalous forms that are distributed 
among different groups in other systems of classification. 

THE MALLOW FAMILY 

The Malvaceae, or mallow family, represent one of our most 
clearly marked families (Fig. 105) of herbs, shrubs, and trees of 
40 to 50 genera and nearly 1,000 species found practically 
throughout the world except in the colder regions. Members of 
the group may usually be identified by the five-merous flowers in 
which the numerous stamens are coherent by their filaments to 
form a sheathing tube enveloping the pistils. 

Leaves alternate, entire or variously lobed, often palmately 
veined or palmately lobed; flowers actinomorphic, hypogynous, 
usually perfect; sepals most commonly 5, sometimes more or less 
united and subtended by a group of calyx-like bracts (an invo- 
lucel); petals 5, free, but often joined to the stamen sheath or 
column at the base; stamens many, monadelphous, with free 
anthers clustered beneath the stigmas; carpels 5 to many, 
more or less united; ovules one to several in each carpel; styles 

179 



180 



FLOWERS AND FLOWERING PLANTS 



commonly as many as carpels; fruit typically dry, capsuiar or 
rarely berry-like, breaking into subdivisions as it ripens; seed 
with little or no endosperm. 

The mallow family includes many very valuable economic 
plants. Among these may be mentioned cotton (Fig. 105, F), 
Gossypium arboreum, G. brasiliense, G. herbaceum, G. hirsutwn, 
and other species that are grown for the hairy covering of the 
seeds which constitutes the " cotton-wool" or " cotton" of 
commerce. This cotton is used extensively for the manufacture 
of thread and cloth. Cotton treated with a strong alkali is 
made stronger and more or less silky and is known as "mercer- 




FIG. 105. The mallow family, Malvaceae. A, leaves arid fioweis of lose 
mallow, Hibiscus (after Baillon); B, vertical section of a flower of mallow, Maloa 
(after Baillon); C, floral diagram of Malva (after Le M. and Dec.); D, floral 
formula for the family; E, fruit of Malva (after Baillon); F, leaves arid flowers 
of cotton, Gossypium (after Kobbins). 

ized" cotton, after Mercer, the discoverer of the method. 
Besides cotton in one or another of the usual senses, the plant 
furnishes many other products such as cottonseed oil, meal, etc. 
Guncotton, a powerful explosive, is made by treating the cotton 
lint with nitric and sulphuric acids and by various subsequent 
transformations. 

There are also many ornamental species in the family especially 
in the genera Hibiscus, Althaea, Callirrhoe, etc. There are about 
200 species of Hibiscus, many of which are highly prized on 
account of their large, showy flowers. One of the species, H. 
esculentus, furnishes the sections of gelatinous, green capsules 



THE MALLOWS AND GERANIUMS 



181 



known as "okra" or " gumbo " used in soups. The common 
hollyhock is Althaea rosea, which is a familiar garden plant, 
with its large flowers of many colors and its double-flowered 
varieties. 

THE LINDEN FAMILY 

The Tiliaceae, or linden family (Fig. 106) comprise 35 genera 
and about 375 species of trees and shrubs that are very widely 
distributed in the tropics and warmer portions of the world 
with a number of species also characteristic of temperate cli- 
mates. Lindens are also known as basswoods and lime trees 
in certain countries. 




Fro. 100 The linden family, Tiliaceae. A, leaves and flowers of linden, 
Tilia (after Le M. and Dec.); B, floral formula for the family; C, floral diagram 
of Tilia (after Le M. and Dec.). 

Inner bark very fibrous; leaves alternate, simple, entire, 
dentate or lobed, often oblique at the base (Tilia) \ flowers 
actinomorphic, hypogynous, usually perfect; sepals usually 5, 
separate or slightly united; petals 5 or more, often glandular at 
the base; stamens numerous, free or slightly united at the base 
into a number of bundles; ovary superior, two- to ten-celled, 
with one to many ovules in each cell ; fruit two- to ten-celled or 
one-celled by abortion of the other cells, capsule, berry-like or 
drupaceous, dehiscent or indehiscent; seed one to many in each 
cell; endosperm abundant or none. 

The lindens are commonly regarded with great favor as orna- 
mental trees. The American linden or basswood, Tilia americana, 
and the European linden, T. europaea, are included among the 



182 FLOWERS AND FLOWERING PLANTS 

highly prized ornamental trees in the climates to which they are 
adapted. There are many forms and cultivated varieties of 
both of these species. The American linden also produces a 
light, soft, even-grained, tough wood which is much used for 
veneer backing, cooperage, excelsior, apiarist's supplies, and 
general woodenware. This is one of the most important com- 
mercial woods of the United States. 

THE CACAO FAMILY 

This is the Sterculiaceae, a family of trees and shrubs (Fig. 107) 
with soft wood (few herbs) of some 50 genera and 750 species, 
largely confined to the tropics and subtropics. 




BAG 



FIG. 107. The cacao family, Stercuhaceae. A, leaves, flowers, and funt 
of chocolate, Theobroma cacao (after Baillori); B, floral diagram of Theobroma 
(after Baillon); C, floral formula for the family. 

The leaves are alternate, simple, or digitately compound; 
flowers resembling those in Malvaceae, perfect or diclinous, 
hypogynous, actinomorphic ; sepals 3 to 5, somewhat united; 
petals 5 or none; stamens numerous, more or less connate into a 
tube; ovary superior, of 2 to 5 or 10 more or less united car- 
pels; style simple, or divided into lobes or free from the base; 
fruit dry or rarely berry-like', usually dehiscent; seeds with or 
without endosperm. 

One of the most interesting and commercially important 
members of this family is the chocolate plant (Fig. 107), Theo- 
broma cacao, a small tree native to Central and South America, 
and now grown as a cultivated plant in the tropical portions of 
both hemispheres. The fruits in this species are large woody 
drupes or dry pods containing numerous large oily seeds imbedded 
in the pulp of the interior. Chocolate and cocoa of commerce 
are prepared by grinding the roasted seeds of this plant and then 



THE MALLOWS AND GERANIUMS 



183 



adding sugar, vanilla, and other substances to give them 
their characteristic properties. A very oily product known as 
"cacao butter" is also prepared from the seeds. This is quite 
different from the important fats secured from the coconut 
seed. The cola nuts of commerce are produced by the cola 
tree, Cola acuminata, and from these certain alkaloidal drugs 
are prepared. The inner bark of certain other species furnish 
tough fibers that are used for heavy mats and cordage and 
even for paper. 

THE ELM FAMILY 

The Ulmaceae, commonly known as the elm family (Fig. 108), 
are comprised of 12 to 13 genera and about 140 species of decidu- 
ous trees and shrubs, widely distributed in the north temperate 




FIG. 108. The elm family, Ulmaceae. A, leaf of American elm, Ulmus amen- 
cana; B, flower cluster of same; (7, and D, flowers of same; E, flower cluster of red 
elm, Ulmus fulva; F, flower of same; (?, fruits of Ulmus amcricana; H, fruits of 
Ulmus fulva\ I, floral formula for the family (after Mathews). 

zone, with a few species reaching into the tropics. There are 
several important ornamental and timber-producing species in 
the family. 

Leaves alternate, simple, pinnately veined, often very unsym- 
metrical at the base, and coarsely toothed ; flowers small, in fascicles 
from buds on one-year-old twigs, perfect, polygamous or monoe- 
cious, the pistillate sometimes solitary; apetalous; sepals 4 to 8, 
united to form a more or less campanulate calyx; stamens same 
number as calyx lobes or more, inserted at the base of the calyx; 
ovary superior, composed of 2 carpels, but usually one-celled, 
one-ovuled; styles 2; fruit a flat, membranous samara, a nut, or 



184 FLOWERS AND FLOWERING PLANTS 

drupe; seed without endosperm. The flowers are produced long 
before the leaves appear in many species of elm. 

The two best-known members of this family are the American 
elm, Ulmus americana, and the English elm, U. campestris, 
both of which are planted for shade and landscape purposes in 
many parts of the world. The former is also a very important 
timber tree in the United States, the wood being very tough 
and strong and used for the cheaper grades of furniture. The 
slippery elm, U. fulva, is noted for the gelatinous inner bark 
which possesses medicinal properties. A noteworthy old world 
elm is the camperdown elm, U. scabra, which has pendulous 
branches that form a rounded or very widely spreading crown. 
The hackberry, Celtis, is a tree that resembles the elm somewhat 
but the fruit is a drupe rather than a samara. It is a valuable 
tree for ornamental purposes in arid and semiarid localities 
where the elms do not thrive. 

THE MULBERRY FAMILY 

The Moraceae, or mulberry family (Fig. 109), comprise about 
55 genera and nearly 1,000 species of trees, shrubs, herbs, and 
vines with milky juice, that are largely tropical in distribution, 
but there are also numerous species in the temperate portions of 
the world^ 

Leaves alternate, usually simple, often deeply lobed; flowers 
small and much reduced, often produced in dense heads or hol- 
low receptacles, monoecious or dioecious, actinomorphic ; sepals 
commonly 4, more or less united, sometimes lacking; petals 0; 
stamens equal in number to calyx lobes; ovary usually superior, 
one- to two-celled, one- to two-ovuled, stigmas 1 to 2, filiform; 
fruit an achene, drupe, or nut, sometimes the true fruits are 
enveloped by or imbedded in a thickened, fleshy perianth as in 
the mulberry, or in a greatly enlarged axis as in the fig. 

The mulberry is some species of Morus, the two common 
species being the white mulberry, M. alba, and the black mul- 
berry, M. nigra. The Russian mulberry is a variety of the 
white mulberry, and there are numerous other varieties of 
that species that are useful as ornamentals and for silkworm feed- 
ing. The fruit in the mulberry is a ripened pistillate inflorescence 
in which the individual fleshy segments are formed largely from 
the enlarged sepals which come to cover the ripened ovary. The 
breadfruit of the South Seas and Asiatic Tropics is Artocarpu* 



THE MALLOWS AND GERANIUMS 



185 



communtSj in which the fruit is much the same as a mulberry 
morphologically, but it may be 4 to 8 inches long, and is usually 
eaten cooked rather than as a fresh fruit. The so-called paper 
mulberry, Broussonetia papyrifera, of the Far East, is used in 
paper manufacture. 

Other interesting members of the mulberry family are the 
Osage orange, Toxylon pomiferum, of the United States, noted for 
its extremely hard wood, and its large orange-like fruits, and figs, 
Ficus, which are largely tropical in their distribution. Nearly 
800 different species of figs have been described and they vary from 




FIG. 109.-- The mulberry family, Moraceae, and hemp family, Cannabinaceai, 
A, flowering stem of hop, Humulus lupulus (after Bentham), B, details of flower 
and fruit of same; (7, leaves and flower clusters (figs) of fig, Ficus (after Baillon); 
D, single female flower from the interior of one of the inflorescences or figs 
(after Baillon); E, floral formula for the Urticaceae. 

giant trees to erect shrubs and climbing vines, some of which are 
grown for fruit and others for ornamental purposes. The edible 
figs are mostly produced by varieties of F. carica. The fig 
fruit is in reality the hollow and greatly enlarged fleshy receptacle 
bearing the hundreds of flowers that are thickly clustered on the 
inner surface. Figs have been grown successfully and on an 
increasingly important commercial scale in California for about 
25 years. The common " rubber plant " of our conservatories is 
a fig, F. elastica, as is the banyan tree of India, F. benghalensis. 
Hemp, Cannabis, and hops, Humulus, of the Cannabinaceae are 
closely related to the mulberry. 



186 



FLOWERS AND FLOWERING PLANTS 



THE NETTLE FAMILY 

The Urticaceae include herbs or undershrubs and sometimes 
vines grouped into about 40 genera and 500 species with a very- 
wide distribution, but more abundantly represented in the 
tropics. The stems and leaves are often armed with stinging 
epidermal hairs (Fig. 110). 

Leaves alternate or opposite, simple; flowers very small and 
inconspicuous, usually unisexual, variously borne in cymes ; calyx 
mostly four-parted or four- to five-lobed ; petals ; stamens of the 




O s CoS 45 P ! 
PrUAcHDR 

D 

Fia. 110. The nettle family, Urticaceae. A, floweiing branch of nettle, 
Urtica dioica; B, single stammate flower, C, single pistillate flower; D, floral 
formula for the family (after Mathews). 

same number as sepals; ovary solitary, one-celled, one-seeded, 
free or more or less attached to the calyx; style simple; fruit an 
achene, or becoming drupaceous on account of the enlarged and 
succulent calyx which invests the ripened ovary in certain forms; 
seed with endosperm. 

The most of the species of nettles are noxious weeds. A few 
have a limited value as ornamentals. The ramie or Chinese silk 
plant, Boehmeria nivea, is an important fiber plant in China and 
Japan, and the plant has some ornamental value. 

ORDER GERANIALES, THE GERANIUM ORDER 
The Geraniums and their kin, the Geraniales, constitute a large 
order of diversified families of shrubs and herbs which reveal 



THE MALLOWS AND GERANIUMS 



187 



certain features that are more or less similar to those that 
characterize the mallows. The order is regarded as another 
early modification of the buttercup type that has developed 
more or less parallel with the Malvales. The greater degree of 
syncarpy, together with the reduction in the number of carpels 
and stamens and a decided tendency toward a standardization in 
the number of these structures mark the Geraniales as a group 
to be considered somewhat more advanced than the Malvales. 

The geranium flower is typically hypogynous, perfect and 
actinomorphic, but with a tendency toward zygomorphy; sepals 
and petals 5; stamens 5 to 10; carpels 5, united. The order as 
here treated also includes certain apetalous families of more or 
less uncertain affiliations. 

THE GERANIUM FAMILY 

The Geraniaceae, include the true geraniums (Fig. Ill) and 
their more immediate kin. They are largely annual or perennial 




CAP BEAKED 
c 

Fio. 111. The geranium family, Geraniaceae. A, flowering habit of wild 
geranium, Geranium maculatum; B, three stages in the ripening joi the fruit 
of geranium; C, floral formula for the family; D, floral diagram for the family, 
or for geranium (after Mathews). 

herbs or undershrubs, or rarely arborescent, with a wide distribu- 
tion in the north temperate zone and in the subtropics, with a 
peculiar, concentration in South Africa. The family includes 11 
genera and about 650 species. 

Leaves alternate or opposite, lobed, simple, dissected, or com- 
pound; flowers commonly conspicuous, perfect, and usually regular 
or somewhat zygomorphic; sepals 5, separate or united somewhat 
in certain species, the dorsal sepals sometimes spurred; petals 5 



188 FLOWERS AND FLOWERING PLANTS 

or 0; stamens 2 to 3 times the number of petals, but usually 10 or 
5, some of them sterile, more or less connate at base ; pistil three- 
to five-lobed, commonly of 5 carpels, each prolonged into a 
style; ovules 1 in each carpel; fruit lobed, dry, one-seeded in 
each carpel, carpels commonly separating in fruit; seed with 
little endosperm. 

The geraniums are of value principally on account of their 
beautiful fragrant flowers and the aromatic nature of their 
leaves. Scores of species are grown in cultivation as house 
plants and for flower-bed decoration out of doors. The common- 
est so-called "geranium" in cultivation is not a Geranium but a 
species of Pelargonium, a closely related genus of 250 or more 
species, native of South Africa. 

THE OXALIS FAMILY 

The Oxalidaceae, include the "sorrels" or oxalises; they are 
herbaceous or somewhat woody plants closely related to the 




FIG. 112. The oxalis family, Oxalidaceae. A, leaves and flowers of sorrel, 
Oxahs montana; B, single petal; (', and D, stamens (after Mathews); E, floral 
diagram (after Le M. and Dec.); F, floral formula for the family. 

geraniums (Fig. 112). There are 10 or more genera and several 
hundred species in the tropics and subtropics, and they, like the 
geraniums, are particularly abundant in South Africa. An 
abundance of oxalic acid in the juice of many species has given 
rise to the popular name "sheep sour," etc. The presence of 
this material is also reflected in the technical name, Oxalis, 
which is Greek for sour. 

Leaves alternate, digitately or palmately compound, often tri- 
foliate; flowers perfect, hypogynous, and regular; sepals and 
petals 5, more or less united at the base in certain species; 
stamens 10, more or less connate at base, sometimes 5 of them 
lack anthers; ovary five-celled, superior, two- to many-ovuled, 



THE M ALLOWS AND GERANIUMS 



189 



styles 5; fruit typically a capsule with many seeds, sometimes 
berry-like ; seeds with elastic coat that serves to propel them from 
the fruit; endosperm abundant. The fruit is one of the most 
striking differences between the Oxalidaceae and the Geraniaceae. 
Various species and varieties of Oxalis are prized as house 
plants and potted herbs because of their large, brilliant, yellow or 
purple flowers, and curious sensitive leaves. The carambola, 
Averrhoa carambola, is an evergreen tree of tropical India and 
China that produces a juicy, fragrant, acid or sweet fruit used 
as a vegetable and as a dessert. 

THE FLAX FAMILY 

The flax family, fynaceae, is another natural group (Fig. 113) 
with strong resemblances to the Geraniaceae. The family 




FICJ. 113.- The flax family, Linaceae. A, flowering habit of flax, Linarn 
(after Le M. and Dec.}; B, floral diagram oiLinum (after Le M. and Dec.}; C, floral 
formula for tho family; D, flowering stem and flower details of commercial flax, 
Linum usitatissimum (after Bentham). 

includes 12 to 14 genera and about 150 species of herbs or shrubs 
of wide distribution in temperate regions. 

Leaves simple, alternate or opposite; flowers perfect, actino- 
morphic, hypogynous; sepals usually 5, free or united at the 
base, persistent; petals usually 5, free, fugacious, often clawed; 
stamens 5, sometimes with other small filaments without anthers 
(staminodes), filaments connate at base; ovary superior, carpels 
2 to 5, or sometimes apparently 4 to 10 by the formation of 
false radial partitions through the carpels ; styles same number as 
carpels; fruit usually a several-seeded capsule ; seeds flat, shining; 
endosperm abundant or 0. 



190 FLOWERS AND FLOWERING PLANTS 

This is a very important family from the standpoint of the 
utilitarian values of its products. Flax has been cultivated for 
its fiber since prehistoric ages. The ancient Egyptians and 
Hebrews used linen cloth made from flax 3,000 years B. C. 
Several species of wild flax are known in North America, among 
them are the forms with yellow flowers of our prairies and the 
forms with blue flowers of the roadsides and fields. Many 
species and varieties are grown for fibers and seeds in different 
parts of the world. A species with blue flowers, Linum perenne, 
and another with red flowers, L. grandiflorum, are sometimes 
grown for ornamental purposes. Various useful products such as 
linseed oil, are manufactured from the seeds of the flax plants. 
United States grows flax largely for the seed, Russia grows it 
mostly for the fiber. 

THE ORANGE FAMILY 

The Rutaceae, commonly known as the rue or orange family 
(Fig. 114), comprise an important group of about 100 genera and 
1,000 species of trees and shrubs of temperate and tropical 
climates in both the Old and New World. They are numerous in 
Australia and South Africa. 

Leaves alternate or opposite, simple or compound, glandular, 
aromatic, often evergreen; flowers perfect, rarely polygamo- 
dicecious, regular, sometimes zygomorphic; sepals 3 to 5, free 
or slightly united; petals 3 to 5, free; stamens of same number or 
more than twice the number of petals, attached to a disk, free 
or rarely united; carpels 2 to 5, usually united to form a superior, 
four- to five-celled ovary, sometimes free ; styles connate ; ovules 
one to many in each carpel; fruit berry-like, drupaceous, or 
leathery and dry, aromatic, large and heavy in Citrus; seeds 
many, often with more than one embryo; endosperm fleshy or 0. 

The most important member of the rue family from the eco- 
nomic viewpoint is the genus Citrus which furnishes the various 
types of " citrus fruits," including oranges, lemons, limes, tanger- 
ines, and grapefruits. The genus is mainly confined naturally 
to the Old World where the species grow in abundance in Asia 
and Malaysia, but they are also cultivated extensively in many 
other parts of the world as in Africa, Spain, Florida, Texas, 
and California, for their edible fruits and for ornament as well. 
Some of the more important economic species are as follows: 



THE MALLOWS AND GERANIUMS 



191 



sweet orange, C. sinensis, sour orange, (7. aurantium, king orange, 
C. nobilis, with its variety deliciosa, the tangerine, citron, C. 
medica, grapefruit, C. grandis, lemon, C. limonia, and lime, C. 
aurantifolia. The trifoliate orange, C. trifoliata, is grown for 
ornamental purposes and as budding stock for edible forms. 




FIG. 114. The orange family, Rutaceae. A, flowering twig of sour orange, 
Citrus; B, vertical section of a flower of the same; C, section of the fruit of same; 
D, a seed (all after Robbins); E, floral diagram for Citrus (after Le M. and Dec.); 
f\ floral diagram of rue, Ruta (after Le M. and Dec.); G, floral formula for the 
family. 

Bergamot oil is prepared chiefly from C. bergamia, a small tree 
cultivated in southern Europe. The navel orange or "seedless 
orange " is a mutant found many years ago in Brazil, and since 
has been improved and grown successfully on a large scale in 
California. A certain variety of grapefruit is also known which 
is ordinarily seedless. 

THE BALSAM FAMILY 

The Balsaminaceae are known commonly as the touch-me-not 
family (Fig. 115) as well as the balsam family. They are largely 
succulent herbs of wide distribution but are more prominent in 
tropical Asia and Africa. There are two or more genera and 
about 500 species in the family. 

Leaves alternate or opposite, simple; flowers perfect, hypo- 
gynous, zygomorphic, brightly colored, solitary or somewhat 
umbellately clustered; sepals 3, rarely 5, unequal, the 2 lateral 
ones small and greenish, the posterior one prolonged backward 
into a nectariferous, tubular spur, petals 5, or 3 by the union 
of two pairs, unequal ; stamens 5, filaments short and broad, 



192 



FLOWERS AND FLOWERING PLANTS 



anthers connate around the ovary; ovary superior, five-celled, 
with few to many ovules in each cell ; fruit a succulent capsule 
or berry, with several seeds ; endosperm 0. 

These plants are called ' 'touch-me-nots" because of the sudden 
elastic and vigorous splitting of the succulent capsule into twisted 
segments and the consequent scattering of the seeds. This 
peculiar type of dehiscence may be unusually impressive if the 
ripening fruit is lightly pinched at just the proper moment. 
This condition is reflected in the name Impatiens for the common 
balsam. 




FIG. 115. The balsam family, Balsaminaceae. A, flowering twig of jewel- 
weed, Impatiens fulva; B, section of a flower; C, ripening fruits (after Mathews); 
D, floral formula for the family; E, floral diagram of touch-me-not, fmpatiens 
noli-me-tangere (after Le M. and Dec.). 

There are several species and varieties of Impatiens, the common 
genus, grown in cultivation, among which is the garden balsam, 7. 
balsamina, and the Sultan's balsam, /. sultani, named after the 
Sultan of Zanzibar, in whose country the plant is indigenous. 

THE SPURGE FAMILY 

The Euphorbiaceae are a family (Fig. 116) composed of about 
250 genera and more than 4,000 species of herbs, shrubs, and trees 
with milky juice, very widely distributed throughout the world, 
being very common in the tropics and temperate zones of both 
hemispheres. Some of them are succulent and thorny and more 
or less cactus-like. 

Leaves alternate, rarely opposite, simple, deeply lobed or com- 
pound, sometimes much reduced ; monoecious or dioecious, flowers 



THE MALLOWS AND GERANIUMS 



193 



actinomorphic, hypogynous; sepals various, sometimes ; petals 
commonly 0; stamens one to many (sometimes 1,000), free or 
united ; ovary superior, usually three-celled, with 1 or 2 ovules in 
each cell ; fruit a capsule or drupe ; seeds often with a conspicuous 
caruncle ; endosperm abundant. Sometimes the naked pistillate 
flowers are surrounded by numerous staminate flowers and 
sterile stamens and the whole group then surrounded by 
a corolla-like involucre, the structure as a whole being known 
as a "cyathium." The uppermost leaves, surrounding the 




FIG. 116. The spurge family, Euphorbiaceae. A, flowering branch of rubber- 
plant, Hevea guyanensis; B, cluster of flowers; C, a single male flower; D, a female 
flower with calyx removed, E, floweiing stem of snow-on-the-mouiitains, Eu- 
phorbia maiginata, F, fruit (all from Sargent}. 

flowers, in a number of species are brightly colored and those 
structures are popularly known as flowers. 

The spurge family includes many plants of great interest and 
economic value. Many of them are highly prized as pot herbs 
and ornamentals, among which are the magnificent Christmas 
Poinsettia, Poinsettia pulcherrima, scarlet plume, Euphorbia 
jacquinae flora, crown-of-thorns, E. splendens, a very spiny plant, 
and the Mexican fire plant, P. heterophylla. Certain species 
and numerous varieties of Codiaeum, known as "crotons," 
are popular as foliage plants. The leaves of Codiaeum are slender, 
as a rule, and are marked with yellow, red, and white mottling or 
variegation. 

The castor-oil plant is also grown for ornamental purposes. 
This is Ricinus communis, the seeds of which furnish the castor 



194 FLOWERS AND FLOWERING PLANTS 

oil of commerce. Hundreds of different forms of this plant are 
recognized. The oil is used in medicine, as a lubricant for ma- 
chinery, and it has been used also as an illuminating oil. 

Crude rubber or caoutchouc is secured from several different 
species in this family. The more important rubber plants of the 
family are Hevea brasiliensis and H. guyanensis of South America. 
Certain species of Manihot, of Brazil, also yield crude rubber, 
and one of these, M. utilissima, is the cassava or tapioca plant 
from the roots of which tapioca and farina are prepared. 



CHAPTER XIV 
THE TEAS, POPPIES, AND PINKS 

ORDER THEALES, THE TEA ORDER 

This group may be known as the tea order, since the teas in the 
common commercial sense are included as one of the families of 
the order. They are mostly trees and shrubs or woody climbers 
but the order also includes a number of herbaceous species. The 
treatment of the order here is somewhat broader than that in 
certain other systems, and so one will find some of the following 
families treated under separate orders by other authors. The 
teas include another prominent group of families that became 
differentiated from the Ranales at a rather early time. 

The flowers are typically hypogynous but with a tendency 
toward perigyny, mostly perfect and regular, but with a strong 
tendency toward zygomorphy in certain families; sepals and 
petals present, free; stamens few or many, free or somewhat con- 
nate; ovary superior, compound, of two to more carpels, two to 
several ovuled, with axilo or parietal placentation. 

THE TEA FAMILY 

The Theaceae, commonly known as the tea family (Fig. 117), 
include 16 genera and about 175 species of trees and shrubs 
of the tropics and warmer temperate portions of East Asia. 

Leaves alternate, simple, usually evergreen; flowers commonly 
solitary or occasionally racemose or paniculate, often large and 
showy, hypogynous, regular, perfect, rarely diclinous; sepals 5, 
free or slightly united, imbricated; petals 5, free or slightly united; 
stamens numerous, in several series, the outer more or less united 
into a tube, free or adnate to the base of the petals; ovary 
superior, three- to five-celled, styles 3 to 5, free or connate below; 
ovules 2 or more in each cell; fruit a woody capsule or drupaceous; 
endosperm scanty. 

The tea of commerce is the dried leaves of some species of 
Thea, especially T. sinensis (or Camellia thed), or some of its 

195 



196 



FLOWERS AND FLOWERING PLANTS 



many cultivated varieties. The camellias are noteworthy on 
account of their large, showy, white or purplish flowers and beau- 
tiful foliage. They are commonly grown for ornamental purposes 
in warm climates, as in southern United States. 




FIG. 117.- The tea family, Theaceae. A, flowering twigs of tea, Then (after 
Baillori); B, single flower of Thea (after Baillori); C, floral diagtam of Thea (aftm 
Baillori), D, floral formula for the family. 

THE GARCINIA FAMILY 

This family, Guttiferaceae, is also known as the St. John's 
wort family. They are trees, shrubs and a few herbs to the 
number of about 45 genera and 700 species that are largely 
tropical in distribution. The juice is often yellowish or green 
and resinous. 

Leaves opposite, pinnately veined, simple, entire; flowers 
hypogynous, actinomorphic, perfect or mostly polygamo- 
dicecious, solitary or cyrnose; sepals and petals 2 to 6; stamens 
numerous, free or connate below into several bundles; dwarf 
ovary commonly present in male flowers, and staminodes usually 
present in female flowers; ovary superior, two- to many-celled, 
ovules one to many in each cell; stigmatic lobes often heavy 
and radiate; fruit fleshy or coriaceous, berry-like or drupaceous; 
seeds without endosperm; embryo large. 

The mangosteen, Garcinia mangostana, a small tree of the 
Malay region, producing orange-like fruits, belongs to this 
family. Garcinia is from Garcin, a French botanist of the fore 
part of the eighteenth century. The St. John's wort, or the 
genus Hypericum, of about 200 species, is commonly represented 
in the flora of temperate climates. Some of these are culti- 
vated for their large and beautiful, waxy, yellow flowers. 



THE TEAS, POPPIES, AND PINKS 



THE VIOLET FAMILY 



197 



The violet family, Violaceae, is probably one of the best known 
and most popular of all dicotyledonous groups (Fig. 118). These 
are largely herbs, but there are also a number of shrubs and even 
a few trees included in the family along with the modest violet. 
About 400 species in 15 genera have been described and these 
have a very wide distribution in temperate and tropical regions. 

Leaves all basal or alternate, rarely opposite, simple, sometimes 
deeply lobed; flowers hypogynous, irregular or regular, usually 
perfect, sometimes cleistogamous ; sepals 5, free or somewhat 
connate to form a ring about the ovary; petals 5, unequal, the 




FIG 118 -Tho violet family, Violaceae. A, a species of violet, Viola (after 
floi'/on); B, mteinal structure of flower in. Viola (after Baillori); C, floral diagram 
of Viola (after Baillon); D, floral formula for the family. 

lowest one often larger and saccate or spurred; stamens 5, 
joined in a ring around the ovary, some of them irregular in 
form; ovary free, one-celled, but often with 3 (or 4 to 5) parietal 
placentae, style simple, rarely divided, ovules numerous; fruit an 
elastically opening capsule, or berry-like; endosperm abundant. 

The violets and pansies, which are also violets, are among the 
most popular garden flowers, and some of them are grown by 
the florists in greenhouses to supply the winter trade of northern 
countries. The common cultivated violet is Viola odorata, and 
the pansy is V. tricolor , both of whieh have given rise to many 
varieties in cultivation. 

The cleistogamous flowers of violets are of peculiar interest 
because they are borne on short pedicels or runners more or less 
underneath the rest of the plant and they have no petals, but 
they bear an abundance of seeds in species in whioh the normar 
flowers are sterile. 



198 FLOWERS AND FLOWERING PLANTS 

THE PASSION FLOWER FAMILY 

The passion flowers, Passifloraceae, are usually tendril-climbing 
herbs or woody plants of about 18 genera and 350 species of the 
tropics and subtropics; abundant in South America. They 
are called " passion flowers" because of a fancied resemblance of 
the flower parts to the implements of the crucifixion. 

Leaves alternate, simple, entire or lobed; tendrils axillary, 
simple; flowers perfect or rarely diclinous, actinomorphic, 
perigynous; sepals 3 to 5, imbricated, free, persistent, often 
colored; petals 3 to 5, sometimes wanting, inserted on the rim 
of the calyx, free, sometimes fringed; a corona, made up of one or 
more rows of slender filaments or scales, formed by a radial out- 
growth of the axis usually is present; stamens 5 or more, free or 
united in bundles ; ovary superior, sometimes borne on an elonga- 
tion of the stalk within the calyx (gynophore), one-celled, with 3 
to 5 parietal placentae; ovules numerous; styles 1 to 5, free or stig- 
mas often united ; fruit a capsule or berry ; seeds with a pitted coat 
and inclosed by a pulpy aril; endosperm fleshy; embryo large. 

The giant granadilla, Passi flora quadrangularis, a tropical 
climber with four-angled and four-winged sterns and very large 
edible fruits, belongs here. Several species are grown for their 
large and odd flowers. 

THE PAPAYA FAMILY 

The Caricaceae, the papayas, also commonly known a papaws, 
includes a few species that are mostly succulent-stemmed, 
tropical trees with soft wood and milky juice. The 30 or more 
species are mostly confined to the tropics and subtropics of the 
western hemisphere, but the common papaya, Carica papaya, is 
widely grown for its edible fruits. 

The stems are straight, unbranched, and palm-like and they 
bear a terminal crown of large palmately lobed leaves; flowers 
hypogynous, commonly dioecious, sometimes perfect, in few- 
flowered racemes; calyx very inconspicuous, five-lobed; petals 5 
in the male flowers, united to form a slender tube, nearly separate 
in female flowers ; stamens 10, inserted in two sets on the corolla ; 
filaments short; ovary superior, sessile, one-celled, with many 
ovules on five parietal placentae; style short, or stigma sessile; 
fruit a large, pulpy berry with many seeds; endosperm fleshy. 

The fruit of the papaya is oblong or nearly spherical, yellow or 
orange and varies from 3 to 20 inches long, with a thick wall of 



THE TEAS, POPPIES, AND PINKS 199 

fleshy tissue inclosing an angled cavity with many dark seeds 
scattered over the wall. It is often eaten as a vegetable and the 
milky juice from the fruit when dried and powdered becomes the 
papain of commerce. This papaw must not be confused with 
the North American papaw, Asimina triloba, which belongs to 
the Anonaceae, as indicated in an earlier chapter. 

ORDER PAPAVERALES, THE POPPY ORDER 

This group is known as the poppies and their kin. They are 
largely herbaceous, but numerous shrubs and a few trees are also 
included in some of the families that are represented in the trop- 
ics. The order as here treated is represented by a number of fam- 
ilies that are sometimes broken up into a number of orders, as in 
the new system proposed by Hutchinson. The broader, more 
general treatment will serve our purpose much better. The fam- 
ilies commonly included in this series show unmistakable relation- 
ships with the Ranales. They evidently represent another line of 
development more or less parallel with the ThealeSj Malvales, 
and Geraniales, all of which have arisen from the Ranales. 

The flowers are hypogynous or somewhat porigynous, actino- 
morphic, with a tendency toward zygomorphy, perfect; sepals 
and petals present; stamens many to few, free or more or less 
united into bundles; carpels many to few, syncarpous; ovules 
many to few; placentation mostly parietal. 

THE POPPY FAMILY 

The poppies, Papaveraceae (Fig. 119), are mostly annual or per- 
ennial, milky-juiced herbs included in 25 genera and about 150 
species of wide distribution, but more abundant in the north tem- 
perate portions of both hemispheres. The milky juice (latex) is 
sometimes brightly colored. 

Leaves alternate or the upper ones sometimes whorled, simple, 
entire, lobed or deeply divided ; flowers usually solitary, hypogy- 
nous, often large and showy, actinomorphic, perfect; sepals 
typically 2, sometimes 3, caducous; petals 4 to 6 or many, free, 
falling early, often crumpled; stamens many, free, in whorls, fila- 
ments slender; ovary superior, of two to many united carpels, 
usually one-celled, with parietal placentae, or many-celled, carpels 
separating in fruit in some species, style short or 0, stigma often 
broad; fruit a many-seeded capsule opening by pores or valves; 
seeds numerous; embryo very small; endosperm abundant. 



200 



FLOWERS AND FLOWERING PLANTS 



There are many very popular garden flowers in this family, 
among them being several species and varieties of the genus 
Papaver, the bleeding heart, Dicentra spectabilis, and the Cali- 
fornia poppy, Eschscholtzia califormca. The bloodroot, Sangui- 
naria canadensis, a medicinal plant also belongs here. The opium 
poppy, Papaver somniferum, has been grown as a cultivated 
plant since ancient times. Opium is prepared from the white 
latex of the fruit, and this constitutes the source of a series of 
alkaloidal drugs, the chief of which is morphine. 




FIG. 119. The poppy family, Papaveraceae. A, leaf and flower of bloodiout, 
Sanguinaria (after Bail Ion}; B, bud and flower of poppy, Papaver (after Le M 
and Dec.); C, vertical section of a flowor of California poppy, Eschscholtzia 
(after Le M. and Dec.}; D, floral diagram of golden corydalis, Corydalix (after 
Le. M. and Dec.}; E, floral formula for the family; F, floral diagram of Papaver 
(after BaiUon}; G, floral diagram of Papaver (aftfr Le M. and Dec,}. 



THE CAPER FAMILY 

The capers or Capparidaceae are herbs, shrubs, and trees, 
largely confined to the tropics (Fig. 120). The family includes 
about 35 genera and 450 species of plants with watery sap. 

Leaves mostly alternate, rarely opposite, simple or digitately 
compound, leaflets entire; flowers mostly perfect, actino- 
morphic, sometimes zygomorphic, hypogynous, solitary and 
axillary or in terminal racemes; sepals 4 to 8, commonly 4, 
free or slightly united; petals 4 to 8, commonly 4, sometimes 0; 
stamens six to many, often long exserted ; ovary usually seated on 
a short or an elongated stipe (gynophore) or sessile, one-celled, 
with two to many parietal placentae, ovules many to few; 



THE TEAS, POPPIES, AND PINKS 



201 



fruit a capsule or berry, often borne on an elongated stalk above 
the corolla; endosperm scanty or 0. 

The "capers" of commerce are the pickled flower buds of 
Capparis spinosa, a plant of the Mediterranean region. Certain 
species of Cleome, especially C. spinosa, are known for their 
showy and peculiar flowers. 
This plant is known as the 
giant spider plant. Our 
western spider plant, Cleome 
serrulata, is a very conspic- 
uous species of the plains. A 

THE MUSTARD FAMILY 

This large family, the Cm- 
ci ferae, is commonly known 
as the mustard family (Fig. 
121) because of the genus 
Brassica, of many widely dis- 
tributed species known as 
mustards or coles. The long- 
established technical name, 
Cruci ferae, is in recognition of 
t he cross-like figure formed by 
the two sets of opposite petals 
radiating from the center of 
the flower. They are annual 

or perennial herbs, rarely shrubby, with watery juice, which is 
often acrid. There are about. 200 genera and 1,800 species 
included in the group, and they are very widely distributed, 
but are much more abundant in the temperate and cold parts of 
the world than in the tropics, many of them being arctic-alpine. 

Leaves alternate (rarely opposite), simple, but often deeply 
lobed or pinnatifid; flowers perfect, regular, small, but often 
showy because of being grouped in close racemes; sepals 4, free, in 
two series, falling early; petals 4, usually with a long claw and 
spreading limb; axis often glandular; stamens 6, in two sets, 
i.e. tetradynamous (4 long, 2 short); pistil sessile, of 2 united 
carpels, one-celled with 1 to 2 parietal placentae; stigmas often 2 
or completely connate; ovules many to few; fruit a globular or 
oval, flat, or greatly elongated capsule-like pod known as a 
"silicle" when about as broad as long, and as a "silique" when 




CAP B 



FIG. 120. The caper family, Cap- 
pandacrae. A, flowering stem of caper, 
Cappamt (after Le M. and Dec.}; B, 
floral formula for the family. 



202 



FLOWERS AND FLOWERING PLANTS 



longer than broad, usually opening by two valves; seeds small; 
endosperm 0. 

The mustard family contributes many products of much 
value to mankind and there are also numerous ornamental species 
included in the family. The cabbage is Brassica oleracea, of 
which there are a great many varieties in the usual sense that 
are cultivated, as well as other varieties that are known by some 
other name than cabbage. Among the latter are Brussels 
sprouts, B. oleracea gemmifera, cauliflower, B. oleracea botrytis, 
kohlrabi, B. oleracea caulorapa, and asparagus broccoli, B. 
oleracea italica. Closely related forms are rutabaga, Brassica 




FIG. 121. The mustard family, Crucifcrae. A, flowering and fruiting stem 
of moon wort, Lunaria (after Le M. and Dec.); B, flowering and fruiting stem of 
cabbage, Brassica oleracea (after Baillon); C, floral diagram of winteroress, 
Barbarea (after Le AT. and Dec.}; D, floral formula for the family. 

napobrassica, turnip, B. rapa, and black mustard, B. nigra. 
Watercress, Roripa nasturtium-aquaticum, and garden cress, 
Lepidium sativum, are prized for their fresh, peppery leaves, 
and the radish, Raphanus sativus, for its fleshy, peppery root. 
Ornamental species of mustards include sweet alyssum, Alyssum 
spp., candytuft, Iberis amara, and wallflower, Cheiranthus 
cheiri. There are also numerous persistent and noxious weeds 
in the family such as peppergrass, Lepidium spp., hedge mustard, 
Sisymbrium spp., pennycress, Thlaspi arvense, and western 
mustard, Sisymbrium altissimum. The moon wort or " honesty" 
is Lunaria annua, known for the purple flowers, but mainly for 
the thin, papery and shiny, translucent septum of the pod, 
sometimes nearly circular and 1 inch in diameter, that remains on 
the pedicel after the valves fall. 



THE TEAS, POPPIES, AND PINKS 



203 



THE MIGNONETTE FAMILY 

The members of the mignonette family, Resedaceae (Fig. 122), 
are annual or perennial herbs, with a few woody plants, with 
watery juice. They are grouped in 6 genera and 65 species 
that are largely indigenous to the Mediterranean basin. The 
popular plant of the florist and flower gardens by this name is 
Reseda odorata, grown for its very fragrant, yellowish flowers. 

Leaves alternate, simple, 
entire or often pinnately 
divided, stipules glandular; 
flowers usually irregular, 
perfect, hypogynous, race- 
mose or spicate; calyx 
four- to seven-lobed, zygo- 
morphic; petals 4 to 7, 
entire or cleft, small and 
inconspicuous or 0; sta- 
mens 3 to 40, inserted on 
an irregular fleshy disk, 
usually exserted beyond 
the petals even in the bud, 
filaments free or united 
below; ovary of 3 to 6 
separate or united carpels, 
often united into a one- 
celled ovary which is open 
at the top; stigma sessile; 
fruit a gaping capsule with 
many curved seeds; endo- 
sperm 0. 




CAP 



. 122. The mignonette family, Res- 
edaccae. A, flowering stem of mignonette, 
Reseda (after Raillon); B and C, single 
flowers of Reseda (after Baillon); D, floral 
diagram of Reseda (after Le M. and Dec.) 
E, floral formula for tho family. 



ORDER CARYOPHYLLALES, THE PINK ORDER 

This order includes a rather long list of cosmopolitan families 
from the true pinks or carnations, the Caryophyllaceae, to a 
number of apetalous families such as the Amaranthaceae and 
Chenopodiaceae, and the amentiferous, diclinous Salicaceae. 
The series represents another more or less variable group that 
has diverged from the Ranales somewhat later than have any 
of the preceding orders. 

The flowers are typically perfect and complete, but many are 
diclinous and apetalous; there are usually 4 to 5 sepals that are 



204 



FLOWERS AND FLOWERING PLANTS 



free, and 4 to 5 petals in the typical hypogynous, regular flower ; 
stamens as many or twice as many as the sepals; the pistil is 
superior and composed of 1 to 5 carpels, commonly 3, mostly 
one-celled, with many (rarely 1) ovules borne on a central or 
basal placenta; seeds usually with pcrisperm. . 

THE PINK FAMILY 

This is the Caryophyllaceae, a family of herbs including about 
70 genera and 1,200 species of annuals and perennials that are 
largely confined to the north temperate and colder regions of 
the earth (Fig. 123). 




FIG. 123. The pink family, Caryophyllaceae. A, flowering branch of pink 
Dianthus; B, fruit of same; C, vertical section of the flower of the same, D, 
floral diagram of starwort, Stellaria; E, floral diagram of Dianthus (all after 
Le M. and Dec,); F, floral formula for the family; G, flowering habit of corncockle, 
Agrostemma githago (aftrr Bentham). 

Leaves usually opposite or verticillate, simple, entire, often 
united at the base and attached to swollen nodes; flowers acti- 
nomorphic, perfect, hypogynous (or perigynous), axillary, solitary 
or cymose; sepals 3 to 5, persistent, free or slightly united; 
petals 3 to 5 or rarely wanting; stamens 8 to 10 (or fewer), free; 
ovary superior, three- to five-carpelled but one-celled, with central 
placentation ; fruit a capsule, opening by valves or terminal teeth; 
seeds many; perisperm present. 

Many of our most beautiful garden flowers are included in this 
family among which are various species of catchfly, Silene, 
Lychnis, pinks, Dianthus, and babysbreath, Gypsophila. The 
most popular and widely grown of all pinks is probably the car- 
nation or clove pink, Dianthus caryophyllus, of which there are 
scores of varieties grown under glass by the commercial florist. 



THE TEAS, POPPIES, AND PINKS 205 

Many of the cultivated forms produce double flowers that are 
very variable in size, color, form, etc. The old-fashioned soap- 
wort or bouncing bet is Saponaria officinalis. 

THE PURSLANE FAMILY 

The purslanes or pusleys are included in the family Portula- 
caceaej and they are mostly fleshy or succulent, often prostrate 
herbs or undershrubs, native largely to the western hem- 
isphere although certain ones are also widely distributed in the 
Old World. There are about 20 genera and 200 species. 

Leaves alternate or opposite, simple, sometimes united at the 
base, entire, often very fleshy or succulent; flowers hypogynous, 
actinomorphic, perfect, solitary or clustered; sepals usually 2, 
free or connate below; petals 4 to 5, or more, free or connate 
below, falling early; stamens same number as petals and opposite 
them, or many, free; ovary superior or partly inferior, one-celled, 
placenta basal, style two- to three-parted, ovules one to many; 
fruit a many-seeded capsule opening by 3 valves or by the forma- 
tion of an annular ring that separates a more or less conical cap 
from the upper part of the capsule (circumscissile) ; perisperm 
abundant, mealy. 

There are several popular flower-garden plants in this family 
including rosemoss, Portulaca grandiflora, with its cylindrical 
succulent leaves and showy flowers in bright colors of great vari- 
ety, usually opening only in sunshine. One of the most beautiful 
wild flowers of the family is the bitterroot, Lewisia rediviva, the 
state flower of Montana. Lewisia is named for Meriwether 
Lewis, the famous explorer of the northwest. 

THE GOOSEFOOT FAMILY 

The members of the Chenopodiaceae are mostly succulent, 
annual or perennial herbs, but there are numerous species that 
are distinctly shrubby, and they are widely distributed throughout 
the world especially along seashores and in saline areas in the 
interior of the continents. Many of them are known as "salt- 
bushes," because of their evident association with saline and 
alkaline sites (Fig. 124). 

Loaves and stems often mealy or scurfy (hence goosefoots); the 
leaves are usually alternate and simple; flowers commonly very 
small and inconspicuous, greenish, diclinous or perfect, hypo- 
gynous, actinomorphic, apetalous; plants sometimes dioecious; 



206 



FLOWERS AND FLOWERING PLANTS 



sepals 2 to 5, more or less united; stafriens of same number as 
calyx lobes and opposite them, sometimes fewer; pistil of 2 to 3 
carpels, one-celled, superior or imbedded in the calyx; style 1 to 3, 
terminal, ovule 1 ; fruit nut-like or an achene, more or less inclosed 
by the accrescent calyx; seed single; perisperm 0, or present 
and inclosed by the embryo. 

Some species of the family are grown for ornamental purposes, 
such as summer cypress, Kochia scoparia, but the more commonly 
used species are for food. The beets, including ordinary garden 
beets (beet root of the British), mangels, and sugar beets, Beta 
vulgariSj are the most useful plants of the group. Leaf beets 




FIG. 124. The goosefoot family, Chenopodiaceae. A t flowering stem of 
goosefoot, Chenopodium (aftfr Jj( j M. and Dec.}; B y single flower of the same; 
C, floral diagram for the family; D, flowering stems and flower details of Cheno- 
podium hybridum (after Bentham). 

and Swiss chard are other varieties of this species. Spinach, 
Spinacia oleracea, a valuable pot herb, i.e. grown for greens, 
also belongs here. 

THE AMARANTH FAMILY 

This is the Amaranthaceae, another large and widely dispersed 
family, the members of which are particularly abundant in warm 
climates. They are mostly annual and perennial herbs but there 
are a few woody species known, and about 40 genera and 500 
species have been described. 

Leaves alternate or opposite, simple, sometimes more or less 
fleshy; flowers small, dry, hypogynous, regular, usually perfect or 
diclinous, often massed in dense clusters mingled with colored 
scarious bracts or scales; sepals 3 to 5, free or slightly united; 
petals 0; stamens usually 5, opposite the sepals, free or united 
at base into a tube, staminodes sometimes present; ovary supe- 



THE TEAS, POPPIES, AND PINKS 



207 



rior, one-celled; style 1 or 0, stigma two- to three-lobed or capitate; 
ovules one to many; fruit capsule-like, (utricle) opening by a lid 
(i.e., circumscissile), sometimes more nearly an achene, or even 
berry-like. 

Besides the numerous weeds, pigweeds, etc. (Amaranthus, 
Acnida, etc.) that the family includes, the most noteworthy 
plant of the group is probably the cockscomb, Celosia cristata, 
with its many cultivated varieties and races. 

THE BUCKWHEAT FAMILY 

The Polygonaceae, commonly known as the buckwheats or 
knotweeds (Fig. 125), include another large series of apetalous 




NurAcH 



Fia. 125. The buckwheat family, Polygonaceae. A, habit sketch of sour 
dock, Rumex acetosella (Mathews); B, flower of buckwheat, Fagopyron (after 
Le M. and Dec.); C, floral diagram of Fagopyron (after Le M. and Dec.); D t 
same for Rumex; E, floral formula for the family. 

forms allied to the Caryophyllaceae. They include herbs, shrubs, 
and trees, some of which are climbers, arranged in 40 genera and 
800 species of very wide distribution in both warm and cold 
regions. The stems are conspicuously jointed and often swollen at 
the nodes, as in the pinks. 

Leaves alternate, rarely opposite or whorled, simple, stipules 
often forming a membranous sheath, the/ocrea, about the stem; 



208 



FLOWERS AND FLOWERING PLANTS 



flowers small, perfect or diclinous, regular, often in spikes or 
racemes; sepals 3 to 6, separate or slightly united, often becoming 
greatly enlarged, winged, spiny, and brightly colored in fruit; 
petals 0; stamens 6 to 9, rarely more, filaments free or united; 
ovary superior, sessile, with 2 to 4 carpels, but one-celled, styles 
2 to 4, free ; fruit an indehiscent, three-angled or lenticular nut or 
achene, sometimes inclosed by the enlarged calyx; seeds with 
abundant, mealy endosperm. 

The common buckwheat, Fagopyron esculent um, is the most 
useful plant in the family as a cultivated plant of several varieties, 
from the fruits of which the familiar buckwheat flour is prepared. 
The plant is not strictly a wheat at all, since the wheats in the 
botanical sense are all grasses of the genus Triticum. The term is 
probably a modification of "beech wheat, " from the resemblance 
of the fruits to beechnuts, and the fact that a flour is prepared 
from the seeds. The common rhubarb, Rheum rhaponticwm, also 
belongs here, as do various species of Polygonum, some of which 
are valued for the beautiful spikes of white or purple flowers. 

THE FOUR-O'CLOCK FAMILY 

The family Nyctaginaceae includes about 25 genera and 350 
species of herbs, shrubs, and trees of wide distribution but mainly 
in tropical and temperate America. They are called four 




FIG. 126. The four-o'clock family, Nyctaginaceae. A, single flower of four- 
o'clock, Mirabilis; B, fruit of the same; C, floral diagram of Mirabilis (all after 
Baillori); >, floral formula for the family. 

o' clocks because of the fact that the flowers in certain members of 
the group (Mirabilis) open in greatest numbers in late afternoon 
(Fig. 126). 

Leaves alternate or opposite, simple; flowers perfect or dicli- 
nous, hypogynous, regular, usually subtended by an involucre 
of separate or united, brightly colored bracts that are often 
mistaken for a perianth; calyx tubular, with 4 to 5 wide-spread- 
ing lobes, often petaloid; petals 0; stamens one to many, free or 
united at the base; ovary superior, one-celled, one-ovuled, 



THE TEAS, POPPIES, AND PINKti 



209 



sessile or stalked ; fruit dry, indehiscent, often ribbed or grooved, 
sometimes inclosed in the persistent calyx, often glandular; 
perisperm abundant or scanty. The brightly colored bracts 
often persist about the fruits long after the flowers have withered. 
A few species of four o'clocks are cultivated for ornamental 
purposes, among which are the bushy, herbaceous four o'clock 
of the garden, Mirabilis jalapa, and the gorgeous Bougainvillea 
(or Buginvillaea) , a popular ornamental vine of warm countries, 
with its great masses of purple or magenta bracts. The common 
species, B. glabra, is a native of Brazil. 

THE WILLOW FAMILY 

The willow family, Salicaceae, includes the cottonwoods, 
aspens, and poplars, Populus, as well as the willows, Salix (Fig. 
127). They are trees or shrubs, but several of the willows of 




FIG. 127 The willow family, Salicaceae. A, leaves and pistillate catkin of 
sandbar willow, Salix longifolia; B, twig of same species with staminate catkins 
(after Mat hews); C, staminate catkins of cottonwood, Populus (after Le M. and 
Dec.}; D, staminate catkin of willow, Salix (after Le M. and Dec.}; E, leaves, 
staminate catkin, staminate and pistillate flowers of peaoh-leaved willow, Salix 
amygdaloides (after Mathews); F, floral formula for the family. 

Arctic-alpine situations are dwarfed, carpet-like plants, like 
many herbaceous, more or less woody perennials. These plants 
are grouped into two genera and about 200 species with a very wide 
distribution, but they are most abundant in the temperate and 
cold portions of the northern hemisphere. They are absent from 
Australasia and the Malay Archipelago. Many of the tree 



210 FLOWERS AND FLOWERING PLANTS 

species of both genera grow rapidly. The wood of most of the 
species is usually light and soft. 

Leaves alternate, simple, deciduous, petioles often glandular; 
stipules sometimes foliaceous and persistent; the species are 
dio3cious; flowers densely clustered in erect or pendulous catkins 
appearing before or with the leaves; each flower in the axil of a 
more or less hairy, membranous, fugacious or persistent bract; 
calyx or reduced to a small disk or to a few glandular scales; 
petals 0; stamens 1, 2, or more, filaments slender, free or more or 
less united; ovary sessile or short-stalked, one-celled, with 2 to 4 
parietal placentae, stigma two- to four-lobed, ovules numerous; 
fruit a two- to four-valved, one-celled capsule with many hairy 
seeds; endosperm none. 

Numerous willows are used for ornamental purposes, especially 
the weeping willow, Salix babylonica, of which there are several 
varieties and hybrid forms, the yellow willow, S. vitellina, and 
white willow, S. alba. Other species, such as S. viminalis, and 
S. purpurea, are used in basket making. The poplars or cotton- 
woods, i.e., species of Populus, are also used for ornamental plant- 
ing as well as for windbreaks and woodlots. Popular orna- 
mentals are the white poplar, Populus alba (often called silver 
maple), and the closely related bolleana poplar, P. bolleana, with 
its narrow, erect crown, and the Lombardy poplar, P. nigra, 
var. italica. The proper name for the common cottonwood, 
widely planted in the prairie and plains area of North America, 
appears to be P. deltoides Marshall, of which there are several 
varieties. 



CHAPTER XV 



THE PRIMROSES, HEATHERS, AND EBONIES 

The members of these orders are herbs, shrubs, or trees and are 
largely characterized by regular flowers in which the petals are 
united to form a more or less tubular or campanulate corolla, a 
strong tendency toward epipetalous stamens, and with a superior 
or inferior ovary composed of several or a few united carpels. 
Sympetaly is clearly established on a broad scale, and epigyny 
is also definitely introduced in the families of these orders. 

ORDER PRIMULALES, THE PRIMROSE ORDER 

The families included in the Primulales, or primrose order, are 
mostly herbs, with regular, perfect, 4- to 5-parted flowers, epipet- 
alous stamens, and a one-celled ovary composed of several 
carpels, or the axial or basal 
placentae showing little evi- 
dence of more than one carpel 
in the mature ovary. 




Fio. 128. The primrose family, 
Primulaceae. A, habit of primrose, 
Primula farinosa; B, pistil of same; C, 
flower of same (after Bentham); D, 
floral diagram of Primula (after Le M. 
and Dec.); E, floral formula for the 
family. 



THE PRIMROSE FAMILY 

The members of the Primula- 
ceae or the primrose family (Fig. 
128), are annual or perennial 
herbs, including about 30 
genera and 700 species distrib- 
uted in abundance mostly in 
the temperate portions of the 
northern hemisphere. They are 
common in the mountain areas of the north but are rare in the 
tropics and southern hemisphere. 

Leaves alternate, opposite, or whorled, sometimes all basal, 
simple, regular or lobed, frequently glandular; flowers perfect, 
actinomorphic, solitary or in various types of bracteate clusters; 
calyx four- to five-parted, persistent, often becoming foliaceous; 
corolla tubular, sympetalous, the tube short or long, the 4 to 5 

211 



212 



FLOWERS AND FLOWERING PLANTS 



lobes commonly spreading; stamens 4- to 5, inserted on the corolla 
tube opposite the petals; ovary superior (rarely somewhat 
inferior), one-celled, with 2 to 6 carpels or basal placentae, ovules 
many; fruit a capsule; seeds with abundant endosperm. 

This family includes many very showy wild flowers and culti- 
vated plants of gardens and conservatories. Several species of 
Primula, notably P. sinensis, the Chinese primrose, with its 
many varieties and cultivated forms, are very popular members 
of the florist's lists of indoor flowers. The cyclamens are also 
widely cultured for decorative purposes. The rock jasmines, 
Androsace spp. shooting stars, Dodecatheon spp., and wild prim- 
roses, Primula spp., are familiar plants to one who tramps and 
climbs among the mountains. 

THE PLANTAIN FAMILY 

This is the Plantaginaceae, a group that should not be confused 
with the Musaceae, the banana family, and the Bromeliaceae, 

the pineapple family, which 
are also known as "plantains" 
in certain parts of the world 
(Fig. 129). There are 3 
genera and about 2,30 widely 
dispersed herbaceous, annual 
or perennial species in the 
family. 

Leaves alternate or oppo- 
site, or all basal, simple; 
flowers small, perfect or 



. diclinous, actinomorphio, in 

Fio. 129.-The plantain family. Plan- dense terminal, bracteate 

taginaceae. A, habit sketch ond details Spikes Or heads On elongated 

of the flowers of plantain, Plantaqo major qpnT . ,>1 VY f mir nnrfpd 

(after Bentham), B, floral formula for the =*' d i* J > Cdiyx luui p<u tt,u, 

family; C, floral diagram of Plantago (after inferior, persistent; Corolla 

Le M. and Dec.). sympetalous, usually four- 

lobed, scarious; stamens 2 or 4, on the tube or throat of the 
corolla and alternate with the lobes; ovary superior, one- to four- 
celled, commonly two-celled, style simple, slender, ovules 1 or 
more in each cell; fruit a circumscissile capsule (pyxis), or a 
nutlet, with one seed in each cavity; seeds with fleshy endosperm. 
The species in this family possess little or no commercial 
value, but some of them are of economic significance on account of 




THE PRIMROSES, HEATHERS, AND EBONIES 213 

their persistent weedy nature. Common weeds in the group are 
Plantago major, P. lanceolata, a common adulterant of alfalfa seed, 
and P. purshii. A mucilaginous beverage is made from spagel 
seeds obtained from the Indian P. ovata, or ispaghul. 

THE LEADWORT FAMILY 

This, the Plumbaginaceae, is a family of herbs, shrubs, and vines 
with 10 genera and about 300 species found widely on maritime 
shores and in other saline situations, particularly in the Mediterra- 
nean basin. They arc commonly known as sea lavenders, sea 
pinks and leadworts (Fig. 130). 



i^A'te/ *; 




FL.SCARIOUS D 



FIG. 130. The lead wort family, Plumbaginaceae. A, seapink, Staticc armeria; 
B, single flower of same (after ^fathews}; C, single flower of Plumbago (after 
Lf .\f. and Dec.}; />, floral formula for the family, E, floral diagram of Stalice. 

Leaves alternate or grouped in a basal rosette ; flowers perfect, 
actinomorphic, in dry bractcd spikes, heads or panicles that are 
often unilateral; calyx tubular or funnel form, five-lobed or 
five-toothed, bracted at base, often ribbed, plaited, scarious and 
colored; corolla tubular, five-lobed, often dry and persistent; 
stamens 5, epipetalous, opposite the corolla lobes ; ovary superior 
one-celled, ovule 1, styles 5, separate or united; fruit indehiscent, 
or opening late, usually inclosed by the calyx; seed with or 
without endosperm. 

Several species, especially of Limonium and Statice, are widely 
grown in gardens and hothouses for ornamental purposes. 
Various species are very popular for "dry bouquets" and for the 
preparation of wreaths and sprays for memorial purposes. The 
leadwort, Plumbago capensis, is frequently seen as a sprawling 
vine in conservatories where it is prized for its bright blue 



214 



FLOWERS AND FLOWERING PLANTS 



flowers that resemble the flowers of wild sweet william, Phlox 
divaricata. 

ORDER ERICALES, THE HEATHER ORDER 

This order includes the heaths, heathers, and wintergreens. 
They have regular, perfect, actinomorphic, pentamerous, sym- 
petalous flowers, in which the stamens are usually hypogynous 
and the ovary is usually superior and composed of two to many, 
united carpels, with numerous minute seeds. 

THE HEATHER FAMILY 

The Ericaceae, commonly known as the heather or heath 
family, are a large group of shrubs or small trees with mostly 
evergreen leaves, of about 70 genera and 1,400 species of very 




FIQ. 131.- The heather family, Ericaceae. A, one-flowered wintergreen, 
Moneses uniflora; B, single flower of bearberry, Arctostaphylos; C, sectional 
view of flower of Arctostaphylos; Z>, stamen; E, section of ovary, F, floral diagram 
of wintergreen, Pyrola; G, floral diagram of blueberry, Vaccinium; H, floral 
diagram of heather, Erica; I, floral formula for Erica sp., J, flowering twig, 
section of a flower, and cluster of fruits of mountain laurel, Kalmia latifolia 
(after Sargent). B, C, D, E, redrawn from Watmmg-Potter, Systematic Botany, 
published by The Macmillan Company. 

wide geographical distribution, especially in relatively cool 
climates (Fig. 131). Many species are found in South Africa 
and Western China. 

Leaves alternate or whorled, simple, often more or less leathery, 
and commonly evergreen; flowers perfect, usually actinomorphic, 
solitary or in terminal or axillary racemes or panicles; calyx 
four- to five-cleft or parted, persistent; corolla sympetalous, four- 
to five-lobed, inserted below a fleshy disk; stamens commonly 



THE PRIMROSES, HEATHERS, AND EBONIES 215 

twice as many as corolla lobes, inserted on the outer edge of the 
disk or on the corolla, filaments free, anthers opening by 
terminal pores; ovary superior or inferior, two- to five-celled, 
ovules one to many in each cell, style and stigma 1; fruit a 
capsule, berry, or drupe; endosperm fleshy. 

This family contributes many plants of great value as orna- 
mentals as well as several that are prized in cultivation and in the 
wild state for their edible fruits. The rhododendrons and the 
azaleas are among the most beautiful of ornamental plants that 
are widely grown in parks and conservatories. The state flower 
of Washington is Rhododendron calif ornic urn. Several heaths, 
Erica spp. and heathers, Calluna, and the laurel, Kalmia, are 
also highly prized for their beauty of flower and foliage. The 
blueberries, huckleberries and cranberries, species of Vaccinium, 
trailing arbutus, Epigaea, and wintergreen, Gaulihma, also 
belong to this family as here treated, although some authors 
distribute these among two or three other families. 

ORDER EBENALES, THE EBONY ORDER 

These are trees and shrubs which closely resemble the Ericales 
in flower structure. The stamens are usually epipetalous in 
this group but in the heathers they are more commonly hypogy- 
nous. Both these orders are doubtless more primitive than 
the Primulales. 

THE EBONY FAMILY 

The plants of the Ebenaceae are trees and shrubs with very 
hard, dark wood, classified into 6 genera and about 275 species dis- 
tributed mostly in tropical and subtropical countries (Fig. 132). 
The persimmon, Diospyros virginiana, of North America is often 
seen in temperate climates. 

Leaves alternate, entire, often leathery; flowers regular, usually 
diclinous, often polygamo-dioecious, sometimes perfect, solitary 
or cymose in the axils of the leaves; calyx three- to seven-lobed, 
persistent, often enlarging in fruit; corolla three- to seven-lobed, 
sympetalous; stamens two to four times the number of corolla 
lobes, hypogynous or epipetalous, filaments free or united at 
base in pairs; ovary superior, three- to many-celled, ovules 1 to 2 
in each cell, styles few to many, free or united; fruit a berry which 
is sometimes more or less leathery; seeds with endosperm. 



