Arctic Plants: Geographical Distribution 111 B 



epoch. It seems strange that no species of Trifolium has reached the polar 

 regions, nor seemingly developed there, although the high alpine section Lupin- 

 aster might be well adapted to these regions. I think especially of the American 

 Trifolium nanum Torr., T. dasyphyllum T. et G., and T. Parryi Gr., the South 

 European T. alpinum L., and the Siberian T.Lupinaster. T.alpinum is a, native 

 of the Pyrenees, the Alps of Switzerland, and the South German mountains; 

 T. Lupinaster is widely distributed in northern Siberia, principally in the moun- 

 tains: Ural, Altai, Baikal, and Davuria. The American species, on the other 

 hand, are endemic to the Rocky mountains. We -have thus in the genus Trifolium 

 a section which has developed in mountains very far apart and which has pro- 

 duced some few species of exactly the same habit, similar to the case in the 

 genus Sieversia. 



Recorded from all the regions marked on the geographical Table 1, with the 

 only exception of the Himalayas, Empetrum nigrum is thus circumpolar, and 

 widely distributed farther south throughout the northern hemisphere; more- 

 over, it follows the Andes in South America to the antarctic region, but is absent 

 from the other parts of the southern hemisphere. On the west coast of Green- 

 land i^mpefrwrn extends as far north as 78° 18' N. L., Foulke fjord (Hart); on the 

 east coast it has been found at 74° N. L., Clavering island (Dusen), and in Spitz- 

 bergen at about 78° 30' N. L. (Nathorst). It deserves mention that Dusdn 

 (I.e.) found it with flowers, partly hermaphrodite and partly dioecious (pistillate), 

 and also with fruits from the previous year at Cape Parry, about 72° 30' N. L. 

 In Spitzbergen it was collected in full bloom in the latter part of July by Gunnar 

 Andersson and Hesselman (I.e.), and the flowers were partly hermaphrodite, 

 partly pistillate; however, some fruits from the year previous, still attached to 

 the branches, were,withered and contained no stones, thus the authors conclude 

 that the plant is sterile in Spitzbergen. As Nathorst and Gunnar Andersson 

 succeeded in detecting several well developed stones of the fruit in the Mytilus 

 strata on this island, it seems probable that deterioration in climate since the 

 deposition of the said strata caused the present sterility of the species. 



The two species of Epilobium, E. angustifolium L., and E. latifolium L., 

 collected on the arctic shore, are both of the section Chamaenerion ; two others, 

 E. Dodonaei Vill., and E. Fleischeri Hochst., are natives of the Alps in Switzer- 

 land, the former also of the Pyrenees and Caucasus. While E. angustifolium 

 and E. latifolium accompany each other in the arctic region, the former shows 

 the widest distribution farther south; they both, however, have reached the 

 Himalayas, the Altai arid Baikal mountains, and the Rocky mountains as 

 far south as Colorado; but only the former occurs also in the European Alps, 

 the Pyrenees, Caucasus, and arctic Scandinavia. In the United States E. angusti- 

 folium is very common in low grounds, in clearings and newly burned lands, 

 from the Atlantic to the Pacific; in Canada, it extends from Labrador west to 

 the Pacific and Alaska, and north to the arctic shore. E. latifolium is in the 

 United States confined to the Rocky mountains and N. E. Oregon, while in 

 Canada it is very widely distributed from east to west, reaching the shores and 

 islands of the Arctic sea in every degree of longitude. 



With regard to the distribution in East Greenland, E. latifolium was found 

 by Dusen at 74° 30' N. L., while in West Greenland it reaches 78° 18' N. L., 

 Foulke fjord. E. angustifolium, on the other hand, is less frequent, occurring on 

 the west coast between 60° and 72° N.L., on the east coast between 60° and 63° 

 30' N. L. But characteristic of both is the fact that several varieties have been 

 observed, especially on the west coast, however. 



Considering the fact that the seeds are remarkably well fitted for dissemina- 

 tion by the wind, it seems natural that the species have become distributed so very 

 widely. But it seems impossible to decide the location of*their geographical 

 centre. They both are circumpolar and, as far as concerns E. latifolium, it may 

 have originated in the north, in the polar regions, or close to them. Otherwise 



