. Introduction to structural and systematic botany, and vegetable physiology. Botany. EOOTSTOCKS AND TUBKRS. 107 nearly in contact (Fig. 167). In the very short and slow-growing rootstock of Trillium (Fig. 169), the base of the leaf-bearing and flowering stem of the season surrounds and coYers the terminal bud. In our common Dentaria or Toothwort, and in Ilydrophyllum, the base of this annual stalk or of the leafstalks partakes in the thicken- ing, and persists as a part of the rhizoma, in the form of fleshy scales or tooth-shaped processes. In other scaly rootstocks, these persist- ent bases
. Introduction to structural and systematic botany, and vegetable physiology. Botany. EOOTSTOCKS AND TUBKRS. 107 nearly in contact (Fig. 167). In the very short and slow-growing rootstock of Trillium (Fig. 169), the base of the leaf-bearing and flowering stem of the season surrounds and coYers the terminal bud. In our common Dentaria or Toothwort, and in Ilydrophyllum, the base of this annual stalk or of the leafstalks partakes in the thicken- ing, and persists as a part of the rhizoma, in the form of fleshy scales or tooth-shaped processes. In other scaly rootstocks, these persist- ent bases of the leaves are thin, and more like bud-scales, and slowly decay after a year or two. All such markings are vestiges of leaves, &c., or the scars from which they have fallen or decayed away, and indicate the nodes. They show that the body that bears them belongs to the stem; and not to the root, which is wholly leafless. Root-stocks branch, just as other stems do, by the development of lateral buds from the axils of their scales or leaves. They serve as a reservoir of nourishing matter, for the maintenance of the an- nual growth, in the same manner as do thickened roots (14o, 146). When such subterranean stems are thickened at the apex only, they produce 189. A Tuber. This is usually formed by the enlargement of the growing bud of a subterranean branch, and the deposition of starch,. &c. in its tissue. This deposit serves for the nourishment of the buds (eyes) which it involves, when they develop the following year. The common Potato offers the most familiar example; and it is FIG. 170. Base of tlie stem of the Jerusalem Artichoke (Helianthus tuberosus), with its tubers. FIG. 171. A monstrous branch or bud of the Potato, above ground, showing a tiansition to the tuber, (From the Gardener's Chronicle.). Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustra
Size: 1852px × 1350px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorgra, bookcentury1800, bookdecade1850, booksubjectbotany
