INTRODUCTORY ESSAY, 107 



Flora predominates throughout the drier regions of the Hima- 

 laya"*. Siberian forms are, however, by no means confined 

 to the drier parts of the chain, but may be observed even in 

 the most humid regions of the Himalaya, and occasionally 

 even on the mountains of tropical India. Thus Artemisia and 

 Astragalus, which are perhaps the most characteristic genera 

 of the Siberian type of vegetation, are not only abundant 

 throughout Tibet and the interior Himalaya, but are repre- 

 sented by a few species in the plains of the Panjab, on the 

 outer slopes of the western Himalaya, and even on the Khasia 

 mountains. Spirted Kamtchaiica, chamadrifolia, and sorbi- 

 folia, and Paris polyphylla, are also Siberian forms which 

 extend into the rainy Himalaya ; and Corydalis Sibirica and 

 Nymphaa pumila are remarkable instances of specific identity 



between Khasia and Siberian plants f. 



5. The European type. — The extent to which European 

 plants abound in India has never hitherto been even approxi- 

 mately appreciated. Dr. Royle was the first to indicate this 

 affinity between the vegetation of the eastern and western 

 continents of the old world ; and throughout his writings we 

 find constant evidence of his never having lost sight of this 

 being a marked feature. Had the collections, upon which he 

 founded his conclusions, been critically compared and worked 

 out, the keystone to the whole system of distribution in 

 Western Asia could not have escaped him, which does not 

 rest so much upon a number of representative species, as 





instances 



mm 



tnultifidi 



rus baccata, Astragalus contortuplicatus, densi 

 *a frigida, Oxytropis diffusa, Clcer Soongaricum 



Sedum 



Mulgedlum 



(Rhododendron 



micro 



and tristis. 



ria a certain number of forms 

 Memspermtim and Anandria. 



