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C- 71
GRAY'S *
SCHOOL AND FIELD BOOK
OP
BOTANY.
CONSISTING OP
"LESSONS IN BOTANY," AND "FIELD, FOREST, AND
GARDEN BOTANY,"
BOUND IN ONE VOLUME.
BY ASA GRAY,
KSHER PROFESSOR OP NATURAL HISTORY IN HARVARD
IVISON, BLAKEMAN, TAYLOR & CO.,
NEW YORK AND CHICAGO.
1881.
PUBLISHEES' PREFACE
GHAT'S SCHOOL AND FIELD BOOK OF BOTANY
THIS work consists of the " LESSONS IN BOTANY " and the
" FIELD, FOREST AND GARDEN BOTANY," bound together in one
complete volume, forming a most popular and comprehensive
SCHOOL BOTANY, adapted to beginners and advanced classes, to
Agricultural Colleges and Schools, as well as to all other grades
in which the science is taught ; it is also adapted for use as a
hand-book to assist in analyzing plants and flowers in field
study of botany, either by classes or individuals.
The book is intended to furnish Botanical Classes and
beginners with an easier introduction to the Plants of this
country, and a much more comprehensive work, than is tne
MANUAL.
Beginning with the first principles, it progresses by easy
stages until the student, who is at all diligent, is enabled to
master the intricacies of the science.
It is a Grammar and Dictionary of Botany, and comprises
the common Herbs, Shrubs, and Trees of the Southern as well
as the Northern and Middle States, including the commonly
cultivated, as well as the native species in fields, gardens,
pleasure-grounds, or house culture, and even the conservatory
plants ordinarily met with.
This work supplies a great desideratum to the Botanist and
Botanical Teacher, there being no similar class-book published
in this country.
GRAY'S 3
LESSONS IN BOTANY
AND
VEGETABLE PHYSIOLOGY,
ILLUSTRATED BY OVER 360 WOOD ENGRAVINGS, FROM ORIGINAL
DRAWINGS, BY ISAAC SPRAGUE.
TO WHICH IS ADDED A COPIOUS
GLOSSARY,
OB
DICTIONARY OF BOTANICAL TERMS,
BY ASA GKAY,
FISHER PROFESSOR OP NATURAL HISTORY IN HARVARD UNIVERSITY.
IVISON, BLAKEMAN, TAYLOR & CO.,
NEW YORK AND CHICAGO
1881.
Entered according to Act of Congress, In the year 1357, by
GEORGE T. PUTNAM & i-i- .
the Clerk's Office of the District Court for the Southern District of New Yon.
Entered according to Act of Congress, in ft- 3 /ear 1868, bv
ASA GRAY,
In the Clerk's Office of the District Court for the District of Massachusetts.
PREFACE.
THIS book is intended for the use of beginners, and for classes in the
common and higher schools, in which the elements of Botany, one of
the most generally interesting of the Natural Sciences, surely ought to be
taught, and to be taught correctly, as far as the instruction proceeds.
While these Lessons are made as plain and simple as they well can be,
all the subjects treated of have been carried far enough to make the book
a genuine Grammar of Botany and Vegetable Physiology, and a sufficient
introduction to those works in which the plants of a country especially
of our own are described.
Accordingly, as respects the principles of Botany (including Vege-
table Physiology), this work is complete in itself, as a school-book
for younger classes, and even for the students of our higher seminaries.
For it comprises a pretty full account of the structure, organs, growth,
and reproduction of plants, and of their important uses in the scheme of
creation, subjects which certainly ought to be as generally understood
by all educated people as the elements of Natural Philosophy or Astron-
omy are ; and which are quite as easy to be learned.
The book is also intended to serve as an introduction to the author's
Manual of the Botany of the Northern United States (or to any similar
work describing the plants of other districts), and to be to it what a
grammar and a dictionary are to a Classical author. It consequently con -
tains many terms and details which there is no necessity for young stu-
dents perfectly to understand in the first instance, and still less to commit
to memory, but which they will need to refer to as occasions arise, when
they come to analyze flowers, and ascertain the names of our wild plants.
To make the book complete in this respect, a full Glossary, or Diction-
ary of Terms used in describing Plants, is added to the volume. This con-
tains very many words which are not used in the Manual of Botany;
but as they occur in common botanical works, it was thought best to in-
troduce and explain them. All the words in the Glossary which seemed
to require it are accented.
IT PREFACE.
It is by no means indispensable for students to go through the volume
before commencing with the analysis of plants. When the proper season
for botanizing arrives, and when the first twelve Lessons have been gone
over, they may take up Lesson XXVIII. and the following ones, and pro-
ceed to study the various wild plants they find in blossom, in the manner
illustrated in Lesson XXX., &e., referring to the Glossary, and thence
to the pages of the Lessons, as directed, for explanations of the various
distinctions and terms they meet with. Their first ^essays will necessarily
be rather tedious, if not difficult ; but each successful attempt smooths
the way for the next, and soon these technical terms and distinctions
will become nearly as familiar as those of ordinary language.
Students who, having mastered this elementary work, wish to extend
their acquaintance with Vegetable Anatomy and Physiology, and to con-
sider higher questions about the structure and classification of plants, will
be prepared to take up the author's Botanical Text-Book, an Introduction
to Structural Botany, or other more detailed treatises.
No care and expense have been spared upon the illustrations of this
volume; which, with one or two exceptions, are all original. They
were drawn from nature by Mr. Sprague, the most accurate of living
botanical artists, and have been as freely introduced as the size to which
it was needful to restrict the volume would warrant.
To append a set of questions to the foot of each page, although not un-
usual in school : books, seems like a reflection upon the competency or the
faithfulness of teachers, who surely ought to have mastered the lesson be-
fore they undertake to teach it; nor ought facilities to be afforded for
teaching, any more than learning, lessons by rote. A full analysis of the
contents of the Lessons, however, is very convenient and advantageous.
Such an Analysis is here given, in place of the ordinary table of con-
tents. This will direct the teacher and the learner at once to the leading
ideas and important points of each Lesson, and serve as a basis to ground
proper questions on, if such should be needed.
ASA GRAY.
HARVARD UNIVERSITY, CAMBRIDGE,
January 1, 1857.
%* Revised August, 1868, and alterations made adapting it to the new edition of
Manual, and to Fitld, Forest, and Garden tiotany, to which this work is the propel
introduction and companion.
A. G.
ANALYSIS OF THE LESSONS. 1
LESSON I. BOTANY AS A BRANCH OF NATURAL HISTORY. . . p. 1.
1. Natural History, its subjects. 2. The Inorganic or Mineral Kingdom,
what it is : why culled Inorganic. 3. The Organic world, or the world of Or-
ganized beings, why so called, and what its peculiarities. 4. What kingdoms
it comprises. 5, 6. Differences between plants and animals. 7. The use of
plants : how vegetables are nourished ; and ho\v animals.
8. Botany, how defined. 9. Physiology, and Physiological Botany, what
/iey relate to. 10. Systematic Botany, what it relates to : a Flora, what it is.
11. Geographical Botany, Fossil Botany, c., what they relate to.
LESSON II. THE GROWTH OF THE PLANT FROM THE SEED. . p. 4.
12. The Course of Vegetation : general questions proposed. 13. Plants
formed on one general plan. 14. The Germinating Plantlet : 15. exists in
miniature in the seed: 16. The Embryo; its parts: 17, 18. how it develops.
19. Opposite growth of Root and Stem : 20. its object or results : 21,22. the
different way each grows.
LESSON III. GROWTH OF THE PLANT FROM THE SEED ; continued, p. 9.
23. Recapitulation : Ascending and Descending Axis. 24, 25. The Germi-
nating Plantlet, how nourished. 26. Deposit of food in the embryo, illustrated
in the Squash, c. : 27. in the Almond, Apple-seed, Beech, &c. : 28. in the
Bean : 29. in the Pea, Oak, and Buckeye : peculiarity of these last. 30, 31.
Deposit of food outside of the embryo : Albumen of the seed : various shapes
of embryo. 32, 33. Kinds of embryo as to the number of Cotyledons : di-
cotyledonous : monocotyledonous : polycotyledonous. 34, 35. Plan of vegeta
tion. 36. Simple-stemmed vegetation illustrated.
LESSON IV. THE GROWTH OF PLANTS FROM BUDS AND BRANCHES, p. 20.
37, 38. Branching : difference in this respect between roots and stems. 39.
Buds, what they are, and where situated : 40. how they grow, and what they
become. 41. Plants as to size and duration : herb, annual, biennial, perennial:
shrub : tree. 42. Terminal Bud. 43. Axillary Buds. 44. Scaly Buds. 45.
Naked Buds. 46. Vigor of vegetation from buds illustrated. 47-49. Plan
and arrangement of Branches : opposite : alternate. 50. Symmetry of Branches,
* The numbers in the analysis refer to the paragraphs.
Vi ANALYSIS OF THE LESSONS.
what it depends on: 51. how It becomes incomplete: 51-59. how varied.
53. Definite growth. 54. Indefinite growth. 55. Deliquescent or dissolving
stems, how formed. 56. Excurrent stems of spire-shaped trees, how produced.
57. Latent Buds. 58. Adventitious Buds. 59. Accessory or supernumerary
Buds. 60. Sorts of Buds recapitulated and defined.
LESSON V. MORPHOLOGY OF ROOTS p. 28.
61 - 64. Morphology; what the term means, and how applied in Botany. 65.
Primary Root, simple ; and, 66. multiple. 67. Rootlets ; how roots absorb :
time for transplantation, &c. 68. Great amount of surface which a plant
spreads out, in the air and in the soil ; reduced in winter, increased in spring.
69. Absorbing surface of roots increased by the root-hairs. 70. Fibrous roots
for absorption. 71. Thickened or fleshy roots as storehouse of food. 72, 73.
Their principal fv>"ins. 74. Biennial roots ; their economy. 75. Perennial
thickened roots. 76. Potatoes, &c. are not roots. 77. Secondary Roots, their
economy. 78. Sometimes striking in open air, when they are, 79- Aerial Roots ;
illustrated in Indian Corn, Mangrove, Screw Pine, Banyan, &c. 80. Aerial
Rootlets of Ivy. 81. Epiphytes or Air-Plants, illustrated. 82. Parasitic Plants,
illustrated by the Mistletoe, Dodder, &c.
LESSON VI. MORPHOLOGY OF STEMS A-ND BRANCHES. ... p. 36.
83 - 85. Forms of stems and branches above ground. 86. Their direction or
habit of growth. 87. Culm, Caudex, c. 88. Suckers : propagation of plants
by division. 89. Stolons : propagation by layering or laying. 90. Offsets.
91. Runners. 92. Tendrils; how plants climb by them : their disk-like tips in
the Virginia Creeper. 93. Tendrils are sometimes forms of leaves. 94. Spines
or Thorns ; their nature : Prickles. 95. Strange forms of stems. 96. Subter-
ranean stems and branches. 97. The Rootstock or Rhizoma, why stem and
not root. 98. Why running rootstocks are so troublesome, and so hard to de-
stroy. 99-101. Thickened rootstocks, as depositories of food. 102. Their
life and growth. 103. The Tuber. 104. Economy of the Potato-plant. 105.
Gradations of tubers into, 106. Corms or solid bulbs : the nature and economy
of these, as in Crocus. 107. Gradation of these into, 108. the Bulb : nature of
bulbs. 109, 110. Their economy. 111. Their two principal sorts. 112. Bulb-
lets. 113. How the foregoing sorts of stems illustrate what is meant by mor-
phology. 114. They are imitated in some plants above ground. 115. Consoli-
dated forms of vegetation, illustrated by Cactuses, &c. 116. Their economy
and adaptation to dry regions.
LESSON VH. MORPHOLOGY OF LEAVES. . . ^ p. 49.
117. Remarkable states of leaves already noticed. 118, 119. Foliage the
natural form of leaves : others are special forms, or transformations ; why so
called. 120. Leaves as depositories of food, especially the seed-leaves ; and, 121.
As Bulb-scales. 122. Leaves as Bud-scales. 123. As Spines. 124. As Ten-
drils. 125. As Pitchers. 126. As Fly-traps. 127-129. The same leaf serving
various purposes.
ANALYSIS OF THE LESSONS. VH
LESSON VIII. MORPHOLOGY OF LEAVES AS FOLIAGE. ... p. 54.
130. Foliage the natural state of leaves. 131. Leaves a contrivance for in-
creasing surface: the vast surface of a tree in leaf. 132, 133. The parts of a
leaf. 134. The blade. 135. Its pulp or soft part and its framework. 136.
The latter is wood, and forms the rihs or veins and veinlets. 137. Division and
use of these. 138. Venation, or mode of veining. 139. Its two kinds. 140.
Netted-vcined or reticulated. 141. Parallel-veined or nerved. 142. The so-
called veins and nerves essentially the same thing; the latter not like the
nerves of animals. 143. How the sort of veining of leaves answers to the num-
ber of cotyledons and the kind of plant. 144. Two kinds of parallel-veined leaves.
145, 146. Two kinds of netted-veined leaves. 147. Relation of the veining to
the shape of the leaf. 148-151. Forms of leaves illustrated, as to general out-
line. 152. As to the base. 153. As to the apex.
LESSON IX. MORPHOLOGY OF LEAVES AS FOLIAGE ; continued, p. 61.
154, 155. Leaves either simple or compound. 156-162. Simple leaves il-
lustrated as to particular outline, or kind and degree of division. 163. Com-
pound leaves. 164. Leaflets. 165. Kinds of compound leaves. 166, 167.
The pinnate, and, 168. the palmate or digitate. 169. As to number of leaflets,
c. 170. Leaflets, as to lobing, &c. 171, 172. Doubly or trebly compound
leaves of both sorts. 173. Peculiar forms of leaves explained, such as: 174.
