PLATE 10 
A. —A single plant of Allenrolfea inverted on the salt crust to show the char¬ 
acter of the root system. The root extended to a depth of 2 feet. Thermal, 
Calif., March 6, 1915. 
B. —Mesquite and chamiso community. Only the upper branches of the mes- 
quite stand above the sand. The lighter-colored plants contrasting with the 
darker foliage of the mesquite are chamiso bushes. Las Vegas, Nev., September 
11, 1914. 
