Perennial, caulescent, rhizomatous herbs with fasciculate, fibrous roots, sometimes stoloniferous, rarely with rounded tubers. Leaves radical, equitant, linear or ensiform, strongly laterally compressed (Iris-like), with an open or closed amplexicaulous, sheathing base, closely striate-nerved or plicate-nerved. Flowers ♀♂, in Mal. spp. actinomorphic, paniculate. Perianth-segments 6, 2-seriate, free. Stamens 3, epipetalous; filaments ± free; anthers 2-celled, basifixed or versatile, introrse, splitting lengthwise. Ovary superior to inferior, 3-celled. Style simple, usually filiform, stigma punctiform. Ovules ~ to 2 per cell, on axile placentas. Capsule loculicid, 3-valved. Seeds with abundant endosperm and a small embryo, often flat, sometimes winged. Distr. About 9 or 16 genera, mainly in Australia, less in S. Africa and N. and tropical America, in Malaysia one native sp. of an otherwise Australian genus and one American ornamental.