Perfoliate: 175. Equitant: 176. Those without blade. 177. Phyllodia, or
flattened petioles. 178. Stipules. 179. Sheaths of Grasses ; Ligule.
LESSON X. THE ARRANGEMENT OF LEAVES p. 71.
181. Phyllotaxy, or arrangement of leaves on the stem : general sorts of ar-
rangement. 182. Leaves arise only one from the same place. 183. Clustered
or fascicled leaves explained. 184. Spiral arrangement of alternate leaves. 185.
The two-ranked arrangement. 186. The three-ranked arrangement. 187. The
five-ranked arrangement. 188. The fractions by which these are expressed.
189. The eight-ranked and the thirteen-ranked arrangements. 190. The series
of these fractions, and their relations. 191. Opposite and whorled leaves.
192. Symmetry of leaves, c. fixed by mathematical rule. 193. Vernation, or
arrangement of leaves in the bud. 194. The principal modes.
LESSON XI. THE ARRANGEMENT OF FLOWERS ON THE STEM,
OR INFLORESCENCE p. 76.
195. Passage from the Organs of Vegetation to those of Fructification or Re-
production. 196. Inflorescence : the arrangement of flowers depends on that
of the leaves. 197. They arc from either terminal or axillary buds. 198. In-
determinate Inflorescence. 199. Its sorts of flower-clusters. 200. Flower-
stalks, viz. peduncles and pedicels, bracts and bractlets, c. 201. Raceme.
202. Its gradation into (203) a Corymb, and that (204) into (205) an Umbel.
206. Centripetal order of development 207. The Spike. 208. The Hea'
fiii ANALYSIS OF THE LESSONS.
209. Spadix. 210. Catkin or Ament. 211, 212. Compound inflorescence of
the preceding kinds. 213. Panicle. 214. Thyrsus. 215. Determinate In-
florescence explained. 216, 217. Cyme: centrifugal order of development
218. Fascicle. 219. Glomerule. 221. Analysis of flower-clusters. 222. Com.
bination of the two kinds of inflorescence in the same plant.
LESSON XII. THE FLOWER : ITS PARTS OR ORGANS p. 84.
223. The Flower. 224. Its nature and use. 225. Its organs. 226. The
Floral Envelopes or leaves of the flower. Calyx and Corolla, together called
(-2-27) Perianth. 228. Petals, Sepals. 229 Neutral and "double" flowers,
those destitute of, 230. The Essential Organs : Stamens and Pistils. 231,232.
The parts of the flower in their si:< cession. 233. The Stamen : its parts. 234.
The Pistil : its parts.
LESSON XIII. THE PLAN OF THE FLOWER p. 88.
235. Flowers all constructed upm the same plan. 236. Plan in vegetation
referred to. 237 - 239. Typical or pattern flowers illustrated, those at once
perfect, complete, regular, and symmetrical. 241 . Imperfect or separated flowers.
242. Incomplete flowers. 243. Symmetry and regularity. 244. Irregular flow-
ers. 245. Unsymmetrical flowers. 246. Numerical plan of the flower. 247.
Alternation of the successive parts. 248. Occasional obliteration of certain parts.
24^- Abortive organs. 250. Multiplication of parts.
LESSON XIV. MORPHOLOGY OF THE FLOWER p 96.
251. Recapitulation of the varied forms under which stems and leaves appear.
252. These may be called metamorphoses. 253. Flowers are altered branches ;
how shown. 254. Their position the same as that occupied by buds. 255,
256. Leaves of the blossom are really leaves. 257. Stamens a different modifi-
cation of the same. 258. Pistils another modification ; the botanist's idea of
a pistil. 259. The arrangement of the parts of a flower answers to that of the
leaves on a branch.
LESSON XV. MORPHOLOGY OF THE CALYX AND COROLLA. . . p. 99.
260. The leaves of the blossom viewed as to the various shapes they assume ;
as, 261. by growing together. 262. Union or cohesion of parts of the same sort,
rendering the flower, 263. Monopetalous or monosepalous ; various shapes de-
fined and named. 265 The tube, and the border or limb. 266. The claw
and the blade, or lamina of a separate petal, &e. 267. When the parts are
distinct, polysepalous, and polvpetalous. 268. Consolidation, or the growing
together of the parts of different sets. 269. Insertion, what it means, and what
i^ meant by the terms Free and Hypogynou*. 270. Perigynous insertion. 271,
272. Coherent or adherent calyx, &c. 273. Epigynous. 274. Irregularity of
parts. 275. Papilionaceous flower, and its parts. 276. Labiate or bilabiate
flower. 277. 278. Ligulate flowers : the so-called compound flowers.
ANALYSIS OF THE LESSONS. IX
LESSON XVI. ^ESTIVATION, OR THE ARRANGEMENT or THE
CALYX AND COROLLA IN THE BUD. ... p. 108.
279. ^Estivation or Prcefloration defined. 280. Its principal modes illustrated,
viz. the valvate, induplicatc, reduplicate, convolute or twisted, and imbricated.
282, 283. Also the open, and the plaited or plicate, and its modification, the
supervolute.
LESSON XVII. MORPHOLOGY OF THE STAMENS p. 111.
284. Stamens considered as to, 285. Their insertion. 286. Their union with
each other. 287, 288. Their number. 289. Their parts. 290. The Filament
291. The Anther. 292,293. Its attachment to the filament. 294. Its structure.
295. Its mode of opening, &c. 296. Its morphology, or the way in which it is
supposed to be constructed out of a leaf; its use, viz. to produce, 297. Pollen.
298. Structure of pollen-grains. 299. Some of their forms.
LESSON XVIII. MORPHOLOGY OF PISTILS p. 116.
300. Pistils as to position. 301. As to number. 302. Their parts ; Ovary,
style, and stigma. 303, 304. Plan of a pistil, whether simple or compound.
305, 306. The simple pistil, or Carpel, and how it. answers to a leaf. 307. Its
sutures. 308. The Placenta. 309. The Simple Pistil, one-celled, 310. and with
one style. 311, 312. The Compound Pistil, how composed. 313. With two or
more cells : 314. their placenta? in the axis : 315. their dissepiments or parti-
tions. 316, 317. One-celled compound pistils. 318. With a freo central pla-
centa. 319, 320. With parietal placenta?. 321. Ovary superior or inferior.
322. Open or Gymnospermous pistil : Naked-seeded plants. 323. Ovules. 324.
Their structure. 325, 326. Their kinds illustrated.
LESSON XIX. MORPHOLOGY OF THE RECEPTACLE p. 124.
327. The Receptacle or Torus. 328-330. Some of its forms illustrated.
331. The Disk. 332. Curious form of the receptacle in Nelumbium.
LESSON XX. THE FRUIT p. 126.
333. What the Fruit consists of. 334. Fruits which are not such in a strict
botanical sense. 335. Simple Fruits. 336, 337. The Pericarp, and the changes
it may undergo. 338 Kinds of simple fruits. 339. Fleshy fruits. 340 The
Berry. 341. The Pcpo or Ground-fruit. 342. The Pome or Apple-fruit. 343-
345. The Drupe or Stone-fruit. 346. Dry fruits. 347. The Achcnium : nature
of the Strawberry. 348. Raspberry and Blackberry. 349. Fruit in the Com-
posite Family : Pappus. 350. The Utricle. 351. The Caryopsis or Grain. 352.
The Nut : Cupule. 353. The Samara or Key-fruit. 354. The Capsule or Pod.
355. The Follicle. 356. The Legume and Loment. 357. The true Capsule.
358,359. Dehiscence, its kinds. 361. The Silique. 362. The Silicic. 363. The
Pyxis. 364. Multiple or Collective Fruits. 365. The Strobile or Cone.
X ANALYSIS OF THE LESSONS.
LESSON XXI. THE SEED p. 134.
366. The Seed; its origin. 367. Its parts. 360,369. Its coats. 370. The
Aril or Arillus. 371. Names applied to the parts of the seed. 372. The Ker-
nel or Nucleus. 373. The Albumen. 374, 375. The Embryo. 376. The
Radicle. 377. The Cotyledons or Seed-leaves : the monocotyledonous, dicoty-
ledonous, and polycotyledonous embryo. 378. The Plumule. 379. The circle
of vegetable life completed.
LESSON XXII. How PLANTS GROW p. 138.
380, 381. Growth, what it is. 382. For the first formation or beginning of
a plant dates farther back than to, 383. the embryo in the ripe seed, which is
already a plantlet. 384. The formation and the growth of the embryo itself.
385. Action of the pollen on the stigma, and the result. 386. The Embryonal
Vesicle, or first cell of the embryo. 387. Its growth and development into the
embryo. 388. Growth of the plantlet from the seed. 389. The plant built up
of a vast number of cells. 390. Growth consists of the increase iu size of cells,
and their multiplication in number.
LESSON XXIII. VEGETABLE FABRIC : CELLULAR TISSUE. . . p. 142.
391, 392. Organic Structure illustrated : Cells the units or elements of plants.
393. Cellular Tissue. 394, 395, 397. How the cells are put together. 396. Inter-
cellular spaces, air-passages. 398. Size of cells. 399. Rapidity of their produc-
tion. 400. Their walls colorless; the colors owing to their contents. 401. The
walls sometimes thickened. 402. Cells are closed and whole ; yet sap flows from
one cell to another. 403. Their varied shapes.
LESSON XXIV. VEGETABLE FABRIC : WOOD p. 145.
404. All plants at the beginning formed of cellular tissue only ; and some
never have anything else in their composition. 405. Wood soon appears in
most plants. 406. Its nature. 408. Wood-cells or Woody Fibre. 409. Hard
wood and soft wood. 410. Wood-cells closed and whole ; yet they convey sap.
411. They communicate through thin places : Pine-wood, &e. 412. Bast-cells
or fibres of the bark. 413. Ducts or Vessels. 414. The principal kinds. 415.
Milk-vessels, Oil-receptacles, c.
LESSON XXV. ANATOMY OF THE ROOT, STEM, AND LEAVES, p. 149.
416. The materials of the vegetable fabric, how put together. 417-419.
Structure and action of the rootlets. 420. -Root-hairs. 421. Structure of the
stem. 422. The two sorts of stem. 423. The Endogenous. 423. The Exo-
genous : 425. more particularly explained. 426. Parts of the wood or stem
itself. 427. Parts of the bark. 428. Growth of the exogenous stem year aftet
year. 429. Growth of the bark, and what becomes of the older parts. 431.
Changes in the wood ; Sap-wood. 432. Heart- wood. 433. This no longer lir-
ANALYSIS OF THE LESSONS. xl
ing. 434. What the living parts of a tree are; their annual renewal. 435.
Cambium-layer or zone of growth in the stem ; connected with, 436. new root-
lets below, and new shoots, buds, and leaves above. 437. Structure of a leaf :
its two parts, the woody and the cellular, or, 438. the pulp ; this contains the green
matter, or Chlorophyll. 439, 440. Arrangement of the cells of green pulp in the
leaf, and structure of its epidermis or skin. 441. Upper side only endures the
sunshine. 442. Evaporation or exhalation of moisture from the leaves. 443.
Stomates or Breathing-pores, their structure and use. 444. Their numbers.
LESSON XXVI. THE PLANT IN ACTION, DOING THE WORK
OF VEGETATION p. 157.
446. The office of plants to produce food for animals. 447. Plants feed
upon earth and air. 449. Their chemical composition. 450. Two sorts of
material. 451, 452. The earthy or inorganic constituents. 453. The organic
constituents. 454. These form the Cellulose, or substance of vegetable tissue ;
composition of cellulose. 455. The pla'nt's food, from which this is made.
456. Water, furnishing hydrogen and oxygen. 458. Carbonic acid, furnishing,
457. Carbon. 459. The air, containing oxygen and nitrogen ; and also, 460.
Carbonic acid; 461. which is absorbed by the leaves, 462. and by the roots.
463. Water and carbonic acid the general food of plants. 464. Assimilation
the proper work of plants. 465 Takes place in green parts alone, under the
light of the sun. 466-468. Liberates oxygen gas and produces Cellulose or
plant-fabric. 469. Or else Starch ; its nature and use. 470. Or Sugar; its na-
ture, c. The transformations starch, sugar, &c. undergo. 471. Oils, acids, &c.
The formation of all these products restores oxygen gas to the air. 472. There-
fore plants purify the air for animals. 473. While at the same time they pro-
duce all the food and fabric of animals. The latter take all their food ready made
from plants. 474. And decompose starch, sugar, oil, &c., giving back their ma-
terials to the air again as the food of the plant ; at the same time producing ani-
mal heat. 475. But the fabric or flesh of animals (fibrine, gelatine, c.) contains
nitrogen. 476 This is derived from plants in the form of Proteine. Its nature
and how the plant forms it. 477. Earthy matters in the plant form the earthy
part of bones, c. 478. Dependence of animals upon plants ; showing the great
object for which plants were created.
LESSON XXVII. PLANT-LIFE p. i 6 6.
479. Life; manifested by its effects ; viz its power of transforming matter:
480. And by motion. 481, 482. Plants execute movements as well as animals.
483. Circulation in cells. 484. Free movements of the simplest plants in their
forming state. 485. Absorption and conveyance of the sap. 486. Its rise into
the leaves. 487. Explained by a mechanical law; Erulosmose. 488. Set in ac-
tion by evaporation from the leaves. 489. These movements controlled by the
plant, which directs growth and shapes the fabric by an inherent power. 4SO -
492. Special movements of a conspicuous sort ; such as seen in the bending,
twining, revolving, and coiling of stems and tendrils ; in the so-called sleeping
and waking states of plants ; in movements from irritation, aud striking spon-
taneous motions.
Xii ANALYSIS OF THE LESSONS.