216 



FLOWERS AND FLOWERING PLANTS 



The ebony family furnishes many useful products. The ebony 
wood of the Orient is secured from Diospyros ebenum, a close 
relative of our American persimmon. Hard and heavy woods 
are produced by other genera and species also. The persimmons 




FIG. 132. The ebony family, Ebenaceae. A, flowers and leaves of persimmon, 
Diospyros mnjiniana; B, ripe fruit of same; C, section of same (after Gafjer); 
D, floral diagram of pistillate flower of persimmon, K, floral diagram of stammate 
flower of persimmon (after Le M. and Dec.); F, floral formula for the family 

are important also for the fruits that they produce, especially 
those of the Kaki plum, or Japanese persimmon, Diospyrox 
kaki. 

The sapodilla family, Sapotaceae, and the storax family, 
Styracaceae, are also included in this order under the Besseyan 
system. 



CHAFFER XVI 
THE GENTIANS, PHLOXES, SNAPDRAGONS, AND MINTS 

This group of orders is characterized by many families that are 
largely herbaceous, and by the presence of perfect (rarely dicli- 
nous), sympetalous flowers, in which the superior ovary is typi- 
cally bicarpellary, and the stamens are epipetalous and alternate 
with the corolla lobes. A high degree of zygomorphy is also 
developed, especially in the snapdragons, Scrophulariales, and 
in the mints, Lctmiales. 

ORDER GENTIANALES, THE GENTIAN ORDER 

The gentian order includes families in which the flowers are 
perfect, actinomorphic, mostly five-lobed or five-parted, the 
stamens are of the same number as the corolla lobes and alternate 
with them, and the bicarpellary ovary is superior. The leaves 
are usually opposite. The order also embraces the Oleaceae or 
olive family in which the petals are often lacking and the flowers 
are sometimes diclinous. 

THE GENTIAN FAMILY 

The Gentianaceae are a large group of annual or perennial herbs 
(a few are woody) arranged in about 65 genera and 750 species 
with wide distribution, but more abundant in temperate and 
subtropical regions (Fig. 133). 

Leaves opposite (rarely alternate), often more or less connate 
at base; flowers perfect, regular, in axillary or terminal cymes, 
often brightly colored and showy; calyx tubular (rarely of sepa- 
rate sepals), usually five-lobed (4 to 12); corolla sympetalous, 
tube short or long, usually five-lobed (four- to twelve-lobed) ; sta- 
mens same number as corolla lobes and alternate with them, 
epipetalous ; ovary superior, one-celled or with two, parietal placen- 
tae (bicarpellary), style simple, ovules numerous; fruit a capsule; 
seeds with abundant endosperm. 

The family contains many species with very beautiful flowers 
that are cultivated, particularly in the rock gardens of Europe. 
Many of them have blue flowers and some of these have beauti- 

217 



218 



FLOWERS AND FLOWERING PLANTS 



fully fringed corolla lobes, as in the fringed blue gentians, 
Gentiana crinita and Anthopogon elegans. The gentians are often 
conspicuous in montane floras. 




FIG. 133. The gentian family, Gentianaccae. A, flowering habit of fringed 
gentian, Gentiana crinita (Afathewx); B, a dwarf alpine species of Gentiana; C, 
floral diagram of gentian (after Le M. and Dec.}, D, single flower of Euxtoma 
(after Baillon); E, floral diagram for the family. 

THE OLIVE FAMILY 

The Oleaceae or olive family, is doubtless the most important 
family of the Gentianales. These are trees and shrubs in about 




FIG. 134. The olive family, Oleaceae. A, flower cluster of lilac, Syringa 
vulgaris (after Baillon); B, single flower of Syringa (after Baillon); C, flower of olive, 
Olea europea (after Baillon); D, floral diagram of lilac, Syringa (after Le M. 
and Dec.); E, vertical section of a flower of olive, Olea (after Baillon); F, floral 
formula for the family. 

20 genera and 500 species that are widely dispersed in temperate 

and tropical regions of both the Old and New World (Fig. 134). 

Leaves opposite (rarely alternate), simple or commonly 

pinnately compound, often evergreen; flowers regular, perfect, 



GENTIANS, PHLOXES, SNAPDRAGONS, AND MINTS 219 

polygamous, or dioecious; calyx four-lobed or four-toothed, 
rarely 0; corolla sympetalous or petals free or none (red ash); 
stamens usually 2, (3 to 5 rarely) commonly epipetalous; ovary 
superior, two-celled, with two or more ovules in each cell, style 
simple with bifid or capitate stigma; fruit a capsule, drupe, 
berry, or samara; endosperm usually present. 

There are many highly prized and popular ornamental plants 
in this family, including several species of privet, Ligustrum, for 
hedges, the jasmines, Jasminum, lilacs, Syringa, of many species 
and varieties, and the ashes, Fraxinus, among which are impor- 
tant forest trees as well as those that are valuable ornamentals. 
The white ash, Fraxinus americana, and the European ash, F. 
excelsior, are well known. 
The olive, Olea europea, of 

Southeastern Europe and ^JIIA^TO^ mj I " <&& <A \ 
Asia Minor is widely cul- / ^^^ & vL%/ ) 
tivated in warm climates, (&U>\r^ VN N-!=tf X/ 

as in California and Italy 
for its edible fruits, the 
olives of commerce. 

THE DOGBANE FAMILY 





There are about 130 * A ^~^ C BAC DR FOL 

genera and 1,100 Species FlG - 135. The dogbane family, Apocy- 
f .-,, - j v v i naceae. A, plant of periwinkle, Vinca minor, 

of milky-juiced shrubs and with leavcs aml flower; n floral diagram of 

trees included in the Apo- samc (after Le M.and Dec.); C, floral formula 
, , /. for the family. 

cynaceae, or dogbane fam- 
ily. Some of them are climbers and a few are perennial herbs (Fig. 
135). They are most abundant in the tropics and sub tropics. 

Leaves opposite, whorled or alternate, simple, entire; flowers 
perfect, actinomorphic ; calyx four- to five-lobed, often with glands ; 
corolla tubular, four- to five-lobed; stamens 4 to 5, epipetalous, 
free or filaments rarely united; anthers sometimes connivent 
about the stigma; ovary superior, two-celled, syncarpous or one- 
celled with two parietal placentae or carpels 2, free or united 
only at base, style 1, ovules 2 or more in each carpel; fruit 
indehiscent or more commonly of two separate carpels, berry-like, 
drupaceous, or follicular; seeds often hairy or winged ; endosperm 
present. 

A number of species in this family produce fruits of value such 
as the karaunda, Carissa carandas, of India, arrow poisons are 



220 



FLOWERS AND FLOWERING PLANTS 



prepared from Acokanthera schimperi in east tropical Africa, 
and certain ones are valuable ornamentals, among which are 
the oleanders, Nerium, and the periwinkles, Vinca. 

THE MILKWEED FAMILY 

The milkweeds, Asclepiadaceae, are milky-juiced herbs, vines, 
or shrubs of wide geographical distribution, most numerous in 
the warmer regions of the earth, and very common in South 
Africa, but comparatively rare in cold climates (Fig. 136). 

Leaves opposite or whorled, rarely alternate, simple, usually 
entire; flowers perfect, regular, in terminal or axillary umbels or 

cymes; calyx of 5 separate 
or connate sepals; corolla 
sympetalous, five-lobed or 
five-parted; an additional 
structure of the nature of 
a five-lobed crown (corona) 
arising from the corolla and 
stamens present inside the 
corolla; stamens 5, on the 
base of the corolla alter- 
nate with the lobes, fila- 
ments united into a 
column, anthers adherent 
to or connivent about the 

Km. 130. The milkweed family, Asdcpt- stigma, the pollen coherent 
adaceae. A, flowering habit f butterfly in waxy or granular masses 

weed, Axclepias tuberosa (after Mathcws}; B, , n- \ , i i o> 

single flower of milkweed, A.cle^as (after (poUima) attached in 2's 

Baillori); C, flower with petals removed; D, or 4's to the Stig Ilia directly 
floral diagram of Asclepias (after Le M. and i_ i i i 

Dec.);E, floral formula for the family. or b y arched Corpuscula; 

ovaries 2, or ovary of 2 

more or less united carpels, superior, with ventral placentae, 
short styles united to form a short, thick, discoid stigma; fruit 
2 follicles, often widely divergent, each with many seeds crowned 
with a tuft of silky hairs, endosperm scanty; embryo large. 
A few species of milkweeds are planted for their ornamental 
values in wild gardens such as butterfly weed, Asclepias tuber osa, 
and swamp milkweed, Asclepias incarnata, and certain climbers, 
Araujia and Stephanotus, are grown under glass or out of doors in 
warm countries as in Brazil and Madagascar. Certain ones, 
such as Asclepias syriaca, are sometimes troublesome weeds, as 




GENTIANS, PHLOXES, SNAPDRAGONS, AND MINTS 221 

the boy on the farm may testify. The flowers of many species 
of milkweed are very fragrant, but certain ones, as Stapelia 
variegata, emit a carrion-like odor. * 

ORDER POLEMONIALES, THE PHLOX ORDER 

The phloxes and their kin, the order Pokmoniales, consist of a 
group of families that are closely related and that have been so 
regarded for a great many years. Their relationship to the orders 
that are placed lower in this series, i.e. the Primulales and 
Caryophyllales, appears to be quite clear. The order is much 
more restricted in this treatment than in the Engler system. 

The flowers are typically actinomorphic, but with a decided 
tendency toward the development of zygomorphy in certain 
families, sympetalous, pentam- 
erous; stamens epipetalous, 
same number as corolla lobes 
and alternate with them ; ovary 
tripcarpellary, or bicarpellary, 
superior; leaves usually alter- 
nate; largely herbs or climbers. 




THE PHLOX FAMILY 

The phloxes, Polemoniaceae, 
are mostly annual or perennial 
herbs, with few woody plants 
of the nature of low trees or 
climbing shrubs, mostly of the FlG - i37.~The phlox family Pole- 

momaceae. A, flowering habit of a wild 

western hemisphere, rare in phlox or sweet wiliiam, Phlox pilosa; 

Europe and Asia (Fig. 137). f floral diagram for phlox; C floral 
^ formula for the family (after Mathews). 

The family includes 10 to 12 

genera and about 270 species of wide distribution in the 

Americas. 

Leaves alternate or opposite below, simple, usually entire, 
sometimes pinnate or palmate; flowers perfect, regular or nearly 
so, often crowded in heads or corymbs; calyx five-lobed; corolla 
of 5 united petals, tubular, with spreading lobes; stamens 5, 
epipetalous, alternate with corolla lobes; ovary superior, inserted 
on a disk, sessile, composed of 3 (or rarely 2) united carpels; 
ovules one to more in each cell, placentae axile,. style 1, stigmas 
commonly 3 (rarely 2); fruit usually a dehiscent capsule; seeds 
few or many, with abundant endosperm. 



222 



FLOWERS AND FLOWERING PLANTS 



Many members of this family are grown for horticultural 
purposes, and numerous wild species are highly ornamental. 
The premier group is doubtless Phlox, of which several species 
are cultivated. The North American P. divaricata, of the east- 
ern woodlands, P. pilosa of the prairies, and P. stansburyi of the 
Great Basin are worthy of note. 

THE MORNING-GLORY FAMILY 

Morning-glories, in the botanical sense, are members of the 
natural family Convolvulaceae. They are mostly annual or 
perennial herbs, many of which are climbers, and a few are woody. 

There are 50 genera and about 1,000 
very widely distributed species in- 
cluded in the family; particularly 
abundant in the tropics (Fig. 138). 
Leaves alternate, simple or rarely 
compound (juice sometimes milky) 
reduced to inconspicuous scales in 
the Dodders (Cuscuta); flowers per- 
fect, actinomorphic, sometimes 
subtended by a bracteose involu- 
cre ; sepals 5, free or united ; petals 
5, united, forming a funnel-shaped 
corolla with flaring rim, usually 

Fio. 138. The morning-glory ,.,j. LJ , - . , 

family, Convohndaccae. A, leaf twisted in bUOJ Stamens .0, eplpeta- 

and flower of bindweed, Convohu- l O us, alternate with corolla lobes; 

lus (after Le M. and Dec.}; B, flora,! . -, , , 

diagram of bindweed, Convolvulus ovary superior or surrounded by a 
(after LeM. and Dec.); C, floral for- disk, one- to three-celled, usually 

mula for the family. . tl , , ,., 

two-celled, ovules solitary or 

paired in each cell; fruit a capsule, opening by valves; seed with 
meager endosperm. 

This family includes an interesting series of parasitic morning- 
glories known as the dodders, included in the genus Cuscuta. 
About 55 species of Cuscuta have been described, among which 
are species that attack such plants as alfalfa, flax, mint, willow, 
and many common weeds. Many bothersome weeds are also 
included in the family, such as the common field morning-glory, 
Convolvulus septum, and the little bindweed, C. arvensis. Orna- 
mental species are Ipomoea purpurea, the common purple morning- 
glory, and the so-called cypress vine, Quamoclit pennata. The 
most valuable plant of the family is the sweet potato, Ipomoea 




GENTIANS, PHLOXES, SNAPDRAGONS, AND MINTS 223 

batatas, a true morning-glory, grown extensively for its large, 
edible, fleshy-fibrous roots. 

THE WATERLEAF FAMILY 

The Hydrophyllaceae include 18 genera and about 225 species 
of annual and perennial herbs of wide distribution, but evidently 
more abundant in North America than elsewhere. The group 
is commonly known as the waterleaf family because certain 
members of the family, Hydrophyllum, were supposed to have 
cavities in the leaves for holding water. 

Leaves alternate or radical, rarely opposite, entire or variously 
lobed; the whole plant often rough-hairy; flowers perfect, regular, 
often in rough scorpioid cymes; calyx deeply five-parted; corolla 
sympetalous, five-lobed, lobes erect or spreading; stamens 5, 
inserted on the corolla tube and alternate with the lobes, free; 
ovary with 2 parietal placentae or two-celled, styles 2, separate 
or united and two-cleft; fruit a two-valved capsule; seeds with 
fleshy endosperm. 

Numerous forms of the family are grown for ornamental 
purposes such as blue eyes, Nemophila insignis, California blue- 
bell, Phacelia whitlavia, and golden bells, Emmenanthependuliflora. 
One species, Hydrophyllum canadense, is listed as a drug plant. 

THE NIGHTSHADE FAMILY 

The Solanaceae are a family of herbs, climbing vines, and a few 
small trees of about 75 genera and 2,000 species of wide geo- 
graphical distribution in temperate regions and very abundant 
in tropical countries (Fig. 139). 

Leaves alternate, entire or variously lobed, or pinnately com- 
pound; flowers perfect, actinomorphic, sympetalous; calyx five- 
lobed persistent; corolla five-lobed, often rotate, but much 
variation in form and structure, sometimes zygomorphic; sta- 
mens as many as the lobes of the corolla and alternate with them; 
ovary superior, two-celled, with axile placentae, ovules many, 
style 1, stigma simple, or lobed; fruit a capsule or berry; seeds 
with abundant endosperm. 

This family includes many plants that furnish foods and drugs, 
and species that are highly decorative as well as numerous 
poisonous plants. Among these is the genus Solarium including 
jS. tuberosum and S. melongena, the Irish potato and the eggplant 



224 FLOWER8 AND FLOWERING PLANTS 

respectively, also Lycopersicon esculentum, the tomato, among the 
world's most valuable food plants; the drug plants belladonna, 
Atropa belladonna, the henbane, Hyoscyamus niger, and the jimson 
weed, Datura stramonium, as well as tobacco, Nicotiana tabacum, 
and Capsicum frutescens, the numerous varieties of which are 
known as peppers ; and the highly ornamental petunias, Petunia 
violacea, salpiglossis, Salpiglossis sinuata, and matrimony vine, 
Lycium halimifolium. 




BER CAP 



FIG. 139. The nightshade family, Solanaceae. A, flowers and leaves of 
potato, Solanum tubcrosum (after Le M. and Dec.}; B, floral diagram of same 
(after Le M. and Dec.); C, floral tormula of the family combining actmomorphic 
and zygomorphic forms in one formula, D, floral formula for the family including 
actinomorphic forms only; E, flowering and fruiting branch of ground cherry, 
Physalis alkakengi (after Baillon); F, floral diagram of tobacco, Nicotiana (after 
Le M. and Dec,), 

THE FORGET-ME-NOT FAMILY 

The members of the Boraginaceae are commonly known as the 
forget-me-nots, puccoons, and borages (Fig. 140). They an; 
mostly herbs, but the group also includes a few shrubs and trees, 
grouped in 86 genera and about 1,500 species, that are widely 
dispersed through temperate and tropical regions, and are 
abundant in the Mediterranean Basin. 

Leaves alternate, simple, mostly entire, rarely opposite; whole 
plant often rough-hairy; flowers often blue or white, in scorpioid 
racemes or cymes, perfect, actinomorphic or rarely somewhat 
oblique; calyx five-cleft, persistent; corolla five-cleft, often 
appendaged in the throat; stamens 5, inserted on the tube or 
throat, alternate with the corolla lobes; ovary of 2, united and 



GENTIANS, PHLOXES, SNAPDRAGONS, AND MINTS 225 

deeply two-lobed carpels or entire, ovules one in each lobe; fruit 
usually 4, more or less bony nutlets, each with 1 seed, or some- 
times 2 nutlets each with 2 seeds, rarely drupaceous or berry- 
like; nutlets attached to fruiting axis by base or at the side; 
endosperm present or 0. 

The forget-me-not of popular acclaim is quite different in 
different areas. A common plant by this name is Myosotis 
arvensis, but the common forget-me-not in the Rocky Mountains 
is Mertensia alpina or Eritrichium argenteum, all of which have 
the bright, blue flowers necessary to qualify as forget-me-nots in 



S! 




1-4 NUTLETS 




FIG. 140. The forget-me-not family, Boraginaccae. A, flowering stem of 
forgct-me-riot, Afyonotia (after Le M. and Dec.}; B, floral diagram of a borage 
(after Le M. and Dec.}; (7, floral formula for the family. 

the popular sense. The common heliotrope, Heliotropium peru- 
vianum, also belongs here, as do many other beautiful species 
and varieties. 



ORDER SCROPHULARIALES, THE SNAPDRAGON ORDER 

This order has much in common with the Polemoniales, but is 
readily separated from the latter by the almost universal zygo- 
morphy and the fact that the number of stamens is usually 
less (4 or 2) than the number of corolla lobes. The ovary is 
usually two-carpelled, and the fruit a capsule with many seeds. 
The group also includes the curious, leafless parasites known as 
broomrapes, Orobanchaceae, as well as the interesting, carnivorous 
bladderworts, Lentibulariaceae. 



226 



FLOWERS AND FLOWERING PLANTS 



THE SNAPDRAGON FAMILY 

The family Scrophulariaceae, is known as the snapdragon, 
figwort or foxglove family (Fig. 141). The scientific term is 
from the genus, Scrophularia, named in recognition of the belief 
that a certain species, $. nodosa, was a remedy for scrofula. 
They are mostly herbs of temperate regions, but many shrubs 
and trees of the tropics belong in this family, and they are very 
widely distributed. There have been about 75 genera and 3,000 
species described that are assigned to this family. 

Leaves alternate, opposite, or whorled; flowers perfect, zygo- 
morphic (rarely almost actinomorphic), calyx four- to five- 

toothed or -divided, persistent; 
corolla sympetalous, often strongly 
two-lipped, rotate or carripanulate; 
stamens usually 4, didynamous, or 
2, sometimes accompanied by a 
sterile stamen (in Pentstemon), 
inserted on the corolla tube and 
alternate with its lobes, sterile 
stamen sometimes reduced to a 
gland or scale; ovary superior, 
sessile, usually bicarpellary, ovules 

each Cell > st y le entire or 





CAP 



FIG. 141. The snapdragon fam- 

ly, Scrophulariaceae. A, flowering two-lobed; fruit Usually a Capsule; 
stem of snapdragon, Antirrhinum d numerous, with 
majus (after Mathews); B, floral ' 

diagram of snapdragon (after Le endosperm. 
,/ , floral formula for r PV/--M^. 

i nere 



fleshy 



are nume us species in 
this family with showy flowers and 

combinations of color pattern and form that are very attrac- 
tive. The foxglove, Digitalis purpurea, is an old-fashioned 
ornamental and drug plant, and snapdragons, Antirrhinum 
majus, with its numerous varieties, the beardtongues, Pentstemon 
spp., monkey flowers, Mimulus spp., and slipperworts, Calceolaria 
spp., are other prized plants of gardens and plant houses. 



THE BIGNONIA FAMILY 



The Bignoniaceae include about 100 genera and 600 species of 
trees, shrubs and woody vines (and a very few species of herbs) 
with a wide distribution in tropical and subtropical regions 
and few in temperate climates (Fig. 142). 



GENTIANS, PHLOXES, SNAPDRAGONS, AND MINTS 227 

Leaves opposite, rarely alternate, or whorled, simple or com- 
monly compound, palmate or pinnate; flowers perfect, zygo- 
morphic, often very showy, in terminal or axillary racemes or 
panicles; calyx carnpanulate or tubular, five-lobed or not lobed; 
corolla usually more or less irregular, sometimes two-lipped, the 
upper lip of 2, and the lower of 3 lobes; stamens 4, or 2 that are 
perfect, epipetalous, a fifth stamen (staminode) sterile; ovary 
superior, two-celled or one-celled with 2 parietal placentae, ovules 
numerous, stigma two-lobed; fruit usually a capsule, some- 
times fleshy and indehiscent; seeds flattened, often winged; 
endosperm 0. 




FIG. 142. The bignonia family, Bignomaceae. A, flowering branch of 
trumpet vine, Tecoma radicans (after Le M ". and Dec.); B, sectional view of 
single flower in catalpa, Catalpa (after Baillon); C, a single flower of Tecoma 
(after BaiUon); D, floral diagram of Tecoma (after Le M. and Dec); E, floral 
formula for the family. 

This family includes many plants of value as ornamentals 
such as the trumpet vine, Tecoma radicans, a deciduous, woody 
vine, with pinnate leaves, and large scarlet or orange flowers, 
and the Jacaranda or Jack tree, Jacaranda ovalifolia, with its 
wonderful masses of blue flowers, often seen in Southern California 
and other subtropical and tropical areas. The catalpas are trees 
that are also highly ornamental and some of them, C. speciosa, 
produce valuable wood. These trees grow in fairly cool climates. 

THE BROOMRAPE FAMILY 

The Orobanchaceae are also known as the cancer-root family 
(Fig. 143) because the group includes plants that are mostly para- 
sitic on the roots of other plants. There arc 11 genera and more 
than 200 species of erect, simple or branched, yellowish, red, or 



228 



FLOWERS AND FLOWERING PLANT* 



almost colorless parasites in this family, with wide distribution in 
the northern hemisphere. The family has much in common 
with the Scrophulariaceae except the parasitism. 

Leaves often reduced to alternate, chlorophyll-less scales, 
plants often nearly leafless or with stems scaly only at the base; 
flowers usually perfect, zygomorphic, often crowded in terminal, 
bracted spikes, sometimes solitary; calyx four- to five-toothed or 
lobed or deeply cleft; corolla irregular, sympetalous, five-lobed, 
two-lipped; stamens 4, in 2 sets, (didynamous), on the tube of 
the corolla and alternate with the corolla lobes, staminode 




PARASITIC CAP 



FIG. 143. 'The broomrape family, Orobanchaccae. A, flowering habit of 
Orobanche americana, Ameri|an broomrape; H, single flower with the corolla 
removed; C, single flower complete; D, floral formula for the family (after 



sometimes present; ovary superior, one-celled, with 4 parietal 
placentae, ovules numerous, stigma t wo-lobed or discoid ; fruit a 
two-valved capsule, seeds numerous, small, endosperm fleshy. 
There are no particularly valuable species in this family, but 
some of them are of slight economic interest because of the fact 
that they parasitize certain cultivated plants. The whole 
group is of great scientific interest on account of the intense 
parasitism associated with their flowering-plant life history. 

THE ACANTHUS FAMILY 

This family, the Acanthaceae, include 175 or more genera and 
about 2,000 species of herbs and climbers (a few are shrubby) of 
wide distribution in the tropical and subtropical regions of the 



GENTIANS, PHLOXES, SNAPDRAGONS, AND MINTS 229 

world. The group is usually difficult for the beginning student of 
flowering plants because of the technical details that are utilized 
in the classification of the species. 

Leaves opposite, simple; flowers perfect, usually zygomorphic, 
often in conspicuously bracted spikes or glornerules; calyx four- 
to five-lobed or rarely reduced to a low ring; corolla sympetalous, 
four- to five-lobed, two-lipped, sometimes nearly regular; sta- 
mens 4, in 2 sets (didynamous), or 2, inserted on the corolla 
tube and alternate with its lobes; ovary superior, sessile, on a disk, 
two-celled, style simple or stigmas 2, ovules 1 to many in each 
cell ; fruit a capsule, usually elastically dehiscent ; seeds borne on 
curved projections or hooks, often covered with mucilage and 
spiral threads when wet; endosperm mostly lacking. 

Numerous species and varieties of this family are grown under 
glass for ornamental purposes. Certain thistle-like species of 
Acanthus, especially -4. mollis, and the beautiful foliage plant, 
Strobilanthus degerianus, are among the cultivated members of 
the group. 

THE BLADDERWORT FAMILY 

The members of the Lentibulariaceae are aquatic or marsh 
herbs, often submerged, or merely on moist soil, sometimes 
epiphytic. There are 4 or 5 genera and about 190 species of 
wide distribution. 

Leaves in basal rosettes, alternate on branching stems or 
reduced to scales, often dissected; flowers perfect, zygomorphic, 
on slender scapes which push the flowers above the water in aquatic 
forms; calyx two- to five-parted; corolla ^mpetalous, five-lobed, 
two-lipped, spurred at the back; stamens 2, inserted at the base of 
the corolla tube, 2 reduced stamens sometimes present; ovary 
superior, one-celled, ovules numerous, stigma sessile or style short; 
fruit a capsule opening by 2 to 4 valves; seeds rough or bristly; 
endosperm 0. 

The submerged stems in Utricularia are commonly finely 
branched, the leaves are dissected into filiform segments and the 
plants thickly supplied with tiny, flattish bladders that are 
contracted at the mouth. The plants are sometimes included 
in aquatic cultures in gardens and conservatories. 

ORDER LAMIALES, THE MINT ORDER 

We may refer to this order as the mints and their immediate 
kin, but the order includes the verbena family, Verbenaceae, as 



230 FLOWERS AND FLOWERING PLANTS 

well as the mint family, Labiatae. They are mostly herbs with 
opposite or whorled leaves and zygomorphic, often two-lipped 
flowers, stamens 2 to 4, the two-celled ovary is often deeply four- 
lobed and it commonly develops into 4 separate, bony nutlets. 
This order is higher than the Scr op hular idles, and it represents 
the terminus of this series of Dicotyledons. Both of these 
orders reflect many of the features that are regarded as indicative 
of a relatively high degree of development and hence they are 
accorded high positions in our arrangment. These features 
include an extreme reduction in the number of carpels, seeds, 
and stamens, the almost universal adoption of sympetaly, and 
a strikingly bizarre zygomorphy. 

THE VERBENA FAMILY 

The verbenas or the Verbenaceae are mostly herbs, but the 
family also includes numerous shrubs and trees grouped in 70 
genera and about 1,000 species of south temperate and tropical 
countries, with many genera and species in cultivation, some of 
them being highly prized ornamentals. 

Leaves opposite or whorled, sirqple or compound; flowers 
perfect, zygomorphic or rarely almost regular, often two-lipped; 
calyx four- to five-lobed or toothed, persistent; corolla sym- 
petalous, tubular, four- to five-lobed; stamens 4, or rarely 2, 
on the corolla; ovary superior, of 2 carpels or rarely four- to 
eight-celled, each cell with 1 ovule, style terminal, simple; fruit a 
drupe or berry, or dry and containing two to four nutlets; 
endosperm scanty or none. 

This family is separmed from the closely related Labiatae by 
the fact that the ovary here is seldom lobed, whereas in the latter 
the ovary is commonly deeply four-lobed around the style, and it 
is distinguished from the Boraginaceae by its zygomorphic flowers. 

There are many fine ornamentals among the verbenas, notably 
in the genus Verbena, with its many species and varieties of 
brightly flowered bedding plants, and the shrubby or climbing 
Lantana, particularly L. camara, and L. sellowiana. Teakwood 
comes from Tectona grandis, a member of this family. 

THE MINT FAMILY 

The mints and their closest kin are included in the family 
Labiatae, or Lamiaceae as it is sometimes written (Fig. 144). 
The former name reflects the bilabiate flower structure so common 
here, and the latter family name is from Lamium, one of the 



GENTIANS, PHLOXES, SNAPDRAGONS, AND MINTS , 231 

genera of the group, which also is from a word that calls atten- 
tion to the shape of the corolla. These plants are mostly aromatic 
herbs and shrubs (few trees) with a distribution through the 
world under a great variety of climatic and soil conditions, 
being especially abundant in the Mediterranean Basin, in the 
Oriental countries, and in mountain regions. There are about 160 
genera and 3,000 species now recognized. Many of them are 
cultivated for ornamental purposes and for their ethereal oils 
that are used in medicines, confections, and cosmetics. 




FIG. 144. The mint family, Labiatae. A, flowering stem and details of the 
flower of peppermint, Mentha pipenta (after Bentham); B, habit and flowers of 
a mint, Lamium ample xicaule (after Bentham); C, flowering stem and a single 
flower of mint, Stachya (after Bentham); D, floral diagram of Lamium (after 
Le M. and Dec.); E, floral formula for the family. 

Leaves opposite or whorled, simple, stems commonly quad- 
rangular; whole plant often very aromatic; flowers perfect, 
zygomorphic, rarely nearly regular, axillary or whorled, or in 
terminal spikes; calyx of 5 united sepals, five-toothed, five-cleft, 
regular or two-lipped; corolla sympetalous, five-lobed, typically 
two-lipped (bilabiate); stamens 4, in 2 sets (didynamous) or 
only 2, on the corolla tube; ovary superior, two-celled, each 
oarpel deeply two-lobed, 1 ovule in each lobe, style arising from 
the center of the four-lobed ovary, stigma two-lobed; fruit of 4 
more or less free, one-seeded bony nutlet/s; endosperm none. 

Among the popular, cultivated, ornamental, oil-producing, 
and drug mints are rosemary, Rosmarinus officinalis, sage, 
Salvia splendens, S. officinalis and S. azurea, lavender, Lavandula 
spica, thyme, Thymus vulgaris, peppermint, Mentha piperita (Fig. 
144 A), spearmint, M. spicata, horsemint, Monarda didyma, M. 
fistulosa^ etc. 



CHAPTER XVII 
BUTTERCUPS TO ASTERS 

We have now completed a general survey of one of the two 
great major series or superorders of Dicotyledons beginning with 
the Ranales, or buttercups, and ending with the Lamiales, or 
mints. Diagnoses of numerous families in the various orders 
of this line have served to indicate the nature of the plants 
involved, the general course of their development, and their 
relationships. We will now return to the Ranales and their 
kin to begin a similar treatment of the other major series of 
dicotyledonous orders and families. 

The members of this second superorder or group of orders are 
characterized by flowers in which the receptacle or axis is 
expanded into a disk, or deepened to form a more or less urn- 
shaped or cup-like structure bearing the perianth and stamens on 
its margin, or in the sympetalous families the stamens are com- 
monly epipetalous. There are two principal subdivisions of 
this series as in the other line. The first or lower group 
includes orders and families in which polypetaly, polycarpy, 
and actinomorphy are the rule, and the flower ranges from 
hypogyhy to epigyny. The second or higher group includes 
those in which sympetaly, oligocarpy, epigyny, and epipetalous 
stamens prevail, and in which a considerable degree of zygo- 
morphy has also developed. The rose order, Rosales, is the 
first order of this great series to become differentiated from the 
primitive Ranalian plexus. 

ORDER ROSALES, THE ROSE ORDER 

This is one of the largest orders of flowering plants, there 
being at least 15,000 species included in the various families of 
which it is composed. Among these are many plants of great 
value for agricultural and horticultural purposes. The flowers 
are, cyclic, and usually perfect, actinomorphic to zygomorphic, 
arid polypetalous, usually the perianth is pentamerous, the stamens 
indefinite in number and free, and the carpels few to many, 

232 



BUTTERCUPS TO ASTERS 



233 



separate or united, or sometimes inclosed within or becoming 
grown to (adnate) the inner surface of a discoid or deep, cup-like 
axis. The flowers often superficially resemble the flowers of 
the Ranales, especially those of the buttercup family, Ranuncu- 
laceae, from which they may be separated by means of the disk- 
like or cup-like axis or portion of axis which prevails in the 
Rosales. The two orders are evidently closely related. 

THE ROSE FAMILY 

The Rosaceae or rose family (Fig. 145) are a large group of trees, 
shrubs, and herbs, or climbers of very diverse habit and wide 
distribution in temperate regions. The family as here treated 




FIG. 145. The rose family, Rosaceae. A, flowering spray of rose, Roxa 
(after Kaillon); B, sectional view of a flower of strawberry, Fragana (after 
liaillon}; C, sectional view of a flower of cherry, Primus (after Baillori); D, sec- 
tional view of a flower of pear, Pyrus (after Daillari); E, floral diagram of straw- 
berry, Fracjaria (after Baillori); F, floral diagram of pear, Pyrus (after BaMon); 
(I, floral diagram of peach, Amygdalus (after Le M . and Dec.}; If, floral diagram 
of rose, Rosa (after Le M. and Dec.); /, floral formula for the perigynous Rosa- 
cuie, J , floral formula for the epigynous Rosacear, 

includes three subdivisions that are sometimes separated into 
different families, i.e. the roses proper or, in a restricted sense 
Rosaceae, the apples, Malaceae, and the plums, Drupaceae or 
Prunaceae. The bases for the recognition of these groups are 
found in certain differences which the axis, ovary, and fruits 
exhibit in the three subdivisions. We will include all of these 
in a single more or less heterogenous family which, when so 
constituted, embraces about 100 genera and 2,500 species. 



234 FLOWERS AND FLOWERING PLANTS 

Leaves usually alternate, simple or compound; flowers perfect, 
mostly actinomorphic, axis typically cup-shaped or urn-shaped, 
or sometimes a combination of a conical or dome-shaped cen- 
tral portion, surrounded at the base by a disk-like flange (as 
in strawberry, Fragaria); sepals 5; petals 5, separate, borne on 
the rim of the cup or urn or on the edge of the disk (Fragaria); 
stamens numerous, free, commonly borne in several cycles of 5 
on the rim of the axis, i.e. they are perigynous; carpels few to 
many to one, free or variously united, often united with the 
surrounding axis disk or tubular cup, styles free or connate, 
commonly as many as the carpels, ovules 2 or more in each 
carpel; fruit an achene, pome, drupe, or follicle, or an enlarged, 
hollow, fleshy torus or axis (hip), often mistakenly called "ber- 
ries" (see chapter on fruits); seeds with little or no endosperm. 

This cosmopolitan family is very rich in its contributions to 
the pleasure and welfare of mankind. It includes apples, pears 
and quinces, Mains, Pyrus, Cydonia, of hundreds of species and 
varieties in cultivation, plums, cherries, and prunes, Prunus, 
also in great number, apricots, peaches, almonds and other 
" stone fruits,' 7 Primus, Amygdalus, etc., strawberries, Fragaria, 
blackberries, raspberries, dewberries, loganberries, Rubus, and 
hosts of ornamental garden favorites and conservatory plants. 
Among the latter may be mentioned the vast and varied group 
of roses, Rosa, of which thousands have been described, the 
spiraeas and bridal wreaths, Spiraea, mountain ash, Sorbus, 
hawthorns, Crataegus, and scores of other herbs, shrubs, trees, and 
vines that are cultivated for their beauty of form, foliage, or flower. 

THE SENNA FAMILY 

The sennas as here understood are included in the family 
Caesalpiniaceae, a group of about 90 genera and 1,000 species of 
trees, shrubs, and a few herbs, mainly found in tropical regions. 

Leaves mostly compound, pinnate or bipinnate, rarely simple 
or one-foliate; flowers perfect or rarely diclinous in more or less 
clustered, showy, racemose inflorescences, zygomorphic or nearly 
actinomorphic in some forms; sepals 5, free or the upper pair 
united; petals 5 or fewer, the upper one inclosed by the lateral 
petals; stamens 10 or less, filaments distinct or variously connate; 
ovary superior or in base of shallow cup, one-celled, ovules 
numerous; fruit a legume, dehiscent into 2 valves; seeds with or 
without endosperm. 



BUTTERCUPS TO ASTERS 235 

The sennas have certain features in common with the beans, 
Leguminosae, but the flowers are only slightly zygomorphic. 
Many important timber trees of the Tropics belong here such as 
the purple heartwood, Copaifera pubiflora, of British Guiana, 
West Indian Locust, Hymenaea courbaril, and the tamarind, 
Tamarindus indica. The honeylocust, Gleditsia triacanthos, is 
an important tree of temperate North America. There are 
also many ornamental trees and shrubs in the family including 
the redbud, Cercis canadcnsis, various species of senna, Cassia, 
and the poinciana, especially Poinciana pulcherrima. The 
curious Algaroba or St. John's bread, Ceratonia siliqua, also 
belongs in this family. This is a large tree of the Eastern 
Mediterranean countries that produces large, red pods that 
are edible. 

THE MIMOSA FAMILY 

This is the Mimosaceae, sometimes known also as the acacia 
family. They are almost exclusively trees or shrubs of about 30 
genera and 1,400 species widely distributed in tropical and sub- 
tropical regions. 

Leaves alternate, usually bipinnate, rarely simply pinnate; 
flowers perfect, small, in heads, racemes, or spikes, actinomorphic; 
sepals 3 to 6; corolla 3 to 6, petals separate or united into a short 
tube; stamens equal in number to sepals or more numerous, free 
or monadelphous; ovary superior, one-celled, ovules numerous; 
fruit a legume; seeds with scanty or endosperm. 

One of the more striking genera of this family is Acacia, of 
which about 450 species have been described, many of which are 
cultured out of doors in tropical and subtropical countries. 
Gum Arabic comes from Acacia Senegal, of tropical Africa. The 
so-called sensitive plants of the genera Mimosa and Morongia 
are also included in this family. There are about 300 species of 
Mimosa in tropical America, among which the best known one is 
Mimosa pudica, so often used to demonstrate the sensitive 
nature of the leaves and leaflets. The sensitive brier, Morongia 
uncinata, is almost as sensitive as Mimosa, and this plant is 
found well north in the American prairies. 

THE BEAN FAMILY 

The technical designation for this family is rather varied, but 
either Leguminosae or Papilionaceae is commonly used as the 
family name for the group. The former term is in recognition 



236 



FLOWERS AND FLOWERING PLANTS 



of the common fruit of the family, and the latter is from a fancied 
resemblance of the flower to a butterfly, i. e. the flower is papil- 
ionaceous or " butterfly-like." This is an enormous, cosmopolitan 
family including about 400 genera and more than 5,000 species 
of herbs, shrubs, trees, and many climbing plants, found under 
extremely varied soil and climatic conditions, but most abundant 
in temperate and warm climates (Fig. 146). 

Leaves alternate, mostly compound, pinnate or digitate, or 
rarely simple; flowers mostly perfect, zygomorphic, in spikes, 
heads, racemes, or panicles; axis more or less tubular; sepals 5; 




Fia. 146. The bean family, Legumino^ac. A, pea, Pisum (after Baillori); 
B, front view of the papilionaceous flowor of Pisum (after Baillori), C, corolla of 
Pisum dissected; D, diadelphous stamens of Pisum (after Baillori); E, floral dia- 
gram of sweet pea, Lathyrus (after Le M. and Dec.); F, floral formula for the 
generalized family; G, flower of clover, Tnfolium (after BaUlon); H, flawer of 
Cassia (after Baillori); /, sectional view of flower of Cassia (after Baillon); J 
floral formula for the Caesalpiniaceac; K, Mimosa, flower heads and leaves 
(after Le M. and Dec.). 

petals 5, (2 plus 2 plus 1) free or somewhat united, the upper one 
exterior, commonly larger or broader than the rest and forming 
the "standard" or "banner," the 2 lateral petals, i.e. "wings," 
smaller and alike and more or less parallel with each other, the 
other 2 petals are interior, or lower, or in front and more or less 
united by their lower edges to form the "keel"; stamens usually 
10, (9 and 1) inserted on the rim of the axis with the petals, free 
or commonly monadelphous or diadelphous; ovary superior, 
one-celled or 2-celled by intrusion of sutures, ovules 1 to many; 
fruit a legume; seeds usually without endosperm. 



BUTTERCUPS TO ASTERS 237 

This family includes a great many species and varieties that 
are of major economic importance to man. They contribute 
products of great variety from foods and flowers to drugs and 
dyes. Peas, Pisum sattvum, and beans, Phaseolus vulgaris, of 
numerous kinds are among the most important foods of the world. 
Peanuts, Arachis hypogaea, and lentils, Lens esculenta, are addi- 
tional bean or pea-like plants, the seeds of which are valuable as 
food. Forage plants like lucerne or alfalfa, Medicago sativa, and 
clover, Trifolium pratense and T. arvense, have almost inestimable 
value as food for animals and as means of maintaining proper 
soil fertility for a varied agriculture. Scores of very excellent 
ornamentals are also found here, such as sweet peas, Lathyrus 
odoratus, Chinese wisteria, Wisteria sinensis, locust, Robinia 
hispida, and Japanese pagodatree, Sophora japonica. The log- 
wood of Central America, Haematoxylon campechianum, is the 
source of the dye, haernatoxylon, so useful in microscopic tech- 
nique. Numerous drug plants, including liquorice, Glycyrrhiza 
glabra, and many stock-poisoning plants such as loco weed, 
Aragallus lambertii, are also members of this great natural alliance. 

THE SAXIFRAGE FAMILY 

The Saxifragaceae, or saxifrage family are given this name from 
the genus Saxifraga which means "rock-breaking" with the sup- 
position that because certain species of the family are regularly 
found growing on rocks the group is composed of " rock-breakers." 
They are mostly herbs with alternate leaves, often more or less 
succulent and they are arranged in 75 to 100 genera and 1,000 
to 1,100 species of wide distribution in temperate and cold regions 
(Fig. 147). 

Leaves alternate, rarely opposite; flowers perfect or diclinous, 
actinomorphic, commonly perigynous or rarely more or lesy 
epigynous; sepals 4 to 5; petals 4 to 5 or 0; stamens 4 to 5 or 
8 to 10, inserted with the petals on the rim of the axis, i.e., 
perigynous; carpels 1 to 3, usually 2, free or united and imbedded 
in the more or less tubular axis or definitely inferior, styles 
usually free, ovules numerous; fruit a capsule or berry; seeds with 
abundant endosperm. 

This family is evidently closely related to the Rosaceae although 
it is placed elsewhere by so~rne authors. The number of sta- 
mens and pistils has been reduced and definitized as perhaps 
the most prominent advance as compared with the Rosaceae. 



238 



FLOWERS AND FLOWERING PLANTS 



The relationship to the following family, Hydrangeaceae, is also 
close, as it is to the gooseberry family, Grossulariaceae. 

Several species of Saxifraga are cultivated for ornamental 
purposes, but species of Astilbe, especially A. japonica, are 
perhaps better known to flower lovers for their panicles of small 
white or pink flowers. 




FIG. 147. The saxifrage family, Saxifragaceac. A, saxifrage, Saxifraga 
cernua (after Kerncr); B, section of single flower of Saxifraga (after Bailloti); 
C, front view of a flower of initerwort, MitcUa (after BaiUoti); D, sectional view of 
another species of Saxifraoa (after Le M. and Dec.}; E, floral diagram of Saxifraya 
(after Baillori); F, another floral diagram of Saxifraga (after Le M. and Dec ); 
G, floral formula for the family. 

THE HYDRANGEA FAMILY 

This family, the Hydrangeaceae, is much like the preceding 
family, but the hydrangeas are mostly shrubs and trees with 
opposite leaves. There are 15 or more genera and about 85 
species included in the family and these are found in north 
temperate and tropical regions (Fig. 148). 

Leaves opposite, simple; flowers usually perfect, small, or the 
exterior ones in the cluster may be sterile and showy, in corym- 
bose clusters; the marginal flowers sometimes apetalous, but 
then with enlarged and conspicuous calyx with spreading lobes; 
calyx of 4 to 10, usually 4 to 5 sepals, inserted on the rim of the 
cup-like or tubular axis; petals 4 to 10, usually 4 or 5, on the rim 
of axis; stamens five to many, on the rim of the axis, free or 
slightly connate at the base; carpels 2 to 5 (2 to 10), united or 
tips more or less, free, more or less overgrown by the cup-like 
axis, i.e., partly or wholly inferior; ovules few or numerous; 
fruit a capsule, often strongly ribbed; seeds numerous, small; 
endosperm abundant. 



BUTTERCUPS TO ASTERS 



239 



There are many beautiful flowering ornamentals included in 
this family, among which are the numerous species of Hydrangea 
and Deutzia, of which there are several that are cultivated 
mainly for their beautiful clusters of showy flowers. The mock 
orange, i.e. various species of Philadelphus, is also included here. 




FIQ. 148. The hydrangea family, Hydranyeaceae. A, flowering twig of 
Philadelphus (after Le M. and Dec.); B, sectional view of a flower in Philadelphus 
(after Baillori); C, floral diagram of Ph^ladelph^ls (after Baillon); D, floral diagram 
of Hydrangea (after Le M. and Dec.); E, floral formula for the family ; F, flowering 
branch of another species of Philadelphus (after Baillon) . 

THE GOOSEBERRY FAMILY 

This group, the Grossulariaceae y is sometimes included, along 
with the Hydrangeaceae, in the Saxifragaceae. It is represented 




FIG. 149. The gooseberry family, Grossulariaceac. A, leaves and flowers of 
black currant, Ribes nigrum (after Baillon); B, section of a single flower of the 
same (after Baillon); C, section of a single flower of Ribes rubrum (after Kerner); 
D, floral diagram of Ribes (after Baillon); E, floral formula for the family. 

by the single genus Ribes which inchides the gooseberries and cur- 
rants (Fig. 149). Some authors split the species into two genera, 
Ribes, the currants, and Grossularia, the gooseberries. The 
latter, i.e., the gooseberries, are spiny shrubs with few-flowered 



240 



FLOWERS AND FLOWERING PLANTS 



racemes. The former, i.e. the currants, are smooth shrubs with 
many-flowered racemes. There are about 60 species of shrubs in 
the one or two genera and they are mainly found in the north 
temperate hemisphere, and in South Africa and the Andes. 

Leaves fasciculate, simple, usually lobed; flowers perfect or 
often unisexual; calyx of 4 to 5 sepals on the rim of the tubular 
axis, often colored; petals 4 to 5, inserted on the rim of the axis, 
small or scale-like ; stamens 4 to 5, alternate with petals on rim of 
axis; ovary one-celled, with 2 parietal placentae, wholly imbedded 
in the axis, i.e. inferior, styles 2, free or connate, with undivided 
stigmas, ovules numerous or few ; fruit a pulpy berry with persistent 
calyx on its summit, seeds numerous or few, with endosperm. 

There are many cultivated species and varieties of currants 
and gooseberries that furnish delightful edible berries. Certain 
ones are also used as ornamentals, as is the case of the golden 
currant, Ribes aureum, which is grown for its yellow, spicy flowers. 

THE WITCHHAZEL FAMILY 

The Hamamelidaceae, commonly known as the witchhazels, 
include about 20 genera and 50 species of shrubs and trees that 

are widely distributed in subtropical 
and the warmer parts of temperate 
regions in North America, South 
Africa and Asia (Fig. 150). 

Leaves alternate, rarely opposite, 
deciduous or evergreen, simple; flow- 
ers small, perfect or diclinous, acti- 
nomorphic or zygomorphic ; axis more 
or less tubular, bearing 4 to 5 sepals; 
petals 4 to 5, rarely 0, inserted on the 
rim of the axis, along with four to 
many stamens; ovary inferior, i.e. 
FIG. 150. The witchhazel imbedded in the axis, bicarpellary, 

family, Hamamelidaceae. A carpe l s o ft e n free at tips, Styles free, 
portion of the inflorescence of , 11 

witchhazel, Hamamehs, show- ovules 1 or several in each carpel; 

ing flowers and a young fruit; f ru ft a more or l ess WO ody Capsule; 
B, vertical section of a flower; . _ t . . . 

c, mature fruit; D, vertical seeds forcibly discharged when npe 
section of unripe fruit (all after | n Hamamelis; endosperm thin. 

The American witchhazel is Ham- 
amelis virginiana, a shrub or low tree of eastern United States. 
This plant is interesting because its flowers do not open until 




BUTTERCUPS TO ASTERS 241 

the leaves have fallen in the autumn. It is sometimes planted as 
an ornamental. This species furnishes the witchhazel extract of 
the pharmacist. The sweetgum, Liquidambar styraciflua, is an 
important timbertree of southeastern United States, and is the 
source of styrax. 

THE SYCAMORE FAMILY 

The sycamores or plane trees belong to the family Platanaceae, 
(Fig. 151) a small group of five or six species of trees included in 
one genus widely scattered in the north temperate and tropical 
/ones from Europe to India, and from North America south into 
Central America. 




Fi. 161 The sycamore family, Platanaceae. A, twig and leaf of American 
sycamore, Platanuf* occidental^; B, heads of fruits of same, C, twig, buds and base 
of petiole of same (after .\fathews); D, floral formula for the family. 

Leaves alternate, simple, palmately veined and lobed, the 
expanded petiole base covering the young bud, young leaves 
rusty tomentose; bark of the branches often exfoliating in thin, 
irregular plates; flowers monoecious, arranged in dense, globular, 
pedunculate heads; perianth inconspicuous but represented by 
3 to 8 more or less uncertain parts; stamens 3 to 8; pistils 3 to 8, 
each one-celled; the pistillate head enlarges in fruit, but the 
carpels remain free and each becomes a narrowly obconical, 
one-seeded nutlet with a tuft of long hairs at the base; endosperm 
thin. 

The common American sycamore is Platanus occidentalis, 
and the European and Asiatic sycamore is P. orientalis. The 
London plane, P. acerifolia, is planted very commonly in east- 
ern United States on streets and in parks. Several varieties are 
known in cultivation. The nature of the fruiting heads of the 
sycamores has given rise to the common name, button-ball tree, 
which one occasionally hears. The name sycamore is also used 



242 



FLOWERS AND FLOWERING PLANTS 



for a certain fig, Ficus sycomorus. The quarter-sawed wood of 
the sycamore is very beautiful. 

THE STONECROP FAMILY 

The stonecrops, constituting the family Crassulaceae, are 
mostly fleshy or succulent herbs or undershrubs arranged in 
about 20 genera and 900 species widely distributed in the warm, 
dry regions of both hemispheres (Fig. 152). 

Leaves opposite or alternate, simple or pinnate, often extremely 
succulent; flowers perfect, actinomorphic, usually small and 
borne in cymes; sepals 4 to 5, free, borne on a tubular receptacle; 




FIG. 152. The storiecrop family, Crassulaceae. A, flowering branch of 
live-for-ever, Sedum (after Le M. and Dec.); B, single flower of Sedum (after 
Baillon); C, floral diagram of Sedum (after Baillori); D, floral diagram of Sedum 
(after Le M. and Dec ); E, floral formula for the family; F, flowering stem and 
flower details of Sedum tclcphium (after Bentham). 

petals 4 to 5 or 0, free or somewhat united; stamens as many 
as or twice as many as the petals, free; carpels superior or in 
the bottom of the receptacle, same number as petals, free or 
united at the base, each one-celled, ovules usually numerous; 
fruit a one-celled, dehiscent follicle; seeds minute, with fleshy 
endosperm. 

This family includes many species and varieties that are widely 
used for borders in landscape decoration and in rock gradens and 
also grown as potted plants in conservatories for their bright 
yellow flowers. The genus Sedum includes many species known 
as " live-f or-evers " and among these S. spectabile, prized for its 
fine clusters of pink flowers. The "houseleek" or "hen and 
chickens," Sempervivum tectorum, or Echeveria secunda, are 
popular as border plants. Very beautiful flower-bed effects 
are worked out by using these plants with foliage plants to 
construct various designs. 



CHAPTER XVIII 
THE MYRTLES, STARFLOWERS, AND CACTUSES 

This group of orders is regarded as a lateral development from 
the general plexus represented by the Rosales. The Myrtales 
constitutes the main axis of this lateral phyletic line and this 
order is regarded as having given rise to two branches including 
the Loasales and the Cactales. 

The series includes trees, shrubs, and herbs mostly with oppo- 
vsite, simple, often glandular leaves, and actinomorphic, epigy- 
nous flowers. The modification of the perigynous and epigynous 
types of flowers of the Rosales in this group of orders is such as 
to give them a characteristically inferior ovary. A high degree 
of succulence, leaf reduction, and spininess is reached in the 
Cactales. 

ORDER MYRTALES, THE MYRTLE ORDER 

This, the myrtle order, includes families of woody and herba- 
ceous plants in which the flowers are usually regular and perfect ; 
the pistil is typically inferior and syncarpous, placentae axile or 
apical, style one to many, stamens commonly numerous; leaves 
commonly opposite and simple. 

THE MYRTLE FAMILY 

The Myrtaceae, or myrtle family, include trees and shrubs 
with opposite (rarely alternate) leaves that are often glandular 
and aromatic (Fig. 153). There are about 72 genera and 3,000 
species in the family, and these are largely confined to the tropics 
and Australia. 

The leaves are usually evergreen, thick, and glandular dotted ; 
flowers actinomorphic, perfect or rarely polygamous, epigynous; 
sepals 4 to 5, on the rim of the axis, often persistent on the 
fruit; petals 4 to 5 or 0, also on the axis, imbricated: stamens 
numerous, rarely few, inserted on the margin of the axis in 
fascicles opposite the petals, free or connate below; ovary 
inferior, one- to many-celled, with one to many ovules in each 

243 



244 



FLOWERS AND FLOWERING PLANTS 



cell, placentae axile, rarely parietal, style simple; fruit a berry, 
capsule, or nut; seeds few to many; endosperm or scanty. 

Thfs family includes numerous plants of high economic value 
on account of the edible fruits and aromatic oils that they pro- 
duce, in addition to many species that are of value as ornamentals. 
The fruit of*guava, produced by certain species of Psidium, 
especially P. cattleianum and JP. guajava, is a pulpy berry with 
many seeds and acid juice, used in jelly manufacture. The 
"cloves" of commerce are the dried, unopened flower buds of 
Eugenia aromatica, a low tree native to the Moluccas, but also 
widely cultivated in tropical lands. Allspice is the dried, unripe 




FIG. 153. The myrtle family, Myrtaccac. A, flowering twig of myrtle, 
Myrtus (after Le M. and Dec.); B, vertical section of a flower of Myrtus (after 
Baillon); C, flowers of clove, Eugenia (after Warming); Z), vertical section of a 
flower of clove (after Warming); E, floral diagram of myrtle, Myrtus (after 
Baillon); F, floral diagram of myrtle, Myrtus (after Le M.*o&d Dec.); G, floral 
formula for the family. 



berry of the closely i;dated Pimenta officinalis of the West Indies 
and Central Americ^.Jj , 

The genus Eucalyptus is a noteworthy member 'Of this family. 
Certain species of these Australian !, and Malayan trees reach 
heights of 400 to 500 feet, and the leaves contribute a series of 
valuable, volatile oils, gums, and resins. The blue gum, E. 
globulus, and the red gum, E^faafrata, are grown in California. 

The classic myrtle is Myttus communis, an evergreen shrub 
with aromatic shining leaves, native to the Mediterranean Basin 
and Western Asia. 

THE POMEGRANATE FAMILY 

This interesting family, Punicaceae, includes one genus only 
and two species of low trees or shrubs native from the Balkan 
countries to the Himalayas, but the pomegranate has been 



THE MYRTLES, STARFLOWERS, AND CACTUSES 245 



widely cultivated in tropical and subtropical regions from very 
early times (Fig. 154). 

Leaves opposite or whorled, simple, not glandular; branches 
often spiny dipped; flowers perfect, one to few on the tips of 
axillary shoots; receptacle (ovary) and calyx colored, more or 
less leathery, sepals thick, 5 to 7, on the margin of tUfc receptacle ; 
petals 5 to 7, imbricate, crumpled, alternate with the sepals on 
the edge of the axis; stamens numerous, in a fringe on the inner 
surface of the axis opposite the petals; ovary inferior, often 




FIG. 154. -The pomegranate family, Punicaceae. A, flowers and loaves of 
pomegranate, Pumca granatum (after Baillori); B, vertical section of a flower of 
Pumcci (after Baille/i); C, floral diagram of Pumca (after Le M. and Dec.); 7), 
floral formula fcjtffe family. 

colored, of 4 to 15 united carpels, cells superposed, the lower with 
axile and the upper with parietal placenl^w style simple; fruit a 
thick-skinned or leathery berry crowned^JjRhe sepals, containing 
numerous seeds surrounded by bright red, juicy pulp; endosperm 
none. 

The pomegranate of commerce is the fruit of Punica granatum, 
a low tree widely cultivated jij . warm countries. In ancient 
times the best pomegranates wre'jgroduced in Carthage, and 
so they came to be known as "Puni chappies " and later as Punica. 
Many cultivated varieties of pomegranates are recognized, among 
which is a dwarf, double-flowered form sometimes seen in green- 
houses and florist's shops. 

THE MANGROVE FAMILY 

The mangrove family, Rhizophoraceae, includes mostly trop- 
ical and subtropical trees and shrubs of wide distribution along 



246 



FLOWERS AND FLOWERING PLANTS 



maritime shores. The family includes 15 genera and about 50 
species (Fig. 155). 

Leaves opposite, evergreen, commonly leathery; flowers 
perfect, actinornorphic, epigynous, in axillary clusters; sepals 
4 to 5 or more, valvate, persistent, on the edge of the axis; petals 
4 to 5, sml^^notched or fringed, on edge of the axis; stamens 
equal in number to, or more numerous than the petals, opposite 
the petals on the edge of the axis ; ovary inferior, two- to six-celled 
or rarely one-celled, style simple, ovules 2 or more; fruit a berry, 
or a dry or somewhat fleshy capsule ; seeds 1 or more in each cell ; 
endosperm fleshy when present. 




FIG. 155. The mangrove family, Rhizophoraceae. A, leafy twig and young 
fruit of mangrove, Rhizophora (after Baillori); B, single flower of Rhizophora 
(aftpf Baillon); C, floral diagram of Rhizophora (after Baillon); D, floral formula 
for the family. 

The mangroves con|ponly form a fringe of tangled shrubs 
along the shoreline o^the sea, especially on muddy coasts and 
estuaries. The seed germinates within the ovary on the tree 
and the seedling sometimes reaches a length of a foot or more 
before it falls away from the tree into the mud or shallow water. 
This is an illustration of vivipary, a phenomenon not at all 
common among plants. The young plant may become anchored 
at once or it may float away only to become established at some 
' distance. They may serve to build up or extend the shoreline in 
such places. 

THE EVENING PRIMROSE FAMILY 

The Onagraceae, or evening primrose family, are a conspicuous 
group of annuals and perennials that are mostly herbaceous or 
rarely woody (Fig. 156). They are largely native to the tern- 



THE MYRTLES, STARFLOWERS, AND CACTUSES 247 

perate and warm portions of the western hemisphere, but with 
certain interesting species in Europe and Africa. The family 
includes about 36 genera and 470 species. 

Leaves opposite or alternate, usually simple; flowers perfect, 
actinomorphic or rarely zygomorphic, epigynejps, axillary, 
spicate or racemose; calyx "adnate to the ovary4Por the ovary 
imbedded in the axis, i.e. inferior; sepals 2, 4, or 5, commonly 4, 
attached to the rim of the axis which is often prolonged beyond 
the ovary to form a slender tube; petals 2, 4, or 5, commonly 4, 
free, alternate with the sepals on the rim of the receptacle; 
stamens as many or twice as many as the petals, free, inserted on 




FIG. 156. The evening primrose family, Onagraceae. A, flowering stem of 
Oenothera (after Baillori); B, vertical section of a single flower of Oenothera 
(after Baillori); C, flowering stem of Fuchsia (aftef^Le M. and Dec.); D, vertical 
section of a flower of Fuchsia (after Baillori); E, floral diagram of willowherb, 
Epilobium (after Le M. and Dec.); F, floral diagram of Oenothera (after Baillori); 
G, floral formula for the family. 

the summit of the axis ; ovary two- to six-celled, commonly four- 
celled, ovules one to many, on axile placentae, style 1, stigma 
simple, or two- to f our-lobed or divided ; fruit a capsule or nut 
with one to many seeds; endosperm scanty or 0. The members 
of the family are often easily recognized on account of the tetram- 
erous flowers with inferior ovary. Students should bear in 
mind that this family is very different from the true primroses, 
which belong to the Primulaceae. 

Many of these plants are grown for ornamental purposes and 
numerous wild species are noteworthy for the remarkable 



248 



FLOWERS AND FLOWERING PLANTS 



beauty of their flowers. The species of Fuchsia, often called 
" fuchsia" are among the most commonly cultivated members 
of the group. These herbs, shrubs, or low trees are known for 
th.e beautiful purple, red or white, usually drooping flowers. 
The firewdlft Epilobium angustifolium, is often a conspicuous 
invader soo^pter forest fires. ^ The water-chestnut, Trapa natans, 
a curious aquatic, also belongs here. 



THE LOOSESTRIFE FAMILY 

The Lythraceae is a family of 23 genera and about 450 species of 
herbs, shrubs, and trees of very wide distribution, but they appear 
to be most abundant in tropical America (Fig. 157). Annual and 
perennial species of the group are more numerous in temperate 

regions, but the woody forms are 
more often seen in warm climates. 

Leaves opposite or verticillate, 
simple, entire; branches often four- 
angled; flowers perfect, usually 
actinomorphic, perigynous, soli- 
tary or in panicles or cymes; sepals 
4 to 5 or more, inserted on the rim 
of the axis in which the pistil is 
inclosed; petals 4 to 6, free or 0, 
inserted on the rim or somewhat 
beiow the rim of the tubular recep- 
tacle; stamens 4 to 8 or more, free, 
inserted on the axis, below the 
petals, filaments variable in length ; 
superior or more or less sur- 




QC6 6 S 48 P (0> 



FIQ. 157. The loosestrife family, 
Lythraceae. A, flowering and fruit- 
ing branch of loosestrife, Lythrum 
alatum (after Mathews); B, floral 

diagram of Lythrum (after Le M. rounded by the tubular receptacle 
and Dec.); C, floral formula for the bearing the perianth, two- to six- 

famil y- 11 j i i n 

celled, ovules many in each cell, on 

axile placentae, style simple; fruit a capsule; seeds numerous; 
endosperm 0. 

Certain members of this family produce important supplies of 
timber, as in Lagerstroemia flos-reginae, of India, and rose wood, 
Physocalymma scaberrimwn, of Brazil. The red dye, henna, is 
prepared from Lawsonia inermis, of tropical Asia. The cigar- 
flower, Cuphea platycentra, is a low shrub that is cultivated in 
greenhouses and as a bedding plant for its odd flowers. 



THE MYRTLES, STARFLOWERS, AND CACTUSES 249 

ORDER LOASALES, THE STARFLOWER ORDER 

The plants included in this order usually produce actino- 
morphic, perfect, or diclinous, mostly epigynous flowers in which 
the pistil is commonly tricarpellary but one-celled, the placentae 
are parietal and the stamens are indefinite in number. The 
leaves are alternate, simple, but often much lobed or divided. 

THE LOASA FAMILY 

The Loasaceae are sometimes known as the starflower family. 
They are mostly herbs, sometimes climbing, with a few woody 
species to be found in the Tropics and they are grouped into 13 
genera and about 250 species. They are native mostly in the 
tropical and temperate portions of the Americas. The chief 
center of distribution of the family appears to be Chile. 

Leaves alternate or opposite, entire, or variously lobed or cut, 
often bearing hooked, barbed, or stinging hairs; flowers perfect, 
actinomorphic, epigynous; receptacle, more or less tubular, 
bearing the 5 (or 4 to 7) free sepals and the $ (or 4 to 7) free petals 
on the rim; stamens 5 to 10 or more or indefinite, free or collected 
in groups on the receptacle opposite the petals; ovary inferior, 
carpels 3 to 7, each with many ovules on parietal placentae, 
usually one-celled, style entire or two- to three-parted; fruit a 
many-seeded capsule; seeds with or without endosperm. 

There are a few showy ornamentals included in this family, 
such as Loasa vulcania, of South America, and certain species of 
Mentzelia in western North America. 

& 
THE BEGONIA FAMILY 

The Begoniaceae, commonly known as the begonia family 
(Fig. 158) include 5 genera and about 400 species of widely 
distributed tropical, mostly succulent herbs or undershrubs. 
All but a very few of the species are included in the large genus 
Begonia, many of which are climbers, and many others are creep- 
ing or acaulescent. 

Leaves alternate, simple, often oblique or asymmetrical, 
stalked and succulent, margin entire, lobed or divided, often 
large and beautifully variegated; flowers mostly actinomorphic, 
but often zygomorphic, monoecious, showy, mostlj in axillary 
clusters; the male flowers have 2 opposite sepals, and 2 to 5 or 
petals inserted on the rim of the axis at the top of the ovary; 
stamens numerous, free or connate; the female flowers have a 



250 FLOWERS AND FLOWERING PLANTS 

perianth about the same as male flowers; ovary inferior, two- to 
four-celled, commonly tricarpellary, and often three-angled or 
three-winged, styles 2 to 5, commonly 3, with oddly bent or 
twisted fleshy stigmas; ovules numerous, on axile placentae; 
fruit a winged or angular capsule or berry with many fine seeds, 
with little or no endosperm. 

