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O. GJ.CREVOLL 



Norwegian Papa ver-populations as seen in the light of recent cytological 

 investigations (Fig. 7). 



This concentration of rare species in two widely separated areas cannot be 

 accidental. As we have seen, the species belong to entirely different geographi- 

 cal elements, partly they are West Arctic, partly Arctic-Alpine, partly Asiatic, 

 partly endemic. 



Fig. 6. The total distribution of Scirpus pumilits (after Hulten, 1958). 



With regard to the poppies, Nordhagen (1931) has drawn the conclusion 

 that their peculiar distribution cannot be explained by Post-glacial migration, 

 but more likely is the result of survival in separate refugia along the west 

 coast of Norway. The present distribution of the poppies indicates that there 

 must have been several refugia. This leads to still another question: is it 

 possible from the present-day distribution of the species to delimit the refugia 

 more exactly? We know that plants are able to disperse — in some cases very 

 rapidly — but we also know, for instance from the Alps, that relic species may 

 be so depauperated that their ability to disperse is strongly reduced. 



In 1935, Nordhagen gave a very striking example indicating a refugium in 

 the district of Nordland. I want to recall this example, supplemented by some 

 recent observations. The map (Fig. 8) shows the concentration of a number of 

 rare species east of the Salten Fjord in the area of the Swedish-Norwegian 

 boundary. 



1. A short distance south of this area there is a peculiar Papaver locality, a 

 local endemic, Papaver radicaUnn ssp. siihg/ohosiini. 



