23 



Fig. 319. Andropogon hallii Hack. Sitzungsber. Ak. Wiss. 

 Wien, 89 : 127. 1884. Colorado Sand-grass. — A stout, glabrous 

 perennial 4 to 10 dm. or more bigb, with rather long (the lower 10 

 to 20 cm.), flat leaves and stout racemes which are in pairs or in 

 threes and 5 to 8 cm. long. Sessile spikelet (a) about 8 mm. long, 

 with the first glume (b) ciliate along the keels and pilose-hairy 

 toward the apex. Awn shorter than the spikelet or wanting. — 

 Dry sandy soil, North Dakota, Montana, southward to Kansas, 

 Texas, and New Mexico. [Mexico.] July-September. 



