Ascle'pias incarna'ta, Swamp Milkweed. -- The root (rhizome), U.S.P. 1820-1830, 1840-1850, 1870; Canada, United States. Perennial herb, smooth or pubescent, .6-1 M. (2-3 degrees) high, with 2 downy lines above; very leafy; leaves lanceolate, cordate base, 10-17.5 Cm. (4-7') long, 2.5-5 Cm. (1-2') wide; flowers rose-purple, sweet-scented; root 2.5 Cm. (1') long, knotty, oblong, brownish, bark thin, central pith, sweet, then acrid bitter, emits milky uice when wounded; contains volatile oil, 2 acrid resins, asclepiadin. Alterative, emetic, cathartic, diuretic, like Asclepias tuberosa; decoction, infusion, tincture. Dose, gr. 15-40 (1-2.6 Gm.).