493. Cryptogamous or Flowerless Plants. 494. What they comprise ; why
so called. 495. To be studied in other works.
LESSON XXVIII. SPECIES AND KINDS p. 173.
496. Plants viewed as to their relationships. 497. Two characteristics of
plants and animals : they form themselves, and, 498. They exist as Individu-
als. The chain of individuals gives rise to the idea of, 499, 500. Species : as-
semblages of individuals, so like that they are inferred to have a common an-
cestry. 501. Varieties and Races. 502. Tendency of the progeny to inherit
all the peculiarities of the parent; how taken advantage of in developing and
fixing races. 503. Diversity and gradation of species ; these so connected as to
show all to be formed on one plan, all works of one hand, or realizations of the
conceptions of one mind. 504. Kinds, what they depend upon. 505. Genera.
506. Orders or Families. 507. Suborders and Tribes. 508 Classes. 509. The
two great Series or grades of plants. 510. The way the various divisions in
classification are ranked.
LESSON XXIX. BOTANICAL NAMES AND CHARACTERS. . . . p. 178.
511, 512. Classification ; the two purposes it subserves. 513. Names : plan of
nomenclature. 514, 515. Generic names, how formed. 516. Specific names,
how formed. 517. Names of Varieties. 518, 519. Names of Orders, Sub-
orders, Tribes, &c. 520, 521. Characters.
LESSONS XXX. -XXXII. How TO STUDY PLANTS, pp. 181, 187, 191.
522 - 567. Illustrated by several examples, showing the mode of analyzing and
ascertaining the name of an unknown plant, and its place in the system, &c.
LESSON XXXIII. BOTANICAL SYSTEMS . . p. 195.
568-571. Natural System. 572, 573. Artificial Classification. 574. Arti-
ficial System of Linnaeus. 575. Its twenty-four Classes, enumerated and de-
fined. 576. Derivation of their names. 577, 578. Its Orders.
LESSON XXXIV. How TO COLLECT SPECIMENS AND MAKE
AN HERBARIUM p- 199.
579-582. Directions for collecting specimens. 583, 584. For drying and
preserving specimens. 585, 586 For forming an Herbarium.
GLOSSARY, OR DICTIONARY OF BOTANICAL TERMS p. 203
FIRST LESSONS
IN
BOTANY AND VEGETABLE PHYSIOLOGY.
LESSON 1.
BOTANY AS A BRANCH OF NATURAL HISTORY.
1. THE subjects of Natural History are, the earth itself and the
beings that live upon it.
2. The Inorganic World, or Mineral Kingdom, The earth itself, with
the air that surrounds it, and all things naturally belonging to them
which are destitute of life, make up the mineral kingdom, or in-
organic world. These are called inorganic, or unorganized, because
they are not composed of organs, that is, of parts which answer to
one another, and make up a whole, such as is a horse, a bird, or a
plant. They were formed, but they did not grow, nor proceed from
previous bodies like themselves, nor have they the power of pro-
ducing other similar bodies, that is, of reproducing their kind. On
the other hand, the various living things, or those which have pos-
sessed life, compose
3. The Organic World, the world of organized beings. These
consist of organs ; of parts which go to make up an individual, a
being. And each individual owes its existence to a preceding one
like itself, that is, to a parent. It was not merely formed, but
produced. At first small and imperfect, it grows and develops by
powers of its own ; it attains maturity, becomes old, and finally dies.
It was formed of inorganic or mineral matter, that is, of earth and
air, indeed ; but only of this matter under the influence of life :
and after life departs, sooner or later, it is decomposed into earth
and air again.
1
2 BOTANY, WHAT IT RELATES TO. f LESSON 1.
4. The organic world consists of two kinds of beings ; namely,
1. Plants or Vegetables, which make up what is called the Vegetable
Kingdom ; and, 2. Animals, which compose the Animal Kingdom.
5. The Differences between Plants and Animals seem at first sight so
obvious and so great, that it would appear mere natural to inquire
how they resemble rather than how they differ from each other.
What likeness does the cow bear to the grass it feeds upon ? The
one moves freely from place to place, in obedience to its own will,
as its wants or convenience .require : the other is fixed to the spot
of earth where it grew, manifests no will, and makes no movements
that are apparent to ordinary observation. The one takes its food
into an internal cavity (the stomach), from which it is absorbed
into the system : the other absorbs its food directly by its surface,
by its roots, leaves, &c. Both possess organs; but the limbs or
members of the animal do not at all resemble the roots, leaves,
blossoms, &c. of the plant. All these distinctions, however, gradu-
ally disappear, as we come to the lower kinds of plants and the lower
animals. Many animals (such as barnacles, coral-animals, and
polyps) are fixed to some support as completely as the plant is to
the soil ; while many plants are not fixed, and some move from
place to place by powers of their own. All animals move some of
their parts freely ; yet in the extent and rapidity of the motion
many of them are surpassed by the common Sensitive Plant, by
the Venus's Fly-trap, and by some other vegetables ; while whole
tribes of aquatic plants are so freely and briskly locomotive, that
they have until lately been taken for animals. It is among these
microscopic tribes that the animal and vegetable kingdoms most
nearly approach each other, so nearly, that it is still uncertain
where to draw the line between them.
6. Since the difficulty of distinguishing between animals and
plants occurs only, or mainly, in those forms which from their
minuteness are beyond ordinary observation, we need not further
concern ourselves with the question here. One, and probably the
most absolute, difference, however, ought to be mentioned at the
outset, because it enables us to see what plants are made for. It
is this:
7. Vegetables are nourished by the mineral kingdom, that is, by
the ground and the air, which supply all they need, and which they
are adapted to live upon ; while animals are entirely nourished by
vegetables. The great use of plants therefore is, to take portions of
LESSON 1.] BOTANY, WHAT IT RELATES TO. 3
earth and air, upon which animals cannot subsist at all, and to con-
vert these into something upon which animals can subsist, that is,
into food. All food is produced by plants. How this is done, it is
the province of Vegetable Physiology to explain.
8. Botany is the name of the science of the vegetable kingdom in
general.
9. Physiology is the study of the way a living being lives, and
grows, and performs its various operations. The study of plants in
this view is the province of Vegetable Physiology. The study of the
form and structure of the organs or parts of the vegetable, by which
its operations are performed, is the province of Structural Botany.
The two together constitute Physiological Botany. With this de-
partment the study of Botany should begin ; both because it lies
at the foundation of all the rest, and because it gives that kind of
knowledge of plants which it is desirable every one should possess ;
that is, some knowledge of the way in which plants live, grow, and
fulfil the purposes of their existence. To this subject, accordingly,
a large portion of the following Lessons is devoted.
10. The study of plants as to their kinds is the province of Sys-
tematic Botany. An enumeration of the kinds of vegetables, as far
as known, classified according to their various degrees of resemblance
ttr difference, constitutes a general System of plants. A similar ac-
count of the vegetables of any particular country or district is called
a Flora of that country or district.
1 1 . Other departments of Botany come to view when instead
of regarding plants as to what they are in themselves, or as to their
relationship with each other we consider them in their relations
to other things. Their relation to the earth, for instance, as respects
their distribution over its surface, gives rise to Geographical Botany,
or Botanical Geography. The study of the vegetation of former
times, in their fossil remains entombed in the crust of the earth,
gives rise to Fossil Botany. The study of plants in respect to their
uses to man is the province of Agricultural Botany, Medical Botany t
and the like.
4 GROWTH OF THE PLANT FROM THE SEED. [LESSON 2.
LESSON II.
THE GROWTH OF THE PLANT FROM THE SEED.
12. The Course of Vegetation, We see plants growing from the
seed in spring-time, and gradually developing their parts : at length'
they blossom, bear fruit, and produce seeds like those from which
they grew. Shall we commence the study of the plant with the
full-grown herb or tree, adorned with flowers or laden with fruit ?
Or shall we commence with the seedling just rising from the
ground ? On the whole, we may get a clearer idea of the whole
life and structure of plants if we begin at the beginning, that is, with
the plantlet springing from the seed, and follow it throughout its
course of growth. This also agrees best with the season in which
the study of Botany is generally commenced, namely, in the spring
of the year, when the growth of plants from the seed can hardly
fail to attract attention. Indeed, it is this springing forth of vegeta-
tion from seeds and buds, after the rigors of our long winter,
clothing the earth's surface almost at once with a mantle of freshest
verdure, which gives to spring its greatest charm. Even the
dullest beholder, the least observant of Nature at other seasons,
can then hardly fail to ask : What are plants ? How do they live
and grow ? What do they live upon ? What is the object and use
of vegetation in general, and of its particular and wonderfully various
forms ? These questions it is the object of the present Lessons to
answer, as far as possible, in a simple way.
13. A reflecting as well as observing person, noticing the re-
semblances between one plant and another, might go on to inquire
whether plants, with all their manifold diversities of form and
appearance, are not all constructed on one and the same general
plan. It will become apparent, as we proceed, that this is the
case; that one common plan may be discerned, which each par-
ticular plant, whether herb, shrub, or tree, has followed much more
closely than would at first view be supposed. The differences, wide
as they are, are merely incidental. What is true in a general way
of any ordinary vegetable, will be found to be true of all, only with
great variation in the details. In the same language, though in
varied phrase, the hundred thousand kinds of plants repeat the same
LESSON 2.] GROWTH OF THE PLANT FROM THE SEED.
story, are the living witnesses and illustrations of one and the
same plan of Creative Wisdom in the vegetable world. So that the
study of any one plant, traced from the seed it springs from round
to the seeds it produces, would illustrate the whole subject of vege-
table life and growth. It matters little, therefore, what particular
plant we begin with.
14. The Germinating Plantlet, Take for example a seedling Maple,,.
Sugar Maples may be found in abundance in many places, starting
from the seed (i. e. germinating) in early spring, and Red Maples
at the beginning of summer, shortly after the fruits of the season
have ripened and fallen to the ground. A pair of narrow green
leaves raised on a tiny stem make up the whole plant at its first
appearance (Fig. 4). Soon a root appears at the lower end of this
stemlet ; then a little bud at its upper end, between the pair of
leaves, which soon grows into a second joint or
stem bearing another pair of leaves, resembling
the ordinary leaves of the Red Maple, which
the first did not. Figures 5 and 6 represent
these steps in the growth.
15. Was this plantlet formed in the seed at
the time of germination, something as the chick
is formed in the egg during the process of incu-
bation ? ' Or did it exist before in the seed,
ready formed ? To decide this question, we
have only to inspect a sound seed, which in this
instance requires no microscope, nor any other
instrument than a sharp knife, by which the
coats of the seed (previously soaked in water, if
dry) may be laid open. We find within the
seed, in this case, the little plantlet ready formed,
and nothing else (Fig. 2) ; namely, a pair
of leaves like those of the earliest seedling
(Fig. 4), only smaller, borne on a stemlet just
like that of the seedling, only much shorter,
and all snugly coiled up within the protecting
seed-coat. The plant then exists beforehand
in the seed, in miniature. It was not formed, but only devel-
FIG. 1. A winged fruit of Red Maple, with the seed-bearing portion cut open, to show th
seed. 2. This seed cut open to show the embryo plantlet within, enlarged. 3. The embryo
taken out whole, and partly unfolded. 4. The same after it has begun to grow ; of the
natural size.
1*
GROWTH OF THE PLANT FROM THE SEED. [LESSON 2.
oped, in germination ; when it had merely to unfold and grow,
to elongate its rudimentary stem, which takes
at the same time an upright position, so as to
bring the leaf-bearing end into the light and air,
where the two leaves expand ; while from the
opposite end, now pushed farther downwards
into the soil, the root begins to grow. All this
is true in the main of all plants that spring from
real seeds, although with great diversity in the
particulars. At least, there is hardly an excep-
tion to the fact, that the plantlet exists ready
formed in the seed, in some shape or other.
16. The rudimentary plantlet contained in
the seed is called an Embryo. Its little stem
is named the Radicle, because it was supposed
to be the root, when the difference between the
root and stem was not so well known as now.
It were better to name it the Caulicle (i. e.
little stem) ; but it is not expedient to change
old names. The seed-leaves it bears on its sum-
mit (here two in number) are technically called
Cotyledons. The little bud of undeveloped
leaves which is to be found between* the co-
tyledons before germination in many cases (as in the Pea, Bean,
Fig. 17, &c.), has been named the Plumule.
17. In the Maple (Fig. 4), as also in the Morning-Glory (Fig.
28), and the like, this bud, or plumule, is not seen for some days
after the seed-leaves are expanded. But soon it appears, in the
Maple as a pair of minute leaves (Fig. 5), erelong raised on a stalk
which carries them up to some distance above the cotyledons. The
plantlet (Fig. 6) now consists, above ground, of two pairs of leaves,
viz. : 1. the cotyledons or seed-leaves, borne on the summit of the
original stemlet (the radicle) ; and 2. a pair of ordinary leaves,
raised on a second joint of stem which has grown from the top
of the first Later, a third pair of leaves is formed, and raised
on a third joint of stem, proceeding from the summit of the second
(Fig. 7), just as that did from the first ; and so on, until the germi~
nating plantlet becomes a tree.
FIG. 5. Germinating Red Maple, which has produced its root beneath, and is developinf
* second pair of leaves above. 6. Same, further advanced.
LESSON 2.] GROWTH OF THE PLANT FROM THE SEED.
18. So the youngest seedling, and even the embryo in the seed_
is already an epitome of the herb or tree. It has a stem, from the
lower end of which it strikes root ; and it
has leaves. The tree itself in its whole
vegetation has nothing more in kind.
To become a tree, the plantlet has only
to repeat itself upwardly by producing
jnore similar parts, that is, new por-
tions of stem, with new and larger leaves,
in succession, while beneath, it pushes
its root deeper and deeper into the soil.
