Description from Flora of China
Rhizome stout, obliquely ascending. Culms densely tufted, 10-35 cm tall, ca. 1.5 mm thick, slender, compressed triquetrous, scabrous on upper part. Leaves shorter than culm when young, eventually elongating, equaling or longer than culm, blades 1-2.5 mm wide, flat, soft, margins slightly scabrous, base purple-brown and persistent sheathed, sheaths eventually disintegrating into fibers. Involucral bracts spathelike, sheath green and brownish lined, brownish abaxially, white and membranous at sheath mouth and adaxially, lower 1 or 2 involucral bract blades setaceous, remaining blades mucro-shaped. Spikes 3-6, remote; terminal spike male, linear-cylindric, 5-15 mm, 1.5-2 mm thick, shorter than or equaling adjacent female spike; lateral spikes 2-5, female, oblong or oblong-cylindric, 1-1.7 cm, 2.5-3 mm thick, loosely or subdensely 5-10-flowered, or loosely 2- or 3-flowered; peduncles usually not exserted from involucral bract sheath, lowermost one slightly exserted; rachis slightly or distinctly flexuose. Female glumes purple-brown laterally, green at middle, lanceolate, obovate-lanceolate, obovate, or obovate-oblong, 5-6 mm, papery, 3-veined, margins broadly white hyaline, apex acute, mucronate. Utricles greenish, shorter than glume, obovate-oblong, obtusely trigonous, ca. 3 mm, papery, densely pubescent, 2-veined laterally and convexly several veined, base abruptly contracted into a long stipe, apex rounded, shortly beaked, orifice truncate. Nutlets obovate-elliptic, trigonous, 2.5-2.8 mm, base shortly stipitate, apex with recurved and short beak; style base slightly thickened; stigmas 3. Fl. and fr. Apr-Jul.
Forests, grasslands at forest margins, dry grasslands on sunny slopes, mountain slopes, thickets, watersides, field margins, on rocks; 100-2300 m. Anhui, Gansu, Guizhou, Hebei, Heilongjiang, Henan, Hubei, Jiangsu, Jiangxi, Jilin, Liaoning, Nei Mongol, Ningxia, Shaanxi, Shandong, Shanxi, Sichuan, Yunnan, Zhejiang [Japan, Korea, Mongolia, Russia (Far East, E Siberia)].