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



PLATE 2 



Succulent desert on a coarse out wash plain in the Tucson Mountains, Pima 

 County, altitude 2,200 feet, with Cere us giganteus, Olneya tesota (right), Cer- 

 cidium micro phyllum (center), Celtis pallida (left center), Opuntia fulgida (right 

 center). The low shrubs are Franseria deltoidea. 



