Plants mid-green, deep green or paler green; rhizome short, short-creeping, rarely with nodes elongated; stems sometimes prostrate, submerged or growing in moving sand and rooting at basal nodes. Inflorescence decompound, usually 3–8 × 2–5 cm, with main branches ±erecto-patent, of (1–) 10–35 (–80) usually obconic (less often semiglobose to subglobose) usually (2–) 4–14 (–20)-flowered heads. Tepals equal or subequal, (1.8–) 2.2–3.5 mm long; outer tepals sometimes slightly longer, carinate, ±narrowly bordered, varying in colour from green dorsally with darker lateral bands and apex dark brown or castaneous-coloured, acute or rarely subobtuse and mucronate; inner tepals obtuse to acute, often mucronate, with distinct scarious margins. Anthers (0.4–) 0.5–0.9 mm long, usually ±equalling filaments, rarely slightly longer or shorter; style 0.2–0.3 mm long; stigmas to 1.5 mm long. Capsule trigonous-ovoid, (2.5–) 2.9–4.0 mm long, acute, seldom subobtuse to obtuse, exceeding perianth, usually pale brown to castaneous-brown; rostrum c. 0.3 mm long. 2n = 80, fide N.A.Harriman & D.Redmond, Rhodora 78: 733 (1976); R.L.Taylor & G.A.Mulligan, Fl. Queen Charlotte Is. 2: 43 (1968); M.Zandee, Proc. Kon. Ned. Akad. Wetensch., C, 84: 250 (1981).