DOG'S-TOOTH VIOLET, the name given to a genus (Erytlironium) of beautiful plants of the lily family (Liliaceae) comprising about 15 species, all, except one, North American. They are low herbs with unbranched stems which spring from deep corms and bear near the surface of the ground a pair of unequal leaves, often mottled with dark splotches, and large, nodding, lily-like, mostly solitary flowers on slender stalks. The European dog's-tooth violet (E. dens-canis), the only Old World species, a delicate spring-bloomer, with rose-purple flowers, is planted in borders and rockeries. The best known representative in eastern North America is the yellow dog's tooth violet (E. americanum), known also as yellow adder's-tongue and trout lily, with yellow flowers, in. to 14 in. long, on stalks 6 in. to 8 in. high. This handsome spring wild flower is native to moist woods from Nova Scotia to Minnesota and southward to Florida and Arkansas. The similar but smaller white dog's-tooth violet (E. albidum), called also white adder's-tongue, with white flowers, occurs in low woodlands from Ontario to Minnesota and south ward to Georgia and Texas. A conspicuous species in the Rocky Mountain region is the large-flowered dog's-tooth violet or glacier lily (E. grandiflorum), with flower-stalks 8 in. to 16 in. tall, bear ing 1 to 5 yellow flowers 1 in. to 2 in. long. The avalanche lily (E. montanum), common in alpine meadows in Washington and Ore gon, is a smaller plant with white flowers.