Erect or ascending, unbranched perennial herbs with scaly bulb. Roots fibrous. Leaves numerous, cauline, alternate, opposite or verticillate. Inflorescence a terminal raceme, spike, racemose umbel or flowers single. Flowers bisexual, often rather large; perianth segments free or at least partly united albeit rather tenuosly, equal or subequal; stamens 6, anthers dorsifixed or basifixed, dehiscing introrsely by slits; ovary superior, cylindric, 3-locular, ovules numerous; style elongate, stigma capitate, 3-lobed or trifid. Fruit a loculicidal capsule; seeds numerous, winged.
About 75 species, in temperate regions of the Northern Hemisphere, widely cultivated; at least 2 species naturalised in Australia.