7. Eleocharis tetraquetra Nees, Contr. Bot. India. 113. 1834; C.B.Clarke, Ill. Cyperaceae: tab. 37, figs. 17-21. 1909; Blake in Proc. Roy. Soc. Queensland 50: pl. 9, figs. 12-15. 1939; Kukkonen in Rech.f., l.c. 64.
Tufted perennial, 20-50 cm. Rhizome rather short, 1-1.5 mm diam., horizontal. Stem 0.5-1 mm diam., trigonous or tetragonous, edges sharp, sides with 1-3 raised veins, smooth, glossy, greyish green. Open sheaths to c. 10 mm; lower closed sheath c. 25 mm, scarious, pale brown or reddish brown for whole length, mouth oblique; upper to 65 mm, pale brown or lowest part often reddish, mouth straight or slightly oblique; blades 0 or minute notch. Spike 5-15 x 2.5-4 mm, from ellipsoid or ovoid to almost globose, with c. 20 to 50 rather closely imbricating glumes; basal glumes 2, sterile, 2-3.5 mm, almost equal, mid-nerve strong, surrounded by brown zone, margins widely scarious; glumes 3-3.5 x c. 1.5 mm, cymbiform, mid-nerve not reaching rounded apex, sides in apical part brown or reddish brown, margins widely scarious. Perianth bristles 4-7, equalling nut (incl. stylopodium), brown, subplumose, with wide, soft, spreading or reflexed barbs; stamens 3, anthers 1.3-1.5 mm; stigmas 3. Nut 1.5-1.8 x 0.9-1.3 mm (excl. stylopodium), ovoid, obtusely trigonous, plano-convex, brown or greenish brown, finely reticulate, glossy; stylopodium 1.1-1.2 x 0.7-0.8 mm, much longer than wide, conical, trigonous, edges convex, white or yellowish, densely hairy, not clearly constricted from nut.
Fl. Per.: August.
Type: Nepal, Wallich 3452 (K).
Wet meadows with flowing water, up to 2100 m; Distribution: Afghanistan, Pakistan, India, Sri Lanka, China, Japan, south to New Guinea and Australia.