19. The Opposite Growth of Root and
Stem began at the beginning of germi-
nation, and it continues through the
whole life of the plant. While yet
buried in the soil, and perhaps in total
darkness, as soon as it begins to grow,
the stem end of the embryo points
towards the light, curving or turning
quite round if it happens to lie in
some other direction, and stretches
upwards into the free air and sunshine ;
while the root end as uniformly avoids
the light, bends in the opposite direction
to do so if necessary, and ever seeks to bury itself more and more
in the earth's bosom. How the plantlet makes these movements we
cannot explain. But the object of this instinct is obvious. It
places the plant from the first in the proper position, with its roots
in the moist soil, from which they are to absorb nourishment, and its
leaves in the light and air, where alone they can fulfil their office of
digesting what the roots absorb.
20. So the seedling plantlet finds itself provided with all the
organs of vegetation that even the oldest plant possesses, namely,
root, stem, and leaves ; and has these placed in the situation where
each is to act, the root in the soil, the foliage in the light and air.
Thus established, the plantlet has only to set about its proper work.
21. The different Mode of Growth of Root and Stem may also be here
mentioned. Each grows, not only in a different direction, but in a
different way. The stem grows by producing a set of joints, each from
FIG. 7. Germinating Red Mapleu further developed.
8 GROWTH OF THE PLANT FROM THE SEED. [LESSON 2.
the summit of its predecessor ; and each joint elongates throughout
every part, until it reaches its full length. The root is not composed
of joints, and it lengthens only at the end. The stem in the embryo
(viz. the radicle) has a certain length to begin with. In the pump-
kin-seed, for instance (Fig. 9), it is less than an eighth of an inch
long : but it grows in a few days to the length of one or two inches
(Fig. 10), or still more, if the seed were deeper covered by the soil.
It is by this elongation that the seed-leaves are raised out of the
soil, so as to expand in the light and air. The^ length they acquire
varies with the depth of the covering. When large and strong seeds
are too deeply buried, the stemlet sometimes grows to the length of
several inches in the endeavor to bring the seed-leaves to the sur-
face. The lengthening of the succeeding joints of the stem serves to
separate the leaves, or pairs of leaves, from one another, and to ex-
pose them more fully to the light.
22. The root, on the other hand, begins by a new formation at
the base of the embryo stem ; and it continues to increase in length
solely by additions to the extremity, the parts once formed scarcely
elongating at all afterwards. This mode of growth is well adapted
to the circumstances in which roots are placed, leaving every part
undisturbed in the soil where it was formed, while the ever-advan-
cing points readily insinuate themselves into the crevices or looser
portions of the soil, or pass around the surface of solid obstacles.
LESSON 3.] GROWTH OF THE PLANT FROM THE SEED. 9
LESSON III.
GROWTH OF THE PLANT FROM THE SEED. Continued.
23. So a plant consists of two parts, growing in a different manner.
^as well as in opposite directions. One part, the root, grows down-
wards into the soil : it may, therefore, be called the descending axis.
The other grows upwards into the light and air : it may be called
the ascending axis. The root grows on continuously from the ex-
tremity, and so does not consist of joints, nor doe* it bear leaves,
or anything of the kind. The stem grows by a succession of
joints, each bearing one or more leaves on its summit. Root on
the one hand, and stem with its foliage on the other, make up the
whole plantlet as it springs from the seed ; and the full-grown herb,
shrub, or tree has nothing more in kind, only more in size and
number. Before we trace the plantlet into the herb or tree, some
other cases of the growth of the plantlet from the seed should be
studied, that we may observe how the same plan is worked out under
a variety of forms, with certain differences in the details. The mate-
rials for this study are always at hand. We have only to notice what
takes place all around us in spring, or to plant some common seeds
in pots, keep them warm and moist, and watch their germination.
24. The Germinating Plantlel feeds on Nourishment provided beforehand.
The embryo so snugly ensconced in the seed of the Maple (Fig. 2,
3, 4) has from the first a miniature stem, and a pair of leaves already
green, or which become green as soon as brought to the light. It
has only to form a root by which to fix itself to the ground, when it
becomes a perfect though diminutive vegetable, capable of providing
for itself. This root can be formed only out of proper material :
neither water nor anything else which the plantlet is imbibing from
the earth will answer the purpose. The proper material is nourish-
ing matter, or prepared food, more or less of which is always pro-
vided by the parent plant, and stored up in the seed, either in the
embryo itself, or around it. In the Maple, this nourishment is stored
up in the thickish cotyledons, or seed-leaves. And there is barely
enough of it to make the beginning of a root, and to provide for the
lengthening of the stemlet so as to bring up the unfolding seed-leaves
where they may expand to the light of day. But when this is done,
S&F 2
10
GROWTH OF THE PLANT FROM THE SEED. [LESSON 3.
the tiny plant is already able to shift for itself; that is, to live and
continue its growth on what it now takes from the soil and from the
air, and elaborates into nourishment in its two green leaves, under
the influence of the light of the sun.
25. In most ordinary plants, a larger portion of nourishment is
provided beforehand in the seed ; and the plantlet consequently is
not so early or so entirely left to its own resources. Let us examine
a number of cases, selected from very common plants. Sometimes,
as has just been stated, we find this
26. Deposit Of Food in the Embryo itself, And we may observe it
in every gradation as to quantity, from the Maple of our first illus-
tration, where there is very little, up to
the Pea and the Horsechestnut, where
there is as much as there possibly can
be. If we strip off the coats from the
large and flat seed of a Squash or
Pumpkin, we find nothing but the em-
bryo within (Fig. 9) ; and almost the
whole bulk of this consists of the two
seed-leaves. That these contain a good
supply of nourishing matter, is evident
from their sweet taste and from their
thickness, although there is not enough
to obscure their leaf-like appearance.
It is by feeding on this supply of nour-
ishment that the germinating Squash or
Pumpkin (Fig. 10) grows so rapidly
and so vigorously from the seed,
lengthening its stemlet to more than
twenty times the length it had in the
seed, and thickening it in proportion,
sending out at once a number of roots
from its lower end, and soon developing
the plumule (16) from its upper end into a third leaf: meanwhile
the two cotyledons, relieved from the nourishment with which their
tissue was gorged, have expanded into useful green leaves.
27. For a stronger instance, take next the seed of a Plum or
Peach, or an Almond, or an Apple-seed (Fig. 11, 12), which shows
FIG. 9. Embryo of a Pumpkin, of the natural size ; the cotyledons a little opened
JO. The same, when it has germinated.
LESSON 3.] GROWTH OF THE PLANT FROM THE SEED.
11
the same thing on a smaller scale. The embryo, which here also
makes up the whole bulk of the kernel of the
seed, differs from that of the Pumpkin only
in having the seed-leaves more thickened, by
the much larger quantity of nourishment stored
up in their tissue, so large and so pure in-
deed, that the almond becomes an article of
food. Fed by this abundant supply, the second,
and even the third joints of the stem, with
their leaves, shoot forth as soon as the stemlet comes to the surface oi
the soil. The Beech-nut (Fig. 13), with
its sweet and eatable kernel, consisting
mainly of a pair of seed-leaves folded
together, and gorged with nourishing
matter, offers another instance of the
same sort : this ample store to feed
upon enables the germinating plantlet
to grow with remarkable vigor, and to
develop a second joint of stem, with its
pair of leaves (Fig. 14), before the first
pair has expanded or the root has ob-
tained much foothold in the soil.
28. A Bean affords a similar and
more familiar illustration. Here the co-
tyledons in the seed (Fig. 16) are so
thick, that, although they are raised out
of ground in the ordinary way in ger-
mination (Fig. 17), and turn greenish,
yet they never succeed in becoming leaf-
like, never display their real nature of
leaves, as they do so plainly in the Ma-
ple (Fig. 5), the Pumpkin (Fig. 10), the
Morning-Glory (Fig. 8, 26-28), &c.
Turned to great account as magazines
of food for the germinating plantlet, they
fulfil this special office admirably, but
FIG. 11. An Apple-seed cut through lengthwise, showing the embryo with its thickened
cotyledons. 12. The embryo of the Apple, taken out whole, its cotyledons partly separated
FIG. 13. A Beech-nut, cut across. 14. Beginning germination of the Beech, showing the
plumule growing before the cotyledons have opened or the root has scarcely formed. 15. The
tame, a little later, with the second joint lengthened.
12
GROWTH OF THE PLANT FROM THE SEED. ^LESSON 3.
they were so gorged and, as it were, misshapen, that they became
quite unfitted to perform the office of
foliage. This office is accordingly first
performed by the succeeding pair of
leaves, those of the plumule (Fig. 17,
18), which is put into rapid growth by
the abundant nourishment contained in
the large and thick seed-leaves. The
latter, having fulfilled this office, soon
wither and fall away.
29. This is carried a step farther in
the Pea (Fig. 19, 20), a near relative
of the Bean,
and in the
Oak (Fig.
21, 22), a
near relative
of the Beech.
The differ-
ence in these
and many
other similar
cases is this.
The cotyledons, which make up nearly
the whole bulk of the seed are exces-
sively thickened, so as to become nearly
hemispherical in shape. They have lost
all likeness to leaves, and all power of
ever fulfilling the office of leaves. Ac-
cordingly in germination they remain
unchanged within the husk or coats of
the seed, never growing themselves, but
supplying abundant nourishment to the
plumule (the bud for the forming stem)
between them. This pushes forth from
the seed, shoots upward, and gives rise
FIG. 16, A Bean : the embryo, from which seed-coats have been removed : the smal)
stem is seen above, bent down upon the edge of the thick cotyledons. 17. The same in early
germination ; the plumule growing from between the two seed-leaves. 18. The germination
more advanced., the two leaves of the plumule unfolded, and raised on a short joint of stem.
FIG, 19. A Pea: the embryo, with the seed-coats taken off. 20. A Pea in germination.
LESSON 3.] GROWTH OF THE PLANT FROM THE SEED.
to the first leaves that appear. In most cases of the sort, the radicle,
or short original stemlet of the embryo be-
low the cotyledons (which is plainly shown
in the Pea, Fig. 19), lengthens very little,
or not at all; and so the cotyledons remain
under ground, if the seed was covered by
the soil, as every one knows to be the case
with Peas. In these (Fig. 20), as also in
the Oak (Fig. 22), the leaves of the first
one or two joints are imperfect, and mere
small scales ; but genuine leaves immedi-
ately follow. The Horsechestnut and Buck-
eye (Fig. 23, 24) furnish another instance
of the same sort. These trees are nearly
related to the Maple ; but while the seed-
leaves of the Maple show themselves to
be leaves, even in the seed (as we have
already seen), and when they germinate
fulfil the office of ordinary leaves, those
of the Buckeye and of the Horsechestnut
(Fig. 23), would never be suspected to be
the same organs. Yet they are so, only
in another shape, exceedingly thickened
by the accumulation of a great quantity
of starch and other nourishing matter in
their substance ; and besides, their contigu-
ous faces stick together more or less firmly,
so that they never open. But the stalks
of these seed-leaves grow, and, as they
lengthen, push the radicle and the plumule 22
out of the seed, when the former develops downwardly the root, the
latter upwardly the leafy stem and all it bears (Fig. 24).
30. Deposit of Food OQtside Of the Embryo. Very often the nourish-
ment provided for the seedling plantlet is laid up, not in the embryo
itself, but around it. A good instance to begin with is furnished by
the common Morning-Glory, or Convolvulus. The embryo, taken
out of the seed and straightened, is shown in Fig. 26. it consists
of a short stemlet and of a pair of very thin and delicate green
leaves, ha.ving no stock of nourishment in them for sustaining the
FIG. 21. An acorn divided lengthwise. 22. The germinating Oak.
2
14
GROWTH OF THE PLANT FROM THE SEED. [LESSON 3.
earliest growth. On cutting open the seed, however, we find this
embryo (considerably crumpled or folded together, so as to occupy-
less space, Fig. 25) to be surround-
ed by a mass of rich, mucilaginous;
matter (becoming rather hard and
solid when dry), which forms the
principal bulk of the seed. Upon
this stock the embryo feeds in ger-
mination ; the seed-leaves absorbing
it into their tissue as it is rendered
soluble (through certain chemical
changes) and dissolved by the wa-
ter which the germinating seed im-
bibes from the moist soil. Having
by this aid & as
lengthened
its radicle
into a stem
of consider-
able length,
and formed the beginning of a root at its
lower end, already imbedded in the soil
(Fig. 27), the cotyledons now disengage
themselves from the seed-coats, and ex-
pand in the light as the first pair of leaves
(Fig. 28). These immediately begin to
elaborate, under the sun's influence, what
the root imbibes from the soil, and the new
nourishment so produced is used, partly to
increase the size of the little stem, root,
and leaves already existing, and partly to
produce a second joint of stem with its
leaf (Fig. 29), then a third with its leaf
(Fig. 8) ; and so on.
31. This maternal store of food, deposited in the seed along with
the embryo (but not in its substance), the old botanists likened to
FIG. 23. Buckeye : a seed divided. 24. A similar seed in gemination.
FIG. 25. Seed and embryo of Morning-Glory, cut across. 26. Embryo of the same, de.
tached and straightened. 27. Germinating Morning-Glory . 28. The same further advanced,-
its two thin seed-leaves expanded.
LESSON 3.] GROWTH OF THE PLANT FROM THE SEED.
