North American Cyperacece. 269 
11. Cyperus occidentalis. 
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 H 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. 
injiexus of Muhlenberg, but a slight examination shows it to be 
totally distinct. 
12. Cyperus Michaijxianus, ScJiultes. 
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. 1. no. 726. (not of Linn.) ; Michx. ! fl. 1. p. 28; 
Pers. syn. 1. p. 64. 
C. erythrorhizos, Torr. ! fl.l . p. 61 ; Beck! hot. p. 421 ; Gray ! Grain, 
Sf Cyp. part 1. no. 72. 
