Cyperus vaginatus
R.Br.Tussock-forming perennial, occasionally proliferating, with short, thick rhizome. Culms terete, rigid, smooth, to 100 cm high, to c. 3 mm diam. Leaves reduced to sheaths except in juvenile plants. Inflorescence simple or compound, with 4–12 primary branches to 6 cm long but often less, or sometimes head-like; digitate clusters to 2 cm diam.; involucral bracts mostly 5–8 exceeding inflorescence, with apex acute but not pungent, rather rigid. Spikelets flattened, 4–15 per cluster, 5–18 mm long, 2–2.8 mm wide in side view, 8–40-flowered; rachilla not winged, persistent; glumes short-mucronate, with 3-nerved keel, red-brown to straw-coloured, 2–2.5 mm long; stamens 3. Nut trigonous, obovoid to ellipsoid, grey-brown, scarcely one-half as long as glume, 0.6–0.8 mm long, c. 0.5 mm diam. Flowers spring–summer.
All mainland states. Apparently collected only a few times in Victoria, from Lake Lalbert near Swan Hill, Dimboola and the northern Grampians. Not collected in Victoria since 1913 and possibly now extinct at these localities.
Wilson, K.L. (1994). Cyperaceae. In: Walsh, N.G.; Entwisle, T.J., Flora of Victoria Vol. 2, Ferns and Allied Plants, Conifers and Monocotyledons, pp. 238–356. Inkata Press, Melbourne.