Erythronium. Erythronium americanum Ker. Scrofula Root. Yellow Snowdrop. Rattlesnake Violet. Dogtooth Violet. Yellow Adder's Tongue.—This is an indigenous, perennial, liliaceous plant, sometimes called, after the European species, dog's-tooth violet. It grows in rich woods from New Brunswick to Florida and west to Ontario and Arkansas. It flowers in the latter part of April or early in May. All parts of it are active. In the dose of twenty or thirty grains (1.3 or 2.0 Gm.) the recent bulb is emetic. The leaves are said to be more powerful. The activity of the plant is diminished by drying.