ENGELMANN—DICCIOUS GRASSES. 431 
TWO NEW DICECIOUS GRASSES OF THE UNITED 
STATES. 
By Greorce Encertmann, M.D. 
e grasses, though usually hermaphrodite, show a ten- 
deney to a separation of the sexes, and polygamous flowers 
Only two genera of dicwcious grasses are known to the 
books; of these, Spinifex, Lin., gies . species from the East 
Indies and Australia, bearing on so lants staminate and 
on others complete flowers, is only ; incompletely dicecious ; 
the other genus is Gynerium, H. B. K., with five South 
American species. Some other dicecious species of genera, 
ees hermaphrodite, are noticed; such as Calamagros- 
nd Guadua dioica, Steud. 
