Stem (botany)

“ The Stem is the axis of the plant, the part which bears all the other organs. Branches are secondary stems, that is, stems growing out of stems. The stem at the very beginning produces roots, in most plants a single root from the base of the embryo-stem, or caulicle. As this root becomes a descending axis, so the stem, which grows in the opposite direction is called the ascending axis. Rising out of the soil, the stem bears leaves; and leaf-bearing is the particular characteristic of the stem. But there are forms of stems that remain underground, or make a part of their growth there. ”

“ Stem strictly erect from an annual root, and with the upright or ascending branches wing-angled or grooved; leaves alternate, linear, acute, the upper subulate and glandular-serrulate; a pair of dark glands in place of stipules; sepals ovate-lanceolate and sharp-pointed, strongly 3-nerved and with rough-bristly-glandular margins, scarcely longer than the ovoid-globose incompletely 10-celled pod; styles united almost to the middle.—Dry soils, E. Mass. to Minn., and southwestward.—Flowers and pods twice as large as in the preceding. ”

“ Contrast between Stem and Root. Stems are ascending axes; roots are descending axes. Stems grow by the successive development of internodes (13) , one after another, each leaf-bearing at its summit (or node) ; so that it is of the essential nature of a stem to bear leaves. Roots bear no leaves, are not distinguishable into nodes and internodes, but grow on continuously from the lower end. They commonly branch freely, but not from any fixed points nor in definite order.
69. Although roots generally do not give rise to stems, and therefore do not propagate the plant, exceptions are not uncommon. ”

“ The stem, when seen in transverse section, has its vascular bundles arranged in a ring; in reality, however, they form a kind of cylindrical network in the stem; the bundles are open, and thickening takes place by means of a cambium; annual rings are formed in the perennial stems. There is a rich and very varied form of branching. The two first leaves of a shoot (fore-leaves) are placed nearly always to the right and to the left; the same arrangement is found in the two first leaves developed on the flower-stalk, and these are, as a rule, the only two ”

“ Stems or branches which remain under ground give out roots as freely as roots themselves give off branches. Stems which creep on the ground most commonly root at the joints; so will most branches when bent to the ground, as in propagation by layering; and propagation by cuttings equally depends upon the tendency of the cut end of a shoot to produce roots. Thus, 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. ”

“ The most prominent of these parts are root, stem, leaf, flower, fruit, and seed. Familiar plants differ wonderfully in size and shape,—from fragile mushrooms, delicate waterweeds and pond-scums, to floating leaves, soft grasses, coarse weeds, tall bushes, slender climbers, gigantic trees, and hanging moss.
The Stem Part.—In most plants there is a main central part or shaft on which the other or secondary parts are borne. This main part is the plant axis. Above ground, in most plants, the main plant axis bears the branches, leaves, and flowers; below ground, it bears the roots. ”

“ Stem simple, black-spotted; leaves of three kinds; floating ones becoming very large (41⁄2 by 31⁄2 ́) , roundish-ovate and cordate or ovate-oblong, 25–37-nerved, all alternate; upper submersed ones (3–5) usually lanceolate, acute at base and very long-acuminate, 10–15-nerved, very thin, cellular each side of the midrib, undulate, short-petioled; lowest (2–4 near the base of the stem) thicker, plane, oval or oblong with a rounded base, or spatulate-oblong, on longer petioles; stipules rather short and obtuse; peduncles thicker than the stem ”

“ Any part of the stem may produce them, but they most readily come from the nodes. As a general rule they naturally spring, or may be made to spring, from almost any young stem, when placed in favorable circumstances,—that is, when placed in the soil, or otherwise supplied with moisture and screened from the light. For the special tendency of the root is to avoid the light, seek moisture, and therefore to bury itself in the soil. Propagation by division, which is so common and so very important in cultivation, depends upon the proclivity of stems to strike root. ”

“ It is a property of stems to produce roots. Stems do not spring from roots in ordinary cases, as is generally thought, but roots from stems. When perennial herbs arise from the ground, as they do at spring-time, they rise from subterranean stems.
66. The Primary Root is a downward growth from the root-end of the caulicle, that is, of the initial stem of the embryo (Fig. 5-7, 81) . If it goes on to grow it makes a main or tap-root, as in Fig. 37, etc. Some plants keep this main root throughout their whole life, and send off only small side branches ”

