Scirpus geniculatus L., Sp. Pl. 1: 48. 1753; E. caribaea (Rottb.) Blake in Rhodora 20: 24. 1918; Scirpus caribaeus Rottb., Descr. Pl. Rar.: 24. 1772; E. capitata R.Br., Prodr. 1: 225. 1810; C.B.Clarke in Hook.f., l.c. 627, non Scirpus capitatus L.; E. caduca (Del.) Schultes, Mantissa 2: 88. 1824; Scirpus caducus Del., Descr. Egypte, Hist. nat. 9 (1813 n.v.); K.M. Matthew, Fl. Tamilnadu Carnatic 4: pl. 654. 1988.

Tufted annual, 12-25 cm. Roots white, fibrous. Stem 0.5-1 mm diam., green, with 5-6 obtuse angles separated by deep grooves. Open sheaths c. 5 mm, wide, scarious; lower closed sheath to 15 mm, reddish brown or green, mouth oblique, upper to 50 mm, green or basal parts reddish, with 5 nerves, mouth oblique, margin narrowly scarious; blades 0 or minute tip. Spike 3-6 x 3-4 mm, ovoid or globular, with 50 or more very closely imbricating glumes; basal glume fertile, not distinct from other glumes or its mid-nerve more pronounced and stronger; glumes 1.7-2.2 mm, not in protruding spiral rows, cymbiform, rounded, mid-nerve not very distinct, not reaching apex, sides grey brown, margins narrowly scarious. Perianth bristles 6-8, as long as or longer than nut, brown; stamens 2-3, anthers 0.5-0.7 mm; stigmas 2. Nut 0.8-1 x 0.6-0.8 mm (excl. stylopodium), obovoid, bi-convex, apex rounded, basal part gradually tapering, obscurely reticulate, glossy, finally black; stylopodium 0.1-0.2 x 0.3-0.4 mm, much wider than long, white, clearly constricted from nut.

Fl. Per.: April -June.

Type: In Herb. Hortus Cliffortianus (BM) lectotype, sel. J. Dandy, in Svenson Rhodora 41: 50, 1939).

Rice fields, marshlands, wet meadows; Distribution: Pantropical extending into subtropics; Europe (Italy), Africa, Madagascar, Egypt, from Iraq to Pakistan, India, China, Taiwan, Malaysia, Australia, N and S America.