C. iria L. var. rectangularis Kük., in Engler, Pflanzenr. IV. 20, 101: 152. 1935; Cyperus iria L. var. paniciformis C.B. Clarke in Hook.f., Fl. Brit. Ind. 6: 607. 1893; Kern in Reinwardtia 1: 465, fig. 1. 1952; A. Ahuja, Illustrations of Indian plants, Cyperus I, Bull. Nat. Bot. Gardens 85: pl. 6 (as C. iria L.) 1963; Uniyal & al., Cyperaceae of Uttar Pradesh: 16. 1997.

Annual, 12-40 cm. Roots numerous, glabrous. Stem 1-2.5 mm diam., sharply trigonous, smooth. Leaves shorter than to equalling stem length, rather rigid; sheaths 25-45 mm, yellowish or grey, wide, mouth margin deeply concave; blades up to 15 cm, 3 mm wide, flat or slightly keeled, with brown dots and stripes, margins smooth, apex acute, scabrous. Inflorescence a simple or compound anthelodium, 4-17 cm, primary branches 6-10, up to 13 cm, secondary anthelodium to 35 mm, tubular prophyll loosely sheathing, to 15 mm; lowest 4-6 bracts foliose, to more than 20 cm. Cluster of 6-16 spikes in loose spirals; spikes 4.3-10.8 x 2-2.5 mm, spreading at almost right angles, glume-like bract 1-1.5 mm, glume-like prophyll c. 1 mm, blunt, bi-nerved; rachis 4-angled, compressed, reddish brown, internodes c. 1.5 mm; glumes 1.5-2 mm, cymbiform, keel scabrous or smooth, sides prominently nerved, margins widely leathery, hard, brown. Stamens 2, anthers c. 1 mm; stigmas 3. Nut c. 1.5 x 0.8 mm, plano-convex, sharply triangular, from brown to dark-brown, finely reticulate, with papilla in each areole.

Fl. & Fr.: September.

Holotype: India, Punjab, Drummond 24733 (BO) isotype (K).

Rice fields, wet places to 1500 m; Distribution: Afghanistan, Pakistan, NW and C India (Bhandari 1990), ?Australia (Kükenthal in Engler, Pflanzenr. 4. 20: 101. 1935).