Perennial or sometimes annual herbs, usually of moist places. Stems tufted or from creeping or erect rootstocks, mostly simple, terete or compressed. Leaves alternate, sheathing, grasslike, flat to terete. Inflorescence usually compound or decompound, paniculate, corymbose or umbelloid, rarely reduced to 1 flower. Flowers borne singly and each subtended by a bractlet, or in headlike or spikelike clusters and not individually subtended; inflorescence usually subtended by 1 or more bracts. Perianth small, regular 6-parted into 3 outer and 3 inner glumaceous segments. Stamens usually 3 or 6; anthers adnate, introrse, 2-celled. Ovary superior, 3- or 1-celled, with 3-many ovules, 1 style, 3 filiform stigmas. Fruit a loculicidal capsule, 3-many seeded; seeds small, round to elongate, with fleshy endosperm. Eight genera, perhaps 300 species, widely distributed. (Munz, Flora, So. Calif. 908).