Rhizome slender. Culms tufted, (6-)10-50 cm tall, hairlike, trigonous, soft, smooth or slightly scabrid. Basal sheaths purple-brown, split into reticulate fibers. Leaves longer or shorter than culm, blades hairlike, 0.5-3 mm wide, involute at margins, scabrid. Involucral bracts ± spathelike, shorter than subtending spike, sheathed. Spikes 2 or 3, spaced; terminal spike male, pale brown, linear, ca. 10 × 1 mm, with peduncle 2.8-3.3 cm; lateral spikes female, narrowly cylindric, 7-14 × ca. 2 mm, with a few rather loose flowers, with hairlike peduncle 1.5-2.5 cm. Female glumes yellow-brown, oblong or oblong-ovate, ca. 3 mm (including mucro), costa scabrid, excurrent into a mucro, apex obtuse or truncate. Utricles dark green, equaling glume, elliptic or oblanceolate-elliptic, obtusely trigonous, ca. 3 mm, densely and shortly hirsute, indistinctly veined, base shortly stipitate, apex abruptly contracted into a beak, orifice truncate. Nutlet gray-black at maturity, tightly enveloped, obovate-oblong, obtusely trigonous, ca. 2 mm, base shortly stipitate, apex discoid-annulate; style base thickened; stigmas 3. Fl. and fr. Jul-Sep.