GNETALES— EPHEDRA 



363 



abundant in the Andes regions of Bolivia and Paraguay, but in 

 Paraguay they also extend across the desert plains even to the 

 Atlantic Ocean. A few are found farther south in ChiH and Pat- 

 agonia. 



In the Eastern Hemisphere, the western hmit is the Canaries and 

 Madeira. There are species in the western Alps, in western France, 

 and in some places along the shores of the Mediterranean and Black 



Fig. 344. — Ephedra: near Palm Springs, California. Ephedra, in this region, often 

 acts as a sand binder. 



Sea. The genus crosses Arabia and Persia, through northern India, 

 and then northeast through China, across the upper basins of the 

 Yang-tse-Kiang and Hoang-Ho rivers. Ephedra distachya gets into 

 Siberia, very far north for a genus which belongs typically to a warm 

 climate. 



No species are common to the Western and Eastern hemispheres, 

 and no species seems to cross the Equator. 



The geographic distribution, with such scattered patches, would 

 indicate great age; but, as already noted, there is scarcely any 

 geological history, no material having been found below the Tertiary. 



