Plants perennial, mat-forming; rhizomes evident, long, 0.3–1 mm thick, soft to firm, cortex often fugaceous, longer internodes 10–25 mm, scales fugaceous, 5–6 mm, membranous, not fibrous. Culms terete, often with some blunt ridges when dry, (5–)10–60 cm × 0.2–1.5 mm, firm, internally spongy. Leaves: distal leaf sheaths persistent, not splitting, proximally red, distally stramineous to green, often callose, thinly papery to thickly membranous, apex often dark red-brown, obtuse to subacute, tooth absent. Spikelets ovoid to lanceoloid, 5–10 × 2–3(–4) mm, apex acute; proximal scale amplexicaulous, entire; subproximal scale with flower; floral scales often spreading in fruit, 10–20, 3–4 per mm of rachilla, brown to often red-brown, midrib regions mostly stramineous to green, broadly ovate, 3–4 × 1.8–2.5 mm, entire, apex acute to obtuse, often some carinate in distal part of spikelet. Flowers: perianth bristles 0–4(–5), light brown to stramineous, stout, usually unequal, rudimentary to equaling achene; stamens 3; anthers dark yellow to stramineous, 1.2–2 mm; styles 2-fid. Achenes not persistent, dark yellow or medium or dark brown, ellipsoid, obovoid, or obpyriform, biconvex, angles obscure, 1.3–1.8 × 1–1.4 mm, apex rounded, neck absent or short, smooth at 30X, or sometimes finely rugulose at 10–20X with 20 or more horizontal ridges in vertical series. Tubercles brown to whitish, pyramidal, much higher than wide to slightly depressed, sometimes spongy and with vertical rows of depressions, 0.4–0.8 × 0.3–0.8 mm.
