228 KNUT F^GRI 



plants were crowded out from the flat lands in Denmark and a large part of 

 south Sweden is generally accepted. But one should not forget the persistence 

 of Glacial-Alpine elements in the flora both of the steep mountains in 

 south Sweden (Omberg. Hesselman, 1935; Kinnekulle, Albertson, 1940) 

 and the flat, thin, poor limestone soils of Oeland (Sterner, 1938). On the 

 whole, however, very little is left, and the problem has been raised whether 

 the peri-glacial Ice Age flora had any chance to reach the Scandinavian 

 mountains this way. The absence of fossils of Arctic plants between south 

 Sweden and Jamtland has been mentioned although the argument is perhaps 

 not too convincing. Its value depends on how much has been done in order to 

 find such fossils. There is no doubt that the climate was sufficiently con- 

 genial for a forest vegetation to follow very close to the ice edge. But dimen- 

 sions are diff'erent in biology and geology: "very close" and "very fast" in a 

 geologic sense may still leave plenty of place and time for Arctic plants to 

 colonize. And besides, the bee-line route from Scania to the central Scandin- 

 avian mountains was not the only possible route: if Arctic plants were able to 

 reach the outer part of the Oslo district (outside the Ra end-moraine line), 

 they would also have very good possibilities of spreading towards the moun- 

 tains this way. It should not be forgotten that Alpines still grow at low 

 altitudes in the Oslo region (Dryas, Carex nipestris in Solbjergfjell, Lid, 1958; 

 Arctic species in Krokkleiva, etc.). Without insisting that these plants must be 

 true relics from the Late-Glacial (or rather pre-Boreal, as the areas were 

 ice-covered until then), we may safely state that no other explanation of their 

 presence is more convincing. 



Before proceeding with the Arctic-Alpine species I should like to draw 

 attention to the so-called xerothermic element of the flora of southeastern 

 Scandinavia. In Oeland it grows intermingled with Arctic-Alpine plants, and 

 the problem is how great a part of this element immigrated during the Late- 

 Glacial, and how great a part during the presumed xerothermic later period. 

 A plant like Coronilla emerus might well be a Late-Glacial relic, occurring 

 today in Oeland and at one station on the Norwegian southeast coast. 



Returning now to the Arctic-Alpine plants of south Norway, my main 

 thesis would be that unless immigration via the Oslo area can be definitely 

 ruled out, there is nothing in dispersal to prevent the mountain flora of 

 south Norway from having been recruited from the flora surviving at the 

 southern edge of the ice. Which, of course, is no proof that it has been 

 furnished that way. 



Whatever are the concepts about ice limits farther north, there can be no 

 doubt that Norway south of 61° N. Lat. was completely ice-covered, cf the 

 date 13000 B.P. for a chionophilous ice-edge community at Jaeren or 12500 

 B.P. for a sub-moraine deposit at Blomvaag (Nydal, 1960) at the extreme 

 edge of the land towards the sea. The ice edge must have gone far out in the 

 sea. Nevertheless, the Jaeren deposit exhibits a typical Arctic- Alpine flora 



