Bui. 201, U. S. Dept. of Agriculture. 



Plate III. 



fig. 1.— bouteloua rothrockii under protection just below the northern 

 Foothills of the Santa Rita Mountains, Ariz. 



Fig. 2.— Bouteloua Aristidoides in a Favorable Season on Desert Mesas, South 



of Tucson, Ariz. 