Scores of species and varieties of Begonia are grown as glass- 
house ornamentals and houseplants, and many are cultivated 
out of doors in warm countries. They are found in greatest 
number and luxuriance in the damp shady forests of Brazil and 




Fia. 158. The begonia family, Begomaceae. A, leaves and flowers of begonia, 
Begonia (after Le M. and Dec.}; B, floral formula for the family. 

the Andes. They are also numerous in the Himalayan rain 
forests and in the Malay Archipelago. The Rex type, Begonia 
rex, is unusually rich in foliage forms, and the floriferous type, 
represented by the B. semperflorens group, is rich in flower forms. 
Sometimes certain varieties of B. rex are known as " beef steak 
geraniums.' 1 

THE PUMPKIN FAMILY 

This large family, the Cucurbitaceae, includes a great variety 
of useful * plants such as watermelons, pumpkins, squashes, 
cucumbers, cantaloupes, gourds, etc. (Fig. 159). They are mostly 
annual or perennial, weak-stemmed, tendril-climbing herbs, or 
more rarely somewhat woody, with watery juice. There are 
about 100 genera and 800 species in the family and these are 



THE MYRTLES, STARFLOWERS, AND CACTUSES 251 

mainly tropical and subtropical in distribution, with a few species 
extending into temperate climates. 

Leaves alternate, broad, usually simple, but often deeply 
lobed or divided, sometimes compound, tendrils lateral, spirally 
coiled; flowers monoscious or dioecious, rarely perfect, actino- 
morphic; male flower with 1 to 5, mostly 3 stamens, inserted on 
the rim of the cup-shaped or tubular axis with 3 to 5 narrow sepals 
and a similar number of free or united petals; ovary in female 
flower inferior, mostly tricarpellary, with three parietal placentae, 




FIG. 159. The pumpkin family, Cucurbitaceae, A, flowering branch of 
muskmelon, Cucumis melo (after Baillori); B, single flower of watermelon, Citrul- 
lus vulgaris (after Baillori); C, flower of cucumber, Cucumis sativus (after Baillori); 
D, vertical section of a female flower of cucumber (after Le M. and Dec.); E, 
vertical section of a male flower of Citrullus (after Baillori); F, female flower 
(with perianth removed) of pumpkin, Cucurbita pepo (after BaiUori); <7, vertical 
section of male flower of pumpkin (after Baillori); H, floral diagram of male- 
flower (after Le M. and Dec.); /, floral diagram of female flower (after Le M. 
and Dec.); J, floral formula for the family. 

receptacle often prolonged beyond the ovary, ovules numerous, 
styje simple or with 3, free style branches; fruit a bladdery pod 
or a* fleshj?' berry-Hke structure with a hard rind and pulpy, 
seedy interior, a pepo. 

Numerous species and varieties of cucurbits are grown for 
their edible fruits and a few are cultivated for their ornamental 
values. The common pumpkin is Cucurbita pepo, with many 
varieties, including vegetable marrow and crookneck squashes. 
Muskmelons, cantaloupes, etc., are forms of Cucumis melo, 



252 



FLOWERS AND FLOWERING PLANTS 



citron and watermelons are from Citrullus vulgaris, and the 
cucumber is Cucumis sativus. The balsam apple, Momordica 
balsamina, is grown for its yellow fruit and crimson seeds. The 
dried, fibrous, bag-like interior of the fruit of the vegetable 
sponge, Luffa cylindrica, is used as a sponge or dishcloth. 

ORDER CACTALES, THE CACTUS ORDER 

These are succulent, or woody, often very spiny plants of 
desert and arid regions, with numerous sepals, petals, and 
stamens. The flowers are mostly actinomorphic, epigynous, 
and they are often very showy. 

THE CACTUS FAMILY 

The Cactuses, included in the natural family Cactaceae, are 
perennial herbs, shrubs, or trees of diverse habit (Fig. 160). 




Fio. 160. The cactus family, Cactaceae. A, flowering branch of prickly 
pear, Opuntia (after Mathews); B, vertical section of cactus flower (after Baillori}; 
C, floral diagram of Opuntia (after Le M. and Dec.); D, floral formula for the 
family. 

They are often quite leafless and very spiny (numerous spineless 
ones are known) and are mostly native to the warmer regions of 
America. More than 1,200 species in about 120 genera have 
been described. 

The fleshy, leafless stems are often flat, jointed, and green and 
so are mistaken for leaves ; when true leaves are present they are 
usually small and succulent and they soon fall; in many erect 
species the stems are cylindrical, fluted, and much branched; 
flowers perfect, usually actinomorphic, epigynous, usually 



THE MYRTLES, STARFLOWERS, AND CACTUSES 253 

solitary, often large and showy; calyx often petaloid, of many 
sepals on the margin of the receptacle, along with many brightly 
colored petals in several series; stamens numerous, indefinite, 
mostly free and inserted at the base of the petals; ovary 
inferior, one-celled, with 3 or more many-ovuled, parietal 
placentae; style 1, stigma two- to many-lobed; fruit a berry, 
juicy, often spiny and edible, many-seeded; endosperm 0. 

The Cactuses are peculiarly subtropical American in their 
modern distribution, but they have been naturalized in many 
other warm countries. They are of little economic value but 
are of great scientific interest, and many of them are grown in 
desert gardens and greenhouses. The " night blooming Cereus" 
is a cactus, Cereus triangularis. The Christmas cactus is Zygo- 
cactus truncatus. The tree cactus or giant Sahuaro of south- 
western United States and Mexico is Carnegiea gigantea. Many 
of the species of Opuntia are known as " prickly pears." Coch- 
ineal is a scarlet dye prepared from cochineal insects that feed 
upon the cochineal cactus, Nopalea cochinellifera, a species widely 
grown in semitropical countries. 



CHAPTER XIX 
THE BITTERSWEETS, MAPLES, AND PARSLEYS 

We now return to the main series in this line of Dicotyledons 
after having considered the nature of the Myrtales, Loasales, 
and CactaleSj which together are regarded as a lateral develop- 
ment from the Resales. The Celastrales lead upward from the 
Resales and thus continue the main line established by the latter 
group. The Sapindales are here treated as a lateral branch of 
the CelastraleSj but the position of the order is still very uncertain. 
Growing information seems to support the conclusion that the 
Sapindales are to be regarded as a side development from some- 
where among the Celastrales and that the line terminates with 
the diclinous oaks and birches and their kin. 

The first two orders include families in which the flowers range 
from the typically hypogynous form to the typically epigynous 
form. There are also noteworthy instances of zygomorphy 
and diclinism to be seen in these groups. The development of 
a conspicuous glandular, annular, or turgid disk connected with 
the receptacle is a prominent feature of the floral structure in 
many plants of this series. 

'jfepigyny becomes the fixed rule in Umbellales, and a high degree 
of flower aggregation is also developed in this group. This 
order continues the central series of Dicotyledons upward from 
the Celastrales. 

ORDER CELASTRALES, THE BITTERSWEET ORDER 

This group may be designated as the bittersweet or holly order. 
They are largely trees, shrubs, or woody climbers, with alter- 
nate or opposite, simple leaves and actinomorphic flowers in 
which a glandular floral disk is often a very prominent feature. 
Cases of diclinism are seen in the families of the order, but the 
species are more often monoclinic. 

THE BITTERSWEET FAMILY 

5 

This is the Celastraceae, the type family of the order (Fig. 161). 
The members of the group are mostly erect trees, shrubs, or 

254 



THE BITTERSWEETS, MAPLES, AND PARSLEYS 255 

woody climbers and these are arranged in about 45 genera and 
450 species of wide general distribution except in the colder 
portions of the earth. 

Leaves alternate or opposite, simple, membranous or leathery ; 
flowers small, greenish or white, commonly perfect, but some- 
times diclinous, actinomorphic, in axillary or terminal racemes or 
cyrnes, or solitary; calyx of 4 to 5 sepals, persistent; petals 4 to 5, 
usually free, inserted upon or below a conspicuous glandular disk 
of various form; stamens 4 to 5, free, alternate with the petals, 
inserted on or below the edge of the disk; pistil two- to five-celled, 
free or more or less imbedded in the disk, i.e. more or less 




Flu. 161. The bittersweet family, Ccla^traccae. A, flowering twig of wahoo, 
Euonymus vcrrucosus; B and <?, single flowers of Euonymus verrucosus (after 
Baillon) and E. europceus (after Kerner); D, vertical section of a flower of 
Euonymua verrucotsus (after Baillori); E, floral formula for the family, F, floral 
diagram of Euonymus (after Le ^[. and Dec.). 

inferior; style short, stigma entire, capitate, or three- to five-lobed, 
ovules 2 in each cell; fruit a capsule, berry, samara, or drupe; 
seeds with fleshy endosperm. 

A number of interesting and popular ornamental species are 
included in this family. These include the bittersweet or 
waxwort, Celastrus scandens, a climbing vine with beautiful 
orange capsules that expose crimson seeds as the fruits open in 
the autumn. Other species of Celastrus are abundant in the 
mountains of India and China. The spindletree, wahoo, or 
burning bush are species of Euonymus, such as E. atropurpureus 
or E. japonicuSj low trees or shrubs with fruits resembling those 
of the bittersweet, and sometimes with variegated leaves. 

THE GRAPE FAMILY 

This family, the Vitaeeae, includes 11 or 12 genera and 500 
species of wide distribution, but mainly developed in tropical and 
subtropical climates (Fig. 162). Certain wild species of Vitis, 
"grapes," and numerous cultivated varieties are grown in abun- 



256 FLOWERS AND FLOWERING PLANTS 

dance in temperate regions. They are largely tendril-climbing 
vines or small trees. 

Leaves alternate or opposite, simple, deeply lobed or com- 
pound; flowers small, greenish, perfect or diclinic, in spikes, 
racemes, panicles, or cymes, the peduncle often tendril-like or 
coiled; sepals 4 to 5; petals 4 to 5, free or united, inserted at base 
of the disk, falling early; stamens 4 to 5, free, opposite the petals, 
inserted at the base of the disk or in marginal lobes of the disk; 
pistil superior two-celled (2 to 6), ovules 1 to 2 in each cell, 
style 1, stigma capitate or discoid; fruit a juicy berry, with one to 
more seeds; endosperm abundant, often ruminate. 




FIG. 162. The grape family, Vitaccae. A, leaf, tendrils, and inflorescence 
of grape, Vitis labrusca; B, section of single flower of same; C, flower after 
perianth has fallen; D, seeds (after Mathews); E, floral diagram of Vitix (aftrr 
Le M. and Dec.); F, section of young fruit (Mathewa); G, floral formula for tho 
family. 

The most useful plants in this group are the grapes, i.e. species 
and varieties of Vitis, but the most abundant native plants in the 
group are the so-called "ivies" or species of Cissus, of which there 
are said to be more than 300 in tropical and subtropical lands. 
The "vine" or "grape vine" is Vitis vinifera or V. lahrusca, which 
includes many varieties such as muscatels, raisins, Concords, 
sultanas, currants, wine grapes, etc. Important ornamental high- 
climbing vines of this family are Boston ivy, and Virginia creeper, 
species of Parthenocissus, used widely for covering trellises and 
walls. 

THE BUCKTHORN FAMILY 

The Hhamnaceae, or Buckthorn family, include trees, shrubs, 
and some woody vines of very wide distribution in tropical 
and temperate climates, but absent from cold regions (Fig. 163). 



THE BITTERSWEETS, MAPLES, AND PARSLEYS 257 

About 45 genera and 500 species have been described in the 
family. 

Leaves alternate or opposite, simple; flowers small, mostly 
cymose, actinomorphic, perfect or rarely polygamo-dicecious; 
sepals 4 to 5 on a more or less tubular axis lined with the disk; 
petals 4 to 5 or 0, free; stamens 4 to 5, free, opposite the petals and 
inserted with them on the axis at or below the margin or rim of the 
fleshy disk; ovary superior or inferior, i.e. the degree of hypogyny, 
perigyny or epigyny developed varies greatly in different species, 
carpels 2 to 4, ovules 1 in each cell, stigma two- to four-lobed ; 
fruit a drupe or capsule; seeds with copious endosperm. 




FIG. 163. The buckthorn family, Rhamnac^ac. A, leaves and fruits of 
buckthorn, Rhamnus; B, vertical section of a flower of Rhamnus; C and /), 
floral diagrams of Rhamnus (all after Baillori); E, floral formula for the family. 

The important drug plant, buckthorn or cascara, Rhamnus 
purshiana, of northwestern United States, that produces cascara 
sagrada, belongs here, as do a number of other medicinal plants. 
The Indian jujube or Chinese date is Zizyphus jujuba. Many 
species of Ceanothus are represented in the bushy vegetation or 
chaparral of southwestern United States. A few species of this 
genus are grown as ornamentals. 

THE HOLLY FAMILY 

The Aquifoliaceae are a family of mostly evergreen trees and 
shrubs grouped in 3 genera and about 300 species (Fig. 164). 
They are widely distributed from their Central and South 
American center, but are comparatively rare in Africa and 
Australia. One species is common from southern Norway to 
central Turkey and westward to England. Certain other species 
are found in southeastern United States. 



258 



FLOWERS AND FLOWERING PLANTS 



Leaves alternate, simple, usually evergreen, often with spiny 
teeth on the margin; flowers actinomorphic, perfect or rarely uni- 
sexual, small, axillary or in terminal fascicles; calyx of 4 to 5, often 
4 (3 to 6) free or united sepals ; petals 4 to 5, often 4, free or connate 
at the base; stamens as many as the petals and alternate with 
them; disk absent; ovary superior, four-celled (3 to 6), each cell 
with 1 to 2 ovules; style terminal or stigma sessile; fruit drupa- 
ceous, with 2 to 4 stones; endosperm abundant, fleshy. 

The hollies are valuable as ornamental plants on account of 
their glossy evergreen leaves and bright red fruits. The English 
holly is Ilex aquifolium, and the common American holly is 7. 




FIG. 164. The holly family, Aquifoliaceae. A, leaves and flowers of holly, 
Ilex (after Le M. and Dec.); B, floral formula for the family; C, habit and details 
of the flowers of English holly, Ilex aquifolium (after Bentham). 

opaca, both of which are popular at Christmas time. Forms of 
holly with variegated leaves are also known. The South 
American Ilex paraguayensis is the source of mat6 or Paraguay 
tea. 

THE OLEASTER FAMILY 

The Elaeagnaceae are a small family including 3 genera and 30 
to 40 species of erect shrubs or low trees found mostly in the north 
temperate and subtropical portions of both the Eastern and 
Western hemispheres (Fig. 165). They are xcrophytic inhabit- 
ants of seacoasts, dry, sandy barrens, and steppes. 

Leaves and young twigs often thickly covered with golden- 
brown or silvery, peltate or stellate scales; leaves alternate or 
rarely opposite, entire; flowers perfect or unisexual, often 
dioecious, solitary or in axillary clusters on 1-year-old twigs; 
receptacle more or less tubular in the perfect and female flowers 
in which the ovary is imbedded, hence more or less epigynous; 
in the male flowers the receptacle is cup-shaped or flattish with 



THE BITTERSWEETS, MAPLES, AND PARSLEYS 259 




FIG. 165. The Russian olive family, 
Elceagnaccae. A, a flowering branch of 
Russian olive, Elceaqnus (after Baillori); B 
and C, vertical sections of flowers (after Le 
M. and Dec.); D, floral diagram of Elceagnus 
(after Le M. and Dec.); E, floral formula for 
the family. 



the stamens inserted on the throat or on the rim; sepals 2 to 4; 
petals 0; stamens as many as the sepals and alternate with them 
or twice as many, filaments free; ovary, one-celled, one-ovuled, 
more or less closely invested by the axis, style terminal, slender; 
fruit an achene or nut 
inclosed by the fleshy or 
mealy receptacle, hence 
more or less drupaceous 
or baccate ; endosperm 

scantyor - ^"^SWJ^s CO 

A few species and vari- ^ ^WV V\ W V, 
eties of Elaeagnus are 
grown for ornament. The 
fruits of E. angustifolia are 
known as Trebizond dates. 
The sea buckthorn, Hip- 
pophae rhamnoides, has 
been planted along sea- 
coasts to prevent the blow- 
ing of the sand. The buffalo berry, Shepherdia argentea, of the 
American prairie region is planted for hedges and other orna- 
mental purposes. 

THE MISTLETOE FAMILY 

The Loranthaceae, or mistletoe group, are a family of mostly 
parasitic evergreen shrubs growing upon trees, or rarely they are 
terrestrial trees and shrubs. There are 21 genera and about 500 
species of mistletoes, widely dispersed, mainly in the tropics of 
the Old and New Worlds. Such trees as chestnuts, oaks, poplars 
(Populus), and pines serve as hosts for these parasites. The 
" wooden flowers, " sometimes gathered by travelers in the 
tropics, are formed by the attachment of certain of these plants 
to the woody host. 

Leaves opposite or whorled, simple, entire, often leathery, often 
reduced to mere scales; flowers actinomorphic or slightly irreg- 
ular, perfect or diclinous, often brightly colored; axis cup-like 
or disk-like; sepals 2 to 3, free or united, or poorly developed; 
petals 2 to 3, free or united into a tube; stamens 2 to 3, inserted 
on the petals; disk present or 0; ovary inferior, one-celled, style 
simple, terminal or 0; fruit baccate or drupaceous; seed solitary; 
endosperm abundant. 



260 FLOWERS AND FLOWERING PLANTS 

The pine mistletoe of western United States, Razoumowskia, 
often does considerable damage to the trees. The popular 
Christmas mistletoe of Europe is Viscum album, of America, 
Phoradendron flavescens. The sandalwood family, Santalaceae, 
is closely related to this family. 

ORDER SAPINDALES, THE MAPLE ORDER 

This order is an important continuation of the Celastrales, with 
which it shows many unmistakable affinities. The members of 
the group are mostly trees or shrubs, and the flowers are actino- 
morphic or rarely zygomorphic, perfect or diclinous, hypogynous, 
perigynous or epigynous, often with a more or less glandular 
disk with which the stamens and perianth are closely related; 
seeds mostly without endosperm. Epigyny becomes dominant 
in the higher families of the order. 

THE SOAPBERRY FAMILY 

The Sapindaceae include about 125 genera and 1,000 species of 
trees and shrubs, with many climbers, rarely herbs of wide dis- 
tribution in tropical and subtropical countries. Some of the 
lianas in the group show a very unusual type of stem structure on 
account of a peculiar method of secondary growth involving 
the formation of cortical vascular bundles in addition to the 
regular central stele. 

Leaves alternate, rarely opposite, simple or commonly . pin- 
nately, or palmately compound; flowers often much reduced, 
perfect or polygamo-dioacious, zygomorphic or actinomorphic; 
sepals 4 to 5; petals 4 to 5 or 0; disk ring-like and well developed 
between stamens and petals, sometimes unequal; stamens 5 to 10, 
often 8, inserted within the disk, filaments free or united at the 
base; ovary superior, one- to four-celled, often three-celled, 
ovules one to two to many in each cell, style simple or divided; 
fruit often large, dry, capsular or nut-like, or fleshy and drupa- 
ceous or baccate, frequently winged; seeds without endosperm. 

The family as here treated includes the buckeyes and horse- 
chestnuts (the genus Aesculus) which are sometimes set aside as a 
special family, the Hippocastanaceae. These are trees or shrubs 
with opposite, palmately three- to nine-foliate leaves and irregular 
flowers in terminal panicles. The common horse-chestnut is 
Aesculus hippocastanum, a popular ornamental tree, native to 
southeastern Europe, but with many varieties that are culti- 
vated very widely. The American buckeye is Aesculus glabra. 



THE KITTERSWEETS, MAPLES, AND PARSLEYS 261 

Other cultivated plants of the family are: soapberry, Sapindus 
saponaria, the Chinese litchi or leechee, Litchi chinensis, and the 
balloon vine, Cardiospermum halicacabum. Certain other species 
furnish valuable timber. 

THE MAPLE FAMILY 

The Aceraceae include the genus Acer, or the maples (Fig. 
166), of which there are more than 100 species known of very wide 




FIG. 166. The maple family, Aceraceae. A, leaf of sugar mapJfe, Acer 
saccharum; B, cluster of staminate flowers of same; C, single such flower; Z>, same 
flower sectioned ; E, cluster of pistillate flowers of same ; F, single flower of same ; 
G, same flower sectioned; //, fruit of same species; /, leaf of silver maple, Acer 
saccharinum; J, cluster of staminate flowers of same; K, single flower from the 
cluster; L, cluster of pistillate flowers of same species; M, single pistillate flower; 
N, fruit of the same spe*cies; O, floral formula for the family; P, floral diagram 
for the family (P after Le M. and Dec., all the rest after Mathews). 

distribution, and the genus Dipteronia with a single species in 
central China. The maples are mostly mountain or upland 



262 FLOWERS AND FLOWERING PLANTS 

trees and shrubs, with saccharine juice, of the northern hemi- 
sphere, the greatest number of species being in the eastern 
Himalaya Mountains to central China. 

Leaves opposite, simple or palmately lobed or pinnately com- 
pound; flowers in axillary or terminal cymes or racemes, actino- 
morphic, polygamous or dioecious; sepals 4 to 5 (4-10); petals 
4 to 5, rarely 0; disk fleshy, annular or lobed, or reduced to mere 
points; stamens 4 to 10, often 8, inserted on the disk or inside 
the disk, hypogynous or perigynous, filaments elongated; ovary 
superior, two-lobed and compressed, two-celled, ovules 1 to 2 
in each cell, styles 2, inserted between the lobes of the ovary; 
fruit a dry samara, two-winged, often splitting into two parts; 
seeds without endosperm. 

Many of the maples are popular ornamentals, such as the 
American hard maple or sugar maple, Acer saccharum, Norway 
maple, A. platanoides, sycamore maple, A. pseudoplatanus, 
and silver maple, A. saccharinum. jMaple syrup and maple 
sugar are made mostly from the sap of A. saccharum, or hard 
maple. This species and others also furnish hard, durable wood 
of great value. The boxelder is A. negundo. 

THE CASHEW FAMILY 

This group, the Anacardiaceae, also known as the sumac 
family, includes about 65 genera and 500 species of trees and 
shrubs with resinous bark. They are chiefly tropical in their 
distribution but with several species extending into southern 
Europe and temperate Asia and America. 

Leaves alternate, rarely opposite, simple or compound; flowers 
small, perfect or with a tendency toward diclinisrn, usually 
actinomorphic; axis tubular, with 3 to 7 points (sepals); petals 
3 to 7, rarely 0, free or rarely connate; stamens as many or twice 
as many as the petals, inserted at the base of the annular disk, 
filameuts fr^e; ovary superior, surrounded by the fleshy cup, one- 
celled, or two- to five-celled, ovule 1 in each cell; styles 1 to 3, 
often widely separated; fruit usually a drupe; endosperm thin 
orO. 

Numerous sumacs, species of Rhus, are grown for landscape 
decoration, as is the mastic tree or California pepper tree, Schinus 
molle, a native of the American tropics. The so-called poison ivy, 
poison oak and poison sumac are also species of Rhus. The 
cashew, Anacardium occidental, of tropical America, produces a 



THE BITTERSWEETS, MAPLES, AND PARSLEYS 263 

delicious, popular, curved nut, on a greatly enlarged receptacle. 
The pistachio nut comes from Pistacia vera, a small native tree of 
the Mediterranean Basin and the Orient. 



THE WALNUT FAMILY 

This important family, Juglandaceae, includes 5 or 6 genera and 
about 35 species of deciduous trees often with resinous, aromatic, 
glandular leaves, native to the north temperate hemisphere, with 
extensions into the mountains of the northern tropics, as in the 
Andes to Bolivia (Fig. 167). Many of the species are rich in 
tannin. 




Fia. 167. The walnut family, Juglandaceae. A, leaf of butternut, Juglant 
cinerea; B, nut of same, (7, staminate catkin of same; D, single leaflet and nut 
of black walnut, Juglans nigra; E, single staminate flower of butternut; F, - 
staminato catkin of black walnut; G, single staminate flower of black walnut; 
//, cluster of pistillate flowers of butternut; /, single pistillate flower of black 
walnut; /, floral formula for the family (att after Mathews). 

Leaves alternate, pinnately compound; flowers monoecious, the 
male in pendulous, spike-like, many-flowered clusters or catkins, 
the female spikes few-flowered and erect; axis of male flowers 
three- to six-lobed, adnate to the bract; stamens many (3 to 40) 
inserted on the axis in two or more series, filaments short; female 
flowers sessile, axis cup-like, calyx three- to six-toothed or three- 
to six-lobed or 0; ovary inferior, two- to four-celled, but one- 
ovuled and finally one-celled, style short, with two plumose 
branches, ovule 1 ; fruit a drupe or nut, with dehiscent or inde- 
hiscent, fibrous husk, and stony endocarp, dividing in fruit into 



264 FLOWERS AND FLOWERING PLANTS 

2 to 4 (usually 2) compartments; seed solitary, without endo- 
'sperm; cotyledons very oily, often much lobed and contorted. 

The most valuable members of this family are the walnuts, i.e. 
species of Juglans, and the hickories, i.e. species of Hicoria. The 
American black walnut is Juglans nigra, the butternut or white 
walnut is /. cinerea, and the Persian walnut or the so-called 
English walnut is J. regia. The fine dark-colored wood of the 
black walnut and the lighter, mottled wood of Caucasus walnut 
(J. regia), known as "Circassian walnut," are among the most 
valuable economic woods in the world. 

The hickories are also important timber-producing trees, their 
light-colored, heavy, and tough wood being very useful for special 
purposes. Hickory nuts of value are produced by Hicoria ovata, 
//. laciniosa, and especially by //. pecan, the pecan of commerce of 
which there are now many varieties including the famous "paper- 
shell" forms cultivated in the South. Large quantities of these 
nuts as well as of English walnuts are now produced by planted 
orchards iri the South and on the Pacific Coast. 

THE OAK FAMILY 

The oaks, chestnuts, and the beeches are conspicuous members 
of the family Fagaceae (Fig. 168). They are trees or shrubs of 
temperate and tropical regions mostly of the northern hemi- 
sphere. Five or more genera and 600 species have been described, 
the oaks comprising about half the number of species include'd in 
the family. 

Leaves alternate, evergreen or deciduous, simple, entire, lobed, 
or cleft; flowers unisexual, plants monoecious; the male flowers in 
erect capitate clusters or in catkins; sepals 4 to 6, rarely 7; 
stamens few to many, filaments free; female flower solitary or in 
few-flowered clusters, surrounded by or inclosed by an involucre, 
axis cup- or urn-shaped; sepals 4 to 6; ovary inferior, three- to six- 
celled, ovules 1 to 2 in each cell, but only 1 ripens; styles 3 to 6; 
fruit a one-seeded nut, free or more or less inclosed by the hardened 
cupular, bur-like, spiny, or tuberculate involucre; seed solitary; 
endosperm 0. 

The oaks are among the world's most noble and valuable trees. 
Between 200 and 300 species of oaks, Quercus, have been 
described, but many of these are unimportant shrubs of waste 
places. Among the famous oaks are the English oak, Quercus 
robur, American live oak, Q. virginiana, white oak, Q. alba, red 



THE BITTERSWEETS, MAPLES, AND PARSLEYS 265 

oak, Q. borealis, cork oak, Q. suber, of southern Europe and 
northern Africa, and the pin oak, Q. palustris. 

The two famous beeches of the world are Fagus sylvatica of 
Europe, and F. grandifolia of North America. 

The American chestnut is Castanea dentata, and the European 
or Eurasian chestnut is C. saliva. 




FIG 168. The oak funnly, Fafjaccac. A, leaf of scarlet oak, Quercus coccinta; 
B, leaf of white oak, Quercu* alba; C, staminate catkin of white oak; />, single 
flower of same; E, cluster of pistillate flowers of white oak; F, single flower of 
same; (7, mature acorn of same species, //, acorn of bur oak, Q. macrocarpa; 
I, single pistillate flower of red oak, Q, boreali; J, acorn of red oak; K, acorn of 
southern live oak, Q. virc/imana; L, acorn, of willow oak, Q. phdlos; M t leaf of 
live oak (all after Mathcws). 

THE BIRCH FAMILY 

The birch family, Betulaceae, includes about 6 genera and 
100 species of deciduous trees and shrubs that occur mainly in the 
cooler portions of the northern hemisphere (Fig. 169). A few 
species occur as far south as Bengal in Asia and from Mexico 
along the Andes to Argentine. They vary from low bushy 
shrubs to giant trees. 

Leaves alternate, simple, penninerved, mostly serrate; flowers 
monoecious ; male flowers small, numerous, borne in long, pendu- 
lous terminal or lateral catkins, often developing very early as 
in the preceding autumn; sepals 2 to 4 or 0; stamens 2, 4 or 10, 
free, filaments very short; female flowers in short, cylindric, 
cone-like spikes with imbricate, three-lobed bracts, sepals four- 
parted or ; ovary inferior, compressed, two-celled, each cell with 
1 ovule; style two-parted; fruiting spikes cylindric or ovoid, the 



266 



FLOWERS AND FLOWERING PLANTS 



bracts usually falling away in birch but persistent in other genera ; 
fruit a small, indehiscent one-celled, one-seeded nut, sometimes 
included in a foliaceous involucre, or a samara, often membra- 
nous-winged and crowned by the persistent styles; endosperm 0. 
There are many useful plants in this family. Several species 
of birch are popular ornamentals, such as the white birch, Betula 

alba, in Europe and the paper 
birch B. papyrifera in Amer- 
ica. A very valuable timber 
of commerce is also furnished 
by these and other species. 

The alders, Alnus, differ 
from the birches mainly in 
their persistent and more or 
less woody cones. 

The hard-shelled nut is 
inclosed by a leaf-like in- 
volucre in the hazel, Corylus. 
The American hazel is C. 




FIG. 169. The birch family, Bctula- 
cvac. A, twig and leaves of paper birch, 
Retula papyri/era, B, fruiting catkins of 
same; C, single bract from the cones 
(after Mathews); Z), floral formula for 
the family. 



americana. The European 
and Asiatic hazel or filbert is 
C. avellana, which is com- 
monly cultivated for the nuts. 

ORDER UMBELLALES, THE PARSLEY ORDER 

This large group of woody to herbaceous plants with world- wide 
distribution is characterized by the presence of small, actinomor- 
phic usually perfect flowers arranged in umbels or heads. The 
flowers are typically 4- to 5-lobed or parted, the stamens arc 
definite in number, and the ovary is inferior. The leaves arc 
often compound and they are frequently more or less finely dis- 
sected and provided with resin canals. The fruits are often very 
resinous, and the seeds are supplied with abundant endosperm. 

THE GINSENG FAMILY 

This family, the Araliaceae, includes about 60 genera and 700 
species of trees, shrubs, and herbs of wide distribution in tem- 
perate and tropical lands, but they are much more abundant in 
the tropics, the two chief centers being in tropical America and 
the Indo-Malayan region (Fig. 170). 

Leaves alternate, rarely opposite, simple or compound, pinnate 
or digitate; flowers small, greenish or whitish, regular, perfect, 



THE BITTERSWEETS, MAPLES, AND PARSLEYS 267 

polygamous or diascious, racemose, capitate, or umbellate, 
epigynous, bearing a greatly reduced calyx of 4 to 5 points or 
teeth or none on the rim of the axis; petals usually 5, inserted 
on the rim of the axis, free or united, or cohering and falling as a 
group; stamens usually 5 or the same number as the petals, and 
alternate with them and inserted on the rim of the axis; disk at 
the top of the ovary; ovary inferior, one- to many-celled, ovules 
1 in each cell; styles free or connate, as many as cells in the ovary; 




FIG. 170. The ginseng family, Araliaceae. A, leaves and flower cluster of 
ginseng, Aralia (Mathews); B and C Y , flowers of Araha (after Baillori); D, cluster of 
fruits of Aralia; E, floral diagram of Aralia (after Lc M, and Dec.); F, floral 
formula for tho family. 

fruit a berry or drupe, or sometimes dry; seeds with copious 
endosperm. 

This family includes a number of drug plants among which are 
wild sarsaparilla, Aralia nudicauliSj American spikenard, A. 
racemosa, and the ginseng, Panax quinquefolium. 

The English ivy, Iledera helix, is an important ornamental that 
belongs here. This plant is a wall climber with beautiful ever- 
green, lobed, shiny leaves, and it is very highly prized in moist 
temperate climates. Other ornamentals of the family are the 
showy Chinese Angelica, Aralia chinensis, and the spiny Ameri- 
can Hercules club, A. spinosa. 

THE DOGWOOD FAMILY 

The cornels or dogwoods belong to the Cornaceae, a family of 
trees and shrubs, or rarely perennial herbs, including 10 genera 
and about 100 species with widely scattered distribution, but 



268 



FLOWERS AND FLOWERING PLANTS 



most abundant in the temperate portions of the northern hemi- 
sphere (Fig. 171). 

Leaves usually opposite, or rarely alternate, simple; flowers 
small, greenish or whitish, in terminal, capitate, or umbellate 
clusters, sometimes surrounded by a showy involucre, perfect or 
dioecious, epigynous, actinomorphic; calyx represented by 4 to 5 
points or lobes on the rim of the receptacle or 0; corolla of 4 to 5 
separate petals or 0, inserted on the rim of the axis along with the 
4 to 5 alternate stamens, all attached at the base of a cushion-like 
disk at the top of the ovary; ovary inferior, one- to four-celled, 




Fio. 171. The dogwood family, Cornaceae. A, branch of flowering dogwood, 
Cornus florida with two clusters of flowers, each surrounded by the involucre 
of white bracts (ufter Baillon); B, single flower of C. sanyuinca (after Le M. 
and Dec.); C, floral formula for the family; D, floral diagram for Corn us (after 
Baillori); E, another floral diagram for Cornus (after Le M. and Dec.) 

often two-celled, ovules solitary, style simple or lobed; fruit a 
one- to four-celled berry or drupe; seeds with copious endosperm. 
Several species of dogwood are planted for ornamental pur- 
poses, especially the American flowering dogwood, Cornus florida, 
famous on account of its flower clusters with four large white 
or pinkish bracts. Other species are popular because of the color 
of the twigs or leaves. The dwarf bunchberry of the northern 
woods is C. canadensis, and the red osier is C. stolonifcra. 

THE PARSLEY FAMILY 

The parsley or carrot family, the Umbelliferae, is a clearly 
denned group of herbaceous or rarely somewhat woody plants of 
very wide distribution mainly throughout north temperate and 
subtropical regions, but largely absent from the tropics except in 
the mountains. The family includes about 250 genera and 
between 2,000 and 2,500 species, many of which are more or less 
oily and aromatic (Fig. 172). 



THE B1TTERSWEETS, MAPLES, AND PARSLEYS 269 

Leaves alternate, mostly compound, sheathing at the base; 
flowers small, usually perfect, actinomorphic, epigynous, in 
simple or compound umbels, the latter often very showy; calyx 
of 5 sepals or teeth on the rim of the receptacle, or wanting; 
petals 5, on the rim of the receptacle, separate, falling early; 
stamens 5, alternate with the petals; ovary inferior, two-celled, 
ovules 1 in each cell, styles 2, thickened at the base; fruit dry, 
two-celled, dividing into 2 indehiscent mericarps, each one- 
seeded, and often winged or ridged, containing longitudinal oil 
canals to which the characteristic odor and flavor are due; seeds 
with abundant endosperm. 




FIG. 172. The parsley family, UmbeUiferae. A t Angelica (After Baillan); 
B, sectional view of a flower of Aethu^a (after Le M. and Dec.); C, floral diagram 
of carrot, Daucn* (after Baillon); D, floral diagram of fennel, Fceniculum (after 
Lc M. and Dec.}; E, floral formula for tho family. 

Many economic plants of great value are included in this family. 
Garden celery is Apium graveolens, parsley is Petroselinum 
hortense, parsnip, Pastinaca saliva, carrot, Daucus carota, anise is 
Pimpinella anisum, and caraway, Carum carvi. The myrrh of 
the ancients was probably Myrrhis odorata. Certain species are 
poisonous, as is poison hemlock, Conium maculatum. 

The members of this family can usually be recognized by the 
numerous small flowers closely grouped in conspicuous, simple or 
compound umbels. The flowers on the border of the umbels are 
sometimes larger than others, and these are sometimes sterile 
and more or less zygomorphic, a condition somewhat similar to 
that seen in many of the Compositae. 



CHAPTER XX 
THE MADDERS, BLUEBELLS, AND ASTERS 

In this group of orders the axis of the flower is normally 
expanded to form a cup- or urn-shaped sheath which completely 
envelops and is united with the syncarpous ovary, which bears 
the perianth on its margin, i.e. the flower is epigynous. The 
petals are united to form a more or less tubular corolla, inserted at 
the top of the axis. The stamens are as many as the corolla 
lobes and mostly epipetalous. Carpels few, united; ovary 
inferior. 

ORDER RUBIALES, THE MADDER ORDER 

The families of this order include trees, shrubs, and herbs with 
opposite leaves and 4- to 5-merous, actinomorphic or zygomorphic 
flowers, with inferior ovary of 2 to 8 cells, inconspicuous calyx and 
sympetalous corolla. PJpigyny, sympetaly, and epipetaly are 
noteworthy features of the group. 

THE MADDER FAMILY 

The madders are included in the large and distinctive family 
Rubiaceae (Fig. 173). They are mostly trees and shrubs, or 
rarely herbs and climbers of wide distribution in the tropics, 
but also with numerous extensions into the temperate and frigid 
zones. There are about 350 genera and 4,500 species described 
for the family. 

Leaves opposite or verticillate, simple, entire or rarely more 
or less toothed, stipules sometimes leaf-like and scarcely dis- 
tinguished from the true leaves; flowers mostly perfect, actino- 
morphic, rarely zygomorphic, solitary or in capitate clusters; 
ovary inferior, bearing on the rim of the receptacle 2 to 6 sepals, 
or sepals 0; corolla tubular, 4- to 5-lobed, on the axis inside the 
rim; stamens as many as the corolla lobes and alternate with 
them, inserted on the corolla tube ; carpels one to eight, mostly 2, 
united, inferior, ovules one to many in each cell, style 1, slender, 
often lobed; fruit a capsule, berry, or drupe; endosperm abundant 
or 0. 

370 



THE MADDERS, BLUEBELLS, AND ASTERS 



271 



The family includes many economic plants of first rank, among 
which are the following: coffee, Coffea arabica, an evergreen shrub 
or low tree of tropical Africa and Asia, and widely cultivated; the 
quinine plant, Cinchona officinalis, of the 4 n des, an d widely 
grown in India, Java, Jamaica, Australia, etc.; Ipecacuanha, 
Psychotria ipecacuanha, of tropical South America; and many 
others that are grown for ornamental purposes. The cape 
jasmine is Gardenia jasminoides. 




FIG. 173. The coffee family, Rubiaceae. A, leaves and fruits of coffee, 
Coffea arabica; B, single flower of Coffea; C, flower of cinchona, Cinchona; D, 
vertical section of flower of madder, Rubia; E, flower of Rubia; F. leaves and fruits 
of Gahitm; G, floral diagram of Rubia (all after Baillon); H, floral formula for the 
family. 

THE HONEYSUCKLE FAMILY 

The honeysuckles constitute the natural family Caprifoliaceae, 
a group of shrubs and vines with rather soft wood, many of them 
evergreen, with wide distribution mainly in the north temperate 
zone and in the mountains of the tropics (Fig. 174). The 
family includes 11 genera and about 350 species. 

Leaves opposite, simple or pinnately divided; flowers perfect, 
actinomorphic, but commonly zygomorphic; calyx of 4 to 5 teeth 
or lobes on the rim of the receptacle; corolla sympetalous; 
four- to five-lobed, tubular, or rotate, sometimes bilabiate; 
stamens as many as the lobes of the corolla and inserted on the 
tube alternate with the lobes; ovary inferior, two- to five-celled, 
with 1 or more ovules in each cell, style 1, terminal, slender or 



272 



FLOWERS AND FLOWERING PLANTS 



0, stigmas 2 to 5; fruit a berry or rarely a capsule; seeds with 
bony testa; endosperm abundant, fleshy. 

The honeysuckles are mostly familiar in the many bushy 
shrubs or low trees and vines that are popular ornamentals. 
The genus Lonicera includes 175 species of the northern hemi- 
sphere, many of which are widely cultivated outside their natural 
range. The more common climbing ones are L. semper vir ens, 
L. japonica, and L. periclymenum. Among the popular bush- 
honeysuckles are L. tatarica and L. involucrata. Other promi- 
nent members of the family are the elders, species of Sambucus, 




FIG. 174. The honeysuckle family, Caprifoliaceac. A, flowering twig of 
honeysuckle, Lonicera (after Le M. and Dec.); D and C, flowers of buckbrush, 
Symphoricarpos (after Baillori); D, leaves and flowers of twin flower, Linnaea 
(after Baillori); E, flower of buttonbush, Cephalanthus (Rubiaceae); F and G, 
floral diagrams of honeysuckle, Lonicera (after Le M. and Dec.); H, floral diagram 
of buckbrush, Symphoricarpos (after Baillori); 7, floral formula for the family 
showing both actinomorphic and zygomorphic types. 

the black haw, and the highbush cranberry and their kin, Vibur- 
num spp. the snowberry, Symphoricarpos, and twin flower, 
Linnaea borealis, named -after the great Linnaeus. 

THE VALERIAN FAMILY 

The members of the Valerianaceae are perennial or annual 
herbs (rarely shrubs) of the northern hemisphere, often with 
unpleasantly odorous underground parts. There have been 10 
genera and about 350 species included in the group. 

Leaves opposite or all basal, often divided; flowers small, 
perfect or polygamo-dicecious, in conspicuous cymose or capi- 



THE MADDERS, BLUEBELLS, AND ASTERS 273 

tate clusters, actinomorphic, but often somewhat zygomorphic, 
epigynous; calyx reduced to a ring at the top of the inferior 
ovary, becoming enlarged and its parts or lobes more or less 
plumose in fruit; corolla sympetalous, tubular, the tube often 
five-lobed or cleft, somewhat irregular, often saccate or spurred 
at the base; stamens 1 to 3 or 4, inserted on the corolla tube and 
alternate with its lobes; ovary inferior, one- to three-celled, 2 
of the cells abortive, ovule 1, style slender, simple; fruit dry 
and indehiscent, an achene, sometimes crowned by the beauti- 
fully radiate calyx (pappus) with its many plumose segments or 
by a crown of bristles or hooks; seeds with scanty or endosperm. 
Spikenard, a famous drug of the Ancients was secured from the 
young shoots of Nardostachyos jatamansi, a Himalayan plant. 
The rhizomes of certain species of Valeriana, especially V. 
officinalisj furnish a penetrating oil of value in medicine. Certain 
others, as Valerianella olitoria, are grown in the vegetable garden 
and are used as salad plants. 

THE TEASEL FAMILY 

The teasels, Dipsacaceae, are perennial or annual herbs of the 
Old World, but with almost world- wide introduction. Their 
natural home appears to be in the eastern Mediterranean region. 
The family includes 9 genera and 150 species. 

Leaves opposite or verticillate, entire, toothed or deeply cleft, 
often very rough ; flowers small, perfect, zygomorphic, epigynous, 
in dense, bracted, involucrate heads; calyx poorly developed, 
cup-like or divided into bristly segments (pappus) on the rim of 
the receptacle, each flower more or less enveloped by an 
"epicalyx" formed by the surrounding bracts; corolla tubular or 
funnel-form, four- to five-lobed, inserted near the center of the 
axis; stamens usually 4 or 2 to 3, alternate with the corolla lobes, 
at the base of the tube, filaments free or united in pairs; ovary 
inferior, one-celled, ovule 1, style filiform, stigma simple or 
bifid; fruit an achene, one-seeded, inclosed by the epicalyx and 
often crowned by the persistent, bristly or spiny calyx or pappus. 

Teasels are grown for commercial or ornamental purposes. 
The fruiting heads of Fuller's teasel, Dipsacus fullonum, are used 
in raising the nap on woolen cloth. The pincushion flower or 
mourning bride is some species of Scabiosa, sweet scabious being 
S. atropurpurea, a popular, coarse ornamental of southern Europe. 



274 



FLOWERS AND FLOWERING PLANTS 



This group is of peculiar interest, along with the Valerianaceae, 
on account of the many resemblances to the Compositae which 
they exhibit. 

ORDER CAMPANULALES, THE BLUEBELL ORDER 

These plants are herbaceous to somewhat woody, and the 
flowers are usually perfect, actinomorphic or zygornorphic, 
epigynous, sympetalous. The stamens are free or connate by 
their anthers and often forming a tube in which the pollen collects, 
later to be swept out as the brush-like style pushes up through the 
tube. Ovary one- to several-celled, commonly three-celled, 
ovules numerous. Inflorescence racemose, or more or less 
capitate. 

THE BELLFLOWER FAMILY 

This family, the Campari ulaceae, is also sometimes known as 
the bluebell family (Fig. 175). It includes about 50 genera and 




FIG. 175. The bluebell family, Campanulaceae. A, flowering stems of 
bluebell, Campanula rotundifolia (after Le M. and Dec.); B, single flower of 
Campanula (after BaiUori); (7, single flower of Lobelia (after Baillori), D, floral 
diagram of Campanula (after Le M. and Dec.}; E, floral diagram of lobelia, 
Lobelia (after Baillon); F, floral diagram of Campanula (after Baillon); G, floral 
formula for the family showing both the actinomorphic type (Campanula} 
and the zygomorphic type (Lobelia). 

1,000 to 1,500 species of annual or perennial herbs (rarely woody) 
often with milky juice. They are cosmopolitan in range and are 
very common in temperate and subtropical regions, often extend- 
ing into cold climates in the north and in high mountains. 

Leaves usually alternate, rarely opposite, simple, rarely lobed 
or divided; flowers perfect, actinomorphic or zygomorphic, often 



THE MADDERS, BLUEBELLS, AND ASTERS 



275 



large and very showy, solitary, spicate, racemose or paniculate, 
epigynous; calyx of 3 to 10, commonly 5, sepals inserted on the 
rim of the axis, usually persistent on the fruit; corolla sympetalous, 
tubular or campanulate, five-lobed or five-divided, often blue; 
stamens 5, inserted near the base of the corolla tube or on the 
axis, filaments dilated, free or united, anthers sometimes more or 
less connate, forming a pollen chamber (in Lobelia) ; ovary two 
to five-celled, often three-celled, rarely one-celled, ovules numer- 
ous, style simple, stigmas 2 to 5, often 3, with pollen-sweeping 
brushes; fruit a capsule, seeds numerous; endosperm fleshy. 

This family includes many 
beautiful wild flowers and choice 
cultivated ornamentals. The 
bluebell or harebell is Campan- 
ula rotundifolia, and Canter- 
bury bells is C. media. Another 
choice plant of the garden is the 
balloon ftower,Platycodongramh- 
florum, prized for its very large 
blue or white bell-shaped flowers. 
The lobelias are also sometimes 
included in this family. The 
cardinal flower, Lobelia cardi- 
naZt'.s, is a well-known member of 
this group. 



ORDER ASTERALES, THE ASTER 
ORDER 




FIG. 176. The composite family, 
Compositae. Flowering habit and 

hoada of typical composite , an aste r, 

Aster novi-beloU (after Mathewa). 



This group, Commonly known 
,1 r+ ., . ,1 , , 

as the Composites, is the largest 

Order of the vegetable kingdom 

(Figs. 176 to 180). Various 

authors estimate the number of genera included from 800 to 
1,000, and the number of species from 15,000 to 23,000. They 
are very widely distributed in all parts of the world and under 
very diverse habitat conditions. 

The Composites may usually be recognized by the presence of 
few to many small flowers arranged in dense involucrate heads 
(Figs. 176, 178 and 179). The individual flower (Fig. 177) 
is actinomorphic or zygomorphic, epigynous, perfect, unisexual 
or sterile; calyx reduced to a pappus (Fig. 177) on the rim of the 



276 FLOWERS AND FLOWERING PLANTS 

receptacle or 0; corolla sympetalous, tubular, inserted on the 
receptacle inside the calyx ring; stamens epipetalous, usually 
with connate anthers; carpels 2, united, ovary inferior, one-celled; 
fruit an achene. 

The Composites are regarded as the highest flowering plants on 
account of their noteworthy and obvious success in nature as 
indicated by their great preponderance and cosmopolitan range. 
This success is probably largely explained on the basis of the 
perfection reached in the development of the densely aggregated 
inflorescence containing numerous small flowers so closely grouped 
as to serve almost as a single flower in the matter of pollination. 
Dozens of flowers may thus be pollinated by a single visit of the 
proper insect, whereas a similar visit to the flowers of many other 
plants would result in the pollination of a single flower. Pollen 
mechanisms, pollen protection, and nectar placements, etc. 
are so perfectly worked out that cross-pollination by highly 
specialized insects becomes an unusually prominent feature of the 
group. 

This group has been included as a family of the order Cam- 
panulales, but it is generally so readily distinguished from 
those plants that we prefer to give it somewhat more distinctive 
treatment. The common classification divides the family thus 
set apart into 12 to 14 subfamilies or tribes. In his last treat- 
ment Bessey divided this order, which he called Asterales, 
into fourteen families, these being the approximate equivalents 
of the usual tribes or subfamilies. We shall include a somewhat 
more detailed description under the following family and will 
then point out some of the more striking and distinctive features 
of a few of the tribes. 

THE COMPOSITE FAMILY 

This vast cosmopolitan family, the Compositae, includes about 
1,000 genera and 15,000 to 23,000 species mostly of annual and 
perennial herbs, with a few shrubs or low trees (Figs. 176 to 180). 
It is reported that the single genus Senecio includes more than 
2,000 species. Nearly every conceivable habit and form of 
body known for plants is seen among the species of this family 
in some portion of its world- wide range. They abound under 
desert conditions and a few of them are true aquatics, and every 
habitat gradation between these extremes is likely to reveal 



THE MADDERS, BLUEBELLS, AND ASTERS 



277 



the presence of species of Composites. They are found in abun- 
dance in tropical lands and in cold Arctic-alpine areas. 

Leaves generally alternate, but often opposite or whorled, 
extremely varied, frequently crowded in basal rosettes; flowers 
(florets) small, in few- to many-flowered heads, closely grouped 
on a common disk-like, dome-shaped, conical or cylindrical axis 
which is surrounded by an involucre composed of few to many, 
more or less leafy or scaly, bracts (Figs. 176 to 180), thus produc- 
ing a flower cluster resembling a single flower in which the 
involucre is the calyx and the massed flowers the corolla, a struc- 
ture which, popularly, commonly passes as a single flower; each 
flower (Fig. 177) on this disk may be accompanied by a scale-like 




FIG. 177. A, vertical section through the inflorescence (head) in the Com- 
pomtae, as in Helemum showing receptacle, involucre, ray flowers, and disk 
flowers (after Baillon}; B, single, perfect flower of Eupatonum (after Le M. and 
Dec.); C, same of groundsel, Scnecw (after Le M. and Dec.); D, sectional view of 
a disk flower of sunflower, Helianthus (after Baillon); E, disk flower of Gaillardia 
(after BaiUon); F, ray flower of sunflower, Hehanthus (after Baillon}; G, ray 
flower of HfUcnium (after Baillori); H, ray flower of Gaillardia (after Baillon); 
/, floral formula for the family, including actionmorphic and zygomorphic 
forms. 

or bristly structure which probably is to be regarded as the floral 
bract, in which case the receptacle is said to be "scaly, " "chaffy," 
"bristly/' etc., or such structure may be lacking, and then the 
receptacle is "naked." The head thus constituted is represented 
in the family by three different types: in one form there is a 
fringe of several to many radiating, zygomorphic (ligulate) 
flowers (Fig. 177, A, F, and G) on the margin of the common 
receptacle just inside the involucrai bracts, and the rest of the 
flowers covering the axis (disk flowers) are actinomorphic 



278 



FLOWERS AND FLOWERING PLANTS 



(Fig. 177, B, C, D, and E), the outer flowers being called "ray 
flowers" and the inner flowers the "disk flowers"; in another 
type of head, all of the flowers are zygomorphic (ligulate) and 
there is no true distinction, therefore, between ray flowers and 
disk flowers; in the third type of head all of the flowers are actino- 
morphic; the ray flowers are either female or sterile; the disk 
flowers are usually perfect, sometimes unisexual, rarely dioecious; 
calyx reduced to a low ring, or crown, or a fringe of scaly, bris- 
tly, or hairy appendages on the rim of the floral axis which often 
persist on the ripe fruit; corolla sympetalous, five-lobed or five- 
divided, actinomorphic (in disk flowers) or zygomorphic, bilabiate 
or ligulate (in ray flowers); stamens 5, inserted on the corolla 
tube (Fig. 177, D) filaments separate, anthers usually united 




FIG. 178. The dandelion, Taraxacum taraxacum. A, loaves, old, closed 
head, and open head; B, single flower, C, receptacle with a few fruits; D, single 
fruit with pappus; E, young head (after Le M. and Dec.). 

to form a tube; ovary inferior (Fig. 177), of 2 carpels, but one- 
celled, style slender, mostly two-lobed or two-parted in the 
perfect flowers, style branches provided with various types 
of pollen-collecting hairs or brushes; fruit a one-seeded achene of 
great variety of form, bearing the persistent calyx as a crown or 
tuft of pappus scales, bristles, or hairs of extreme diversity of 
form and development (Figs. 177, 178, 179) which often aid 
greatly in the dissemination of the species; endosperm 0. 

The family includes many useful species and varieties that are 
of value as ornamentals, and others contribute foods. To men- 
tion the Chrysanthemum, Dahlia, Zinnia, Aster, Calendula, Cen- 
taurea, is to indicate their value as cultivated ornamentals. There 
are also many troublesome and pernicious weeds* in this family; 
among which are dandelion, Taraxacum taraxacum (Fig. 178), 



THE MADDERS, BLUEBELLS, AND* ASTERS 279 

Canada thistle, Cirsium arvense; burdock, Arctium lappa; 
sunflowers, Helianthus spp.; and the hay-fever weeds, such as 
Ambrosia spp. (Fig. 180). 

The Compositae are usually divided into a number (12 to 14) of 
subfamilies or tribes. The following artificial key will serve to 
indicate some of the more common differences and similarities 
that are useful in the classification of the members of the group 
and in the differentiation of the various tribes. An English name 
is suggested for each tribe. 

KEY TO THE TRIBES OF COMPOSITES 

A. Pappus generally of two or more scales or rigid awns, not hairy or 
capillary; coarse herbs or shrubs, rarely trees 

1. Receptacle with chaffy scales or bracts 

a. Heads with many complete flowers, including marginal ray 

flowers Heliantheae, the sunflowers 

6. Heads with few reduced flowers, sometimes diclinous 

Atnbromeae, the ragweeds 

2. Receptacle naked, i.e. without scales or chaff, or rarely with them 

a. Anthers without appendages 

(1) Involucral bracts usually in two series, slightly imbricated. 

Helemeae, the heleniums 

(2) Involucral bracts usually in several series, well imbricated. . 

Arctotideae, the gazanias 

b. Anthers with basal appendages or mucronate at' the tip .... 

Calenduleae, the marigolds 

B. Pappus mostly capillary; plants usually coarse 

1 Involucral bracts in more than one series, more or less imbricated 

a. Involucral bracts in several series, imbricated; receptacle usually 
bristly; flowers all tubular Cynareae^ the thistles 

b. Involucral bracts slightly imbricated; receptacle usually naked 

(1) Flowers all bilabiate; juice watery. .Mutisieae, the mutisias 

(2) Flowers all ligulate; juice milky. . . . Cichorieae, the chicories 
2. Involucral bracts usually in a single series, valvate, or with an 

additional short, outer series; with or without rays 

Senecioneae, the ragworts 

C. Pappus from short bracteose to capillary or none; receptacle usually 
naked; plants typically low to medium sized 

1. Heads usually with ray flowers; pappus capillary. . Astereae, the asters 

2. Heads usually without ray flowers 

a. Involucral bracts green, imbricated in two to many series 

(1) Pappus plumose, or heads spicate. . Eupatorieae, the boneaets 

(2) Pappus never plumose nor heads spicate 

Vernonieae, the ironweeds 

b. Involucral bracts scarious, little, or not at all imbricated; pappus 
capillary Inuleae, the everlastings 

D. Pappus a short crown, or none; involucral bracts dry, imbricated; heads 
often with white ray flowers. . Anthemideae, the chrysanthemums 



280 



FLOWERS AND FLOWERING PLANTS 



The Heliantheae or sunflower tribe, include the common sun- 
flowers which belong to the genus Helianthus, as well as many 
other genera and species some of which are prized ornamentals 
and others are worthless weeds. Coneflowers, Hudbeckia; zinnias, 
Zinnia; cosmos, Cosmos; dahlias, Dahlia; tickseeds, Coreopsis, 
are additional prominent members of this tribe. The group 
is largely American in its natural distribution. 

The Ambrosieae or ragweed tribe, are sometimes regarded as a 
subdivision of the Heliantheae and as a separate family (Fig. 180). 




FIG. 179. The chicory, Cichonum intybu*,. A, upper part of plant with 
open heads below, and young, unopened heads above; B, single flower; C, ripe 
achene (after Mathews}. 

The tribe as here treated includes the ragweeds or the species of 
Ambrosia, especially A. artemisiaefolia, A. trifida, etc., well-known 
hay-fever plants. The troublesome cockleburs, species of Xan- 
thium, also occur here, as do white weeds, Gaertneria. 

The Helenieae or the heleniums often look like sunflowers. 
They are mostly plants of Mexico and western United 
States. The gaillardias, species of Gaillardia, are often seen in 
cultivation. 

The Arctotideae, the arctotis or gazania tribe, are ^ small group, 
largely confined to Africa. 



THE MADDERS, BLUEBELLS, AND ASTERS 281 

The members of the Calenduleae, or marigold tribe, are also 
mostly African in their natural distribution, but the common 
African marigold, Calendula officinalis (Fig. 18) is widely cultiva- 
ted as a very popular potplant. The large, bright yellow or 
orange heads of this plant are often used for table decoration 
during the winter months in the northern hemisphere. 

Most plants called ' 'thistles" are included in the Cynareae. 
The main center of distribution of these plants is the Mediter- 
ranean region. An old-fashioned garden flower within this tribe 
is the bluebottle or cornflower, Centaur ea cyanus. About 500 
species of Centaurea have been recognized. The globe artichoke 
is the unopened heads of Cynara scolymus, with its thick, imbri- 
cated involucral bracts. Many worthless weeds such as burdock, 
Arclium lappa, and Canada thistle, Cirsium arvensc, also belong 
here. 

The Mutisieae include a small number of African and Asiatic 
species of herbs and South American woody climbers that are 
interesting because of their bilabiate flowers. 

The Cichorieae, often called the lettuce or chicory tribe, are 
sometimes regarded as a separate family. The heads composed 
solely of strap-shaped or ligulate flowers (Fig. 179) and the 
frequently present milky juice make these plants readily 
recognized. They are very widely distributed, but they are 
especially numerous in the Old World. Chicory is Cichoriam 
intybus, and endive is C. endivia, the former cultivated for its 
root from which a coffee substitute or adulterant is prepared, 
the latter grown as a salad plant. Vegetable oyster, or salsify 
is Tragopogon porrifolius, and the cultivated varieties of lettuce, 
of which there are more than 100, have been derived from some 
species of Lactuca. The dandelions (Fig. 178) also belong in this 
tribe. These are species of Taraxacum, of which there are five 
or six common ones and nearly 100 have been described. 

The Senecioneae, the ragworts or groundsels, are recognized by 
the fact that the involucre is usually made up of a single row of 
valvate bracts which are often more or less united below into a 
cup. They are widely distributed. There are more than 2,300 
species of Senecio known, among them being S. cruentus, a native 
of the Canary Islands, from which the Cinerarias of the florists 
have been derived. There are many types of this plant in culti- 
vation, and they are generally marked by the bright, purplish- 
red ray flowers, as well as various shades of pink and blue. 



282 



FLOWERS AND FLOWERING PLANTS 



The Astereae or aster tribe, are also a large tribe of wide distri- 
bution but they are more numerous in the New World. This 
group includes the English daisy Bellis perennis, as well as the 
large genus Aster, of which there are more than 200 species of wide 
distribution especially in North America. There are many 
cultivated species and varieties of Aster including New England 
aster A. novae-angliaCj New York aster, A. novi-belgii (Fig. 176) 
etc. The large heads of flowers develop a great many colors 
and shades to which their popularity is due. The goldenrods, 
species of Solidago, also belong to this tribe. 




FIG. 180. The ragweed, Ambrosia sp. A, leaves and flowering shoots; B, 
single pistillate flower; C, single staminatc flower (after Baillon). 

The members of the Eupatorieae or bonesct tribe, are raylcss 
composites of general distribution in the Western Hemisphere. 
Certain species are cultivated under glass and out of doors as 
border plants, especially species of Ageratum, such as A. hous- 
tonianum. The Joe Pye weed is Eupatorium purpureum, and the 
white snakeroot is E. urticaefolium, both being ornamental species 
of the United States. 

The ironweeds, Tribe Vernonieae, are common to America, 
Africa, Asia, and Australia. Many species of Vernonia are known 
from various centers. Stokes' aster, Stokesia laevis, is sometimes 
seen in cultivation, but the most of the species of the tribe are 
worthless weeds. 

The Inuleae or the everlastings, are often woolty, or dry and 
more or less scaly plants, or plants with papery flowers and 



THE MADDERS, BLUEBELLS AND ASTERS 283 

bracts. The edelweiss of Switzerland is Leontopodium alpinum, 
a plant covered with white wool, and with large heads in which 
the bracts are petal-like and pure white. Certain species of 
Gnaphalium are of the same general nature. Strawflowers are 
usually species of Helichrysum, especially //. bracteatum, in which 
the dry, involucral bracts are developed in many series and are 
of many shades of red, yellow, orange, or white. This plant is a 
native of Australia. The Rose of Jericho, Odontospermum pyg- 
maeum, also belongs here, as does the " vegetable sheep," Raoulia, 
which forms cushion-like growths in the mountains of New 
Zealand. 

The Anthemideaej or chrysanthemum, tribe include many 
species with highly scented or aromatic leaves and flowers. 
The numerous species and varieties of Chrysanthemum are 
perhaps the best known types of the tribe. Many of the species 
are known under quite different names; for instance, the common 
pyrethrum is Chrysanthemum coccineum, the marguerite is C. 
frutescens, and Sweet Mary is C. balsamita. The sources of many 
of the cultivated varieties of Chrysanthemum are C. indicum and 
C. sinense, native to China and Japan. The common tansy is 
Tanacetum vulgare, and yarrow or milfoil is Achillea ptarmica, or 
A. millcfolium. The sagebrush is one of several species of 
Artemisia, certain species of which, such as A. tridentata and A. 
frigida, have very wide distribution in North America. 



CHAPTER XXI 

SELECTED ORDERS AND FAMILIES 
OF MONOCOTYLEDONS 

The Monocotyledons are now regarded as having been derived 
from ancestors resembling the primitive Dicotyledons at a 
comparatively early period during the evolution of the flowering 
plants. It seems probable that their point of divergence from 
the more primitive dicotyledonous stock was from ancestors 
that were more or less similar to the Kanalian types of today, 
possibly from the same general group of primitive flowering 
plants which gave rise to the Ranalian plexus from which the 
modern Dicotyledons have also developed. 

The Monocotyledon Series. It will be recalled that our 
treatment of the Dicotyledons reflects the opinion that the group 
includes two principal series. Both of these two series have 
their origin in the Ranalian complex (Fig. 96), and the one termi- 
nates in the mints, Lamiales, and snapdragons, Scrophularialcs, 
and the other ends in the Composites, Asterales. The Mono- 
cotyledons constitute a third main line of development that 
originated from about the same ancestral forms and this series 
terminates in the orchids, Orchidales (Fig. 96). Each of these 
three main branches of the modern flowering-plant stock has 
given rise to several lateral branches, as has already been indi- 
cated for the Dicotyledons. 

Vegetative Nature of Monocotyledons. The stems of Mono- 
cotyledons are typically characterized by the presence of fibro- 
vascular bundles scattered throughout (Fig. 181) the more or 
less cylindrical mass of ground tissue so completely that there is 
usually no clear or striking distinction into pith, vascular cyl- 
inder, and cortex, as in Dicotyledons. Monocotyledons also lack 
the annual layers of growth (annual rings), and sharp demarca- 
tion of pith, wood, and bark that are so characteristic of most 
woody Dicotyledons. These features are especially contrasted 
as one examines transverse sections of the steeps of the two 
types. 

