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

 Rail. Eep. 5 : 366, t. 10. 1857. (Chondrosium polystachyum 

 Benth. Bot, Toy. Sulph. 56. 1844.) Six-weeks Grama.— A 

 slender and diffusely spreading, much-branched annual. 1 to 4 

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

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

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

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

 glumes (b), 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. 



