The root of

Asclepias tuberosa.

Characters. - Root large and fusiform, dried in longitudinal or transverse sections; from one to six inches (25 to 150 millimetres) long, and about three quarters of an inch (two centimetres) or more in thickness; the head knotty, and slightly but distinctly annulate, the remainder longitudinally wrinkled; externally orange-brown, internally whitish; tough and having an uneven fracture; bark thin, and in two distinct layers, the inner one whitish; wood yellowish, with large, white medullary rays; it is inodorous, and has a bitterish, somewhat acrid taste; when long kept it acquires a grey colour.

Composition. - It contains resins and an odorous fatty matter.

Dose. - 20-60 gr.

Use. - It may be used as a diaphoretic or expectorant. In large doses it acts as an emetic and purgative.

Asclepias Incarnata. White Indian Hemp. Not officinal. America. - The root appears to act like digitalis, strengthening the beats of the heart, and producing diuresis. A fluid extract has been used in doses of 1/2-1 fl. dr. every three hours.