284 



ORDERS AND FAMILIES OF MONOCOTYLEDONS 285 



Growth and Length of Life. Monocotyledons are annual or 
perennial, but the stems of the perennials reach their diameter 
maximum rather early, after which the growth is mostly terminal. 
This type of growth of the stem is described as " endogenous," in 
contrast to that of Dicotyledons which is described as "exogenous. " 
The erect stems of perennial, woody Monocotyledons (palms) are 
not so freely branched as are such stems in Dicotyledons. Many 
perennial Monocotyledons die back 
to the surface of the ground each 
fall, and the new growth of erect 
stem in each succeeding year is 
produced from the crown or from 
underground stems or rhizomes, 
bulbs, conns, or tubers which are 
very commonly produced by these 
plants. The species of this group 
are largely herbaceous in nature, 
but conspicuously woody and tree- 
like forms are developed among the 
palms, bamboos, and others. 

The Embryo and Seed. The 
embryo of the Monocotyledon 
produces but a single primary leaf 
or cotyledon and this is often so 
greatly modified as to lose all 
resemblance to the cotyledons of 
the Dicotyledons. The cotyledon 
in many cases is an organ of 
digestion and assimilation and it 
is often permanently retained by 
the seed during germination. The 
secondary and mature leaves are 

commonly alternate, simple, parallel veined, and are often 
attached to the stem by a sheathing base, and without clear 
distinction of petiole and blade (Fig. 181). 

The Flowers of Monocotyledons. The flower parts of 
Monocotyledons are typically in groups of three (trimerous) 
or multiples of three, i.e. there are often three sepals, three 
petals, three or six stamens, and three pistils or carpels (Fig. 
181). The flowers in certain groups are variously incomplete 
or imperfect. 




Fia. 181. The general mor- 
phology and anatomy of Mono- 
cotyledons. A, leaf; B, section of 
the stem, C, floral diagram; />, 
fronfc view of the flower; E, sec- 
tion of seed (after Gager, General 
Botany, published by P. Blakis- 
ton's Son & Co.). 



286 FLOWERS AND FLOWERING PLANTS 

The orders of Monocotyledons may be arranged in two main 
groups or subclasses, the Plypogynae and the Epigynae. The 
former includes the lower orders and families in which the flowers 
are commonly hypogynous, the latter includes the higher orders 
and families in which the flowers are epigynous. 

HYPOGYNOUS MONOCOTYLEDONS 

This subclass includes the more primitive orders and families 
of Monocotyledons, as is clearly indicated by the similarities 
which they show to the Ranales. The axis of the flower is more 
or less cone-shaped, spheroidal, or flattened, and this bears the 
hypogynous perianth and stamens, and the many or few, separate 
or united, superior carpels. A certain degree of sympetaly is 
seen in some forms, and the stamens are inserted on the perianth 
in certain species. The flowers in this series are usually 
actinomorphic, but there is a slight tendency towards zygo- 
morphy also seen in some families. 

ORDER ALISMALES, THE WATER PLANTAIN ORDER 

This group is regarded as the one that stands closest of all 
Monocotyledons to the point from which they diverged from the 
Dicotyledons, in other words these are the lowest Monocotyledons. 
The floral pattern often bears a striking resemblance to that 
in the Ranales except for the number of perianth segments. 
Carpels one to many, separate, superior; perianth conspicuous, or 
lacking. Plants largely aquatic, or paludose herbs. 

THE WATER PLANTAIN FAMILY 

The Alismaceae, the water plantains (Fig. 182) or arrowheads, 
include perennial aquatic or marsh herbs with scapose stems 
and long-petioled, basal leaves and more or less showy flowers. 
The family includes about 14 genera and 60 species of very wide 
distribution in fresh-water habitats in temperate and warm 
climates. 

Leaves simple, mostly basal, sheathing, often more or less 
sagittate; petioles long, very variable in outline; flowers actino- 
morphic, perfect, monoecious or dioecious, in racemose or panicu- 
late clusters; receptacle flat, convex or more or less cone-shaped; 
sepals 3, free, commonly persistent; petals 3, separate, often white, 
deciduous; stamens, six to many, more or less spirally arranged, 



ORDERS AND FAMILIES OF MONOCOTYLEDONS 287 

free, hypogynous; carpels six to many, separate, usually with a 
single ovule in each carpel; fruit commonly a head of many 
achenes; seeds without endosperm. 

Conspicuous plants of this family are the Old World water 
plantain, Alisma plantago-aquatica and the American, Alisma 
subcor datum, often seen in shallow water and marshy places. 
The arrowheads belong to the genus Sagittaria, of which there 
are many species of wide distribution and diverse form. 




FIG. 182. The water plantain family, Ahsmaceae. A, flowering stem of 
arrowhead, Sagittaria (after Le M. and Dec.); B, floral diagram of water plantain, 
Alisma (after Le, M. and Dec.); C, floral formula for the family; D, a leaf of 
arrowhead, Sagittana. 



THE ARROWGRASS FAMILY 

This is the Scheuchzeriaceae, named after two brothers by the 
name of Scheuchzer, Swiss botanists of the latter part of the seven- 
teenth century. These are marsh herbs with rush-like leaves, 
often growing in standing saline water or fresh- water bogs. 
There are 4 genera and about 12 species in the family, of wide 
distribution in temperate and subarctic regions. 

Leaves mostly basal, rush-like, broadly sheathing at the base; 
flowers small, perfect, actinomorphic, hypogynous, in naked 
terminal spikes or in few-flowered, loose racemes; petals 3; sepals 
3, colored alike but distinct in position; stamens 3 to 6, free, 
commonly 6 in 2 whorls, filaments commonly very short; carpels 
3 to 6, separate or more or less united, separating when mature, 
ovules 1 to 2 in each carpel; fruit follicle-like, one- to two-seeded, 
dehiscent, the separate carpels more or less coriaceous and 
cylindrical; seeds without endosperm. 



FLOWERS AND FLOWERING PLANTS 



THE PONDWEED FAMILY 

The Zannichelliaceae or pond weeds, include perennial, aquatic 
herbs of saline or fresh water, many species of which are sub- 
merged (Fig. 183). The family includes 5 to 9 genera and about 
75 species of very wide distribution, in fresh-water rivers, ponds, 
lakes and in brackish water along the seacoast and in the interior. 
The main stem is usually a branching rhizome that spreads 
through the mud, rooting at the nodes. 

Leaves alternate or the uppermost sometimes opposite, sessile; 
or with petiole, often with sheathing base, the blade expanded or 
capillary or reduced to scales, often of two kinds, one submerged 
and reduced, the other broadened and 
floating; flowers small, inconspicuous, 
perfect or unisexual, in sessile or 
peduncled, terminal spikes, projecting 
above the surface of the water or in 
D axillary clusters; calyx 0, corolla 0, or 
flower inclosed by a four-lobed sheath 
formed by the excessive development of 
the connective between the pollen sacs 
of the anthers; stamens 1 to 4; carpels 
1 to 4, separate, each with 1 ovule; fruit 




CA ) Co ) S' 4 P' 4 ' 
AQ NUT DR 



FIG. 183. The pondweed mostly nut-like or drupe-like; seeds 1 in 

family, Zannichelliaceae. A, u rarnp l . Pn Hosr>prTn 

habit sketch of pondweed, eacn car P el > endosperm u. 

Potamogcton natans; B t a These curious and varied plants are 

nht; fl emb^yo C ' t * often ver y coiwpicuous in the submerged 
floral diagram (all after gardens of shallow water. Some of them 

0ralf0rillUlaf0r frc <l uentl y develop massive beds of tan- 
gled stems and leaves under such con- 
ditions. The principal genus of the family is Potamogeton, of 
which more than fifty species have been described. 

THE BUR REED FAMILY 

The members of the Sparganiaceae are reed-like plants with 
globular clusters of dry, more or less spiny and bur-like fruits 
(Fig. 184). They are aquatic or marsh herbs with perennial 
rhizomes and fibrous roots. The family is represented by a 
single genus and 30 to 40 species mostly of the temperate and 
cold regions of the Northern Hemisphere. 

Leaves alternate, linear, flat, more or less grass-like, sheathing 
at the base; flowers unisexual, crowded in globose heads at the 



ORDERS AND FAMILIES OF MONOCOTYLEDONS 



289 



nodes of the upper zigzag parts of the stem and branches, the lower 
heads being pistillate and the upper heads staminate; perianth 
or composed of a few chaffy scales; stamens several, usually 5, 
free or connate at the base; female flowers with membranous 
bracts, ovary sessile or pedicellate, one- or two-celled, ovule 1, 
style filiform, simple or forked; fruit one-celled, one-seeded, 
nut-like or drupaceaous. 

These plants are usually recognized among other marsh plants 
by the conspicuous bur-like globular heads of fruits arranged in a 
more or less zigzag series. 





CA CoS X5 P 1C2) 
AqNurDa F ^jfHiff c 

FIG. 184. FIG. 185. 

FIG. 184. Tho bur rood family, Sparoaniaccac. A, habit sketch of bur reed, 
Sparganium; B, a single carpel cut open; (7, fruit and seed; D, male flower of 
Spargamum; E, female flower (all after Rendlc}; F, floral formula for the family. 

FIG. 185. The cattail family, Typhaceae. A, leaf and clusters of female 
flowers (below) and male flowers (above) of cattail, Typha, greatly reduced; 
B, fruit; C, male flowers; D, cluster of female flowers greatly enlarged (all after 
Baillon); E, floral formula for the family. 

THE CATTAIL FAMILY 

This is the Typhaceae, a family with a single genus of 10 or 
more species of aquatic or paludose, perennial herbs with creep- 
ing rhizomes, fibrous roots, and smooth, erect, cylindrical stems 
(Fig. 185). They are widely distributed in temperate and 
tropical regions. They often grow in very dense communities. 

Leaves long, linear, flat, sword-like, distichous, sheathing at 
the base; flowers small, unisexual, densely crowded in long 
terminal spikes, the flowering shoot being a stiffly erect, cylin- 
drical shoot from the rhizome; staminate flowers subtended 



290 FLOWERS AND FLOWERING PLANTS 

by fugacious bracts covering the upper portion of the spike; 
pistillate flowers densely grouped in the lower portion of the spike, 
also subtended by a leafy bract that falls early; perianth com- 
posed of numerous bristles; stamens usually 3 (or more, 1 to 7), 
united at the base to a common filament; ovary stipitate, hairy, 
one- to two-celled, styles 1 or 2; both types of flowers accompanied 
by numerous bristly hairs which aid in dissemination; the pistil- 
late flowers mingled with numerous sterile flowers with clavate 
tips; fruit dry, nut-like; seed 1; endosperm abundant. The 
cylindrical cluster of brown, closely packed structures in the 
fruiting terminal spike of the cattail is usually conspicuous in 
fall and winter. This is sometimes used for decoration. 

THE SCREW-PINE FAMILY 

The Pandanaceae are a group of tropical shrubs or trees with 
peculiar spiral clusters of pineapple-like leaves at the tips of the 
main stem and branches. They are sometimes climbers and they 
then produce prop roots or stilt-like aerial roots. They are 
grouped in 3 genera and 400 species. They are widely distributed 
in the tropics of the Old World, especially in Malaya and in the 
Indian and Pacific islands. 

Leaves long and sword-like, stiff, in tufts at the ends of branches, 
arranged in three, spirally twisted series, edges and back of 
midrib with rows of spines; flowers in terminal panicles or spike- 
like clusters, unisexual, species sometimes dioecious, calyx 0; 
corolla 0; stamens few to many, free or connate; ovary one- to 
many-celled, indefinite, carpels more or less united, ovules 
several or single; stamens and pistils sometimes scattered over 
the axis without definite arrangement ; fruit a syncarp or a cluster 
of drupaceous fruits and more or less berry-like, often large. 

Several species of Pandanus are grown for ornamental purposes, 
and the leaves of P. utilis, a native of Madagascar, and other 
species yield fibers that are used for making baskets, fiber hats, 
and other useful articles. 



CHAPTER XXII 
THE LILIES, PALMS, AND AROIDS 

The members of this group of orders show many marks of 
advancement over the Alismales. They have become more 
widely and completely adapted to the land habit and their vegeta- 
tive anatomy is much more varied than that of the earlier group 
from which the Liliales have probably developed. The perianth 
is typically present (reduced in Arales and Palmales) and the 
ovary is tricarpellary and superior. 

ORDER LILIALES, THE LILY ORDER 

Flowers usually perfect and complete; calyx and corolla of 3, 
usually separate parts, commonly colored alike; stamens 6; 
ovary superior, tricarpellary; endosperm abundant. 

THE LILY FAMILY 

The Liliaceae or lily family (Fig. 186) are a very large and impor- 
tant family of herbs, shrubs, and a few trees and climbers of 
world-wide distribution, but with greatest abundance in tem- 
perate and subtropical regions. The family is here treated in 
the broad sense and as such it includes more than 200 genera 
and 2,500 species. The group is sometimes subdivided into 
several families or subfamilies in more extensive systematic works. 
The most of the species are perennial herbs which develop from 
bulbs, or bulb-like structures, or fleshy rhizomes; only a. few 
(Dracaena, Yucca) become woody and tree-like. 

Leaves exceedingly various, basal, in rosettes or alternate on 
a well-developed stem, usually simple, fleshy or dry and leathery, 
rigid and sharp pointed, ephemeral or evergreen; flowers often 
showy, or small and inconspicuous, single or in spikes, racemes, 
or panicles; the perianth of 6, more or less similar, petal- like 
parts or different (3 sepals, 3 petals), separate or united and six- 
lobed; stamens usually 6, sometimes 3, inserted on the axis 
opposite the segments of the perianth or attached to the tubular 
perianth; ovary tricarpellary, superior; 'ovules usually numerous, 

291 



292 



FLOWERS AND FLOWERING PLANTS 



fruit a capsule or berry, usually with many seeds; endosperm 
copious. 

The lily family is extremely rich in valuable plants that man 
uses for many purposes. Hundreds of species and varieties are 
in use as ornamentals including such well-known forms as 
tulips, Tulipa, Star of Bethlehem, Ornithogalum, mariposa, 
Calochortus, lily-of-the-valley, Convallaria, lilies, Lilium, such as 
Easter lily, L. longiflorum, tiger lily, L. tigrinum, Madonna 
lily, L. candidum, squills, Scilla, day lily, ffemerocallis, aloe, 
Aloe, hyacinth, Hyacinthus, etc. 




FIG. 186. Tho lily family, Liliaceae, A, a species of lily, Lilium (Mathews); 
R, flowers of Hyacinthus (after Baillon}; C, a plant of squill, Scilla (after Baillon}; 
/>, vertical section of a flower of hyacinth, Hyacinthus (after Baillon); E, floral 
diagram of fritillary, Fritillana (after Le M. and Dec.); F, floral diagram of 
asparagus, Asparaqnx (after Lc M. and Dec.); G, floral formula for the family. 

Useful vegetables included in the family are the onions and 
their immediate kin, Allium, and asparagus, Asparagus. The 
so-called " asparagus fern" is a true asparagus, A. plumosus, and 
not a fern at all. A. asparagoides is the common "smilax" of 
florists. 

THE SPIDERWORT FAMILY 

This family, the Commelinaceae (Fig. 187), includes about 26 
genera and 350 species of more or less succulent, annual and 
perennial herbs that are widely distributed and most abundant 
in the warmer parts of the earth, but are also seen in temperate 



THE LILIES, PALM 8, AND AROIDS 293 

climates, except temperate Europe and Asia. The stems are 
often nodular or knotty and leafy. 

Leaves alternate, entire, broad or narrow, sheathing at the 
base ; flowers in axillary clusters, perfect, actinomorphic or some- 
what zygomorphic, hypogynous; sepals 3, generally free, green; 
petals 3, free or united into a tube, commonly blue, withering; 
stamens usually 6, in 2 sets, or 3, staminodia often present, fila- 
ments free, often hairy; ovary two- to three-celled, superior, 
ovules many or few, style terminal, stigma capitate or slightly 
two- to three-lobed; fruit a capsule; endosperm copious. 




FIG. 187. The spidorwort family, Commclinaccac. A, leaves and flowers of 
spiel erwort, Tradeacantia (after Le M. and Dec..); B, floral diagram of Trades- 
cant La (after Le M. and Dec.); C, floral formula for the family. 

The spiderworts produce brightly colored blue flowers and so 
are popular potted or outdoor plants. The dayflower, Comme- 
lina coelestis, and C. tuber osa are beautiful Mexican species. 
The familiar Wandering Jew is Zebrina pendula, of which there 
are numerous cultivated varieties. The spider wort in a more 
restricted sense includes certain species of Tradescantia. A 
common spiderwort in America is T. virginiana or T. reflexa. 

THE PICKEREL WEED FAMILY 

The Pontederiaceae are a family of erect or floating, aquatic 
herbs that inhabit marshes and more or less quiet waters in 
warm regions and with a few species in temperate climates. 
Absent from Europe. The family includes 6 genera and about 
20 species. 

Leaves alternate, long petioled, blades floating, emersed or 
sometimes submerged, petiole sometimes dilated to form a blad- 
der, submerged leaves sometimes without blade; flowers perfect, 



294 



FLOWERS AND FLOWERING PLANTS 



hypogynous, actinomorphic or sometimes zygomorphic, usually 
spicate; perianth of 6 parts, petaloid, in 2 series (calyx and 
corolla), free or united to form a long or short tube; stamens 
3 or 6, on the tube or at the base of the perianth; ovary 
superior, three-celled, or one-celled with 3 parietal placentae; 
ovules numerous, style 1, stigma entire or three-parted; fruit a 
many-seeded capsule or an achene; endosperm mealy. 

The pickerel weed of the north is Pontederia cordata, a common, 
coarse herb with spikes of purplish flowers, seen in swampy 
areas. The water hyacinth, Eichornia crassipes, is a trouble- 
some aquatic or paludose weed with inflated petioles, common 
in tropical and subtropical America where it sometimes obstructs 
navigation in streams and small rivers. 



(Fig. 188). 



CA 3 Co 3 S 36 P a)0) 
CHAFFY FLAP 
c 



THE RUSH FAMILY 

Rushes in the botanical sense belong to the Juncaceae, but the 
term "rush" is often applied to many other plants in daily life 
These are annual or mostly perennial herbs with 
creeping, underground stems and 
grass-like nature and habits, com- 
monly found in moist places, 
marshes, etc., and often referred 
to as "grass." The family in- 
cludes 8 genera and about 300 
species of wide distribution 
throughout the temperate and 
cold portions of the earth. 

Leaves grass-like, often stiff and 
terete or sword-like, or chan- 
neled, leaf sheath with free 
margins, sometimes reduced to 
membranous sheaths; flowers 
small, perfect, actinomorphic, 
hypogynous, often borne in 
dense spikes or heads, sometimes loosely aggregated or single; 
sepals 3, petals 3, chaff-like, greenish or brownish; stamens 3 
or 6; ovary superior, three-celled, or one-celled with 3 parietal 
placentae, ovules many to 3, stigmas 3, fruit a capsule with 
many to few, often tailed, seeds, opening by 3 valves; endo- 
sperm starchy. 





FIG. 188. Tho rush family, Jun- 
caceae. A, flowering habit and 
single flower of a common rush, 
Juncus balticus; B, basal portion 
of stems of the same; (7, floral for- 
mula for the family. 



THE LILIES, PALMS, AND AROIDS 



295 



It is readily seen that the rushes are really grass-like lilies with 
small inconspicuous and chaffy flowers. They are of very little 
value. 

THE PIPEWORT FAMILY 

The family name for this curious and interesting group of 
Monocotyledons is Eriocaulonaceae (Fig. 189). They might 
be called the "monocotyledonous composites" on account of the 
flower clusters which resemble the heads of the true Compositae 
(Figs. 176 to 180). They are to be regarded as rather highly 
specialized lilies. The group includes 9 genera and 360 species of 
very wide distribution in the warmer and tropical parts of the 
earth and into temperate regions, 
the chief center being tropical 
South America. 

The pipeworts are aquatic and 
bog-inhabiting perennials with 
alternate, tufted, densely grass- 
like, basal leaves; flowers minute, 
unisexual (monoecious), in small, 
densely crowded, terminal head?, 
on long, slender scapes, the head 
subtended by a scaly, bracted 
involucre as in the Compositae, 
each flower in the axil of a scarious 
bract; sepals 2 or 3; petals 2 or 3, 
distinct or connate to form a tube; 
stamens 4; ovary two- to three 
celled, ovules 2 to 3, stigmas 2 to 
3, filiform; fruit a capsule, two- to 
three-celled; seeds 2 to 3; endo- 
sperm abundant, mealy. The staminate flowers are on the outer 
portion and the pistillate flowers are on the inner portion of the 
head or vice versa. 

The conspicuous genus of the family is Eriocaulon, meaning 
" woolly stem/' as noted in certain species. A species common 
to America and Europe is E. septangular -e. 

ORDER ARALES, THE ARUM ORDER 

The plants of this group, commonly known as the Aroids, 
typically produce small and inconspicuous flowers in dense 
clusters on a simple fleshy spike, spadix, which is subtended by 




r*v 
^ 



FIG. 189. The pipewort fam- 
ily, Eriocaulonaceae. /i, habit 
sketch of pipewort, Eriocaulon, 
septangulare; B, head of flowers; 
(7, floral diagrams, male flower 
at right, female flower at left; />, 
male flower with its bract, E, 
female flower; F, seed with mi- 
nute embryo; Gr, ovary showing 
pedulous ovules (all after Rendle) . 



296 FLOWERS AND FLOWERING PLANTS 

and frequently inclosed by a more or less showy bract, spathe, 
which constitutes the " flower" of gardeners. The flowers are 
perfect or unisexual; the perianth is reduced to scales or entirely 
lacking, never showy; the ovary is usually tricarpellary and 
superior. 

THE ARUM FAMILY 

The Araceae (Fig. 190) include perennial herbs, or they are 
sometimes more or less woody and tree-like, arising from a 
tuberous rootstock or corm; erect, prostrate or extensively 
climbing, sometimes epiphytic, of shady, damp or wet places; 
juice mostly acrid, sometimes milky. The family includes 




FIG. 190. The arum family, Ararsae. /I, arum, Aram italicum (after Ratlloti); 
J5, inflorescence of Jack-in-the-pulpit, Anwma triphyllum (after Le M . and Dec.); 
C, inflorescence of Arum (after Baillori); 2), floral formula for the family. 

about 100 genera and 1,500 species of cosmopolitan plants but 
developed in greatest number and most varied form in the tropics. 
Leaves extremely varied, mostly basal, long petioled, simple or 
compound, sword-shaped to hastate, entire or lobed, certain 
species (as of Monsterd) with large, regular holes in the blade; 
the flowers are densely aggregated on a fleshy spadix (spike), 
more or less surrounded by a showy bract the spathe, which is 
often conspicuously colored, and so constitutes the " flower" in 
a popular sense; flowers perfect or unisexual, some species dioe- 
cious, spadix very densely flowered, staminate flowers usually 
above, pistillate flowers below; sepals and petals lacking or of 4 
to 6 scaly parts, never showy; stamens many or reduced to 4 to 
10, or even to 1, filaments very short, often united; ovary supe- 
rior, 1- to 3-celled (one to several), ovules one or more in each cell, 
style short or wanting; fruit a berry, the cluster becoming enlarged 



THE LILIES, PALMS, AND AROIDS 297 

and densely grouped on the fruiting spadix; seeds few to many; 
endosperm present or 0. 

There are numerous Aroids of value as ornamentals and a few 
produce important foods. The best known ornamental is prob- 
ably the calla lily, Richardia aethiopica, a native of South Africa, 
and grown throughout the world. Others are the elephant ear, 
Colocasia esculenta, and the ceriman or "delicious monster/' 
Monstera deliciosa, with its large, perforated leaves. The 
dasheen, a variety of Colocasia esculenta, produces an abundance 
of large, globular or oblong tubers which are edible and for which 
the plant is sometimes cultivated. The common Jack-in-the- 
pulpit of North America, Arisaema triphyllum, is also a member 
of this family. t 

The duckweeds, Lemnaceae, are usually included in the Arales. 
These are minute, floating aquatics without leaves. The plants 
are small, globular, or flattish bodies bearing one to several 
or no roots, and extremely simple flowers consisting of 1 
tiny stamen and 1 pistil borne on the edge or upper surface of 
the thallus-like body. The duckweeds sometimes develop very 
thickly on the surface of shallow, quiet water. 

ORDER PALMALES, THE PALM ORDER 

The palms are mostly tropical trees or shrubs with variable form, 
but generally with stout, woody, and unbranched stem which ter- 
minates in a crown of large, evergreen, palmate or pinnate leaves. 
The flowers are very numerous and are borne in a large, compound 
inflorescence. The individual flowers are small, unisexual, and 
with inconspicuous perianth; ovary mostly tricarpellary. 

THE PALM FAMILY 

The Palmaceae (Fig. 191) include trees or shrubs of character- 
istic habit, but more variable than is commonly supposed, some 
of them being long, trailing, woody vines. They are usually 
erect, but some are climbing. The stems are slender and usually 
unbranched. The family includes about 140 genera and more 
than 1,200 species of general distribution throughout the tropics 
and extending somewhat into the warmer parts of the temperate 
zone. 

Leaves evergreen, stiff, often very large, usually palmate or 
pinnate, clustered in a dense, terminal crown; flowers small, 
mostly greenish, unisexual or perfect, usually in a huge, conspicu- 
ous, much branched spadix among the leaves; the spathe covers 



298 FLOWERS AND FLOWERING PLANTS 

the bud and it may become woody, but it does not inclose 
the mature inflorescence; sepals 3; petals 3, leathery or woody; 
stamens 6 (or more), rarely 3; ovary superior, three-celled, or 
sometimes the 3 carpels separate; fruit a one-seeded berry, drupe, 
or nut of various size and nature; seed usually 1, endosperm 
abundant, oily, or sometimes bony. 

The palms are very useful plants. Many of them are v widely 
planted in parks, lawns, and along drives in the tropics. Some of 
the ornamental species are: Chinese fanpalm, Livistona chinensis, 




FIG. 191. The palm family, Palmaceae. The datepalm, Phoenix dactylifera. 
A, cluster of fruits; B, pistillate flower, ^ront view; C, same, side view, D, stam- 
inate flower, front view (after F. Sargent); E, floral formula for the family. 

European fanpalm, Chamaerops humilis, royal palm, Roystonea 
rcgia, cabbage palm, Inodes palmetto, and various species and 
varieties of tho datepalms, Phoenix. The palm which furnishes 
the dates of commerce is P. dactylifera, of Africa and Asia, where 
it has been cultivated for 5,000 years. The coconutpalm, 
Cocos nucifera, is used for a great many purposes, the most 
important involving the use of the oily endosperm for food ; the 
fibers of the husk for ropes, mats, and brushes; the shells for uten- 
sils, and the leaves for thatching roofs. The rattan palms are 
species of creeping or climbing palms of the genera Calamus and 
Daemonorops, the slender stems of these plants sometimes reach- 
ing lengths of 600 feet. Raffia is a strong wrapping cord or tape 
made from the epidermis of Raphia ruffia, of Madagascar. 

The Palmales and Arales are regarded as highly specialized 
and modified lateral developments from the general type repre- 
sented by the Liliales. 



CHAPTER XXIII 
THE GRASSES AND SEDGES 

ORDER GRAMINALES, THE GRASSES AND SEDGES 

This order includes the grasses and the sedges, plants with 
herbaceous or woody shoots that are annual or perennial. The 
flat, linear leaves and tiny, reduced flowers produced in chaffy 
spikelets are characteristic of the group. The perianth is absent 
or represented by two or more very inconspicuous scales, the 
stamens are mostly 3 or 6, and the pistil is two- to three-carpelled 
but one-celled and with a single ovule; the fruit in the grasses is 
a grain or caryopsis, or rarely an achene. 

TluTgrasses are frequently regarded as having developed from 
some lily-like ancestral stork. Whatever may have been their 
origin, it is plain that they have become extremely modified 
and differentiated to such a degree that they have* been considered 
as the highest of all Monocotyledons by some students of the 
group, especially by Clements. 

THE SEDGE FAMILY 

The sedges, Cyperaceae, are grass- or rush-like herbs with solid, 
triangular, quadrangular, cylindrical or flattened stems and 
fibrous roots often arising from perennial rootstocks (Fig. 192). 
They are world wide in their distribution, being found under a 
great variety of natural conditions. The family includes about 
75 genera and 3,500 species, mostly of little economic worth. 

Leaves often in three ranks or longitudinal rows, sheaths usually 
closed around the stem, blade narrow; flowers perfect or unisexual, 
arranged in spikelets and the latter solitary or grouped in spike- 
like, or panicled clusters; each flower in the axil of a scale or glume, 
the latter in two ranks or imbricated, persistent, or deciduous; 
perianth of scales, or bristles or hairs, or wanting, rarely calyx- 
like; stamens generally 3, sometimes 2 or 1; filaments slender; 
ovary superior, two- to three-carpelled, one-celled, one-ovuled, 
style single, stigmas 2 or 3, more or less feathery; fruit an achene, 
often trigonous; endosperm abundant, mealy. 

299 



300 



FLOWERS AND FLOWERING PLANT8 



Several genera of sedges are widely represented throughout the 
world. More than 600 species of Cyperus, and 1,000 species of 
Car ex have been described. The paper plant of the Egyp- 
tians, the papyrus, is Cyperus papyrus, a native of Southern 
Europe, Africa, and Syria, and it is widely grown as an aquarium 
plant, as is its close relative, C. alternifolius, the umbrella plant. 
The bulrushes are species of Scirpus, of which there are many 
species recognized. 




FIG. 192. The sedge family, Cyperaceae. A and G, two species of Carex 
(after Baillon and Le M. and Dec.); B, pistillate flower of Carex (after Baillon), 
C, staminate flower of Carex (after Baillon); D, perfect flower of Scirpus (after 
Le M. and Dec.); E, staminate flower of another species of Carex (after Le M. 
and Dec.); F, perfect flower of Cyperus (after Baillon); //, floral formula for the 
family. 

THE GRASS FAMILY 

The commonest technical name fqfr the grass family (Figs. 
193 to 199) is Gramineae, but the group is also described under 
such names as Graminaceae, and Poaceae. The grasses are 
mostly erect, annual, or perennial herbs with fibrous roots, but 
some of them, as the bamboos, are distinctly woody and shrub-like 
or even tree-like. They usually develop conspicuously jointed, 
hollow stems. They exhibit 'a great variety of form and size, 
and some species or another is likely to be seen in almost every 
condition of soil and climate from the equator to far within the 
Arctic and Antarctic regions and from sea level to the tops of high 
mountains. Some of them are aquatic and others are character- 
istic of extremely arid and desert places. Grasses dominate 
vast expanses of territory in the prairies and plains of North 



THE GRASSES AND SEDGES 



301 



\merica, the pampas and llanos of Central and South America 
uad the steppes of Russia and the Balkan states. They are 
imong the most cosmopolitan of all flowering plants. The 
species are most numerous in the tropics but the abundance is 
greatest in temperate regions. The family includes about 400 
genera and 5,000 species. There are about 1,500 species of 
grasses in the United States, of which 140 are important native, 
wild, forage plants. About 60 species of grasses are cultivated in 
;.he United States. 

Loaves alternate, usually in two ranks, parallel veined, blade 
rften greatly elongated, attached to the node by means of a 




FIG. 193. FIG. 194. 

FIG. 193. The grass family, Gramineae. A, diagrammatic representation 
>f the structure of a grass spikelet with the two empty glumes and several 
[lowering glumes arid florets (after Chase); B, a grass flower, with stamens, 
pistil, and vestigial perianth (after Chase); C, floral diagram of rice, Oryza (after 
Le M. and Dec.); D, 4^al formula for the family; E, floral diagram of the oat, 
Avena (after Le A[. and Dec.). Ay 

P^IG. 194. A, generalized spflrelet of the grasses with two empty glumes and 
several florets (after Chase); B, a grass floret at flowering time, or when it is 
jpen (after Chase). 

sheathing base, the sheath usually open on the side opposite the 
blade and furnished with a membranous or hairy projection, the 
ligule, which is pressed against the stem at the point where 
the blade gives way to the sheath; blade and sheath smooth or 
more or less hairy; flowers (Figs. 193 to 199) tiny, chaffy, usually 
perfect, rarely unisexual (plants rarely dioecious) grouped in 
^pikelets (Figs. 193, 194, 195, 196, 197 and 198) each of which 
consists of a shortened, jointed and more or less zigzag axis, the 
rachilla (Figs. 193 and 194), bearing 2 to many two-ranked scales 



302 



FLOWERS AND FLOWERING PLANTS 



or bracts (Figs. 193 and 194), the lowest two (or rarely one) 
being empty, and, therefore called the "empty glumes" or merely 
the " glumes," and the one or many succeeding scales, the flower- 
ing glumes or "lemmas/' each bearing a flower in its axil, with 
another scale or bract (usually two-nerved), the palet or palea 
standing between the flower and the rachilla (Figs. 193 and 
194); this unit, composed of lemma, flower, and palea is called 
a "floret" (Figs. 193 and 194); each lemma may be sharp 
pointed or blunt, or in many cases the midrib is prolonged into a 
slender awn or beard, which is straight, twisted, or bent (Figs. 
195 and 196) ; the spikelet may be composed of one or many such 




FIG. 195. Different types of spikelets and flowers in grasses. A, spikelet 
of brome grass, Bromus ^ecahnus {after Cha^e); B, spikelet of wheat, Triticum 
(after Le M. arid Dec.}; C, single floret from the latter; />, side view of the spikelet 
of Proso, Pamcum mihaceum, E, dorsal view of samojtfa/fer Chase}; F, one- 
flowered spikelet of rice, Oryza *ativa (after BaMon); G^oint of spike of wild 
barley, Hordeum nodosum, with a cluster of sIpEslets (after Chase); //, spikelet 
of bluegrass, Poa pratensis (after Chase); /, spikelet of rye, Secale (after Baillori). 

florets arranged at the joints of the rachilla above the empty 
glumes, the uppermost ones sometimes being sterile; spikelets 
such as these are arranged in spikes, racemes, or panicles (Figs. 
197 to 199), the position of a single flower in other plants being 
occupied by a spikelet which may contain many flowers; they 
usually become dry and chaffy; the perianth is often lacking or is 
represented by two or three very delicate and usually incon- 
spicuous scales, lodicules (Fig. 193), at the base of the ovary inside 
the lemma and palea; stamens usually 3, sometimes 6, 2, or 1, 
free filaments very slender and hygroscopic; ovary superior, 



THE GRASSES AND SEDGES 303 

three-car pelled but usually one-celled and one-ovuled, styles 
1 to 3, usually 2, with plumose stigmas; fruit a caryopsis, i.e. a 
single-seeded dry fruit with thin pericarp which adheres closely 
to the seed (seed rarely free, as in Sporobolus)^oiten enveloped 
by the lemma and palea as in certain varieties of oats, barley, 
etc. the whole structure usually passing as a "seed," and indeed 
serving as such for practical purposes; endosperm starchy. 
The grass family is usually divided into two or more sub- 
families and these in turn into tribes, the most of which are quite 
distinctively marked. The following key will serve to illustrate 
the possibilities with reference to the separation of the different 
tribes as an aid in their classification. 

KEY TO THE TRIBES OF GRASSES 

A. Plants woody, aerial stems perennial; leaves with a joint between blade 
and sheath; spikelets with several florets Tribe Bambuseae, 

the bamboo grasses 

B. Plants herbaceous, aerial steins annual; leaves without a joint between 
blade and sheath; spikelets with several florets, or the latter reduced 
to one 

I. Spikelets more or less flattened laterally, jointed above the empty 
glumes, which are persistent after the rest of spikelet falls 

1. Spikelets with one to several florets, usually more than 1; 
inflorescence usually a spike 

a. Spikelets i|| two rows on opposite sides of the rachis, thus 

forming a Symmetrical spike Tribe Hordene, 

the barley grasses 

6. Spikelets in two rows on the same side of the rachis, thus form- 
ing a one-sided spike . . . Tribe Chlorideae, the grama grasses 

2. Spikelets with two to several florets, inflorescence usually an 
open or ^^tracte^yaanicle 

a. Empty glume(jpually shorter than the lemmas, and shorter 
than the spikelet as a whole; lemmas awnless, or with a 
straight terminal awn. .Tribe Festuceae, the fescue grasses 

b. Empty glumes longer than the lemmas, usually inclosing 
the whole spikelet; lemmas awnless, or with a bent dorsal 
awn Tribe Aveneae, the oat grasses 

3. Spikelets with one floret, or with 1 or more sterile lemmas below 
the fertile floret; inflorescence a panicle, or a raceme 

a. Spikelets with 2 sterile lemmas below the fertile floret, i.e. 
spikelet with 5 scales . . Tribe Phalarideae, the canary grasses 

b. Spikelets without sterile lemmas below perfect floret, i.e. 
spikelet with 3 scales. .Tribe Agrostideae, the timothy grasses 

II. Spikelets strongly flattened laterally, jointed below the empty 
glumes, the spikelet falling in its entirety, or empty glumes com- 
monly lacking Tribe Oryzeae, the rice j 



304 



FLOWERS AND FLOWERING PLANTS 



III. Spikelets round, or more or less flattened dorsally, usually jointed 
below the empty glumes, so that the spikelet falls as a whole 

1. Empty glumes membranous, lemma and palea hardened; spike- 
lets solitary Tribe Paniceae, the millet grasses 

2. Empty glumes hardened, at least firmer than the lemma and 
palea; spikelets in pairs v 

a. Both spikelets of the pair with perfect florets, or 1 sessile 
and perfect, the other pedicellate and perfect, staminate or 
sterile Tribe Andropogoneae, the sorghum grasses 

b. Spikelets unisexual, in separate inflorescences, i.e. plants 
monoecious . Tribe Maydeae, the maize grasses 

The grasses constitute the most important economic group of 
Monocotyledons, if indeed they are not the most valuable of all 
of the groups of flowering plants from this point of view. They 




Fio. 196. Spikelets that are more or less hairy, ^l^gpedgrass, Phraffmites 
commums (after Chase); B, little bluestem, Amjttpogon^fbparius (after Chase); 
C, sugar cane, Saccharum officinarum (after -^IHp*)' -^ blue grama, Bouteloua 
gracihs, empty glumes below, fertile lemma, Imd sterile lemmas above (after 
Chase). 



include the cultivated cereals with hundreds of varieties that 
furnish invaluable foods for man and beast, as well as many 
species that furnish varied materials for construction, and certain 
of them are used for ornamental purposes. The great grassland 
areas of the world constitute one of the most prominent features 
of the native vegetation of the earth. 

The bamboos, Tribe Bambuseae, are noteworthy on account of 
the perennial nature of their aerial stems which become tree-like 
in many species. The great bamboo of Malay, Dendrocalamus 
giganteus, reaches a height of more than 100 feet and a trunk 



THE GRASSES AND SEDGES 



305 



diameter of 6 to 10 inches. Extensive bamboo forests occur in 
Burma. The stems, leaves, and seeds of the bamboos are used 
for a great many purposes including food, in the daily life of the 
primitive and modern people of the regions where they grow. 
The barley grasses, Tribe Hordeae, include many species and 
varieties of wheat, Triticum, rye, Secale, barley, Hordeum, and 
many worthless weeds. Most of our cultivated varieties of wheat 
have been developed from a few original species. Thus Triticum 
sativum, has given rise to a long series of common wheat, club 
wheat, durum wheat, etc. Polish wheat is T. polonicum, and 
Poulard wheat is T. turgidum, the latter having been cultivated 




Fi. 197. Oat grasses. f^L, the panicle of spikelets of Avena (after Le M. and 
Dec); B, spikelet of wildfnKts, Avena fatua, entire spikelet; C, floret of same 
(after Chase); D, spikelet of Another wild oat, Truietum spicatum (after Chase); 
E, floret of cultivated oat, Avena saliva, with palea (after Le M. and Dec.). 

in Europe for 2,000 years. There are now several hundred named 
varieties and ra<(^of wheat known. Barley has been used as a 
cultivated plant smce p^Mptoric times. 

The grama grasses, Tnbe Chlorideae, are usually recognized by 
the one-sided spikes, or spike-like racemes in which the spikelets 
are borne. Prominent members of the tribe are Bermuda grass, 
Capriola dactylon, an Old World species, but introduced as a 
valuable lawn and pasture grass in southern United States; the 
grama grasses, about 30 species of Bouteloua, native to America 
and abundant in the southwestern states and Mexico; and the 
buffalo grass, Bulbilis dactyloides, another distinctive American 
species. Buffalo grass and several species of Bouteloua are 
among the world's most valued forage grasses. 

The fescue grasses, Tribe Fesluceae, include many valuable 
plants such as bluegrasses, species of Poa, orchard grass, Dactylis 



306 FLOWERS AND FLOWERING PLANTS 

glomerata, besides many species of fescue, Festuca, and brome 
grasses, Bromus. Meadow fescue, F. elatior, and awnless brome, 
B. inermis, are grown as pasture and meadow grasses. Worth- 
less and troublesome weeds also abound in this tribe, as F. octo- 
flora and B. lector um. 

The rice grasses, Tribe Oryzeae, are of immense value to man- 
kind mainly because of a single species, Oryza sativa, with its 
several cultivated varieties. Rice is native to the East Indies, 
but is now widely grown in many countries, especially in China 
where it forms about one-half of the food of the people. Rice 
culture in China is known since 3,000 B. c. The plant was intro- 
duced into the United States in 1694 and it now forms an impor- 
tant crop in the southern states, especially in Louisiana. The 
grain of American wild rice, Zizania aquatica, was used by the 
Indians in the early day. This coarse plant grows in wet places 
in northern United States and Canada. 

The oat grasses, Tribe Aveneae (Fig. 197), include other 
economic plants that have been cultivated in Europe since pre- 
historic times. The common oat is Avena sativa, of which there 
are many cultivated varieties which supply valuable food for 
man and domesticated animals. Foods prepared from the grain 
of oats are prominent articles of diet in the United States, 
England, Scotland, and Ireland. Oat eyjasses may often be 
recognized by the bent, dorsal awn on th^emmas. 

The canary grasses, Tribe Phalarideae, are usually recognized 
by the two sterile, or staminate florets between the empty glumes 
and the one perfect floret in the spikelet. The grass that is 
grown in Europe for birdseed is Phalaris canaj^msis. American 
canary grass, P. arundinacea, is a flneHHhr pla^r for the southern 
states. Ribbon grass is a variety of trfflatter species, P. arundi- 
nacea, var. picta, which produces leaves that are striped with 
white and yellow. Sweet vernal grass, Anthoxanthum odoratum, 
produces fragrant herbage. Vanilla grass, Savastana odorata, 
is a native of northern Europe and America, the leaves of which 
are very fragrant, and are often woven into mats and baskets 
and used in trimming boxes, baskets, and other articles in which 
the sweet, lasting odor is desired. 

The timothy grasses, Tribe Agrostideae (Figs. 198 and 199), 
include some of our most valuable forage and pasture grasses, 
with many wild species in cool climates. The inflorescence in 
these grasses is sometimes a densely flowered spike, or spike-like 



THE GRASSES AND SEDGES 



307 



panicle. Timothy or cattail grass, Phleum pratense (Fig. 198), 
is the most important hay plant of cultivated meadows in the 
north where it is extensively naturalized. Mountain timothy, 
P. alpinum, is found in the mountains of North America. Red- 
top grass, Agrostis alba, is an important hay grass. Beach grass 
or marram grass, Ammophila breviligulata, is a prominent plant 
of coastal dune areas of eastern North America and Europe, 
and it has often been used for planting as a sand binder. Species 
of Stipa are included in the flora of prairies and plains of America 
and Europe. The needlegrass (Fig. 199, E, F) of America is 
S. spartea, or <Sf. comata. 





FIG. 198 FIG. 199. 

FIG. 198. Timothy. A, the spike of Phleum pratense; B, empty glumes 
and floret of same; C, basal part of plant (after Hitchcock); D, a single spikelet 
of timothy (after ^B^) _ 

FIG. 199. Redt^Jp^, U^fcifiorescence of Agrostis alba; B, spikelet; C, 
basal part of stem and rhizoHp (after Hitchcock); D, spikelet of Calamagrostis 
canadensis, floret raised abo^Rho glumes (after Chase); E, needlegrass, Rtipa 
spartea, empty glumes at left; F, floret with its long, twisted awn at right (after 
Chase). 

The millet grasses, Tribe Paniceae, are widely distributed and 
include many important species. The genus Panicum includes 
about 400 species, most of which are of little value. Crab 
grass, Digitaria sanguinalis, is a troublesome lawn pest. The 
familiar sandbur is Cenchrus pauciflorus, and the foxtail grasses 
are species of Chaetochloa. Millet or Hungarian grass is C. 
italica, with several varieties that are valuable cultivated 
forage plants in America, but in Europe the seed is often used for 
human food. Pearl millet is Pennisetum glaucum, also grown 



308 FLOWERS AND FWWERING PLANTS 

for forage and grain, especially in Africa; feather grass, P. villosum 
and P. ruppelii, are grown as ornamentals, particularly as border 
plants. 

The sorghum grasses, Tribe Andropogoneae, are a large group in 
warm climates particularly, but with certain species well repre- 
sented in temperate regions. The most important plant of the 
tribe is sugar cane, or simply cane, Saccharum officinarum, a 
coarse, perennial grass with a woolly, plume-like panicle. This 
plant is one of the principal sources of cane sugar for which it is 
grown in all tropical countries. The cultivated sorghum is 
Holcus sorghum, of which there are four principal series of varie- 
ties, Sorgo, the forage and saccharine sorghums of many varieties 
grain sorghums, Kafir, Dura, Milo, Shallu, etc. Hay Sorghums, 
Johnson grass, Sudan grass, etc. and broom-corn sorghums, of two 
or more types. Some of the members of this tribe are also highly 
prized ornamentals in warm countries. These include Ravenna 
grass or pampas grass, Erianthus ravennae, of southern Europe, 
and Eulalia, Miscanthus sinensis, of Asia, both of which produce 
large, beautiful, plume-like flower clusters. Zebra grass is Mis- 
canthus sinensis, var. zebrinus, called this because of the transverse 
bands of white or yellow that mark the leaves. The bluestem 
grasses of the Mississippi valley are species of Andropogon, includ- 
ing A. furcatus and A. scoparius. ^ 

The Maize or "corn" grasses, TribGrnmaydeae, are also of 
tremendous economic value because of tcilrEndian corn or maize 
>f America, Zea mays, which is not now known in the wild state. 
This plant has been grown from Peru to central North America 
since prehistoric times and it is today one o^|ke world's most 
important field crops. It may be notflfcy^at 9M plant is known 
in Europe as maize or Indian corn, whWas "corn" there is likely 
to be what is known in America as wheat or barley. A great 
many named varieties of maize have been described, and are 
now in cultivation. Some of the more important or interesting 
varieties or groups of varieties are dent corn, var. indenta, pop- 
corn, var. everta, flint corn, var. indurata, pod corn, var. tunicata, 
zebra corn, var. japonica, sweetcorn, var. saccharata. The curious 
teosinte, Euchlaena mexicana, sometimes thought to be the ances- 
tor of maize, and Job's-tears, Coix lacryma-jobi, also belong here. 



CHAPTER XXIV 
THE WATER WEEDS, IRISES, AND ORCHIDS 

EPIGYNOUS MONOCOTYLEDONS 

This subclass includes the higher orders and families of Mono- 
cotyledons. They are among Monocotyledons somewhat similar 
to the Resales- Aster -ales line among the Dicotyledons. The axis 
of the flower in this series is normally expanded into a cup, and 
this cup-shaped receptacle bears the perianth and stamens on 
the rim, or the stamens are attached to the perianth in certain 
forms. The carpels are usually united and are more or less 
deeply imbedded in the receptacle below the insertion of perianth 
and stamens, i.e. the carpels or the ovary are inferior. The 
flowers here are actinomorphic, or zygomorphic, exhibiting 
extremely bizarre and varied, irregular forms in the Orchids. 

ORDER HYDRALES, THE WATER WEED ORDER 

This small g rou P^tf aquatics is characterized by diclinous, 
actinomorphic flowei^M which the tricarpellary ovary is inferior, 
and these are more or less inclosed by or surrounded by a bracted 
involucre or spathe. The latter feature may pos^ityly indicalSi 
a relationship %jth the Amies. The order is here regarded as 
another reduc^^^^teral^evelopment from the region of the 
Liliales. A single f ainVHs follows: 

THE TAPEGRASS FAMILY 

This family, the Vallisneriaceae, includes 14 to 15 genera and 
about 50 species of floating or submerged herbs of wide distribution 
in both fresh and salt water in warm and temperate climates. 
They develop so luxuriantly sometimes as to choke streams and 
canals with their more or less stringy forms. 

Leaves various, simple, linear, lanceolate, or rounded kidney- 
shaped, submerged or floating, often crowded at the base of the 
stems; flowers actinomorphic, usually dioecious or polygamous, 
rarely perfect, more or less inclosed by a spathe of 1 to 3 bracts, 

309 



310 FLOWERS AND FLOWERING PLANTS 

or leaf -like scales; sepals 3; and petals 3, usually present; sepals 
and petals distinguishable or all petaloid, borne on the margin 
of the receptacle, sometimes tubular; stamens 3 to 12, separate or 
more or less united, inserted on rim of axis or on the perianth 
tube; ovary inferior, three-carpelled, but one-celled, or three- 
celled, ovules several, style 3, with entire or two-cleft stigmas; 
fruit leathery or fleshy, ripening under water; seeds numerous; 
endosperm 0. 

These plants are sometimes cultured in aquaria and fish bowls. 
The water weed or water thyme, Elodea canadensis, is frequently 
seen in such places. The frogsbit, Hydrocharis morsus-ranae, a 
plant with rosettes of long-pet ioled leaves with rounded and 
heart-shaped blades is ajso grown in aquaria. 

ORDER IRIDALES, THE IRIS ORDER 

This is a rather large group containing about a dozen families 
of land plants of diverse habit. The flowers are epigynous, i.e. 
the ovary is inferior, the perianth is actinomorphic and composed 
of free, or united parts, and the seeds are supplied with endo- 
sperm. The order is derived from the upper Liliales and repre- 
sents a distinctly higher type than the lilies. The irids are 
distinguished from the lilies, which they resemble in habit and 
mode of life, largely by the inferior ovar^jprhich is seen in prac- 
tically all of the Iridales. 

THE AMARYLLIS FAMILY 

This, the Amaryllidaceae, is a large family^Hig. 200) mostly 
of perennial, bulbous herbs, or witMfcps 9M leaves arising 
from rootstocks, of very diverse habit^RFt often resembling lilies 
and, in fact, they are frequently confused with the lilies. The 
family includes about 70 genera and 800 or more species that 
inhabit the warm and temperate portions of the world, but more 
largely developed in South America, South Africa, and the Medi- 
terranean region. 

Leaves alternate, narrow, entire, radical or cauline; flowers per- 
fect, regular or nearly so, usually one or more borne on a leafless 
scape subtended by 2 or more bracts; sepals 3; petals 3, separate, 
inserted on a tubular receptacle, sometimes with 3 additional inner 
parts that are corolla-like, sometimes with a cup-shaped or tubu- 
lar " crown" (Narcissus) resembling an additional corolla tube, 



THE WATER WEEDS, IRISES, AND ORCHIDS 



311 



inserted outside the stamens; stamens 6, inserted on the throat 
or at the base of the axis segments, separate; ovary inferior, 
three-celled, ovules often numerous, style filiform, entire, lobed or 
three-divided at the tip; fruit a capsule or sometimes berry-like; 
seeds black, endosperm fleshy. 

This family is rich in highly prized ornamentals grown as pot 
plants inside or planted in lawns or parks out of doors. Among 
such plants may be mentioned the belladonna lily, Amaryllis 
belladonna, Knight star, Hippea8trum reginae, swamp-lily, Crinum 
americanum, snowflake, Leucojum vernum, snowdrop, Galanthus 




FIG. 200 -The amaryllis family, Amaryllidaceae. 

cissus, Narcissus poeticus; B, single flower of N. jaeimltKarcriasus; C\ section of 
flower of Narcismisf I), section of narcissus flower with long tube; E, floral for- 
mula for the family; F, floral diagram of Hypoxis (after Le M. and Dec.). 



nivalis, spider-lily, HyijbnocalUs americana, and the narcissuses, 
the genus Narcissus, intruding poet's narcissus, N. poeticus, with 
a shallow, red-bordered crown,. paper- white narcissus, N. tazetta, 
the daffodil or trumpet narcissus, N. pseudonar cissus, and the 
jonquil, N. jonquilla. 

The family also includes the American aloe or century plant, 
Agave americana, of Mexico and Central America, and widely 
cultivated in warm countries. About 300 species of Agave have 
been described. Sisal hemp is prepared from A. sisalana. 
The intoxicating liquors known as mescal and pulque are prepared 
from the juice of certain agaves. 



312 



FLOWERS AND FLOWERING PLANTS 



THE IRIS FAMILY 

The irises, or "flags" as they are often called in America (Fig. 
201), are included in the family Iridaceae along with about 60 
other genera and a total of 1,000 or more species of herbs of 
world-wide distribution in temperate and tropical regions. 

Leaves mostly basal, equitant, two-ranked, linear or sword- 
shaped, arising from roo$|tocks, tubers or corms; flowers usually 
showy, terminal or paniculate, perfect, actinomorphic or some- 
what zygomorphic, emerging from a spat he of 2 or more 
bracts; perianth of 6 parts in 2 series, the 3 outer ones (sepals) 
often petal-like, all 6 parts usually inserted at the top of a more 




FIG. 201. The iris family, Iridaceae. A, a single flower of iris, Iris (after 
Kaillori); B, vertical section of a flower of Iris (after Baillori); C, floral formula 
{ floral diagram of Iris (after Le M. and Dec.]. 



or less tubular receptacle above the ovary; stamens 3, separate 
or united; ovary three-celled, inferior, Style single, the 3 stigmas 
sometimes expanded and colored to resemble another set of 3 
petals; ovules numerous; fruit a dehiscAt, three-angled capsule 
with many seeds; endosperm fleshy or Mirny. 

The iris or fleur-de-lis family includes many of the most 
popular, cultivated ornamental plants known. This is reflected 
in the mere mention of the irises, the crocuses, the freesias, and 
the gladioluses. The genus Iris comprises about 700 named 
species and varieties, many of which produce gorgeous flowers. 
Iris florentina produces the orris root of commerce. There are 
also hundreds of species and cultivated forms of Gladiolus. 
Species of Crocus are also popular plants on account of their large, 
showy flowers. The saffron crocus is C. sativus, a fall-blooming 



THE WATER WEEDS, IRISES, AND ORCHIDS 313 

species of southern Europe, whose dried, orange-colored stigmas 
constitute the saffron of commerce. It is said that it requires 
more than 4,000 flowers of this plant to produce 1 ounce of 
saffron. The cldth-of-gold crocus of the Crimea is C. susianus. 

THE PINEAPPLE FAMILY 

The Bromeliaceae are a family composed of about 40 genera and 
1,000 species of caulescent or acaulescent, more or less scurfy 
herbs that are often epiphytic, and somewhat shrubby plants 
mostly native to tropical America. Certain forms are widely 
introduced into other warm countries for ornamental purposes 
and for food production. 

Leaves commonly in rosettes, elongated, sword-like, with scaly 
or smooth, entire or spinulose margin and overlapping or sheath- 
ing base; flowers perfect, actinomorphic, in dense spikes or heads 
with colored and showy bracts, or in less showy panicles; sepals 
3, petals 3, free or united to form a tubular perianth with erect 
or spreading lobes; stamens 6, at base of the perianth; ovary 
inferior (or semisuperior) , or superior, three-celled, ovules many, 
style filiform, three-lobed or three-parted ; fruit a berry or capsule, 
more or less surrounded or crowned by the persistent calyx ; seeds 
small, hairy or winged; endosperm copious, mealy. 

The pineapple, Ananas sativa, is the most valuable economic 
plant of this family. The "fruit" of this plant is a fleshy, 
multiple fruit or syncarpium formed from the enlarged axis of the 
spike, densely covered by the spirally arranged ripened ovaries 
and adherent parts, all enlarged and more or less grown together 
to form the oval or elongated " pineapple" of the market. The 
true fruit, or one of the aborted ovaries in the surface, is a seedless 
berry. Florida "moss" or "long moss", Tillandsia usneoides, 
a strikingly different type of plant, is often seen in characteristic 
streamers and festoons on the trees of southeastern United 
States. This plant is sometimes used for stuffing upholstered 
furniture. 

THE BANANA FAMILY 

The Musaceae are the banana family (Fig. 202). The group 
includes 6 genera and more than 60 species of large perennial 
herbs, sometimes more or less woody, widely distributed through 
the tropics of both hemispheres. The so-called banana "tree" 
(Fig. 202, A) is really only an erect stem or branch from a huge 



314 



FLOWERS AND FLOWERING PLANTS 



rhizome or underground rootstock. This erect stem is composed 
mostly of the long, stiff, and overlapping leaf sheaths. The erect 
shoots die after they bear the bananas. 

Leaves simple, often very large, 6 feet or more long, entire, 
pinnately veined, with rolled and overlapping sheaths; flowers 
zygornorphic, perfect, or monoecious, borne in spikes or panicles 
which are subtended by spathes and the flower clusters often 
in the axils of large and showy bracts (Fig. 202, B); sepals 3, 
free or united; petals 3 or fewer, free or united, the outer one 
larger than the others; stamens 6, but 1 of these is sterile, all 
free; ovary inferior, three-celled, ovules numerous or only one, 




FIG. 202. The banana family, Musaccae. A, greatly reduced sketch of a 
banana "tree"; B, a bract with a cluster of flowers, (7, single flower; D, leaves of 
traveler's tree, Ravenala (all after ftendle}; E, floral formula for the family. 

style simple, stigma capitate or three- to six-lobed; fruit a berry or 
capsule, dehiscent or indehiscent, or separating into the 3 carpels; 
seeds few to many, hard, often with an aril; endosperm mealy. 
The banana which furnishes most of the fruit of commerce is 
Musa sapientum, a form in which the seeds are aborted. These 
are produced in large quantities in the plantations of Central 
America. Many other species and varieties are known, some 
of which produce large seeds as in Musa ensete, the Abyssinian 
banana. Another species, M . textilis, is widely cultivated, espe- 
cially in the Philippine Islands for the fiber, Manila hemp, which 
is secured from the leaf bases. The curious traveler's tree (Fig. 
202, D) of Madagascar is Ravenala madagascariensis, a striking 
ornamental on account of the immense leaves that are arranged in 



THE WATER WEEDS, IRISES, AND ORCHIDS 315 

2 ranks at the top of the stem in such a manner as to give the 
crown a fan-like appearance. The bird-of-paradise plant of 
South Africa is Strelitzia reginae, also a member of this family. 

THE GINGER FAMILY 

This is the Zingiberaceae, a family of 40 genera and more than 
400 species of perennial herbs with creeping or tuberous root- 
stocks and short, simple stems. They are nearly all tropical, 
being found in both hemispheres, but most numerous and abun- 
dant in tropical Asia. 

Leaves simple, petiolate or sessile, sheathing, entire, linear, 
lanceolate, or broader, radical and cauline, ligule prominent; 
flowers perfect, zygornorphic, in heads, bracted spikes, or pani- 
cles; perianth in 6 parts, calyx tubular, three-toothed; corolla 
tubular, unequally three-lobed; stamens 6, but only 1 is func- 
tional, the others sterile and sometimes broad and petal-like 
(staminodia) ; ovary inferior, three-celled or one-celled, with 3 
axile placentae, ovules many, style and stigma 1, the slender 
style held in a groove in the fertile stamen; fruit a capsule; seeds 
many; endosperm present. 

Commercial ginger is prepared from the aromatic, creeping, 
thick-jointed, branching rootstocks of common ginger, Zingiber 
officinale, of Asia and New Guinea. Some of the gingers are also 
grown for ornamental purposes as in ginger lily, Hedychium 
coronarium. 

Other families that are more or less closely related to those 
that have been included in this order are the Cannaceae, the 
cannas, Dioscoreaceae, the yams, and the Marantaceae, the 
arrowroots. 

ORDER ORCHIDALES, THE ORCHID ORDER 

This is an enormous group of extremely varied plants with 
world- wide distribution and the most -extreme floral differentia- 
tion, commonly regarded as the highest of all Monocotyledons. 
The order includes two families, the Burmanniaceae, with a dozen 
genera and about 60 species with mostly actinomorphic flowers, 
and the Orchidaceae, a vast family with varied, zygornorphic 
flowers (Fig. 203) which really stamp the order as an outstanding 
group. The flowers are usually perfect, corolla extremely 
zygornorphic, with 3 sepals and 3 petals, stamens 2 or 1, ovary 
inferior and usually tricarpellary, but one-celled. The most 



316 



FLOWERS AND FLOWERING PLANTS 



varied flower forms and detail of floral mechanism known are 
found in this group in which entomophily has apparently played 
the leading r61e. 

THE ORCHID FAMILY 

This is the Orchidaceae, a family (Fig. 203) of probably more 
than 500 genera and 15,000 species of low, erect, sprawling or 
climbing herbs of very wide distribution in temperate and trop- 
ical regions throughout the world. Besides the ordinary 
terrestrial forms there are many epiphytic and even saprophytic 
species known. They are perennials with bulbous, tuberous, 
or thickened, fleshy stems and roots and extremely varied stem 
form. 




FIG. 203. The orchid family, Orchidaceae. A, single flower of orchid, Phal- 
aenopitia, front view (after Kerner); B, front view of single flower of Epipactis 
(after Kerner); C, single flower of Orchis; Z), floral diagram of Orchis; E, single 
flower of lady's slipper, Cypripedium; F, floral diagram of Cypripedium (after 
Baillori); G, floral formula for the family. 

Leaves usually alternate, simple, entire, thin, or often thick 
and more or less fleshy, linear, oblong, or orbicular; flowers from 
the base of the plant or from the axils on leafy stems or terminal, 
often very showy because of size or color, often grotesquely 
irregular (Fig. 203) and oddly splotched in the cultivated species, 
but small, greenish and inconspicuous in many other species; 
usually perfect, sometimes heteromorphic; sepals 3, usually 
narrow and not showy; petals 3, the 2 lateral ones similar in 
form and coloration, the third forming a lip of different shape and 
color which is extremely varied as to form and color, sometimes 
spatulate or saccate, and often spurred, all of these parts free 



THE WATER WEEDS, IRISES, AND ORCHIDS 317 

and attached to the rim of the receptacle above the ovary (Fig. 
203); stamens and pistil united to form an unsymmetrical 
gynandrium or column composed of 1 (or 2) fertile stamens in 
which the anther alone with its 2 to 8 masses of pollen is present 
and this is grown to the style, the pear-shaped, stalked masses 
of pollen known as "pollinia" (Fig. 203, A) and these united by 
strongly elastic threads, the masses powdery or waxy, and 
attached at the base to a glandular disk; style often ending in a 
beak, the rostellum, at the base of the anther or between the 
anther cells; stigma viscid, facing the lip, under the rostellum or 
in a cavity (clinandrium) between the anther sacs; ovary inferior, 
three-celled, or one-celled and three-angled, usually long and 
twisted, ovules numerous, on 3 parietal placentae ; fruit a capsule; 
seeds very small, very numerous, seed coat loose, reticulated; 
endosperm none. 

A great many orchids are grown by florists and others for 
their large, showy flowers of great variety of color and form. 
Some of the popular types of ornamental orchids are as follows: 
Cattleya labiata, with a more or less tubular lip of varied color in 
the different varieties, Odontoglossum crispum, with a lobed 
and toothed lip, Oncidium varicosum, and Epidendrum vitellinum. 
The lady's slipper or moccasin flower of the woods is Cypripedium 
(Fig. 203, E) of which several species with purple and yellow 
flowers are known. The fringed orchid of meadows and prairies 
is Blephariglottis ciliata. Extract of vanilla is prepared from the 
pods of certain orchids, especially Vanilla planifolia and V. 
pompona. The former species is a climbing epiphyte with fleshy 
leaves and it is often cultivated for the crop of fruits from which 
vanilla is obtained. The flowers of vanilla are commonly hand- 
pollinated in the plantations in areas outside of Mexico where the 
pollinating bees do not occur. 



CHAPTER XXV 



A BIT OF EARLY HISTORY 

Men have puzzled over the origin, nature, and classification of 
plants since ancient times. Very early agricultural and medical 
demands stimulated an interest in plants and led to attempts to 
name and classify them. 

WORK OF THE ANCIENTS 

Numerous writers of ancient times described certain general 
plant characteristics and cataloged many of the more evident 
properties of plants. Thus Theophrastus (372-287 B.C.), the 

immortal Athenian, and later 
Dioscorides, Galen, and Pliny, 
about the beginning of the 
Christian era, were among the 
most important writers on 
botany of antiquity. Theo- 
phrastus was a pupil of Aris- 
totle (384-322 B.C.) who had 
been a pupil of Plato (426- 
347 B.C.) and he described 
about 450 cultivated plants, 
and classified them as herbs, 
under shrubs, shrubs, and trees. 
Theophrastus considered trees 
to be the very highest expres- 
sion of plant development 
and he placed them at the 
top of the plant world. He 
ARISTOTLE (384-322) .-(Photo furnished noted fhe Difference between 

by Brooklyn Botanic Garden.) . 

centripetal and centrifugal 

inflorescences. Nearly twenty centuries later Linnaeus wrote 
of Theophrastus as the " father of botany/' as indeed he 'had 
been known long before that time. Dioscorides prepared a 
"Materia Medica" but his descriptions are so meager and 

318 




A BIT OF EARLY HISTORY 



319 



his classification so crude as to be of little value. Pliny wrote 
nine books on useful plants in which he presented many 
details for the cultivation of certain plants for their gums and 
spices. 

