218 EMIL HADAC 



10. THE EAST SIBERIAN GROUP 



This group originated probably in the Early Pleistocene in the ice-free parts 

 of eastern Siberia. Salix polaris is known from the "Dryas flora"' of the 

 Rissian Tee Age in Poland, and its arrival in Spitsbergen must have been after 

 the Penultimate Jnterglacial, because it has not reached Greenland. This 

 fits also for most of the other members of this group with the exception of 

 Polemonium boreale and Taraxacum arcticum. 



To this element belong: Phippsia conciniia, Liizula Wahlenbergil, Petasites 

 frigidus. Parrya luidicauJis, Polemonium horeale, and Taraxacum arcticum. 



11. THE GREENLAND-SPITSBERGEN GROUP 

 This group is problematic. It may perhaps be included in the Arctic-Amphi- 

 Atlantic group. Ranunculus Wilanderi and Poa Hartzii might be of Early 

 Pleistocene age. Festuca hyperborea was described recently and therefore its 

 place in this group is provisional. Carex pseudolagopina belongs to C ambly- 

 orhyncha Krecz.. which has a broader distribution and therefore must be 

 removed from this group. 



12. THE NOVAYA Z E M LYA-SP ITS BERGEN GROUP 



The center of origin of this group seems to be in a previous land-mass 

 connecting Novaya Zemlya and Spitsbergen. Some of the species have 

 reached Greenland and Scandinavia {Carex paral/ela, Arenaria pseudo- 

 frigida). Taraxacum brachyceras extends from Vaygach Island to Greenland, 

 but Pedicularis dasyantha grows only in Arctic Siberia, Novaya Zemlya and 

 Spitsbergen and forms thus a transition to the next group. 



J3. THE SPITSBERGEN GROUP OF ENDEMICS 

 This group originated probably in the Late Pleistocene and is therefore the 

 youngest of the Spitsbergen flora. Puccinellia vaciJIans has several locaHties in 

 Spitsbergen and one in Novaya Zemlya. Coptidium spitsbergense, comb, nova 

 (based on Ranunculus spitsbergensis Hadac 1944 in Norges Svalbard og 

 Ishavsunders. Skr. 87, p. 36) occurs in several distant places of Spitsbergen. 

 Its distribution can be explained only by supposing that it already existed in 

 the last Interglacial period. Papaver Dahlianum ssp. Hadacianum is hitherto 

 known only from Spitsbergen. 



14. RECENT IMMIGRANTS 



The only recent natural immigrant seems to be Cakile maritima (or C. 

 cdentulal — there were no fruits!). There are plenty of other species introduced 

 by man. 



The analysis of the Spitsbergen flora shows that most of its species are 

 Preglacial or from the early Pleistocene; only 2.8 per cent are "Neo-Arctic" 

 species from the Late Pleistocene. 



