Perennials, (25–) 35–55 (–110) cm tall, robust, loosely caespitose. Rhizome usually thick, to 4.5 mm in diam., horizontal; internodes short; stolons not seen. Stem compressed, two-edged, c. 3–6 mm wide. Cataphylls 1–2, purplish brown with membranous margins, to c. 5 cm long. Sub-basal leaves 1–3. Cauline leaves usually 3–6, (6–) 12–25 (–40) cm long, (3–) 4–9 (–11) mm wide in the middle; sheaths ±loose, with distinct membranous margins; auricles absent; blades pluritubular, imperfectly septate; margins acute, slightly papillose; apex ±subulate. Lower bract leaf-like, c. 2–4 (–7) cm long, shorter than inflorescence. Inflorescence decompound, large, c. 6–15 cm long; primary branches 1–4, ±erect, stiff; secondary branches short, erecto-patent, of many distinct to subcongested heads; heads ±globose, 12–20-flowered (or when congested, to 70-flowered), usually 8 mm in diam. or more. Tepals subequal or outer ones longer, narrowly lanceolate, acuminate, c. 2.8–3.9 mm long, greenish, stramineous-brown to castaneous-brown; margins distinct, scarious. Stamens 6; anthers c. 0.5–0.9 mm long; filaments c. 0.6–0.7 mm long; style difficult to distinguish from the acuminate capsule top, to c. 0.5 mm long; stigmas to 1 mm long. Capsule unilocular, oblong-cylindric, c. 2.8–3.5 mm long, acuminate; capsule segments c. 1 mm wide, ±longer than perianth. Seeds ellipsoid-turbinate, pale brown, c. 0.45–0.55 × c. 0.2 mm, distinctly reticulate, apiculate; appendages absent. 2n = 40, fide S.Snogerup, Bot. Not. 116: 151 (1963).