213 



Fig. 207. BOUTELOUA BURKll Scribn. in S. Wats. Proc. Am. Acad. 18: 

 179. 1883. BURK'S GRAMA.— A slender, tufted perennial 15-20 cm. (6'-8') 

 high, with short, spreading leaves and slender, horizontal spikes 1-2 cm. (i'-l') 

 long. Sheaths shorter than the internodes; leaf-blades mostly crowded at the 

 base, 1-3 cm. (i'-W) long, 1 mm. {h") wide. Spikelets, about 4 mm. long; 

 empty glumes (a) subequal, 1-nerved, smooth; flowering glume (5) exclusive 

 of the three equal awns less than 2 mm. (1") long, pilose on back and margins; 

 pedicel of rudiment (d) 1 mm. H") long, bearing three equal scabrous awns 

 5 mm. (2i") long.— Sandy plains and dry mesas, western Texas. (Northern 

 Mexico). April to July. 



Related to Bouteloua trifida, which differs from this species in its larger size, 

 narrower, unequal empty glumes, and smooth flowering glume. 



