454. ASCLEPIAS TUBEROSA (N.F.).—The root of Ascle'pias tubero'sa Linné. Off. in U.S.P. 1890. Enters the market in transverse or longitudinal sections about 20 mm. (4/5 in.) in thickness, and of various lengths; externally pale orange-brown or grayish, wrinkled longitudinally; internally it consists of a grayish or yellowish porous wood with broad, white medullary rays; fracture tough, uneven, showing the two distinct layers of the thin bark, the inner one white; odorless; taste bitter, somewhat acrid. Diaphoretic expectorant. Dose: 15 to 60 gr. (1 to 4 Gm.). Fl'ext., off. U.S.P. 1890. dose: 15 to 60 drops (1 to 4 mils).
455. ASCLEPIAS CORNUTI Decaisne.—COMMON SILK-WEED or MILK-WEED. (Rhizome.) Cylindrical sections, from 6 to 25 mm. (1/4 to 1 in.) thick, beset with a few simple rootlets; externally grayish-brown, finely wrinkled, and rough from stem-scars and undeveloped branches. It breaks with a short or splintery fracture, showing a thick bark containing lactiferous vessels, and a yellowish, porous wood in narrow wood-wedges. Odorless; taste bitter and nauseous. Diuretic, alterative, and expectorant; recommended in pectoral affections and in dropsy. Dose: 15 to 60 gr. (1 to 4 Gm.), in decoction.
456. ASCLEPIAS INCARNATA Linné.—SWAMP MILK-WEED. Habitat: North America. An oval or globular, yellowish-brown rhizome, with a tough, white wood, and a central pith; rootlets smooth, light yellowish-brown, brittle; odorless; taste sweetish, bitter, and acrid. It contains an emetic principle, asclepiadin; it is also alterative and cathartic. Dose: 15 to 45 gr. (1 to 3 Gm.).