209 



Fig. 203. BOUTELOUA ROTHKOCKIi Vasey, U. S. Dept. Agr. Spec. Rept. 

 63: 33. 1883. {B. pobjstachya major, Vasey Rept. Wheeler's Surv. 6: 287. 1878.)' 

 ROTHROCK'S GRAMA.— A densely etespitose perennial, with erect simple or 

 sparingly branched leafy culms 3-6 dm. (10-2°) high, and five to nine more 

 or less spreading, densely flowered spikes 2-3 cm. (I'-li') long Leaves 

 mostly plane, 5-10 cm. (2'-4') long, thinly pubescent near the base. ' Spikelets 

 3-4 mm. (li"-2") long; empty glumes (o) unequal, the second (6) prominently 

 mucronate between the unequal lobes, much exceeding the first but shorter 

 than the floret; flowering glume [c, d) deeply 4-lobed, lobes ciliate, nearly 

 equal, the awns equaling or exceeding the glume; teeth of the palea (e, e') cili- 

 ate. Its awns shorter than those of the glume; pedicel of the rudiment (/) 

 villous-tufted, the awns usually longer than those of the flowering glume — 

 Sandy plains, mesas, and foothills, Arizona. (Mexico.) August, September 

 20801— Xo. 7 14 



