Herbs, perennial, rarely annual [or shrubs with woody caudex], evergreen or seasonal, sometimes cespitose; rootstock a rhizome, bulb, or corm. Flowering stems aerial (or subterranean in Romulea), simple or branched, terete or variously compressed, angled or winged. Leaves basal and cauline, distichous; proximal 2–3 sometimes membranous, not reaching much above ground; others with open or closed sheaths, usually unifacial [bifacial or terete], oriented edgewise to the stem; blade parallel-veined, plane or pleated, channeled. Inflorescences umbellate, monochasial cymes (rhipidia), spikes, or solitary flowers; rhipidia enclosed in 2, opposed, usually large, leafy to dry bracts (spathes); flowers except for the first subtended by 1 floral bract; spike flowers each subtended by 2, opposed bracts. Flowers usually pedicellate [± sessile]; per-ianth actinomorphic or zygomorphic, petaloid, with 2 equal or unequal whorls of 3 tepals each [1 whorl of 6]; tepals usually large, showy, distinct or connate in tube; stamens 3 [2], inserted at base of outer tepals or in tube, symmetrically arranged or unilateral, arcuate [declinate]; filaments distinct or partly to completely connate, sometimes weak, unable to support anthers; anthers with 2 pollen sacs, extrorse, occasionally latrorse, usually dehiscing longitudinally [rarely apically]; ovary inferior [superior in Tasmanian Isophysis], 3-locular [1-locular]; placentation axile [parietal]; ovules 2–few, anatropous; style single, filiform at least proximally, usually 3-branched or 3-lobed, branches either filiform, distally expanded, sometimes each divided in distal 1/2, stigmatic toward apices, or branches thickened, or flattened, petaloid, stigmas then abaxial below apices. Fruits capsular, loculicidal, rarely indehiscent, firm to cartilaginous, occasionally woody. Seeds globose to angular (prismatic) or discoid, sometimes broadly winged; seed coat usually dry (rarely fleshy); endosperm hard, with reserves of hemicellulose, oil, and protein; embryo small.