Cyperus imbricatus

C. imbricatus is a coarse, rhizomatous perennial, 70-150 cm tall;rhizomes short, 1-3 cm long, 5-10 mm thick, hardened;roots coarse. Culms erect, trigonous, often subtriquetrous distally, firm, coarsely ribbed, smooth, 3.5 -10 mm wide, sheathing bases 1-3 cm wide. Leaves 3-7;sheaths eligulate, spongy-thickened and purple-black proximately, fading to brown streaked with black distally;ligule absent;blades linear, folded to V shaped proximally, plicate distally, 35-90 cm ? 4-15 (-18) mm, with numerous cross veinlets, scabrous on the margins, abaxial mid-vein, and adaxial lateral veins, long-attenuate to triquetrous apex. Inflorescence a compound umbel-like corymb with ascending rays, 12-30 ?14-30 (-40) cm;involucral bracts 5-10, leaf-like, spreading, ascending to horizontal, the lowermost to 90 cm long;rays 6-12, to 25 cm long;spikes linear-cylindric, 1-6 (-8) cm ? 3-10 (-15) mm, in subradiate groups of (1-) 3-20 at ray tips, with (20-) 30-130 (-160) densely disposed spikelet, compressed, often slightly twisted, 3-6 ? 1-1.4 mm, acute to obtuse at apex, obtuse at base, with 8-22 florets. Stamens 3, the anthers 0.2 - 0.5 mm long, apiculate;styles 3-branched. Achene trigonous, dorsi-ventrally compressed, with the adaxial face plane and the abaxial faces broadly rounded, ellipsoid to ellipsoid-obovoid, 0.5-0.6 ?0.3-0.4 mm, very finely puncticulate to essentially smooth and glossy at maturity, dull whitish to stramineous (Acevedo-Rodr’guez and Strong, 2005).