22. Cyperus alternifolius Linnaeus, Mantissa Pl. 28. 1767; Syst. Nat. ed. 12, 2: 82. 1767; Jacquin, Ic. Pl. 2(4): pl. 298. 1790.
Tufted perennial, 50-150 cm. Rhizome rather short, horizontal. Stem 4-7 mm diam., obtusely trigonous, smooth to finely scabrous. Leaf blades reduced; sheaths to more than 30 cm, coriaceous, upper yellowish or grey, lower reddish brown or black brown, mouth margin oblique; ligule 0; blades 0. Inflorescence a compound anthelodium, 3-13 cm; bracts 18-22, to more than 30 cm, to 15 mm wide, foliose or upper filiform, green or greyish-green, acute, flat, margins narrowly recurved, margins and main nerves smooth or variously scabrous; primary branches up to c. 10 cm, spreading, smooth or slightly scabrous, almost terete, tubular prophyll green or brownish, basal part spongy; secondary anthelodia 10-30 mm, with bracts to c. 5 mm; tertiary anthelodia occasional; cluster of spikes 5-10 mm, globose, with 5-25 spirally arranged spikes ; spikes 3.5-9 x c. 2 mm, with 7-30 closely imbricating glumes, glume-like bract scarious, c. 1.2 mm, glume-like prophyll bi-nerved, rounded, c. 1.2 mm; rachis four-angled, c. 0.5 mm wide, internodes c. 0.5 mm, not markedly winged; glumes c. 1.5 mm, cymbiform, lanceolate to elliptic, mid-nerve pronounced, barely reaching apex, margins scarious, colourless or pale brown. Stamens 3. Nut c. 0.6-1 x 0.3-0.5 mm, ellipsoid or obovoid, trigonous, light brown or dark greyish brown, finely papillose.
Lectotype: Herb. Linn. 70.40 (LINN) ; selected by Baijnath, Kew Bull. 30: 521. 1975.
Distribution: Area of subsp. flabelliformis covers the area of the species; subsp. alternifolius originates from Madagascar and the Mascarenes, where it was not collected recently, but cultivated in botanical gardens.