Description from Flora of China
Rhizome short. Culms 45-100 cm tall, acutely trigonous, firm, clothed at base with purple bladeless sheaths. Leaves shorter than culm, blades broadly linear, 5-7 mm wide, flat, margins scabrous. Involucral bracts sheathless, lowest bracts shortly bladed, shorter than inflorescence, scabrous on margins, upper ones setaceous. Spikes 4-6, approximate; terminal spike gynaecandrous; lateral spikes female with a few male flowers at base, densely many flowered, oblong-cylindric, 1.5-3.5 cm; lowest peduncle (ca. 2 mm) slender, pendulous. Female glumes dark purple, elliptic-lanceolate, 4-4.5 mm, margins narrowly white hyaline, apex acuminate. Utricles stramineous, subequaling glume, compressed, sometimes upper yellow-brown or purple punctate, nerveless, apex abruptly contracted into a short beak, orifice 2-toothed. Nutlets loosely enveloped, oblong or obovate-oblong, trigonous, ca. 2 mm; stigmas 3. Fl. and fr. Jul-Sep.
● Alpine meadows in thickets, lakesides, wet grasslands; 3400-4600 m. Gansu, Qinghai, Shaanxi, W Sichuan, E Xizang, NW Yunnan.