North American Cyperacece. 259 



11. CyPERUS OCCiDENTALlS. 



Culms densely cespitose, thick and very short; leaves flat ; 

 rays of the umbel short, crowded ; spikelets cloiscly aggregated 

 into ovate heads ; the lowest ones compound, 8 — 10-flowered ; 

 scales ovate, rather acute, membranaceous ; style 3-cleft at the 

 summit ; nut ovate, compressed-triangular. 



Annual ? Culms acutely triangular, numerous, forming dense tufts about 

 two inches high. Leaves broad for the size of the plant. Umbel large, 

 of 3 — 4 short rays. Involucre about 3-leaved, much longer than the um- 

 bel ; the leaflets li line broad. Spikelets very numerous, 3 lines long, 

 those on the lower part of the rays more or less compound. Scales rather 

 loosely imbricated, not scarious on the margin, with a broad deep-green 

 keel and ferruginous sides. Interior scales very conspicuous. Stamens 

 3. Style long, slightly cleft. Nut smooth, short, ovate. 



Hab. On the North-west coast of America, near the mouth 

 of the Oregon river! 



Obs. This humble species, for which I am indebted to my 

 excellent friend, Dr. Hooker, resembles, at first sight, the C. 

 injlexus of Muhlenberg, but a slight examination shows it to be 

 totally distinct. 



12. Cyperus Michauxianus, Schultes. 



Culm acutely triangular ; umbel compound, the rays short; 

 involucels 1 — 2-leaved, setaceous, or wanting ; spikelets some- 

 what terete when mature, 6-8-flowered, the lower ones com- 

 pound ; rachis very broad, easily separating at the joints ; scales 

 ovate, rather obtuse ; interior scales herbaceous, obovate, folded 

 round the ovate, triquetrous nut. 



C. Michauxianus, Schult. mant. 2. p. 123. 



C. strigosus. Lam. ill. I. no. 726. (notof Zznn.) ; Michx. .' fl. 1. p. 28; 

 Pers. syn. 1. p. 64. 



C. erythrorhizos, Tbrr..' ^.1. p. 61; Beck! hot. -p. ^21; Gray! Gram. 

 Sf Cyp. part 1. no. 72. 



