GENERA OF GRASSES OF THE UNITED STATES. 
177 
this sometimes bearing a rudimentary lemma ; glumes narrow, acumi- 
nate, 1-nerved, about equal, shorter than the floret; lemma strongly 
compressed, pubescent on the keel, firm in texture, 3-nerved, the 
lateral nerves close to the margins. 
97760°— 19— Bull. 772 12 
