204 



Fig. 500. Bouteloua polystachya (Benth.) Torr. in Pacif. 

 Rail. Rep. 5 : 3G6, t. 10. 1857. {Chondiosium pohjsiaclujum 

 Benth. Bot. Voy. Sulph. 56. 1844.) Six-weeks Gkama. A 

 slender and diffusely spreading, much-branclied annual, 1 to 4 

 dm. liigh, with short, narrow leaves and 3 to 6 linear spikes 

 about 2 cm. long, apiiroximate near the apex of the culm or its 

 branches. Spikelets with glabrous, unequal empty glumes (a), 

 tbe larger second one 1.5 mm. long, and 4-lobed flowering 

 glumes {h), which are awned between the lobes and ciliate on 

 the nerves. River valleys, etc., Utah to Texas and westward 

 to southern California. [Mexico.] July-September. 