15
the albumen, or white of the egg, which encloses the yolk, and
therefore gave it the same name, the albumen of the seed, a
name which it still retains. Food of this sort for the plant is also
food for animals, or for man ; and it is
this albumen, the floury part of the seed,
which forms the principal bulk of such
important grains as those of Indian Corn
(Fig. 38 - 40), Wheat, Rice, Buck-
wheat, and of the seed of Four-o'clock,
(Fig. 36, 37), and the like. In all
these last-named cases, it may be ob-
served that the embryo is not enclosed
in the albumen, but placed on one side
of it, yet in close contact with it, so
that the embryo may absorb readily
from it the nourishment it requires
when it begins to grow. Sometimes
the embryo is coiled around the outside, in the form of a ring, as
in the Purslane and the Four-o'clock (Fig. 36, 37) ; sometimes it is
coiled within the albumen, as in the Potato (Fig. 34, 35) ; some-
times it is straight in the centre of the albumen, occupying nearly its
so 32 34 36 whole length, as in
the Barberry (Fig.
32, 33), or much
smaller and near one
end, as in the Iris
(Fig. 43) ; or some-
times so minute, in
the midst of the al-
bumen, that it needs
a magnifying-glass to
find it, as in the But-
37
FIG. 29. Germination of the Morning Glory more advanced : the upper part only ; showing
the leafy cotyledons, the second joint of stein with its leaf, and the third with its leaf just
developing.
FIG. 30. Section of a seed of a Peony, showing a very small embryo in the albumen,
near one end. 31. This embryo detached, and more magnified.
FIG. 32. Section of a seed of Barberry, showing the straight embryo in the middle of
the albumen. 33. Its embryo detached.
FIG. 34. Section oi a Potato-seed, showing the embryo coiled in the albumen. 35. Its
embryo detached.
FIG. 36. Section of the seed of Four-o'clock, showing the embryo coiled round tfi
outside of the albumen. 37. Its embryo detached*
16 GROWTH OF THE PLANT FROM THE SEED. [LESSON 3.
tercup or the Columbine, and in the Peony (Fig. 30, 31), where,
however, it is large enough to be distinguished by the naked eye.
Nothing is more curious than the various shapes and positions of
the embryo in the seed, nor more interesting than to watch its de-
velopment in germination. One point is still to be noticed, since
the botanist considers it of much importance, namely :
32. The Kinds of Embryo as to the Number of Cotyledons, In all the
figures, it is easy to see that the embryo, however various in shape,
is constructed on one and the same plan ; it consists of a radicle or
stemlet, with a pair of cotyledons on its summit. Botanists there-
fore call it dicotyledonous, an inconveniently long word to express
the fact that the embryo has two cotyledons or seed-leaves. In
many cases (as in the Buttercup), the cotyledons are indeed so
minute, that they are discerned only by the nick in the upper end
of the little embryo ; yet in germination they grow into a pair of
seed-leaves, just as in other cases where they are plain to be seen,
as leaves, in the seed. But in Indian Corn (Fig. 40), in Wheat,
the Onion, the Iris (Fig. 43), &c., it is well known that only one
leaf appears at first from the
sprouting seed : in these the
embryo has only one cotyle-
don, and it is therefore termed
by the botanists monocotyledo-
nous ; an extremely long
word, like the other, of Greek derivation, which means one-cotyle-
doned. The rudiments of one or more other leaves are, indeed,
commonly present in this sort of embryo, as is plain to see in Indian
Corn (Fig. 38 - 40), but they form a bud situated above or within
the cotyledon, and enclosed by it more or less completely ; so thai,
they evidently belong to the plumule (16); and these leaves appear
in the seedling plantlet, each from within its predecessor, and there-
fore originating higher up on the forming stem (Fig. 42, 44). This
will readily be understood from the accompanying figures, with their
explanation, which the student may without difficulty verify for him-
FIG. 38. A grain of Indian Corn, flatwise, cut away a little, so as to show the embryo,
lying on the albumen, which makes the principal bulk of the peed.
FIG. 39. Another grain of Corn, cut through the middle in the opposite direction, divid-
ing the embryo through its thick cotyledon and its plumule, the latter consisting of two
leaves, one enclosing the other.
FIG. 40. The embryo of Corn, taken out whole : the thick mass is the cotyledon ; the
narrow body partly enclosed by it is the plumule ; the little projection at its base is the very
hort radicle enclosed in the sheathing base of the first leaf of the plumule.
tESSON 3.] GROWTH OF THE PLANT FROM THE SEED. 17
self, and should do so, by examining grains of Indian Corn, soaked
in water, before and also during germination. In the Onion, Lily,
and the Iris (Fig. 43), the monocotyledonous embryo is simpler,
consisting apparently of a simple oblong or cylindrical
body, in which no distinction of parts is visible : the lower
end is radicle, and from it grows the root ; the rest is a
cotyledon, which has wrapped up in it a minute plumule,
or bud, that shows itself when the seeds sprout in germi-
nation. The first leaf which appears above ground in all
these cases is not the cotyledon. In all seeds with one coty-
ledon to the embryo, this remains in the seed, or at least
its upper part, while its lengthening base, comes out, so as
to extricate the plumule, which shoots upward, and de-
velops the first leaves of the plantlet. These appear one
above or within the other in succes-
sion, as is shown in Fig. 42 and
Fig. 44, the first commonly in the
form of a little scale or imperfect
leaf; the second or third and the 4l
following ones as the real, ordinary leaves of
the plant. Meanwhile, from the root end of
the embryo, a root (Fig. 41, 44), or soon a
whole cluster of roots (Fig. 42) , makes its
appearance.
33. In Pines, and the like, the embryo con-
sists of a radicle or stemlet, bearing on ite
summit three or four, or often from five to
ten slender cotyledons, arranged in a
circle (Fig. 45), and expanding at
once into a circle of as many green
leaves in germination (Fig. 46). Such
embryos are said to \tepolycotyledonous.
that is, as the word denotes, many-
cotyledoned.
34. Plan of Vegetation, The student
who has understandingly followed the
growth of the embryo in the seed into the seedling plantlet, com-
posed of a root, and a stem of two or three joints, each bearing a
FIG. 41. Grain of Indian Corn in germination.
FIG. 42. The same, further advanced
2*
18
GROWTH OF THE PLANT FROM THE SEED. [^LESSON 3.
leaf, or a pair (rarely a circle) of leaves, will have gained a cor-
rect idea of the plan of vegetation in general, and have laid a good
foundation for a knowledge of the whole structure and physiology
43 of plants. For the plant goes on to grow in the same
way throughout, by mere repetitions of what the early
germinating plantlet displays to view, of what was
contained, in miniature or in rudiment, in the seed itself.
So far as vegetation is concerned (leaving out of view
for the present the flower and fruit), the full-grown leafy
herb or tree, of whatever size, has nothing, and does
nothing, which the seedling plantlet does not have and
do. The whole mass of stem or trunk and foliage of
the complete plant, even of the largest forest-tree, is
composed of a succession or multiplication of similar
parts, one arising from the summit of another,
each, so to say, the offspring of the preceding and
the parent of the next.
35. In the same way that the earliest portions of
the seedling stem, with the leaves
they bear, are successively produced,
so, joint by joint in direct succes-
sion, a single, simple, leafy stem is
developed and carried up. Of such a
simple leafy stem many a plant consists
(before flowering, at least), many
herbs, such as Sugar-Cane, Indian
Corn, the Lily, the tall Banana, the
Yucca, &c. ; and among trees the
Palms and the Cycas (wrongly called
Sago Palm) exhibit the same simplicity, their
stems, of whatever age, being unbranched columns 45
(Fig. 47). (Growth in diameter is of course to be considered,
as well as growth in length. That, and the question how growth
of any kind takes place, we will consider hereafter.) But more
commonly, as soon as the plant has produced a main stem of a cer-
tain length, and displayed a certain amount of foliage, it begins to
FIG. 43. Section of a seed of the Iris, or Flower-de-Luce, showing its small embryo in
Ihe albumen, near the bottom.
FIG. 44. Germinating plantlet of the Iris.
FIG. 45. Section of a seed of a Pine, with its embryo of several cotyledons. 46. Early
seedling Pine, with its stem let, displaying its six seed-leaves.
LESSON 3.] GROWTH OF THE PLANT FROM THE SEED.
19
produce additional stems, that is, branches. The branching plant
we will consider in the next Lesson.
36. The subjoined figures (Fig. 47) give a view of some forms
of simple-stemmed vegetation. The figure in the foreground on
the left represents a Cycas (wrongly called in the conservatories
Sago Palm). Behind it is a Yucca (called Spanish Bayonet at the
South) and two Cocoanut Palm-trees. On the right is some Indian
Corn, and behind it a Banana.
20 GROWTH OF PLANTS FROM BUDS. (_LESSON 4.
LESSON IV.
THE GROWTH OF PLANTS FROM BUDS AND BRANCHES.
37. WE have seen how the plant grows so as to produce a root,
and a simple stem with its foliage. Both the root and stem, how-
ever, generally branch.
38. The branches of the root arise without any particular order.
There is no telling beforehand from what part of a main root they
will spring. But the branches of the stem, except in some extra-
ordinary cases, regularly prise from a particular place. Branches
or shoots in their undeveloped state are
39. Buds, These regularly appear in the axils of the leaves,
that is, in the angle formed by the leaf with the stem on the upper
side ; and as leaves are symmetrically arranged on the stem, the
buds, and the branches into which the buds grow, necessarily par-
take of this symmetry.
40. We do not confine the name of bud to the scaly winter-buds
which are so conspicuous on most of our shrubs and trees in winter
and spring. It belongs as well to the forming branch of any herb, at
its first appearance in the axil of a leaf. In growing, buds lengthen
into branches, just as the original stem did from the plumule of the
embryo (16) when the seed germinated. Only, while the original
stem is implanted in the ground by its root, the branch is implanted
on the stem. Branches, therefore, are repetitions of the main stem.
They consist of the same parts, namely, joints of stem and leaves,
growing in the same way And in the axils of their leaves
another crop of buds is naturally produced, giving rise to another
generation of branches, which may in turn produce still another
generation ; and so on, until the tiny and simple seedling develops
into a tall and spreading herb or shrub ; or into a massive tree,
with its hundreds of annually increasing branches, and its thousands,
perhaps millions, of leaves.
41. The herb and the tree grow in the same way. The difference
is only in size and duration.
An Herb dies altogether, or dies down to the ground, after it has
ripened its fruit, or at the approach of winter.
LESSON 4.J GROWTH OF PLANTS FROM BUDS.
21
An annual herb flowers in the first year, and dies, root and all,
after ripening its seed : Mustard, Peppergrass, Buckwheat, &c., are
examples.
A biennial herb such as the Turnip, Carrot, Beet, and Cabbage
grows the first season without blossoming, survives the winter,
flowers after that, and dies, root and all, when it has ripened its seed.
A perennial herb lives and blossoms year after year, but dies
down to the ground, or near it, annually, not, however, quite down
to the root : for a portion of the stem, with its buds, still survives ;
and from these buds the shoots of the following year arise.
A Shrub is a perennial plant, with woody stems which continue
alive and grow year after year.
A Tree differs from a shrub only in its greater size.
42. The Terminal Bud, There are herbs, shrubs, and trees which
do not branch, as we have already seen (35) ; but whose stems,
even when they liv for many years, rise as a simple shaft
(Fig. 47). These plants grow by the continued evolution of a bud
which crowns the summit of the stem, and which is therefore called
the terminal bud. This bud is very conspicuous in
many branching plants also ; as on all the stems or
shoots of Maples (Fig. 53), Horsechestnuts (Fig. 48),
or Hickories (Fig. 49), of a year old. When they
grow, they merely prolong the shoot or stem on which
they rest. On these same shoots, however, other buds
are to be seen, regularly arranged down their sides.
We find them situated just over broad, flattened places,
which are the scars left by the fall of the leaf-stalk the
autumn previous. Before the fall of the leaf, they
would have been seen to occupy their axils (39) : so
they are named
43. Axillary Buds, They were formed in these trees
early in the summer. Occasionally they grow at the
time into branches : at least, some of them are pretty
sure to do so, in case the growing terminal bud at the
end of the shoot is injured or destroyed. Otherwise
they lie dormant until the spring. In many trees
or shrubs (such for example as the Sumach and Honey-Locust)
these axillary buds do not show themselves until spring ; but if
FIG. 48. Shoot of Horsechestnut, of one year's growth, taken in autumn after the ieaveg
iave fallen.
22
GROWTH OF PLANTS FROM BUDS. [LESSON 4.
searched for, they may be detected, though of small size, hidden
under the bark. Sometimes, although early formed, they are con-
cealed all summer long under the base of the leaf-
stalk, hollowed out into a sort of inverted cup, like a
candle-extinguisher, to cover them ; as in the Locust,
the Yellow-wood, or more strikingly in the Button-
wood or Plane-tree (Fig. 50).
44. Such large and conspicuous buds as those of
the Horsechestnut, Hickory, and the like, are scaly ;
the scales being a kind of imperfect leaves. The
use of the bud-scales is obvious ; namely, to protect
the tender young parts beneath. To do this more
effectually, they are often coated on the outside with
a varnish which is impervious to wet, while within
they, or the parts they enclose, are thickly clothed
with down or wool ; not really to keep out the cold
of winter, which will of course penetrate the bud in
time, but to shield the interior against sudden changes
from warm to cold, or from cold to warm, which are
equally injurious. Scaly buds commonly belong, as would be expect-
ed, to trees and shrubs of northern climates ; while naked buds are
usual in tropical regions, as well as in herbs everywhere which
branch during the summer's growth and do not endure the winter.
45. But naked buds, or nearly naked, also occur in several of oui
own trees and shrubs ; sometimes pretty large ones, as those of Hob
FIG. 49. Annual shoot of the Shagbark Hickory.
FIG. 50. Bud and leaf of the Buttonwood, or American Plane-tree.
LESSON 4.] GROWTH OF PLANTS FROM BUDS. 23
blebush (while those of the nearly-related Snowball or High Bush-
Cranberry are scaly) ; but more commonly, when naked buds occur
in trees and shrubs of our climate, they are small, and sunk in the
bark, as in the Sumac ; or even partly buried in the wood until they
begin to grow, as in the Honey-Locust.
