The Flora of Greenland and its Origin. 49 



and a few species of Carex and Piiccinellia may be supposed 

 to have been brought by the ocean currents (Lathynis 

 maritimus and Atriplex are considered as having been 

 brought by the Norsemen). But the importance of water 

 in a frozen state must on the other hånd be particularl}' 

 emphasised. Where the sea ice Ues firm throughout the 

 winter, it forms a splendid field for the transport of wind- 

 borne seeds and fragments of piants; moreover, the wind 

 at that season is often very strong. The distance across 

 Smith Sound for instance, is a mere nothing when the 

 sound is frozen over. 



Where sea ice is carried along by currents, as is particul- 

 arly the case on the East Coast of Greenland, it will also 

 doubtless be able to carry portions of piants from other 

 countries; this would explain the occurrence of eastern 

 species in northern East Greenland. Several of the peculiar 

 species moreover (e. g. Polemonium boreale, Arenaria pseudo- 

 frigida) are positively restricted to the extreme coastal 

 districts, which seems to argue in favour of this mode of 

 immigration. 



The importance of the wind in spreading seeds through- 

 out these regions is doubtless very considerable, especially 

 in winter, when the snow, or as just noted, the ice, covers 

 the surface. Nearly all the piants found in Greenland have 

 rather small seeds; only a few (some of the Compositæ, 

 Salices, Eriophonim, Epilobiiim and Dryas) have special 

 adaptation for wind transport in the form of hairs and 

 pappus. 



It is characteristic in this respect that several plant 

 families in which the seeds or fruits are as a rule compara- 

 tively large, and without special aids to transportation, are 

 altogether lacking in the tlora of Greenland, though they 



Videnek.Selsk.Biol.Medd.VI. 3. 4 



nm 



