Miscellaneous Publication 423, U. S. Dept. of Agriculture 



Plate 17 





Canotia holacantha in the Harcuvar Mountains, Yuma Count v, altitude 2,500 

 feet. A leafless tree about 15 feet high. The bladdery calyces of Salazaria 

 mexicana, a common desert shrub, show in the foreground. 



