Herbs, perennial; rhizome usually stoloniferous. Culms tufted or sparse, lateral or central, erect, trigonous, bladeless sheathed at base. Leaves basal or basal and cauline, flat, rarely involute or revolute on margins, linear or lorate, rarely lanceolate, sheathed at base. Involucral bracts leaflike, rarely scale-shaped or setaceous, sheathed or not. Flowers unisexual, 1 male flower or 1 female flower in a unisexual spikelet, female spikelet included by prophyll, prophyll wholly connate at margins into utricle, sometimes reduced spikelet axis present in utricle, with scalelike bractlet at base. Spikes 1 to numerous, usually numerous spikes arranged in spicate, racemose, or paniculate inflorescence, composed of many unisexual or bisexual spikes, bisexual spike androgynous or gynaecandrous, usually plants monoecious, rarely dioecious, pedunculate or sessile, with or without sheathlike or utriculiform cladoprophyll at base; male flower with (2 or)3 stamens, filaments distinct; female flower with 1 pistil, style slightly slender, persistent or deciduous, base usually not thickened; stigmas 2 or 3. Utricles trigonous, plano-convex or biconvex, with slightly long or short beak. Nutlets rather tightly or loosely enveloped in utricle, trigonous or plano-convex.

Taxa incertae sedis

Carex aristata R. Brown var. lanceisquama Handel-Mazzetti, Symb. Sin. 7: 1270. 1936.

No specimens were seen by the present authors. The type is from NW Yunnan.

Carex esquirolii H. Léveillé & Vaniot, Bull. Soc. Bot. France 53: 315. 1906.

No specimens were seen by the present authors. The plant, a member of Carex subg. Vignea, cannot be confidently associated with any known species based on the description. The type is from Guizhou.

Carex polycephala Boott var. simplex Kükenthal in Handel-Mazzetti, Symb. Sin. 7: 1268. 1936.

No specimens were seen by the present authors. The type is from Yunnan.

About 2,000 species: cosmopolitan; 527 species (260 endemic) in three subgenera and 69 sections (two endemic) in China.

(Authors: Dai Lunkai (戴伦凯), Liang Songyun (梁松筠 Liang Song-jun), Zhang Shuren (张树仁), Tang Yancheng (汤彦承 Tang Yen-cheng); Tetsuo Koyama, Gordon C. Tucker)