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GRAY'S LESSONS IN BOTANY
REVISED EDITION
THE
ELEMENTS OF BOTANY
FOR BEGINNERS AND FOR SCHOOLS
By ASA GRAY
IVISON, BLAKEMAN, AND COMPANY
NEW YORK AND CHICAGO
_Copyright_,
By Asa Gray.
1887.
PREFACE.
This volume takes the place of the author's Lessons in Botany and
Vegetable Physiology, published over a quarter of a century ago. It is
constructed on the same lines, and is a kind of new and much revised
edition of that successful work. While in some respects more extended,
it is also more concise and terse than its predecessor. This should the
better fit it for its purpose now that competent teachers are common.
They may in many cases develop paragraphs into lectures, and fully
illustrate points which are barely, but it is hoped clearly, stated.
Indeed, even for those without a teacher, it may be that a condensed is
better than a diffuse exposition.
The book is adapted to the higher schools, "How Plants Grow and Behave"
being the "Botany for Young People and Common Schools." It is intended
to ground beginners in Structural Botany and the principles of vegetable
life, mainly as concerns Flowering or Phanerogamous plants, with which
botanical instruction should always begin; also to be a companion and
interpreter to the Manuals and Floras by which the student threads his
flowery way to a clear knowledge of the surrounding vegetable creation.
Such a book, like a grammar, must needs abound in technical words, which
thus arrayed may seem formidable; nevertheless, if rightly apprehended,
this treatise should teach that the study of botany is not the learning
of names and terms, but the acquisition of knowledge and ideas. No
effort should be made to commit technical terms to memory. Any term used
in describing a plant or explaining its structure can be looked up when
it is wanted, and that should suffice. On the other hand, plans of
structure, types, adaptations, and modifications, once understood, are
not readily forgotten; and they give meaning and interest to the
technical terms used in explaining them.
In these "Elements" naturally no mention has been made of certain terms
and names which recent cryptogamically-minded botanists, with lack of
proportion and just perspective, are endeavoring to introduce into
phanerogamous botany, and which are not needed nor appropriate, even in
more advanced works, for the adequate recognition of the ascertained
analogies and homologies.
As this volume will be the grammar and dictionary to more than one or
two Manuals, Floras, etc., the particular directions for procedure which
were given in the "First Lessons" are now relegated to those works
themselves, which in their new editions will provide the requisite
explanations. On the other hand, in view of such extended use, the
Glossary at the end of this book has been considerably enlarged. It will
be found to include not merely the common terms of botanical description
but also many which are unusual or obsolete; yet any of them may now and
then be encountered. Moreover, no small number of the Latin and Greek
words which form the whole or part of the commoner specific names are
added to this Glossary, some in an Anglicized, others in their Latin
form. This may be helpful to students with small Latin and less Greek,
in catching the meaning of a botanical name or term.
The illustrations in this volume are largely increased in number. They
are mostly from the hand of Isaac Sprague.
It happens that the title chosen for this book is that of the author's
earliest publication, in the year 1836, of which copies are rarely seen;
so that no inconvenience is likely to arise from the present use of the
name.
ASA GRAY.
Cambridge, Massachusetts,
_March, 1887_.
CONTENTS.
