Arctic Plants: Geographical Distribution 



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exemplified farther south in the mountains as well as in the lowlands. Moreover, 

 as stated by Bentham and Hooker, the genus is decidedly a northern, principally 

 mountainous, or even alpine one. A marked characteristic of the genus is the abilijty 

 to produce species endemic to the mountains where it grows; for most of these 

 endemic species are inhabitants of the mountains. The following instances may 

 be mentioned. Of the 31 species known from North America 18 are endemic; 

 29 species are recorded from Altai, 14 of which are endemic; of the 22 species 

 recorded from Central Europe, 11 are endemic; of the 10 species recorded from 

 Caucasus, not less than 8 are endemic; of the 9 species recorded from the Pyre- 

 nees, 2 are endemic; but of the 22 species known from Baikal only 2 are endemic, 

 and a corresponding small number is represented by Davuria with its 21 species 

 only 3 of which are endemic. In other words, the Altai mountains and Cau- 

 casus represent the most important centres of the development of the genus into 

 species. Another important centre is the Rocky mountains and the Coast 

 mountains where several species have developed; Central Europe, especially 

 the Alps, constitutes also a centre of importance. But, although Baikal and 

 Davuria are rich in species of the genus, most of them are also natives of the Altai 

 mountains. As far as concerns Scandinavia with its relatively large number of 

 arctic plants in general, the genus has, as far as it appears, not developed there 

 for there is no endemic species of the genus and, on the whole, the number of 

 endemic species of other plants is surprisingly small in Scandinavia, considering 

 the composition of its flora with so many different types inhabiting the seashore, 

 the valleys, the mountains with their wooded belts and barren summits. And 



