Rhizome short. Culms sublateral, 15-40 cm tall, slender, compressed trigonous, smooth, clothed with pale brown (sometimes purple-red) bladeless sheaths at base. Leaves shorter or longer than culm, blades linear, 4-8 mm wide, flat, apex acuminate. Involucral bracts shortly bladed, sheathing 2-4 cm. Spikes 3 or 4; terminal spike male, lanceolate-oblong, 4-8 mm, very close to next female spike; remaining spikes female, oblong, 6-10 mm, 2- or 3-flowered; peduncles slender, erect, long exserted beyond involucral bract blade. Female glumes pale, occasionally tinged with brown, ovate-oblong, 3.5-4.5 mm, green obscurely 3-veined costa ending at muticous apex. Utricles brown-green, ca. 2 × as long as glume, fusiform, trigonous, 5.5-6.5 mm, herbaceous, glabrous, faintly many veined, base cuneate, apex gradually narrowed to a long upright beak, orifice hyaline, 2-toothed. Nutlets pale brown, tightly enveloped in lower part of utricle, obovate or elliptic, trigonous, ca. 3 mm; style base not thickened; stigmas 3. Fl. and fr. Apr-Jun.

Forests; below 500-1100 m. Fujian, Guangxi, Hunan, Taiwan, Zhejiang [Japan].