110 B Canadian Arctic Expedition, 1913-18 



furthermore, that Astragalus alpinus and Phaca frigida have also reached the 

 Altai, the Baikal, and even the Himalaya mountains; but on this continent 

 these two species do not accompany each other for Phaca stops at the arctic 

 circle while Astragalus alpinus extends as far south as the Rocky mountains in 

 Colorado. Oxytropis campestris, on the other hand, while distributed throughout 

 Canada from Labrador to Kotzebue sound, Alaska, does not follow the Rocky 

 mountains farther south. It would thus appear as if Astragalus alpinus, Phaca 

 frigida, Oxytropis campestris, and Hedysarum obscurum originated in the polar 

 regions, and that the Rocky mountains, the Alps, the Pyrenees, the Altai, and 

 Baikal mountains where the species are still in existence, were reached during 

 the glacial epoch. The arctic distribution of Hedysarum obscurum corresponds 

 well with its occurrence further south, viz.: the European Alps, Ural mountains, 

 Altai and Baikal mountains, and eastern Siberia between Aldan and Okhotsk. 



Among the other species are some genuine American types, viz. : Lupinus, 

 Astragalus polaris, A. aboriginorum, Hedysarum alpinum, H. Mackenzii, 

 Oxytropis arctobia, 0. arctica, 0. Bellii, 0. foliolosa, 0. Roaldi, and Vicia gigantea, 

 some of which are confined to the arctic region of this continent. With regard 

 toOxytropis nigrescens and Heiysxrwn Mackenzii, being natives of ths north coast 

 of this continent as well as of Siberia, these may be looked upon as evidently 

 representing former circumpolar species with a distribution considerably reduced 

 during the glacial epoch. 



A Siberian element is represented by Astragalus chorinensis, Oxytropis 

 Maydelliana, 0. Middendorffii, 0. Mertensiana, 0. Schmidtii, and 0. strobilacea. 

 With the only exception of 0. strobilacea, which has also been collected in the 

 Altai mountains, southwest Mongolia, and western China, the others are con- 

 fined to the arctic region of Siberia, between 69° and 76° N. Lat., from the Asiatic 

 coast of Bering strait to the river Jenisei. 



Then with regard to Europe, its contingent to the arctic flora is relatively 

 small, and Astragalus arcticus is the only species restricted to the urctic zone; 

 it is also a native of arctic Siberia. The other plants are Anthyllis, Astragalus 

 oroboides, Lathyrus pratensis, Orobus, Oxytropis lapponica, Trifolium, Vicia 

 Cracca, and V. sylvatica, all of which are much better represented farther south; 

 with the exception of Astragalus and Oxytropis they are all lowland plants. 



Lathyrus mariiimus, distributed as a seashore plant throughout the northern 

 hemisphere, has reached the arctic region in many places and is, as mentioned 

 above, the only meniber of the Papihonaceae that has reached Greenland. 

 According to its habitat, and being at present much more abundant in the 

 south than in the north, it is evidently a post-glacial introduction in the arctic 

 regions. 



Of the arctic representatives of the Papihonaceae Astragalus and Oxytropis 

 are of special interest. We have in the former two species endemic to this 

 continent, namely: A. aboriginorum and A. polaris; endemic to Asia is A. 

 chorinensis, and common to Siberia and Russia is A. arcticus. Among the 

 thirteen arctic species of Oxytropis five are endemic to this continent, 

 viz.: 0. arctica, 0. arctobia, 0. Bellii, 0. foliolosa, and 0. Roaldi; endemic 

 to Siberia are 0. Maydelliana, 0. Mertensiana, 0. Schmidtii, and 0. 

 strobilacea, while 0. nigrescens is common to Siberia and this continent. 

 As nientioned above, 0. strobilacea is widely distributed farther south in 

 Siberia, Mongolia, etc., and A. aboriginorum is very frequent on this 

 continent in the Canadian west, and northern United States, the prairie 

 region for instance. In other words, the arctic regions of Siberia and America 

 represent some quite important centres of distribution of these genera, and 

 especially of Oxytropis. The species must have originated in these regions 

 and their -present very scattered distribution. may indicate that they have been 

 partly exterminated, the localities having become disconnected during the glacial 



