3I g NATURAL HISTORY BULLETIN. 



CYPERACE^E. 



Cyperus L. Sp. PL, 44 (i753)- 



A very large genus of annual and perennial sedges, widely 

 distributed in tropical and temperate regions. The species 

 are of little economic value, furnishing a small percentage of 

 inferior pasturage along the margins of ponds and streams 

 and on marshy land. 



Species about 650. 



Illustrated Flora, 32; Gray's Manual, 6th ed., 25; MacMillan, Metas. Minn. 

 Vallev, 9; Arthur, Flora of Iowa, 8; Tracy, Flora of Missouri, 16; 

 Brendel, Flora Peoriana, 9; Webber, Flora of Nebraska, and Rep. i-iv, 

 11; Williams, Grasses and Forage Plants of the Dakotas, 4; Fink 

 Flora of Fayette, Iowa, 6. 



i. C. diandrus Torr. Cat. N. Y., 90 (1819). 



Illus. Flora, 1. 236, fig. 544; Gray's Man , 6th ed., 569; Hitchcock, PI. Ames 

 523; MacMillan, Metas. Minn. Val., 93; Tracy, Fl. Missouri, 90; Bren- 

 del, Fl. Peoriana, 61; Wheeler, Fl. Milwaukee Co., Wis., 186; Rydberg, 

 Fl. Sand Hils, Neb., 184; Fink, Iowa Acad. Sci., iv, 105. 



Low ground, sandy shores of streams and lakes. Probably 

 throughout the state but not common. Quite variable, closely 

 approaching the next species in some forms. 



Muscatine and Ames, Hitchcock; Decorah, 1881, Holway ; 

 Fremont County, 1894, Rink; Clinton County, 1896, Pammel; 

 Moscow, 1894, Barnes & Miller; Grinnell, Aug., i886,Jo/Mson. 



2. C. rivularis Kunth. Enum., 11, 6 (1837). 



C. diandrus var. castatieus Torr., Ann. Lye. N. Y., 111,252 (1836), not Willd. 

 (1798). 

 Illus. Flora, 1, 236, Fig. 545; Gray's Man., 6th ed., 569; Arthur, Fl. Iowa, 33; 

 Hitchcock. PI. Ames, 523; MacMillan, Metas. Minn. Val., 93; Webber, 

 App. Fl. Neb., 24; Fink, Iowa Acad. Sci. iv, 105. 



Same situations as the last. Varies from a couple of inches 

 to over a foot in height. A beautiful species, the bright, 

 chestnut-colored scales very conspicuous. 



Ames, 1875, Arthur; Lawler, 1890, Rolfs; Emmet and 

 Dickinson counties, various collections, Cratty; Woodbine, 

 1874, Burgess; Scott and Muscatine counties, frequent, 

 Barnes & Miller ; Charles City, Aug., 1875, Arthur. 



