EUPHOR B IACEAE 



crannies and cracks and are very effective in opening up the rocks. 



"While this plant nay not, or .nay be important in erosion control in 

 •warm parts of Arizona, it is worthy of careful experimental work as 

 a crop not only for Indians but for whites as well. 



Jatro pha c ardi ophylla occurs only in Arizona within the Uni- 

 ted States but is common in Sonora. It is a lovf, very tender shrub 

 likely to freeze to the ground in winter evon in the foothills about 

 Tucson. The loavos are rather small and heart-shaped and the stems 

 peculiarly pliable, giving one the impression of being rubbery. The 

 plant grows in the driest, rockiest of sites. It is never eaten 

 and has little value as an erosion control plant but the dried roots, 

 according to Standley, contain much tannic acid, thus suggesting the 

 use of the shrub as a commercial crop in the extreme desert regions 

 of Arizona. It has long been used for tanning and probably for dye. 

 Owing to trie color of the juice the plant has been called Gangre de 

 Cristo. 



Jatropha spathulata is a tall shrub somewhat resembling in 

 habit the Sapium described above. It occurs in western Texas and 

 southwestern Arizona and far south into Mexico in the driest, rock- 

 iest of sites. It will withstand very little frost. As an erosion 

 control plant it is probably of little value but owing to the various 

 uses to which it has been put in the past it is possible that it nay 

 prove of value as a commercial crop in regions which produce curious 

 tilings but which take their own sweet time in which to do it. It 

 is almost a foregone conclusion that crops cannot be grown in regions 

 of two to five inches of rainfall and harvested every year. It is 

 not evident, however, that valuable crops such as tannin, dyes, 

 alkaloids, gums and resins cannot be harvested every five or ton 

 years and the plants not exploited to the point of extermination. 

 Vfeeds and diseases are not troublesome in the desert and frequent 

 cultivation is hardly desirable. All that is necessary is to give 

 God and the desert a chance. The branches of this plant have been 

 used in basketry and the baric was formerly exported from Mexico 

 for tannin and for a dye. The plant has been used medicinally for 

 everything from toothache to syphilis. It is highly probable that 

 the chief product worthy of investigation is the tannin. 



Jat roph a angustidens , Mala mujer, is not reported by Standley 

 as occurring in Arizona. It is, however, very common in Pima and 

 Santa Cruz and Cochise Counties in the foothills. With us it is 

 herbaceous, dying down completely to the roots each fall but forming 

 in the summer a dense bush-like plant one to three feet high. Once 

 seen it can never be confused with another plant. The leaves arc 

 clothed with white shiny, stiff hairs above, below and along the 

 edges; the stems are similarly clothed and even the flowers and 

 fruits. The loaves arc large and the whole plant makes a striking 



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