Description from Flora of China
Rhizome short. Culms tufted, 60-90 cm tall, acutely trigonous, scabrous above, clothed at base with purple-brown sheaths often disintegrating into fibers. Leaves shorter than culm, blades linear, 2-4 mm wide, flat, margins scabrous, apex acuminate. Involucral bracts leaflike, lowest one longer than inflorescence. Spikes 4 or 5, approximate; terminal spike gynaecandrous, oblong-cylindric, 1.5-2 cm; lateral spikes female, oblong-cylindric, 2-2.5 cm; peduncle slender, lowest one 2-4 cm, rarely up to 15 cm, becoming shorter upward. Female glumes dark purple, lanceolate, 3.5-4.5 mm, 1-veined, apex acuminate. Utricles yellowish green, shorter or longer than glume, elliptic-lanceolate, trigonous, slightly inflated, 3.5-4 mm, veined, apex gradually narrowed to a short beak, orifice purple, emarginate. Nutlets loosely enveloped, oblong, trigonous, ca. 2 mm; stigmas 3. Fl. and fr. Jul-Aug.
● Thickets, grasslands, rocky slopes; 2900-4100 m. Sichuan, Xizang, Yunnan.