19. Cyperus compressus Linnaeus, Sp. Pl. 1: 46. 1753; Boiss., Fl. Or. 5: 372. 1882; C. B. Clarke, l.c. 605; R. R. Stewart, l.c. 86; Kukkonen in Rech.f., l.c. 110.
Chlorocyperus compressus Palla, in K. Rech., Denkschr. Math.-Naturw. Kl. Akad. Wiss. 84: 451. 1908; Britton & Brown, Ill. Fl. north. U.S., ed. 2, 1: fig. 729. 1913; K.M. Matthew, Fl. Tamilnadu Carnatic 4: pl. 632. 1988.
Annual, 3-27 cm, forming small tufts. Stem 0.5-2 mm diam., sharply trigonous, smooth. Leaves from half to slightly shorter than stem; sheaths up to 50 mm, lowest blade-less, greenish grey, yellowish or often slightly brownish, soft, mouth margin wide, slightly concave; blades up to 16 cm, 2.5 mm wide, flat or folded, keeled, margins slightly revolute, smooth, apex acute, scabrous. Inflorescence a simple anthelodium, to 10 cm, or single cluster of spikes, primary branches 0-4, up to 85 mm, tubular prophyll up to 8 mm; lowest 3-5 bracts foliose, 3-20 cm; cluster of spikes 10-20 cm, with 3-9 digitately arranged spikes; spikes 8-20 x c. 4 mm, compressed, ovoid or elongate ellipsoid, green to yellowish brown, glume-like bract c. 2.7 mm, acute, glume-like prophyll c. 1.7 mm, blunt; rachis compressed, c. 0.7 mm wide, narrowly winged, grey, brown-dotted, internodes 0.5-1 mm; glumes c. 4 mm, arista 0.5-0.7 mm, sides with several prominent nerves, grey, brown-dotted, margins scarious. Stamens 2-3; stigmas 3. Nut 1.5-1.7 x c. 1.2 mm, obovoid, plano-convex, rather sharply trigonous, yellowish brown, smooth.
Type: "In Americae septentrionalis pratis arenosis.".
Weed in grasslands, road sides, waste places and fallow rice fields; "prolific monsoon species" (Bhandari, Fl. Ind. Desert: 332. 1990); Distribution: Pantropical, except Australia; extending from India to Afghanistan; in Himalayas up to 1200 m.