CYPERACEAE. 



13. Cyperus Bushii Britton. 

 Cyperus. Fig. 733. 



VOL. I. 



Bush's 



Cyperus Bushii Britton, Man. 1044. 1901. 



Perennial by tuber-like corms. Leaves 

 ii"-2" wide, smooth; culms smooth, i-2 

 high, longer than the leaves ; longer involucral 

 bracts much exceeding the umbel ; umbel 

 capitate, or with 1-5 rays ; spikelets loosely 

 capitate, flat, linear, acute, 4"-8" long ; - scales 

 firm, shining, oblong, mucronate, strongly about 

 n-nerved falling away from the persistent axis 

 of the spikelet at maturity; achenes oblong, 

 3-angled, nearly twice as long as thick, apicu- 

 late, two-thirds as long as the scale, some- 

 times persistent after the scales fall. 



Sandy soil, Minnesota to Idaho, Missouri, Texas 

 and Colorado. Resembling C. filiculmis, but the 

 axis of the spikelet is persistent after the scales 

 fall away. July-Sept. 



14. Cyperus pseudovegetus Steud. Marsh 

 Cyperus. Fig. 734. 



Cyperus pseudovegetus Steud. Syn. PI. Cyp. 24. 1855. 

 Cyperus calcaratus Nees ; S. Wats, in A. Gray, Man. Ed. 6, 

 570. 1890. 



Perennial by thickened tuber-like joints of the root- 

 stocks, culm rather stout, i-4 high, often equalled by 

 the leaves. Leaves ii"-2" wide, smooth, nodulose, the 

 midvein prominent; leaves of the involucre 4-6, spread- 

 ing, the longer much exceeding the inflorescence; 

 umbel several-rayed, compound, the primary rays often 

 4' long; spikelets ovate, flat, many-flowered, light green, 

 densely capitate, 2"-$" long; scales keeled, condupli- 

 cate, i-nerved, curved, acute, longer than the linear 

 3-angled slightly stalked achene; stamen i ; style 3-cleft. 



In marshes, New Jersey to Florida, Kentucky, Missouri, 

 Kansas and Texas. Also in the Bahamas. July-Sept. 



15. Cyperus acuminatus Torr. & Hook. Short- 

 pointed Cyperus. Fig. 735. 



Cyperus acuminatus Torr. & Hook. Ann. Lye. N. Y. 3 : 435. 

 1836. 



Annual, culms very slender, tufted, 3'-! 5' tall, longer 

 than or equalling the leaves. Leaves light green, usu- 

 ally less than i" wide, those of the involucre much 

 elongated ; umbel i-4-rayed, simple ; rays short ; spike- 

 lets flat, ovate-oblong, obtuse, 2"-4" long, many- 

 flowered, densely capitate ; scales oblong, pale green, 

 3-nerved, coarsely cellular, conduplicate, with a short 

 sharp more or less recurved tip ; stamen i ; style 3-cleft ; 

 achene sharply 3-angled, gray, oblong, narrowed at each 

 end, about one-half as long as the scale. 



In moist soil, Illinois to South Dakota, Louisiana, Iowa, 

 Kansas, Texas, Oregon and California. July-Oct. 



