Description from Flora of China
Rhizome short, stout. Culms 20-55 cm tall, trigonous, rigid, smooth, clothed at base with dark brown sheaths disintegrating into parallel fibers. Leaves surpassing culm, blades broadly linear, 5-10 mm wide, flattish, apex acuminate. Involucral bracts leaflike but much shorter than inflorescence, sheathing. Spikes 4 or 5, distant; terminal spike male, linear, 2.5-4 cm, with peduncle ca. 4 cm; lateral spikes mostly female, sometimes with several male flowers at apex, narrowly cylindric, 3.7-7 × 0.9-1 cm, densely flowered, lowest peduncle 5-7.5 cm, smooth. Female glumes pale or yellow-brown, linear-lanceolate, green 3-veined costa ending at apex. Utricles brownish green, longer than or nearly equaling glume, obliquely patent, ovate or obovate (excluding beak), 6-7 mm (including beak), herbaceous, pubescent above, many veined, contracted at both ends, apex abruptly contracted into a linear beak ca. 3 mm, orifice 2-lobed with sharp teeth. Nutlets black-purple, tightly enveloped, ovate, ca. 2 mm, trigonous with angles constricted at middle, faces concave at base, base curved stipitate, apex abruptly contracted into a cylindric beak ca. 1 mm, beak slightly annulate at orifice, rarely beak absent; style base en-larged; stigmas 3. Fr. Apr-May.
● Forested slopes, streamsides; 500-700 m. Anhui, Fujian, Hubei, Hunan, Jiangxi, Shaanxi, Taiwan, Zhejiang.