“ The gardener imitates them in the process called layering, that is, bending down an erect branch and covering it with soil, causing it to strike root. When the connecting stem is cut, a new plant is formed. Long and leafless stolons, like those of the Strawberry are called runners. Stems creep below the ground as well as above. Probably the pupil will think of some examples. The pretty little Gold Thread is so named from the yellow running stems, which grow beneath the ground and send up shoots, or suckers, which make new plants. ”

“ As explained in the section on Inflorescence, flowers arise from the same places as branches, and from no other; flower-buds, like leaf-buds, appear either on the summit of a stem, that is, as a terminal bud, or in the axil of a leaf, as an axillary bud. And, as the plan of a symmetrical flower shows, the arrangement of the parts on their axis or receptacle is that of leaves upon the stem.
245. That the sepals and petals are of the nature of leaves is evident from their appearance; they are commonly called the leaves of the flower. ”

“ 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 vegetation of the season comes directly from the seed, and none of the earliest vernal vegetation. ”

“ The pupils should notice that the buds are always just above the large triangular scars. If they are still in doubt as to the cause of these marks, show them some house-plant with well-developed buds in the axils of the leaves, and ask them to compare the position of these buds with their branches. The buds that spring from the inner angle of the leaf with the stem are axillary buds; those that crown the stems are terminal. Since a bud is an undeveloped branch, terminal buds carry, on the axis which they crown, axillary buds give rise to side-shoots. ”

“ Nodes and Internodes.—The parts of the stem at which buds grow are called nodes or joints and the spaces between the buds are internodes. The stem at nodes is usually enlarged, and the pith is usually interrupted. The distance between the nodes is influenced by the vigour of the plant: how?
Fig. 59.—Rhizome or Rootstock.
Stems vs. Roots.—Roots sometimes grow above ground (Chap. VII) ; so, also, stems sometimes grow underground, and they are then known as subterranean stems, rhizomes, or rootstocks (Fig. 59) .
Stems normally bear leaves and buds, and thereby are they distinguished from roots ”

“ Stems are of Many Forms.—The general way in which a plant grows is called its habit. The habit is the appearance or general form. Its habit may be open or loose, dense, straight, crooked, compact, straggling, climbing, erect, weak, strong, and the like. The roots and the leaves are the important functional or working parts; the stem merely connects them, and its form is exceedingly variable. ”

“ The third difference is that, while the stem bears leaves, and has buds normally developed in their axils, roots bear no organs. The stem, however, especially when wounded, may produce buds anywhere from the surface of the bark, and these buds are called adventitious buds. In the same manner, roots occasionally produce buds, which grow up into leafy shoots, as in the Apple and Poplar. ”

“ They are light green on one side, and whitish or gray on the other. Each leaf has its own brown, hairy and hollow stem, on which it sits like a wide hat or a mushroom turned over. The root grows very thick, is white and porous inside, and has a strong, bitter taste. ”

“ They have hollow stems, with partitions at the nodes; the leaves consist only of a whorl of scales at each node, these coalescent into a sheath: from the axils of these leaf-scales, in many species, branches grow out, which are similar to the stem but on a much smaller scale, close-jointed, and with the tips of the leaves more apparent. At the apex of the stem appears the fructification, as it is called for lack of a better term, in the form of a short spike or head. This consists of a good number of stalked shields, bearing on their inner or under face several wedge-shaped spore-cases. ”

“ The root is perennial, thick and woody. Stem very much branched even from the bottom, round, the younger branches angular, and clothed with fine silky down, as are likewise the flower-stalks, corollæ, and backs of the leaves. ”

“ Stem ascending from a creeping base, rigid, very branching, invested by the bases of the leaves and stipules; leaves crowded in two ranks, recurved-spreading, narrow-lanceolate or linear (3–5 ́ long and 2–3 ́ ́ wide) , acuminate, ciliate-serrulate with translucent teeth, many-nerved; stipules obtuse when young, their nerves soon becoming bristles; spikes numerous, loosely few-flowered, on short peduncles ”

