Rhizome short, ligneous. Culms tufted, 25-80 cm tall, slightly thick, obtusely trigonous, smooth, bearing rather many leaves at base. Leaves shorter than or equaling culm, blades 4-8 mm wide, flat, scabrous on veins of upper surface and margins of top; lower sheaths up to 6 cm, reddish brown. Involucral bracts leaflike, longer than or slightly shorter than inflorescence, sheathed, sheathing mouth concave. Spikes 4-7, lowermost spaced up to 10 cm, uppermost 2 ± contiguous; terminal spike male, linear, 1-5.5 cm; remaining spikes female, linear-cylindric, 2-12 cm, loosely many flowered; peduncles slender, slightly pendulous. Female glumes brownish yellow, ovate, ca. 3.5 mm, membranous, 1-veined, margins white hyaline, upper margin praemorse, apex acute, mucronate or muticous. Utricles brownish green, suberect, longer than glume, elliptic-lanceolate, trigonous, 5-7 mm, membranous, glabrous, shiny, 2 lateral veins elevated, base attenuate, shortly stipitate, apex gradually narrowed to a long beak, beak ca. 2.5 mm. Nutlets tightly enveloped, narrowly elliptic, trigonous, ca. 2.5 mm; stigmas 3. Fl. and fr. Jun-Jul.

Forests, streamsides, roadsides, grasslands at watersides; 2000-3000 m. S Gansu, Sichuan, Taiwan, Yunnan [Bhutan, India, Indonesia (Sumatra), Nepal, New Guinea].