Perennials, (20–) 25–110 cm tall, rhizomatous, forming large loose stands. Rhizome creeping, stout, sparsely branched, with internodes 0.5–1.5 mm long. Stem erect; cataphylls 2–3, with uppermost to 20 cm long. Cauline leaves 2–4 (–6), 5–50 cm long, 0.7–2 mm wide, unitubular, perfectly septate (septa visible externally, ±distinct); auricles ±firm, scarious, small, c. 1.0–1.5 mm long, obtuse. Inflorescence lax or ±condensed, with (8–) 30–80 (–250) heads, each of (3–) 5–10 (–20) flowers. Lower bract leaf-like, shorter than inflorescence (rarely equal or longer). Tepals unequal; inner tepals (1.8–) 2–2.8 mm long; outer tepals shorter, (1.5–) 1.7–2.3 (–2.5) mm long, ±narrowly ovate, apiculate to cuspidate, usually slightly recurved at apex, castaneous-coloured at least distally, greenish or pale brown at base, sometimes greenish when young, with narrow scarious margin. Stamens 6; anthers (0.6–) 0.7–1 mm long, longer than 0.3–0.55 (–0.7) mm filaments; style 0.5–1 mm long; stigmas 1–1.5 mm long. Capsule (2.3–) 2.5–3.5 (–4) mm long, exceeding perianth, unilocular, trigono-ovoid to narrowly pyramidal, gradually narrowed in a 0.5–1 mm rostrum, brownish, shiny. Seeds ±ovoid to ellipsoid, 0.4–0.5 (–0.6) × c. 0.2–0.3 mm, c. 25-striate, reticulate; appendages absent.