USEFUL WILD PLANTS 



families go to the Mils and camp out in the Nopaleros 

 (the areas where the cactus grows) and live prac- 

 tically upon tunas alone. Mr. David Griffiths, in his 

 monograph "The Tuna as a Food for Man," ** states 

 that at such times about two hundred tunas a day 

 constitute the ration of one individual. Large 

 quantities are dried for future use and several pro- 

 ducts are also manufactured from the fresh fruit. 

 One of these, called queso de tuna (that is, "tuna 

 cheese"), is an article of sale in the Mexican 

 quarters of our Southwestern towns. It is made by 

 reducing the seeded tuna pulps to an evaporated 

 paste, and is sent to market in the shape of small 

 cheeses, dark red or almost black. 



Another member of the Cactus family that is an 

 important food source in the Southwest is the 

 Sahuaro (Cereus giganteus, Engelm.). It is 

 Arizona's floral emblem, and abounds throughout 

 the southwestern part of that State and across the 

 frontier into northern Mexico, forming at times in 

 the desert strange, thin forests casting attenuated 

 shafts of shade. It is one of the world's botanical 

 marvels, a leafless tree with fluted, columnar trunk 

 and scanty, vertical branches, rising sometimes to 



6 Bull. 116 Bur. Plant Industry, U. S. Dept. Agriculture. 



110 



