Description from Flora of China
Rhizome obliquely ascending, thick. Culms lateral, 30-45 cm tall, slender, obtusely trigonous, smooth, clothed at base with pale brown or dark brown bladeless sheaths. Leaves longer than culm, blades light green, broadly linear, 7-18 mm wide, leathery, flat, revolute, upper margins scabrous, apex acuminate. Involucral bracts shortly bladed, shorter than subtending spike, scabrous margined, long sheathing. Spikes 3 or 4; terminal spike male, linear-cylindric, 1.5-4 cm, loosely many flowered, long pedunculate; lateral spikes 2 or 3, mostly female, sometimes bearing a few male flowers at apex, cylindric, 3-6 mm, loosely flowered, with erect peduncles 4.5-5 mm. Female glumes yellow-white, ovate-lanceolate, 4-5 mm, green 3-veined costa ending in an awn at acuminate apex. Utricles pale brown or brown-olivaceous, longer than glume, horizontally patent at maturity, ovate-orbicular, inflated trigonous, 4.5-6 mm, papery, slightly scabrous, many veined, apex abruptly contracted into a cylindric long beak, orifice deeply 2-lobed. Nutlets dark black, loosely enveloped, obovate, ca. 2 mm, trigonous with angles constricted at middle, faces concave at base, base curved stipitate; style base thickened, oblique, persistent; stigmas 3. Fl. and fr. May-Jul.
● Rock crevices, moist places in forests; 1100-2000 m. Gansu, Hubei, Shaanxi, Sichuan.