Infl. a solitary, terminal, erect, few- to many-fld spikelet, without a subtending bract at base. Glumes us. spirally imbricate, lowermost 1–2 often sterile and different in shape from the rest, uppermost also often sterile. Fls hermaphrodite. Per. of 0–10 hypog. bristles. Stamens 1, 2 or 3. Style 3- or 2-fid. Nut obovoid to orbicular, biconvex to triquetrous, crowned by the persistent enlarged base of the style. Annual or perennial lfless herbs, stout or slender, often rhizomatous, the culms produced in tufts or in a linear series, each culm bearing 1 or more lf-sheaths and a cluster of roots at base. A cosmopolitan genus of c. 200 spp. Of the 5 N.Z. spp., 1 is endemic, the rest occur also in Australia.