104 OLAF I. RONNING 



Ranunculus pygmaeus, Saxifmga cernua, S. oppositifolia, S. groenlandica, and 

 many others. 



Among the ubiquitous species in Svalbard are also many that in Scandinavia 

 belong to the centric species mentioned above. 



Another group of plants of a striking importance in Scandinavia is dis- 

 tributed mostly along the coast, or not far from the coast, and is common also 

 to the adjacent Arctic islands and northern Scandinavia. The most important 

 members are Arctagrostis latifolia, Arenaria pseudofrigida, Chrysospleniwn 

 tetrandrum. Braya purpurascens, Papaver dahJiamun, and Stellaria humifusa. 

 Though some of them can be found at a distance from the coast or fjord areas 

 in northern Scandinavia, they must all be regarded as lowland plants, and as 

 such they represent taxa with a strikingly different ecology. They are also 

 found farther east in northern Europe reaching as far as the Kola peninsula 

 and Vaygach, but not much farther. In my opinion, also these plants point 

 sometimes to a close connection between the floras of northern Scandinavia 

 and the neighbouring Arctic, and show that this connection includes not only 

 Alpine plants, but also lowland or sea shore plants with an ecology different 

 from that of the Alpine ones. 



To summarize the phytogeographical features of the Svalbard region we 

 may state that: 



1. The number of indigenous species of Svalbard is between 155 and 160, 

 according to the species concept commonly accepted. 



2. Among the species, about 35 have a distinct High Arctic distribution and 

 do not occur on the European mainland, i.e. northern Scandinavia. 



3. Many of the species common in Svalbard are plants having a centric 

 distribution in Scandinavia. They occur either in both southern and 

 northern Scandinavia and Svalbard, or only in northern Scandinavia 

 and Svalbard. or, only in southern Scandinavia and Svalbard. 



4. Groups of species with isolated occurrences in Svalbard are found: 

 (a) in Bear Island, (b) in southernmost Spitsbergen, (c) especially in 

 the inner fjord districts (a larger group with a lower degree of isolation); 

 (d) around the hot springs at the head of Bockfjorden. The existence 

 of this last isolated group is contingent upon the heat of the soil. 



5. Distinct groups of endemic species are found, one endemic to the Spits- 

 bergen Archipelago only, and one endemic to both Spitsbergen and 

 Novaya Zemlya. 



6. A group of plants, not strictly Alpine in northern Scandinavia, also 

 shows a close connection between the floras of the two areas, Svalbard 

 and Scandinavia. 



From the facts presented above it is evident that within the flora of Svalbard 

 distinct groups of plants exist, and that they show a close connection to the 

 flora of the European mainland, i.e. northern Scandinavia. 