Page
SECTION I. INTRODUCTORY 9
SECTION II. FLAX AS A PATTERN PLANT 11
Growth from the Seed, Organs of Vegetation 11
Blossoming, Flower, &c. 14
SECTION III. MORPHOLOGY OF SEEDLINGS 15
Germinating Maples 15
Cotyledons thickened, hypogaeous in germination 18
Store of Food external to the Embryo 20
Cotyledons as to number 22
Dicotyledonous and Polycotyledonous 23
Monocotyledonous 24
Simple-stemmed Plants 26
SECTION IV. GROWTH FROM BUDS; BRANCHING 27
Buds, situation and kinds 27
Vigorous vegetation from strong Buds 28
Arrangement of Branches 29
Non-developed, Latent, and Accessory Buds 30
Enumeration of kinds of Buds 31
Definite and Indefinite growth; Deliquescent and Excurrent 31
SECTION V. ROOTS 33
Primary and Secondary. Contrast between Stem and Root 34
Fibrous and Fleshy Roots; names of kinds 34
Anomalous Roots. Epiphytic and Parasitic Plants 36
Duration: Annuals, Biennials, Perennials 37
SECTION VI. STEMS 38
Those above Ground: kinds and modifications 39
Subterranean Stems and Branches 42
Rootstock 42
Tuber 44
Corm 45
Bulb and Bulblets 46
Consolidated Vegetation 47
SECTION VII. LEAVES 49
Sec. 1. LEAVES AS FOLIAGE 49
Parts and Venation 50
Forms as to general outline 52
As to apex and particular outline 53
As to lobing or division 56
Compound, Perfoliate, and Equitant Leaves 57
With no distinction of Petiole and Blade, Phyllodia, &c. 61
Sec. 2. LEAVES OF SPECIAL CONFORMATION AND USE 62
Leaves for storage 62
Leaves as bud-scales 63
Spines 64
and for Climbing 64
Pitchers 64
and Fly-traps 65
Sec. 3. STIPULES 66
Sec. 4. THE ARRANGEMENT OF LEAVES 67
Phyllotaxy 67
Of Alternate Leaves 69
Of Opposite and Whorled Leaves 71
Vernation or Praefoliation 71
SECTION VIII. FLOWERS 72
Sec. 1. POSITION AND ARRANGEMENT, INFLORESCENCE 73
Raceme 73
Corymb, Umbel, Spike, Head 74
Spadix, Catkin, or Ament 75
Panicle: Determinate Inflorescence 76
Cyme, Fascicle, Glomerule, Scorpioid or Helicoid Cymes 77
Mixed Inflorescence 78
Sec. 2. PARTS OR ORGANS OF THE FLOWER 79
Floral Envelopes: Perianth, Calyx, Corolla 79
Essential Organs: Stamen, Pistil 80
Torus or Receptacle 81
Sec. 3. PLAN OF THE FLOWER 81
When perfect, complete, regular, or symmetrical 81
Numerical Plan and Alternation of Organs 82
Flowers are altered branches 83
Sec. 4. MODIFICATIONS OF THE TYPE 85
Unisexual or diclinous 85
Incomplete, Irregular, and Unsymmetrical 86
Flowers with Multiplication of Parts 88
Flowers with Union of Parts: Coalescence 88
Regular Forms 89
Irregular Forms 90
Papilionaceous 91
Labiate 92
and Ligulate Corollas 93
Adnation or Consolidation 94
Position of Flower or of its Parts 96
Sec. 5. ARRANGEMENT OF PARTS IN THE BUD 97
AEstivation or Praefloration, its kinds 97
SECTION IX. STAMENS IN PARTICULAR 98
Androecium 98
Insertion, Relation, &c. 99
Anther and Filament. Pollen 101
SECTION X. PISTILS IN PARTICULAR 105
Sec. 1. ANGIOSPERMOUS OR ORDINARY GYNOECIUM 105
Parts of a complete Pistil 105
Carpels, Simple Pistil 106
Compound Pistil with Cells and Axile Placentae 107
One-celled with Free Central Placenta 108
One-celled with Parietal Placentae 108
Sec. 2. GYMNOSPERMOUS GYNOECIUM 109
SECTION XI. OVULES 110