46. Vigor Of Vegetation from Buds, Large and strong buds, like those
of the Horsechestnut, Hickory, and the like, on inspection will be
found to contain several leaves, or pairs of leaves, ready formed,
(bided and packed away in small compass, just as the seed-leaves
are packed away in the seed : they even contain all the blossoms of
the ensuing season, plainly visible as small buds. And the stems
npon which these buds rest are filled with abundant nourishment,
which was deposited the summer before in the wood or in the bark.
Under the surface of the soil, or on it, covered with the fallen leaves
of autumn, we may find similar strong buds of our perennial herbs,
in great variety ; while beneath are thick roots, rootstocks, or tubers,
charged with a great store of nourishment for their use. As we
regard these, \ve shall readily perceive how it is that vegetation
shoots forth so vigorously in the spring of the year, and clothes the
bare and lately frozen surface of the soil, as well as the naked
boughs of trees, almost at once with a covering of the freshest
green, and often with brilliant blossoms. Everything was prepared,
and even formed, beforehand : the short joints of stem in the bud
have only to lengthen, and to separate the leaves from each other
so that they may unfold and grow. Only a small part of the vege-
tation of the season comes directly from the seed, and none of the
earliest vernal vegetation. This is all from buds which have lived
through the winter.
47. This growth from buds, in manifold variety, is as interesting
a subject of study as the growth of the plantlet from the seed, and
is still easier to observe. We have only room here to sketch the
general plan ; earnestly recommending the student to examine at-
tentively their mode of growth in all the common trees and shrubs,
when they shoot forth in spring. The growth of the terminal bud
prolongs the stem or branch: the growth of axillary Luds pro-
duces branches.
48. The Arrangement Of Branches is accordingly the same as of
axillary buds ; and the arrangement of these buds is the same as
that of the leaves. Now leaves are arranged in two principal ways :
they are either opposite or alternate. Leaves are opposite when
24 GROWTH OF PLANTS FROM BUDS. [LESSON 4.
there are two borne on the same joint of stem, as in the Horse-
chestnut, Maple (Fig. 7), Honeysuckle (Fig. 132), Lilac, &c. ; the
two leaves in such cases being always opposite each other, that is,
on exactly opposite sides of the stem. Here of course the buds
in their axils are opposite, as we observe in Fig. 48, where the
leaves have fallen, but their place is shown by the scars. And the
branches into which the buds grow are likewise opposite each other
in pairs.
49. Leaves are alternate when there is only one from each joint of
stem, as in the Oak (Fig. 22), Lime-tree, Poplar, Buttonwood (Fig.
50), Morning-Glory (Fig. 8), not counting the seed-leaves, which of
course are opposite, there being a pair of them ; also in Indian Corn
(Fig. 42), and Iris (Fig. 44). Consequently the axillary buds are
also alternate, as in Hickory (Fig. 49) ; and the branches they
form alternate, making a different kind of spray from the other
mode, one branch shooting on the one side of the stem and the
next on some other. For in the alternate arrangement no leaf is
on the same side of the stem as the one next above or next
below it.
50. Branches, therefore, are arranged with symmetry ; and the
mode of branching of the whole tree may be foretold by a glance at
the arrangement of the leaves on the seedling or stem of the first
year. This arrangement of the branches according to that of the
leaves is always plainly to be recognized ; but the symmetry of
branches is rarely complete. This is owing to several causes ;
mainly to one, viz. :
51. It never happens that all the buds grow. If they did, there
would be as many branches in any year as there were leaves the
year before. And of those which do begin to grow, a large portion
perish, sooner or later, for want of nourishment or for want of light.
Those which first begin to grow have an advantage, which they are
apt to keep, taking to themselves the nourishment of the stem, and
starving the weaker buds.
52. In the Horsechestnut (Fig. 48), Hickory (Fig. 49), Mag-
nolia, and most other trees with large scaly buds, the terminal bud
is the strongest, and has the advantage in growth, and next in
strength are the upper axillary buds: while the former continues
the shoot of the last year, some of the latter give rise to branches,
while the rest fail to grow. In the Lilac also, the upper axillary
buds are stronger than the lower ; but the terminal bud rarely
LESSON 4.] GROWTH OF PLANTS FROM BUDS. 25
appears at all ; in its place the uppermost pair of axillary buds grow,
and so each stem branches every year into two ; making a re-
peatedly two-forked ramification.
53. In these and many similar trees and shrubs, most of the shoots
make a definite annual growth. That is, each shoot of the season
develops rapidly from a strong bud in spring, a bud which gen-
erally contains, already formed in miniature, all or a great part of the
leaves and joints of stem it is to produce, makes its whole growth
in length in the course of a few weeks, or sometimes even in a few
days, and then forms and ripens its buds for the next year's similar
rapid growth.
54. On the other hand, the Locust, Honey-Locust, Sumac, and,
among smaller plants, the Rose and Raspberry, make an indefinite
annual growth. That is, their stems grow on all summer long,
until stopped by the frosts of autumn or some other cause ; con-
sequently they form and ripen no terminal bud protected by scales,
and the upper axillary buds are produced so late in the season
that they have no time to mature, nor has the wood time to solidify
and ripen. Such stems therefore commonly die at the top in winter,
or at least all their upper buds are small and feeble ; and the growth
of the succeeding year takes place mainly from the lower axillary
buds, which are more mature. Most of our perennial herbs grow
in this way, their stems dying down to the ground every year : the
part beneath, however, is charged with vigorous buds, well pro-
tected by the kindly covering of earth, ready for the next year's
vegetation.
55. In these last-mentioned cases there is, of course, no single
main stem, continued year after year .in a direct line, but the trunk
is soon lost in the branches ; and when they grow into trees, these
commonly have rounded or spreading tops. Of such trees with
deliquescent stems, that is, with the trunk dissolved, as it were,
into the successively divided branches, the common American Elm
(Fig. 54) furnishes a good illustration.
56. On the other hand, the main stem of Pines and Spruces, as
it begins in the seedling, unless destroyed by some injury, is carried
on in a direct line throughout the whole growth of the tree, by the
development year after year of a terminal bud : this forms a single,
uninterrupted shaft, an excurrent trunk, which can never be con-
founded with the branches that proceed from it. Of such spiry or
spire-shaped trees, the Firs or Spruces are the most perfect and
3
26 GROWTH OF PLANTS FROM BUDS. [LESSON 4.
familiar illustrations (Fig. 54) ; but some other trees with strong
terminal buds exhibit the same character for a certain time, and
in a less marked degree.
57. Latent Buds, Some of the axillary buds grow the following
year into branches ; but a larger number do not (51). These do not
necessarily die. Often they survive in a latent state for some years,
visible on the surface of the branch, or are smaller and concealed
under the bark, resting on the surface of the wood : and when at
any time the other buds or branches happen to be killed, these older
latent buds grow to supply their place ; as is often seen when the
foliage and young shoots of a tree are destroyed by insects. The
new shoots seen springing directly out of large stems may sometimes
originate from such latent buds, which have preserved their life for
years. But commonly these arise from
58. Adventitious Buds, These are buds which certain shrubs and
trees produce anywhere on the surface of the wood, especially where
it has been injured. They give rise to the slender twigs which often
feather so beautifully the sides of great branches or trunks of our
American Elms. They sometimes form on the root, which naturally
is destitute of buds ; and they are sure to appear on the trunks and
roots of Willows, Poplars, and Chestnuts, when these are wounded
or mutilated. Indeed Osier- Willows are pollarded, or cut off, from
time to time, by the cultivator, for the purpose of producing a crop of
slender adventitious twigs, suitable for basket-work. Such branches,
being altogether irregular, of course interfere with the natural sym-
metry of the tree (50). Another cause of irregularity, in certain
trees and shrubs, is the formation of what are called
59. Accessory OF Supernumerary Buds, There are cases where two,
three, or more buds spring from the
axil of a leaf, instead of the single
one which is ordinarily found there.
Sometimes they are placed one over
the other, as in the Aristolochia or
Pipe- Vine, and in the Tartarian
Honeysuckle (Fig. 51) ; also in the
si Honey-Locust, and in the Walnut and
Butternut (Fig. 52), where the upper supernumerary bud is a good
way out of the axil and above the others. And this is here stronger
FIG. 51. Tartarian Honeysuckle, with three accessory buds in one axil.
LESSON 4.] GROWTH OF PLANTS FROM BUDS.
27
than the others, and grows into a branch which is considerably out 01
the axil, while the lower and smaller ones commonly do not grow at
all. In other cases the three buds stand side by side
in the axil, as in the Hawthorn, and the Red Mapl
(Fig. 53). If these were all to grow into branches,
they would stifle or jostle each other. But some
of them are commonly flower-buds : in
the Red Maple, only the middle one is
a leaf-bud, and it does not grow until
after those on each side of it have ex-
panded the blossoms they contain.
60. Sorts Of Buds, It may be useful
to enumerate the kinds of buds which
have now been mentioned, referring
back to the paragraphs in which the pe-
culiarities of each are explained. Buds,
then, are either terminal or lateral.
They are
Terminal when they rest on the apex
of a stem (42). The earliest terminal
bud is the plumule of the embryo (16).
Lateral, when they appear on the
side of a stem : of which the only
regular kind is the
Axillary (43), namely, those which are situated in
the axils of leaves.
Accessory or Supernumerary (59), when two or more
occur in addition to the ordinary axillary bud. 53
Adventitious (58), when they occur out of the axils and without
order, on stems or roots, or even on leaves. Any of these kind*
may be<, either
Naked, when without coverings; or scaly, when protected by
scales (44, 45).
Latent, when they survive long without growing, and commonly
without being visible externally (57).
Leaf-buds, when they contain leaves, and develop into a leafy
shoot.
Flower-buds, when they contain blossoms, and no leaves, as the
FIG. 52. Butternut branch, with accessory buds, the uppermost above the axil.
FIG. 53. Red-Maple branch, with accessory buds placed side by side.
28 MORPHOLOGY OF ROOTS. [LESSON 5.
side-buds of the Red-Maple, or when they are undeveloped blossoms,
These we shall have to consider hereafter.
Figure 54 represents a spreading-topped tree (American Elm),
the stem dividing otf into branches ; and some spiiy trees (Spruces
on the right hand, and two of the Arbor- Vitae on the left) with ex-
current siems.
LESSON V.
MORPHOLOGY (1.6. VARIOUS SORTS AND FORMS) OF ROOTS.
61. MoFpholOgV as the name (derived from two Greek words)
denotes, is the doctrine of forms. In treating of forms in plants, the
botanist is not confined to an enumeration or description of the
shapes or sorts that occur, which would be a dull and tedious
business. but he endeavors to bring to view the relations between
one form and another ; and this is an interesting study.
62. Botanists give particular names to all the parts of plants, and
also particular terms to express their principal varieties in form.
They use these terms with great precision and advantage in describ-
ing the species or kinds of plants. They must therefore be defined
and explained in our books. But it would be a great waste of time
LESSON 5.] MORPHOLOGY OF ROOTS. 29
for the young student to learn them by rote. The student should
rather consider the connection between one form and another ; and
notice how the one simple plan of the plant, as it has already been
illustrated, is worked out in the greatest variety of ways, through the
manifold diversity of forms which each of its* three organs of vege-
tation root, stem, and leaf is made to assume.
63. This we are now ready to do. That is, having obtained a
g neral idea of vegetation, by tracing the plant from the seed and
the bud into the herb, shrub, or tree, we proceed to contemplate the
principal forms under which these three organs occur in different
plants, or in different parts of the same plant ; or, in other words, to
study the morphology of the root, stem, and leaves.
64. Of these three organs, the root is the simplest and the least
varied in its modifications. Still it exhibits some widely different
kinds. Going back to the beginning, we commence with
65. The Simple Primary Root, which most plants send down from
the root-end of the embryo as it grows from the seed ; as we havf
seen in the Maple (Fig 5 - 7), Morning-Glory (Fig. 8 and 28),
Beech (Fig. 14, 15), Oak and Buckeye (Fig. 22-24), &c. This,
if it goes on to grow, makes a main or tap root, from which aide-
branches here and there proceed. Some plants keep this maii> root
throughout their whole life, and send off only small side bra' <;hes ;
as in the Carrot (Fig. 58) and Radish (Fig. 59) : and in some trees,
like the Oak, it takes the lead of the side-branches for many years,
unless accidentally injured, as a strong tap-root. But commonly
the main root divides off very soon, and is lost in the branches.
We have already seen, also, that there may be at the beginning
66. Multiple Primary Roots, We have noticed them in the Pump-
kin (Fig. 10), in the Pea (Fig. 20), and in Indian Corn (Fig. 42).
That is, several roots have started all at once, or nearly so, from the
seedling stem, and formed a bundle or cluster (a fascicled root, as
it is called), in place of one main root. The Bean, as we observe
in Fig. 18, begins with a main root , but some of its branches soon
overtake it, and a cluster of roots is formed.
67. Absorption of Moisture by Roots, The branches of roots as they
grow commonly branch again and again, into smaller roots or rootlets ;
in this way very much increasing the surface by which the plant
connects itself with the earth, and absorbs moisture from it. The
whole surface of the root absorbs, so long as it is fresh and new ;
and the newer the roots and rootlets are, the more freely do they
3*
30
MORPHOLOGY OF ROOTS.
[LESSON 5.
imbibe. Accordingly, as long as the plant grows above ground, and
expands fresh foliage, from which moisture much of the time largely
escapes into the air, so long it continues to extend and multiply its
roots in the soil beneath, renewing and increasing the fresh surface
for absorbing moisture, in proportion to the demand from above.