The Middle Ages. The good work that had been done by 
Theophrastus and his contemporaries was lost and forgotten for 
many centuries following their time. Little was accomplished 
in the classification of plants, 
or in fact with reference to 
anything else, during the long 
and chaotic period of the Dark 
Ages and the Middle Ages 
until about the beginning of 
the sixteenth century. 

THE TIME OF THE HERBALS 

With the sixteenth century 
came a period known in the 
history of botany as the time 
of the herbals. This period, 
which lasted for about 200 
years, was characterized by a 
renewed enthusiasm for the 
study of plants among Ger- 
man, French, Belgian, and 
Dutch botanists, along with 
the general revival of learn- 
ing. Such 'men as Fuchsius (1501-1566) (or Fuchs, after whom 
Fuchsia or" "fushia" is named), Bock (1498-1554), Brunfels 
(1500-1534) and Clusius (or de TEclus, 1526-1609) wrote much 
about plants at that time. The invention of printing and the 
introduction of printed books at about the same time made the 
preservation of their work possible. 

The principal object of the plant classifications and descrip- 
tions that these men published was to enable interested persons 
to identify medicinal plants. Many of their drawings and 
descriptions were little if any better than those left by the 
ancients, thus reflecting the terrible stagnation that resulted 
from the long period of intellectual inactivity that had inter- 
vened. Fuchs arranged an alphabetical classification. Bock 
(Hieronymus) contended that natural similarity of form should 




THKOPHRAKTI h (372-287). (Photo fur- 
nished by Brooklyn Botanic Garden:) 



320 



FLOWERS AND FLOWERING PLANTS 



be considered in the separation of plants into different groups, 
and he appears to have sensed something of natural affinities, 
but he fell into the common practice of the period when he made 
his major groups herbs, shrubs, and trees. Centuries before this 
Theophrastus had grouped plants into trees, shrubs, undershrubs, 
and herbs as clearly defined classes, and he also made certain 
further subdivisions within these classes. It would seem that these 
earlier herbalists should have contributed much more than they 

did toward the development 
and advancement of more 
adequate schemes for the 
nomenclature, classification, 
and description of plants 
when they inherited so much 
of value from Aristotle, 
Theophrastus, and the other 
natural philosophers of their 
time. Certain modern his- 
torians tell us that many of 
the plant descriptions pre- 
pared by the herbalists "are 
almost word for word trans- 
lations of- the ancient para- 
graphs of Theophrastus" 
and others. 

Workers in Southern 
Europe. Ce sal pi no (or 

Caesalpinus, 1519-1603), the Italian physician, and one of the 
herbalists, is sometimes credited with the promulgation of the first 
real and important classification of plants. He recognized the 
importance of the seed and the fruit, and his arrangement of plants 
in fifteen classes is based largely upon these structures. The influ- 
ence of the Aristotelian school is seen in his two major groups as 
trees and shrubs, and undershrubs and herbs, but he went further 
and divided the first group into two classes and the latter into 
thirteen classes on the basis of fruits and seeds. Little or no 
hints of phyletic relationships are seen in Cesalpino's classifica- 
tion, however. It would seem strange, with his attention to 
fruits and seeds, that he did not stumble upon some of the 
characteristics that have come to be used to separate Dicotyle- 
dons and Monocotyledons. Cesalpino was still impressively 




ANDREA CESALPINO (1519-1603). (Photo 
furnished by Brooklyn Botanic Garden .) 



A BIT OF EARLY HISTORY 



321 



imbued with the ancient scholasticism and philosophy, which 
fact probably interfered more or less with his understanding of 
the true nature of plants. 

Dawn of Binomial Nomenclature. The writings of C. Bauhin 
(1550-1624), a Swiss, about the same time are noteworthy of the 
vigorous attempt to pull away from the type of reasoning that 
had come down from antiquity. He set himself the task of 
clearing away the confusion that had persisted for so many 
centuries. The fact that he 
made considerable advance in 
this endeavor is mirrored in 
the frequent use of binomial 
nomenclature. He utilized 
this method with such fre- 
quency and consistency that 
he might, indeed, be credited 
with the introduction of this 
important tool of systematic 
botany. He described many 
plants with a generic and 
specific name, but this ten- 
dency was varied now and 
then by the introduction of a 
third or even a fourth name. 
His great work the " Phy to- 
pi nax" of 1596 is a note- 
worthy contribution in which 
he states that clearness in 
botanical writing is to be secured only by applying one name to 
each plant. Many of the descriptions of plants in Bauhin 's 
works are much like modern descriptions of species, and his 
groupings often reflect relationships, but this was probably more 
accidental than intentional. He still held to the doctrine that 
shrubs and trees are the most specialized plants irrespective of 
the floral features in which he apparently did not sense indica- 
tions of affinities. A belief in a progressive development from 
simpler to higher is reflected in Bauhin, as in several other 
men of his time, but their attempts to express this belief in an 
arrangement or classification of plants usually shows great 
uncertainty and inconsistency in the distribution of the various 
forms. 




CASPAR BAUHIN (1550-1624). (Photo 
furnished by Brooklyn Botanic Garden.) 



322 FLOWERS AND FLOWERING PLANTS 

Certain Groups of Plants Recognized. M. de TObePs (or 
Lobelius, 1538-1616) principal contributions were of considerable 
merit because he pointed out very clearly that leaves are of 
great value in a general scheme of plant classification. On the 
basis of leaf characteristics he differentiated two groups in which 
we can readily recognize Dicotyledons and Monocotyledons 
in about their modern forms. He clearly recognized certain 
natural affinities in plants. A very interesting and valuable fea- 




MATHIAS L>B LOBDL (1538-1616). JOHN RAY (1628-1705). (Photo fur- 
(Phcto furnished by Brooklyn Botanic nished by Brooklyn Botanic Garden.) 
Garden.} 

ture of TObePs great work, the " Krnydtboeck " of 1581, is 
found in the many excellent illustrations which it contains. 
These old wood engravings were so carefully prepared and the 
reproductions so well done that the plants illustrated are very 
readily recognized. 

THE FOUNDATION OF MODERN BOTANY 

Toward the close of this period, i.e., late in the seventeenth 
century and the beginning of the eighteenth century, there 
appeared a number of important workers whose contributions 
laid the foundations of modern botany. John Ray (1628-1705), 
an Englishman, shares preeminently in the great advancement 
of botany that began during these years which in reality mark the 



A BIT OF EARLY HISTORY 323 

close of the herbals and the beginning of modern botany. Ray's 
most important work was the "Historia plantarum" (1686-1704) 
in which "the first germ of the natural system " is said to occur. 
He clearly sensed the importance of the monocotyledonous and 
dicotyledonous nature of the embryo from the standpoint of 
relationship and classification. But the shades of antiquity 
appeared again, at this late date, in "Herbae" and "Arbores" 
that constituted the main divisions of his classification. He 
uses the terms Dicotyledons and Monocotyledons for the first 
time, and he divides these into many classes some of which 
show natural affinities as we understand them today, but others 
are badly jumbled. He used many binomial names especially 
in descriptions of grasses. The main subdivisions in Ray's 
classification are as follows: 

I. Herbae: 

A. Imperfecti (flowerless) 

B. Perfecti (flowering) 

Dicotyledons (with two cotyledons) 
Monocotyledons (with one cotyledon) 

II. Arbores: 

A. Monocotyledons 

B. Dicotyledons 

It is worthy of note, in passing, that Ray was also greatly 
interested in vegetable physiology, as well as in systematic botany. 
One volume of his "Historia" is devoted to this branch of our 
subject, and in it he described some of his own experiments on the 
ascent of sap. 

The Demonstration of Sexuality in Flowers. Carnerarius, a 
German (1665-1721), should be mentioned because of the fact 
that he was the first to demonstrate sexuality in the flowering 
plants by experiment. Very little had been learned about this 
important phenomenon from the time of Theophrastus until 
Carnerarius began his experiments in the last decade of the seven- 
teenth century. He proved by experiment that pollen is abso- 
lutely necessary for fertilization and the formation of seeds in the 
normal life history of plants. His first experiments were per- 
formed on herb mercury, Mercurialis annua, Euphorbiaceae, 
but he also worked with the mulberry, Morus, nettle, Urtica 
romana, castor bean, Ricinus, maize, Zea, spinach, Spinacia, and 
hemp, Cannabis. 



324 



FLOWERS AND FLOWERING PLANTS 



Tournefort and the Genus. Tournefort (1656-1708) was 
among the very last to classify plants as herbs, shrubs, and trees. 
His most valuable contribution is in the careful delimitation of 
many genera of plants. He is sometimes referred to as the 
"founder" of genera. His efforts in that direction stand in 
contrast to those of many of his contemporaries whose main 
effort was with species. Generic names had been used before 
him, but Tournefort was the first to provide genera with descrip- 
tions and thus to set them 
definitely apart from spe- 
cies. Tournefort also 
directed attention to the 
value of the corolla in 
classification. He used the 
expressions Petalodes and 
Apetali to distinguish those 
flowers with and those 
without petals, respec- 
tively. He has been crit- 
icised somewhat for his dis- 
regard for specific differ- 
ences within the genera, 
but certainly his efforts to 
definitive a larger group, 
the genus, mark an im- 
portant epoch in the his- 
tory of classification. 




JOSEPH P. I>K Toi KNKIOI- 
1708). (Photo furmshcd hy 
Botanic Garden.) 



i ( 1 056 - 
Brooklyn 



LINNAEUS AND HIS WORK 

Linnaeus, (or Carl Linne*) the great Swede, and the father of 
modern botany, was born in 1707, the year before Tournefort 
died. Botanical lore was so rapidly improved and greatly 
expanded by Linnaeus and his contemporaries that botanical 
science has continued to advance from that day to this. Botany, 
indeed all science and culture, will profit forever from the inspi- 
ration that flows from the contemplation of the vigorous and 
varied life and the very extensive work of this great man with 
whom modern botany began. 

Linnaeus did much to revise and reorganize botanical nomen- 
clature and he employed the binary system of naming plants to a 
degree that is not seen in the writings of any of his predecessors. 



A KIT OF EARLY HISTORY 



325 



He described hundreds of plants from many parts of the world, 
including many from North America. He revised many of the 
older genera and gave great stability to species. 

The Basis of the System of Linnaeus. But, master though he 
was, Linnaeus was not prepared to bring out a classification of 
plants based on natural relationships. His sexual system was a 
tremendous advance over anything that had been done in system- 
atic botany before his day, but that system is largely artificial, 
although he seemed to recog- 
nize that a natural system of 
classification was highly de- 
sirable. His classification was 
based upon the number of 
stamens (24 classes) and pistils 
(67 orders) in flowers, and it 
became at once very popular 
because it readily enabled 
men to classify the plants 
that came to their attention. 
The sixty-seven orders of 
Linn6 were groups of genera 
that he designated natural 
orders. It was quite impos- 
sible for him to define the 
various orders critically, but 
it is a noteworthy fact that 
the beginnings of numerous 
natural groups are seen that 
have come to have a lasting status in modern systems of classi- 
fication. The outline of the system was given in his "Systema 
Naturae" in 1735, and again in "Genera Plantarum" in 1737, 
along with a systematically diagnosed and arranged collection 
of all genera known at that time. 

The System Proposed by Linnaeus. The twenty-four classes 
in the system of Linnaeus were differentiated on the basis of 
stamen characters. The outline of the system so far as classes 
are concerned, with examples of the various classes is as follows: 




CARL VON LINNE or LINNAEUS 
(1707-1778). 



KLASS 1. Monandria: stamens one. 

Duckweed, Lemna, samphire, Scdicomia, bulrush, Srirpus, chick- 
weed, Stellaria. 



326 FLOWERS AND FLOWERING PLANT* 

KLASS 2. Diandria: stamens two. 

Peppergrass, Lepidium, speedwell, Veronica, ash, Fraxinus, sage, 
Salvia. 
KLASS 3. Triandria: stamens three. 

Iris, Iris, cleavers, Galium, valerian, Valeriana, water duckweed, 
Montia. 
KLASS 4. Tetrandria: stamens four. 

Plantain, Plantago, whitlow grass, Draba, dogwood, Cornus, elm, 
Ulmus, mint, Mentha. 
KLASS 5. Pentandria: stamens five. 

Primrose, Primula, mullein, Verbascum, touch-me-not, Impatiens, 
borage, Borago, mousetail, Myosurus. 
KLASS 6. Hexandria: stamens six. 

Barberry, Berberis, dock, Rumex, wator-plantam, Alisma, calla, 
Calla, starflowor, Tnentalis. 
KLASS 7. Heptandria: stamens seven. 

Horse-chestnut, Aesculus, starflower, Trientahs. 
KLASS 8. Octandria: stamens eight. 

Certain heaths, Ericaceae, evening primroses, Onagraceae, and 
buckwheats, Polygonaceae. 
KLASS 9. Enneandria: stamens nine. 

Rhubarb, Rheum, buttercup, Ranunculus. 
KLASS 10. Decandria: stamens ten. 

Flax, Linum, maple, Acer, agrimony, Agrimonia, certain heaths, 
Ericaceae, and pinks, Caryophyllaccae. 
KLASS 11. Dodecandria: stamens eleven to nineteen. 

Mignonette, Reseda, calla, Calla, buttercup, Ranunculus, spurge, 
Euphorbia. 
KLABS 12. Icosandria: stamens twenty or more, attached to the calyx 

(axis). 

Rose, Rosa, bridal wreath, Spiraea, blackberry, Rubus, dry as, 
Dryas, and other members of the rose family, Rosaceae. 
KLASS 13. Polyandria: stamens twenty or more, attached to the axis. 

Linden, Tilia, bancberry, Actaea, poppy, Pa paver, larkspur, 
Delphinium, and certain waterlihes, Nymphaeaceac. 
KLASS 14. Didynatma: stamens didynamous. 

Verbena, Verbena, twin flower, Lmnaea, certain mints, Labiatae, 
and snapdragons, Scrophulariaceae. 
KLASS 15. Tetradynamia: stamens tctradynamous. 

The mustard family, Cruciferae. 
KLASS 16. Monodelphia: stamens in one bundle. 

Flax, Linum, mallows, Malvaceae, goosefoots, Chenopodiaceae, 
geraniums, Geraniaceae. 
KLASS 17. Diadelphia: stamens in two bundles. 

Certain poppies, Papaveraceae, and many legumes, Leguminosae. 
KLASS 18. Polyadelphia: stamens in several bundles. 

Linden, Tilia, St. John's-wort, Hypericum. 
KLASS 19. Syngenesia: stamens with united anthers. 

Nightshade, Solanum, lobelia, Lobelia, violet, Viola, and most 
composites, Compositae. 



A BIT OF EARLY HISTORY 



327 



KLASS 20. Gynandria: stamens grown to the pistil. 

Birthwort, Aristolochia, and orchids, Orchidaceae. 

KLASS 21. Monwcia: plants momecious. 

Duckweeds, Lemnaceae, cattail, Typha, arrowhead, Sagittaria, 
pigweeds, Amaranthaceae, mulberry, Morus, oak, Quercus, beech, 
Fagus, birch, Betula, hazel, Corylus, and arborvitae, Thuya. 

KLASS 22. Dicecia: plants dioecious. 

Nettle, Urtica, willows, Salix, cottonwood, Populus, hemp, 
Cannabis, ash, Fraxinus, juniper, Juniperus. 

KLASS 23. Polygamia: plants polygamous. 

Maple, Acer, crowberry, Empetrum, many composites, Compositae, 
goosefoots, Chenopodiaceae, and umbellifers, Umbelliferae. 

KLASS 24. Cryptogamia: flowers concealed. 

Plants without flowers such as ferns, mosses, fungi and algae. 

The orders into which the Klasses were divided were named 
according to the nature of the ovary. We find, for instance, 




LINNAEUS in LAPP COSTUME. 



under Klass 2, Diandria (2 stamens) the following orders: 
Ordnung 1, Monogynia; Ordnung 2, Digynia; Ordnung 3, 
Trigynia; Ordnung 4, Tetragynia; to include plants with pistils 
or styles that correspond more or less closely to the condition 
inferred in the order names. Klass 14, Didynamia, included 
two orders, namely Gymnospermia and Angiospermia. The 
gymnosperms according to this classification did not embrace 



328 FLOWERS AND FLOWERING PLANTS 

the plants that are now included in that group, but they were 
made up largely of the mints, Ldbiatae, and snapdragons, 
Scrophulariaceae. 

Odd Combinations. Many odd features are noted as we look 
over this brief synopsis of the system, and in the light of modern 
information concerning the phyletic relationships of plants we 
are able to point out many inconsistencies such as the placement 
of Myosurus, Borago, Quercus, and Sagittaria in the same groups. 
The two classes that stand out most nearly as we know flowering 
plants today are Klass 15, Tetr adynamia, or the mustards, 
Cruciferae, and Klass 12, Icosandria, which includes many roses, 
Rosaceae. It is interesting to note that Linnaeus was puzzled by 
the axis or "calyx-cup" problem among the roses and related 
forms. 

Value of the Work of Linnaeus. Linnaeus taught that "the 
foundation of botany is two-fold: classification and nomen- 
clature. " On the whole the system of classification and nomen- 
clature that Linnaeus gave us is a truly remarkable one when we 
consider the relatively few" plant characteristics that were 
employed in making it. If he had only hit upon the greater 
value of a larger number of characters he doubtless would 
have introduced a system that would be in use to this day. 
But that is probably expecting too much from even one of the 
world's greatest men at a time when civilization had only lately 
emerged from a long period of superstition and almost impenetra- 
ble darkness. 

For many years after Linnaeus the measure of a botanist was 
largely determined by the number of species of plants that he 
knew. The stimulation of his remarkable accomplishments 
reached into all lands and greatly accelerated the accumulation of 
enormous stores of reliable information concerning the flora (and 
fauna as well) of the world. 



CHAPTER XXVI 
FROM LINNAEUS TO ENGLER AND BESSEY 

The invigoration that followed the Linnaean period soon took 
form in many countries in the rapid expansion and specialization 
of various branches of science. Advances in chemistry and 
physics about that time contributed greatly to the development of 
sane points of view and to the formulation of logical hypotheses in 
physiology that rapidly laid the foundations of present-day knowl- 
edge of plant and animal behavior. Improvements in the 
microscope and in technique brought a knowledge of the finer 
details of plant structures that was truly astounding. But most 
of all there came into men's minds a keen sense of a scientific 
spirit which more and more cried out for experimentation and 
careful reasoning. Thousands of new plants had been described 
from all parts of the world and a knowledge of plant-life histories 
and details of development were greatly extended. The natural 
consequence of those advances had greatly extended the interest 
in systematic botany and botanists were beginning to see more 
clearly their way toward the development of a natural system 
of classification which would be helpful for purposes of identi- 
fication and at the same time would reflect something tangible 
concerning relationships. 

THE NATURAL SYSTEM FOUNDED 

Contributions of B. and A. L. de Jussieu. Two Frenchmen, 
Bernard de Jussieu (1699-1777) and his nephew, A. L. de Jussieu 
(1748-1836), near the close of the eighteenth century worked out 
a scheme of classification that was based upon the sexual system 
of Linnaeus, but it was a great improvement over the best that 
the Swedish master had accomplished. B. de Jussieu made many 
changes and rearrangements in the system of Linnaeus so that he 
really worked out a plan of classification that was essentially new 
and his own but he never published it. The nephew, A. L. de 
Jussieu, modified the plan of his uncle still further and published 
it along with his own scheme in 1789. A. L. de Jussieu's "Genera 

329 



330 



FLOWERS AND FLOWERING PLANTS 



Plantarum" in which he published his classification gives us an 
arrangement that is in reality a much more nearly natural sys- 
tem than was that of Linnaeus. This man is commonly given the 

credit of founding the natural 
system. He included fifteen 
classes and these were divided 
into one hundred orders which 
were clearly differentiated and 
described for the first time. 
So that, with de Jussieu, 
botanists had rather clearly 
distinguished species, genera, 
orders, and classes. These 
"orders" have become 
approximately the families in 
modern systems of classifi- 
cation. Many of de Jussieu's 
orders (families) are to be 
recognized in the most mod- 
ern classifications. This is a 
tribute to the care with which 
he did his work and the keen 
insight which marked his 
contributions. The general plan o/ his system is indicated by the 
following extract: 




A. L. DB JUSSIEU (1748-1836). (Photo 
furnished by Brooklyn Botanic Garden.) 



ACOTYLEDONBS ClaSS I 

{Stamina hypogyna Class II 
Stamina perigyna Class III 
Stamina epigyna Class IV 

DlCOTYLEDONES 

f Stamina epigyna . . . : . Class V 

Apetalce < Stamina perigyna Class VI 

[ Stamina hypogyna. . Class VII 

Corolla hypogyna Class VIII 

Corolla perigyna Class IX 

Monopetalce f Antheris connatus Class X 

Corolla epigyna < 

[ [ Antheris distinctis Class XI 

f Stamina epigyna . , . Class XII 

Polypelalce < Stamina hypogyna Class XIII 

[ Stamina perigyna Class XIV 

Diclines irregulares Class XV 



FROM LINNAEUS TO ENGLER AND BESSEY 331 

He included all of what we understand today as thallophytes, 
bryophytes, and pteridophytes as well as a few puzzling flowering 
plants (Naiadales) in Class I coordinate with the flowering 
plants. 

Certain Families Recognized. At that late date it was impos- 
sible to arrange the forms below the flowering plants into any 
sort of a natural system because of a lack of information about 
them. That task is extremely difficult, except in connection with 
the larger groups, even today after a century of refinement 
in microscopic tcchnic. Such familiar groups as grasses, Gramin- 
eae, and sedges, Cyperoideae, were included in Class II. Class III 
contains palms, Palmae, asparagus, Asparagus, lilies, Lilia, 
pineapples, Bromeliae, irises, I rides, and narcissuses, Narcissi. 
In Class IV we find bananas, Musae, cannas, Cannae, and orchids, 
Orchides. Class VIII includes a long list of orders (families) 
such as nightshades, Solanaceae, mints, Labiatae, borages, 
Boraginaceae, morning-glories, Convolvuli, phloxes, Polemonia, 
and gentians, Gentianeae, about as we understand the group today. 
Many other family names, still familiar entries in our manuals, 
are noted in the various classes of his system. 

Monographs of Families. These illustrations are sufficient to 
indicate clearly that de Jussieu's system of classification clearly 
foreshadows the schemes that were proposed by later workers of 
the modern school of systematic botanists. The men who came 
after him improved the classification mainly by drawing some- 
what clearer or more definite lines between the groups. His 
ideas of relationships among the flowering plants were far in 
advance of any that had been promulgated up to his time. He 
spent many years on working out more careful characterizations 
of the orders (families) since he believed that the development of a 
rational natural system depended upon a careful diagnosis of 
these groups. For many years after his time the popular line of 
work was to prepare monographs of families. He published 
several such monographs himself, notably on the Ranunculaceae. 

INFLUENCE OF DE CANDOLLE 

The Scheme of de Candolle. de Jussieu did the most of his 
work in Paris. Another great Frenchman, A. P. de Candolle 
(1778-1841) contributed a very suggestive system of classification. 
He spent much time in Paris and Montpellier in his younger years 



332 



FLOWERS AND FLOWERING, ftLANTS 



but after 1816 he lived in Geneva, Switzerland, where his bril- 
liance of intellect and his broad interests outside as well as within 
science contributed much to mark that city as a notable center 
of natural science and culture. He wrote many monographs of 
plant families and he was also greatly interested in physiology 
and plant geography. His "Theorie elemcntaire de la botanique" 

was published in 1813, and 
in this he developed his 
theory of classification and 
laid down the laws of classi- 
fication in such an improved 
and definite manner as to 
establish the natural system 
for all time. Naturally, he 
was greatly aided in this work 
by the quantity of material 
that had been accumulating 
for a century dealing with the 
morphology of flowering 
plants. He pointed out the 
value and the necessity of a 
knowledge of the detailed 
morphology of plant organs 
A. P. DECANDOLLE (1778-1841). (Photo if the most perfect natural 

furnished by Brooklyn Botanic Gar den.) c l assificat i on is tO be made. 

The plan of de Candolle's system as published in 1819 is as 
follows: 






I. VASCULARES: Plants with vascular bundles, or plants with 

cotyledons. 

Class 1. EXOGENAB. Exogens or Dicotyledoneae; vessels arranged in a 
"ring" or in concentric layers; the embryo with two cotyledons. 
A. DIPLOCHLAMYDEAE : Flowers with a double whorl of perianth parts, 
i.e., calyx and corolla both present. 
a. THALAMIFLORAE: Polypetalous and hypogynous. 

Cohort 1. Carpels many or stamens opposite the petals. 
Orders 1 to 8 Ranunculaceae, Nymphaeaceae, Berberidaceae, etc. 

Cohort 2. Carpels solitary or joined; placentae parietal. 
Orders 9 to 20. Cruciferae, Cistaceae, Violaceae, etc. 

Cohort 3. Ovary solitary, placenta central. Orders 21 to 44. 
Caryophyllaceae, Geraniaceae, Malvaceae, etc. 

Cohort 4. Fruit gynobasic. 
Orders 45, 46, Simarubeae, etc, 



FROM LINNAEUS TO ENGLEH AND BESSEY 333 

b. CALYCIFLOBAE: perigynous or epigynous, stamens on the calyx; 
includes certain gamopetalae. 

Orders 47 to 84. 

c. COROLLIFLORAE: gamopetalous and hypogynous, stamens 
epipetalous. 

Orders 85 to 108. The hypogynous gamopetalae. 

B. MONOCHLAMYDEAE: flowers with a single perianth whorl, i.e. calyx 
only present. 

Orders 109 to 128 

Class 2. ENDOGENAE. Endogens or Monocotvledorieae; vascular bundles 
scattered, not arranged m a ring; the embryo with a single cotyle- 
don. 
A. PHANEROGAMAE: Flowers present, i.e., visible and regular. 

Orders 129 to 150, 
H. CRYPTOGAMAE: Flowers absent, hidden or unknown. 

Orders 151 to 155. 

II. CELLULARES: Plants without vascular bundles or without 
cotyledons. 
Class 1. FOLIACEAE Leafy; sexuality known 

Orders 156 to 157 (mosses, liverworts) 

Class 2. APHYLLAK. Not leafy; .sexuality unknown or uncertain. 
Orders 158 to 161 (algae, fungi, lichens) 

The orders in de Candolle's system, like those of de Jussieu, 
are more nearly the families of our modern books on classification. 
This system contains 161 such orders, de Jussieu J s 100, and that 
of Linnaeus 67. The last edition of de Candolle's "Theorie 
elementaire, " published in 1844 by Alphonse de Candolle (a son), 
contained 213 orders or families. 

Work in England. An interesting point noted in all these 
systems of classification, including de Candolle's, is that the pines 
and their kin (Coniferae, Cycadae, etc.) are distributed among 
well-defined groups of dicotyledonous flowering plants in a more 
modern sense. Robert Brown, an Englishman, was the first to 
point out (in 1827) that those plants really have naked ovules 
and seeds and so should be excluded from flowering plants 
proper, or at least be given a special group by themselves. 
Brown's researches indicated that the Gymnosperms must be 
regarded as a separate and independent group. 

Lindley (1799-1865), an Englishman, designed a system of 
classification that is of great interest because of its influence in 
England and elsewhere. Lindley's work has been severely 
criticised and belittled in certain quarters, especially in Germany, 
but his work contributed greatly to the clarification of the 
principles involved in a natural system of classification in spite of 



334 FLOWERS AND FLOWERING PLANTS 

the fact that his proposals are often inconsistently represented in 
his classification. 

On the Continent. Stephen Endlicher (1804-1849) was 
another prominent systematist of the first half of the nineteenth 
century. That was a period rich in suggestions as to classifica- 
tion and many systems were proposed. Endlicher's scheme of 
classification was published in his " Genera Plantarum secundum 
Ordines Naturales disposita" in 1836-1840 and it was widely 
used by the countries of continental Europe. The general 
nature of the system is shown in the following synopsis: 

REGIO I. Thallophyta. Plants without true string and roots, tracheary 

vessels, arid sex organs. 
Sectio I. Protophyta 

Class I. Algae-aquatic 
Class II. Lichens-aerial 
Sectio II. Hysterophytn 

Class III. Fungi 
REGIO II. Cormophyta. Plants with true sterns and roots, vessels; s<x 

organs for the most part present. 

Sectio III. Acrobrya. Stems with apical growth only. 
Conors 1. Anophyta 
Class IV. Hepaticae 
Class V. Musci 
Cohors 2. Protophyta 
Class VI. Equiseta 
Class VII. Fihces 
Class VIII. Hydroptendes 
Class IX. Selagines 
Class X. Zamtae 
Cohors 3. Hysterophyta 

Class XI. Rhizarithae 
Sectio IV. Amphibrya. Stems with cylindrical growing zone. 

(Here are mostly monocotyledons, distributed in Classes XII 
to XXII, with 34 orders.) 
Sectio V. Acramphibrya. Stem with both apical and cylindrical 

growing zones. Here are conifers and dicotyledons. 
Cohors 1. Gymnospermae 

Class XXIII. Coniferae, with four orders. 
Cohors 2. Apetalae. Perianth lacking or simple. 

Class XXIV to XXIX, with 36 orders. 
Cohors 3. Gamopetalae. Perianth with calyx and corolla, petals 

united, rarely absent. 
Classes XXX to XXXIX, with 45 orders 
Cohors 4. Dialypetalae. Perianth with calyx and corolla, petals free, 

hypogynous, perigynous or epigynous, rarelv absent. 
Classes XL to LXII, with 116 orders. 



FROM LINNAEUS TO ENGLER AND BESSEY 



335 



Curious notions regarding stem growth extant at the time are 
reflected in the terms for the three sections of Cormophyta in 
Endlicher's system. The list of orders (families) that we find 
under the various classes are much the same as those that appear 
in de Candolle's works. Many of them are in use today with 
about the same inclusions that occur in this system. The dif- 
ficulty of disentangling the Gymnosperms from the Angiosperms 
is also evident in Endlicher's plan, as it is in several prominent 
systems that were proposed 
long after his day. 

The Frenchman, Brong- 
niart, published a system of 
classification in 1843 that is 
interesting in that he drops 
out the Apetalae as a definite 
group. He indicates that 
these are imperfect forms of 
petaliferous types and so he 
distributes such species among 
the orders of Dialypetalae. 
Systematists are not agreed 
even yet as to what the 
Apetalae really are and so 
their treatment is still uncer- 
tain. It seems, however, that 
there is a growing tendency to 
regard them as reduced 
forms and to distribute 
them among the orders to 
which they appear to be related on other grounds, as Brongniart 
suggested. 

The Classic System of Bentham and Hooker. An important 
system of classification that appeared during the last half of the 
nineteenth century was that of Bentham and Hooker. George 
Bentham (1800-1884) and Sir Joseph Hooker (1817-1911) were 
two Englishmen whose researches were greatly enhanced by the 
rapidly growing collections of plants at the great herbarium of the 
Royal Botanical Garden at Kew. Sir Joseph Hooker was 
director of the Garden for twenty years, following the death of his 
illustrious father, Sir W. J. Hooker. Bentham and Hooker's 
system, containing 202 orders (families), was published in a 




JOSEPH DALTON HOOKER (1817-1911). 
(Photo furnished by Brooklyn Botanic 
Garden.} 



336 FLOWERS AND FLOWERING PLANTS 

monumental work, " Genera Plantarum" (1862-1883), the 
most popular plant classification in European countries except 
France for many years. It was used in practically all of the 
early botanical work in the United States where it held undis- 
puted preference until the Engler system came out near the 
close of the century. This system reflects many of the features 
of the systems of de Jussieu and de Candolle, but it stands out 
as a very marked improvement over those and other schemes of 
classification that had been proposed previously. The arrange- 
ment of groups in Bentham and Hooker follows de Candolle 
rather closely but the English investigators appear to have 
recognized the possibility of the ie reduced nature " of the Apetalae, 
rather than that the plants of that group are primitive. The 
general plan of Bentham and Hooker's system, in brief synopsis, is 
indicated below, with a few illustrative orders (families) under 
each series. 

A. DICOTYLEDONS 

I. Polypetalae. Petals separate. 

SERIES I. THALAMIFLORAE. Hypogy nous, stamens and pistils many, 
indefinite, mostly free. 

Cohort 1. Ranales, Orders: Ranunculaceae, Magnoliaceae, Anona- 

ceae, Berberideae, etc. 
Cohort 2. Parietales. Orders: Papaveraceae, Cruciferae, Reae- 

daceae y Violaceae, etc. 

Cohort 3. Polygalineao. Orders: Polygaleae, etc. 
Cohort 4. Caryophyllineae. Orders: Caryophylleae, Portula- 

caceae, etc. 
Cohort 5. Guttiferales. Orders: Hypericaceae, Guttiferaceae, 

Dipterocarpeae, etc. 

Cohort 6. Malvales. Orders: Malvaceae, Tiliaceae, etc. 
SERIES II. DISCIFLORAE. Hypogynous, calyx usually free from ovary, 
stamens usually definite, receptacle often expanded as a disk, ovary 
free or imbedded in the disk. 

Cohort 7. Geraniales. Orders: Lineae, Geraniaceae, Rutaceae, 

Meliaeeae, etc. /**"* 

Cohort 8. Olacales. Orders: Olalineae, Ilicineae, etc. 
Cohort 9. Celastrales. Orders : *Celastrineae, Rhamneae, Ampe- 

lideae, etc. 
Cohort 10. Sapindales. Orders: Sapindaceae, Anacardiaceae, 

etc. 

SERIES III. CALYCIFLORAE. Perigynous, ovary enclosed by the axis, 
sometimes inferior. 

Cohort 11. Resales. Orders: Leguminosae, Rosaceae, Raxi- 
frageaej Crassulaceae, etc. 



FROM LINNAEUS TO ENGLER AND BES8EY 337 

Cohort 12. Myrtales. Orders: Myrtaceae, Lythracae, Onagraceae, 

etc. 
Cohort 13. Passiflorales. Orders: Loaseae, Passifloreae, Cucur- 

bitaceae, Begoniaceae, etc. 

Cohort 14. Ficoidales. Orders: Cactaceae, Ficoideae. 
Cohort 15. Umbellales. Orders: Umbelliferae, Araliaceae, 

Cornaceae. 

II. Gamopetalae. Petals united. 

SERIES I. INFEHAE. Ovary inferior, stamens as many as lobes of the 
corolla, rarely fewer. 

Cohort 1. Kubiales. Orders: Rubiaceae, Caprifoliaceae. 
Cohort 2. Asterales. . Orders: Valerianae, Dipsaceae, Calycereae, 

Cotnpoidtae. 

Cohort 3. Campanales. Orders: Campanulaceae, etc. 
SERIES II. HETEROMERAE. Ovary usually superior, carpels more than 
two, stamens as many as or fewer than corolla lobes, epipetalous or 
free. 

Cohort 4. Ericales. Orders: Ericaceae, Vaccinieae, Mono- 

tropcae, Epacrideae, etc. 

Cohort 5. Primulales. Orders: Printulaceae, etc. 
Cohort 6. Ebon ales. Orders: Ebenaceae, Sapotaceae, Styraceae. 
SERIES III. BICARPELLATAE. Ovary usually superior, carpels usually 
two, rarely 1 or 3; stamens alternate with the corolla lobes, and equal 
in number or fewer. 

Cohort 7. Gentianales. Orders: Oleaceae, Apocynaceae, etc. 
Cohort 8. Polemoniales. Orders: Polemoniaceae, Solanaceae, etc. 
Cohort 9. Personales. Orders: Rcrophularineae, Bignoniaceae, 

Acanthaceae, etc. 
Cohort 10. Lamiales. Orders: Verbenaceae, Labiatae, etc. 

III. Monochlamydeae. Perianth simple, often sepaloid or wanting. 

SERIES I. CURVEMBRYEAE. Embryo curved; endosperm mealy; 
ovule usually single; flowers perfect, commonly apetalous; stamens 
equal to or fewer than perianth divisions. 

Orders: Nyctagineae, Amarantaceae, Chenopodiaceae, etc. 
SERIES II. MULTIOVULATAE AQUATICAE. Submerged herbs; carpels 
united. Ovules numerous. 

Order: Podostemaceae. 

SERIES III. MULTIOVULATAE TERRESTRES. Terrestrial herbs and 
shrubs. Carpels united. Ovules numerous. 
Orders: Nepenthaceae, Aristolochiaceae, etc 

SERIES IV. MICREMBYEAE. Embryo ver> small, imbedded in 
copious endosperm. Carpels separate or united. Ovules usually 
solitary. 

Orders: Piperaceae, Mynsticeae, etc. 

SERIIS V. DAPHNALES. Ovary usually of one carpel. Ovules 
solitary. Perianth sepaloid. Mostly trees and shrubs with perfect 
flowers. 

Orders: Laurineae, Proteaceae< Elaeagnaceae, etc. 



338 FLOWER! AND FLOWERING PLANTS 

SERIES VI. ACHLAMYDOSPOREAE. Pistil one-celled. Ovules one to 
three. 

Orders: Loranthaceae, Santalaceae, etc. 

SERIES VII. UNISEXUALES. Flowers unisexual. Pistil simple or 
syncarpous. Ovules solitary or in pairs. Perianth sometimes 
lacking. 

Orders: Euphorbiaceae, Urticaceae, Platanaceae, Juglandeae, etc. 
SERIES VIII. ORDINES ANOMALI. Relationships uncertain, near 
Series VII, hut not closely related to any other. 
Orders: Salitineae, Empetraceae, Ceratophylleae, etc. 



GYMNOSPERMAE 
Orders: Gnetaceae, Coniferae, Cycadaceae. 

B. MONOCOTYLEDONES 

SERIES I. MICROSPERMAE Ovary inferior, tricarpellary. Seeds 
very small and numerous, exalbummous. Inner perianth (and 
also outer sometimes) pctaloid. 

Orders: Orchideae, Burmanniaceae, etc. 
SERIES II. EPIGYNAE. Ovary usually inferior. Albumen copious. 

Orders: BroTneliaceae, Irideae, Amaryllideae, Haeniodoraceae, etc. 
SERIES III. Coronarieae. Ovary superior. Albumen copious. 

Orders: Liliaceae, Pontederiaceae, etc,. 

SERIES IV. CALYCINEAE. Perianth inconspicuous, sepaloid, stiff 
or herbaceous. Ovary superior. Albumen copious. 

Orders: Juncaceae, Palmae. 

SERIES V. NUDIFLORAK. Perianth lacking or reduced to scales or 
bristles. Ovary superior. 

Orders: Pandaneae, Typhaceae, Aroidcae, Lemnaceae, etc. 
SERIES VI. APOCARPAE. Perianth in one or two series or wanting 
Ovary superior. Carpels single or separate. x 

Orders: Alismaceae, Naiadaceae, etc. 

SERIES VII. GLUMACEAE. Flowers in spikelets or heads, subtended 
by imbricated bracts. Perianth scale-like or chaffy. Ovary one- 
celled, one-ovuled. 

Orders: Gramineae, Cyperaceae, etc. 



Eichler's System. The system proposed by A. W. Eichler, in 
1883, is worthy of passing note because of the fact that it con- 
stitutes the basis of the Englerian system which has come to be 
the most widely used of all modern systems of classification. A 
condensed summary of Eichler's arrangement follows: 



FROM LINNAEUS TO ENGLER AND BESSEY 



A. CYPTOGAMAE 

B. PHANEROGAMAE 



339 



I. Gymnospermae 


Series 11. Aesculinae 


II. Angiospermae 


Series 12. Frangulinae 


1. KLABSE: Monocotyleae 


Series 13. Tncoccae 


Series 1. Liliiflorae 


Series 14. Umbelhflorae 


Series 2. Enantioblastae 


Series 15. Saxifraginae 


Series 3. Spadiciflorae 


Series 16. Opuntiinae 


Series 4. Glumiflorae 


Series 17. Passiflonnae 


Series 5. Scitamineae 


Series 18. Myrtiflorae 


Series 6. Gynandrae 


Series 19. Thymelaeinae 


Series 7. Helobiae 


Series 20. Rosijlorae 


2. KLASSE: Dicotyleae 


Series 21. Leguminosae 


Subclass : Choripetalae 


Anhang: Hysterophyta 


Series 1. Ameutaceae 


Subclass : Sympetalae 


Series 2. Urticineae 


Scries 1 . Bicornes 


Series 3. Polygoninae 


Series 2. Primulinae 


Series 4. Centrospermae 


Series 3. Diospyrinae 


Series 5. Poly car picae^ 


Series 4. Conlortae 


Series 6. Rhoeadinae 


Series 5. Tubi florae 


Series 7. Cisti florae 


Series 6. Labiatiflorae 


Series 8. Columniferae 


Series 7. Campanulinae 


Series 9. Gruinales 


Series 8. Rubiinae 


Series 10. Terebinthinae 


Series 9. Aggregatae 



Orders and Families. The "series" (Reihe) in this system 
is essentially our modern order. Each series was divided into a 
number of "orders" that are approximately the equivalents 
of our later families. The inclusion of the Hysterophyta as an 
"anhang" of the Choripetalae is an indication that these inter- 
esting parasitic flowering plants were not clearly understood at 
that time and that their relationships were very puzzling. The 
group includes the mistletoes, Loranthaceae, the rafflesias, 
Rafflesiaceae, and the balanophoras, Balanophoraceae. Eichler 
also included the Indian pipes, Aristolochiaceae, in this group 
although they are not parasitic. 

It should be noted that Eichler's system finally separates the 
Gymnosperms from their usual position between the Dicotyledons 
and Monocotyledons and raises the group to coordinate rank 
with the Angiosperms, and lower than the latter. The prestige 
of Bentham and Hooker's system had resulted in the retention 
of the anomalous position of the Gymnosperms far longer than 
the facts of morphology and development warranted. 



340 



FLOWERS AND FLOWERING PLANTS 



A NOTABLE SYSTEM BY ENGLER 

The system proposed by Adolph Engler is based largely upon 
Eichler's system, but he also adopted certain features of the 
systems of classification proposed by A. Braun (1864) and A. 
Brongniart (1843). Engler, a German botanist, was born in 
1844, and for about thirty years was professor of botany in the 
University of Berlin, and director of the great botanical garden 
and museum in that city. His system of classification was first 
published as a guide to the botanical garden of Breslau in 1892. 

The system soon began to 
appear in a more elaborated 
form in Kngler's "Die Natiir- 
lichen Pflanzenfamilien/ 1 the 
publication of which has con- 
tinued with numerous vol- 
umes, various supplements, 
syllabi, and revisions from 
1895 to the present. The 
work is now represented by 
more than twenty volumes of 
copiously illustrated text, con- 
tributed by numerous authors, 
but from the beginning it has 
been under the master edi- 
torial hand of the originator. 
A second edition is now being 
prepared, of which several 
numbers have already 
appeared. This system has 
been the dominant scheme of plant classification in most of 
the world for many years since 1900. Practically all of the 
flowering plant manuals of all countries are now arranged accord- 
ing to the Englerian system. 

Outline of Engler's System. Numerous and more or less 
significant changes in details have been made by the author 
during the years since the system was first proposed. Neverthe- 
less, the latest arrangement and sequence of groups in the 
Engler system are much the same as in the original. The fol- 
lowing synopsis of the system is taken from the ninth and tenth 
German edition of the " Syllabus der Pflanzenfamilien" by 
Engler and Gilg, published by Gebriider Borntraeger, Berlin, in 




ADOLF ENGLER (1M1-1 ( UO). (Photo fur- 
nished by Brooklyn Botanic Garden.) 




FROM LINNAEUS TO ENGLER AND BESSEY 341 

1924. The synopsis is given for the flowering plants alone 
since we are concerned primarily with these. 

CLASS 1. MONOCOTYLEDONEAE 

1. ORDER: P AND AN ALES. 

Families: Typhaceae, Sparganiaceae, etc. 

2. ORDER: HELOBIAE. 

1. Suborder: Potamogetonineae. 

Families': Potamogetonaceae, Naiadaceae. 

2. Suborder: Alismatineae. 

Family : A lismataceae. 

3. Suborder: Butomineae. 

Families: Butomaceae, Hydrocharitaceae. 

3. ORDER: TRIXIRIDALES. 

Family: Triuridaceae. 

4. ORDER: GLUMIFLORAE. 

Families: Gramineae, 

5. ORDER: PRINCIPES. Fa 

6. ORDER: SYNANTHAE. F&ini^Kyclanthaceae. 

7. ORDKR: SPATHIFLORAE. 

P^amilies: Araceae, Lemnaceae. 

8. ORDER: FARINOSAE. 

1. S\iborder: Flagellariineae 

Family: Flagellariaceae. 

2. Suborder: Enantioblastae 

Families: Restionaceae, Mayacaccae, Xyridaceae, Enocaulaceae. 

3. Suborder: Bromelimeae. 

Families: Thurniaceae, Bromehaceae. 

4. Suborder: Commelinineae. 

Family: Commelinaceae. 

5. Suborder: Pontederiineae. 

Family: Pontederiaceae. 

6. Suborder: Philydrmeae. 

Family : Philydraceae. 

9. ORDER: LILIIFLORAE. 

1. Suborder: Juncineae. Family: Juncaceae. 

2. Suborder: Liliineae. 

Families : Liliaceae, Haemodoraceae, A maryllidaceae. 

3. Suborder: Iridineae. Family: Iridaceae. 

10. ORDER: SCITAMINEAE. 

Families: Musaceae, Zingiberaceae, Cannaceae, Marantaceae. 

11. ORDER: MICROSPERMAE. 

1. Suborder: Burmanniineae. 

Family : Burmanniaceae. 

2. Suborder: Gynandrac. Family: Orchidaceae. 

CLASS 2. DICOTYLEDONEAE 

1. Subclass ARCHICHLAMYDEAE (Choripetalae and Apetalae). 
1. ORDER: VERTICILLATAE. Family: Casuarinaceae. 




342 FLOWERS AND FLOWERING PLANTS 

2. ORDER: PIPERALES. 

Families: Saururaceae, Piperaceae, etc. 

3. ORDER: SALIC ALES. Family: Salicaceae. 

4. ORDER: GARRYALES. Family: Garry aceae. 

5. ORDER: MYRICALES. Family: Myricaceae. 

6. ORDER: BALANOPSIDALES. Family: Balanopsidaceae. 

7. ORDER: LEITNERIALES. Family: Leitneri aceae. 

8. ORDER: JUGL AND ALES. Family: Juglandaceae. 

9. ORDER: BATIDALES. Family: Batidaceae. 

10. ORDER: JULIANALES. Family: Julianaceae. 

11. ORDER: FAGALES. Families: Betulaceae, Fagaceae. 

12. ORDER: URTICALES. 

Families: Ulmaceae, Moraceae, Urticaceae. 

13. ORDKR: PROTEALES. Family: Proteaceae. 

14. ORDER: SANTALALES. 

1. Suborder: Saritalineae,, 

Families: SantalaceJjj[ Olacacvae, etc. 

2. Suborder: Loran thine 

Family: Lorafrithace( 

3. Suborder: Balanophoril 

Family: Balanophoraceae. 

15. ORDER: ARISTOLOCHIALES. 

Families: Aristolochiaceae, Rafilesiaceae, II ydnor aceae. 

16. ORDER: POLYGONALES. Family: Polygonaceae 

17. ORDER: Centrospermae. 

1. Suborder: Chenopodiineae. 

Families: Chenopodiaceae, Amarantnceae. 

2. Suborder: Phytolacciiieae. 

Families: N yctaginaceae, Phytolaccaceae. 

3. Suborder: Portulacineae. 

Families: Portidacaceae, Basellaceae. 

4. Suborder: Caryophyllineae. 

Family : Caryophyllaceae. 

18. ORDER: RANALES. 

1. Suborder: Nymphaeineae. 

Families : Nymphaeaceae, Ceratophyllaceae. 
2. f Suborder: Trochodendrineae. 

Families : Trochodendraceae, Cercidiphyllaceae. 

3. Suborder: Rammculineae. 

Families: Ranunculaceae, Berberidaceae, Memspermaceae, 
etc. 

4. Suborder: Magnoliineae. 

Families: Magnoliaceae, Anonaceae, Myristicaceae, Laura- 
ceae, etc. 

19. ORDER: RHOEADALES. 

1. Suborder: Rhoeadineae. Family: Papaveraceae. 

2. Suborder: Capparidineae. 

Families: Capparidaceae, Cruciferae, etc. 

3. Suborder: Resedineae. Family: Resedaceae 



FROM LINNAEUS TO ENGLER AND BESSEY 343 

4. Suborder: Moringineae. Family: Moringaceae. 

5. Suborder: Bretschneiderineae. Family: Bretschneideraceae. 

20. ORDER: SARRACBNIAL.FS. 

Families: Sarraceniaceae, Droseraceae, Nepenthaceae. 

21. ORDER: ROSALES. 

1. Suborder: Podostemonineae. Family: Podostemonaceae, etc. 

2. Suborder: Saxifragineae. 

Families: Crassulaceae, Saxifragaceae, Pittosporaceae, 
Hamamelidaceae, etc. 

3. Suborder: Rosineae. 

Families: Platanaceae, Rosaceae, Leguminosae. 

22. ORDER: PANDAL.ES. Family: Pandaceae. 

23. ORDER: GERANIAL.ES. 

1. Suborder: Geraniineae. 

Families: Geraniaceae, Oxalidaceae, Tropaeolaceae, Lina- 
ceae, etc. 

2. Suborder: Malpighitf 

Families: Malmamceae, Trigoniaceae, etc. 

3. Suborder: PolygajfijKe. Families: Polygalaceae, etc. 

4. Suborder: Dichapl^Bneae. Family: Dichnpetalaceae. 

5. Suborder: Tricocca^T 

Family: Euphorbiaceae. * 

6. Suborder: Callitrichineae. Family: Callitnchaceae. 

24. ORDER: SAPINDAL.ES. 

1. Suborder: Buxineac. Family: Buxaceae. 

2. Suborder: Empetrineae. Family: Empetraceac. 

3. Suborder: Coriariineae. Family: Comariaceae 

4. Suborder: Linmanthineae. Family: Limnanthaceae. 

5. Suborder: Anacardiineae. Family: Anacardiaceae. 

6. Suborder: Celastrineae. 

Families: Cyrillaceae, Aquifoliaceae, Celastraceae, Staph- 
yleaceae, etc. 

7. Suborder: Icacinineae. Family: Icacinaceae. 

8. Suborder: Sapindineae. 

Families: Aceraceae, Hippocastanaceae, Sapindaceae. 

9. Suborder: Sabiineae, Family: Sabiaceae, 

10. Suborder: Melianthineae. Family: MeManthaeeae. 

11. Suborder: Didiereineae. Family: Didiereaceae. 

12. Suborder: Balsaminineae. Family: Balsaminaceae. 

25. ORDER: RHAMNALES. 

Families: Rhamnaceae, Vitaceae. 

26. ORDER: MALVALES. 

1. Suborder: Elaeocarpineae. Family: Elaeocarpaceae. 

2. Suborder: Chalaenineae. Family: Chalaenaceae. 

3. Suborder: Malvineae. 

Families: Tiliaceae, Malvaceae, Bombacaceae, Sterculiaceae. 

4. Suborder: Scytopetalineae. Family: Scytopetalaceae* 

27. ORDER: PARIETALES. 

1. Suborder: Theineae. 

Families: Ditteniaceae, Ochnaceae, Guttiferae, etc. 



344 FLOWERS AND FLOWERING PLANTS 

2. Suborder: Tamaricirieae. 

Families: Elatinaceae, Tamaricaceae, etc. 

3. Suborder: Cistineae. Families: Cistaceae, Bixaceae 

4. Suborder: Cochlospermineae. Family: Cochlospermaceae. 

5. Suborder: Lacistemineae. Family: Lacixtemaceae. 

6. Suborder: Flacourtiineae. 

Families: Violaceae, Tumeraceae, Pasxifloraceae, etc. 

7. Suborder: Papayineae. Family: Caricaceae. 

8. Suborder: Loasineae. Family: Loasaceae. 

9. Suborder: Datiscineac. Family: Datiscaceac. 

10. Suborder: Begoniincae. Family: Begoniaceae. 

11. Suborder: Ancistrocladineae. Family: Ancistrocladaceae. 

28. ORDER: OPUNTIALES. Family: Cactaceae. 

29. ORDER: MYRTIFLORAE. 

1. Suborder: Thymclacineac. 

Families: Thymelaeaaeae, Elaeagnaceae, etc. 

2. Suborder: Myrtineaeffik 

Families: LythraceaSJPunicaceae, Myrtaceae, Oenotheraceae, 

3. Suborder: Hippundine^^P Family : Hippuridaceae. 

4. Suborder: CyiiomorineaF Family: Cynomoraceae. 

30. ORDER: UMBELLIFLORAE. 

Families: Araliaceae, Umbelliferae, Cornaceae. 

2. Subclass: METACHLAMYDEAE, or Sympetalae. 

1. ORDER: DIAPENSIALES. 

Family : Diapensiaceae. 

2. ORDER: ERICALES. 

1. Suborder: Ericineae. 

Families: Clethraceae, Pirolaceae, Ericaceae. 

2. Suborder: Epicridineae. Family: Epicridaceae. 

3. ORDER: PRIMULALES. Family: Primulaceae, etc. 

4. ORDER: PLUMBAGINALES. Family: Plumbaginaceae. 

5. ORDER: EBENALES. 

1. Suborder: Sapotineac. Family: Sapotaceae. 

2. Suborder: Diospyrineae. 

Families: Ebenaceae, Symplocaceae, tityracaceae. 

6. ORDER: CONTORTAE. 

1. Suborder: Olcincae. Family: Oleaceae 

2. Suborder: Gentianineae. 

Families: Loganiaceae, Gentianaceae, Apocynaceae, 
A sclepiadaceae. 

7. ORDER: TUBIFLORAE. 

1. Suborder: Convolvulineae. 

Families: Convolvulaceae, Polemoniaceae. 

2. Suborder: Lennoineae. 

3. Suborder: Boraginincae. 

Families: Boragiriaceae, Hydrophyllaceae. 

4. Suborder: Verbenineae. Families: Verbenaceae, Labiatae. 

5. Suborder: Solanineae. 



FROM LINNAEUS TO ENGLER AND BESSEY 345 

Families: Solanaceae, Scrophulariaceae, Bignoniaceae, 
Orobanchaceae, etc. 

6. Suborder: Acanthineae. Family: Acanthaceae. 

7. Suborder: Myoparineae. Family: Myoporaceae. 

8. Suborder: Phrymineae. Family: Phrymaceae. 

8. ORDER: PLANTAGINALES. Family: Plantaginaceae 

9. ORDER: RUB TALES. 

Families: Rubiaceae, Caprifoliaceae, Adoxaceae, Valeri- 
anaceae, Dipsacaceae. 

10. ORDER: CUCURBITALES. Family: Cucurbitaceae. 

11. ORDER: CAMPANULATAE. 

Families: Campanulaceae, Brunoniaceae, Calyceraceae, 
Compositae. 

Numerous Subdivisions. As one examines the system of 
Engler for the flowering plants ij is impressed by the unnecessary 
multiplication of "unterreihe" or suborders. There are many of 
these groups with a single fahrily. In such instances it would 
seem quite adequate if the families were included directly under 
the respective orders instead of interpolating another subdivi- 
sion between the order and family. When we examine the 
system more closely we also note that this tendency to introduce 
subdivisions that are frequently unnecessary and more or less 
confusing is extended so far as to interpolate subfamilies between 
many families and groups of genera. 

Position of Apetalae and Amentiferae. The apetalous and 
amentiferous families are still placed at the beginning of the 
system, as to indicate that these are still regarded as the most 
primitive flowering plants. Investigations during the past two 
decades would dictate that this old notion should be abandoned 
and that the magnolias and the buttercups and their kin are to 
be regarded as the most primitive groups from which the other 
flowering plants have developed. There is a growing volume 
of information that leads to a conviction that apetalous and 
amentiferous (wind-pollinated) plants, indeed, are the very 
highest rather than the lowest types of flowering plants. These 
notions are certainly more nearly in accord with modern opinions 
of the evolution of Angiosperms and the relationships should 
therefore be reflected in our attempts to classify flowering plants 
according to a natural or phyletic system. 

Influence of European Systems. Systematic botany has been 
dominated from the beginning by European botanists. The 
modern period in the history of botany may be considered as 



346 FLOWERS AND FLOWERING PLANTS 

beginning with Linnaeus (1707-1778). Since the time of Lin- 
naeus many systems of classification have been proposed by 
Europeans which have left a lasting impress upon the subject. 
A few of the more important of these have been briefly considered 
in the preceding sections of this book as an introduction to the 
history of the development of the natural system. 

Classification in America. For the most part American 
botanists have been content to accept the schemes of classifica- 
tion proposed by their old world contemporaries with little or 
no modification. Asa Gray (1810-1888), the nestor of systematic 
botany in this country, utilized the essential features of the de 
Candollean and later the Bentham and Hooker systems in his 
extensive publications on the flora of North America. The 
latter system of classification apgears with little modification in 
the sixth edition of Gray's " Manual" published in 1889 and 1890. 
Gray's work at Harvard doubtless did more than that of any 
other American botanist to acquaint the world with the flora 
of our country in the nineteenth century. Gray was more 
interested in the discovery and determination of the plants 
of America than in the development of systems of classification. 
He did not work out a scheme of classification of his own. 

<* 
THE SYSTEM PROPOSED BY BESSEY 

The system of classification proposed by Bessey (1845-1915) 
is probably the most important contribution of this sort by an 
American botanist. The Besseyan system has attracted some 
attention in other parts of the world, but it has never been 
accepted and adopted to any great degree in any country. 
Bessey was one of Gray's students. Early (1884) in his 
botanical career he became professor of botany in the University 
of Nebraska where he did the most of his work. The latest 
synopsis of his proposed system of classification was published 
after his death in 1915. 

Earlier Proposals by Bessey. Bessey 's system in the beginning 
was largely modeled after the de Candollean system as modified 
by Bentham and Hooker as is shown in his first publication 1 
(1894) dealing with his scheme of classification. This is essen- 
tially a revised arrangement of the Bentham and Hooker system 
with new names suggested for the orders. The system with the 

l " Evolution and Classification," Cont. Bot. Dept. Univ. Nebr., N. S. 
VII, 1894. 



FROM LINNAEUS TO ENGLER AND BESSEY 347 

Bentham and Hooker groups in parentheses is presented in 
outline form below: 

Subclass Monocotyledones 

ORDER: ALTSMALES (Apocarpae). Alismaceae, etc. 
ORDER: LILIALES (Coronaricae). Liliaceae, etc. 
ORDER: AROIDALES (Nudiflorae). Araceae, etc. 
ORDER: PALMALES (Calycinae). Palmaceae, etc. 
ORDER: GLUMALES (Glumaceac). Gramineae, etc. 
ORDER: HYDBALES (Hyd rales). 
ORDER: IRIDALES (Epigynae). Iridaceae, etc. 
ORDER: ORCHID ALES (Microspermae). Orchidaceae. 

Subclass Dicotyledones 

POLYPETALAE (Chonpctalae) 
I. THALAMIPLORAE. 

ORDER: RAN ALES. Ranunculaceae, Magnohaceae, etc. 
ORDER: PARIETALES. Cruciferae, Violaceae, etc 
ORDER: POLYGALALES. Polygalaceae, etc. 
OR^ER- CARYOPHYLLALES. Caryophyllaceae, etc. 
ORDER: GUTTIFERALES. Hypericaceae, etc. 
ORDER: MALVALES. Malvaceae, etc. 

II. DISCIFLORAE. 

ORDER: GERANIALES. Geraniaceac, etc. 
ORDER: CELASTRALE&. Celastraceae, etc. 
ORDER: SAPINDALES. Sapindacede, etc. 
III. CALYCIFLOUAE. 

ORDER: ROSALES. Rosaceae, Leguminosae, etc. 
ORDER: MYRTALES. Myrtaceae, Onagraceae, etc. 
ORDER: PASSIFLORALES. Loasaceae, etc. 
ORDER: CACTALES. Cactaceae, etc. 
ORDER: UMBELLALES. Umbelliferae, etc. 

GAMOPETALAE 
I. HETEROMERAE. 

ORDER: PRIMULALES. Primulaceae, etc. 
ORDER: ERICALES. Ericaceae, etc. 
ORDER: EBENALES. Ebenaceae, etc. 

II. BlCARPELLATAE. 

ORDER: GENTIANALES. Gentianaceae, etc. 
ORDER: POLEMONIALES. Polemoniaceae, etc. 
ORDER: PERSONALES. Scrophulariaceae, etc. 
ORDER: LAMIALES. Labiatae, etc. 

III. INFERAE. 

ORDER: RUBIALES. Rubiaceae, etc. 
ORDER: CAMPANALES. Campanulaceae, etc. 
ORDER: ASTERALES. Compositae, etc. 



348 FLOWERS AND FLOWERING PLANTS 

The most evident differences noted in this plan of Bessey's as 
compared with Bentham and Hooker's, besides changes in the 
names of a number of the groups, are the rearrangement of the 
Monocotyledons, the distribution of the Monochlamydeae among 
the other orders, the dropping out of the gymnosperms, and the 
exchange of position of the Heteromerae and the Inferae, Bessey 
placing the latter above the former. 

Later Plans by Bessey. A later plan published by Bessey in 
1897 differs from the above system, mainly in relating the Disci- 
florae to the Calyciflorae rather than to the Heteromerae, and in 
the inclusions of some of the orders. He also returned to the use 
of Bentham and Hooker's names for the orders of Monocoty- 
ledons. The paper also contains valuable statistical data and 
the beginnings of Bessey's " dicta" which appear in definite form 
in his last published synopsis in 1915. His outline of flowering- 
plant classification was somewhat modified in 1907 and again in 
1909, along with the publication of an outline for the whole 
vegetable kingdom. 

The outline of classification suggested by H. Hallier during 
this period had many features in common with the systems 
proposed by Bentham and Hooker and by Bessey. 

The Besseyan System in Final Form** Bessey's last arrange- 
ment was published in 19 15 1 with a discussion of the principles 
of classification (dicta) which were followed in the development 
of the system. This scheme subdivides the flowering plants 
(Anthophytd) into 32 orders and 300 families. 

An outline of the system of classification of flowering plants 
proposed by Bessey (1915), with the orders and a few representa- 
tive families, concludes our brief study of the evolution of the 
natural system of classification for flowering plants. 

Class : Alternifoliae (Monocotyledoneae) 

SUBCLASS: STROBILOIDEAE. 

ORDER: ALISMATALEB: Alismataceae, Typhaceae, Pandanaceae, Spar- 

ganiaceae, etc. 
ORDER: LILIALES: Liliaceae, Commelinaceae, Juncaceae, Naiadaceae, 

Xyridaceae. 

ORDER: ARALES: Araceae, Lemnaceae. 
ORDER: PALMALES: Palmaceae. 
ORDER: GRAMINALES: Cyperaceae, Poaceae. 

1 "The PhyloRcnetic Taxonomy of Flowering Plants." Ann. Missouri 
Ilotan. Garden, 2: 108-164, 1915. 



FROM LINNAEUS TO ENGLER AND BE88EY 349 

SUBCLASS: COTYLOIDEAE. 

ORDER: HYDRALES: Valhsnenaceae. 

ORDER: IRIDALES: Amaryllidaceae, Iridaceae, Musaceae, Cannaceae, 

Zingiberaceae, jyioscoreaceae. 
ORDER: ORCHIDALES: Orchidaceae, Burmanniaceae. 

Class : Oppositifoliae (Dicotyledoneae) 

SUBCLASS: STROBILOIDEAE. "Cone flowers." 
SUPERORDER: APOPETALAE-POLYCARPELLATAE. 

ORDER: RANALES: Magnoliaceae, Anonaceae, Myristicaceae, Saururaceae, 

Piper aceae, Ranunculaceae, etc. 

ORDER: MALVALES: Malvaceae, Tiliaceae, Ulmaceae,Moraceae, Urticaceae. 
ORDER: SARRACENIALES: Sarraceniaceae, Nepenlhaceae. 
ORDER: GERANIALES: Geraniaceae, Oxalidaceae, Linaceae, Balsannna- 

ceae, Rutaceae, Euphorbiaceae. 

ORDER: GUTTIFERALES: Theaceae, Gvttiferaceae, etc. 
ORDER: RHOEADALES: Papaveraceae, Nymphaeaceae, Cappamdaceae, 

Brassicaceae (Crudferae) . 
ORDER: CARYOPHYLLALES: Caryophyllaceae, Portulacaceae, Salicaceae, 

Phytolaccaceae, Amaranthaceae, etc. 
SUPERORDER: SYMPETALAE-POLYCARPELLATAE . 