Their Parts, Insertion, and Kinds 111
SECTION XII. MODIFICATIONS OF THE RECEPTACLE 112
Torus, Stipe, Carpophore, Disk 113
SECTION XIII. FERTILIZATION 114
Sec. 1. ADAPTATIONS FOR POLLINATION OF THE STIGMA 114
Close and Cross Fertilization, Anemophilous and Entomophilous 115
Dichogamy and Heterogony 116
Sec. 2. ACTION OF THE POLLEN AND FORMATION OF THE EMBRYO 117
SECTION XIV. THE FRUIT 117
Nature and kinds 118
Berry, Pepo, Pome 119
Drupe and Akene 120
Cremocarp, Caryopsis, Nut 121
Follicle, Legume, Capsule 122
Capsular Dehiscence, Silique and Silicle 123
Pyxis, Strobile or Cone 124
SECTION XV. THE SEED 125
Seed-coats and their appendages 125
The Kernel or Nucleus, Embryo and its parts, Albumen 127
SECTION XVI. VEGETABLE LIFE AND WORK 128
Sec. 1. ANATOMICAL STRUCTURE AND GROWTH 129
Nature of Growth, Protoplasm 129
Cells and Cell-walls. Cellular Structure or Tissue 130
Strengthening Cells. Wood, Wood-cells, Vessels or Ducts 132
Sec. 2. CELL-CONTENTS 136
Sap, Chlorophyll, Starch 136
Crystals, Rhaphides 137
Sec. 3. ANATOMY OF ROOTS AND STEMS 138
Endogenous and Exogenous Stems 139
Particular structure of the latter 140
Wood, Sapwood and Heart-wood. The living parts of a Tree 141
Sec. 4. ANATOMY OF LEAVES 142
Epidermis, Stomata or Breathing pores 143
Sec. 5. PLANT FOOD AND ASSIMILATION 144
Sec. 6. PLANT WORK AND MOVEMENT 149
Movements in Cells or Cyclosis 149
Transference from Cell to Cell 150
Movements of Organs, Twining Stems, Leaf-movements 150
Movements of Tendrils, Sensitiveness 152
Movements in Flowers 153
Movements for capture of Insects 154
Work costs, using up Material and Energy 155
SECTION XVII. CRYPTOGAMOUS OR FLOWERLESS PLANTS 156
Vascular Cryptogams, Pteridophytes 156
Horsetails (Equisetaceae), Ferns 157
Club-Mosses (Lycopodium), &c. 161
Quillworts (Isoetes), Pillworts (Marsilia) 161
Azolla. Cellular Cryptogams 162
Bryophytes. Mosses (Musci) 163
Liverworts (Hepaticae) 164
Thallophytes 165
Characeae 167
Algae, Seaweeds, &c. 168
Lichenes or Lichens 171
Fungi 172
SECTION XVIII. CLASSIFICATION AND NOMENCLATURE 175
Sec. 1. KINDS AND RELATIONSHIP 175
Species, Varieties, Individuals 176
Genera, Orders, Classes, &c. 177
Sec. 2. NAMES, TERMS AND CHARACTERS 178
Nomenclature of Genera, Species, and Varieties 179
Nomenclature of Orders, Classes, &c. Terminology 180
Sec. 3. SYSTEM 181
Artificial and Natural 182
Synopsis of Series, Classes, &c. 183
SECTION XIX. BOTANICAL WORK 184
Sec. 1. COLLECTION OR HERBORIZATION 184
Sec. 2. HERBARIUM 186
Sec. 3. INVESTIGATION AND DETERMINATION OF PLANTS 187
Sec. 4. SIGNS AND ABBREVIATIONS 188
ABBREVIATIONS OF THE NAMES OF BOTANISTS 190
GLOSSARY COMBINED WITH INDEX 193
ELEMENTS OF BOTANY.
Section I. INTRODUCTORY.
1. BOTANY is the name of the science of the vegetable kingdom in
general; that is, of plants.
2. Plants may be studied as to their kinds and relationships. This study
is SYSTEMATIC BOTANY. An enumeration of the kinds of vegetables, as far
as known, classified according to their various degrees of resemblance
or difference, constitutes a general _System of plants_. A similar
account of the vegetables of any particular country or district is
called a _Flora_.
