SURVIVAL OF PLANTS ON NUNATAKS IN NORW^AY 



267 



2. The West Arctic species Areimria humifusa is known from several locali- 

 ties in the Sarek Mts. on the Swedish side of the border and, so far, from a 

 single, isolated locality farther south. It is a northern unicentric species. 

 According to Polunin (1943) the nearest locality is on Spitsbergen, and beyond 

 that no closer than east Greenland. 



Fig. 7. The distribution in southern Norway of Papaver ladicatum ssp. ovatilobwn 

 (dots) and P. relictuin (crosses) (after Nordhagen 1936). 



3. Another West Arctic and northern unicentric species, Draba crassifolia, 

 is also found in several localities in the same areas on both sides of the 

 boundary. 



4. At Lake Balvatnet is found Saxifraga aizoon. In Norway it is found 

 furthermore in a restricted area in the southernmost mountains (Ryfylke). 

 Nordhagen (1936) has shown that the southern population is identical with 

 the central European S. ai-oon, whereas the population at Lake Balvatnet is 

 so different that it must be given the rank of a subspecies ; thus it is endemic 

 to this area. The occurrence and the taxonomical difference can only be 

 explained by the theory of survival. 



5. In 1942 the Swedish botanist Sten Selander discovered in the Sarek Mts., 