“ Stems erect; bracts before flowering conspicuous; racemes densely flowered.
15. D. Canadénse, DC. Stem hairy (3–6° high) ; leaflets oblong-lanceolate or ovate-lanceolate, obtuse, with numerous straightish veins, much longer than the petiole (11⁄2–3 ́ long) ; flowers showy, larger than in any other species (1⁄2–{1/3} ́ long) .—Dry rich woods, N. Brunswick to N. C., Minn., and Kan.
16. D. sessilifòlium, Torr. & Gray. Stem pubescent (2–4° high) ; leaves nearly sessile; leaflets linear or linear-oblong, blunt, thickish, reticulated, rough above, downy beneath; branches of the panicle long ”

“ Pubescent; stem prostrate, rooting at base; leaves short-petioled, obovate-elliptical or wedge-oblong, obtuse, serrate; racemes densely many-flowered; pedicels shorter than the calyx; capsule obovate-triangular, broadly notched.—Dry hills and open woods, N. Eng. to Mich., and southward. July. (Eu., Asia.)
V. Chamæ̀drys, L. Stem pubescent, at least in two lines, ascending from a creeping base; leaves subsessile, ovate or cordate, incisely crenate; racemes loosely-flowered; pedicels little longer than calyx; capsule triangular-obcordate.—Sparingly introduced into Canada, N. Y., and Penn. ”

“ Stems 3–6 ́ ́ long, fleshy, rootlets numerous; fertile branches suberect, clavate; leaves imbricate, often narrower than the stem, subquadrate-ovate, more or less serrate, the sinus and lobes subacute; diœcious; involucral leaves 3, erect, free; perianth broadly oval or subobovate, obtusely and sparingly angled, the apex slightly plicate, the mouth connivent, dentate, sometimes narrowly scarious; capsule oval.—On rotten wood, N. J., Ohio, and Ill.; rare. Our smallest species. ”

“ March–May. Rootstocks often bearing little tubers.—Var. campéstre, Milde, is a not uncommon state, in which the sterile stem bears a small fruiting spike at the summit. (Eu.)
[+] [+] Fertile stems when older producing herbaceous 3-sided branches, and lasting through the summer, except the naked top which perishes after fructification.
2. E. praténse, Ehrh. Sterile and finally also the fertile stems producing simple straight branches; sheaths of the stem with ovate-lanceolate short teeth, those of the branches 3-toothed; stems more slender and the branches shorter than in the last.—Mich. ”

“ The leaves are wanting in many plants, called for that reason plantæ aphyllæ as Salicornia, Engl. Bot. t. and 1691, Stapelia variegata, Curt. Mag. t. 26, glanduliflora, Exot. Bot. t., and all the species of that genus. In such cases the surface of the stem must perform all their necessary functions.
1. With respect to Situation and Position,
Folia radicalia, radical leaves, are such as spring from the root, like those of the Cowslip, Engl. Bot. t., and Anemone Pulsatilla, t..
Caulina, stem-leaves, grow on the stem as in Paris quadrifolia, t., Polemonium cæruleum, t., &c. ”

“ Stamens 5–12, distinct or in 3 clusters; pod 1-celled, with 3 strictly parietal placentæ; styles short, distinct, with capitate stigmas; petals oblong or linear; sepals narrow, erect; slender annuals, with 4-angular branches; flowering all summer.
[*] Stem simple or loosely branched; leaves linear to ovate, spreading.
12. H. mùltilum, L. Stem flaccid, widely branching (6–20 ́ high) ; leaves ovate to narrowly oblong, obtuse, partly clasping, 5-nerved; cymes leafy; flowers 2 ́ ́ broad; pods ovate-conical, rather longer than the calyx.—Low grounds, everywhere. ”

“ Stigma clavate; stem somewhat quadrangular with 2–4 ridges or hairy lines decurrent from some of the leaves.
[+] Tall and mostly branching, many-flowered; leaves rather large, toothed, not revolute, the lower opposite; seeds papillose.
4. E. coloràtum, Muhl. Somewhat hoary-pubescent above or glandular, 1–3° high; leaves lanceolate, sharply serrulate or denticulate, acute, narrowed to conspicuous petioles; flowers pale, more or less nodding; peduncles shorter than the leaves; seeds dark, unappendaged ”