Rushlike. Culms 50–100–(200) cm. × 1–1.5–(2) mm., , densely packed, wiry, erect, terete. Lvs all reduced to closely appressed reddish sheaths, with a subulate, almost filiform lamina 0.5–2 cm. long. Infl. a simple or rarely branched spike, 3–9 cm. long. Spikelets c. 1 cm. long, not fascicled, 2-fld, only the upper fl. fertile; bracts subtending spikelets membr., grey-brown, nerved, ± = spikelets. Glumes 4–6, narrow- or oblong-lanceolate, acute or acuminate, with dark brown centre and pale membr. margins. Hypog. Scales 6, c. 1 mm. long, white and triangular when mature, fused at the base into a cup. Nut c. 4 × 1.5 mm., oblong, trigonous, green with white thickened obtuse angles; persistent style-base small, creamy brown, pubescent, occ. minutely apiculate.