216 EMIL HADAC 



5. THE ARCTIC-SUB-ARCTIC AMPHI-ATLANTIC GROUP 



The "Amphi- Atlantic element" is very heterogeneous and should be divided 

 into more homogeneous sub-groups. This group is at home in the Arctic and 

 Sub-Arctic, but not in central Europe. It has crossed the Atlantic either via 

 northeast Greenland-Spitsbergen, or via south Greenland-Iceland (or vice 

 versa). In Spitsbergen only a few species belong to this group: Harrimanella 

 hypnoides is probably Preglacial, Deschampsia alpina and Draba rupestris are 

 probably of Early Pleistocene age. 



6. THE ARCTIC AMPHI-ATLANTIC GROUP 



Plant species of this group have their distribution in the Arctic on both 

 sides of the Atlantic. It is probable that they migrated by a northern land 

 connection, i.e. via Greenland-Spitsbergen-Novaya Zemlya or vice versa. 

 This land connection is supposed by Sorensen (1945) to have existed as late as 

 during the Mindel-Riss Interglacial. If this is right, the species of this 

 group must be of Early Pleistocene age. 



Here belong Car ex ursina, extending from Taimyr to the American Arctic, 

 Carex uardina growing from Alaska to Novaya Zemlya and Scandinavia; 

 Campanula imiflora and Papaver Dahliamim ssp. Dah/iaiium have a similar 

 distribution. Minuartia Rossii reaches from its Arctic American area to 

 Spitsbergen but not farther. 



In this group I have also included Eriophorum triste, but recent records 

 seem to speak for its inclusion in an Arctic Circumpolar group (No. 3). On 

 the other hand, Cerastium Regelii probably belongs here rather than to the 

 third group. 



7. THE EUROPEAN ALPINE-ATLANTIC GROUP 



The origin of these species lies in European mountains, in the Alps, the 

 Pyrenees, or the Carpathians perhaps as early as the Pliocene or even before. 

 Anyway, in early Pleistocene they were well established, "mature" species. 

 During the Ice Age they descended from the mountains, forming a part of the 

 leading vegetation type of this time, the tundra. In the "Dryas flora" of the 

 Riss deposits in, for example, Poland (cf. Srodoh, 1954), were found 

 Arahis alpina, Betula nana, Salix herbacea, S. reticulata, together with several 

 species of the Circumpolar Oreo-Arctic group. Following the retreating ice- 

 shield they came to Scandinavia, Iceland, Greenland, and Arctic America, 

 to western Siberia, Novaya Zemlya, and Spitsbergen. 



To this group in Spitsbergen belong: Salix reticulata, S. herbacea, Betula 

 nana, Beckwithia glacialis, Arabis alpina, Saxifraga aizoides, Potentilla 

 Crantzii. Poa alpina vivipara, and perhaps Festuca vivipara. Empetrum 

 hermaphroditum seems also to belong to this interesting group as may be seen 

 from the map in Vassil'ev's (1961) recent monograph. 



