490 



the lofty savannahs of the hills terminate in a 

 zone of shrubs, which by their appearance, 

 their tortuous branches, their stiff leaves, and 

 the dimensions and beauty of their purple flow- 

 ers, remind us of what is called in the Cor- 

 dilleras of the Andes the vegetation of the para- 

 mos and the punas *. We there find the family 

 of the alpine rhododendrons, the thibaudias, 

 the andromedas, the vacciniums, and those be- 

 farias with resinous leaves, which we have seve- 

 ral times compared to the rhododendron of our 

 European Alps. 



Even when nature does not produce the same 

 species in analogous climates, either in the 

 plains of isp thermal parallels -jf, or on table- 

 lands the temperature of which resembles that 

 of places nearer the poles we still remark a 



* An explanation of these words has been given in vol. ii, 

 p. 252, note. 



t We may compare together either latitudes which in the 

 same hemisphere present the same mean temperature (as, 

 for instance, Pennsylvania and the middle of France, Chili 

 and the southern part of New Holland) ; or consider the re- 

 lations, that m,ay exist between the vegetation of the two 

 hemispheres under isothermal parallels (of the same heat). 



J The geography of plants not only examines the analogies 

 observed in the same hemisphere, between the vegetation of 

 the Pyrennees and that of the Scandinavian plains ; between 

 that of the Cordilleras of Peru, and of the coasts of Chili ; 

 it discusses also the relations between the alpine plants 

 of both hemispheres. It compares the vegetation of the 

 Alleghanies and the Cordilleras of Mexico, with that of the 



