This section of the book is from "The Complete Herbalist" by Dr. O. Phelps Brown. Also available from Amazon: The Complete Herbalist: The People Their Own Physicians By The Use Of Nature's Remedies.
The stem is that portion of the plant which grows in an opposite direction from the root, seeking the light, and exposing itself to the air. All flowering plants possess stems. In those which are said to be stemless, it is either very short, or concealed beneath the ground.
An herb is one in which the stem does not become woody, but dies down to the ground at least after flowering.
A shrub is a woody plant, branched near the ground, and less than five times the height of man.
A tree attains a greater height, with a stem unbranched near the ground.
The stem of a tree is usually called the trunk; in grasses it has been termed the culm.
Those stems which are too weak to stand erect are said to be decombent, procumbent, and prostrate.
A stolon in a form of a branch which curves or falls down to the ground, where they often strike root.
A sucker is a branch of subterraneous origin, which, after running horizontally and emitting roots in its course, at length rises out of the ground and forms an erect stem, which soon becomes an independent plant, as illustrated by the rose, raspberry, etc.
A runner is a prostrate, slender branch sent off from the base of the parent stem.
An offset is a similar but shorter branch, with a tuft of leaves at the end, as in the houseleek.
A spine is a short and imperfectly developed branch of a woody plant, as exhibited in the honey-locust.
A tendril is commonly a slender leafless branch, capable of coiling spirally, as in the grape vine.