Annual or perennial herbs, with rhizomes and scapes. Leaves mostly basal, linear, sheathing at the base. Flowers small, in terminal bractless spikes or racemes or some borne singly in the axils of the leaves; flowers perfect or imperfect, anemophilous. Perianth segments 3 or 6, in 1 or 2 series, greenish or reddish, or perianth none. Stamens 6, 4 or 3 or 1; anthers subsessile, 2-celled, extrorse. Carpels 6, 4, or 3 or 1, superior, free or connate; style short to absent; ovule 1, basal. Fruit cylindrical to obovoid; seeds without endosperm. Several genera, mostly in cooler parts of both hemispheres. (Munz, Flora So. Calif. 916).