104 B Canadian Arctic Expedition, 1913-18 



S. Hirculus originated in the arctic regions. For nowhere where the species 

 occurs does it exhibit any pronounced tendency to vary, except with regard to 

 the foliage: "oblongo-lanceolata," "linearia," "spathulata," etc. By some 

 authors, Lange, for instance (Consp. Fl. Groenl.), the arctic plant is considered 

 as representing a variety "alpina Engl." from the Himalayas, but the deviation 

 from the type depends merely upon a dwarfed, more condensed growth, the 

 leaves a little broader, etc. The arctic plant resembles the alpine; it is able to 

 produce flowers and ripen the seed even as far north as Spitzbergen, according 

 to Hesselman (I.e.), although probably not every year. 



With respect to S. rivularis and S. cernua, both being also widely distributed 

 farther south, especially the latter, these species are well adapted to the arctic 

 climate, by developing bulblets which, in the latter, have almost entirely re- 

 placed the flowers; in this respect S. cernua resembles the arctic form of S. 

 stellaris, as described. The geographical centre has undoubtedly been within 

 the arctic regions. The prevalence in the north, together with the circum- 

 polar distribution, seems to indicate that S. nivalis and S. hieraciifolia are also 

 arctic types and that they originated in the polar regions. 



But with regard to S. decipiens, it seems somewhat doubtful whether an 

 arctic centre could be credited to this species. We should remember that the 

 section Dactyloides is decidedly southern, and S. decipiens is, so far as we know, 

 about the only one which occurs in the polar regions and is circumpolar. It 

 has, however, two near allies, the distribution of which reaches far north, namely, 

 S. hypnoides L., which is common in Iceland but more widely distributed in 

 southwestern Europe, and /S. silenaefloraStemh., known only from arctic and sub- 

 arctic North America, viz. : Hudson bay region and Alaska. 



As far as concerns S. decipiens, this polymorphic species is best developed 

 in the mountains of Central Europe, but is totally absent from the Asiatic 

 mountains. Engler (1. c.p. 186) has enumerated several varieties, among which 

 "groenlandica" is credited to the arctic regions, and also to Norway, Iceland, and 

 Great Britain; two other varieties, "caespitosa" and "uniflora," are also credited 

 to the northern regions. But the more evolute forms "vulgaris" and "quinque- 

 fida" are exclusively southern. It would thus appear as if the species had 

 developed in the south, Central Europe for instance, where it is best represented 

 and best developed. Wherever it is met with in the polar regions it is always of 

 a stunted growth and few-flowered, which might indicate that it is a foreigner 

 in these regions, but having adapted itself remarkably to the change of condi- 

 tions, and having acquired such wide distribution so as to become circumpolar. 



Otherwise with regard to S. oppositifolia. This species being circumpolar 

 and so well adapted to the arctic climate may, in spite of the enormously wide 

 distribution farther south, be considered as a truly arctic type. The other 

 members of the section Porphyrion occur only in the highest mountains of Central 

 Europe, but one of these, S. biflora All., has also become distributed as far north 

 as arctic Russia. 



From a geographical point of view the genus Dryas is very interesting, and 

 in some respects quite remarkable. D. octopetala and D. integrifolia were both 

 collected by the expedition, while the more southern species D. Drummondii 

 Hook, was not met with. 



As may be seen from Table 1, D. octopetala is not only circumpolar but is 

 also widely distributed farther south, notably in Iceland, Scandinavia, the Alps 

 and Pyrenees, Caucasus, Altai and Baikal mountains, the Rocky mountains 

 south to Colorado, and the Asiatic coast of Bering strait, viz. : St. Lawrence and 

 Konyam bay. D. integrifolia, on the other hand, is in the arctic region confined 

 to the shore explored by the expedition, the American archipelago, Greenland, 

 and the coasts of Bering strait. In Canada D. integrifolia has been recorded 

 from Island of Anticosti, Labrador, the coasts of Hudson bay, extending 

 westward to Bering strait; its southern limit in the Rocky mountains is: Summit 

 of Moose mountain, Elbow river, at an elevation of 7,500 feet. 



