Cyperus radiatus Vahl, Enum. Pl. 2: 369. 1805; Kükenthal, in Engler, Pflanzenr. IV.20, 101: fig. 9, G-J. 1935.

Perennial, 30-60 cm. Rhizome short, ascending or horizontal, with tillers. Stem 2-3 mm diam., trigonous, smooth, lower edges obtuse. Leaves shorter than or equalling stem; sheaths to 20 cm, soft, brown or dark brown, often reddish, mouth margin slightly concave; blades to c. 40 cm long, to 5.5 mm wide, flat or folded, keeled, margins narrowly recurved, margins and keel towards apex scabrous, apex trigonous, acute, scabrous. Inflorescence 5-15 cm, a conical or rounded anthelodium; 4 or 5 lowermost bracts leaf-like, to more than 40 cm; primary branches commonly 5-8, to 80 mm, tubular prophyll c. 10 mm, bi-nerved; secondary anthelodia to c. 40 mm, of 5-8 spreading clusters of spikes; sometimes small tertiary anthelodia by 2-3 clusters of spikes, c. 7 mm; cluster of spikes 10-35 x 3-8 mm, with c. 20 to over 100 spikes closely imbricating, spirally, some at cluster base often digitately arranged; cluster rachis reddish brown, angular, narrowly winged; spikes not reflexed, 4-8 x c. 1.5 mm, glume-like bract, c. 0.8 mm, bi-nerved glume-like prophyll, c. 0.6 mm, rachis c. 0.3 mm wide, flat, quadrangular, internodes c. 0.25 mm; glumes c. 1.5 mm, cymbiform, slightly keeled, mucronate, sides obscurely nerved, reddish brown, margins widely scarious, sligthly inrolled. Nut 0.6 x 0.3 mm, ellipsoid, obtusely trigonous, yellowish brown, very finely reticulate, almost smooth.

Fl. Per.: June.

Type: India, Tamil Nadu: "E. Tranquebaria misit Cel. König" (LD!). To be expected in Pakistan as recorded from India, Rajahstan: "Mt. Abu, in der indischen Wüste”, Meebold n. 4849 (Kükenthal, l.c., 1935: 71, as var. multiflorus Kük.), and from Afghanistan: Kandahar, Arghandab, Kitamura 37 (Koyama in Acta Phytotax. Geobot. 17:47, 1957).

Alluvial marshes; Distribution: Pantropical.

The description is primarily based on five specimens from India.