92 B Canadian Arctic Expedition, 1913-18 



the Arctic sea; about Jasper's Lake, in the Rocky Mountains, and, on the west 

 coast, north of lat. 68°, to Ounalashka, Kotzebue Sound, Chamisso Island, and 

 Cape Lisburne, north-east coast of America. It has also been found in Green- 

 land, on the east coast at 72° 30' (Dus^n), on the west coast at 70° (Hartz), but 

 it is absent from Spitzbergen, Scandinavia, and Russia. In Asia it occurs, as 

 stated above, on the north coast: the mouth of the river Lena, and of the river 

 Olenek, besides in eastern Siberia and Kamtchatka. Toward the south it 

 extends to the Baikal mountains. 



Finally, with respect to T. calyculata Wahlenb., this species is more southern, 

 and has been reported from South Russia, the Alps and the Pyrenees, Ural and 

 Kamtchatka; however, it occurs also in Sweden, but only on the island of 

 Gotland. 



Tofieldia palustris and T. coccinea thus inhabit the arctic region of this 

 continent, including Greenland. But while the former extends eastward through 

 arctic Europe to Ural, the latter extends westward through Siberia to the river 

 Olenek (Long. 120° E.). With regard to their southern distribution, T. palustris 

 does not extend beyond Minnesota on this continent, while in Europe it reaches 

 the Alps of Switzerland; T. coccinea does not extend beyond Canada, while in 

 Asia it extends to the Baikal mountains. While thus the southern distribution 

 of these species corresponds well with the northern as far as concerns Europe 

 and Asia, their absence from the central Rocky mountains seems strange. 

 Furthermore, with regard to the third species, T. calyculata, its occurrence in 

 South Europe and Kamtchatka is difficult to combine. 



We have thus in the genus Tofieldia two decidedly northern species, both 

 represented in Greenland and on this continent, and a southern, T. calyculata, 

 which in the Alps of Switzerland is, to some extent, accompanied by the northern 

 T. palustris. No doubt the present distribution points toward the north as 

 being the geographical centre of T. palustris and T. coccinea, but it seems impos- 

 sible to decide whether the centre was located on the American continent or in 

 Greenland. 



Lloydia serotina was collected on the arctic coast; it occurs also in arctic 

 Russia, Nova Zembla, and arctic Siberia, from Jalmal, Long. 70° 30' E., to 

 Pitlekaj, Long. 173° 24' W. Farther south it is widely distributed in the Alps 

 and Pyrenees, Caucasus, Altai mountains, the Himalayas, besides in our Rocky 

 mountains, as far south as Colorado. Being absent from the arctic American 

 archipelago, from Greenland and Scandinavia, I/Zoi/dm cannot be considered a 

 circumpolar species, and the very extensive distribution in the mountains 

 farther south may indicate a southern location of its centre, however, not on this 

 continent. The occurrence of the plant on both coasts of Bering strait seems to 

 indicate the road, followed from Siberia to the north of America, and from there 

 to the Rocky mountains. The location of the original centre is difficult to 

 decide, and it seems plausible to suppose that the species developed from two 

 centres, one in the European Alps, another in the Himalayas. 



Of the genus Salix eleven species were collected on the arctic coast by the 

 expedition, but to these I have added S. alaxensis, which was found at King 

 point by the Gjoa expedition; furthermore, I have added S. polaris Wahlenb., 

 accordmg to Simmons (I.e. p. 73), who states that a specimen collected by Miert- 

 sching at Cape Bathurst represents this species. 



Three of these willows are circumpolar, viz. : Salix glauca, S. polaris, and 

 S. reticulata; the absence from arctic Russia makes S. arctica non-circumpolar; 

 with regard to S. ovalifolia and S. rotundifolia, these species are not only absent 

 from Russia, but also from Greenland and the arctic American archipelago. 



S. Richardsonii and S. alaxensis have been recorded from the arctic archi- 

 pelago, besides from the American coast of Bering strait; but S. phlebophylla, S. 

 pulchra, and S. niphoclada are known only from the arctic coast, explored by 

 the expedition, and from the American coast of Bering strait. Finally, S. 



