2n = 30

Rhizome pale brown, often very slender, 1–3 mm. diam. Culms (1)–3–12 cm. long, setaceous, us. much < 0.5 mm. diam., rather densely tufted; sheaths very thin and membr., transparent, red-veined, the upper sheath colourless and rather inflated below the oblique orifice. Spikelet 2.5–3 × c. 1mm., few-fld, ovate, acute. Glumes 1.5–2 mm. long, ovate, obtuse. Hypog. bristles us. 0, occ. 2–3. Stamens 3. Style 3-fld. Nut c. 1 × 0.5 mm., narrowly obovoid, obscurely trigonous, almost white, each face with 3–4 thick, vertical ribs joined by fine transverse bars; the persistent style very small, much constricted at base.