PHYTOGEOCIRAl'HIC AL PROBLEMS IN SVALHARD 103 



truly Arctic species, and are confined to more temperate or Low Alpine 

 regions, e.g. in Scandinavia. This greater demand for a mild climate could be 

 the reason why they occur today in Svalbard only on Bear Island. 



ENDEMIC SPECIES 



It is generally assumed that the frequency of endemic plants within a 

 flora is an indicator of its age and of a long-time isolation. If the flora of 

 Svalbard has been isolated for a considerable length of time, the occurrence 

 of endemic species within the Svalbard area must be expected. During the 

 last years, in the course of my investigations concerning the flora of Svalbard, 

 I have discovered, as far as I can see, that such an endemic element exists, 

 comprising plants ranking both as species and as taxa of lower rank such as 

 varieties. It is in this respect first necessary to look upon the Svalbard flora 

 separately. Here we have two species endemic to that area, viz. Puccinellia 

 sialbardensis Ronning and Ranunculus spitsbergensis Hadac. Besides there are 

 two endemic varieties, viz. Puccinellia angustata var. decwnhens and Colpodium 

 vahlianuni var. pallida. 



However, the two groups of islands, Svalbard and Novaya Zemlya, are 

 closely related both geographically and floristically. Many plants are common 

 to the two areas, but Novaya Zemlya, especially in the southern part, has a 

 greater number of eastern plants than Svalbard. Their phytogeographical 

 connection is further emphasized by the fact that within Novaya Zemlya and 

 Svalbard taken as one unit, there are some endemic plants: Pedicularis 

 dasyantha, Colpodium vacillans and Puccinellia phryganodes of the Spitsbergen 

 type (in the sense of Sorensen. 1953, and Ronning, 1962) are examples of 

 such species, endemic to this larger area. 



It is thus possible to separate two areas, the larger comprising both Svalbard 

 and Novaya Zemlya, and the smaller one only the Spitsbergen Archipelago. 

 It is not possible to say exactly how the isolation has taken place, but the 

 endemic plants mentioned give a true indication that these areas once did 

 exist. It is also very likely that even more endemic plants, ranking either as 

 species, subspecies, or varieties, will appear as the investigation of the 

 Svalbard flora continues. This is even more probable since such taxonomically 

 difficult genera as Draba, Potent ilia, and Poa have not yet been thoroughly 

 worked out, and some of their varieties may turn out to be endemic to the 

 area in question. 



THE CONNECTION BETWEEN THE FLORA OF NORTHERN 

 SCANDINAVIA AND THE ADJACENT ARCTIC REGIONS 



The greater part of the plants common to Svalbard and northern Scan- 

 dinavia have a wide distribution and must be regarded as ubiquitous in 

 Svalbard or at least in the Spitsbergen area. Examples of such plants are 

 Equisetum vaviegatwn. Deschampsia alpina. Salix polaris. Oxyria digyna. 



