1 92 1. No. 7. STUDIES ON THE LICHEN FLORA OF NORWAY. 21 



Europe, and they art more or at least quite as much southern and western 

 as eastern plants. 



They are evidently southern plants that require much warmth for their 

 development, but they can endure severe winter temperatures. Their 

 occurrence in Central Europe indicates the same. Their distribution in our 

 countr\- is not easily understood. Are they relics from better times? 



2. Subalpine lichens. 



We have alreadv mentioned that our subalpine and alpine lichens are 

 more clcsely related with eastern than with western and southern floras. 

 It is then easily understood that many subalpine lichens also in our country 

 are more eastern than western. 



We must not overlook the fact that the great woodless western 

 districts are not well adapted for many subalpine lichens. But there are 

 also subalpine plants which are not forest plants, and which are rare or 

 lacking in Western Norway. 



The above mentioned eastern lowland Norwegian lichens have a con- 

 tinuous distribution up to Dalsland and the Swedish west coast. But if 

 we will follow the distribution of many of our most typical eastern sub- 

 alpine lichens in Sweden we must go farther north, to the subalpine forests 

 in Herjedalen and Jemtland. 



In Norway they are distributed over large parts of the continental 

 Eastern Norway and many of them are common in Nordland, (as far as 

 we know), Troms and Finmark. 



The type plants is Akctoria Fremoiitii, our largest dark Beard lichen, 

 distinguished by its yellow soredia. It has been recorded from the Pasvik 

 valley in Eastern Finmark, it is abundant in the inland part of Maalselven 

 in Troms, still more abundant in Northern Østerdalen, and not common in 

 the Nordmark and Hadeland forests. There an besides a few scattered 

 stations in Western Norway just over the mountains, especially at and near 

 Voss, where many eastern plants occur. 



Other lichens are quite as typical: Akctoria siuipUcior, PanneUa 

 fraiidaiis, Stcrcocaiiloii foiiic/ifosiaii, C/adoiiia acimiiiiata, and Lctharia vulpina. 

 The latter has only been recorded in the Tryssil-Fæmunden \alley and at 

 a few stations in Upper Gudbrandsdalen. 



Four of these six lichens are lacking in the British Isles, and the 

 other two are 'local and scarce'. 



Paniu'lia ceiitrifiiga and Cladonia alpcstris are widely distributed and 

 very common plants in subalpine eastern districts, but their vertical range 

 is wider than the subalpine region. 



In Eastern Norway the former occasionally extend to the level of the 

 sea, and it ascends considerably above the upper forest line. It is lacking 

 on the west coast, and rare at the western Ijords down to 400 m. s. m.. 



