HISTORY AND AGE OF SOME ARCTIC PLANT SPECIES 215 



polar Arctic-Sub-Arctic distribution. Part of it reached even some relatively 

 adjacent mountain ridges in the nearest continents. There it has a pronounced 

 relic character with species like Ranunculus pygmaeus and Saxifrago nivalis. 

 The whole group is represented in Scandinavia and Iceland. 



In Spitsbergen the following species belong to this group: Phippsia algida, 

 Festuca Richardsonii ssp. cryophila. Carex subspathacea, Carex saxatilis, 

 Juncus higlumis. Koeniga islandica. s.l., Tofieldia pusilla. Sfel/aria humifusa. 

 Ranunculus hyperboreus. Cardamine bellidifolia, Draba alpina, Saxifraga 

 hirculus. Cassiope tetragona, and others. 



Some of them, like Cassiope tetragona, seem to be Preglacial. 



3. THE CIRCUMPOLAR ARCTIC GROUP 



This is another group of the Eoarctic species adjusted to Arctic conditions 

 but not occurring in the Sub- Arctic regions. In Scandinavia it has a centric 

 distribution, but it is more or less lacking in Iceland. 



Its age may be Late Pliocene or Early Pleistocene. To this group belong, 

 for example. Equisetuni scirpoides. Hierocliloe alpina. Arctagrostis latifolia, 

 Poa arctica. Carex misandra, Luzula nivalis, Melandrium apetalum. Braya 

 purpurascens. Draba lactea, Pedicularis hirsuta. and other species. 



4. THE CIRCUMPOLAR HIGH ARCTIC GROUP 



The Eoarctic species of this group are very old — probably from the 

 Pliocene. Dupontia Fisheri and Pleuropogon Sabinei belong to the endemic 

 genera in the Arctic. I think that the occurrence o^ Pleuropogon in Altai is due 

 to migration from the Arctic. Whether Pleuropogon originated in Beringia 

 (as assumed by Roshevizh, 1952) or in another part of the Arctic cannot be 

 proved at present. 



Some of the plants have their nearest relatives in the Eurasiatic or American 

 mountains. Thus, for example. Saxifraga setigera has a related species in 

 central Asia; Eutrema Edwardsii has one in Altai and Sayan mountains; 

 Festuca brachyphylla one in the mountains of North America. They came 

 very early to the Arctic and completed their circumpolar distribution during 

 the Ice Ages. 



Alopecurus alpinus must be an old species. It occurs in Scotland but not in 

 Scandinavia; it has been found in the stomach of the Siberian mammoth 

 (Tikhomirov and Kupriyanova, 1954). In Scandinavia, some of the species of 

 this group have formed related species or subspecies probably during the 

 Last Glaciation: Arnica angustifolia has a very closely related species in 

 Scandinavia, Arnica alpina: Melandrium furcatum has a near relative, M. 

 angustiflorunu in Scandinavia and western Siberia. 



Besides the species mentioned we can include in this group, e.g. Deschampsia 

 breiifolia, Poa abbreriata, Puccinellia angustafa, Draba subcapitata, and 

 several others. 



