. Introduction to structural and systematic botany, and vegetable physiology. Botany. besides, the interminable subterranean branches bear tubers, or reservoirs of nutritive matter, in their course, which have still greater powers of vitality, as they contain a copious store of food for the development of the buds they bear. The name of 188. Rhizoma or RootstOCk is apphed in a general way to all these perennial, horizontally elongated, more or less subterranean, root- like forms of the stem; and more particu- larly to those that are consid- erably thick- ened by the ac- 188 cumulation of starc
. Introduction to structural and systematic botany, and vegetable physiology. Botany. besides, the interminable subterranean branches bear tubers, or reservoirs of nutritive matter, in their course, which have still greater powers of vitality, as they contain a copious store of food for the development of the buds they bear. The name of 188. Rhizoma or RootstOCk is apphed in a general way to all these perennial, horizontally elongated, more or less subterranean, root- like forms of the stem; and more particu- larly to those that are consid- erably thick- ened by the ac- 188 cumulation of starch or other forms of nutritive matter in their tissue, such as the so-called roots of Ginger, of the Iris or Flower-de-luce (Fig. 291), of the Calamus or Sweet Flag, and of the Blood- root. They grow after the manner of ordinary stems, advancing from year to year by the annual development of a bud at the apex, and emitting roots from the under side of the whole surface; thus established, the older portions die and decay, as coiTesponding additions are made to the opposite growing extremity. Each year's growth is often marked, as in some species of Iris (Fig. 291), by a narrowing at the place where the growth of the season is suspended, followed by an enlargement where it recom- mences ; or else, as in the curious Diphylleia of the Alleghany Mountains (Fig. 1C7), and the Polygonatum or Solomon's Seal (Fig. 168), it is more indelibly stamped by an im- pressed circular scar (which has been likened to the impression of a seal), left annually, in autumn, by the death and separation from the perennial rootstoek of the herbaceous stalk of the season which bore the foliage and blossoms. In Diphylleia the growth is so slow, and the ascending stems so thick, that the scars of successive years are. FIG. 168. Rootstock of Polygonatum or Solomon's Seal, with the terminal bud, the base of the stalk of the season, and three scars from "which the latter has separated in as many former year
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Keywords: ., bookauthorgra, bookcentury1800, bookdecade1850, booksubjectbotany
