Perennial, forming small tufts, sterile stems to 140 cm. Rhizome short, emitting white stolons which end in a spherical, edible tuber. Stem 3-5 mm diam., terete, with conspicuous septae 2-5 cm apart, often with less pronounced septa between. Sheaths absent (in specimens studied). Spike 20-50 x 7-10 mm; two basal glumes green, lower almost completely clasping, upper opposite, smaller; glumes 6.5-8 mm, finally yellowish grey, cymbiform, with clear mid-nerve, other nerves obscure, margin scarious, c.0.5 mm wide, apex rounded. Perianth bristles 6-8, rigid, yellowish, c. equalling nut; stamens 3; stigmas 2 or 3. Nut 2-2.3 x 1.6-1.8 mm (without stylopodium), thickly bi-convex, spherical or obovoid, brown or yellow-brown, shiny, surface finely reticulate, with c. 0.5 mm stipe, apical annulus bordering style base; stylopodium c. 1 x 0.8 mm. conical, flat or shallowly trigonous, brown or dark brown, often with remains of whole style attached.