Cyperus

Stems are solitary or tufted, triangular or less often circular in cross-section, solid, usually leafless for most of their length, the culm base sometimes swollen. Leaves are usually at the base of the plant, 3-ranked, linear and grass-like, the lower ones often scale-like, flat, V-, or inversely W-shaped in cross section, without ligules, with closed sheaths. Inflorescence is terminal, 1st order umbellate to capitate (congested into a dense head), 2d order with spicate or digitately arranged spikelets, rarely a solitary spikelet. Inflorescence is subtended by 1-22 spirally arranged leaf-like bracts. Spikelets are 1-many-flowered. Glumes are arranged in two rows (distichous). Perianth is absent. Stamens are 1-3. Stigmas are 2-3. Fruit is a small 3-sided or lenticular achene.