2n = 40

Small plants forming mounds or patches 2.5-15 cm high; rhizome slender, far-extending. Leaves setaceous, transverse septa scarcely visible externally. Inflorescence usually a single cluster of 3-5 small flowers. Stamens 6. Capsule to 3mm long, > tepals, glossy black.

Densely tufted, from a long, ascending rhizome, often forming large patches. Stems (2)–5–10–(15) cm. × 0.5–1 mm., much-branched, creeping and rooting at the nodes below. Lvs ∞, both basal and cauline, <, = or occ. > stems, 0.2–0.5–(0.8) mm. wide, narrow-linear, much compressed, almost filiform, septate; sheath ⅓–½ length of lamina, membr., with 2 obtuse auricles. Infl. a single, terminal head of 3–5 fls, or composed of 2–3 branchlets, each terminated by a fascicle of fls; subtending bract > infl. Fls 2–3 mm. long; outer tepals acute or acuminate, straw-coloured at the centre, reddish brown towards the edges, the inner obtuse, greenish brown with broad, clear, membr., margin. Stamens 6, = or slightly > tepals. Capsule up to 3 mm. long, us. much > tepals, oblong-ovoid, mucronulate, pale at first but soon becoming black and shining.