Plants densely tufted, mat-forming by means of rooting culm tips. Culms 1.5–3 times as wide as thick, 20–100 cm × 0.35–2 mm, firm to hard, wiry, with to 8 subacute ribs, rarely nearly smooth; some culms arching or decumbent and rooting at tips. Leaves: distal leaf sheaths not splitting abaxially, proximally dark red to brown, apex usually reddish. Spikelets ovoid, 5–17 × 2.5–5 mm, apex acute; spikelets on stolons rudimentary, non-flowering, proliferous when rooting; proximal scale empty, amplexicaulous, ovate, 2–4 mm; subproximal scale with flower; floral scales 20–40, 2–3 per mm of rachilla, stramineous to medium brown, midrib region paler, ovate, 3.5–6 × 2–3 mm, membranous to cartilaginous, apex entire, rounded to subacute. Flowers: perianth bristles brown, equaling achene or tubercle, densely spinulose; anthers brown, 2–2.4 mm. Achenes often very variable within one plant, ovoid to obovoid or obpyriform, 1.5–2.5 × 1–1.2 mm, beak to 1 × 0.6 mm. Tubercles when present pale to dark brown, pyramidal, to 0.5 × 0.3 mm.
