Perennials, evergreen and rhizomatous. Leaves mostly basal, equitant, usually erect and ensiform. Inflorescence with the scape erect, simple or with 1 or 2 branches. Primary bracts herbaceous, usually leaf-like, sheathing the flower clusters, with shorter membranous secondary bracts separating the flowers. Inner and outer perianth segments abruptly narrowed basally and united to form a tube, sepals spreading or deflexed, usually larger and showier than petals, petals erect to spreading or slightly recurved; stamens free, inserted on perianth tube, anthers basifixed, linear; ovary ovoid-trigonous; style branches 3, broad, petaloid, often emarginate or distinctly bilobed, arched over outer perianth and appressed to stamens, stigmas transverse, exceeded by prominent bifid crests. Capsule ovoid to clavate, more or less trigonous, exserted from the primary bracts; seeds few, large, globose to angular.
About 300 species from the Northern Hemisphere. Many species cultivated and many hybrids known (both in the wild and in horticulture). A dozen or so species naturalised to varying extents in Australia.