Section VI. STEMS.
[88.] 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. These do not bear leaves, in the common sense; yet they bear rudiments of leaves, or what answers to leaves, although not in the form of foliage. The so-called stemless or acaulescent plants are those which bear no obvious stem (caulis) above ground, but only flower-stalks, and the like.
[89.] Stems above ground, through differences in duration, texture, and size, form herbs, shrubs, trees, etc., or in other terms are
Herbaceous, dying down to the ground every year, or after blossoming.
Suffrutescent, slightly woody below, there surviving from year to year.
Suffruticose or Frutescent, when low stems are decidedly woody below, but herbaceous above.
Fruticose or Shrubby, 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 mode of growth, or approaching a tree in size.
Arboreous, when forming a proper tree-trunk.