Herbs, perennial or rarely annual. Rhizomes short. Culms terete. Leaves basal or cauline; sheath reddish brown; leaf blade flat, 3-angled, or semiterete. Involucral bracts leaflike, sheathing. Inflorescences paniculate, racemose, or rarely headlike. Spikelets usually narrowly ovoid or oblong-ovoid, usually 1-4-flowered, basal 1 or 2 flowers usually bisexual, apical 1 or 2 flowers male. Glumes dark colored with whitish margin, distichous, usually papery, deciduous, 1-veined, keeled, basal 2 or 3 empty. Perianth bristles 6 or absent. Stamens 3. Style slender; stigmas 3. Nutlet ellipsoid or obovoid, usually terete, 3-sided, or rarely biconvex, smooth or with reticulate ornamentation. More than 120 species: mostly in Australia, a few in E and SE Asia, Pacific islands (New Caledonia, New Zealand), Europe, and America; four species (one endemic) in China.