RECENT DISCOVERIES IN THE SOUTH NORWEGIAN FLORA 253 



propose that it could have immigrated to Norway from the south as late as 

 during the deglaciation. But then, its distribution pattern should have been 

 entirely different. Since the species is totally lacking south of the Jotunheimen 

 Massif (in spite of the fact that there are innumerable suitable habitats for 

 it, for example, on the Hardangervidda, the mountains in ValdresandSogn, 

 all botanically very well investigated areas), but appears far out in the coastal 

 mountains of More, it is virtually impossible to accept the hypothesis that it 

 should have immigrated from the south during the deglaciation. 



Another important example is given us in the distribution of Euphrasia 

 lapponica. Until 1947 this bicentric species had in southern Norway been 

 found only inland, from Hardangervidda in the south to the Opdal Mts. in 

 the north. But in the summer of 1948, I discovered E. lapponica growing on 

 some relatively low mountains far out north of the Romsdalsf jord close to the 

 sea but above the birch region. Besides the ordinary form with a white 

 corolla I found a new race of the species with a deeply blue-violet corolla 

 {Euphrasia lapponica Th. Fr. fil. var. purpureocoerulea Nordh. ; cf. Nordhagen, 

 1952). 



The last example of bicentric species to be mentioned in this paper is 

 Rhododendron lapponicum, a dwarf shrub and the only European representa- 

 tive of the genus Rhododendron indigenous to northern Europe. In Scandin- 

 avia it has a typically bicentric area. A previous report of its occurrence on 

 Bear Island has proved erroneous. The nearest localities of the species outside 

 of Scandinavia is Greenland to the west and Lake Baikal and River Lena to 

 the east. 



The south Norwegian area of this species was very hard to interpret 

 until 1957. Already during the last century it had been located in several 

 places in the northernmost part of Jotunheimen, above the timberhne, in 

 the cantons Vaga and Lom and early in this century somewhat farther west 

 in Skjak but as a real rarity. To Axel Blytt, Rhododendron lapponicum 

 functioned as a cornerstone in his scholarly construction concerning the 

 continental character of the "Arctic flora" element in Norway since it seemed 

 to be confined to areas situated in the rain shadow of the western mountains 

 with their glaciers. 



During the summer of 1957 I started, perhaps by instinct, to investigate the 

 northernmost canton Lesja, in the valley of Gudbrandsdalen. It borders to 

 Romsdalen. Perhaps it was the above-mentioned discoveries of Saxifraga 

 hieraciifolia (Fig. 8) which stirred in my subconscious. Once more fate was 

 kind to me. In Lesja a lady told me that in 1945 an Enghsh salmon fisherman, 

 Mr. Jack, had divulged to her the precise locality of Rhododendron 

 lapponicum southwest of Lesjaverk. I was accompanied on this occasion by 

 Curator R. Berg, and thanks to our combined efforts we succeeded in re- 

 locating Mr. Jack's locaUty, and even found a new one near by. 



Berg and I returned later to the mountains of western Lesja in the summer 



