Description from Flora of China
Rhizome stoloniferous. Culms 15-60 cm tall, slender, trigonous, scabrous, clothed at base with castaneous-brown sheaths disintegrating into fibers. Leaves shorter than culm, blades linear, 2-3 mm wide, flat, margins scabrous. Involucral bracts setaceous, shorter than inflorescence. Spikes 3 or 4; terminal spike male, oblong-cylindric to cylindric, 1-2 cm, with peduncle 3-6 mm; lateral spikes female, oblong or oblong-cylindric to cylindric, 8-20 × 4-5 mm, densely many flowered, lowest with peduncle 3-7 mm, others subsessile. Female glumes blackish purple, oblong, ca. 2.5 mm, with light midrib, margins narrowly white hyaline, apex obtuse. Utricles light brown below, blackish above, equaling glume, elliptic or ovate-elliptic, plano-convex, ca. 2.5 mm, densely minutely papillose, nerveless, apex abruptly contracted into a short beak, orifice truncate. Nutlets yellowish, tightly enveloped, broadly obovate, ca. 1.5 mm; style base not thickened; stigmas 2. Fl. and fr. Jul-Aug.
Slopes, grasslands, moist places; 2000-3500 m. Gansu, Ningxia, Qinghai, Xinjiang, Xizang [Mongolia, Russia].