3. Plants may be studied as to their structure and parts. This is
STRUCTURAL BOTANY, or ORGANOGRAPHY. The study of the organs or parts of
plants in regard to the different forms and different uses which the
same kind of organ may assume,--the comparison, for instance, of a
flower-leaf or a bud-scale with a common leaf,--is VEGETABLE MORPHOLOGY,
or MORPHOLOGICAL BOTANY. The study of the minute structure of the parts,
to learn by the microscope what they themselves are formed of, is
VEGETABLE ANATOMY, or HISTOLOGY; in other words, it is Microscopical
Structural Botany. The study of the actions of plants or of their parts,
of the ways in which a plant lives, grows, and acts, is the province of
PHYSIOLOGICAL BOTANY, or VEGETABLE PHYSIOLOGY.
4. This book is to teach the outlines of Structural Botany and of the
simpler parts of the physiology of plants, that it may be known how
plants are constructed and adapted to their surroundings, and how they
live, move, propagate, and have their being in an existence no less
real, although more simple, than that of the animal creation which they
support. Particularly, this book is to teach the principles of the
structure and relationships of plants, the nature and names of their
parts and their modifications, and so to prepare for the study of
Systematic Botany; in which the learner may ascertain the name and the
place in the system of any or all of the ordinary plants within reach,
whether wild or cultivated. And in ascertaining the name of any plant,
the student, if rightly taught, will come to know all about its general
or particular structure, rank, and relationship to other plants.
5. The vegetable kingdom is so vast and various, and the difference is
so wide between ordinary trees, shrubs, and herbs on the one hand, and
mosses, moulds, and such like on the other, that it is hardly possible
to frame an intelligible account of plants as a whole without
contradictions or misstatements, or endless and troublesome
qualifications. If we say that plants come from seeds, bear flowers, and
have roots, stems, and leaves, this is not true of the lower orders. It
is best for the beginner, therefore, to treat of the higher orders of
plants by themselves, without particular reference to the lower.
6. Let it be understood, accordingly, that there is a higher and a lower
series of plants; namely:--
PHANEROGAMOUS PLANTS, which come from seed and bear _flowers_,
essentially stamens and pistils, through the co-operation of which seed
is produced. For shortness, these are commonly called PHANEROGAMS, or
_Phaenogams_, or by the equivalent English name of FLOWERING PLANTS.[1]
CRYPTOGAMOUS PLANTS, or CRYPTOGAMS, come from minute bodies, which
answer to seeds, but are of much simpler structure, and such plants have
not stamens and pistils. Therefore they are called in English FLOWERLESS
PLANTS. Such are Ferns, Mosses, Algae or Seaweeds, Fungi, etc. These
sorts have each to be studied separately, for each class or order has a
plan of its own.
7. But Phanerogamous, or Flowering, Plants are all constructed on one
plan, or _type_. That is, taking almost any ordinary herb, shrub, or
tree for a pattern, it will exemplify the whole series: the parts of one
plant answer to the parts of any other, with only certain differences in
particulars. And the occupation and the delight of the scientific
botanist is in tracing out this common plan, in detecting the likenesses
under all the diversities, and in noting the meaning of these manifold
diversities. So the attentive study of any one plant, from its growth
out of the seed to the flowering and fruiting state and the production
of seed like to that from which the plant grew, would not only give a
correct general idea of the structure, growth, and characteristics of
Flowering Plants in general, but also serve as a pattern or standard of
comparison. Some plants will serve this purpose of a pattern much better
than others. A proper pattern will be one that is perfect in the sense
of having all the principal parts of a phanerogamous plant, and simple
and regular in having these parts free from complications or disguises.
The common Flax-plant may very well serve this purpose. Being an annual,
it has the advantage of being easily raised and carried in a short time
through its circle of existence, from seedling to fruit and seed.
FOOTNOTES:
[1] The name is sometimes _Phanerogamous_, sometimes _Phaenogamous_
(_Phanerogams_, or _Phaenogams_), terms of the same meaning
etymologically; the former of preferable form, but the latter shorter.
The meaning of such terms is explained in the Glossary.