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 root of a plant is that portion which is usually found in the earth, the stem and leaves being in the air. The point of union is called the collar or neck of the plant.
A fibrous root is one composed of many spreading branches, as that of barley.
A conical root is one where it tapers regularly from the crown to the apex, as that of the carrot.
A fusiform root is one when it tapers up as well as down, as that of the radish.
A napiform root is one when much swollen at the base, so as to become broader than long, as that of the turnip.
A fasciculated root is one when some of the fibres or branches are thickened.
A tuberiferous root is one when some of the branches assume the form of rounded knobs, as that of the potato.
A palmate root is one when these knobs are branched.
Aerial roots are those emitted from the stem into the open air, as that of Indian corn.
A rhizome, or root stock, is a prostrate stem either subterranean or resting on the surface, as that of calamus, or blood-root.
A tuber is an enlargement of the apex of a subterranean branch of the root, as that of the common potato or artichoke.
A cormus is a fleshy subterranean stem of a round or oval figure, as in the Indian turnip.
A bulb is an extremely abbreviated stem clothed with scales, as that of the lily.