242 CYPERACEAE. 
20. Cyperus specidsus Vahl. Michaux’s Cyperus. (Fig. 562.) 
Cyperus speciosus Vahl, Enum. 2: 364. 1806. 
Cyperus Michauxianus Schultes, Mant. 2: 
123. 1824. 
Annual, culms stout or slender, usually 
tufted, 5’-2° tall, reddish toward the 
base. Leaves rough-margined, 114//-2%4/ 
wide, shorter than or equalling the culm, 
the midvein prominent; leaves of the in- 
volucre much exceeding the umbel; um- 
bel compound or nearly simple, 3~7-rayed, 
the primary rays 1/-5 4’ long; involucels 
narrow; spikelets subterete, very nar- 
rowly linear, loosely or densely clustered, 
4//-12/’ long, less than 1/’ thick, 10-30- 
flowered, falling away from the axis at 
maturity; scales dull brown, thin, ap- 
pressed, densely imbricated, ovate, ob- 
tuse, faintly 3-5-nerved on the back; 
rachis-wings broad, clasping the achene, 
persistent; stamens 3; style 3-cleft, slight- 
ly exserted; achene pale, 3-angled, about 
one-half as long as the scale, its super- 
ficial cells nearly quadrate. 
In marshes, Rhode Island to Ohio and Minnesota, south to Florida, Texas and California. 
July—Sept. 
Cyperus specidsus ferruginéscens (Boeckl.) Britton, Mem. Torr. Club, 5: 61. 1894. 
Cyperus ferruginescens Boeckl. Linnaea, 36: 396. 1869-70. 
Scales spreading or slightly recurved, reddish. Missouri to Texas and New Mexico. 
Cyperus specidsus parvus (Boeckl.) Britton, Bull. Torr. Club, 13: 214. 1886. 
Cyperus parvus Boeckl. Linnaea, 36: 397. 1869-70. 
Culm 1/-3' high; umbel very simple, generally of but a single cluster of short spikelets. Mis- 
souri to New Mexico. 
21. Cyperus férox Vahl. Coarse Cyperus. (Fig. 563.) 
Cyperus ferox Vahl, Enum. 2: 357. 1806. 
Annual, closely related to the preced- 
ing species, but with smooth-margined, 
shorter and broader leaves, those of the 
involucre sometimes but little exceeding 
the inflorescence. Umbel simple or some- 
what compound, often compact, the rays 
mostly short; spikelets linear, subterete, 
10-20-flowered, 8’/-12’’ long, about 1/’ 
thick, falling away from the axis at 
maturity; scales ovate-oblong, appressed, 
imbricated, obtuse, rather firm, green and 
7-9-nerved on the back, yellowish on the 
sides; stamens 3; style 3-cleft; rachis 
broadly winged; achene 3-angled, nar- 
rowly obovoid, obtuse. 
In wet soil, Missouri to California and 
widely distributed in tropical America. 
Aug.—Oct. 
