ICE AGE REFUGIA IN ICELAND 



317 



Besides these plants 22 species are found to have their chief distribution 

 in the Vestfirdir district. In contrast to the Eyjafjordur district all the centric 

 species are lowland plants. 



so <x »» 



Fig. 16. Cornus suecica. 



Fig. 17. Jimciis castaneus (dots), Juncus squanosiis (triangles). 



Carex adelostoma and Cryptogramma crispa are unicentric. Cornus suecica 

 (Fig. 16), Juncus castaneus (Fig. \1), Juncus squarrosus (Fig. \1), Equisetum 

 silvaticum, and Melampyrum sUvaticum are bicentric. The second center of 

 these species is the Austfirdir district, except in the case of Cornus which has 