ORDER: EBENALES: Ebenaceae, Sapotnceae, Styracaceae. 
ORDER: ERIC ALES: Ericaceae, Pyrolaceae, Clethraceae. 
ORDER: PRIMULALEH: Primulaceae, Plantaginaceae. 
SUPERORDER. SYMPETALAE-DICARPELLATAE. 

ORDER: GENTIAN ALES iGentianaceae, Oleaceae, Apocynaceae, Asdepiada- 

ceae. 

ORDER: POLEMONIALES: Polemoniaceae, Convolvulaceae, etc. 
ORDER: SCROPHULARIALES: Scrophulariaceae, Acanthaceae, Martyma- 

ceae, Bignoniaceae. 

ORDER: LAMIALES: Phrymaceae, Lamiaceae, etc. 
SUBCLASS: COTYLOIDEAE. ''Cup flowers." 
SUPERORDER: APOPETALAE. 

ORDER: ROSALES: Rosaceae, Malaceae, Mimoaaceae, Cassiaceae, Fabo- 

ceae, Saxifragaceae, etc. 
ORDER: MYRTALES: Lythraceae, Punicaceae, Myrtaceae, Oenotheraceae, 

A ristolochiaceae, Rafflexiaceae. 

ORDER: LOASALES: Loasaceae, Cucurbitaceae, Begoniaceae. 
ORDER: CACTALES: Cactaceae. 
ORDER: CELASTRALES: Rhamnaceae, Vitaceae, Celastraceae, Aqui- 

foliaceae, Staphyleaceae, Elaeagnaceae, Loranthaceae. 
ORDER: SAPINDALEB: Sapindaceae, Aceraceae, Anacardiaceae, Juglanda- 

ceae, Betulaceae, etc. 

ORDER: UMBELLALES: Araliaceae, Apiaceae (Umbelliferae), Cornaceae. 
SUPERORDER: SYMPETALAE. 

ORDER: RUBIALES: Rubiaceae, Caprifoliaceae, Valerianaeeae, Dipsa- 

caceae. 

ORDER: CAMPANULALES: Campanulaceae. 
ORDER: ASTERALES: 14 families, including Ambrosiaceae, that are 

usually treated as "tribes" by other authors. 



350 FLOWERS AND FLOWERING PLANTS 

The Arrangement in General. These orders and families are 
distributed in three main groups diverging from the Ranales. 
One group is the Monocotyledons beginning with the hypogynous 
arrowheads, Alismatales, and then leading successively to lilies, 
Liliales, and epigynous irises, Iridales, and ending in the orchids, 
Orchidales. The Hydrates, Arales, Palmales, and Graminales are 
all derived from the Liliales. These latter orders are regarded 
as lateral branches of the Liliales which lie in the main series Of 
Monocotyledons. 

The Dicotyledons are represented as in two separate series, 
each originating in the Ranales. One of these gives rise to the 
roses, Resales, bitters^eets, Celaslrales, umbellifers, Umbellales, 
madders, Rubiales, and ends in the composites, Asterales. The 
myrtles, Myrtales, are regarded as a side line from Rosales, with 
the loasas, Loasales, and cactuses, Cactales, as branches of this 
order. The soapberries, Sapindales, are a branch of Celastrales, 
and bluebells, Campanulales, represent a lateral branch from the 
lower composites, Asterales. The other line of Dicotyledons 
begins in the Ranales and leads to pinks, Caryophyllales, and a 
group of closely related orders including mallows, MalvaleSj geran- 
iums, Geraniales, teas, GuttiferaleSj and crucifers, Rhoeadales, and 
then continues to another group including primroses, 
Primulales, heathers, Ericales, and ebonies, Ebenales, and termi- 
nates in a group of four orders including phloxes, Polemoniales, 
gentians, Gentianales, mints, Lamiales, and snapdragons, Scroph- 
ulariales. The first series leads from the hypogynous butter- 
cups through the epigynous and sympetalous madders, to the 
bluebells and asters. The other series leads from the buttercups 
through the polypetalous, actinomorphic geraniums, pinks, and 
crucifers, to the sympetalous primroses and their kin, to the 
phloxes and gentians, and finally to the sympetalous and zygo- 
morphic mints and snapdragons. This line is, with few excep- 
tions, hypogynous. The order of development and the grouping 
of orders within the several superorders of the system are shown 
in the accompanying figure. 

Bessey proposed the doubtfully useful terms Alternifoliae 
and Oppositifoliae for the old terms Monocotyledoneae and Dicoty- 
ledoneae respectively, since he states that the old terms are now 
somewhat misleading. The new terms are based upon the 
position of the first leaves (cotyledons) of the embryo in the 
two groups. 



FROM LINNAEUS TO ENGLEH AND BESSEY 



351 



COTYLOIDEAE 
SYMPETALAE 



ASTERALES 



CAMPANULALES 



RUBIALES 



COTYLOIDEAE 

ORCHIDALES 
IRIDALES 
HYDRALES 



LOASALES 

STROB1LOIDEAE \ UMBELLALES 

I CACTALES \ 

ULIALES > * 

MYRTALES 



GRAMINALES 



PALM ALES 



SAPINDALES 



STROBILOIDEAE 
SYMPETAUE - DICARPELLATAE 

LAM I ALES 

I 

SCROPHULARIALES 

I 

GENTIANALES 

! 

POLEMONIALES 

I 

SYMPETALAE - POLYCARPELLATAE 

PRIMULALES 

I 

ERICALES 



EBENALES 



APOPETALAE - POLYCARPELLATAE 
I 

CARYOPHYLLALES 




Diagram to show the sub-classes, super-orders, and orders of flowering plants 
and their relationships according to the last arrangement by Bessey. 



352 

A 

GRAMINALES 



FLOWERS AND FLOWERING PLANTS 
B C 



ORCfflDALES 

ORCHIDS 
GRASSES 



BUCKWHEATS 




GOOSEFOOTS 



CARYOPHYLLALES 

PINKS 



HYDRALES 

WATER WEEDS 



MALVALES 
MALLOWS 



Outline to show the three principal series of flowering plants, A, the mono- 
cotyledons, B and C, the dicotyledons. The apetalous and anemophilous groups 
are designated by broken lines. Rearranged from Bessey according to Clements. 



FROM LINNAEUS TO ENGLER AND BESSEY 353 

The more conspicuous differences noted in this arrangement as 
compared with the earlier (1893) proposal of the author are in the 
subdivision of the Monocotyledons into two subclasses based upon 
hypogyny and epigyny, the introduction of new names for the 
subclasses of Dicotyledons, and the separation of the Gamopetalae 
of the Bentham and Hooker system to form the two groups that 
constitute the upper series and the termini of the two main lines 
of Dicotyledons in the Besseyan system. The last change also 
featured the 1897 edition of Bessey's system. 

Comparison with Engler's System. The most striking con- 
trasts between the Engler system and the Bessey system for 
flowering plants may be noted. The numerous suborders of the 
Engler system are not featured in the Besseyan system. Engler 
regards the diclinous Apetalae and Amentiferae as primitive 
forms and hence he places them at the beginning of his arrange- 
ment, but Bessey regards the monoclinous, apopetalous, spiral, 
buttercup type (Ranales) as the primitive form from which all 
other flowering plants have developed; the latter author regards 
the diclinous Apetalae and Amentiferae as " reduced" or " simpli- 
fied" forms of higher types so he distributes these among various 
other derived groups. Engler gives more weight to apopetaly 
versus sympetaly than to hypogyny versus epigyny in the estab- 
lishment of his groups and lines of relationships. Bessey likewise 
ranks sympetaly high, but he also regards epigyny as a mark 
of higher types. A more extended illustration of these and 
other " principles" upon which our modern systems of flowering- 
plant classification are founded will be presented in Chapters 
X and XL 



CHAPTER XXVII 
COLLECTING AND PREPARING SPECIMENS 

Precautions for the Collector. Ideally, flowering plants should 
be classified in the field at the time they are gathered, but that is 
often impossible, so it is necessary to collect specimens and prepare 
them for future study and reference. Accuracy and facility 
in the determination of flowering plants on the basis of speci- 
mens secured in the field are largely dependent upon the care and 
completeness with which the materials are gathered and prepared. 
Poorly treated, incomplete, and fragmentary specimens are usually 
unpleasant to work with and they may often lead to uncertainties 
and inaccuracies in identification even by the most careful 
specialists. One should not submit such materials for determi- 
nation when it is possible to secure more nearly perfect and 
satisfactory specimens. If one is making his own private col- 
lection of plants he should bear the same precautions in mind in 
order that much time may be saved, his work be more pleasant, 
his specimens be much more accurately named, and the whole 
collection be an object of beauty as well as of scientific merit. 

Equipment for Collecting. The equipment necessary for such 
work is relatively simple and inexpensive. Makeshift appa- 
ratus is often useful, especially to the beginner. However, if one 
intends to continue his collecting indefinitely or if he is planning 
an extensive collecting expedition, it will be profitable for him 
to give more thought and care to assembling the equipment 
that will return the most efficient and pleasurable service. 

Notebooks. A field notebook is an indispensable feature in the 
kit of a careful collector. The type of notebook used may rest 
upon the personal demands of the individual, but, in this day of 
almost unlimited resources of this nature he may easily err in his 
choice. Of the numerous kinds available, the best for this pur- 
pose is probably one of the pocket-size, loose-leaf forms with 
flexible leather or leatheroid cover. An important advantage 
possessed by this type of notebook is the ease with which one's 
invaluable field notes and records dealing with material collected 

354 



COLLECTING AND PREPARING SPECIMENS 355 

may be removed and filed away for safe keeping and future 
reference. A handy numerical scheme should be adopted for 
keeping the record of the individual collections. Careful records 
should also be made of dates, habitat details, abundance, asso- 
ciated species, and other features of interest and value concern- 
ing the specimens. The field notes kept in this way should later 
furnish all of the details necessary for the temporary and perma- 
nent labels for the specimens collected, as well as for an orderly 
account of the flora and general phytogeographical features of 
the areas involved. 

Containers for Specimens. A container of some sort must be 
at hand in which the specimens may be placed as they are gath- 
ered in the field. This may take the form of a collecting can 




FIG. 204. A convenient collecting can or vasculum Description in text. 

or vasculum (Fig. 204) or a light, portable press (Fig. 208) may 
be used for the same purpose. Almost any sort of a bag, pack, 
or rucksack may be used, but best results are likely to be 
secured for the largest number of specimens by the use of a 
vasculum. This is made of tin and it may be of any desirable 
size. A convenient form is oval in section, and about 20 inches 
long by 8 inches wide and 10 inches high. Larger cases are likely 
to be bunglesome and to become too heavy when filled. This 
oblong case should have a lid 5 or 6 inches high on one side 
extending to within 1 inch of each end and hinged to the body 
along the entire lower edge. The upper edge of the lid should be 
provided with a substantial clamp or sliding bolt made of heavy 
wire in order that the vasculum may be handily and securely 
closed. This large opening will enable one to place the speci- 
mens in the case with greatest ease and with the least folding and 
also will permit their removal with the least tearing or other 
injury. The vasculum should have a ring or buckle at each end 



356 FLOWERS AND FLOWERING PLANTS 

for the attachment of a carrying strap. A comfortable handle 
with wooden or leather handhold should also be firmly riveted to 
the top of the vasculum on the center line (Fig. 204). This com- 
bination of carrying strap and handle is often very welcome on 
long trips with a heavy vasculum. All of the joints should be 
very firmly soldered and the hinges very substantially con- 
structed if one is to secure uninterrupted and efficient service 
from such a collecting can for many seasons. 

A good tin shop is usually prepared to construct such containers 
at a nominal price or they may be purchased from the regular 
dealers in botanical supplies. If the local tinner makes them it 
is well to have them thoroughly japanned black or preferably 
painted with a good grade of light green or white paint. This 
will prevent rusting and will add a desirable touch of refinement 
to the job. Plants will remain fresh or only slightly wilted in 
such a container for 2 or 3 days if necessary. 

Portable Presses. A portable field press (Figs. 208 and 209) 
may receive the plants as they are gathered, and so the vasculum 
may not be needed, but as a rule such a press cannot entirely sup- 
plant the vasculum. The portable press is especially valuable 
in cases where the flowers close or the leaves wilt badly soon 
after the specimens are taken even if they are placed in the collect- 
ing can. Such experiences indicate the value of the field press 
to be used either with or without the vasculum. Likewise, if 
one is doing only a very limited amount of collecting, the portable 
press may meet all the demands of a temporary container. 

Construction of Presses. The portable press at best can hold 
relatively few specimens but even then it must be constructed of 
the lightest materials practicable. Most plant presses, portable 
or otherwise, are 10 to 12 inches wide and 15 to 18 inches long, 
and are made of two thin boards, wire netting, or slatted strips 
of thin wood laid crossways (Figs. 208 arid 209), and the two 
bound together more or Jess like the cover boards of a book by 
means of straps, cords, chains, or other sorts of clamps. The 
desired pressure is secured by tightening the straps or clamps 
by means of any of the convenient methods available. The 
two sides of a very serviceable portable press are made by 
stretching galvanized wire netting with y- or J^-inch mesh 
over two oblong frames 12 inches wide by 18 inches long (Fig. 
209). The frames may be made of thin strips of heavy wood 
rigidly mortised at the corners, or preferably of heavy %- 



COLLECTING AND PREPARING SPECIMENS 



357 



inch strap iron firmly welded at the corners. If the iron frame 
is used the wire netting may be neatly and firmly soldered about 
the frame. The pressure on such a press may be secured by the 
use of two broad leather or web straps, or by means of four 
strong flat-link chains anchored at the edges of one of the sides 
of the press and caught by corresponding hooks or clamps at 
the edges of the other side of the press. In this case the total 
thickness of the press would be determined by the length of the 
chains used. A convenient handle may be secured for the press 
by the use of an ordinary shawlstrap or a permanent handle 
may be attached to the frames or chains of the press. The press 
is completed by the addition of a few sheets of drying paper, 
filing sheets, and ventilators, all of which will be described in 
the following pages. 




Fia. 205. Useful collecting tools, diggers, etc. A, trowel with narrow blade: 
B, combination pick and adz with detachable handle; (7, trowel with broad 
blade. See descriptions in text. 

Useful Diggers. Some sort of a trowel or plant digger (Fig. 
205) is usually necessary for obtaining roots, tubers, bulbs, and 
other subterranean parts. Here again the possible choices are 
numerous and the mistakes are frequent on the part of the 
amateur. The ordinary light trowels used by the florist and 
gardener are usually constructed of too light materials and these 
are put together poorly to serve the varied needs of the plant 
collector. TJie florist and the gardener usually work with light, 
crumbly, and shallow soils, whereas the collector is required to 
dig his plants from a great variety of soils that may be extremely 
hard and firm or even rocky and it may be necessary to go to 
considerable depth in such soils. The collector's digger must, 
therefore, be used more roughly and it must be more rigidly 



358 FLOWERS AND FLOWERING PLANTS 

constructed (Fig. 205, A, C). The best kind of trowel for 
the varied needs of the plant collector is one with a narrow, 
slightly hollow blade, say about 2 inches wide, made of heavy 
steel, in which the steel is continuoiis'Tbackward into the shank or 
"tang" (Fig. 205, A). The hancjjj&vmay be made of hardwood 
driven into and riveted in the steel shank, or better yet, the 
handle should be formed by the backward prolongation of the 
steel of the blade and shank thus making a one piece instrument. 
The trowel with a broad, thin blade and a narrow, rod-like shank 
and cheap handle is practically worthless for these purposes. 
The best plant digger that we have used is a small but firmly 
constructed pick with a broad cutting edge and take-down 
feature (Fig. 205, B) . The heavy handle 12 inches long is made of 
hickory and both ends are supplied with a steel binding ring. 
The handle is attached to the pick by means of a bolt that extends 
through the head of the pick and the handle and is fastened by 
means of a wingnut at the upper end. This makes a very firm 
connection and at the same time provides the very convenient 
take-down feature. The detachable head may be made in the 
form of a hammer on one side and a narrow, adz-like cutting and 
digging extension on the opposite side, or the head may be com- 
posed of the latter form on one side and a narrow pick on the 
other (Fig. 205, B). This tool is readily made by a good black- 
smith. Nothing just like it is listed by any dealer. This very 
useful digger or the special trowel mentioned above may bo 
carried in a leather sheath slung from the belt or may be' conven- 
iently stowed away in a shoulder pack or bag. 

Selection of Specimens. The intelligent collector selects the 
specimens that he will take with considerable care. Promiscuous 
and careless snatching of material is wholly unscientific and is 
likely to lead to many disappointments. One should take several 
specimens of each plant unless it is very rare and likely to be 
exterminated. The plant collector should be a real conserva- 
tionist, and as such he is able to minimize his feeling of personal 
loss when he passes by a fine specimen of a rare orchid, lily, 
columbine, or some other form that is threatened with oblitera- 
tion on account of man's thoughtlessness and ignorance. But 
as a rule it is wise to take more than one specimen, unless the one 
selected is especially representative and complete. Oftentimes 
one finds that it is impossible to identify a plant accurately on 
the basis of a single specimen, and it is also often desirable to 



COLLECTING AND PREPARING SPECIMENS 



359 



secure several specimens in order to illustrate certain variations 
of the plant in question. 

Neat and Complete .Specimens. Each specimen should be 
as complete as possible; i.e., if possible it should show enough of 
the roots, rhizomes, tubers, , bulbs, corms, or other underground 
parts, stems, buds, leaves of all forms, flowers, fruits, and seeds 
to insure unquestionable identification. Naturally it is seldom 
possible to gather all of these parts for any species at a single 
visit, so it may be necessary to go to where the plants grow two 
or more times in order to secure the material to make complete 

specimens. Many plants have dif- 
ferent forms of leaves at the base 
and on the stem, and certain species 
produce unisexual flowers, and there 
are other differences in the individ- 
ual or among the individuals of 
many species that the collector 
must take in order to have the 
whole story of the plant. 

All specimens should be neatly 
made. A sharp knife is needed to 





FIG. 206. A very handy and effi- 
cient typo of dissecting microscope 
for use in the study of flowers (after 
Bausch and Lomb Optical Co.). 



FIG. 207. Useful and practical pocket 
magnifiers. These may be secured in 
various sizes and with different mag- 
nifying value (after Bauxch and Lomb 
Optical Co.} 



remove specimens of woody twigs and to divide the stems of 
herbaceous plants in order to prepare attractive material. Few 
plant parts can be broken roughly without leaving more or less 
lacerated and untidy ends or edges that reduce the attractiveness 
of the finished and mounted specimens> to say nothing of the 
appearance of the rest of the plant left in the field. Neatness 
is, in short, a virtue that should be fastidiously cultivated 
by the collector. 

Specimens should be taken on a clear, dry day whenever possi- 
ble, since the beauty as well as much of the value of such materials 



360 FLOWERS AND FLOWERING PLANTS 

depends to a large degree upon the rapidity of drying. Ordi- 
' narily they should be removed from the vasculum or portable 
press at the end of each day when the collector returns to his 
home or base station. If they are left too long in the temporary 
container they may become discolored, moulded, or so badly 
wilted and shriveled that it is wholly impossible to make satis- 
factory preparations of them. 

Dissecting Microscopes. A good dissecting microscope 
(Fig. 206) and a pocket lens (Fig. 207) are indispensable adjuncts 
to careful field work and the final determination of the species 
collected. 

Transfer to Press. An important phase of the technique of 
preparing attractive plant specimens is involved in the transfer 
of the material from the vasculum and portable press to the final 
press where they are to be dried. First of all one should see 
that each specimen is freed from all foreign material, that any 
adherent soil is shaken or washed from the roots, tubers, etc. 
that the stems are untangled, that the leaves are untangled and 
flattened, that the flowers and fruits are made to look as natural 
as possible, and that the specimens are trimmed to fit the drying 
sheets. Then they are ready for the press. 

A Practical Plant Press. Many different kinds of plant presses 
have been made and used with success. If one is to prepare 
relatively few specimens for a season or two he may do it satis- 
factorily with very simple equipment, such as two flat boards, a 
few old newspapers, large blotters, and a big rock or other weight. 
But these items would prove very inconvenient and unsatis- 
factory if a more extensive program is in mind and if one is to 
become a collector of hundreds of specimens. In the latter 
event more nearly permanent and efficient apparatus would be 
demanded. 

A very substantial plant press is made by using two 
plywood boards about 12 inches wide by 18 inches long for 
the sides of the press (Fig. 208). These may be of three-ply 
material and planed down to about % inch in thickness. The 
corners should be rounded. Three transverse strips of oak or 
birch 1 inch wide and % inch thick are laid across each of the ply- 
wood boards and securely fastened by means of screws started on 
the plywood side. One of the cross strips is fastened about 2 
inches from each end of the boards and the third one is placed 
across the center. The ends of these cross sticks are knobbed 



COLLECTING AND PREPARING SPECIMENS 



361 



and extend about 1 inch beyond the edge of the plywood boards 
in order to catch the small rope or heavy cord used to hold the 
press together and apply the pressure. A piece of window cord 
or clothesline serves very nicely for the latter purpose and it 
should be securely fastened to one of the ends of a crossbar at 
one end of the press (Fig. 208). When the specimens have been 
arranged in the press and the press is ready to be closed the cord 
is laced over the knobbed ends of the crossbars on one side 
of the press and then crossed over to the other side where the 




FIG 208. A very useful and practical type of press for the field. 

same procedure is followed until the desired pressure is obtained, 
then the cord is tied securely and the press is ready to be placed 
in the sun. 

With sufficient cord and driers one may fill such a press 
until it is 2 or 3 feet high when lying flat. One may secure 
the proper pressure in the press by bearing down upon the upper 
cover (as the press lies flat) with his foot or knee as he laces it up. 
The amount of pressure necessary to make the best specimens of 
varied material can be determined only by practice. The most 
succulent specimens may be crushed to such a degree as to be 
spoiled by a pressure that is none too great to make the best 
specimens that are relatively dry and woody. One is compelled 
to strike a compromise in such matters, but he soon learns the 
best possible practice by experience. A press of this type is strong 
enough and durable enough to last for many years even under 
heavy and rough usage. 



362 FLOWERS AND FLOWERING PLANTS 

Fillers for the Press. Too much attention cannot be devoted 
to the fillers for the press (Fig. 210), i.e., the drying sheets, 
ventilators, etc. that should be used to secure the most rapid 
and complete drying of the specimens, and that facilitate the 
handling of the latter. The fillers consist of three elements 
that we may designate as folders, drying sheets, and ventilators 
(Fig. 210). 

The folders (Fig. 210) are thin sheets of absorbent paper twice 
the size of one of the plyboards of the press and these are folded 
on the long axis to form a symmetrical folder that is about the 
area of the plyboards and drying sheets, i.e., about 12 by 18 inches. 




FILLER WITH 
''THE SPECIMENS 



HEAVY WOOD 
OR I RON FRAME 



WIRE NETTING 



SMALL CHAINS 
ANCHORED AT 
BACK OF PRESS 
AND FASTENED 
OVER HOOKS ON 
UPPER SIDE OF 
PRESS 



Fui. 209. Another satisfactory form of press for use in the field. See details 

in the text. 

Newspaper stock serves very nicely for folders, or even old news- 
papers may be used for this purpose with almost as much success. 
The purpose of the folder is to receive the specimens and to serve 
as their container as they are passing through the press. They 
also serve very well as temporary files in which the specimens 
may be kept or stored until they are to be mounted. 

The drying sheets (Fig. 210) are the most important absorbent 
element among the fillers. These may be furnished by the deal- 
ers in botanical supplies and they should be used as single sheets 
cut to the appropriate dimensions. They are of the nature of 
heavy, gray or blue felt paper and are much tougher than ordinary 
blotting paper. They may be secured in two or three different 
weights. Blotting paper cut to fit the press may be used for 
drying sheets, but this is more easily torn in handling and may 
not prove to be as valuable as the regular driers. 



COLLECTING AND PREPARING SPECIMENS 



363 



The ventilators (Fig. 210) are merely sheets of corrugated 
cardboard similar to that used in packing boxes and trimmed 
to the size of the folders and drying sheets. The most efficient 
type of corrugated board to use is that which is surfaced with 
paper on one side only. These sheets are cut double the size 
required and then folded through the middle with the facing in 
the center and the transverse corrugations on both outer surfaces. 
But this type of ventilator makes a bulky press for comparatively 
few specimens, so perhaps is to be rejected in favor of the single 
sheet of corrugated board. The facing should be made of as 
thin and as porous a paper as possible. 




UPPER 

CORRUGATED 

CARDBOARD 

VENTILATOR. 



L.UPPER FELT 

DRIER 

NF.WS-STOCK FOLDER 
TO RECEIVE SPECIMEN. 

LOWER FELT DRIER 

LOWER CORRUGATED 
CARDBOARD VENTILATOR 



Fio. 210. Fillers for a more elaborate type of press and method of manipula- 
tion. See descriptive details in the text 

Placing Specimens in the Press. The specimens are placed in 
the press (Fig. 210) by first spreading them out on the right side 
of the open folder as it lies in front of the operator. It is well to 
have a drying sheet or two under the folder or have the latter on 
a table or box in order that the specimens may be firmly pressed 
against the thin paper of the folder without tearing it. The 
plants should be placed and spaced very carefully over the sur- 
face of the folder because the form that they are given there will 
in most cases be their permanent form when removed from the 
press. Each specimen must be arranged so that it will look 
best and as natural as possible, keeping in mind that it will 
have the same appearance on the sheets upon which it will be 
mounted. The specimens ought not to be crowded or piled 
upon each other. Unruly twigs should be flattened and the 



364 FLOWERS AND FLOWERING PLANTS 

leaves neatly spread out with the minimum amount of folding 
and overlap. One should endeavor to secure the natural lie of 
all of the parts. Bulky organs must be reduced as much as 
possible by hollowing out the back, or by sectioning them in 
such a manner as not to affect the surface appearance. This 
can be done very skillfully for bulky roots, bulbs, stems, and 
even fruits, after a little practice. Some of the Compositae 
with large, radiate heads are difficult to press nicely unless one 
sections the heads or blocks up the head by disks of drying 
paper that fit closely about the involucre and that permit the 
rays to lie out more nearly flat. If something of this nature 
is not done the rays are likely to dry and shrivel so badly as to 
conceal their real nature in the mounted specimen. So, flowers 
with bell-shaped or inflated corollas, as in bluebell, Campanula, 
lady's slipper, Cypripedium, slipperwort, Calceolaria, etc. may 
be kept from being mashed out of all naturalness by placing a 
pad of cotton of appropriate size inside the corollas before the 
specimen is closed in the press. Other devices of the sort will 
occur to the thoughtful worker who wishes to preserve the 
naturalistic impressions of the material. 

The specimens in each folder should be distributed as uni- 
formly as possible over the entire area of the folder. This will 
tend to equalize the pressure throughout the press in a degree 
that would be impossible if the materials are gathered near the 
center of the folders. This is another example of the refined 
technique that the collector should develop rapidly. 

Temporary Labels. When the specimens have been arranged 
upon the folder a temporary label should be added for each 
species represented and then the folder is closed and placed 
in the press with a sheet of drying paper underneath and above 
it, and this in turn with a corrugated ventilator underneath and 
above the folder inclosed by the two drying sheets. Thus it 
will be seen that the layer of specimens has a sheet of absorbent 
folder, drying paper, and corrugated cardboard (Fig. 210) both 
above and below in every case when the press is made up in this 
manner. The ventilators are thus distributed through the press 
in such a manner that the drying out of the specimens is very 
greatly accelerated. In fact this plan of press management 
makes it unnecessary to remove the specimens from the press 
and change the driers when one is collecting in rather dry coun- 
tries. The necessity to conserve space in the press when one is 



COLLECTING AND PREPARING SPECIMENS 365 

collecting a great deal of material may require that the ventilators 
be used less freely. Under such conditions they may be inserted 
between every other folder or even at greater intervals as may be 
necessary or desirable. 

Care of the Press. The press should be placed in the open 
air and in the sun whenever that is possible, even in dry climates. 
But in humid regions it is best to change the press frequently 
if the most satisfactory results are to be secured with even this 
type of press. In very moist, cloudy weather it may be necessary 
to hang the press over a stove, or camp lamp, or in some other 
manner to supplement nature in the drying process if good 
specimens are to be secured. If the ventilators are omitted 
the press must be changed more frequently under all conditions. 
Some plants may be dried by this process in a few days, say less 
than a week, but most speciqs will require a longer time and some 
may not be removed safely from the press for two weeks or more. 

The material in the press should be examined each day in order 
to remove any specimens that are sufficiently cured, and to replace 
the moist driers with dry sheets. This may be done at the time 
new specimens are added when one is doing much collecting. 
Thus at any one time the press may contain material that is 
ready to be removed, some specimens that are not yet sufficiently 
dry to remove, and fresh material just added. The very best 
result can be secured only by constant attention to the press and 
the drying process, in order that changes in the drying sheets and 
ventilators may be made at proper intervals to insure the most 
perfect and rapid drying 

Changing the Press. The work and time involved in changing 
the press are reduced to the minimum when the press is made 
up according to the above plan. To change the press it is only 
necessary to loosen the cord, strap, clamps, or other binders 
and then remove the plyboard at the top. If the entire press is 
to be changed (which would ordinarily be unnecessary) one 
simply removes the ventilator and drying sheet over the first 
folder and then the latter is placed over a fresh, dry sheet and 
ventilator and then covered with the next drying sheet and 
ventilator as the start of the fresh pile of fillers. This is con- 
tinued until all of the folders have been removed and placed 
between fresh driers and ventilators when the new bundle is again 
inclosed in the press. In practice the open press is placed 
immediately in front of the operator, with a fresh stack of drying 



366 FLOWERS AND FLOWERING PLANTS 

sheets to the right of the press and just to the right of that a stack 
of fresh ventilators. As the folders with the undried plants 
are removed from the press they are at once assembled in the 
usual manner between the driers and ventilators in a new pile at 
the left of the press. When transfer is completed the specimens 
that were at the top of the press will be at the bottom of the 
freshly stacked series, and those that were at the bottom will be 
at the top. If the press is running very full for many days and 
if folders of fresh specimens are being ad4&d' frequently it is well 
that the fresh material be more or less segregated toward one 
ipkftaf the press and the drier material toward the opposite side 
ramer than ha^ng the fresh and the older material promiscu- 
ously mixed. This can be easily done without inconvenience 
if the added specimens are always jiaced in the press next to 
the last ones added and if the ordeitfl^maintamed each time the 
press is changed. ; * 

Convenience of the-JFolders. The great convenience in having 
the folders (Fig. 210) that carry the specimens is clearly evident 
during the changing of the press. If they were not used it 
would be necessary to pick up each individual specimen and 
transfer it to the new drying sheet, but with the folder one 
removes all of the specimens within a given folder at one opera- 
tion and wi^iout necessarily touching a single specimen. The 
collector srfrould look into the folders when changing the press, 
especially during the first two or three times that the folders 
are handled since it will be easily possible to spread out parts, 
straighffen tangled specimens, and make very much better prep- 
aration^fthan if no attention is given the individual specimens 
from the time they are placed in the press until they are removed. 

Aids in Drying the Specimens>-If the press is being run at 
maximumlmpacity and the supply of driers and ventilators is 
not sufficient to permit of as frequent and complete changes as 
necessary, then one may pile the folders with the specimens 
together for a few minutes while the^moist drying sheets and 
ventilators are being dried in the sunr The drying specimens 
are also more thoroughly aired by this plan and the folders 
themselves would be more nearly dried out than would be the 
case if the press is changed rapidly and the folders quickly made 
into the new bundle. Herein lie other advantages of the folders. 

The moist drying sheets and ventilators (Fig. 210) should 
always be spread out in the sun and wind as they are taken 



COLLECTING AND PREPARING SPECIMENS 367 

from the press, or if such a procedure is impossible on account 
of the weather they may be dried out over a radiator, stove, or 
other artificial source of heajfc indoors. The dried fillers may 
be kept in a convenient place and ready for the press-changing 
operation. When the specimens are dried they may be removed 
with the folders from the press and filed away or bundled up for 
shipment to the office or home to await the next or final process 
of preparation. . 

Preparing the Specimens for the Herbarium. The last phase 
of preparing the specimens for the herbarium is mounting. The 
plants may be filed in the herbarium in the folders in whk?h t^f$f 
passed through* the press (Fig. 210), tmt this is not satisfactory, 
the specimens are not readily examined, and they may become 
broken or lost. It is best to mount the specimens in a more 
permanent manner upon white cardboard; or firm ledger paper. 
The best mounting paper is a rather heavy and tough linen 
ledger paper, cut into sheets about 12 inches^ wide by 17 inches 
long, a common size furnished by the regular botanical supply 
houses being 11.5 by 16.5 inches. Smaller sheets % may be used 
for a small, private collection, but if one is to collect and mount 
many specimens he will soon appreciatS the numerous advan- 
tages of the larger mounting -sheets. 

Attaching Specimens to tjie Sheet$. Various methods have 
been used to attach the plant specimens to the mounting paper 
such as sewing them on with thread, fastening them by means 
of gummed strips of papier or cloth, or gumming the plant to 
the paper. The best way is to use a strong, permanent?* adhe- 
sive or gum, such as gum tragacant-h, or fishglue such as Eepage's 
liquid glue. The latter is prpbably^the best Adhesive readily 
available for this purpose. l\|any of the mild and mfice pleasant- 
to-use and popular pastes ire utterly worthless mr this use. 
Large or heavy specimens m'ay be reinforced by the addition of a 
few cross-bands of adhesive paper or linen straps. 

Application of AdhesiveThe glue may be spread upon the 
under surface of the specimen by means of a small brush dipped 
in the adhesive, but this is a very slow and tedious process if 
there are hundreds or thousands of specimens to mount. The 
specimens may be rapidly glued and mounted if one will spread a 
thin coating of the glue over a glass plate of appropriate size and 
then drop the specimens, one at a time, upon this surface, after 
which they are carefully lifted by the fingers or by means of 



368 FLOWERS AND FLOWERING PLANTS 

tweezers and then transferred to the mounting paper. This 
method places the glue on the proper portions of the specimen 
(i.e. the high or slightly projecting areas) where it comes into 
immediate and lasting contact with the surface of the mounting 
paper. The specimens must not be crowded upon the mount, 
unless some personal demand requires such untidy and inartistic 
procedure. p]xcess adhesive should always be removed. Frag- 
ments of material that may accumulate upon the glue-plate 
must be removed from time to time. The glue on the plate may 
be kept at the proper consistency by thinning with water or a 
weak solution of acetic acid or vinegar. A little practice will 
indicate the proper thickness of glue to use for each specimen. 
But evert so it may be necessary to keep very delicate flowers 
from sinking too deeply into the glue or to add more glue to the 
contact points of heavy specimens by means of a brush. 

The mounted specimens, accompanied by their temporary 
labels, may be stacked upon one another in a loose pile. The 
pressure secured in this manner will usually be sufficient to hold 
each specimen against the paper until the glue hardens. When 
the glue has thoroughly solidified the mounted specimens may 
be inspected for any needed reinforcement and prepared to receive 
their final labels. 

The Matter of Permanent Labels. Each sheet bearing speci- 
mens must have a neat label, 2 by 3 inches or slightly larger, 
affixed to it with glue. The preferred position of the label is in 
the lower right-hand corner, flush with the edges of the mounting 
sheet. The label should give the name of the plant, i.e. the 
genus and species, including the authority, the place collected, 
the date of taking the specimen, and the name of the collector, as 
the minimuifl requirements. Some collectors add notes concern- 
ing the nature of the habitat, abundance, etc. but the label should 
not be crowded. A statement as to altitude is a worth-while 
addition to the labels for specimens gathered in the mountains. 
If many of the species are determined by some specialist other 
than the collector it is helpful to add that item to the label also. 
An appropriate heading, such as "Flora of Nebraska," "Yose- 
mite Flora," " Flora of Santa Catalina Island," "Herbarium of 
John Smith," is a desirable feature of the label. An indication of 
the complete classification of the species, such as the class, order, 
family, is not necessary except in an amateur collection, or in a 
high-school herbarium where it is helpful to have these data in 



COLLECTING AND PREPARING SPECIMENS 369 

addition to those used in the professional herbarium. The name 
of the plant should in all cases be the most conspicuous 
entry on the label. Sometimes it is helpful to add a prominent 
synonym or two, but this is not often necessary if the author 
of the name is given. The labels should be printed for large 
herbaria, but for a small herbarium, or for private collections, 
the data may be written neatly upon the labels with good ink. 

Filing the Specimens. When the specimens have been 
mounted and the labels attached to the sheets, they should 
be filed away in any convenient case according to some definite 
plan of classification. The large herbarium is arranged by fami- 
lies in accordance with one of the well-known systems of classifica- 
tion. A small collection may also be grouped in this manner in 
the cupboard, but possibly a simple alphabetical arrangement of 
the families would be better until the number of specimens has 
increased to several hundred. Special genus and species 
portfolios of distinctive colors are sometimes employed in the 
great collections, but this plan is scarcely necessary until the 
number of specimens reaches several thousand. 

Subsequent Care Necessary. The specimens will require 
constant attention even after they are mounted and filed in the 
herbarium if the owner wishes to keep them in good condition. 
They must be dry when they are filed and they must be kept 
dry, otherwise destructive molds will develop to such a degree 
as to ruin some of the material. Insects will also attack the 
dried plants in the herbarium and unless held in check will cause 
a great amount of irreparable damage, especially in the flowers 
and fruits. If the specimens are dry when filed and if they are 
kept dry there will be little or no trouble from mold. Mercuric 
chloride, phenol, or other fungicides may be used against the 
molds, but the methods of application are so laborious and 
tedious that one should adopt every possible precaution to 
render their use unnecessary. Herbarium insects can usually be 
kept out or controlled by frequent fumigation with carbon 
disulphide or by keeping naphthalene flakes in the filing cabinets. 
The former material is usually effective if placed in a few of the 
upper compartments of the cabinets in shallow containers two 
or three times each year. 



CHAPTER XXVIII 

REFERENCE BOOKS, MONOGRAPHS, MANUALS, 
AND FLORAS 

The following lists and notes concerning a few selected mono- 
graphs, books, floras, and other references dealing with flowering 
plants may be helpful to students and others interested in the 
life history and classification of these plants. No attempt has 
been made to make this list complete or extensive, but it has been 
the intention to include a number of the more valuable works of 
reference that are more or less classic, as well as many technical 
and popular publications that are helpful to American students 
particularly. The publisher is noted in nearly all cases. 

An outline map (Fig. 211) shows the approximate ranges of 
certain American manuals. 

A. WORKS OF BROAD SCOPE, THAT ARE MORE OR LESS MONU- 
MENTAL, IN TREATMENT OR INFLUENCE UPON THE 
DEVELOPMENT OF KNOWLEDGE 

BAILLON, H. (Trans., M. M. HARTOG). The natural history of plants. 

8 Vols. Reeve & Co., 1871-1888. (5 Additional volumes in French.) 
BENTHAM, G. and J. D. HOOKER. Genera Plantarum. 3 Vols. 1862-1883. 
BESSEY, C. E. The phylogenetic taxonomy of flowering plants. Ann. 

Missouri Botan. Garden, 1915. 

BONNIER, G. and L. DU&ABLON . Cours de botanique. 1905. 
CLEMENTS, F. E. and F. LONG. Experimental pollination. Ari outline of the 

ecology of flowers and insects. Pub. 336 Carneg. Inst. Washington, 

D. C., 1923. 
COULTER, J. M. and C. J. CHAMBERLAIN. Morphology of spermatophytes. 

D. Appleton & Company, 1901. 
COULTER, J. M. and C. J. CHAMBERLAIN. Morphology of angiosperms. 

D. Appleton & Company, 1909. 
DARWIN, C. The contrivances by which orchids are fertilized by insects. 

2nd Ed. D. Appleton & Company, 1884. 
DARWIN, C. The effects of cross and self fertilization in the vegetable 

kingdom. D. Appleton & Company, 1885. 

DARWIN, C. Insectivorous plants. D. Appleton & Company, 1896. 
DECANDOLLE, A. Prodromus systematis naturalis regni vegetabilis. 

17 Vols. and 4 index Vols. Paris, 1824-1873. 

370 



REFERENCE BOOKS, MONOGRAPHS, MANUALS 371 

EICHLER, A. W. Blttthen-Diagramme. 2 Vols. 1875-1878. 

ENGLER, A. and H. PRANTL. Die naturhchen Pflanzenfamihen. 1st 

Ed. 20 Vols, 1897-1915, 2nd Ed. now in process of publication. 

Engelmann, 1924. 
ENGLER, A. Das Pflanzenreich. Issued in many separate parts, not yet 

completed. Engelmann, 1900. 
ENGLER, A. and 8. GILG. Syllabus der Pflanzenfamihen. 9th and 10th 

Eds. Borntraeger, 1924. 
GOEBEL, K. (Trans.) Outlines of classification and special morphology 

of plants. Clarendon Press, 1887. 
HALLIER, H. Provisional scheme of the natural (Phylogenetic) system of 

flowering plants. New Phytologist, 1905. 
HUTCHINSON, J. The families of flowering plants. Arranged according 

to a new system based upon probable phylogeny I. Dicotyledons. 

The Macmillan Company, 1926. 
KEENER, A. (trans. F. W. OLIVER). The natural history of plants. 4 Vols. 

in 2. Henry Holt & Company, 1894-1895. 
KNUTH, K (trans. J. R. A. DAVIS). Handbook of flower pollination. 

3 Vols. Clarendon Press, 1906-1909. 
LEMAOUT, E. and J. DECAISNE (trans. MKS. HOOKER). A general system 

of botany. Longmans, Green and Company, 1876. 

LINDLEY, J. An introduction to the natural system of botany, or a system- 
atic view of the organization, natural affinities, and geographical distri- 
bution of the whole vegetable kingdom, together with the uses of the 

most important species in medicine, the arts, and rural or domestic 

economy. Longmans, Green and Company, 1830. 
LINDLEY, J. The vegetable kingdom, or the structure, classification and 

uses of plants, illustrated by the natural system. Bradbury & Evans, 

1853. 
LOVELL, J. H. The flower and the bee. Plant life and pollination Charles 

Scribner's Sons, 1918. 
MULLER, H. (trans. D. W. Thompson). The fertilization of flowers. 

The Macmillan Company, 1883. 
RENDLE, A. B. The classification of flowering plants. Vol. 1, 1904, Vol. 

2, Cambridge University Press, 1925. 
WARMING, E. (trans. A. F. POTTER). A handbook of systematic botany. 

The Macmillan Company, 1904. 
WETTSTEIN, R. R. Handbuch der systematischen Botanik. Denticke, 

1911. 



B. GENERAL MANUALS AND CYCLOPEDIAS OF BROAD SCOPE AND 

WIDE USE 

BAILEY, L. H. Manual of cultivated plants. A flora for the identification 
of the most common or significant species of plants grown in the con- 
tinental United States and Canada for food, ornament, utility, and 
general interest, both in the open and under glass. The Macmillan 
Company, 1924. 



372 FLOWERS AND FLOWERING PLANTS 

BAILEY, L. H. The standard cyclopedia of horticulture. A discussion 
for the amateur, and the professional and commercial grower, of the 
kinds, characteristics, and methods of cultivation of the species of 
plants grown in the regions of the United States and Canada for 
ornament, for fancy, for fruit and for vegetables; keys to the natural 
families and genera, descriptions of the horticultural capabilities 
of the states and provinces and dependent islands, and sketches 
of eminent horticulturists. Copiously illustrated with thousands of 
figures, many of them colored. New edition in 3 Vols. The 
Macmillan Company, 1925. 

BRITTON, N. L. and others. North American Flora. A great work pro- 
jected in 34 Vols. to cover all groups of plants. Only one volume, 
and many scattered parts published to date. New York Botanical 
Garden. 

GHAY, A. The genera of the plants of the United States. Illustrated 
by figures and analyses from nature. 2 Vols. G. P. Putnam's Sons, 
1849. 

GRAY, A. Synoptical flora of North America. 2nd Ed. Ivison, Blakemari, 
Taylor Company., 1886. 

GRAY, ASA, and JOHN TORREY. Flora of North America. 2 Vols. 183&-- 
1843. 

GRAY, A. Field, forest and garden botany. A simple introduction to 
the common plants of the United States east of the 100th meridian, 
both wild arid cultivated. Revised and extended by L. H. Bailey. 
American Book Company, 1895. 

REHDER, A. Manual of cultivated trees" and shrubs hardy in North America 
except in the subtropical and warmer temperate regions. The Mac- 
millan Company, 1926. 

C. REGIONAL. MANUALS AND FLORAS (SEE FIG. 211) 

ABRAMS, L. An illustrated flora of the Pacific states. Washington, 
Oregon, California. Every species of ferns, gymnosperms, and flower- 
ing plants known to grow wild in the Pacific states is here illustrated 
and described. 3 Vols., Vol. 1, Stanford Press, 1923. 

BRITTON, N. L. Manual of the flora of the northern states and Canada. 
Includes the ferns, gymnosperms and flowering plants from Newfound- 
land and Labrador to Manitoba, the southern boundary of Virginia, 
Kentucky, and Kansas, and the west boundary of Kansas and Nebraska. 
Has gone through three editions; last edition, Henry Holt & Company, 
1910. 

BRITTON, N. L. and A. BROWN. An illustrated flora of the northern 
states and Canada and the British possessions from Newfoundland 
to the parallel of the south boundary of Virginia and from the Atlantic 
Ocean westward to the 102nd meridian. 3 Vols. 2nd Ed. Charles 
Scribner's Sons, 1913. 

CHAPMAN, A. W. Flora of the southern United States. An abridged 
description of the ferns and flowering plants of Tennessee, North and 
South Carolina, Georgia, Alabama, Mississippi, and Florida, according 



REFERENCE BOOKS, MONOGRAPHS, MANUALS 373 

to the natural system. 3rd Ed. Cambridge Botanical Supply Com- 
pany, 1897. 

COULTER, J. M. Botany of western Texas. A manual of the phanerogams 
and pteridophytes of western Texas. Contributions from the United 
States National Herbarium, Vol. II. 1891-1894. 

COULTER, J. M. and A. NELSON. A new manual of Rocky Mountain 
botany. With Colorado as a center this manual includes Wyoming, 
Yellowstone National Park, Black Hills of South Dakota, most of Mon- 
tana, southern Idaho, eastern Utah and northern New Mexico and 
Arizona. American Book Company, 1909. 

FRYE, T C. and G. B. RIGG. Northwest flora. The gymnosperms and 
flowering plants of Oregon, Idaho, Washington and southwestern 
British Columbia. University of Washington, 1912. 

GRAY, ASA. New manual of botany. See under Robinson and Fernald. 

HOWBLL, THOS. A flora of northwest America. Brief descriptions of all 
the known indigenous and naturalized plants, growing without cultiva- 
tion north of California, west of Utah arid south of British Columbia 
Author, 1903. 

JEPSON, W. L. A manual of the flowering plants of California. Including 
a complete account of the native ferns, gymnosperms and flowering 
plants of the state, and 1,023 original drawings. University of Cali- 
fornia, 1923-1925. 

MACOUN, J. Catalog of Canadian plants. 7 Parts. Geological and 
Natural History Survey of Canada, Montreal, 1883-1902. 

PIPER, C. V. and R. K. BEATTIE. Flora of southeastern Washington and 
adjacent Idaho. New Era Press, 1914. 

PIPER, C. V. and R. K. BEATTIE. Flora of the northwest coast. The 
native ferns, gymnosperms and flowering plants found west of the sum- 
mit of the Cascade Mountains from the 49th parallel south to the 
Calapooia Mountains of the southern border of Lane County, Oregon. 
New Kra Press, 1915. 

ROBINSON, B. L. and M. L. FERNALD. Gray's new manual of botany. 
7th Ed. A handbook of the flowering plants and ferns of the central 
and northeastern United States and adjacent Canada. American Book 
Company, 1908. 

RYDBERG, P. A. Flora of the Rocky Mountains and adjacent plains. 
Includes Colorado, Wyoming, Idaho, Montana, Saskatchewan, Alberta, 
and neighboring parts of Nebraska, North and South Dakota, and 
British Columbia. Author, 1917. 2nd Ed. 1922. 

SMALL, J. K. Flora of the southeastern United States. Describes the 
ferns, gymnosperms, and flowering plants that grow naturally in North 
Carolina, South Carolina, Georgia, Florida, Alabama, Tennessee, 
Arkansas, Mississippi, Louisiana, and Oklahoma and Texas east of the 
100th meridian. 2nd Ed. Author, 1913. 

D. REGIONAL, STATE, AND LOCAL FLORAS, INCLUDING MORE 

OR LESS POPULAR TREATISES 
ABRAMS, L. Flora of Los Angeles and vicinity. The gymnosperms and 

flowering plants of the coast slope of Los Angeles and Orange counties, 

California. New Era Press, 1917. 



374 



FLOWERS AND FLOWERING PLANTS 




SCO 
C3 

3 cu 



II 



REFERENCE BOOKS, MONOGRAPHS, MANUALS 375 

BERGMAN, H. F. Flora of North Dakota. In 6th Biennial Report of the 
Director, North Dakota Soil and Geological Survey, 1912. 

BRITTON, N. L. Catalog of plants found in New Jersey. 1889. 

BRITTON, N. L. Flora of Bermuda. Includes thallophytes and bryophytes 
as well as ferns, gymnosperms and flowering plants. Illustrated. 
Charles Scribner's Sons, 1918'. 

BRITTON, N. L. and C. F. MILLSPAUGH. The Bahama flora. A general 
flora including all major groups of the vegetable kingdom. Authors, 
1920. 

BROWN, S. Alpine flora of the Canadian Rocky Mountains. A popular 
guide to the flora of the Canadian Rockies and Selkirk Mountains, or 
that portion traversed by the Canadian Pacific R^ R. between Banff 
and Glacier. Many illustrations from photographs and water-color 
drawings. G. P. Putnam's Sons, 1907. 

CLEMENTS, F. E. and K. S. Rocky Mountain flowers. An illustrated 
guide for plant lovers and plant users. Twenty- five plates in color and 
twenty-two plates in black and white. The range of this flora is about 
the same as that for Coulter-Nelson flora, but in a general way is useful 
over a much wider area since many of the species occur from the Cana- 
dian Rockies to New Mexico and Arizona. H. W. Wilson Co., 1920. 

COVILLE, F. V. Botany of the Death Valley expedition. A report on the 
botany of the expedition sent out in 1891 by the United States Dep. 
Agr. to make a biological survey of the region of Death Valley, Calif. 
Contributions from the United States National Herbarium, Vol. IV. 
1893. 

DAVIDSON, A. and G. L. MOXLEY. Flora of southern California. The 
ferns, gymnosperms, and flowering plants of southern California as 
limited by Santa Barbara, San Bernardino, Riverside, Imperial, San 
Diego, Orange, and Los Angeles counties. Times-Mirror Press, 1923. 

FAWCETT, WM. and A. B. RENDLE. Flora of Jamaica. Descriptions of 
the flowering plants of the island. 4 Parts. Illustrated. 1910-1912. 

FITZPATRICK, T. J. Manual of the flowering plants of Iowa. 1899. 

GARRETT, A. 0. Spring flora of the Wasatch region. A brief series of 
keys to the gymnosperms and early summer flowering plants of the 
eastern edge of the Great Basin in Utah. 3rd Ed. New Era Press, 
1917. 

GRAVES, C. B. et al. Catalog of the flowering plants and ferns of Con- 
necticut. 1910. 

HALL, H. M. and C. C. A Yosemite flora. Descriptions and simple keys 
for plants in Yosemite National Park. Illustrated. Paul Elder, 1912. 

HENRY, J. K. Flora of southern British Columbia and Vancouver Island, 
with many references to the plants of Alaska and other northern species. 
Gage & Company, 1915. 

HOUSE, H. D. Wild flowers of New York. 2 Vols. 1918. 

JEPSON, W. L. A flora of western middle California. 2nd Ed. Cunning- 
ham, Curtis & Welch, 1911. 

JEPSON, W. L. Manual of the flowering plants of California. Sather Gate 
Bookshop, Berkeley, 1925. 

LOWE, E. N. Plants of Mississippi. 1921. 



376 FLOWERS AND FLOWERING PLANTS 

MACKENZIE, K. K. and B. F. BUSH. Manual of the flora of Jackson County, 

Missouri. 1902. 
MACMILLAN, C. The Metaspermao of the Minnesota valley. Geological 

and Natural History Survey of Minnesota. Botanical Series I. Uni- 
versity of Minnesota, 1892. 
MILLSPAUGH, C. F. and L. W. NUTTALL. Flora of Santa Catalina Island, 

California. Illustrated. Includes all major groups. Field Museum of 

Natural History, Pub. 212, 1923. 
NELSON, A. Spring flora of the intermountain states. For Colorado, 

Wyoming, northern Utah, Montana, Idaho (except the northern part). 

Ginn & Company, 1912. 
MOHR, CHAS. Plant life of Alabama. Contributions from the United 

States National Herbarium. Vol. VI. 1901. 
PEPOON, H. S. An annotated flora of the Chicago region. 1927. 
PETERSEN, N. F. Flora of Nebraska. A list of the ferns, conifers, and 

flowering plants of the state, with keys for their identification. 3rd 

Ed. Author, 1923. 
PIPER, C. V. Flora of the State of Washington. Contributions from the 

United States National Herbarium. Vol. XI. Illustrated. 1906. 
RYDBERG, P. A. Flora of Colorado. Bull. 100, Colo. Agr. Exp. Sta., 1905. 
RYDBERG, P. A. Catalog of the flora of Montana and the Yellowstone 

National Park. Memoirs of the New York Botanical Garden. Vol. I. 

1900. 
RYDBERG, P. A. Flora of the Black Hills of South Dakota. Contributions 

from the United States National Herbarium. Vol. III. No. 8. 1896. 
SCHAFFNER, J. H. Field manual of the flora of Ohio. R. G. Adams Com- 
pany, Columbus, O., 1928. 
STANDLEY, P. C. Flora of Glacier National Park. Contributions from the 

United States National Herbarium. Vol. XXII, Part 5. 1921. 
STEVENS, G. T. An illustrated guide to the flowering plants. For the 

plants of the middle Atlantic and New England states, the descriptive 

text written in popular language. Copiously illustrated. Dodd, Mead 

& Company, 1910. 
TIDESTROM, I. Flora of Utah and Nevada. Contributions from the United 

States National Herbarium, Vol. 25. 1925. 
WIEGAND, K. M. and A. J. EAMES. The 'flora of the Cayuga lake basin, 

New York. 1926. 

WOOTON, E. O. and P. C. STANDLEY. Flora of New Mexico. Contribu- 
tions from the United States National Herbarium Vol. XIX. 1915. 

E. MANUALS FOR TREES, TREE BOOKS 

APGAR, A. C. Trees of the northern United States, their study, description 
and determination. American Book Company, 1892. 

BAILEY, L. H. The cultivated evergreens. A handbook of the conifers 
and most important broadleaved evergreens planted for ornament in 
the United States and Canada. Includes notes on insect pests, dis- 
eases, and injuries, adaptation, cultivation. Illustrated. The Mac- 
millan Company, 1923. 



REFERENCE BOOKS, MONOGRAPHS, MANUALS 377 

BAILEY, L. H. Manual of cultivated plants. Contains many trees and 
shrubs. The Macmillan Company, 1924. 

BLAKESLEE, A. F. and C. D. JARVIS. Trees in winter. Their study, plant- 
ing, care, and identification. Illustrated. The Macmillan Company, 
1913. 

BRITTON, N. L. North American trees. Henry Holt & Company, 1908. 

BROWN, H. P. Trees of New York state, native and naturalized. Illus- 
trated. Tech. Pub. 15, The New York State College of Forestry, 1921 

BURNS, G. P. and C. H. OTIS. The trees of Vermont. Illustrated. Bull 
194, Vt. Agr. Exp. Sta., 1916. 

CLEMENTS, F. E., C. O. ROSENDAHL, and F. K. BUTTERS. Minnesota 
trees and shrubs. An illustrated manual of the native and cultivated 
woody plants of the state. Report, Minnesota Botanical Survey, IX, 
1912. 

CURTIS, C. C. A guide to the trees. Grcenberg, N. Y., 1925. 

EMERSON, A. I. and C. M. WEED. Our trees and how to know them. A 
guide to the recognition of trees at any season and notes on their charac- 
teristics, distribution, and cultivation. J. B. Lippincott Company, 1908. 

GIBSON, H. H. American forest trees. Descriptions of many American 
trees, with extensive notes with reference to their properties and values 
in forestry. Illustrated. Hardwood Record, 1913. 

HOUGH, R. B. Handbook of the trees of the northern states and Canada 
east of the Rocky Mountains. Many halftone illustrations and distri- 
bution maps. Author, 1907. 

HUNTINGTON, A. O. Studies of trees in winter. A description of the 
deciduous trees of northeastern America in their winter condition. 
Knight and Millet, 1905. 

ILLICK, J. S. Pennsylvania trees. 4th Ed. Illustrated. Bull. 11, Penn- 
sylvania Department of Forestry, 1923. 

JEPSON, W. L. The trees of California. A working manual of value to 
botanists, foresters, horticulturists, lumbermen, teachers, travelers, 
and nature students. Cunningham, Curtis & Welch, 1909. 

JEPSON, W. L. The silva of California. Memoirs, University of California 
II. 1910. 

KEELER, H. L. Our native trees and how to identify them. A popular, 
illustrated study of the habits and peculiarities of many eastern and 
northern trees. Charles Scribner's Sons, 1915. 

LONOYEAR, B. O. Trees and shrubs of the Rocky Mountain region. With 
keys and descriptions for their identification. G. P. Putnam's Sons, 
1927. 

MATHEWS, F. S. Fieldbook of American trees and shrubs. A concise, 
illustrated description of the character and color of species common 
throughout the United States, with maps to show their general distri- 
bution. G. P. Putnam's Sons, 1915. 

OTIS, C. H. Michigan trees. A handbook of the native and most impor- 
tant introduced species. Illustrated. University of Michigan, 1913. 

POOL, R. J. Handbook of Nebraska trees. A guide to the native and most 
important introduced species. The Botanical Survey of Nebraska, 
N. S. No. 3, 1909. 2nd. Ed. 1929. 



378 FLOWERS AND FLOWERING PLANTS 

PRATT, M. B. Shade and ornamental trees of California. California 
State Board of Forestry. 1921. 

RAMALEY, F. Wild flowers and trees of Colorado. A. A. Greenman, 1909. 

REHDEB, A. Manual of cultivated trees and shrubs, hardy in North 
America except in the subtropical and warmer temperate regions. 
The Macmillan Company, 1926. 

ROCK, J. F. The indigenous trees of the Hawaiian Islands. Illustrated 
Author and patrons, Honolulu, 1913. 

ROGERS, J. E. The tree book. A popular guide to a knowledge of the trees 
of North America, their uses and cultivation. Illustrated. Doubleday 
Page & Company, 1907. 

SARGENT, C. S. The silva of North America. A description of the trees 
which grow naturally in North America exclusive of Mexico. Copi- 
ously illustrated by fine engravings. 14 Vols. Houghton, Mifflin 
Company, 1891-1902. 

SARGENT, C. S. Manual of the trees of North America exclusive of Mexico 
Illustrated. This is really an abridgment of the author's silva 2nd 
Ed. Houghton, Mifflin Company, 1922. 

SCHAFFNER, J. H. Field manual of trees. R. G. Adams Company, Colum- 
bus, O., 1926. 

SCOTT, C. A. and F. C. GATES. Trees in Kansas. State Board of Agricul- 
ture, 1928. 

SMALL, J. K. Florida trees. A handbook of the native and naturalized 
trees of Florida. Author, 1913. 

STANDLEY, P. C. Trees and shrubs of Mexico. Contributions from the 
United States National Herbarium. Vol. XXIII. 1920-1926. 

SUDWORTH, G. B. Forest Trees of the Pacific Slope. Illustrated. U. S 
Dept Agr. Forest Service, 1908. 

SUDWORTH, G. B. Check list of the forest trees of the United States, their 
names and ranges. An authoritative work for the forester and tree 
student. Miscellaneous Circ. 92, U. S. Dept. Agr., 1927. 

TRELEASE, WM. Winter botany. Plant materials of decorative gardening. 
Author, 1918. 

TRELEASE, WM. The American oaks. Includes the oaks of both North 
and South America. Memoirs, National Academy of Sciences. Vol. 
XX, 1924. 

F. POPULAR WORKS ON FLOWERS 

ARMSTRONG, M. and J. J. THORNBER. Field book of western wild flowers. 

A guide to the commoner wild flowers west of the Rocky Mountains. 

G. P. Putnam's Sons, 1915. 
BROWN, S. Alpine flora of the Canadian Rocky Mountains. A popular 

guide to the flora of the Banff to Glacier area. Colored illustrations. 

G. P. Putnam's Sons, 1907. 
CLEMENTS, F. E. and E. S. Rocky Mountain flowers. An illustrated 

guide, useful throughout the Rocky Mountain region, but particularly 

helpful in the central Rockies. H. W. Wilson Company. 1920. 
CLEMENTS, F. E. and E. S. Flower families and ancestors. H. W. Wilson 

company, 1928. 



REFERENCE BOOKS, MONOGRAPHS, MANUALS 379 

CLEMENTS, E. S. Wild flowers of the west. The National Geographic 
Magazine, May, 1927. 

CLEMENTS, E. S. Flowers of Coast and Sierra. H. W. Wilson Company, 
1928. 

CLEMENTS, F. E. and W. J. SHOWALTER. The family tree of the flowers. 
The National Geographic Magazine, May, 1927. 

DANA, W. S. How to know the wildflowers. A guide to the names, haunts, 
and habits of our native wildflowers. Charles Scribner's Sons. 

DURAND, H. My wild flower garden. G. P. Putnam's Sons. 

KEELER, H. L. Our early wild flowers. A study of the herbaceous plants 
blooming in early spring in the northern states. Charles Scribner's 
Sons, 1916. 

KEELER, H. L. The wayside flowers of summer. A study of the con- 
spicuous herbaceous plants blooming upon our northern roadsides dur- 
ing the months of July and August. Charles Scribner's Sons, 1917. 

MATHEWS, F. S. Field book of American wild flowers. Character and 
habits, description of colors, pollination, etc. G. P. Putman's Sons, 
1927. 

PARSONS, M. E. The wild flowers of California. Their names, haunts, 
and habits. 4th Ed. Payot, Upham & Company, 1902. 

RAMALEY, F. Wild flowers and trees of Colorado. A. A. Greenman, 1909. 

SAUNDERS, C. F. Useful wild plants of the United States and Canada. 
Robert M. McBride & Company, 1920. 

SHOWALTER, W. J., M. E. EATON, G. GROSVENOR, and E. J. GESKE. The 
book of wildflowers. An introduction to the ways of plant life, together 
with biographies of 250 representative species, and chapters on state 
flowers and familiar grasses. National Geographic Society, 1924. 

TAYLOR, NORMAN. A guide to the wildflowers. Greenberg, N. Y. 1928. 

WEED, C. M. Wild flower families. The haunts, characteristics and family 
relationships of the herbaceous wild flowers, with suggestions for their 
identification. Illustrated. J. B. Lippmcott Company, 1908. 

WICKSON, E. J. California garden flowers. Shrubs, trees, and vines, 
being mainly suggestions for working amateurs. 2nd Ed. Pacific 
Rural Press. 1923. 

WRIGHT, R. The practical book of outdoor flowers. Deals largely with 
the use of flowering plants in outdoor gardens. Copiously illustrated. 
J. B. Lippincott Company, 1924. 

G. BOOKS ON CULTIVATED PLANTS 

BAILEY, L. H. Manual of cultivated plants. A flora for the identification 
of the most common or significant species of plants grown in the con- 
tinental United States and Canada for food, ornament, utility, and 
general interest, both in the open and under glass. The Macmillan 
Company, 1924. 

BAILEY, L. H. The cultivated evergreens. A handbook of the coniferous 
and most important broadleaved evergreen plants for ornament in 
the United States and Canada. The Macmillan Company, 1923. 

BAILEY, L. H. The standard cyclopedia of horticulture. A discussion 
for the amateur, the professional and commercial grower of plants for 



380 FLOWERS AND FLOWERING PLANTS 

any purpose. New edition in 3 Vols. The Macmillan Company, 
1924. . 

BROWN, H. B. Cotton. History, species, varieties, morphology, breeding, 
culture, diseases, marketing, and uses. McGraw-Hill Book Company, 
Inc., 1927. 

BURT-DAVY, J. Maize. Its history, cultivation, handling, and uses, for 
farmers, agriculturists, and teachers of nature study. Longmans, 
Green and Company. 1914 

CHENEY, R. H. Coffee. An economic monograph. New York University 
Press, 1925. 

COIT, J. E. Citrus Fruits. The Macmillan Company, 1915. 

COPELAND, E. B. The Coconut. 2nd Ed. The Macmillan Company, 
1921. 

DECANDOLLE, A. (English Ed.) Origin of cultivated plants. D. Apple- 
ton & Company, 1885. 

DYKES, W. R. The Genus Iris. Cambridge University Press, 1913 

EISEN, G. The fig: its history, culture, and curing. Div. Pom. IT. S. Dept 
Agr., Bull 9, 1901. 

