ICE AGE REFUGIA IN ICELAND 



319 



3. The Austfirdir district comprises the true Austfirdir and the mountain 

 range behind the fjords from the Heradsfloi in the north and southwards to 

 Hornafjordur. In close connection to the main district is the Austur-Skafta- 

 fellssysla as a whole. 



The great majority of the West Atlantic group is found here, and Cerastium 

 Edmondstonii has its chief center here. All the North Atlantic plants occur here 

 too, and two of them, Alchemilla faero^nsis and Saxifraga Aizoon, have their 

 main centers here. Plant-geographically speaking, there is an obvious relation- 

 ship between the Austfirdir and the Eyjafjordur districts. None of the central 

 species is a real alpine plant. 



In this district, 6 species are monocentric, i.e. Aspleniuni riride, Lycopodium 

 clavatiinu O.xalis acetosella, Saxifraga aizoides (Fig. 19), Saxifraga cotyledon, 

 and I'accininni vilis-idaea. and none of them is found outside the district 



Fig. 19. Saxifraga aizoides. 



except Vaccinium litis idaea which occurs in the nunatak area in north- 

 eastern Iceland, where Roegneria doniana var. Stefanssonii is also found. 

 Last year. Asplenium triciwmanes was found in the Orccfi district, and it may 

 possibly also be an overwinterer. 



Four species are bicentric: Ranunculus auricomus, Trientalis europaea, 

 Carex pulicaris, and Populus trenmla. and finally there are 2 tricentric, or 

 perhaps rather polycentric. species: Campanula rolundifolia and Carex 

 pi lu I if era. 



4. The Myrdalur and Hvalfjordur districts have few distinctly centric species, 

 and none of them will be dealt with specifically here. On the whole, the 

 Myrdalur district may be considered a dubious refugium area. 



