Annuals or perennials; culms erect or ascending. Ligule membranous, sometimes ciliate; blade linear. Inflorescence a branched panicle, the primary branches solitary, simple or branched at base, the branches often in whorls, usually bearing only one terminal triad of spikelets. Spikelets in triads, 2 pedicelled and 1 sessile, sometimes with another 1 or 2 pairs of spikelets below the triad, one of the pair pedicelled, one sessile; rachis very obliquely articulate below the triads. Sessile spikelet laterally compressed; glumes subcoriaceous, with nerves less distinct on outer side of spikelet; lower glume glossy, often with spiny tubercles, with inrolled margins, back rounded, or conduplicate and keeled upwards; upper glume usually keeled, sometimes awned; lemmas shorter, membranous; lower lemma 2-nerved; lower palea wanting; upper lemma entire, 2-toothed, or 2-lobed, usually with a geniculate awn from apex; upper palea wanting or small; hyaline and nerveless; lodicules 2, small, cuneate, glabrous; stamens 3 ; ovary glabrous, the styles 2, free, the stigmas exserted laterally near base. Caryopsis narrowly oblong, laterally compressed; embryo 1 J2 as long as caryopsis. Pedicelled spikelet often different in color from the sessile ones, dorsally compressed, barren or sometimes staminate; pedicels slender, pressed against the slightly longer sessile spikelets, not glossy.
About 2 species distributed in the tropical and subtropical regions, especially in the Old World;.
One cosmopolitan species C. aciculatus is found very commonly in Taiwan.