Tufted perennial to 60 cm high. Stems 9-60 cm × 2-4 mm, flattened, lacking internal transverse septa. Leaves compressed, longitudinally multitubular, the individual tubes transversely-septate. Inflorescence 5-22 cm long with long branches and large distant flower-clusters. Stamens 3. Capsule c. 5 mm long, > tepals, triquetrous, long-tapered.

Loosely tufted. Stems 9–60 cm. × 2–4 mm., erect, or occ. shortly creeping and rooting at the nodes towards the base, us. compressed, occ. terete. Lvs 8–30 cm. × 2–5 mm., ∞, both basal and cauline, us. < stems, lamina much compressed but hollow, longitudinally multi-tubular, the individual tubes transversely septate, lf-tip us. acute, occ. slightly dilated; sheath broad and loose, with membr. margins and 2 obtuse auricles. Infl. a terminal, much-branched cyme, with globular fascicles of 6–12 fls at the ends of the spreading branchlets; subtending bracts 1–2, lfy, < infl., septate. Fls 3–4 mm. long; tepals acuminate, ± equal or the outer occ. shorter, greenish brown, occ. red, membr. margins very narrow. Stamens 3, c. ½ length of tepals. Capsule 4.5–5 × 1–1.5 mm., us. much > tepals, triquetrous, ovate-lanceolate, gradually narrowed to a mucronate tip, rust- or straw-coloured.