Herbs, perennial, cespitose, bases cormose; rhizomes knotted, beaded. Culms trigonous, (3–)10–50 cm × 0.4–1.2 mm, glabrous. Leaves flat, 5–40 cm × 1–3.5 mm. Inflorescences: spikes rather densely ovoid to globose, 1.2–3.5 cm; rays 0 or 1–4, 1–6 cm; rachis 1–3.5 mm; bracts 2–4, horizontal to reflexed, flat, 6–25 cm; rachilla ± deciduous, wingless. Spikelets 15–60, compressed, oblong-lanceoloid, (3–)6–22 × 2.5–4 mm; floral scales deciduous, 5–22, off-white to light reddish brown, laterally 3–5-ribbed, ovate-elliptic, 2.5–4 × 2–2.6 mm, margins loosely spreading or clasping achene, apex entire to mucronate, mucro 0.05–0.2 mm. Flowers: anthers 0.3–0.6 mm; styles 1 mm; stigmas 1–1.5 mm. Achenes dark brown or black, sessile, oblong-ellipsoid to ellipsoid, 1.7–2.2 × 0.8–1.2 mm, apex obtuse, apiculate, surfaces puncticulate. 2n = 166.
