On the Genus Antennaria in Greenland. 281 



As regards the probable age of the above mentioned species of An- 

 tennaria in Greenland, A. alpina is so widely distributed, that it must 

 be considered as belonging to the oldest types of the flora, which may 

 have migrated over Smith Sound shortly after the glacial period, and 

 which has later been ousted from a part of its territory in the North 

 by the present period of more severe climate, which followed an earlier 

 and milder postglacial climate. 



Until A. glabrata has been found in other places, it is most natural 

 to consider it a species of recent origin or perhaps still in the making, 

 originated in Greenland, and consequently one of the very few endemic 

 species of this big island. Perhaps the same is the case with A. inter- 

 media, whereas its nearest relation A. groenlandica belongs to the large 

 group of American species, which have also migrated to the South of 

 Greenland: but all explanations of this migration are as yet only loose 

 hypotheses. 



Reference can here be made to the interesting treatment of this 

 very important problem of the Arctic plant geography, recently given 

 by H. G. Simmons in his paper "A Survey of the Phytogeography of the 

 Arctic American Archipelago", Kgl. fysiograf. Sällsk. Handl. N. F. Bd. 24^ 

 No. 19, Lund, 1913. 



Disko, Godhavn, Nov. 1913. 