GARDNER, V. R , F. C. BRADFORD and II. D. HOOKER The fundamentals 
of fruit production. McGraw-Hill Book Company, Inc , 1922 

HUNTER, H. Oats: their varieties and characteristics. A practical hand- 
book for farmers, seedsmen, and students. E. Bern, 1924. 

HUTCHESON, T. B. and T. K. WOLFE. The production of field crops 
McGraw-Hill Book Company, Inc. 1924. 

JEPSON, W. L. A flora of the economic plants of California for agricultural 
purposes. Crop plants, weeds, honey plants, poisonous plants, medici- 
nal plants, native timber trees, and spring plants. University of 
California. 1924. 

MILLAIS, J. G. Rhododendrons. 2 Vols. Longmans, Green and Com- 
pany, 1917-1924. 

PEMBERTON, J. H. Roses: their history, development and cultivation 
2nd Ed. Longmans, Green and Company. 1920. 

POPENOE, W. Manual of tropical and subtropical fruits, excluding the 
banana, coconut, pineapple, citrus fruits, olive, and fig. The Mac- 
millan Company, 1920. 

ROBBINS, W. W. The botany of crop plants. A text and reference book. 
2nd Ed. Blakiston's, 1924. 

STUART, WM. The potato, its culture, uses, history, and classification 
J. B. Lippincott Company, 1923. 

THOMPSON, H. C. Vegetable crops. McGraw-Hill Book Company, Inc, , 
1923. 

TRELEASE, WM. Plant materials of decorative gardening. The woody 
plants. Author, 1917. 

H. BOOKS ON GRASSES 

BEAL, W. J. Grasses of North America. 2 Vols. Henry Holt & Companv. 

1896. 
CARLETON, M. A The small grains. The Macmillan Company, 1916. 



REFERENCE BOOKS, MONOGRAPHS, MANUALS 381 

CHASE, A. First book of grasses. The structure of grasses explained for 

beginners. The Macmillan Company, 1922. 

FRANCIS, M. E. The book of grasses. Doubleday, Page & Company. 
HACKEL, E. (trans. SCRIBNER, F. L. and E. A. SOUTHWORTH). The true 

grasses. Henry Holt & Company. 1890. 
HITCHCOCK, A. S. A textbook of grasses. With especial reference to the 

economic species of the United States. The Macmillan Company, 

1914. 
HITCHCOCK, A. S. The genera of grasses of the United States. With 

special reference to the economic species. U. S. Dept. Agr., Bull. 772 

1920. 

HUNT, T. F. The cereals of America. Orange Judd, 1905. 
MACSELF, A. J. Grass. A new and thoroughly practical book on grasses 

for ornamental lawns and all purposes of sports and games. C. Palmer, 

London, 1924. 

MONTGOMERY, E. G. The corn crops. The Macmillan Company, 1913. 
Several states have issued bulletins dealing with the classification of the 
grasses found within the respective areas. 

I. VALUABLE WORKS PUBLISHED SINCE THE FIRST EDITION 
OF THIS BOOK 

ARBER, AGNES. Herbals: their origin and evolution. 2nd Ed. The 

Macmillan Company, 1938. 
BAILEY, L. H. How plants get their names. The Macmillan Company, 

1933. 

BAILEY, L. H. The garden of larkspurs. The Macmillan Company, 1939. 
BAKER, M. F. Florida wild flowers. The Macmillan Company, 1938. 
BLOMQUIST, H. L. and H. J. COSTING. A guide to the spring and early 

summer flora of Piedmont, N. C. % Authors, Durham, 1936. 
BORG, J. Cacti. The Macmillan Company, 1937. 
CLEMENTS, F. E. and E. S. Flower pageant of the Midwest. National 

Geographic Magazine, August, 1939. 
CORREVON, H. Rock garden and alpine plants. The Macmillan Company, 

1930. 
DEGENER, O. The new illustrated flora of the Hawaiian Islands. Author, 

1933. 

ELLIOTT, C. Rock garden plants. Edward Arnold & Co., 1936. 
FASSETT, N. C. A manual of aquatic plants. The McGraw-Hill Book 

Company, Inc., 1940. 
FREAR, M. D. and O. G. McLEAN. Flowers of Hawaii. Dodd. Mead & 

Company, Inc., 1938. 
GABRIELSON, I. N. Western American alpines. The; Macmillan Company, 

1932. 
GATES, F. C. Flora of Kansas. Contnb. 391, Dept. Botany, Kansas State 

Coll., Manhattan, 1940. 

GILKEY, HELEN M. Handbook of northwest flowering plants. Metro- 
politan Press, 1936. 
GREEN, CHARLOTTE H. Trees of the South. University of North Carolina 

Press 1939. 



382 FLOWERS AND FLOWERING PLANTS 

HARLOW, W. M. and E. S. HARRAR. Textbook of dendrology. McGraw- 
Hill Book Company, Inc., 1937. 

HESS, K. P. Textile fibers and their use, J. B. Lippincott Company, 1936. 

HILL, A. F. Economic botany. McGraw-Hill Book Company, Inc. 
1937. 

HITCHCOCK, A. S. Manual of the grasses of the United States. Miscel- 
laneous Pub. 200, U.S. Dept. Agr., 1935. 

HITCHCOCK, A. S. Manual of the grasses of the West Indies. Miscel- 
laneous Pub. 240, U.S. Dept. Agr., 1936. 

HOUSE, H. D. Wild flowers. 364 Colored Illustrations. The Macmillan 
Company, 1934. 

JOHNSON, A. M. Taxonomy of the flowering plants D. Appleton-Ccntury 
Company, Inc., 1931. 

JONES, S. G. Introduction to floral mechanism. Chemical Publishing 
Company of New York, Inc., 1939. 

KIRKWOOD, J. E. Northern Rocky Mountain trees and shrubs. Stanford 
University Press, 1930. 

MACFARLANE, J. M. The evolution and distribution of flowering plants. 
Noll Printing Company, 1933. 

MrMiNN, H. E. An illustrated manual of California shrubs. J. W. 
Stacey, Inc., 1939. 

IVlADSGER, O. P. Edible wild plants. The Macmillan Company, 1939. 

MUENSCHER, W. C. Poisonous plants of the United States. The Mac- 
millan Company, 1939. 

MUENSCHER, W. C. Weeds. The Macmillan Company, 1935 

MUNZ, P. A. A manual of southern California botany. J W. Stacey, Inc , 
1935. 

PREECE, W. H. A. North American rock plants. The Macmillan Com- 
pany, 1937. 

PRESTON, R. J. Rocky Mountain trees. Iowa State College Press, 1940. 

ROBBINS, W. W. and F. RAMALEY. Plants useful to man. 2nd Ed P. 
Blakiston's Son & Company, Inc., 1937. 

ROHDE, E. S. Herbs and herb gardening. The Macmillan Company, 1937. 

ROUNTREE, L. Flowering shrubs of California. Stanford University Press, 
1939. 

RYDBERG, P. A. Flora of the prairies and plains of central North America. 
New York Botanical Garden, 1932. 

ST. JOHN, H. Flora of southeastern Washington and adjacent Idaho. 
Student's Book Corporation, 1937. 

SHARPLES, ADA W. Alaska wild flowers. Stanford University Press, 1938. 

SILVEUS, W. A. Texas grasses. Author, San Antonio, 1933. 

SLATE, G. L. Lilies for American gardens. Charles Scribner's Sons, 1939. 

STANFORD, E. E. Economic plants. D. Appleton-Century Company, 
Inc., 1934. 

STEMEN, T. R. and W. S. MYERS. Oklahoma flora. Harlow Publishing 
Company, 1937. 

STEVENS, G. A. Garden flowers in color. The Macmillan Company, 1935. 

STEYERMARK, J. A. Spring flora of Missouri. Missouri Botanical Garden, 
and Field Museum of Natural History, 1940 



REFERENCE BOOKS, MONOGRAPHS, MANUALS 383 

IHORNBER, J. J. and F. BONKER. The fantastic clan (the Cactus family). 
The Macmillan Company, 1932. 

TIDESTROM, I. and T. KITTELL. The flora of Arizona and New Mexico. 
Contrib. U. S. National Herbarium, Vol. 25, 1940 

U.S. Department of Agriculture, Forest Service. Range plant handbook. 
U.S. Government Printing Office, 1937. 

VAN DERSAL, W. R. Native woody plants of the United States. Miscel- 
laneous Pub. 303, U.S. Dept. Agr., 1938. 

VAN LAREN, A. J., E. J. LABARRE, and S E. HASELTON Succulents other 
than cacti. Abbey San Encino Press, 1935. 

WODEHOUSE, R. P. Pollen grains. McGraw-Hill Book Company, Inc , 
1935. 

WOODCOCK, H. D. and J. COUTTS. Lilies. Charles Scrihner's Sons, 1935. 



GLOSSARY 

Abaxial. On tho side away from the axis. 

Acaulescent. Without a stem; or with very short, scarcely evident stem. 
Achene. A small, dry, hard, one-chambered, one-seeded fruit. 
Actinomorphic. Said of a flower having radial symmetry; regular; more or 

less star-shaped. 

Acuminate. Narrowly tapering to a sharp point. 
Acute. Tapering more broadly than acuminate to a sharp point. 
Adaxial. Facing the primary axis. 
Adnate. United, synonymous with adherent, referring to the union of one 

organ with another, as ovary with receptacle, and stamen with corolla. 
Adventitious. Appearing in other than the usual place, as roots springing 

from cuttings of the stem or from loaves. 
Aggregate fruit. Fruit formed by the coherence of the pistils that were 

distinct in the flower, as in raspberry. 

Albuminous. Provided with albumen or endosperm or perisperm, or both. 
Allogamy. Cross-pollination. 
Alternate. Arranged in a zigzag manner, as when leaves are on opposite 

sides of the stem but at different levels. 
Ament. A catkin, a type of pendulous, scaly spike, as in willows and 

birches. 

Amentiferous. Bearing aments or catkins. 
Analytical key. An orderly arrangement of contrasting or comparable 

statements about plants or plant structures, leading to identification 
Anatropous. Bent over or inverted; said of an ovule with the hilum and 

micropyle near together at one end, and opposite the chalaza. 
Androecium. Collective term for the stamens. 
Androgynous. Bearing starmnate and carpellatc flowers in the same 

inflorescence. 

Anemophilous. Wirid-polliiiated; literally, "wind-loving." 
Annual. Of one year's growth; a plant that dies after one year's activity. 
Anther. The pollen-bearing organ of a flower; compare with filament. 
Anthesis. The period of opening of the flower; the period of pollination. 
Apetalous flower. Lacking petals. 
Apocarpous. Composed of distinct or separate carpels; compare with 

syncarpous. 
Arachnoid. Having the appearance of a cobweb; composed of entangled 

hairs. 

Aril. A small appendage from or around the hilum of a seed 
Aristate. Awned; bearing a stiff, bristly appendage 
Articulate. Jointed; easily separating at nodes or joints, as in spikelets of 

grasses. 
Artificial classification (key). A classification or key that does not consider 

natural relationships. 

385 



386 FLOWERS AND FLOWERING PLANTS 

Ascending. Growing obliquely upward, or curving upward during growth. 

Applied to branches, hairs of stems, and ovules. 
Attenuate. Drawn out into a long, slender point. 
Auricle. An ear-shaped appendage, as at the top of the leaf sheath in 

grasses. 

Auriculate. With auricles or "ears," as in hastate and saggitate leaves. 
Autogamy. Self-pollination. 
Awn. A stiff, bristle-like appendage; a beard. 
Axial. Belonging to the axis. 

Axil. The angle formed by a leaf with the stem to which it is attached. 
Axillary. Situated in the axil of a leaf. 
Axis. The line running lengthwise through the center of a,n organ, as of a 

flower or a stem; also applied to the stem itself, and the torus or recep- 
tacle of a flower. 

Baccate. Having the nature of a berry. 
Banner. The large, broad, upper petal in the flower of a legume (same as 

standard). 
Beaked. Furnished with a prominent tip, as the persistent base of the 

style in some spike-rushes. 
Beard. An awn, as in the grasses. 
Berry. A fleshy fruit, with one or more carpels and usually several or many 

seeds. 

Bidentate. Two-toothed. 
Biennial. A plant that lives through two growing seasons, fruiting the 

second year, and then dies. 

Bifid. Two-cleft; forked into two slender limbs to near the middle. 
Bilabiate. Two-lipped, referring especially to the corolla. 
Bilocular. Two-celled, as applied to an ovary or an anther. 
Bipinnate. Twice-pinnate, referring to compound leaves. 
Bipinnatifid. Twice-pinnatifid. 

Bisexual. Having both stamens and carpels (a "perfect" flower). 
Blade. The principal part of a leaf, usually broad, flat, thin, green (compare 

with petiole). 

Bract. A much reduced leaf, as of an inflorescence or rhizome. 
Bracteate. Furnished with bracts. 

Bud. An undeveloped shoot or a shoot in the resting condition. 
Bulb. A short, thick stem, most of the leaves of which are thickened and 

stored with reserve food. 

Bulbil. Small bulbs borne singly or in clusters. 
Bulbous. Of the character of a bulb. 
Bullate. Blistered or puckered. 
Bundle scars. Scars left in a leaf scar by the severance of vascular bundles 

at leaf fall. 

Caducous. Falling off very early, as the sepals and petals of certain flowers. 
Caespitose. Tufted; growing in tufts, as in many grasses. 
Calyx. The outer set of perianth segments of a flower. 
Calyx tube. The tube of a gamosepalous calyx. Sometimes used for the 

hypanthium or receptacle of perigynous and epigynous flowers. 
Campanulate. Bell-shaped. 



GLOSSARY 387 

Campylotropous. Bent so as to bring the hilum, micropyle, and chalaza 

close together, said of ovules. 
Canescent. Bearing a hoary, grayish pubescence. 
Capillary. Hair-like, thread-like, filiform. 
Capitate. Head-like; collected into a dense cluster. Like a pinhead, as in 

gland-tipped hairs; the inflorescence of composites. 
Capsular. Belonging to or having the character of a capsule. 
Capsule. A dry dehiscent fruit (pod); with two or more carpels, usually 

with several or many seeds. 
Carpel. The ovuliferous organ of the flower; a simple pistil or one of the 

segments of a compound pistil. 

Caryopsis. The grain (fruit) of grasses; one-seeded, iridehiscent. 
Catkin. An ament; a scaly, spicate inflorescence, as in willows and birches. 
Caudate. Bearing a tail-like appendage. 
Chaff. Small, more or less dry, membranaceous bract; especially the small 

bracts at the base of the disk flowers of some composites. 
Chalaza. The basal part of an ovule where the stalk or funiculus enters. 
Circinate. Said of a leaf that is coiled or rolled from the tip toward the 

base with the lower surface outermost. 
Circumscissile. Dehiscing or separating by a circular zone, as the capsule of 

Plantago. 
Cladophyll. A branch modified in the form of a leaf; a leaf-like stem as in 

certain species of A sparagus. 

Clasping. Said of a sessile leaf in which the blade partly invests the stem. 
Clavate. Club-shaped; gradually thickened inward. 

Claw. The narrow stalk of some petals, as in mustard, resembling a petiole. 
Cleistogamous. Self-pollinated or self-fertilized in the bud stage, the 

flowers not opening, as in violets. 

Coherent. Fused or united, when the organs are of the same kind. 
Coleoptile. The sheath surrounding the young stem (plumule) in grasses. 
Coleorhiza. The sheath surrounding the radicle of grasses. 
Collateral. Placed side by side, as some carpels and ovules, or as the 

glumes of some grasses, or as xylem and phloom in certain vascular 

bundles. 
Column. That part of the flower of an orchid which is formed by the union 

of the style and the filaments and which supports the anthers and the 

stigma. 
Complete flower. A flower with all parts represented, sepals, petals, 

stamens, pistil. 
Compound. Composed of a number of similar united parts, as carpels in 

a syncarpous gynoecium (compound pistil), or divided into a number 

of similar parts or divisions, as the leaflets of ''compound" leaves. 
Conduplicate. Said of a leaf in which the blade is folded lengthwise 

along the midrib, the two halves face to face, with the lower surfaces 

outermost. 
Connate. Said of leaves in which the bases of two opposite leaves appear 

to have fused about the stem. 
Connivent. Coming together; the converging or bending toward one 

another of two or more similar organs (anthers). 



388 FLOWERS AND FLOWERING PLANTS 

Convolute. Said of a leaf in which the blade is rolled lengthwise from side 

to side like a scroll. 

Cordate. Heart-shaped, referring to the base of a leaf. 
Conn. A short, erect, thick, solid, underground stem, as in Cyclamen, 

Crocus, with stored food. 

Corolla. The inner, colored perianth segments of a flower. 
Corona. A collar-like or tubular appendage of the corolla, as in Narcissus. 
Corymb. A flat-topped racemose inflorescence, the main axis of which 

is elongated, but the pedicels of the older flowers longer than those of 

younger flowers. 

Corymbose. Of the nature or form of a corymb 
Crenate. Scalloped, or with broad rounded teeth. 
Crown. The tubular or ring-like appendage of a corolla as in Narcissus; 

or the top or stem part of a fleshy taproot, as in carrot, parsnip. 
Culm. The erect stem of grasses. 
Cuneate. Wedge-shaped, usually narrow, but broader above the base, 

with the straight sides tapering toward the base. 
Cuspidate. Ending with a sharp rigid point. 
Cyathium. The type of inflorescence found in Euphorbia 
Cyme. A determinate inflorescence, in which the central or apical flower 

opens first. 

Cymose. Of the form or nature of a cyme. 
Deciduous. Falling off, not persistent. 

Decumbent. Growing flat along the ground, but with the tip ascending. 
Decurrent. The blade appearing to continue down the sides of the stem, 

as in a leaf. 

Deltoid. Triangular or like a delta. 
Dentate. With sharp spreading teeth. 
Diadelphous. Said of stamens when united into two sets. 
Diandrous. Said of flowers having two stamens. 
Dicarpellate. Composed of two carpels said of a gyno3cium (same as 

bi- or dicarpellary). 
Dichogamous. Said of flowers in which stamens and pistils mature at 

different times. 
Diclinous. Bearing the aiidnjwium (stamens) and the gyncrcium (pistils) 

in separate flowers. 
Didymous. Twin; occurring in pairs. 

Didynamous. Having the stamens in two unequal sets (as in mustards). 
Digitate. Veined, lobed, or divided as fingers radiating from the palm. 
Dioecious. Bearing the stammate flowers on one individual and the car- 

pellate on another of the same species (as in willows). 
Disk. An outgrowth (often glandular) of the receptacle or hypanthium; 

hypogynous or epigynous according to the position of the ovary. Also 

used in referring to the common receptacle of the head of composites. 
Dissected. Divided into many slender segments. 
Distichous. In two rows, on opposite sides of the stem, said of leaves, the 

two rows lying in the same vertical plane. 

Divided. Cut or separated nearly to the base or to the midrib, as in a leaf. 
Double flower. A flower in which some or all of the stamens and carpels are 

transformed into perianth segments. 



GLOSSARY 389 

Drupaceous. Of the nature or texture of a drupe. 

Druj>e. A simple fleshy fruit, from a single carpel, usually one-seeded, with 

fleshy mesocarp and stony endocarp. 
Elliptical. Like an ellipse, broadest at the middle, tapering broadly and 

evenly toward each end. 
Emarginate. Decidedly notched at the tip. 
Endocarp. The inner layer of a fruit. 
Endogenous. Growing from the inside; said of the growth of stems in 

thickness. 

Endosperm. The tissue with stored food, or "albumen" of a seed. 
Entire. Without marginal serrations or teeth. 

Entomophilous. Insect-loving, referring to insect pollination; insect- 
pollinated. 
Epicotyl. That portion of an embryo above the cotyledonary node; the 

plumule. 

Epigynous. Borne upon or on top of the ovary or gynoecium. 
Epipetalous. Borne upon the petals or the corolla tube, referring to stamens. 
Exocarp. The outer layer of a fruit. 

Exserted. Projecting beyond the summit of, as stamens beyond the petals. 
Extrorse. Facing outward from the center of the flower, as anthers. 
Fertilization. The fusion of gametes, especially heterogametes. 
Filament. The stalk supporting the anther of a stamen (see anther). 
Filiform. Like a filament or thread. 
Fimbriate. Fringed along the edge. 
Floccose. With tufts of soft silky hair. 
Floret. A small flower, as in the spikelets of grasses or the heads of 

composites. 

Foliaceous. Having the character of a leaf. 
Follicle. A dry fruit formed from a single carpel arid usually dehiscing 

along the ventral suture, usually several-seeded. 
Free. Distinct, not united, as of floral organs. 
Fruit. The seed-bearing organ of a plant. 
Fruticose. Shrubby; shrub-like. 

Fugacious. Falling off early, early deciduous; ephemeral; evanescent. 
Funiculus. The stalk of an ovule, by which it is attached to the placenta,. 
Fusiform. Spindle-shaped. 

Galea. A hooded or helmet-shaped sepal or petal, as in Aconitum. 
Gal eat e. Shaped like a hood or helmet; furnished with a galea. 
Gamopetalous. Having united petals; referring to a sympetalous corolla. 
Gamosepalous. Having united sepals, synscpalous. 
Geitonogamy. Pollination between flowers of the same individual. 
Gibbous. Swollen at the base. 
Glabrous. Not hairy. 

Glabrate. Somewhat glabrous, or becoming glabrous. 
Glandular. Supplied with glands. 

Glaucous. Covered with a whitish or bluish "waxy bloom" that rubs off. 
Glumaceous. Bearing glumes; of the character of glumes. 
Glumes. Rigid, chaff-like or scale-like bracts, referring especially t(^ the 

two empty bracts at the base of the spikelet in grasses. 
Glutinous. Sticky or mucilaginous. 



390 FLOWERS AND FLOWERING PLANTS 

Grain. The fruit or caryopis of grasses. 

Gyncecium. A carpel or an aggregation of carpels, free or united. 
Hastate. Halberd-shaped or spear-shaped with auricles turned outward. 
Head. The inflorescence or capitulum of composites; a compact inflores- 
cence. 
Hermaphrodite. Bisexual; having the androocium and the gyncocium in 

the same flower. 

Hesperidium. The fruit of the orange and other citnis plants. 
Hilum. The scar on a seed, marking the point where the seed broke from 

the stalk. 

Hirsute. With stiff hairs. 
Hispid. With bristly hairs. 
Hypanthium. The tube of the receptacle upon which the calyx, corolla, and 

stamens are borne; " calyx tutye"; perianth tube. 
Hypocotyl. The part of an embryo below the cotyledons and including the 

cotyledonary node; the stem of the embryo. 
Hypogynous. Borne beneath or below the gynoocium or ovary, referring 

to stamens, petals, sepals, and disk. 
Imbricate. Overlapping like tiles of a roof, referring to sepals and petals in 

the bud. 

Imperfect flower. A flower lacking stamens or pistils; a unisexual flower. 
Incised. Margin with deeply cut, irregular or jagged teeth. 
Incomplete flower. A flower lacking one or more of the four regular sets of 

parts. 
Indefinite. Inconstant in number; applied also to the continuous growth 

in length of a racemose inflorescence. 

Indehiscent. Not splitting open; remaining closed, as a drupe or an achcno. 
Indeterminate. Of indefinite growth, as a racemose inflorescence. 
Indigenous. Native to a region. 
Inferior. Below, usually referring to the position of the ovary in an epigy- 

nous flower. 
Inflexed. Said of a leaf in which the upper part of the blade is bent over the 

lower part; same as reclinate. 

Inflorescence. A flower cluster, such as a panicle, spike, or raceme. 
Integument. The jacket of an ovule. 

Internode. Part of a stem lying between two successive nodes. 
Interrupted. Broken or irregular in arrangement, said of inflorescences or 

leaves. 

Introrse. Facing inward or facing the stigma, referring to anthers. 
Involucel. A small involucre, as the bracts subtending the secondary 

umbels in the Umbelliferae. 
Involucral. Belonging to the involucre. 
Involucrate. Bearing an involucre. 
Involucre. Cluster of bracts subtending an inflorescence, as in the heads 

of composites or in the umbels of umbellifers. 
Involute. Said of a leaf in which the two sides are rolled lengthwise over 

the upper surface toward the midrib. 

Irregular. Differing in size and shape; unsymmetrical, referring to flowers. 
Keel. A prominent dorsal rib or ridge, as in some carpels or in glumes of 

grasses; the lower petals of the flowers of a legume. 



GLOSSARY 391 

Labiate. Lipped, as the corolla of mints. 

Lanceolate. Lance-shaped, broadest below the middle and tapering 
gradually to the apex. 

Lamina. The expanded part of a leaf; same as the blade. 

Leaf scar. A scar left on a twig at the point from which a leaf falls. 

Leaflet. A segment of a compound leaf. 

Legume. The pod of members of the pea family, a pod dehiscent along 
both sutures. 

Leguminous. Having the character of a legume or of a leguminous plant. 

Lemma. The outer (lower) bract of the floret of grasses. 

Lenticel. A porous spot in the periderm of woody plants, usually rich in 
cork. 

Ligulate. Strap-shaped or tongue-shaped, like the corolla of a flower of the 
dandelion or the ray flowers of a sunflower. 

Ligule. The strap-shaped part of the corolla of composites; the annular 
collar-like process at the junction of the leaf blade and sheath in grasses. 

Linear. Long and narrow, with sides nearly parallel. 

Lobed. Margin cut rather deeply into curved or angular segments. 

Lodicule. A rudimentary organ at the base of the ovarv in grasses. 

Loment. A leguminous fruit (pod) that is constricted between the seeds. 

Mericarp. One of the halves of the fruit of an umbellifcr. 

Mesocarp. The middle coat or layer of a fruit. 

Monadelphous. Having the stamens united by their filaments into one 
body. 

Monocarpous. Having one carpel. 

Monoclinous. Having the androecium (stamens) and the gynoecium 
(pistils) in the same flower. 

Monoecious. Having the androecium (stamens) and the gynoecium (pis- 
tils) in separate flowers but on the same plant. 

Monogynous. Having one carpel or gyncecium. 

Natural classification (key). Classification or key that utilizes natural 
relationships. 

Naturalized. Running wild from cultivation and becoming established. 

Nectary. A nectar-secreting gland; often associated with petals. 

Node. A joint, as in a stem, the point where buds and leaves occur. 

Nomenclature. The naming of plants. 

Nut. A dry, hard-shelled, usually one-seeded, indehiscent fruit; diminu- 
tive form, often used, is nutlet. 

Oblanceolate. Inversely lanceolate. 

Oblique. With the two sides of the blade unequal, especially at the base, 
as in a leaf. 

Oblong. Longer than broad, with nearly parallel sides. 

Obovate. Inversely ovate. 

Obtuse. Tapering abruptly to a point. 

Officinal. Sold in apothecaries; medicinal. 

Oligomerous. Having fewer than the usual number of parts. 

Orbicular. More or less nearly circular. 

Orthotropous. Straight, erect, as an ovule. 

Ovary. Part of a carpel or gyncecium containing the ovules. 

Ovate. Egg-shaped, much broader below the middle. 



392 FLOWERS AND FLOWERING PLANTS 

Ovule. The macrosporangium (megasporaiigium); forerunner of the seed. 

Ovuliferous. Bearing ovules. 

Palea. The upper or inner of the two bracts of the floret in grasses, often 
partly inclosed by the lemma. 

Palet. Older term for palea. 

Palmate. Palm-like; applied to the venation of a simple leaf when the 
principal veins radiate from a common point at the base of the blade; 
same as digitate; also applied to a compound leaf in which the leaflets 
are arranged in this manner. 

Panicle. A compound racemose inflorescence, as in the oat. 

Paniculate. Of the character of a panicle; bearing panicles. 

Papilionaceous. Butterfly-shaped, referring to the corolla of some legumi- 
nous flowers. 

Pappus. The modified bristly or scale-tike calyx of composites 

Parietal. Borne on the sides or wall of a locule, as ovules in the ovary. 

Parted. Margin cut nearly to the midrib, as in a leaf. 

Pedicel. The flower stalk. 

Peduncle. The stalk of an inflorescence. 

Peltate. Shield-shaped. 

Pentamerous. Having five members in a whorl, or 5-merous. 

Pepo. The fruit of a gourd or pumpkin; a sort of berry with a hard 
rind. 

Perennial. Living through more than two years. 

Perfect. Having both andrcecium (stamens) and gymrcium (pistils) in the 
same flower; bisexual. 

Perfoliate. Having the stem apparently passing through the leaf. 

Perianth. The floral envelop; sepals and petals. 

Pericarp. The wall of the ovary, referring especially to a fruit. 

Perigynium. The inflated sac (bract) enclosing the gymvcium or carpellato 
flower in Carex. 

Perigynous. Standing around the gymrcium, borne on the margin of the 
floral axis. 

Perisperm. The, remnant of the iiucellus; often stored with accessory food 
(compare \^th endosperm). 

Petal. One of roe colored inner perianth (corolla) segments. 

Petiole. A leaf stalk (compare with blade). 

Phyllotaxy. Leaf arrangement on a stem. 

Phylogeny. The racial or genetical relationship or development of organ- 
isms. 

Pilose. With soft slender hairs. 

Pinnate. Feather-like; applied to the venation of a simple leaf or leaflet of 
a compound leaf when the principal veins extend from the midrib 
toward the margin and are more or less parallel; also to a compound 
leaf when the leaflets are so arranged. 

Pinnatifid. Cleft or parted in a pinnate manner. 

Pistil. The ovuliferous or seed-bearing organ of a flower; carpel ; gyniccium. ; 
consisting of ovary, style, and stigma. 

Pistillate. Bearing the pistil or pistils only; carpellate. 

Placenta. The tissue within an ovary to which the ovules are attached. 

Placentation. The arrangement or orientation of the placentae. 



GLOSSARY 393 

Plicate. Said of a leaf in which the blade is folded back and forth along the 

main veins like the pleats in an accordion. 

Pollination. The transfer of pollen from the anthers to the stigma. 
Pollinium. The mass of cohering pollen grains of orchids and milkweeds. 
Polygamous. Bearing unisexual and bisexual flowers on the same plant. 
Polypetalous. Having separate petals. 
Polysepalous. Having separate sepals. 
Pome. A fruit, like an apple or pear, in which most of the edible part is the 

enlarged axis of the flower, rather than the ovary. 
Protandrous flower. A flower in which the stamens mature before the 

pistil. 
Protogynous flower. A flower in which the pistils mature before the 

stamens 

Pruinose. Dusted with coarse granular material. 
Puberulent. With very fine down-like hairs. 
Pulverulent. Dusted with fine powder or dust. 
Punctate. Dotted, often with resinous glands. 
Receptacle. The part of the floral axis (pedicel or peduncle) that bears the 

floral organs; the hypanthium of perigynous and epigvnous flowers; also 

used for the common axis of the flowers in the inflorescence of the 

composites. 

Regular flower. Having radial symmetry; actmomorphic. 
Reniform. Kidney-shaped. 
Repand. With a slightly wavy margin. 
Retuse. Rounded or slightly notched. 
Revolute. Said of a leaf in which the two sides of the blade are rolled 

lengthwise over the lower surface toward the midrib. 

Rhizome. An elongated subterranean stem or branch; usually horizontal. 
Rootstock. Same as a rhizome. 
Rosette. A cluster of closely crowded radiating leaves arising from a very 

short stem near the surface of the ground. 
Rostellum. A little beak; a projection from the upper edge of the stigma 

in orchids. 

Rotate. Wheel-shaped, referring to a sympetalous corolja.as in Solatium. 
Sagittate. Arrow-shaped, with the basal lobes directed downward 
Samara. An indehiscent, dry, one- or two-seeded, wmgett fruit as in maples. 
Scabrous. Rough; rough-pubescent. 
Scape. A stout or slender peduncle rising from the ground and bearing one 

or more flowers at the summit. 
Scapose. Of the character of a scape. 
Scarious. Dry, thin, scale- like; membranaceous. 
Seculate. Sickle-shaped, more or less like a curved lanceolate form. 
Sepal. A segment of the calyx. 
Septum. A partition, referring especially to the partitions in a compound 

ovary. 

Sericeous. With silky hairs. 

Serrate. With sharp marginal teeth that point forward. 
Sessile. Without a stalk, as a leaf without a petiole. 
Sheath. The tubular, basal portion of a leaf of a grass or sedge, which 

encircles the culm. 



394 FLOWERS AND FLOWERING PLANTS 

Sheathing. Said of a leaf in which the expanded base of the petiole more or 

less completely invests the stem. 
Sihcle, silique. The fruit (pod) of crucifers. 
Simple. Not branched, referring to sterna; not compound, referring to 

gyncecia; or not compound, referring to leaves. 
Sinuate. With more abruptly wavy margin than repand. 
Sinus. The cleft or indentation between the lobes of a leaf blade. 
Spadix. A succulent axis supporting an inflorescence, as in the aroids. 
Spathe. The leaf-like colored bract investing the inflorescence (spadix) of 

aroids and palms. 
Spatulate. Spoon-shaped, broad and rounded above the middle and 

tapering gradually to a narrow base. 
Spicate. Having the form of a spike. 
Spike. An elongated inflorescence bearing sessile flowers. 
Spikelet. A small spike; the unit of inflorescence of grasses and sedges. 
Spiral. Arranged in a winding series, as leaves or floral organs. 
Squarrose. With minute scales. 
Stamen. The pollen-bearing organ of a flower, consisting of filament and 

anther. 

Staminate. Bearing stamens; consisting of stamens, as a flower. 
Standard. The broad upper petal of many leguminous flowers. 
Sterile. Not productive. Not capable of producing seed, as a neutral 

flower. 
Stigma. That part of the style which is modified tor the reception and 

germination of the pollen. 

Stigmatic. Belonging to or of the nature of the stigma. 
Stipe. A stalk, as of a gyn<rcium or a flower. 
Stipule. A leaf -like appendage of the base of the petiole of leaves; often in 

pairs. 
Stolon. A slender modified stem growing along the surface ot the ground 

and rooting at the nodes. 
Stoloniferous. Bearing stolons. 
Strigose. With rigid hairs or bristles. 
Style. The contracted upper part of a carpel or gyncecium that supports 

the stigma; often considerably elongated, sometimes lacking. 
Superior. Wholly free from the receptacle, referring to the ovary. 
Suture. The line of dehiscence of dry fruits. The line of junction or of 

cleavage of two united organs. 
Syconium. The fleshy fruit of the fig. 

Symmetrical. Regular in shape, size, and number of parts; actmomorphic. 
Sympetalous. Having united petals, or a one-piece corolla; gamopetalous. 
Synandrous. Having the anthers -united. 
Syncarpous* Having united carpels. 

Synergids. The two nuclei, which with the egg constitute the "egg appa- 
ratus" of a flower. 

Synsepalous. Having united sepals; gamosepalous. 
Taproot. A permanent, more or less thickened, often fleshy, primary 

root. 
Tassel. The staminate inflorescence of maize. 



GLOSSARY 395 

Taxonomy. Systematic botany, involving the naming and classification of 

plants. 

Tendril. A slender, leafless, spirally coiling, and sensitive organ of climb- 
ing plants. 

Testa. The outer, usually hard, coat of a seed. 
Torus. The receptacle of a flower. 

Trifoliate. Three-leaved, sometimes confused with following. 
Trifoliolate. Having three leaflets, as in a compound leaf. 
Trimorphic. Existing in three forms. 
Truncate. Seemingly cut off square or nearly so. 
Tuber. A much thickened, usually short, subterranean stem, as in the 

Irish potato. 

Tuberous. Of the nature of a tuber. 

Twiner. A plant that climbs by means of spirally coiling stems. 
Umbel. An umbrella-shaped inflorescence, m which the pedicels radiate; 

from a common point at the summit of the peduncle. 
Umbellate. Of the form of an umbel. 

Umbellet. A secondary umbel; one of a set of smaller umbels of a com- 
pound umblc. 

Umbelliferous. Bearing umbels. 
Unilocular. Composed of one locule, as in an ovary. 
Valvate. Dehiscing by valves or equal sections. Jn aestivation, when the 

segments of the perianth are so placed that their edges touch; not 

overlapping. 

Valve. A section of a dry, dehiscent fruit (capsule) separated in dehiscencc. 
Venation. Nervation. The arrangement of the nerves or veins of a loaf. 
Vernation. The arrangement or mode of folding of leaves in the bud. 
Verrucose. With minute warts or blunt projections 
Versatile. Attached by the middle so as to swing freely, as an anther on 

the filament. 

Verticillate. A whorled cluster of leaves or flowers 
Villous. With long shaggy hairs 
Whorl. A circle or ring of organs inserted around an axis, as the organs of 

a flower or leaves on a stem; a cycle. Whorled. 
Wing. An outgrowth from the side of an organ; the lateral petals in the 

flowers of many legumes. 
Winter annual. A plant that grows from seed in the late summer or autumn, 

lives through the winter, matures and dies the following summer, as 

winter wheat. 
Xenogamy. Pollination between flowers of totally separate individual 

plants. 
Zygomorphic. Said of a flower having bilateral symmetry, such as that ol a 

mint or snapdragon. 



INDEX 



Pages on which illustrations occur arc indicated by bold-faced type; 
names of orders, families, genera, and species are in italics, as are references 
to certain historic publications. 



Abutilon, 32 
Abyssinian banana, 314 
Acacia, 235 

senegat, 235 
Acanthaceae, 228 
Acanthus, 228, 229 

molhs, 229 

Acanthus family, 229 
Accessory fruits, 49, 51, 52, 54 

organs, 4 
Acer, 46, 64, 117, 142, 101, 261, 262 

negundo, 4, 161, 262 

platanoides, 262 

pseudoplatanus, 262 

saccharinum, 261, 262 

saccharum, 161, 261, 262 
Accraceae, 261, 262 
Aehene, 43, 45, 51, 54 
Achillea mil le folium, 283 

ptarmica, 283 
Acnida, 207 

Acokanthera schimperi, 220 
Aconite, floral diagram of, 89, 90 
Aconitum, 16, 44, 89, 90, 169, 174, 

175 

Acorn, 43, 46, 266 
Acorus, inflorescence of, 107 
Actinomorphic flowers, 15, 83, 153, 

159 

Actinomorphy, 15, 83, 153, 159 
Adhesives, 367 
Adonis, 43 

achenes of, 43 
Adventitious buds, 115, 120 
Adventitious roots, 117 
Aerial roots, 115, 118, 121 



Aerial stems, 121 

AesculuSj inflorescence of, 111, 260 

Aesculiut glabra, 260 

hippocastanum, 260 
Aethusa, 269 
African marigold, 281 
Agave, 311 
Agave americana, 311 

sisalana, 311 
Ageratum, 282 

houstonianum, 282 
Age, of roots, 117, 118 

of stems, 120, 121 
Ages, dark, 319 

middle, 319 

Aggregate fruits, 49, 51, 52, 54 
Agrimonia, inflorescence of, 105 
Agrimony, inflorescence of, 105 
Agropi/ron, 68 

rhizome of, 68 
Agroslemma githago, 204 
Agrostideae, 303, 306, 307 
Agrostis alba, flowers of, 307 

inflorescence of, 307 

spikclet of, 307 
Aids, in drying specimens, 366 

to migration, 63, 72 
Ailanthus, 7, 46, 64 
Ajuga, 16 

Albuminous seeds, 60 
Alchemilla, 27 
Alder, 30, 266 
Alfalfa, 222, 237 
Algaroba, 235 
Alisma, 16, 43, 287 

floral diagram of, 89, 287 

floral formula of, 101, 287 

plantago aquatica, 287 



397 



398 



FLOWERS AND FLOWERING PLANTS 



Alisma, subcordatum, 287 
Alismaceae, 286, 287 

floral diagram of, 89, 287 

floral formula of, 101, 287 
Alismales, 286, 291 
Alligator pear, 172 
Attium, 4, 141, 292 

bulb of, 70 

cepa, 141 

flower of, 76 

inflorescence of, 108 
Allogamy, 28 
Allspice, 244 

Almond, 12, 13, 21, 233, 234 
Alnus, 30, 266 
Aloe, 292, 311 
Alsike clover, 109 
Alternate leaves, 127 
Alternifoliae, 348, 350 
Althaea, 79, 180, 181 

rosea, 181 
Alyssurn, 202 
Alyssum, 202 
Amaranth, family, 203, 206 

flowers of, 22 

fruit of, 44 

Amaranthaceae, 203, 206 
Amaranthus, 22, 44, 207 
Amaryllidaceae, 310, 311 
Amaryllis, family, 310, 311 

floral diagram of, 311 

floral formula of, 102, 311 
Amaryllis belladonna, 311 
Ambrosia, 279, 280, 282 

artemisiae folia, 280 

trijida, 280 

Ambrosieae, 279, 280, 282 
Ame,ntiferae, 30, 154, 155, 345 
American ash, 219 

aloe, 311 

beech, 265 

elm, 183, 184 

linden, 181 

papaw, 170, 199 

persimmon, 215, 216 

spikenard, 267 

sycamore, 241 

Ammophila breviligulata, 307 
Amygdalus, 12, 13, 233, 234 



Anacardiaceae, 262 
Anacardium occidental, 262 
Analytical keys, 160-165 

bracket, 162-164 

dichotomous, 163 

indented, 162-164 
Ananas sativa, 313, 314 
Anatomy of the flower, 10, 1 1-25 
Anatropous ovule, 39, 39 
Ancestors of maize, 308 
Ancients, work of, 318 
Andrena crataegi, pollen load of, 34 
Androecium, 16, 17, 122, 123 
Andropogon furcatus, 308 

scoparius, 304, 308 
Andropogoneae, 304, 308 
Androsace, 212 
Anemone, 9, 175 

acheno of, 9 

flower of, 75, 86, 175 
Anemophilous species, 30, 31, 352 
Angelica, 269 
Angelica, Chinese, 267 
Angiosperrns, 1, 27 

distribution of, 1 

habits of, 1 

mode of life of, 1 

new species of, 1 

number of, 1 

value of, 1 

Angraecum sesqmpedale, 35 
Animals, as agents of migration, 64, 
65 

pollination by, 32 
Anise, 269 
Annuals, 117, 120 
Anona, flowers of, 51, 62, 170 

floral diagram of, 170 

floral formula of, 170 

fruit of, 51, 62 
Anona muricata, 170 

squarnoxa, 170 

utriculata, 170 
Anonaceae, 170, 199 
Antennaria, 27 
Anthemideae, 279, 283 
Anther, 3, 4, 17 
Anthopogon elegans, 218 
Anthoxanthum odoratum, 306 



INDEX 



399 



Antipodals, 40, 41 
Antirrhinum, 16, 33, 226 

floral diagram of, 92, 226 

flower of, 33, 77, 226 
Antirrhinum ma jus, 226 
Apetalae, 154, 155, 345 
Apetalous species, relationships of, 

152, 155, 345 
Apetaly, 152, 155 
Apios, tuber of, 69 
A pis melhjica, pollen load of, 34 
Apium, inflorescence of, 107 
Apium graveolens, 269 
Apocarpous flowers, 79, 153 
Apocarpy, 79, 153 
Apocynaceae, 219, 219 
Aponogeton fenestralis, 30 
Apopetalae, 155, 335 
Apple, flower of, 76, 115, 233, 233 

fruit of, 76, 233 
Apricot, fruit of, 50, 233, 234 
Aquatic species, 30 
Aquifoliaceae, 257, 268 
Aqmlegia, 36, 78, 174, 175 

floral diagram of, 89 
Aquilegia coerulea, 175 
Araceae, 102, 107, 296, 297 
Arachis hypogaea, 237 
Aragallus tambertii, 237 
Amies, 296, 297, 298 
Aralia, 266, 267 
Araha chinensis, 267 

nudicaulis, 267 

racemosa, 267 

spinosa, 267 
Araliaceae, 266, 267 
Araujia, 220 
Arbores, 323 
Arbutus, 215 
Arctostaphylos, 17, 214 
Ardotideae, 279, 280 
Aril, 60 
Arisaema, 32, 296, 297 

bracts of, 112 

corm of, 70 

Arisaema triphyltum, 296, 297 
Aristotle, 318 
Aroids, 295, 296, 297 
Arrow poisons, 219 



Arrowgrass family, 287 
Arrowheads, 7, 23, 101, 286, 287 

achene of, 43, 45 
Artedia, 46, 48 
Artemisia frigida, 283 

tridentata, 283 
Artichoke, globe, 281 

Jerusalem, 69 
Artocarpus conimums, 184 
Arum, inflorescence of, 296 
Arum family, 296, 297 

order, 295 
Arum itahcum, 296 
Asclepiadaceae, 220, 220 
Asclepias, floral diagram of, 90, 220 

inflorescence of, 108, 220 

seed of, 66, 63 
Asclepias incarnata, 220 

syriaca, 220 

taberosa, 220, 220 
Ash, 7, 46, 219 

American, 219 

European, 219 
Asiatic plane, 241 
Asimimi tnloba, 170, 199 
Asparagus, 82, 91, 292, 292 
Asparagus asparagoides, 122, 292 

plumosus, 292 
Asparagus broccoli, 202 
Aspen, 7, 63 
Aspidistra, 32 

Aster, 24, 232, 270, 276, 279, 282 
Aster family, 276-283 
Aster novae- angliae, 282 

now-belgii, 276, 282 
Aster order, 275-283 
Asterales, 275-283 
Astereae, 276, 279, 282 
Astilbe, 238 
Astilbe japonica, 238 
Atropa, 49, 224 
Atropa belladonna, 224 
Attaching specimens, 367 
Auricles, 131, 131 
Autogamy, 28 
Avena, 48 

floral diagram of, 301 

inflorescence of, 110, 305 

panicle of, 306 



400 



FLOWERS AND FLOWERING PLANTS 



Avena fatua, spikelet of, 306 

saliva, floret of, 305, 306 
Aveneae, 303, 306 
Avens, achenes of, 66 
Averrhoa carambola, 189 
Avocado, 172 
Awnless brome, 306 
Axillary buds, 110-121, 126 
Axis of flower, 12 
Azalea, fruit of, 47 

B 

Baby's breath, seed of, 56, 204 
Balloon flower, 275 
Balloon vine, 261 
Balsam, apple, 252 

family, 191, 192 

floral diagram of, 92, 192 

flower of, 33, 192 
Balsaminaceae, 191, 192 
Bamboo grasses, 303-305 
Bambuseae, 303, 304 
Banana, 43 

rhizome of, 68, 314 

tree, 313, 314 
Banana family, 313, 314 
Banner, 15, 236 
Banyan, 185 
Barberry, flowers of, 173 

fruit of, 49 

stamen of, 17, 80 
Barberry family, 172, 173 
Bark, 124 

Barley, wild, spikelets of, 302 
Barley grasses, 303, 305 
Basswood, 181, 181 
Bats, as pollinating agents, 32 
Bauhin, Caspar, 321 
Bauhin's Phytopinax, 321 
Bay tree, 172 
Beach grass, 307 
Beachwheat, 208 
Bean, flower of, 15, 16, 236 

pollination of, 36 
Bean family, 15, 36, 235, 236 
Bearberry, flower of, 214 

stamen of, 17 
Beardtongue, 226 



Beech, 30, 46, 265 

American, 265 

European, 265 
Beefsteak geranium, 250 
Beet root, 206 
Beets, 206 

seed of, 66 
Begonia, 249, 260 
Begonia family, 249, 250 
Begonia rex, 250 

semperjlorens, 250 
Begomaccae, 249, 260 
Belladonna, 224 
Belladonna lily, 311 
Belhs perenmx, 282 
Bennettitales, 150 
Bentham, George, 335 
Bentham and Hooker, system of 

classification of, 335-338 
Benzoin acstwale, 172 
Berberidaceae, 80, 172, 173 
Berberis, 17, 49, 173 

thunbergii, 173 

vulgarisj 173 
Bergamot oil, 191 
Bermuda grass, 305 
Berry, 49, 50, 52, 54 
Bertholettia, 58 
Bossey, C. E., 329, 346, 348 

dicta of, 151-159 

outline of system of, 348-361 

system of classification of, 348-353 
Beta, 66 

Beta vulgaris, 206 
Betel leaves, 177 
Betula, 152 
Betula alba, 266 

papyri/era, 266 
Betulaceae, 265, 266 
Biennials, 117, 118, 120 
Bignoma, 32, 226 

seed of, 63 

Bignoma family, 226, 227 
Bignoniaceae, 226, 227 
Bilabiate corolla, 16, 231 
Bindweed, pollen of, 18, 222, 222 

rhizome of, 68 

Binomial nomenclature, 140, 146, 
147, 321 



INDEX 



401 



Binomials, formation and use of, 

140-142, 146, 147 
Birch, flowers of, 30, 266 

inflorescence of, 106, 107 

paper, 265, 266 

white, 266 

Bird-of-paradise plant, 315 
Birds as pollinating agents, 32 
Birdseed, 306 
Bitter cassava, 194 
Bitterroot, 205 
Bittersweet, 8, 23, 254, 255 

family, 254, 255 

order, 254 
Black cherry, bark of, 124 

currant, 239 

haw, 110, 272 

mustard, 202 

pepper, 177 

walnut, 264 
Blackberry, 12, 50 

fruit of, 51, 52 
Bladdernut, fruit of, 64 
Bladderwort, floral diagram ot, 92 

family, 229 
Bleeding heart, 200 
Bhphanglottis cihata, 85, 317 
Bloodroot, 200 
Blue bottle, 281 

cohosh, 174 

columbine, 175 

eyes, 223 

gentian, 218 

grama, 116, 304, 305 

grass, 110, 302, 305 

gum, 244 
Bluebell, 13, 81, 93, 100, 104, 106, 

270, 274, 275 
Bluebell family, 274, 275 

order, 274 

Blueberry, 4, 50, 214, 215 
Bluestcm, 304, 308 
Bock, 319 

Boehmeria nivea, 186 
Bombus juxtus, pollen load, 34 
Boneset, 279, 282 
Books of reference, 370-383 

on cultivated plants, 379-380 

on grasses, 380-381 



Books of reference, on trees, 376- 

378 

Borage family, 98, 224, 225, 230 
Borages, 224-225 
Boraginaceae, 98, 224, 225, 230 
Boston ivy, 256 
Bougainvillea, bracts, 112 
Bouncing bet, 205 

seed of, 56 
Boiiteloua, 304, 305 
Bouieloua gramUs, spikelet of, 304, 

305 

Boxclder, 4, 23, 161, 262 
Boxwood, inflorescence of, 1 10 
Bracket keys, 162, 163, 164 
Bracteoles, 136 
Bracts, 111, 112, 136 
Brasenia, 176 
Brassica, 9, 202 
Brassica napobrassica, 202 

nigra, 202 

oleracea, 202 

oleracea, var. botrytis, 202 
var. caulorapa, 202 
gemmifera, 202 
italica, 202 

rapa, 202 
Braun, A., 340 
Brazil nut, 46 

seed of, 58 
Breadfruit, 184-185 
Bridal wreath, 4 
Broccoli, 202 

Brome grass, 64, 302, 306 
BromeMaceae, 212, 313 
Bromus inermis, 306 

necalinus, 302 

teclorum, 306 
Brongniart, A., 335, 340 
Broom com sorghum, 308 
Broornrape, 227. 228 
Broussonetia papi/rifera, 185 
Brown, Robert, 333 
Brunfels, 319 
Brussels sprouts, 202 
Bryophyllum, 120 
Buckbrush, 272 
Buckeye, 260 



402 



FLOWERS AND FLOWERING PLANT* 



Buckthorn, 60, 256, 267 

nectary of, 36 
Buckthorn family, 256, 267 
Buckwheat, 22, 207, 208 
Buckwheat family, 207, 208 
Bud scales, 119, 120, 121 
Buds, 119-120 

adventitious, 1 1 5 

axillary, 119, 120, 121 

lateral, 119, 120, 121 

mixed, 120 

naked, 120 

supernumerary, 120 

terminal, 119, 120, 121 

winter, 119 
Bud-scale sears, 121 
Buffalo grass, 305 

runners of, 71 
Bugle, flower, 16 
Bulbilis dactyloides, 305 
Bulbs, 70, 136 
Bulrush, 300 
Bunchberry, 268 
Bundle scars, 120, 121 
Bur cucumber, 123 
Bur reed, 288, 289 
Burdock, 279 
Burmanniaceae, 315 
Burning bush, 255 
Bursa, 79, 91 
Buttercup, 22, 44, 45 

achene of, 9, 11, 43 

floral diagram of, 89 

floral formula of, 96, 174 

flower of, 74, 75, 174, 232 
Buttercup family, 174, 174, 175 

order, 168-178 
Butterfly weed, 220, 220 
Butternut, 120, 264 

fruit of, 46 

Buttonball tree, 109, 241, 242 
Buttonbush, 109 

inflorescence of, 108, 272 
Buxus, 110 

C 

Cabbage, 202 
Cabbage palm, 299 



Cabomba, 176 
Cabombaceae, 176 
Cacao, 182, 182 
Cactaceae, 100, 101, 262 
Cactales, 243, 262, 254 

relationships of, 243 
Cactus, 100, 101, 248, 262, 254 

floral diagram of, 89, 90, 262 

floral formula of, 100, 252 
Caesalpiniaceae, 234, 236 
Calamagrostis canadensis, spikelet of, 

307 

Calamus, 299 
Calandrinia, 17 
Calceolaria, 226 
Calendula, 278, 279 

officinahs, 24, 281 
Calendulene, 279, 281 
California blue eyes, 223 
California poppy, 200 
Calla lily, 32, 297 

bracts of, 112 
Callirrhoe, 180 
Callilnche, 29 
Calluna, 215 
Calochortus, 292 
Caltha, 75, 175 

palustris, 174 
Calyx, 3, 4, 14 

synsepalous calyx, 80 
Camellia, 195, 196 
Cameron us, 323 
Campanula, 13, 81, 93, 104, 106, 274 

media, 275 

rotumifolia, 274, 275 
Campanulaceae, 100, 274 
Campanula's, 274 
Carnperdown elm, 184 
Camphor tree, 172 
Camphora officinarum, 172 
Campylotropous ovule, 39 
Canada thistle, rhizome of, 68 
Canary grass, 303, 306 
Candolle, A. P. de, 331-333 

influence of, 331 

system of classification of, 331- 
333, 336, 346 

Thtorie tttmentaire de botaniqae, 
332, 333 



INDEX 



403 



Candolle, Alphonse de, 331-333, 346 
Candytuft, 202 
Cane, 308 
Cannabmaceae, 185 
Cannabis, 185 

experiments with, 323 
Cannaceae, 315 
Cantaloupe, 251 
Caoutchouc, 194 
Capacity to migrate, 62 
Cape jasmine, 271 
Caper, 200, 201 
Caper family, 200, 201 
Capparidaceae, 200, 201 
Cappnris spinosa, 201 
Caprifohaceae, 100, 271, 272 
Capnola dactyl on, 305 
Capsicum, 178 

frutescens, 224 
Capsule, 44, 47, 54 
Carambola, 189 
Caraway, 48 
Carbohydrates, 59 
Cardboard for press, 362-364 
Cardiospermum hahcacabuw , 2(51 
Carduus, 87 
Carex, 300, 300 
Canca papaya, 198 
Caricaceae, \ 98 
Canssa carandas, 219 
Carnegiea gigantea, 17, 20, 21 
Carpels, 6, 20 

union of, 6, 20 
Carrion flower, 34 
Carrot, 13, 47, 63, 77, 79, 115, 269 
Carum, 48, 142 

cam, 269 

Caryophyilaceae, 163, 204, 207 
Caryopsis, 47, 48, 54, 299, 303 
Cascara sagrada, 257 
Cashew, 262 
Cashew family, 262 
Cassava, 194 
Cassia, 236 
Castanea dentata, 47, 265 

saliva, 265 
Castor bean, 66 
Castor oil, 193 



Castor oil plant, 193 

experiments with, 323 
Catalpa seed, 63 
Catatpa speciosa, 227, 227 
Catasetum, 85 
Catchfly, 204 
Catkin, 106 

of birch, 107, 266 

of cotton wood, 209, 209 

of willow, 209, 209 
Catnip, 84 
Cattail, 7, 17, 23, 102, 289 

rhizome of, 68, 289 
Cattail family, 289, 289 
Cattle ya labiata, 317 
Cauliflower, 202 
Caulophyllum thalictroides, 174 
Ceanothus, 257 
Celastraccae, 254, 265 
Celastralcs, 254 

relationships of, 254 
Cclastrus scandcns, 255 
Celery, 269 
Cclosia cristatu, 207 
Celtic 1<S4 

Cenchrun pauwjlorus, 307 
Centauren, 43, 56, 81, 278, 281 

cyanus, 281 

Centrifugal, order of flowering, 109 
Centripetal, order of flowering, 105 
Century plant, 311 
Cephalanth us, flower of, 272 

inflorescence of, 108 
Ceratonia siliqua, 235 
Ceratophyllum, 29 
Ccrcis canadensis, 235 
Ccrcocarpus, flower of, 76 
C'ereals, 30 

Cere us tnangularis, 253 
Cesalpino, 320 
Chaetochloa, 307 
Chaetochloa, 307 

italica, 307 

Chamaerops humilis, 298 
Changing the press, 365 
Chaparral, 257 
Chard, 206 

Cheiranthus cheiri, 202 
Cheirinia, 44 



404 



FLOWERS AND FLOWERING PLANTS 



Chenopodiaceae, 102, 104, 106, 203, 

205, 206 
Chenopodium, 66, 206 

hybridum, 206 
Cherry, 9, 50, 233, 234 

ground, 224 
Chestnut, 7, 23, 30, 46, 47, 205 

American, 265 

European, 265 
Chick weed, 65 
Chicory, 279, 280, 281 
Chinese silk plant, 186 

angelica, 267 

date, 257 

htchi, 261 

palm, 298 

primrose, 212 

wisteria, 237 
Chlondeae, 303, 305 
Chlorophyll, 2 
Chocolate, 182 

plant, 182 

seed, 68 

Christian era, 318 
Christmas cactus, 253 
Chrysanthemum, 24, 283 
Chrysanthemum, 24, 283 

balsamita, 283 

cocdneum, 283 

frutescens, 283 

indicum, 283 

sinense, 283 
Chchoneae, 279, 281 
Cichorium, 281 

endivia, 281 

intybus, 280, 281 
Cigar flower, 248 
Cimicifuga, 175 
Cinchona, 271 

officinalis, 271 
Cineraria, 281 

Cinnamomum zeylanicum, 172 
Cinnamon, 172 
Circaea, 18 

Circassian walnut, 264 
Cirsium arvense, 281 
Cissus, 256 
Citrocarp, 51 
Citron, 191, 252 



Citrullus vulgaris, 251, 252 
Citrus, 52,90, 190, 191 

aurantium, 93, 191 

bergamia, 191 

grandis, 191 

limonia, 191 

medica, 191 

nolnlis, 191 

sinensis, 191 

trifoliata, 191 
Cladophylls, 121, 122 
Classes, concept of, 142, 143 
Claytonia, 142 

Clematis, 14, 24, 43, 64, 66, 75, 174 
Clematis, 14, 24, 43, 61, 66, 174 
Cleonif serrnlata, 201 

spinosa, 201 

Climbing plants, 122, 123 
Clinandruiin in orchids, 317 
Cloth-of-gold crocus, 313 
Clove, 244 
Clove pink, 204 
Clover, 7, 236, 237 

red, 237 

white, 237 
Club xv heat, 305 
Clusms, 319 
Clusters of flowers, 104-111 

cymose, 109-111 

racemose, 105-109 
Coats, seed, 60 
Cobaea, 18 
Cochineal, 253 
Cochineal cactus, 253 
Cochlearia, 7 
Cockelbur, 280 
Cockscomb, 207 
Cocoa, 182 
Coconut, 50, 65, 298 
Coeos nuafera, 298 
Codiacum, 193 

Coffca arabica, 13, 49, 81, 271 
Coffee, 13, 49,81, 87, 271 

substitute for, 281 
Coffee tree, Kentucky, seed of, 58 
Cohosh, 174 
Coix lachryma-jobi, 308 
Cola acuminata, 183 
Cola tree, 183 



INDEX 



405 



Colchicum, 9 

Collecting, equipment for, 354-369 
Collecting specimens, 354-369 
Colocasia antiquorum, 141 

esculenta, 297 
tuber of, 69 
Columbine, 89, 174, 175 

nectary of, 35, 35 
Column (in orchids), 82, 317 
Commehna, 293 
CommeMnaceae, 292, 293 
Common barberry, 173 
Common groups of plants, 140-147 
Common names of plants, 117 
Complete flowers, 3, 6, 14-25 
Composite, 108, 109, 111, 269, 275, 

276, 277, 278, 279, 280, 282, 283 
Composites, 14, 22, 24, 64, 111, 275, 

277, 278, 280, 282 
Compound inflorescence, 110 
Compound leaves, 128, 129 
Concord grape, 256 
Conoflower, 280 

Conium, 269 

maculatum, 269 

Containers for specimens, 355, 365 
Conoallana, 14, 91, 292 
Corivolvulaceae, 222, 222 
Convolvulus, 18, 222 

arvcnsis, 222 

septum, 141, 222 
Copaifcra yubiflora, 235 
Coral (orrfnza, 125 
Cordate leaf, 131, 131 
Corms, 136 

of Arisaema, 70 

of Crocus, 70 

of Cyclamen, 70 
Corn, 304, 308 

inbreeding of, 28 
Cornaceae, 267, 268 
Corncockle, 204 
Cornflower, 43, 66, 81, 281 
Cornus, 50, 268 

florida, 24, 112, 268 

nuttallii, 112 
Corolla, 3, 4, 14 

bilabiate, 16, 17 

papilionaceous, 7, 15, 16, 84, 236 



Corolla, sympetalous, 14, 16, 17, 80 
Corydalis, 200 
Corylus, 22, 30 
Corymb, 107 
Cotton, 180 

mercerized, 180 
Cotyledons, 58 

Coulter's New Manual of Botany of 
the Central Rocky Mountains, 163 
Crabgrass, 307 
Cranberry, 215 

fruit of, 50 

Crass ulaceae, 242, 242 
Cress, 202 

Crtnum amcricanurn, 311 
Crocus, 142, 

corin of, 70 
Crocus sativux, 312 

susianus, 313 
Croton, 193 

"Crown" (in Narcissus), 310 
Crown-of-thorn plant, 193 
Cruciferae, 48, 91, 201, 202 
Crucifers, 201, 202 
Cubeb, 177 
Cucumber, 23, 93, 261, 252 

family, 250, 251 

squirting, 66 
Cucumis, 93, 251 

melo, 261 

satwus, 261, 252 
Cacurbita, 18, 250 

pepo, 260 

Cucurbitaccae, 250, 251, 252 
Cultivated plants, books on, 379-380 
Cuphea platycentra, 248 
Cuprcssus macrocarpa, 140 
Currant, 50, 239, 240 

fruit of, 9, 240 

stolon of, 71 
Cuscuta, 222 

Custard apple, 51, 52, 170 
Cy at hi urn, 193 
Cyclamen, 70, 212 

corm, 70 
Cycle, sexual, 41 

Cyclic flowers, 73, 74, 75, 77, 152 
Cycloloma, 67 
Cyclopedias and manuals, 371-373 



406 



FLOWERS AND FLOWERING PLANTS 



Cyme, 109 

Cymose inflorescence, 109 
Cynara scolymus, 281 
Cynarieae, 279, 281 
Cyperaceae, 30, 299, 300 
Cyperus, 300 

alter mfolius, 300 

papyrus, 300 
Cypress vine, 222 
Cypripedium, 33, 316, 317 

D 

Dactylis glomerata, 305 

Daemonorops, 298 

Daggerweed, 105 

Dahlia, 278, 280 

Dahlia, 278, 280 

Daisy, 24 

Dandelion, 18, 24, 27, 31, 44, 64, 87, 

109, 278 

Darwin, Charles, 27, 33 
Dasheen, 107 

Date, seed of, 68, 298, 298 
Datepalm, 23, 298, 298 
Datura, 14, 224 

stramonium, 224 
Daucus, 13, 47, 63, 79, 79, 108, 269 

carota, 269 
Day .lily, 293 

Definition of species, 140, 145 
Dehiscent fruits, 44, 45, 47, 48, 54 
Delayed germination, 61 
Delicious monster, 296, 297 
Delphinium, 33, 82, 169, 175 
Dendrocalamus, 304 
Dent corn, 308 

Derived flowers, 105, 151-154, 284 
Determinate growth, 109 
Deutzia, 239 

Development of the embryo, 40 
Dewberry, 51, 52 
Dialypetalae, 335 
Dianthus, 18, 204, 204 

caryophyllus, 204 
Dicentra spectabilis, 200 
Dichogamous species, 28 
Dichogamy, 28 
Dichotomous keys, 163 



Diclinism, 23, 28 
Dicliny, 23, 28 
Dicotyledons, 156, 157 

features of, 167, 168 

floral pattern of, 168 

growth of, 167-168 

length of life of, 167 

orders and families of, 167-283 

relation to monocotyledons, 156- 
158 

vegetative nature of, 167, 168 
Diervilla, 77 

Diggers for the collector, 367 
Digitalis purpurea, 226 
Digtiaria, 307 
Digitate leaf, 129 
Dill, 108 

