Rhizome shortly creeping, woody. Culms tufted, 30-80 cm tall, slender, trigonous, slightly scabrous, clothed at base with purple bladeless sheaths disintegrating into reticulate fibers. Leaves shorter or longer than culm, blades linear, 2-5 mm wide, flat, densely minutely papillose abaxially, margins scabrous. Involucral bracts leaflike, longer than inflorescence, sheathless. Spikes 3-5; terminal spike gynaecandrous, cylindric, 1-2 cm, densely many flowered, with slender, often pendulous peduncle; lateral spikes female, oblong, 1-1.5 cm, with slender peduncles 1.5-3 cm. Female glumes purple-brown, pale green at middle, ovate-lanceolate, ca. 2 mm, 3-veined, margins broadly white hyaline, apex acuminate. Utricles yellowish green, longer than glume, elliptic or oblanceolate, inflated, horizontally patent at maturity, 2.5-3 mm, finely 5-or 6-veined, base gradually attenuate, apex abruptly contracted into a short beak, orifice 2-toothed. Nutlets obovate, trigonous, ca. 1.5 mm; stigmas 3. Fl. and fr. Jun-Jul.