And when growth ceases above ground, and the leaves die and fall,
or no longer act, then the roots generally stop growing, and their
soft and tender tips harden. From this period, therefore, until
growth begins anew the next spring, is the best time for transplant-
ing ; especially for trees and shrubs, and herbs so large that they
cannot well be removed without injuring the roots very mnch.
68. We see, on considering a moment, that an herb or a tree
consists of two great surfaces, with a narrow part or trunk between
them, one surface spread out in the air, and the other in the soil.
These two surfaces bear a certain proportion to each other ; and the
upper draws largely on the lower for
moisture. Now, when the leaves fall
from the tree in autumn, the vast sur-
face exposed to the air is reduced to a
very small part of what it was before ;
and the remainder, being covered with
a firm bark, cannot lose much by evap-
oration. In common herbs the whole
surface above ground perishes in au-
tumn ; and many of the rootlets die at
the same time, or soon afterwards.
So that the living vegetable is reduced
for the time to the smallest compass,
to the thousandth or hundred-thou-
sandth part of what it was shortly
before, and what remains alive rests
in a dormant state, and may now be
transplanted without much danger of
harm. If any should doubt whether
there is so great a difference between
the summer and the winter size of
56 plants, let them compare a lily-bulb
with the full-grown Lily, or calculate the surface of foliage which
FIG. 55. Seedling Maple, of the natural size, showing the root-hairs. 56. A bit of the
n4 of the root magnified.
LESSON 5.]
MORPHOLOGY OF ROOTS.
31
a tree exposes to the air, as compared with the surface of its
twigs.
69. The absorbing surface of roots is very much greater than
it appears to be, on account of the root-hairs,
or slender fibrils, which abound on the fresh and
new parts of roots. These may be seen with
an ordinary magnifying-glass, or even by the
naked eye in many cases ; as in the root of a
seedling Maple (Fig. 55), where the surface is
thickly clothed with them. They are not root-
lets of a smaller sort ; but, when more magnified,
are seen to be mere elongations of the surface
of the root into slender tubes, which through
their very delicate walls imbibe moisture from
the soil with great avidity. They are com-
monly much longer than those shown in Fig.
56, which represents only the very tip of a root
moderately magnified. Small as they are indi-
vidually, yet the whole amount of absorbing
surface added to the rootlets by the countless
numbers of these tiny tubes is very great.
70. Roots intend-
ed mainly for ab-
sorbing branch free-
ly, and are slender
or thread-like. When the root is prin-
cipally of this character it is said to be
fibrous ; as in Indian Corn (Fig. 42),
and other grain, and to some extent in
all annual plants (41).
71. The Root as a Storehouse of Food,
In biennial and many perennial herbs
(41), the root answers an additional
purpose. In the course of the season it
becomes a storehouse of nourishment,
and enlarges or thickens as it receives
the accumulation. Such roots are said
to be fleshy ; and different names are applied to them according to
PTO. 57 58. 59. Forms of fleshy or thickened roots.
32
MORPHOLOGY OF ROOTS.
[LESSON 5.
their shapes. We may divide them all into two kinds ; 1st, those
consisting of one main root, and 2d, those without any main root.
72. The first are merely different shapes of the tap-root ; which is
Conical, when it thickens most at the crown, or where it joins
the stem, and tapers regularly downwards to a point, as in the
Common Beet, the Parsnip, and Carrot (Fig. 58) :
Turnip-shaped or napiform, when greatly thickened above ; but
abruptly becoming slender below ; as the Turnip (Fig. 57) : and,
Spindle-shaped, or fusiform, when thickest in the middle and
tapering to both ends ; as the common Radish (Fig. 59).
73. In the second kind, where there
is no main root, the store of nourishing
matter may be distributed throughout
the branches or cluster of roots gener-
ally, or it may be accumulated in some
of them, as we see in the tuberous roots
of the Sweet Potato, the common Peony,
and the Dahlia (Fig. 60).
74. All but the last of these illustra-
trations are taken from biennial plants.
These grow with a large tuft of leaves
next the ground, and accumulate nour-
ishment all the first summer, and store
up all they produce beyond what is
wanted at the time in their great root,
which lives over the winter. We know
Tery well what use man and other animals make of this store of food,
in the form of starch, sugar, jelly, and the like. From the second
year's growth we may learn what use the plant itself makes of it.
The new shoots then feed upon it, and use it to form with great
rapidity branches, flower-stalks, blossoms, fruit, and seed ; and, having
used it up, the whole plant dies when the seeds have ripened.
75. In the same way the nourishment contained in the separate
tuberous roots of the Sweet Potato and the Dahlia (Fig 60) is fed
upon in the spring by the buds of the stem they belong to ; and
as they are emptied of their contents, they likewise die and decay.
But meanwhile similar stores of nourishment, produced by the second
year's vegetation, are deposited in new roots, which live through the
FIG. 60. Clustered tuberous toots of the Dahlia, with the bottom of the stem they
belong to.
LESSON 5.] MOItPHOLOGY OF ROOTS. 33
next winter, and sustain the third spring's growth, and so on ;
these plants being perennial (41), or lasting year after year, though
each particular root lives little more than one year.
76. Many things which commonly pass for roots are not really
roots at all. Common potatoes are tuberous parts of stems, while
sweet potatoes are roots, like those of the Dahlia (Fig. CO). The dif-
ference between them will more plainly appear in the next Lesson. ;
77. Secondary Roots, So far we have considered only the original
or primary root, that which proceeded from the lower end of the
first joint of stem in the plantlet springing from the seed, and its
subdivisions. We may now remark, that any other part of the stem
will produce roots just as well, whenever favorably situated for it;
that is, when covered by the soil, which provides the darkness and
the moisture which is congenial to them. For these secondary roots,
as they may be called, partake of the ordinary disposition of the
organ : they avoid the light, and seek to bury themselves in the,
ground. In Indian Corn we see roots early striking from the second
and the succeeding joints of stem under ground, more abundantly
than from the first joint (Fig. 42). And all stems that keep up a
connection with the soil such as those which creep along on or
beneath its surface are sure to strike root from almost every joint.
So will most branches when bent to the ground, and covered with
the soil : and even cuttings from the branches of most plants can be
made to do so, if properly managed. Propagation by buds depends
upon this. That is, a piece of a plant which has stem and leaves,
either developed or in the bud, may be made to produce roots, and
so become an independent plant.
78. In many plants the disposition to strike root is so strong, that
they even will spring from the stem above ground. In Indian Corn,
for example, it is well known that roots grow, not only from all those
joints round which the earth is heaped in hoeing, but also from those
several inches above the soil : and other plants produce them from
stems or branches high in the air. Such roots are called
79. Aerial Roots, All the most striking examples of these are met
with, as we might expect, in warmer and damper climates than ours,
and especially in deep forests which shut out much of the light ; this
being unfavorable to roots. The Mangrove of tropical shores, which
occurs on our own southern borders ; the Sugar Cane, from which,
roots strike just as in Indian Corn, only from higher up the stem ;
the Pandauus, called Screw Pine (not from its resemblance to a
S&F 3
34 MORPHOLOGY OF ROOTS [LESSON 5.
Pine-tree, but because it is like a Pine-apple plant) ; and the famous
Banyan of India, and some other Fig-trees, furnish the most remark-
able examples of roots, which strike from the stem or the branches
in the open air, and at length reach the ground, and bury them-
selves, when they act in the same manner as ordinary roots.
80. Some of our own common plants, however, produce small
aerial rootlets ; not for absorbing nourishment, but for climbing. By
these rootlets, that shoot out abundantly from the side of the stems
and branches, the Trumpet Creeper, the Ivy of Europe, and our
Poison Rhus, here called Poison Ivy, fasten themselves firmly
to walls, or the trunks of trees, often ascending to a great height.
Here roots serve the same purpose that tendrils do in the Grape-
Vine and Virginia Creeper. Another form, and the most aerial of
all roots, since they never reach the ground, are those of
81. Epiphytes, or Air-Plants, These are called by the first name
(which means growing on plants), because they are generally found
upon the trunks and branches of trees ; not that they draw any
nourishment from them, for their roots merely adhere to the bark,
and they flourish just as well upon dead wood or any other con-
venient support. They are called air-plants because they really
live altogether upon what they get from the air, as they have no
connection with the soil. Hundreds of air-plants grow all around
us without attracting any attention, because they are small or hum-
ble. Such are the Lichens and Mosses that abound on the trunks
or boughs of trees, especially on the shaded side, and on old walls,
fences, or rocks, from which they obtain no nourishment. But this
name is commonly applied only to the larger, flower-bearing plants
which live in this way. These belong to warm and damp parts of
the world, where there is always plenty of moisture in the air. The
greater part belong to the Orchis family and to the Pine- Apple
family ; and among them are some of the handsomest flowers known.
We have two or three flowering air-plants in the Southern States,
though they are not showy ones. One of them is an Epidendrum
growing on the boughs of the Great-flowered Magnolia : another is
the Long- Moss, or Black Moss, so called, although it is no Moss
at all, which hangs from the branches of Oaks and Pines in all
the warm parts of the Southern States. (Fig 61 represents both
of these. The upper is the Epidendrum conopseum ; the lower, the
Black Moss, Tillandsia usneoides.)
82. Parasitic Plants exhibit roots under yet another remarkable
LESSON 5.J
MORPHOLOGY OF ROOTS.
85
aspect. For these are not merely fixed upon other plants, as air-
plants are, but strike their roots, or what answer to roots, into them,
and feed on their juices. Not only Moulds and Blights (which are
plants of very low organization) live in this predacious way, but
many flowering herbs, and even shrubs. One of the latter is the
Mistletoe, the seed of which germinates on the bough of the tree
where it falls or is left by birds ; and the forming root penetrates the
/bark and engrafts itself into the wood, to which it becomes united as
' firmly as a natural branch to its parent stem ; and indeed the parasite
lives just as if it were a branch of the tree it grows and feeds on.
A most common parasitic herb is the Dodder; which abounds in
low grounds everywhere in summer, and coils its long and slender
leafless, yellowish stems resembling tangled threads of yarn
round and round the stalks of other plants ; wherever they touch
piercing the bark with minute and very shorfr rootlets in the form of
suckers, which draw out the nourishing juices of the plants laid hold
of. Other parasitic plants, like the Beech-drops and Pine-sap, fasten
their roots under ground upon the roots of neighboring plants, and
rob them of their rich juices.
36 MORPHOLOGY OF STEMS AND BRANCHES. [LESSON 6.
LESSON VI.
MORPHOLOGY OF STEMS AND BRANCHES.
83. THE growth of the stem in length, and the formation of
branches, have been considered already. Their growth in thick-
ness we may study to more advantage in a later Lesson. The very
various forms which they assume will now occupy our attention,
beginning with
84. The Forms of Stems and Branches above ground, The principal
differences as regards size and duration have been mentioned before
(41); namely, the otyious distinction of plants into herbs, shrubs,
and trees, which depends upon the duration and size of the stem.
The stem is accordingly
Herbaceous, when it dies down to the ground every year, or after
blossoming.
Suffrutescent, when the bottom of the stem above the soil is a
little woody, and inclined to live from year to year.
Suffruticose, when low stems are decidedly woody below, but
herbaceous above.
Fruticose, or shrubby, when woody, living from year to year, and
of* considerable size, not, however, more than three or four times
the height of a man.
Arborescent, when tree-like in appearance, or approaching a tree
in size.
Arboreous, when forming a proper tree trunk.
85. When the stem or branches rise above ground and are ap-
parent to view, the plant is said to be caulescent (that is, to have a
caulis or true stem). When there is no evident stem above ground,
but only leaves or leaf-stalks and flower-stalks, the plant is said to
be acaulescent, i. e. stemless, as in the Crocus, Bloodroot, common
Violets, &c., and in the Beet, Carrot, and Radish (Fig. 59), for the
first season. There is a stem, however, in all such cases, only it
remains on or beneath the ground, and is sometimes very short.
Of course leaves and flowers do not arise from the root. These
concealed sorts of stem we will presently study.
86. The direction taken by stems, &c., or their mode of growth,
LESSON 6.] SUCKERS, STOLONS, AND OFFSETS. -37
gives rise to several terms, which may be briefly mentioned:
such as
Diffuse, when loosely spreading in all directions.
Declined, when turned or bending over to one side.
Decumbent, reclining on the ground, as if too weak to stand.
Assurgent or ascending, when rising obliquely upwards.
Procumbent or prostrate, lying flat on the ground from the first. ,
Creeping, or repent, when prostrate stems on or just beneath the
ground strike root as they grow ; as does the White Clover, the
little Partridge-berry, &c.
Climbing, or scandent, when stems rise by clinging to other ob-
jects for support, whether by tendrils, as do the Pea, Grape-
Vine, and Virginia Creeper (Fig. 62) ; by their twisting leaf-stalks,
as the Virgin's Bower ; or by rootlets, like the Ivy, Poison Ivy, and
Trumpet Creeper (80).
Twining, or voluble, when stems rise by coiling themselves spirally
around other stems or supports ; like the Morning-Glory and the Bean.
87. Certain forms of stems have received distinct names. The
jointed stem of Grasses and Sedges is called by botanists a culm ;
and the peculiar scaly trunk of Palms and the like (Fig. 47) is
sometimes called a caudex. A few forms of branches the gardener
distinguishes by particular names ; and they are interesting from
their serving for the natural propagation of plants from buds, and
for suggesting ways by which we artificially multiply plants that
would not propagate themselves without the gardener's aid. These
are suckers, offsets, stolons, and runners.
88. Slickers are ascending branches rising from stems under ground,
such as are produced so abundantly by the Rose, Raspberry, and
other plants said to multiply " by the root." If we uncover them,
we see at once the great difference between these subterranean
branches and real roots. They are only creeping branches under
ground. Remarking how the upright shoots from these branches
become separate plants, simply by the dying off of the connecting
under-ground stems, the gardener expedites the result by cutting
them through with his spade. That is, he propagates the plant " by
division."