Dimorphism, 27, 28 
Dioecious species, 23, 28, 154 
Dionaea, 136 
DioscorcaceaCj 315 
Dioscondes, 318 
Diospyios ebcnurn, 216 

kaki, 216 

virginiana, 215, 216 
Dipsacaceae, 273 
dipsacus fullonum, 43, 81, 273 
Dipterocat pus, winged calvx, 46 
Diptetonidj 261 
Disk flowers, 1 11 
Dissecting microscopes, 369, 360 
Diuris, nectary of, 85 
Division of labor, 6 
Dock, sour, 207 
Dodecatheon, 212 
Dogbane, 219 
Dogbane family, 219-220 
Dogwood, 24, 50, 112, 268 
Dogwood family, 267, 268 
Dracaena, 291 

Driers for plant press, 362, 363 
Drosera, 19, 136 
Drupaceae, 233 
Drupe, 9, 49, 60, 54, 234 
Drupelets, 49, 52 
Drying sheets, 362, 363 
Duckweeds, 297 
Dura sorghum, 308 
Duration of roots, 117 



INDEX 



407 



E 



Piaster lily, 292 
Ebenaceae, 215, 216 
Ebenales, 215 
Ebony, 215, 216 
Ebony family, 215, 216 
Ebony order, 235 
Ecballium, 66 
Kcheveria secunda, 242 
Ecluse, de 1', 319 
Edelweiss, 283 
Edges of leaves, 133-135 

cleft, 133 

eremite, 133, 134 

dentate, 133, 134 

divided, 133, 135 

entire, 133, 134 

lobed, 133, 135 

parted, 133, 136 

repand, 133, 134 

serrate, 133, 134 

serrulate, 133, 134 

sinuate, 133, 134 
Egg apparatus, 40, 40, 41 
Eggplant, 223 
Eggs, 5, 8, 27, 39, 40, 41 
Eichler, 338 

system of classification of, 338- 

339 

Eichornia crassipes, 294 
Elaeagnaceae, 258, 259 
Elaeagnus, 60, 56, 269 
Elder, 110, 272 
Elephant ear, 69, 297 
Elliptical leaf, 130, 130 
Elm, American, 22, 30, 46, 183, 184 

camperdown, 184 

English, 184 

red, 183, 184 

slippery, 183, 184 
Elm family, 183, 184 
Elodea canadensis, 30, 310 
Elymus, 141 

Embryo, development, 40, 41, 42 
Embryo sac, 39, 40, 41 
Emmenanthe penduliflora, 223 
Endive, 281 



Endlicher, 334 

system of classification of, 334 
Endocarp, 50, 60 
Endosperm, 60 
Endosperm nucleus, 40, 41 
Engter, Adolph, 340 

Die Naturlichen Pjlanzenfamihcn, 
340 

Syllabus der Pflanzenfatmhen, 340 

system of classification of, 341-345 
English daisy, 282 

elm, 184 

holly, 258 

ivy, 267 

walnut, 264 

Entomophilous flowers, 16, 32, 33 
Epidendrum vitellinum, 317 
Epigaea, 215 
Epigynae, 286 
Epigynous flowers, 12, 13, 77, 79, 81, 

86, 99, 153 

Epigynous monocotyledons, 286 
Epigyny, 12, 13, 77, 79, 81, 86, 99, 

153 
Epilobium, 247 

angasti folium, 248 
Epipactis, 84, 316 
Epipctalous stamens, 82, 100 
Equatorial nucleus, 40, 41 
Equipment for collecting, 354-367 
Erianthus ravennae, 308 
Erica, 214, 214 
Ericaceae, 214, 214 
Ericales, 214 
Eriocaulon, 295, 295 

septangulare, 296 
Eriocaulonaceae, 295, 295 
Eritrichium argenteum, 225 
Erysimum, 4, 90, 202 
Erythronium, 79 
Escallonia, 43 

Eschscholtzia californica, 200 
Essential organs, 4, 23 
Establishment of plants, 62 
Eucalyptus, 244 

globulus, 244 

rostrata, 244 

Euchlaena mexicana, 308 
Eugenia aromatica, 248, 248 



408 



FLOWERS AND FLOWERING PLANTS 



Eulalia, 308 
Euonymus, 255 

atropurpureus, 255 

europaeus, 265 

japonicus, 255 

verrucas us, 255 
Eupatorieae, 279, 282 
Eupatorium, 282 

purpureum, 282 

urticaefolium, 282 
Euphorbia, 193, 193 

jacquinaeflora, 193 

marginata, 112, 193 

pulcherrima, 112, 193 

splendcns, 193 

Euphorbiaceae, 192-193, 323 
European ash, 219 

beech, 265 

linden, 181 

sycamore, 241 

systems of classification, 319-345 
Eustoma, 218 

Evening primrose, 1 3, 246, 247 
Evening primrose family, 246, 247 
Everlastings, 279, 282 
Evolution of flowering plants, 1, 

149-159 

Exalbummous seeds, 60 
Examples of floral formulae, 95-102, 

159 

Exine, 18, 18 

Experiments on sex in flowers, 323 
Explosive fruits, 66, 66 

F 

Fagaceae, 264, 264, 265 
Fagopyron, 207 
Fagus, 30, 265 

grandiflora, 265 

sylvatica, 265 
Families, monographs of, 331 

concept of, 142-145 
Fanpalm, 298 
Farina, 194 
Fascicle, 110 
Fascicled roots, 117 
Fats, 59 



Feather grass, 308 

Female sex cells, 5, 26, 40, 41 

Fennel, 269 

Fertilization, 4, 8, 27, 40, 41 

secondary effects, 42 
Fescue grasses, 303, 305, 306 
Festuca, 306 

elatior, 306 

octo flora, 306 
Fesluceae, 303, 305-306 
Fibrous roots, 116, 116 
Ficus, 52, 185 

benghalensis, 185 

carica, 185 

elastica, 185 

sycomorus, 242 
Filament of stamen, 3, 4, 5, 17, 17, 

25 

Filbert, 266 

Fillers for press, 362-366 
Fire weed, 105, 248 
Flax, 76, 86, 93, 189, 190, 222 

culture of, 190 
Flax family, 189, 190 
Fleshy roots, 116 
Fleur-de-lis, 312 
Flint corn, 308 
Floral bracts, 11, 24, 112 
Floral design, 73-88 
Floral diagrams, 88-94 
Floral envelope, 4, 6, 14, 25, 86, 125 
Floral formulae, 93-103 
Floras, 165, 371-383 
Florets, of grasses, 301, 302 
Florida moss, 313 
Plower clusters, 104-110 
Flowering dogwood, 24, 268, 268 
Flowering plants, origin of, 4, 150, 

151, 155-157 

Flower-like structures, 23 
Foeniculum, 269 
Folders for press, 362-364 
Follicle, 44, 49 
Foods, in fruits, 44 

in seeds, 41, 44, 59 
Forget-me-not, 225 
Forget-me-not family, 224, 225 
Form of plant names, 140-147 



INDEX 



409 



Formulae, for apctalous types, 102 
lily type, 101 
monocotyledons, 101 
to show epipetalous stamens, 

100 

for flowers, 93-103 
contrasts shown, 97 
examples of, 95-102 
extension of, 96-103 
method of, 93-103 
structure of, 94-102 
symbols used, 94, 159 
floral " compounds," 94 
floral "elements," 94 
weaknesses in, 95 

Foundation of modern botany, 322 
Four-o'clock, 208, 208, 209 
Four-o'clock family, 208, 208 
Foxglove, 92, 226 
Fragaria, 49, 75, 234, 233 

runners, 71 
Fraxinus, 219 
americana, 219 
excelsior, 219 
Fringed gentian, 217, 218 
Fritillana, 91, 292 
Fntillary, 292 
Frogsbit, 310 
Fruit balls of potato, 57 
Fruits, 6, 8, 9, 41, 42, 43, 44, 45, 46, 

47, 48, 49, 60, 62, 54 
decay of, 45 

dry fruits, 44, 46, 46, 47, 48, 62, 54 
explosive, 66 
fleshy, 44, 49, 60, 54 
Fuchs, 319 

Fuchsia, 13, 32, 79, 247, 248, 319 
Fuller's teasel, 273 
Fumculus, 21, 39, 40 



Gaertneria, 280 

Gaillardia, 280 

Galanthus nivalis, 311 

Galen, 318 

Galium, 126, 271 

Gametes, 5, 40, 41 

Gamopetalous flowers, 15, 80, 153 



Gamopetaly, 15, 80, 153 
Gamosepalous flowers, 15, 80, 153 
Garnosepaly, 15, 80, 153 
Garcinia family, 196 
Garcinia mangostana, 196 
Garden beets, 206 
Garden cress, 202 
Gardenia jasminoides, 271 
Gaultheria, 215 
Gazanias, 279, 280 
Geitonogamy, 28 
Genera founded, 324 
"Genera Plantarum," of Bentham 
and Hooker, 336 

of cle Jussieu, 329 

of Endheher, 334 

of Linnaeus, 325 
Generative nucleus, 38 
Generic names, formation and use of, 

141-148 
Gentian, 217, 218 

blue, 218 

fringed, 218 

pollen, 18 
Gentian family, 217, 218 

order, 217 
Genliana, 18, 218 
Gentiana crinita, 218 
Gentianaceae, 217, 218 
Gentianales, 217 
Genus, concept of, 141-148 
Geraniactae, 187, 188 
Geraniales, 186 

Geranium, 48, 76, 78, 187, 188 
Geranium, 48, 76, 78, 120, 187, 188 

maculatum, 187 
Geranium family, 187, 188 
Geranium order, 186 
Germinating pollen grains, 18, 38 
Geum, 66 
Giant cactus, 17, 20, 21 

granadilla, 198 

sahuaro (or saguaro), 253 

spider plant, 201 
Ginger, 315 
Ginger family, 315 
Ginger lily, 315 
Ginseng, 108, 267, 267 
Ginseng family, 267, 267 



410 



FLOWERS AND FLOWERING PLANTS 



Gladiolus, 70, 312 
Glasswort, 106 
Gleditsia triacanthos, 235 
Globe artichoke, 281 

daisy, 17 

flower, 175 
Glomerule, 110 
Glumes of grasses, 301, 302 
Glycyrrhiza glabra, 237 
Gnaphahum, 283 
Golden bells, 223 

currant, 240 
Goldenrod, 24, 109, 282 
Gooseberry, 50, 239 
Gooseberry family, 239, 239 
Goosefoot, 102, 205, 206 
Gossypium, 44, 56, 63, 180 

arbor eum, 180 

brasiliemte, 180 

herbaceum, 180 

hirsutum, 180 
Gourd, pollen of, 18 
Grain, 47 

Grain sorghums, 308 
Grama grasses, 303, 304, 305 
Graminales, 299 
Graminear, 30, 300-308 
Grariadilla, 198 
Grape, 7, 23, 255, 256 
Grapefruit, 191 

embryo of, 59 
Grass of Parnassus, 19 
Grass order, 299 
Grasses, 7, 21, 30, 31, 47, 63, 

30O-308 
Gray, Asa, 346 
Green ash, 23 
Greens, 206 
Grindeha, 108 
Grossularia, 239 
Grossulariaceae, 239, 239 
Ground cherry, 224 

fruit of, 64 
Groundsel, 277 
Groups of plants, 140-144 
Growth, determinate, 109 

indeterminate, 105 
Guava, 50, 244 
Gum, blue, 244 



Gum, red, 241, 244 

sweet, 241 
Gum arabic, 235 
Gumbo, 181 
Gums, 241, 244 
Gun cotton, 180 
Guttiferaceae, 196 
GymnocladuSj 66 
Gymnosperrns, 30 
Gynandrium, 317 
Gynoecium, 19 
Gypsophila, 204 

H 

Hackberry, 184 

Haematoxylon campechianum, 237 
Hamamelidaceae, 240, 240 
Hamamelis, 240, 240 

Virginians, 240 
Hard maple, 261, 262 
Harebell, 100, 274, 275 
Hassal, 31 

Hay-fever weeds, 279, 280 
Hay sorghums, 308 
Hazel, 22, 30, 30 46 

American, 266 

European, 266 
Head, 108, 108 
Heather, 211, 214, 215 
Heather family, 214 
Heather order, 214 
Hedera helix, 267 
Hedge mustard, 202 
Hedychium coronarium, 315 
Helenieae, 279, 280 
Helenium, 82, 277 
Hehantheae, 277, 279, 280 
Helianthus, 43, 109, 277, 279, 280 
Helichrysum, 283 

bracieatum, 283 
Hemicellulose, 60 
Hemlock, poison, 269 
Hemp, 7, 23, 185 

experiments with, 323 

sisal, 311 

"Hen and chickens," 242 
Henbane, 224 
Henna, 248 



INDEX 



411 



Herb mercury, experiments with, 323 
Herbaceous types, 158 
Herbae, 323 
Herbals, 319-320 
Herbarium, care of, 369 
Hercules club, 267 
Hesporidmm, 51, 54 
Hevea brasiliensis, 194 

guyanensis, 193, 194 
Hibiscus, 7, 18, 19, 180 

esculentus, 180 

stamens, 82 
Hickory, 7, 23, 30, 264 
Hicoria, 30, 46, 65, 106, 264 

laciniosa, 264 

ovata, 264 

pecan, 264 
High flowers, 74, 105, 151, 152, 154, 

276, 284, 353 
Highbush cranberry, 272 
Hilum, 61 

Hippeastrum reginae, 31 1 
Hippocastanaceac, 260 
Ihraca, 46 

Historia Plantarum of John Ray, 323 
Hitchcock's Methods of Descriptive 

Systematic Botany, 160 
Holcus sorghum, 308 
Holly, 257, 268 
Holly family, 257, 258 
Hollyhock, 79, 181 
Honesty, 202 
Honey, 35 

Honeybee, pollen load of, 34 
Honeylocust, 239 

Honeysuckle, 7, 16, 79, 4, 271, 272 
Honeysuckle family, 271, 272 
Hooker, J. D., 335 

W. J., 335 
Hops, 30, 185 
Hordeae, 303, 305 
Ifordeum, spike of, 107, 305 

nodosum, 302 
Hornbeam, 30, 64 
Horse chestnut, 111, 260 
Horsemint, 231 
"Houseleek," 242 

offsets of, 71, 72 
Houstonia, 81 



Huckleberry, 215 

Humming birds as pollinating 

agents, 32 

Humulus lupulus, 30, 185 
Hungarian grass, 307 
Hutchinson, 151 
Hyacinth, 105, 292 
Hyacinthus, 105, 292 

bulb of, 70 
Hydrangea, 238, 239 

cinerea, 1 10 

Hydrangea family, 238, 239 
Hydrangeaceae, 238, 239 
Hydrates, 313 
Hydrastis, 175 

J/ydrocharis morsus-ranae, 310 
Hydrophyllacfae, 223 
Hydrophyllurn canadense, 223 
Hymenaea cojirbaril, 235 
Hymenocallis americana, 311 
Hyoscyamus niger, 224 
Ilypericum, 196 
Hypocotyl, 58 
Hypogynae, 286 

Hypogynous flowers, 12, 13, 75, 86 
Hypogynous monocotyledons, 286 
Hypogyny, 12, 13, 75, 99, 153, 286 
Hypopitys, 105 
Hypoxis, 311 



1 



Iberis, amara, 202 

Ilex aquifolium, 258, 268 

opaca, 258 

paraguayensis, 258 
Impatiens, 32, 33, 92, 192 

fulva, 192 

noli- me-tangere ,192 
Imperfect flowers, 22, 23, 153, 154 
Inbreeding, -28 

Incomplete flowers, 6, 7, 22, 25 
Indehisrent fruits, 45, 46, 47, 60, 54 
Indented keys, 161, 162 
Indeterminate growth, 105 
Indian corn, 308 

jujube, 257 

lotus, 176 
Indications of relationships, 81 



412 



FLOWERS AND FLOWERING PLANTS 



Inferior ovary, 12, 13, 77, 79, 81, 86, 

99, 153 
Inflorescence, 104-113 

biology of, 112 

compound, 110 

kinds of, 105 

oblique, 111 

relationships of, 104 
Insectivorous plants, 136 
Insects and flowers, 32, 33, 34, 136 
Integuments of ovules, 39, 60 
Internodes, 119, 120, 121 
Intine, 18, 18 
Inuleae, 279, 282-283 
Involucre, 24, 112, 112, 193, 277 
Ipecacuanha, 271 
Ipomoea, 14, 81, 222 

batatas, 223 

purpurea, 222 
Indaceae, 312, 312 
Iridales, 310 

Iris, 13, 22, 44, 56, 68, 68, 90, 91, 
102, 312, 312 

capsule of, 44 

family, 312-316 

florentina, 312 

order, 310 

rhizome of, 68 
Ironweed, 64, 279, 282 
Irregular flowers, 15, 16, 35, 83, 84, 

85, 153 

Ivory palm, 59 
Ivory, vegetable, 56, 59 
Ivy, Boston, 256 

English, 267 

poison, 262 



Jacaranda, 227 

ovalifolia, 227 

Jack-in-the-pulpit, 70, 107, 296, 297 
Jack tree, 227 
Japanese barberry, 173 

pagoda tree, 237 

paper plant, 24 

persimmon, 216 
Jasmine, 219, 271 

rock, 212 



Jasminum, 14, 81, 219 

Jerusalem artichoke, 69 

Jessamine, 14, 81 

Jewelweed, 192 

Jimson weed, 14, 224 

Job's tears, 308 

Joe Pye weed, 282 

Johnson grass, rhizome of, 68 

Juanabana, 170 

Juglandaceae, 263-264 

Juglans, 5, 22, 66, 106, 263, 264 

cinerea, 263, 264 

nigra, 263, 264 
Juglans regia, 264 
Juncaceae, 101, 294, 294 
Juncus balticus, 294 
June grass, 64 
Jussieu, de, A. L., 329, 330, 331 

system of classification of, 330-331 
Jussieu, de, B., 329, 330 

K 

Kafir sorghum, 308 
Kaki plum, 216 
Kalmia, 120, 214, 215 

latifoha, 214, 214 
Karaunda, 219 

Keel (in legumes), 15, 16, 236 
Kernel of wheat, 43 
Kew Garden, 151 
Keys, 161-164 

artificial, 161 

bracket, 162, 163, 164 

dichotomous, 163 

indented, 162, 163, 164 

natural, 161, 162 
King orange, 191 
Kochia scoparia, 206 
Kohlrabi, 202 
Krameria, 66 

Kruydtboeck, of de TObel, 322 
Kuhnistera, inflorescence of, 106 



Labels, for herbarium specimens 

364, 368-369 
Labiatae, 36, 98, 230, 231 
Lactuca, 109, 281 



INDEX 



413 



Lady's slipper, 33, 37, 316, 317 

Lagerstroemia, 248 

Lamb's quarters, 66, 206, 207 

Lamiaceae, 230 

Lamiales, 229, 232 

Lamium, 16, 92 

amplexicaule, 231 
Lanceolate leaf, 130, 130 
Lantana camara, 230 

sellowana, 230 
Larkspur, 33, 92, 93, 169, 175 
Lateral buds, 119, 120, 121, 126 
Lathyrus, 90, 236 

odoratus, 90, 237 
Lauraceae, 171-172 
Laurel, 171, 172, 214, 215 
Laurel family, 171-172 
Laurus nobilis, 172 
Lavender, 231 
Lavandula spica, 231 
Lawsonia inermis, 248 
Lead wort family, 96, 213, 213 
Lead worts, 213 

Leaf outlines, 130, 131, 133, 134, 136 
Leaf scars, 120, 121 
Leaflets, 128, 129 
Leaves, 125-136 
alternate, 127 

arrangement of, on stems, 126, 127 
bases of, 131-132 
auric ulate, 131 
clasping, 132 
connate, 131, 132 
cordate, 131 
decurrent, 131, 132 
hastate, 131 
oblique, 131, 132 
peltate, 130, 131 
perfoliate, 131, 132 
reniform, 131 
saggitate, 131 
sheathing, 132 
blade of, 126, 12&-135 
compound, 128, 129 
edges of (see Edges of leaves) 
opposite, 126 
simple, 128, 129 
tips of (see Tips of leaves) 
Leechee (or litchi), 261 



Legume, fruit of, 48, 54, 79, 236 
Leguminosae, 36, 48, 79, 235, 236, 
236, 237 

Lemnaceae, 297 

Lemon, 51, 191 

Lens esculenta, 237 

Lentibulariaceae, 225, 229 

Lenticels, 122, 124 

Lentil, 237 

Leontopodium alpinum, 283 

Lepidium sativum, 202 

Lettuce, 64, 109, 281 

Leucoju m vernum, 311 

Lewisia rediviva, 205 

Ligustrum, 111 

Ligule, 301 

Lilac, 93, 111, 218, 219 

Lihaceae, 101, 102, 291, 292 

Liliales, 291 

Lihes, 22, 70, 101, 102, 291, 292 

Lilium, 70, 82, 101, 152, 292 

Lihum candidum, 292 

longijlorum, 292 

tignnum, 292 

Lily family, 101, 102, 291, 292 
Lily-of-the-valley, 14, 91, 105 
Lily order, 291 
Limb of corolla, 15 
Limonium, 213 
Linaceae, 189, 189, 190 
Linden, 17, 181 
Linden family, 181, 181 
Lindley, 333 

lAnnaea borealis, 142, 272, 272 
Linnaeus, 104, 324, 326, 326, 327, 
328 

and nomenclature, 147 

system of classification of, 325-327 
Linum, 76, 86, 93, 189-190 

grandiflorum, 190 

perenne, 190 

usitatissimum, 189 
Liquidambar styraciflua, 241 
Liquorice, 237 
Liriodendron, 76, 96 

tulipifera, 170 
Litchi, 261 

chinensis, 261 
Live-for-ever, 242 



414 



FLOWERS AND FLOWERING PLANTS 



Limstona chinensis, 298 
Loam, 249 

vulcania, 249 
Loasaceae, 249 
Loasales, 243, 249 
Lobelia, 107, 275 

cardinalis, 275 
Lobelias (or do 1'Obel), 322 
Local floras, 373-376 
Loco weed, 237 
Locust, 237 
Lodicules, 302 
Loganberry, 12, 51, 52 
Logwood, 237 
Lomatium, 48, 108 
Lomcnt, 48, 54 
London plane, 241 
Long moss, 313 

Lonicera, 7, 16, 32, 77, 79, 84, 87, 
100, 272 

involucrata, 272 

japonica, 272 

periclytnenum, 272 

sempervirenis, 272 

tatarica, 272 

Loosestrife family, 248, 248 
Loranthaccac, 259 
Lotus, American, 176 
Low flowers, 74, 104, 353 
Lucerne, 237 
Luff a cylindnca, 252 
Lunaria annna, 66, 202 
Lychnis, 204 

Lycium halimifohum, 224 
Lycopersicon esculentum, 224 
Lythraceae, 248, 248 
Lythrum alatum, 248 

M 

Mace, 171 

Madder, 100, 270, 271 

Madder family, 100, 270, 271 

order, 270 
Magnol, Pierre, 169 
Magnolia, 74, 75, 79, 86, 96, 152, 169, 

169 

Magnolia family, 169, 169, 170 
Magnolia order, 168 



Magnolia acuminata, 169 

grandiflora, 169 

soulangeana, 169 

Magnoliaceae, 95, 150, 151, 169, 170 
Magnoliales, 150, 168 
Mahogany, mountain, 76, 76 
Mahonia aquifolium, 174 
Maize, 7, 23, 28, 304, 308 

experiments with sex of, 323 
Maize grasses, 304, 308 
Male sex cells, 26, 28, 38, 40, 41 
Mallow family, 179, 180 
Malus, 76, 233, 234 
Malva, 17, 18, 90, 180, 180 
Malvaceae, 90, 96, 179, 180 
Malvales, 179 
Mandrake, 174 
Mangosteen, 196 
Mangrove, 60, 61, 245, 246 
Mangrove family, 245, 246 
Manihot utilissima, 194 
Manila hemp, 314 
Manuals, 165, 371-383 

ranges of (map), 374 
Maple, hard, 261, 262 

Norway, 262 

silver, 261, 262 

sugar, 261, 262 

sycamore, 262 
Maple family, 261, 262 
Maple order, 260 
Maple sugar, 262 
Maples, 7, 46, 161, 260, 261, 262 
Marantaceae, 315 
Marguerite, 283 
Mangold, 279, 281 
Mariposa lily, 292 
Marram grass, 68, 307 
Marsh mangold, 75, 174, 175 
Martynia, 48 
Mastic tree, 262 
Mate, 258 

Materia medica, of Dioscorides, 318 
Matrimony vine, 224 
Maturation of seed, 41 
Maxillaria, 55 
May apple, 174 
Maydeae, 304, 308 



INDEX 



415 



Meadow fescue, 306 

rue, 27, 111 
Medicago sativa, 237 
Meibomia, 49 
Melissa, 17 
Alentha, piperita, 69, 231 

rhizomes of, 69 

spicata, 231 
Mentzelia, 231 
Mercerized cotton, 180 
Mercurialis annua, 323 

experiments with sex of, 323 
Mericarp, 47 
Mertensia alpina, 225 
Mescal, 311 
Methods of Descriptive Systematic 

Botany, of Hitchcock, 160 
Mexican fire plant, 193 
Mez, Carl, 150 
Micropyle, 39, 41 
Microscopes, dissecting, 369, 360 
Middle ages, 319 
Mignonette, 203 
Mignonette family, 203, 203 
Migration, aids, 63-64 

capacity for, 62 

velocity of, 72 
Milfoil, 283 
Milkweed, 63, 90, 108, 220, 221 

swamp, 220 

Milkweed family, 220, 221 
Millet, 307 

pearl, 307 

Millet grasses, 304, 307 
Milo sorghum, 308 
Mimosa family, 235 
Mimosa pudica, 235, 236 
Mimosaceae, 235 
Mimulus, 18, 226 
Mint family, 230, 231 
Mint order, 229 
Mints, 15, 16, 36, 92, 98, 217, 222, 

231 

Mirabilis, 142, 208, 208, 209 
Miscanthus sinensis, 308 

var. zebrinus, 308 
Mistletoe family, 259-260 
Mitchella, 28, 106 
Mitella, 238 



Miterwort, 238 
Mixed buds, 120 
Mobility, 62, 72 
Moccasin flower, 33, 316, 317 
Modern botany founded, 322 
Modifications for migration, 62-72 
Momordica balsamina, 252 
Monarda didyma, 231 

fistulosa, 231 

Moneses uniflora, 214, 214 
Monkey flower, 226 
Monkshood, 16, 44, 89, 169, 174, 175 
Monoelinous flowers, 23, 25, 153 
Monocliny, 23, 25, 153 
Monocotyledons, 284-317 

embryo and seed of, 285 

cpigynous types of, 309 

floral anatomy of, 284, 286 

growth and life of, 285 

hypogynous types of, 286 

relation to dicotyledons, 157-159, 

285 

Monoecious species, 23, 26, 28, 154 
Monophylesis, 154 
Monstera deliciosa, 296, 297 
Monterey cypress, 140 
Moonseed, 68 
Mooriwort, 66, 202 
Moraceae, 184, 186 
Morning glory, 14, 68, 81, 222, 222 
Morning-glory family, 222, 222 
Morongia uncinata, 235 
Morphology, 155 
Morus, alba, 184 

experiments with sex of, 323 

nigra, 184 
Mountain ash, 110 

laurel, 214 

mahogany, 76 

timothy, 307 

Movements of plants, 62-72 
Mulberry, 7, 23, 184, 186 

experiments on sex of, 323 

family, 184, 186 
Multiple fruits, 53, 54 
Musa, 314 
Musa ensete, 314 

sapientum, 314 

textilis, 314 



416 



FLOWERS AND FLOWERING PLANTS 



Musaceae, 313, 314 
Muskmelon, 261, 251 
Mustard, 9, 201, 202 
Mustard family, 201, 202 
Mutisieae, 279, 281 
Myosoiis, 225, 226 
Afyosurm, 11, 74, 76 
Myristica fragrans, 48, 171 
Afyristicaceae, 171, 171 
Myrrh, 108, 269 
Myrrhis odorata, 108, 269 
Myrtaceae, 243, 244 
Afyrtales, 243, 254 
Myrtle, 13, 243, 244, 254 

relationships of, 243 
Myrtle family, 243, 244 
Myrtle order, 243, 254 
Afyrtus, 13, 244 

communisj 244 

N 

Naked buds, 120 

Names of plants, 137, 139, 1 10-148 

Narcissus, 311, 311 

Narcissus jonqnilla, 311 

poeticus, 311 

pseudonarcissus, 311 

tazetta, 311 

Nardostachyos jatamawn, 273 
Nasturtium, 33 
Natural keys, 139, 161, 102 
Natural system of classification, 139, 
143, 15&-160, 161, 323, 329-353 
Navel orange, 43, 191 
Nectar, 35 
Nectaries, 35 

of buckthorn, 36 

of buttercup, 36 

of columbine, 36 

of violet, 35 
Needle 1 grass, 307 

Nelson's New Manual of Botany of 
the Central Rocky Mountains, 
163 
Nelumbium luteum, 176, 176 

speciosum, 176 
Nemophila insignis, 223 
Nepenthes ampullaria, 32. 136 



Nepeta, 84 
Nerium, 220 
Nettle, 22, 110, 186 

experiments with, 323 
Nettle family, 186. 186 
New England aster, 282 
New Manual of Botany of the Central 
Rocky Mountains, of Coulter 
and Nelson, 163 
New York aster, 282 
Nicoliana, 5, 44, 92, 224 

tabacum, 141, 224 
Nigh-blooming corona, 253 
Nightshade, 224 
Nightshade* family, 223, 224 
Nodes, 119, 120, 121 
Nomenclatorial practices, 146 
Nomenclature and relationships, 141 

and taxonomy, 144 

stability desired, 145, 147, 148 
Nopalca cochinettifcra, 253 
Notebooks for the collector, 354-355 
Nucellus, 39 
Nucleus, equatorial, 40, 41 

primary embryosac, 40, 40, 41 
Nuphar, 176 
Nutmeg, 47, 171, 171 
Nutmeg family, 17J, 171 
Nuts, 46, 47, 65, 263, 264, 266 
Nyctaginaceae, 208, 208 
Nyinphaea, 44, 176 
Nymphaeaccac, 175, 176, 176 



Oak, 4, 7, 23, 30, 46, 106, 161, 264, 
265 

black, 161 

bur oak, 265 

cork oak, 265 

English oak, 264 

live oak, 264, 268 

pin oak, 265 

red oak, 265, 266 

scarlet oak, 265 

white oak, 161, 264, 265 

willow oak, 264, 266 
Oat grasses, 303, 306, 306 



INDEX 



417 



Oats, panicle of, 306 

wild oats, 305 
Obcl, de T, 322, 322 
Oblique inflorescence, 1 1 1 
Ocrea, 207 

Odoiitoglossum crisp um, 317 
Odotttospermum pyginaeum, 283 
Oenotkera, 32, 247 
Off sots, 71, 72 
Offshoots, 67 
Oil, 244 
Okra, 181 

Olea euro pea, 60, 218, 219 
Olracear, 218, 219 
Oleander, 220 
Oleaster family, 258-269 
Olive, 50, 60, 218, 219 
Olive family, 218, 219 
Onagracear, 246-247, 248 
Oncidium vanxosum, 317 
Onion, 4, 70, 108, 292 
Opium, 200 

poppy, 200 

OppoMtarfoliae, 349, 350 
Opposite leaves, 120 
Qpuntia, 89, 252, 253 
Orange, 43, 51, 62,90, 191 
king, 191 
navel, 43, 191 
seedless, 191 
sour, 191 
sweet, 191 
trifoliate, 191 
Orange family, 190, 191 
Orbicular leaf, 130, 131 
Orchard grass, 305 
Orchid family, 35, 37, 82, 85, 102, 

316, 317 
order, 315 

Orchidaceae, 35, 82, 85, 102, 316, 317 
Orchidales, 315 
Orchids, 13, 16, 21, 33, 35, 82, 84, 

91, 102, 315, 316 
Orchis, 33, 35, 84, 91, 316 

rotundifolia, 106 
Order, concept of, 142, 143 
Oregon grape, 174 
Organs, accessory, 3, 6 
essential, 3, 6 



Oriental persimmon, 216 
Ornamental grasses, 308 
Ornamental orchids, 317 
Ornithogalum, 292 
Oiobanchaceae, 227, 228 
Oiobanche americana, 228 
Orrib root, 312 
Orthotropous ovule, 39 
()t yzri saliva, 301, 306 
Oryzeac, 303, 306 
Osage orange, 23, 109, 185 
Osier (red), 268 
Ostrya, 30 

Outline of leaves, 130, 131, 132, 
133, 135 

cuneate, 130, 131 

deltoid, 130, 131 

elliptical, 130 

lanceolate, 130 

linear, 130 

oblong, 130 

orbicular, 130, 131 

ovate, 130, 131 

palmate, 131 

peltate, 131 

sec ul ate, 130, 131 

spatulate, 130, 131 
Ovary, 3, 5, 6, 19, 39, 86 

change to fruit, 41 

compound, 3, 0, 19, 86 

infenor, 12, 13, 86 

simple, 6, 25 

superior, 11, 12, 86 
Ovate leaf, 130, 131 
Ovules, 5, 5, 6, 20, 39, 41, 86 

anatropous, 39, 39 

campylotropous, 39, 39 

change to seed, 6, 9, 41 

form of, 39 

number of, 20, 21, 86 

orthotropous, 39, 39 

position of, 21, 39, 39 
Oxalidaceae, 188, 189 
Oxalis, 66, 90, 188 
Oxalis, 66, 90, 188 

montana, 188 
Oxalis family, 188, 189 
Oyster, vegetable, 281 



418 



FLOWERS AND FLOWERING PLANTS 



Paeonia, 31, 76, 175 
Pagoda tree, 237 
Palea, of grasses, 302 
Palet, of grasses, 302 
Palmaceae, 297, 298 
Palmales, 297 
Palmate leaf, 129 
Palms, 291, 297, 298 
Pampas grass, 308 
Panax, 108 

Pandanaceae, 102, 290 
Pandanus utilis, 290 
Paniceae, 304, 307 
Panicle, 110 
Panicum, 110, 302, 307 
Pansy, 197 
Papaver, 44, 89, 200 

rhoeas, 90 

somniferum, 200 
Papaveraceae, 199, 200 
Papaveralcs, 199 
Papaw family, 170, 199 
Papaya family, 198 
Paper birch, 266, 266 
Paper mulberry, 189 
Paper-white narcissus, 311 
Papilionaceae, 235, 236, 237 
Pappus, 46, 277, 278, 279 
Papyrus, 300 
Paraguay tea, 258 
Parasitic flowering plants, 15, 228 
Parnassia, 19 
Parnassus, grass of, 19 
Parsley family, 102, 268, 268 
Parsley order, 254, 266 
Parsnip, 108, 269 
Parthenocissus, 110, 256 
Partridge berry, 28, 106 
Pasque flower, 14, 43, 64, 104, 175 
Passi flora quadrangidaris, 198 
Passifloraceae, 198 
Passion flower, 198 
Passion-flower family, 198 
Pastinaca saliva, 269 
Pea, 16, 48, 84, 90, 236, 237 
Pea family, 235, 236, 237 
Peach, 12, 60, 234 



Peach-leaved willow, 209 
Peanut, 57, 237 
Pear, 51, 234 

alligator, 172 
Pearl millet, 307 
Pecan, 264 
Pelargonium, 188 
Peltandra, 107 
Pennisetum glaucum, 307 

ruppelii, 308 

villosum, 308 
Penny cress, 202 
Pentstemon, 226 
Peony, 31, 76, 175 
Peperomia, 178 
Pepo, 50, 54, 251 
Pepper, 60, 177 

black, 177 

red, 178 

white, 177 

Pepper family, 177, 178 
Pepper grass, 202 
Pepper tree, 262 
Peppermint, 231, 231 

rhizome of, 68, 69 
Perennials, 117, 119, 120 
Perfect flowers, 7, 22, 25, 153 
Perianth, 3, 4, 6, 14, 22, 25, 86, 125 
Pericarp, 50 

Perigynous flowers, 12, 13, 87 
Perigyny, 87 
Periwinkle, 219, 220 
Per sea gratissima, 172 
Persimmon, American, 215, 216 

Japanese, 216 
Petals, 3, 4, 6, 14, 17, 25 
Petaly, 162 
Petiole, 126 

Petroselinum hortense, 269 
Petunia, 224 
Petunia violacea, 224 
Phacelia, 93 

whitlavia, 223 
Phalaenopsis, 33, 84, 316 
Phalarideae, 304, 306 
Phalaris arundinacea, 306 

var. picta, 306 

canariensis, 306 
Phaseolus vulgaris, 236, 237 



INDEX 



419 



Philadelphia, 239 
Phi e urn alpiniim, 307 

pratense, 307, 307 
Phlox, 221, 222 
Phlox, 76, 96, 221, 222 

dtvaricata, 222 

pilosa, 221, 222 

stansburyi, 222 
Phlox family, 221, 222 
Phlox order, 221, 225 
Phoenix, 68, 298 

dactylifera, 298 
Phragmites com mums, 304 
Physalis alkakengi, 224 
Physocalymma scaberrimum, 248 
Phytelephas, seed, 56 
Phytopinax, of Bauhin, 321 
Pickerel weed, 293 
Pickerel-wood family, 293, 294 
Pigweeds, 207 
Pih nut, 46 

Pimenta offldnalis, 244 
Pimpinella anisum, 269 
Pincushion flower, 273 
Pine, 140, 146 
Pineapple, 313 
Pineapple family, 313 
Pine sap, inflorescence of, 105 
Pink family, 204, 205 
Pink order, 203 
Pinks, 195, 204, 205 
Pinus ponderosa, 140 

resinosa, 146 

ngida, 146 

strobus, 146 
Piper betle, 178 

cubeba, 177 

nigrum, 50, 177 
Piperaceae, 177, 178 
Pipewort, 295, 296 
Pistacia, 263 

era, 263 

Pistachio nut, 22, 263 
Pistils, 3, 6, 19, 20-22, 39-41, 73 

compound, 3, 20 

simple, 20 

structure of, 3, 20 
Pimm, 16, 48, 84, 90, 236, 237, 237 

sativum, 236, 237 



Pits, 50, 60 

Pitcher plants, 32, 136 
Pithecoctenium, seed, 63 
Pittosporum, 120 
Placenta, 21, 39 

axillary, 22 

free central, 22 

parietal, 22 
Piano tree, 241, 242 
Plant groups, chart of, 169 

cross lines of, 157 

extension of, 158 

lines of development shown, 156, 
159 

symbols used, 158, 159 
Plant names, origin of, 140-148 
Plant presses, construction of, 361- 

363 

Plantaginaceae, 212, 213 
Phntago, 106, 107, 212 

lonceolata, 213 

major, 212, 213 

ovnta, 213 

purshii, 141, 213 
Plantain, 107, 212, 213 
Plantain family, 212, 213 
Plants, classification of, 137-166 

in America, 346 

in ancient times, 318 

artificial system, 139 

basis, 136 

history of, 318-353 

influence of European system of, 
345 

natural system of, 139 

phylogenetic system of, 139 

principles of, 139, 148 
Platanaceae, 243, 242 
Platanus, 109, 241 

acerifolius, 241 

occidentals, 241 

orientalis, 241 
Platanthera, nectary, 35 
Plato, 318 

Platycodon grandiflorum, 275 
Pliny, 318 
Plum, 12, 21 

Plumbaginaceae, 96, 213, 213 
Plumbago, 213 



420 



FLOWERS AND FLOWERING PLANTS 



Plumule, 58 
Poa, 302, 305 

pratensis, 302 
Poaceae, 300 
Pocket lenses, 369, 359 
Pod corn, 308 
Podophyllurn pcUatum, 174 
Poet's narcissus, 311, 311 
Poinciana, 235 
Poindana pulcherrima, 235 
Poimelha, 24, 25, 112, 193 

keterophylla, 193 

pulchernma, 193 
Poison hemlock, 269 

ivy, 118, 262 

oak, 262 

sumac, 262 

Poisonous plants, 223, 237, 269 
Polemoniaceae, 96, 221, 222 
Polemoniales, 221, 225 
Polish wheat, 305 
Pollen, 18, 31, 34, 38 

sterile, 37 

tube, 18, 37, 38, 40, 41 
Pollen grams, 5, 8, 17, 18, 31, 34, 38 

germination of, 38, 40, 41 
Pollination, 4, 8, 16, 27, 29-31, 40 

in grasses, 31 

in mints, 32, 36 

in orchids, 37 

Pollination and zygomorphy, 35-37 
Pollima, 84, 220, 317 
Polygamous species, 23 
Polugonaceae, 207, 208 
Polygonum, 208 

Polypetalous flowers, 3, 7, 11, 15, 153 
Poly pet aly, 15, 153 
Polyphylesis, 154 

Polysepalous flower*, 3, 7, 11, 15, 153 
Polysepaly, 15, 153 
Pome, 51, 54 

Pomegranate, 60, 66, 244, 246 
Pomegranate family, 244, 246 
Pondweed family, 288, 288 
Pondweeds, 292 
Pontederia, 293, 294 
Pontederiaceac, 293, 294 
Poor man's bananas, 170 
Pop corn, 308 



Poplar, 30, 106, 209, 210 

Poppy, 89, 90, 199, 200 

Poppy family, 199, 200 

Poppy order, 199 

Popular conception of fruits, 43 

Populus, 30, 106, 141, 164, 209, 210 

alba, 210 

ang ustifo Ha , 164 

balsaimfera, 164 

bolleana, 210 

ddtoidcx, 141, 210 

nigra itahca, 210 

occidentalis, 164 

Iremuloides, 164 

unslizemi, 164 
Portable presses, 360-363 
Porlulacaceae, 205 
Portulaai grmidijlora, 205 
Pot herbs, 206 

Potamogcton natanv, 288, 288 
Potato, 43, 69, 223, 224 

floral diagram of, 92, 224 

fruit balls of, 157 

Irish, 223, 224 

sweet, 222, 223 
Potato family, 223, 224 
Poulard wheat, 305 
Preparing specimens, 354-369 
Presses, plant, 356367 

care of, 365 
Prickly pear, 262, 253 
Primary embryosac nucleus, 39, 40, 

41 
Primitive flowers, 73-75, 104, 149- 

159 

Primrose, 21, 22, 76, 79, 86, 93, 211, 
211 

Chinese, 212 

evening, 246, 247 
Primrose family, 211, 212 

order, 211 
Primula, 76, 79, 86, 93 

farinosn, 211 

ainensis, 212 

Pnmulaceae, 211, 212, 247 
Pnwulales, 211 

Principles of classification, 151-159 
Privet, 111, 219 
Proso, 302 



INDEX 



421 



Protaridry, 28 

Proteins, 59 

Prunaceae, 233 

Prunus, 9, 60, 108, 233, 234 

besseyi, 141 

cerasus, 107, 141 
Psidium cattleianum, 244 

guajava, 244 

Psychotria ipecacuanha, 271 
Pulque, 311 

Pulsatilla hirsulissima, 43, 104, 175 
Pumpkin, 251, 251 
Pumpkin family, 261, 252 
Puncture weed, 64 
Punic, apples, 245 
Punica, 50, 66, 246 

granatuin, 246 
Punicaccae, 244, 245 
Purslane, 205 

family, 205 
Pusloy, 205 
-Pyrethrum, 283 
I'yrola, 17 
Pyrus, 76, 233, 234 

Q 

Quack grass, rhizomes of, 68 
QuamocUt pinnata, 222 
Qttercus, 4, 30, 100, 142, 152, 264, 
265 

alba, 146, 161, 264, 265 

boreahs, 146, 261, 265 

macrocarpa, 265 

palustriSj 265 

robwr, 264 

sMbcr, 265 

velutina, 161 

virginiana, 264, 266 
Quince, 51 
Quinine, 271 

R 

Raceme, 105, 106 

Racemose inflorescence, 105, 106 

Rachilla, 110, 301 

Rachis, 110 

Radicle, 58 



Radish, 48, 86, 202 

Raffia, 298 

Rafflesia, 15 

Ragweeds, 279, 280, 282 

Ragworts, 279, 281 

Ramies, 74, 79, 150, 151, 168, 232, 

233, 286 

Ranges of manuals (map), 374 
Ranunculaceae, 95, 174, 175, 233 
Ranunculus, 152 
Raoulia, 283 
Raphanus, 48, 86, 202 

sativus, 202 
Raphe, 61 
Raphia ntffia, 298 
Raspberry, 11, 49, 71 
Ravenala madagascariensis, 314 
Ravenna grass, 308 
Ray, John, 322, 323 

system of classification of, 323 
Ray flowers, 111, 276, 277, 278 
Razouniowftkia, 260 
Red gum, 242, 244 

oak, 112, 264, 266 

osier, 268 
Redbud, 235 
Redtop grass, 307 
Reed grass, 304 
Regional floras, 372-376 
Regular flowers, 15, 83, 153, 159 
Relationships of flowers, 151-159 
Reproduction, 2, 3, 26-61 
Reseda odorala, 203, 203 
Resedaceae, 203, 203 
Rcsms, 244 
Rex begonia, 250 
Rhamnaceac, 256, 257 
Rhamnus, 35, 35, 50, 267 

purshiana, 257 
Rheum rhaponticum, 208 
Rhizomes, 68, 69, 136 
Rhizophora, 60, 61, 246, 246 
Rhizophoraceae, 245, 245 
Rhododendron, 142, 215 
Rhododendron californicum, 215 
Rhubarb, 208 
Rhus, 262 
Ribes, 9, 106, 239, 240 

aureum, 105, 240 



422 



FLOWERS AND FLOWERING PLANTS 



Ribes, nigrum, 239 

rubrum, 239 
Ribbon grass, 306 
Rice grasses, 302, 303, 306 
Richardia, 107 

aethiopica, 297 
Ricinus commums, 193 
Robinia hi spiel a, 237 
Rock jasmine, 212 
Root sprouts, 115 . 
Root system , 116-117 

adventitious, 117 

primary, 117 

secondary, 117 
Roots, 115-119 

adventitious, 117 

aerial, 115, 118 

fascicled, 117 

fibrous, 116 

fleshy, 115, 116 

fusiform, 117 

napiform, 117 

tap, 115, 117 

woody, 116 

Roripa nasturtium-aqvaticum, 202 
Rosa, 142, 234 
Rosaceae, 233, 233, 234 
Resales, 232, 243, 254 
Rose, 11, 13, 234 

of Jericho, 283 
Rose family, 233, 234 
Rose mallow, 7, 19, 82 
Rosmarinus officinalis, 231 
Rosemary, 231 
Rose order, 232, 243, 254 
Rosinweed, 108, 108 
Rostellum (in orchids), 217 
Royal palm, 298 
Roystonea regia, 298 
Rubber and rubber plants, 194 
Rubia, 87, 271 
Rubiaceae, 100, 270, 271 
Rubiales, 270 
Rubus, 11, 49, 234 

deliciosa, 34 
Rudbeckia, 280 
Rumex, 46, 207 

acetosella, 207 
Runners, 70, 71, 121 



Ruppia, 29 

Ruscus aculeatus, 122 

Rush, 101, 294, 295 

family, 294, 295 
Russian mulberry, 184 

olive, 259, 259 

sunflower, 25 

thistle, 67 
Ruto, 191 
Rutabaga, 202 
Rutaceae, 190, 191 
Rye, 107, 302, 305 



Saccharine sorghums, 308 

Saccharum ojficinarum, 304, 308 

Sage, 33, 231 

Sagebrush, 283 

Sagittana, 287, 287 

Sahuaro, 253 

Salicaceae, 203, 209 

Salicornia, 106 

Salix, 4, 30, 106, 209, 209 

alba, 210 

amygdaloides, 209 

babylonica, 210 

longifolia, 209 

purpurea, 210 

viminalis, 210 

vitellina, 210 
Salpiglossis sinuata, 224 
Salsify, 64, 281 
Salsolo, 67 
Salt bushes, 205 
Salvia, 33, 231 

azurea, 231 

glutinosa, 33, 36 

officinalis, 231 

splendens, 231 
Samara, 46, 46, 54, 64 
Sambucus, 272 
Sandalwood family, 260 
Sandbar willow, 209 
Sand-binding grasses, 307 
Sandbur, 64, 307 
Sanguinaria canadensis, 200, 200 
Santalaceae, 260 
Sapindaceae, 260, 261 



INDEX 



423 



Sapinrlales, 254 
Sapindus saponana, 261 
Sapodilla family, 216 
fiaponaria, 66 

officinahs, 205 
Sapotaceae, 216 
Sarracenia, 136 
Sarsaparilla, 267 
Sassafras, 172 
Sassafras, 172 
Savastana odoiata, 306 
Saxifraga cernua, 238 
Saxifragaceae, 237, 238 
Scabiosa atropurpurea, 273 
Scabious, 273 
Scarlet plume. 193 
Scheuchzeriaceae, 287 
Schinus molk, 262 
Schizocarp, 47, 54 
,SW//a, 78, 292 
Scirpus, 300, 300 
Screw-pine family, 290 
Scrophularia nodosa, 226 
Scrophulariaceae, 36, 96, 226, 226, 

228 

ticrophulanales, 225 
Seapink, 213 
tfrco/e, 107, 302, 305 
Secondary effects of fertilization, 12 
Sedge family, 299, 300 
Sedges, 30, 299, 300 
Sedum, 242 
Sedum spectabile, 242 

lelephium, 242 
Seedless orange, 191 
Seeds, 6, 8, 9, 21, 41, 42, 66, 68, 55- 
61, 63 

color of, 56 

distinguishing features of, 57 

foods stored in, 59 

germination of, 61 
nature of, 55-61 
number of, 21, 45, 55 

origin of, 55 
Self-fertilization, 8, 28 
Self-pollination, 8, 28 
Sempervivum, offsets, 72 
Senecio, 276, 277 

cruentuSj 281 



Senecioneae, 279, 281 

Senna family, 234, 235 

Sepals, 3, 4, 6, 7, 13, 14, 25 

Serum analysis, 150 

Sesame, 16 

Sesamum, 16 

Sessile leaf, 138 

Sex, nature of, 5, 8, 26, 27, 40, 41 

Sexual cycle in flowers, 41, 323 

Sexual system of classification pro- 
posed by Linnaeus, 325-328 

Sexuality in flowers, demonstrated, 
323 

Shallu sorghum, 308 

Sheepsour, 188 

Shepherd's purse, 44, 91 

Sieve rsia, fruit of, 64 

Siliquo, 48, 54 

Sisal hemp, 311 

Sisymbrium altissimum, 202 

Skunk cabbage, 34, 107 

Slippery elm, 183, 184 

Slipperwort, 226 

Smilax, 49 
herbacea, 34 

Snails as pollinating agents, 32 

Snakeroot, 175 

Snapdragon, 16, 21, 33, 36, 77, 96, 
98, 217, 226 

Snapdragon family, 96, 226, 228 

Snapdragon order, 225 

Snowberry, 272 

Snowdrop, 311 

Snowflake, 311 

Snow-on-the-mountain, 112, 193 

Soapberry, 260, 261 

Soapberry family, 260, 261 

Solanaceae, 96, 98, 223, 224 

Solanum melongena, 223 
tuberosum, 92, 223, 224 

Solidago, 109, 282 

Solomon's seal, 68, 105 

Sophora japonica, 237 

Sorbus, 110, 234 

Sorghum, varieties of, 308 

Sorghum grasses, 304, 308 

Sorgo, 308 

Sorrel, 66, 90, 188 

Sour orange, 191 



424 



FLOWERS AND FLOWERING PLANTS 



Soursop, 170 

South Dakota state flower, 175 

Spadix, 107, 112, 295, 296 

Spagel seeds, 214 

Sparganiaceae, 288, 289 

Spafganium, 289 

Spathe, 112, 296 

Spathyema, 34, 107 

Speargrass, 307 

Spearmint, 231 

Species, 1, 136-148, 167 

Specific names, 136-148 

Speedwell, 16 

Spergulaira, 5, 56 

Sperm, 26, 27, 38, 40, 41 

Spice bush, 172 

Spider lily, 311 

Spider plant, 201 

Spiderworts, 7, 66, 91, 292, 293 

Spiderwort family, 292, 293 

Spike, 106, 107 

Spikelets, of grasses, 110, 301, 302, 

304, 305, 307 
Spikenard, 267, 273 
Spinach, 206, 223 
Spinatia, experiments with, 223 

oleracea, 206 
Spmdletrec, 255 
Spines, 136 
Spiraea, 11, 234 
Spiral flowers, 73-75, 152 
Spiranthes, 142 
Spurge, 23, 192, 193 
Spurge family, 192, 193 
Squash, 251 
Squill, 78, 292 
Squirting cucumber, 68 
Stachys, 231 

Stamen, 3, 4, 6, 13, 14, 16, 17, 73, 100 
Standard (in legumes), 15 
Stapelia, 34 

variegata, 221 
Starflower family, 249 

order, 249 

Starflowers, 243, 249 
Star-of-Bethlehem, 292 
State floras, 373 
Statice arrneria, 213 
Stellaria, 204 



Stephanotus, 220 
Stems, 119-125 

aerial, 121 

climbing, 121 

crawling, 121 

creeping, 121 

decumbent, 121 

prostrate, 121 

subterranean, 122 

twining, 122 
Sterculiaceae, 182 
Sterile flowers, 111 

pollen of, 37 
Stigma, 3, 20, 29 
Stipa co mala, 307 

spartea, 307 
Stipules, 126, 126, 136 
St. John's bread, 235 
St. John's wort, 196 
Stokes' aster, 282 
Stoke sia lacins, 282 
Stolon, 70, 71, 121 
Stone, 49, 50 

Stonocrop family, 242, 242 
Storax family, 216 
Strawberry, 45, 49, 51, 52, 71, 76, 

233, 234 

Strelilzia reginar, 315 
Strobila?ithus dcgeriamtSj 229 
Style, 3, 4, 5, 19, 40 
Styracaceae, 216 
Sudan grass, 308 
Sugar beet, 206 

cane, 304, 308 

maple, 161, 261 
Sultan's balsam, 192 
Sumac, 262 
Summary of fruits, 54 
Summer cypress, 206 
Sundew, pistil of, 19 
Sunflower, 43, 44, 45, 69, 109, 277, 
279, 280 

Russian, 25 
Superior ovary, 12, 13, 77, 79, 81, 

86, 99 

Supernumerary buds, J20 
Surface character of leaves, 134, 135 

canescent, 134 

floccose, 134 



INDEX 



425 



Surface character of leaves, gla- 
brate, 134 

glabrous, 134 

glandular, 135 

glaucous, 135 

glutinous, 134 

hirsute, 134 

hispid, 134 

pilose, 134 

puberulent, 134 

pulverulent, 135 

pruinose, 135 

scabrous, 134 

sericeous, 134 

squarrose, 134 

strigose, 134 

verrucose, 134 

villous, 134 
Swamp lily, 311 

milkweed, 220 
Sweet alyssum, 202 

corn, 308 

gum, 241 

Mary, 283 

orange, 191 

pea, 15, 90, 236, 237 

potato, 222 

scabious, 273 

sop, 170 

vernal grass, 306 

William, 76, 96, 110, 221, 271 
Swiss chard, 206 
Sycamore, 109, 241, 242 

American, 241, 241 

European, 241 

London, 241 

Oriental, 241 

Sycamore family, 241, 241, 242 
Syconium, 52, 53, 54 
Symbols used on chart, 94, 159 
Symmetry of flowers, 15, 83, 84, 85 

bilateral, 15, 16, 35-37, 83, 84, 85 

radial, 15, 83 

Sympetalous flowers, 14, 15, 153, 159 
Sympetaly, 14, 80, 92, 98, 153, 159 
Symphoricarpos, 272 
Symplocos, 107 

Svncarpous flowers, 3, 20, 21, 79 r 
153, 159 



Syncarpy, 21, 79, 153, 159 

Synergids, 40, 41 

Synopses, 160, 161 

Synsepalous flowers, 13, 15, 80, 153, 

159 

Synsepaly, 13, 80, 153, 159 
Syringa, 93, 111, 219 

vulgaris, 218 

Systema Naturae of Linnaeus, 325 
Systematic botany, 137 
Systems of classification, 149-160, 
318-353 

artificial, 139 

of Bentharn and Hooker, 335-338 

of Bessey, 346-353 

of de Candolle, 331-333 

of Eichler, 338-339 

of Endhcher, 334-335 

of Kngler, 340-345 

of de Jussieu, 329-331 

of Linnaeus, 324-328 

natural, 139 

phylogenetie, 139, 149-159 



Tamarind, 235 

Tamarindus indica, 235 

Tanacetum vulgare, 283 

Tangerine, 191 

Tansy, 283 

Tap root, 116 

Tapegrass family, 309 

Tapioca, 194 

Taraxacum, 18, 31, 64, 87, 109, 278, 

278, 279 

Taxonomy, 137, 145 
Tea, 19, 195, 196 

Paraguay, 258 
Tea family, 195, 196 
Tea order, 195 
Teak, 230 
Teasel, 43, 81, 273 
Teasel family, 273 
Tecoma, 81 

radicans, 227 
Tectona grandis, 230 
Tendrils, 121, 122, 123, 136 
Teosinte, 308 



426 



FLOWERS AND FLOWERING PLANTS 



Terminal buds, 119, 120, 121 
Testa, 60 
Thalictrum, 111 
Thea, 19, 195, 196 

sinensis, 195 
Tkeaceae, 195, 196 
Theales, 195 
Theobroma, 68 

cacao, 182 

Theophrastus, 318, 319, 320, 323 
Thiorie tUmentaire de la botanique, 

of do Caiidolle, 332 
Thistle, 24, 87, 279, 281 
Thlaspi arvense, 202 
Thorns, 121 
Thyme, 231 
Thymus vulgaris, 231 
Thyrsus, 111 
Ticksccd, 280 
Tiger lily, 292 
Tilia, 17, 181 

americana, 181 

europea, 181 
Tiliaceae, 181, 181 
Tillandsia usneoides, 313 
Timothy, 107, 303, 307, 307 
Tips of leaves, 132, 133 

acuminate, 132, 133 

acute, 132, 133 

aristatc, 133 

cuspidate, 133 

emarginate, 133 

obtuse, 132, 133 

retuse, 133 

truncate, 133 
Toadstools, 2 

Tobacco, 6, 21, 44, 92, 224, 22(4 
Tomato, 50, 224 
Torus, 11 

Touch-me-not, 66, 192 
Tournefort, 324, 324 
Toxylon, 109 

pomiferum, 185 
Trachodendron, 22 
Tradescantia, 7, 66, 91, 293 

reflexa, 293 

virginiana, 293 
Tragopogon porrifolius, 281 
Trailing arbutus, 215 



Trapa natans, 248 
Traveler's tree, 314, 314 
Tree books, 376-378 
Tree cactus, 253 
Tree-of-Heaven, 23, 46, 64 
Tribulus, 64 
Trifoliate orange, 191 
Trifolium, 7, 236 

arvense, 237 

hybridum, 109 

pratense, 237 
Triple-awned grass, 64 
Trisetum spicatum, 305 
Triticum, 6, 30, 110, 141, 208, 305 

polonicum, 305 

sativurn, 305 

turgidum, 305 
Trollius, 175 
Tropaeolum, 33, 35, 84 
Trowels, 357-358 
Trumpet flower, 81, 227 

narcissus, 311 

vine, 227 

Tube of corolla, 14, 15, 81, 84 
Tube nucleus, 38, 40, 41 
Tubers, 69, 136 

Tubular flowers, 14, 15, 76, 81, 84 
Tulip, 78, 79, 292 
Tulip tree, 76, 170 
Tulipa, 78, 79, 292 
Tumbleweeds, 67 
Turnip, 202 
Twin flower, .272, 272 
Twiners, 121, 122 
Typha, 289 
Typhaceae, 102, 289, 290 

U 

Ulmaceae, 183, 183 

Ulmus, 22, 30, 46, 142, 183, 184 

americana, 183, 184 

campestriSj 184 

futoa, 183, 184 

scabra, 184 
Umbel, 107, 108 
Umbellales, 266 

Umbdliferae, 99, 102, 108, 110, 268, 
269 



INDEX 



427 



Umbellularia calif ornica, 172 

Umbrella plant, 300 

Unicorn plant, 48 

Union, of carpels, 20, 21, 79, 153 

of different floral whorls, 82 

of floral elements, 14, 15 

of petals, 14, 15, 80, 152-155 

of sepals, 14, 80, 153 

of stameqs, 17, 80, 82, 93 
Urlica, 22, 30, 110, 186 

dioica, 186 

romana, experiments with sex of, 

323 

Urticaceae, 186, 186 
Urticastrum, 30 
Utriatlaria, 92, 229 



Vacdnium, 4, 214, 215 
Vagnera slellata, 105 
Valerian, 22, 273 
Valerian family, 272, 273 
Valeriana, 16, 64, 272, 273 

officinalis, 273 
Valerianaceae, 272, 273 
Valerianella ohloria, 273 
Valhsneria spiralis, 29 
Vallisneriaceae, 309 
Vanilla, 317 

plani folia, 317 

pompona, 317 
Vanilla extract, 317 
Vanilla grass, 306 
Varieties of maize, 308 
Vasculum, 344, 356 
Vegetable ivory, 56, 59 

marrow, 251 

oyster, 281 

sheep, 283 

sponge, 252 

Vegetative characters, 114-136 
Velocity of migration, 72 
Venation, types of, 128, 129 
Ventilators for plant press, 363 
Verbascum, 106 
Verbena, 107, 230 
Verbenaceae, 229, 230 
Vernal grass, 306 



Vernation, types of, 127 
Vernonia, 142, 282 
Vernonieae, 279, 282 
Veronica, 16, 64 
Verticillate leaves, 126 
Vervain, 107 
Vetch, 66 

Viburnum, 110, 272 
Victoria regia, 176 
Vinca, 220, 219 

minor, 219 
Viola, 35, 66, 153, 197 

odorata, 197 

tricolor, 197 
Violaceae, 197 
Violet, 35, 66, 197, 197 
Violet family, 197, 197 
Virginia creeper, 110, 256 
Virgin's bower, 75, 1 75 
Viscum album, 260 
Vitaceae, 255, 256 
Vitis labrusca, 256 

vinifera, 256 

W 

Wahoo, 266 

Wallflower, 4, 91, 202 

Walnut, 6, 22, 23, 46, 50, 66, 65, 106 

black, 263, 264 

Circassian, 264 

English, 264 

Persian, 264 

white, 263, 264 
Wandering Jew, 293 
Water hyacinth, 294 
Water plantain, 16, 43, 89, 101, 286, 

287 

Water thyme, 310 
Water weeds, 309 
Water-chestnut. 248 
Watercress, 202 
Waterlcaf family, 223 
Waterlily, 44, 75, 176 
Waterlily family, 175, 176 
Watermelon, 251, 252 
Watershield, 176 
Waxwort, 255 
Weeping willow, 210 



428 



FLOWERS AND FLOWERING PLANTS 



West Indian locust, 235 
Western mustard, 202 
Wettstein, 154 

Wheat, 30, 43, 107, 110, 302, 305 
White elm, 183, 184 

oak, 264 

pine, 122 

snakeroot, 282 

walnut, 264 

weed, 280 

willow, 210 

wood, 170 

Whorled leaves, 126 
Wild barley, 302 

oat, 305 

pea, 69 

rice, 7, 23, 153, 306 

sarsaparilla, 267 
Willow, 4, 30, 63, 106, 209, 210 

basket, 210 

peach-leaved, 209 

sandbar, 209 

weeping, 210 

white, 210 

yellow, 210 

Willow family, 209, 210 
Willowherb, 63, 247 
Wind, as agent of migration, 63 

as pollinating agent, 30 
Windflowers, 75, 175 
Wind-pollinated flowers, 31 
Wings, 15, 84, 236, 236 
Winter annuals, 118 
Winter wheat, 118 
Wintercress, 202 
Wintergreen, 17, 214, 215 
Wire grass, 116 
Wisteria, 237 
Wisteria sinensis, 237 
Witchhazel, 66, 240, 241 

extract of, 241 
Witchhazel family, 240, 241 
Woody roots, 116 
Woody types, 150, 151 



Xanthium, 280 
Xenogamy, 28 



Yams, 315 
Yarrow, 283 
Yellow pine, 117 

poplar, 170 

willow, 210 
Yucca, 105, 106, 291 

gloriosa, 105, 106 

Z 

Zannichelliaceae, 288, 288 

Zea, experiments with SPX of, 323 

Zea mays, 308 

varieties of, 308 
Zebra corn, 308 
Zebra grass, 308 
Zebrina pendula, 29$ 
Zingiber officinale, 315 
Zingiberaceae, 315 
Zinnia, 280 

Zizania aquatica, 153, 306 
Zizyphus jujuba, 257 
Zostera, 29 

Zygocactus truncatus, 253 
Zygomorphy, 15, 16, 35-38, 83-85, 
153, 159 

in composites, 275, 277, 278 

in legumes, 235, 236 

in mints, 16, 84, 230, 231 

in orchids, 85, 316 

in slipperworts, 85 

in snapdragons, 16, 85, 226 

in violets, 36, 84, 197 
and relationship, 85, 153, 159 
Zygote, 26