Plants perennial, densely cespitose, 10–40(–53) cm; rhizomes stoloniferous, slender. Culms erect to excurved, leafy based, filiform. Leaves shorter than culm; blades ascending to excurved, filiform, proximally to 1 mm wide, margins involute, apex trigonous, subulate, tapering. Inflorescences: spikelet clusters 1–3, laterals 0–2, turbinate, rarely hemispheric; leafy bracts setaceous, overtopping inflorescence. Spikelets red brown, narrowly lanceoloid, 5–7 mm, apex acute; fertile scales lanceolate, 3.5–5 mm, apex acute, mucronate. Flowers: perianth absent. Fruits 2(–5) per spikelet, (1.7–)2–2.2 mm; body on short, setulose receptacular stipe, brown with pale center, obovoid lenticular, 0.8–1.1 mm, surfaces very finely longitudinally lined, sometimes faintly reticulate cancellate; tubercle triangular subulate, 0.7–0.9 mm, base lunate, edges setulose.