38 H. G. SIMMONS. [SEC. ARCT. EXP. FRAM 



There is, however, also a number of species so distributed as to 

 make it rather difficult to form a definitive opinion as to whether they 

 are to be referred to the american or to the ubiquitous plants. 



Such are from Group I, 1 : 



1. Arnica alpina, as it seems most widely spread on the Ame- 

 rican side and absent from Southern Greenland. In Ellesmereland it is 

 not found in the Hayes Sound region. 



2. Pedicularis hirsuta, circumpolar but absent from Southern 

 Greenland. 



3. Chamaenerium latifolium, lacking in Western Siberia, Scan- 

 dinavia and Spitsbergen, but appearing in Iceland. If this plant is to 

 be counted as american in Greenland, it should have reached Iceland 

 from the west. Here, however, as in some other cases also, two diffe- 

 rent ways of immigration may be possible. 



4. Potentilla pulchella, only south to the Disco region, and absent 

 from Western Siberia and the European Continent. 



5. P. emarginata, similarly distributed as the last. 



6. Braya purpurascens, circumpolar, but only found about 70 

 in Danish West Greenland. 



7. Eutrema Edwardsii, circumpolar, but very sporadic in Green- 

 land. 



8. Ranunculus affinis, circumpolar, but only in a single place in 

 Danish West Greenland. 



9. Melandrium apelalum, circumpolar, but only spread southward 

 to the Disco region. 



10. Salix arctica, absent from Spitsbergen and the European 

 Continent, and represented in Greenland mostly by the var. Brownii, which 

 is principally american, and the var. groenlandica. 



11. Luzula nivalis, absent from Southern Greenland. 



12. Carex nardina, absent from Arctic Asia and Novaja Semlja, 

 but appearing again in Northern Finland, Scandinavia and Spitsbergen. 



13. Dupontia Fisheri, circumpolar, but only sparingly represented 

 in Greenland, where it is lacking in the south. 



14. Poa abbreviata, most probably an american plant and absent 

 from Asia, but appearing again in Spitsbergen, Franz Joseph Land, and 

 Novaja Semlja. In Danish Greenland its southern limit is at the Disco 

 region, and in East Greenland at Scoresby Sound. 



15. Aspidium fragrans, entirely absent from Europe, and with a 

 northerly distribution in W. Greenland, absent from E. Greenland except 

 for Scoresby Sound. 



