Perennial herbs with rhizomes or corms, leaves and flowers annual; roots sometimes tuberous. Leaves cauline, distichous, alternate or subopposite to verticillate, sessile or subpetiolate, usually sheathing; venation parallel, rarely with reticulate secondary venation. Inflorescence a terminal raceme or cyme, sometimes umbellate, spike-like or flowers solitary. Flowers bisexual, rarely unisexual, actinomorphic to slightly zygomorphic; perianth segments 6(–12), free or fused in lower half; stamens 6, dorsifixed, dehiscing extrorsely by longitudinal slits, rarely latrorsely to introrsely; ovary superior 3(–4)-locular, completely or partially fused with axile placentation; ovules few to many per locule; styles 1–3(–4), styles and stigmas often minute. Fruit a dry or fleshy septicidal or loculicidal capsule, rarely berry-like; seeds subglobose or ovoid to subangular, sometimes with an aril.
About 18 genera and 284 species, more or less world-wide except South America; 9 genera and c. 42 species (3 naturalised) in Australia, 4 genera in Victoria.