Flowering Piants and Ferns from North-Western Greenland. 37 



It is qiiite natural that North-Greenland does not show many 

 Southern limits of distribution. Nevertheless some interesting facts in 

 this respect may be pointed out. The endemic Braya Thorild-Wulffii 

 occurs only on the north coast and on Germania Land, thus having 

 a southern Hmit, at ca. 76° N., and the same distribution is shown by 

 Minuartia Rossii. Farther to the south, but else of the same character 

 does range the area of Taraxacum arcticum^ stopping at ca. 71° N. 

 Draba Adamsii has so far only been found at Inglefield Land and on 

 the north coast, its southern limit being ca. 79° N. Nearly the same 

 area have Ranunculus Sahinei^ Taraxacum hyparticum and Hesperis 

 Pallasii, although reaching southwards to 78°20' N, 



Dryas octopetala argentea^ Saxijraga flagellaris and S. hirciilus have 

 their southern limit on the W. coast at about 76° N. 



Pedicularis arctica and P. capitata occur only on Inglefield Land 

 between 79° and 78°20' N., neither more north- nor southwards. 



The immigration of the flora of Greenland has been the subject 

 of discussion by many authors. I need only mention J. D. Hooker, 

 E. Warming and A. G. Nathorst. The last times it was discussed, 

 were by H. G. Simmons (1913), Theo. Holm (1922) and H. Steffen 

 (1924, 1925). 



Most arctic species are in my opinion older than the ice-age, which 

 accounts for their occurrence in arctic countries of both the eastern 

 and the western hemispheres. They lived in preglacial times in the polar 

 regions and were driven southwards by the increasing cold and the 

 advancing ice-sheet; in that way they arrived to much less northern 

 latitudes of both Eurasia and America. When the chmatic conditions be- 

 came better and theice retreated, the piants advanced again towards north. 



The question if any of the piants survived the ice-age in the arctic 

 countries, and if so, then how many, is very difficult to answer. While 

 Warming as far as Greenland concerns, believed in the survival of a 

 considerable part of the flora, Simmons on the other hånd considered 

 the whole arctic flora as re-immigrated to the arctic regions in post- 

 glacial times. I feel more inclined to go the middle way. The discovery 

 of some (8) species on an ice-free area, but surrounded by inland-ice, at 

 about ca. 81° N. by Dr. Th. Wulff (on the 2nd Thule Expedition^), 

 shows that some species are able to live under more severe conditions 

 than was to be expected, and this faet points in favour of the survival 

 of species in arctic regions during the ice-age. On the other hånd I do 

 not believe this to be the case with the main part of the present flora 



\) See Ostenfeld 19234, p. 267. 



