191 



ferred to U. dioica (Rydberg, no. 1790). It is evidently near U. 

 gracilis, from which it differs in the broader thinner leaves, the 

 smaller flower-clusters and the nearly complete absence of bristles. 



CORIOSPERMUM VILLOSUM n. Sp. 



Stem 2-4 dm. high, much branched from near the base, the 

 branches divergent, striate, when young with the leaves and bracts 

 villous with many branched hairs, in age glabrate ; leaves linear, 

 2-4 cm. long, 1-3 mm. wide, cuspidate-mucronate ; spikes rather 

 dense, with more or less imbricated bracts ; lower bracts linear- 

 lanceolate, 5-10 cm. long, the upper ovate-acuminate and cuspi- 

 date, 4-5 mm. long and about 3 mm. wide with broad scarious 

 margin; achene 2-2^ mm. long and 2 mm. wide, acutely margined 

 but scarcely at all winged. 



The following specimens belong to this species: Montana: 

 P. A. Rydberg, no. 2623, 1895, ^''oni Manhattan, in flower. Colo- 

 rado: Isabel Mulford, from Salida, in fruit. S. Watson, no. 993, 

 from Carson Desert, Nevada, 1867, seems also to belong here. 



There are at least three species of Coriosperimim in the United 

 States, viz. : 



C. hyssopifolinm L. with a low branching stem, more or less 

 pubescent when young, very dense spikes with imbricated bracts, 

 which are all broadly ovate, generally over 5 mm. long, and large 

 achenes about 3^-5 mm. long and with broad wing margins It 

 grows around the Great Lakes and northward to the Arctic and 

 westward to Washington. 



C. nitidiun Kit {C. hyssopifolium vticrocarpiim Wats.), with tall 

 slender perfectly glabrous stem, ascending branches, lax spikes, 

 whose bracts are not overlapping each other and are much nar- 

 rower and shorter, 3-4 mm. long and generally narrower than the 

 small, 2 mm. long, broadly winged achenes. I have compared the 

 American form with the European and cannot find any character 

 by which to separate it. It grows from Texas, Kansas, Nebraska 

 to Arizona and Washington (?). 



C. villostun, described above, which resembles C. Jiissopifoliiim 

 in the spikes and the low branching, and C. nitidnvi in the size of 

 bracts and achenes and narrow leaves, but differs from both by the 

 lack of the wing margin and by the longer pubescence. 



