Rhizome woody, oblique. Culms tufted, 20-65 cm tall, slender, obtusely trigonous, clothed at base with red-brown to dark brown sheaths eventually disintegrating into parallel fibers. Leaves shorter than culm, involute, slightly rigid, gray-green, margins scabrous, apex acuminate. Involucral bracts setaceous, shorter than inflorescence, shortly sheathing. Spikes 4-6; upper 3 or 4 male, approximate, linear-cylindric, 0.8-2 cm, sessile; remaining spikes female, remote, oblong-cylindric, 1-3 cm, with slender, slightly scabrous peduncles. Female glumes castaneous, pale at middle, broadly ovate or ovate-oblong, 4-4.5 mm, margins broadly white hyaline. Utricles yellow-green, brown above, longer than glume, suberect, oblong-elliptic, compressed trigonous, 5-7 mm, membranous, many veined, base gradually narrowed to a stipe, margins hispidulous, apex abruptly contracted into a conic long beak, orifice white hyaline. Nutlets stramineous, oblong-obovate, trigonous, ca. 2.5 mm, base with stipe ca. 0.7 mm; style erect, scabrous; stigmas 3. Fl. and fr. Jul.