GENERA OF GRASSES OF THE UNITED STATES. 149 
69. SPoROBOLUS R. Br, 
Spikelets 1-flowered, the rachilla disarticulating above the glumes; 
glumes awnless, usually unequal, the second often as long as the spike- 
let; lemma membranaceous, 1-nerved, 
awnless; palea usually prominent and 
as long as the lemma or longer; seed 
free from the pericarp. 
Annual or perennial grasses, with 
small spikelets in open or contracted 
= 
RES 
eS 
BB ple 
a. 
pO STB EE oN 
Pic. 84,—Smut-grass, Sporobolus bertcroanus. Plant, ~*~ 4; spikelet and floret, * 5. 
