Rhizome woody. Culms lateral, 20-80 × 0.1-0.3 cm, trigonous, base with leafless pale brown sheaths. Leaves basal and cauline; basal leaves tufted, longer or shorter than culms, elliptic to elliptic-linear, 10-35 × 2-5 cm, glabrous on both surfaces or scabrid or densely hairy abaxially, sometimes with transverse veins, base attenuate, apex acuminate; petiole up to 30 cm, glabrous, sometimes leaf base extending downward forming narrow wings; cauline leaves brown, spathelike, papery, glabrous. Involucral bracts spathelike, with blades, usually shorter than inflorescence branches. Panicle compound, 3- to several branched; inflorescence branches paniculate, single or binate, triangular-ovate, 2-3.5 × 1.5-3 cm; peduncles of inflorescence branches rigid, trigonous, 4-8 cm, densely pubescent; inflorescence axes sharply trigonous, densely pubescent; bractlets brownish white with deep brown spots, glumelike, lanceolate, 4-5 mm. Spikes 10-20, bisexual, androgynous, arising from flowerless utriculiform cladoprophylls, patent, oblong-cylindric, 5-14 mm; male part of spike linear-lanceolate, usually shorter than female part, fewer flowered; female part 2-7-flowered; male glumes pale brown, ovate-lanceolate, 3-3.5 mm, membranous; female glumes brown laterally, yellowish green with brown spots and 3 veins at middle, ovate, 2-2.5 mm, membranous, margins ciliate when young, apex acuminate. Utricles pale yellowish green with dense brown spots, elliptic, trigonous, 3-4 mm, papery, with 2 lateral veins abaxially, glabrous, subsessile, apex contracted gradually into beak of medium length, beak slightly shorter than 1/2 length of utricle, orifice emarginate. Nutlets brown at maturity, elliptic, trigonous, 1.5-2.2 mm; style base not or slightly thickened; stigmas 3.

Forests, watersides, shady slopes, cliffs, valleys; 200-1500 m. Fujian, Guangdong, Guangxi, Guizhou, Hunan, Jiangxi, Sichuan, Yunnan, Zhejiang [Vietnam].