89. Stolons are trailing or reclining branches above ground, which
strike root where they touch the soil, and then send up a vigorous
shoot, which has roots of its own, and becomes an independent plant
when the connecting part dies, as it does after a while. The Currant
4
38 MORPHOLOGY OF STEMS A.ND BRANCHES. |_LESSON (X
and the Gooseberry naturally multiply in this way, as well as by
suckers (which we see are just the same thing, only the connecting
part is concealed under ground). They must have suggested the
operation of layering, or bending down and covering with earth
branches which do not naturally make stolons ; and after they have
taken root, as they almost always will, the gardener cuts through
the connecting stem, and so converts a rooting branch into a sepa-
rate plant.
90. Offsets, like those of the Houseleek, are only short stolons,
with a crown of leaves at the end.
91. Runners, of which the Strawberry presents the most familiar
example, are a long and slender, tendril-like, leafless form of creep-
ing branches. Each runner, after having grown to its full length ?
strikes root from the tip, and fixes it to the ground, then forms a bud
there, which develops into a tuft of leaves, and so gives rise to a new
plant, which sends out new runners to act in the same way. In this
manner a single Strawberry plant will spread over a large space, or
produce a great number of plants, in the course of the summer ; all
connected at first by the slender runners -, but these die in the
following winter, if not before, and leave the plants as so many
separate individuals.
92. Tendrils are branches of a very slender sort, like runners, not
destined like them for propagation, and therefore always destitute
of buds or leaves, but intended for climbing. Those of the Grape-
Yine, of the Virginia Creeper (Fig. 62), and of the Cucumber and
FIG, 62. Piece of the stem of Virginia Creeper, bearing a leaf and a tendril. 63. Tips
of a tendril, about the natural size, showing the disks by which they hold fast to walls, &,c.
LESSON 6.] RUNNERS, TENDRILS, SPINES. 89
Squash tribe are familiar illustrations. The tendril commonly grows
straight and outstretched until it reaches some neighboring support,
such as a stem, when its apex hooks around it to secure a hold ?.
then the whole tendril shortens itself by coiling up spirally, and so
draws the shoot of the growing plant nearer to the supporting object.
When the Virginia Creeper climbs the side of a building or the
smooth bark of a tree, which the tendrils cannot lay hold of in the
usual way, their tips expand into a flat disk or sucker (Fig. 62. 63),
which adheres very firmly to the wall or bark, enabling the plant to
climb over and cover such a surface, as readily as the Ivy does by
means of its sucker-like little rootlets. The same result is effected
by different organs, in the one case by branches in the form of ten-
drils ; in the other, by roots.
93. Tendrils, however, are not always branches ; some are leaves,
or parts of leaves, as those of the Pea (Fig. 20). Their nature in
each case is to be learned from their position, whether it be that of
a leaf or of a branch. In the same way
94. Spines OF Thorns sometimes represent leaves, as in the Bar-
berry, where their nature is shown by their situation outside of an
axillary bud or branch. In other words, here they have a bud in
their axil, and are therefore leaves ; so we shall have to mention
them in another place. Most commonly spines are stunted and
hardened branches, arising from the axils of leaves, as in the Haw-
thorn and Pear. A neglected Pear-tree or Plum-tree shows every
gradation between ordinary branches and thorns. Thorns sometimes
branch, their branches partaking of the same spiny character : in
this way those on the trunks of Honey- Locust trees (produced from
adventitious buds, 58) become exceedingly complicated and horrid.
The thorns on young shoots of the Honey-Locust may appear some-
what puzzling at first view ; for they are situated some distance
above the axil of the leaf. Here the thorn comes from the upper-
most of several supernumerary buds (59). Prickles, such as those
of the Rose and Blackberry, must not be confounded with thorns:
these have not the nature of branches, and have no connection with
the wood ; but are only growths of the bark. When we strip off
the bark, the prickles go with it.
95. Still stranger forms of stems and branches than any of these
are met with in some tribes of plants, such as Cactuses (Fig. 76).
These will be more readily understood after we have considered
some of the commoner forms of
40 MORPHOLOGY OF STEMS AND BRANCHES. [LESSON 6.
96. Subterranean Stems and Branches, These are very numerous
and various ; but they are commonly overlooked, or else confounded
with roots. From their situation they are out of the sight of the
superficial observer : but if sought lor and examined, they will well
repay the student's attention. For the vegetation that is carried on
under ground is hardly less varied, and no less interesting and im,
portant, than that which meets our view above ground. All their
lorms may be referred to four principal kinds ; namely, the Rhizo-
ma or Rootstock, the Tuber, the Corm, and the Bulb.
97. The RootstOCk, or Rhizoma, in its simplest form, is merely a
creeping stem or branch (80) growing beneath the surface of the
soil, or partly covered by it. Of this kind are the so-called creeping,
running, or scaly roots, such as those by which the Mint (Fig. 64),
the Scotch Rose, the Couch-grass or Quick-grass, and many other
plants, spread so rapidly and widely, " by the root," as it is said.
That these are really stems, and not roots, is evident from the way
in which they grow; from their consisting of a succession of joints;
and from the leaves which they bear on each joint (or node, as
the botanist calls the place from which leaves arise), in the form of
small scales, just like the lowest ones on the upright stem next the
ground. Like other stems, they also produce buds in the axils of
these scales, showing the scales to be leaves ; whereas real roots
bear neither leaves nor axillary buds. Placed, as they are, in the
damp and dark soil, such stems naturally produce roots, just as the
creeping stem does where it lies on the surface of the ground ; but
the whole appearance of these roots, their downward growth, and
their mode of branching, are very different from that of the subter-
ranean stem they spring from.
98. It is easy to see why plants with these running rootstocks take
such rapid and wide possession of the soil, often becoming great
pests to farmers, and why they are so hard to get rid of. They are
FIG. 64. Rootstocks, or creeping subterranean branches, of the Peppermint.
LESSON 6.] SUBTERRANEAN FORMS : ROOTSTOCKS. 41
always perennials (41) ; the subterranean shoots live over the first
winter, if not longer, and are provided with vigorous buds at every
joint. Some of these buds grow in spring into upright stems, bearing
foliage, to elaborate the plant's crude food into nourishment, and at
length produce blossoms for reproduction by seed ; while many oth-
ers, fed by nourishment supplied from above, form a new generation
of subterranean shoots ; and this is repeated over and over in the
course of the season or in succeeding years. Meanwhile as the sub-
terranean shoots increase in number, the older ones, connecting the
series of generations into one body, die off year by year, liberating
the already rooted side-branches as so many separate plants ; and
so on indefinitely. Cutting these running rootstocks into pieces,
therefore, by the hoe or the plough, far from destroying the plant,
only accelerates the propagation ; it converts one many-branched
plant into a great number of separate individuals. Even if you
divide the shoots into as many pieces as there are joints of stem,
each piece (Fig. 65) is already a plantlet, with its roots and with a
bud in the axil of its scale-like leaf (either latent or apparent), and
having prepared nourishment enough in the bit of
stem to develop this bud into a leafy stem ; and so
a single plant is all the more speedily converted
into a multitude. Such plants as the Quick-
grass accordingly realize the fable of the Hy-
dra ; as fast as one of its many branches is cut K
off, twice as many, or more, spring up in its stead. Whereas, when
the subterranean parts are only roots, cutting away the stem com-
pletely destroys the plant, except in the rather rare cases where the
root produces adventitious buds (58).
99. The more nourishment rootstocks contain, the more readily do
separate portions, furnished with buds, become independent plants.
It is to such underground stems, thickened with a large amount of
starch, or some similar nourishing matter stored up in their tissue,
that the name of rhizoma or rootstock is commonly applied ; such,
for example, as those of the Sweet Flag or Calamus, of Ginger, of Iris
or Flower-de-luce (Fig. 133), and of the Solomon's Seal (Fig. 66).
100. The rootstocks of the common sorts of Iris of the gardens
usually lie on the surface of the ground, partly uncovered ; and
they bear real leaves (Fig. 133), which closely overlap each other;
FFG. 65. A piece of the running rootstock of the Peppermint, with its node or joint, and
an axillary bud ready to grow.
A. *
42 MORPHOLOGY OF STEMS AND BRANCHES. [LESSON 6.
the joints (i. e. the internodes, or spaces between each leaf) being
very short. As the leaves die, year by year, and decay, a scar
left in the form of a ring marks the place where each leaf was
attached. Instead of leaves, rootstocks buried under ground com-
monly bear scales, like those of the Mint (Fig. 64), which are im-
perfect leaves.
101. Some rootstocks are marked with large round scars of a
different sort, like those of the Solomon's Seal (Fig. 66), which gave
this name to the plant, from their looking something like the impres-
sion of a seal upon wax. Here the rootstock sends up every spring
an herbaceous stalk or stem, which bears the foliage and flowers,
and dies in autumn ; and the seal is the circular scar left by the
death and separation of the dead stalk from the living rootstock.
As but one of these is formed each year, they mark the limits of a
year's growth. The bud at the end of the rootstock in the figure,
which was taken in summer, will grow the next spring into the stalk
of the season, which, dying in autumn, will leave a similar scar, while
another bud will be formed farther on, crowning the ever-advancing
summit or growing end of the stem.
102. As each year's growth of stem, in all
these cases, makes its own roots, it soon becomes
independent of the older parts. And after a
certain age, a portion dies off behind, every
year, about as fast as it increases at the grow-
ing end ; death following life with equal and
certain step, with only a narrow interval be-
tween. In vigorous plants of Solomon's Seal
or Iris, the living rootstock is several inches or
a foot in length ; while in the short rootstock of
FIG. 66. Rootstock of Solomon's Seal, with the bottom of the stalk of the season, and th
*ud for the next year's growth.
FIG. 67. The very short rootstock and bud of a Trillium or Birthroot.
LESSON 6.] SUBTERRANEAN FORMS : TUBERS.
43
Trillium or Birthroot (Fig. 67) life is reduced to a very narrow-
span, only an inch or less intervening between death beneath and
young life in the strong bud annually renewed at the summit.
103. A Tuber is a thickened portion of a rootstock. When slender
subterranean branches, like those of the Quick-grass or Mint (Fig.
64), become enlarged at the growing end by the accumulation there
of an abundance of solid nourishing matter, tubers are produced, like
those of the Nut-grass of the Southern States (which accordingly be-
comes a greater pest even than the Quick-grass), and of the Jerusalem
Artichoke, and the Potato. The whole formation may be seen at a
glance in Figure 68, which represents the subterranean growth of a
Potato-plant, and shows the tubers in all their stages, from shoots
jti-t beginning to enlarge at the tip, up to fully-formed potatoes.
And Fig. 69, one of the forming tubers moderately magnified,
plainly shows the leaves of this thickening shoot, in the form of little
scales. It is under these scales that the eyes appear (Fig. 70) :
and these are evidently axillary buds (43).
104. Let us glance for a moment at the economy or mode of life
of the Potato-plant, and similar vegetables, as shown in the mor-
FIG, 68. Forming tubers of the Potato. 69. One of the very young potatoes, moderately
magnified. 70- Slice of a portion through an eye, more magnified.
44 MORPHOLOGY OF STEMS AND BRANCHES. [LESSON 6.
phology of the branches, that is, in the different forms they appear
under, and the purposes they serve. The Potato-plant has three
principal forms of branches: 1. Those that bear ordinary leaves,
expanded in the air, to digest what they gather from it and what
the roots gather from the soil, and convert it into nourishment.
2. After a while a second set of branches at the summit of the
plant bear flowers, which form fruit and seed out of a portion of the
nourishment which the leaves have prepared. 3- But a larger part
of this nourishment, while in a liquid state, is carried down the stem,
into a third sort of branches under ground, and accumulated in the
form of starch at their extremities, which become tubers, or deposi-
tories of prepared solid food; just as in the Turnip, Carro!,
Dahlia, &c. (Fig. 57 - 60), it is deposited in the root. The use
of the store of food is obvious enough. In the autumn the whole
plant dies, except the seeds (if it formed them) and the tubers ; and
the latter are left disconnected in the ground. Just as that small
portion of nourishing matter which is deposited in the seed (3, and
Fig. 34) feeds the embryo when it germinates, so the much larger
portion deposited in the tuber nourishes its buds, or eyes, when they
likewise grow, the next spring, into new plants. And the great
supply enables them to shoot with a greater vigor at the beginning,
and to produce a greater amount of vegetation than the seedling
plant could do in the same space of time ; which vegetation in turn
may prepare and store up, in the course of a few weeks or months,
the largest quantity of solid nourishing material, in a form most
available for food. Taking advantage of this, man has transported
the Potato from the cool Andes of South America to other cool cli-
mates, and makes it yield him a copious supply of food, especially in
countries where the season is too short, or the summer's heat too
little, for profitably cultivating the principal grain-plants.
105. All the sorts of subterranean stems or branches distinguished
by botanists pass into one another by gradations. We have seen
how nearly related the tuber is to the rootstock, and there are many
cases in which it is difficult to say which is the proper name to use.
So likewise,
10G. Til form, OF Solid Bulb, like that of the Indian Turnip and
the Crocus (Fig. 71), is just a very short and thick rootstock; as
will be seen by comparing Fig. 71 with Fig. 67. Indeed, it grows
so very little in length, that it is often much broader than long, as
in the Indian Turnip, and the Cyclamen of our greenhouses. Corms
LESSON 6.]
SUBTERRANEAN FORMS : BULBS.
45
are usually upright, producing buds on their upper surface and
roots from the lower. But (as \ve see in the Crocus here figured)
buds may shoot from just above any of the faint cross lines or
rings, which are the scars left b
