Description from Flora of China
Rhizome thick and short, ligneous, stoloniferous. Culms 40-90 cm tall, thick, triquetrous, scabrous on upper part, sheaths at base eventually disintegrating into yellow-brown fibers. Leaves longer than culm, blades 6-8 mm wide, rather stiff, plicate near base and flattened distally, distinctly 2-veined laterally, scabrous on veins and margins. Involucral bracts longer or shorter than culm, lower ones leaflike, upper one setaceous, not sheathed. Spikes 5-8, contiguous at top of culm; terminal spike male, linear, 5-10 cm, subsessile; lateral spikes female, cylindric, 4-12 cm, densely many flowered, subsessile or with short peduncle at lower part. Female glumes pale, narrowly lanceolate, 3-4 mm, membranous, green 1-3-veined, apex aristate, scabrous on margins of awn. Utricles brown, patent, slightly shorter than glume (including length of awn), ovate or broadly ovate, obtusely trigonous, ca. 3 mm, membranous, hispidulous, few veined, base cuneate, apex abruptly contracted into a slender, recurved beak, orifice obliquely truncate, sometimes minutely 2-toothed. Nutlets brownish yellow, loosely enveloped, broadly obovate or subelliptic, trigonous, ca. 1.8 mm; stigmas 3. Fl. and fr. Sep-Dec.
Streamsides, moors, shady and wet places in forests; 300-1600 m. Anhui, Fujian, Guangdong, Guizhou, Hubei, Hunan, Jiangsu, Jiangxi, Yunnan, Zhejiang [Bangladesh, Cambodia, India, Japan, Myanmar, Thailand, Vietnam].