Rhizome obliquely ascending. Culms tufted, 30-60 cm tall, medium thick, triquetrous, smooth, clothed with bladeless brown-red sheaths at base. Leaves shorter than culm, blades 3-6 mm wide, flat, distinctly 2-veined laterally, lower sheaths usually brown-red. Involucral bracts leaflike, shorter than culm, long sheathed. Spikes 6 or 7; terminal spike male, linear, ca. 4 cm; lateral spikes female, narrowly cylindric, 2.5-7 cm, densely many flowered, uppermost 2 contiguous at top of culm, subsessile, lower ones slightly remote, with very short peduncle. Female glumes pale, lanceolate, ca. 2 mm, membranous, greenish 1-veined, apex acuminate, with a short awn. Utricles brown-green, obliquely patent, longer than glume, elliptic, obtusely trigonous, 2-2.8 mm, membranous, inconspicuously 5-veined, hispidulous on veins, base cuneate, apex abruptly contracted into a ± long beak, orifice obliquely truncate or later emarginate. Nutlets yellowish, rather tightly enveloped, subelliptic, trigonous, ca. 1 mm, verrucose; style base thickened; stigmas 3, rather short. Fl. and fr. May-Jun.