Bulbous, non-odorous, perennial herbs. Roots fibrous or fleshy. Leaves annual, basally tufted, linear, exuding milky latex when broken. Inflorescence a scapose, terminal umbel enclosed by 2 overlapping bracts; flowers bisexual; perianth segments equal, shortly united basally; stamens 6, filaments free, broadly linear, anthers dorsifixed, dehiscing introrsely; ovary superior; ovules 4–12 per locule; style terminal on ovary. Fruit a membranous capsule; seeds angular, black.
Species number varies depending on authority, from 19 to 87, native to America; 1 naturalised in Australia.