Erythro'nium america'num, Yellow Adder's- Tongue. -- The root and herb, U.S.P. 1820-1850; United States. Perennial herb, scape 15.-22.5 Cm. (6-9') high, slender, leaves 2, pale green, equal length 12.5 Cm. (5'), one twice as wide as the other, brown-spotted, flowers yellow, 2.5-5 Cm. (1-2') long, root (bulb or corm) solid, brown; inside white. All parts of the plant active; used like colchicum. Dose, gr. 20-30 (1.3-2 Gm.) in infusion. Large doses emetic.