126 B Canadian Arctic Expedition, 1913-18 



contains the most important centres of the species of this genus. We might 

 quote from DeCandolle's excellent monograph ^ the data as follow : Spanish 

 Peninsula: 18 species, 6 endemic. Italy and Dalmatia: 36 species, 11 endemic. 

 Greece and Asia Minor: 36 species, 24 endemic. France, Corsica and Sardmia: 

 13 species, none endemic. 



With regard to Siberia, 11 species are known from Ural, 10 from Altai, and 

 7 from Baikal. Nevertheless, the number of arctic species is extremely small, 

 viz.: C. uniflora L., C. lasiocarpa DC, C. rotundifolia L., var. arctica Lge., and 

 C. groenlandica Berlin ;2 and strange to say, C. uniflora is absent from Russia and 

 Siberia with the only exception of Konyam bay where Kjellman found it. Nova 

 Zembla, and Arakamtschetschene island (C. Wright). 



Still the species occurs in Scandinavia, Spitzbergen, Greenland, the north 

 coast of this continent, including the archipelago, besides from Labrador to Alaska, 

 and south to the Colorado Rocky mountains. 



By the structure of the flower and the capsule, besides by the habit, C. uniflora 

 appears to be an ally of C. cenisia L., a native of the alpine regions of the Alps. 

 But it shows no immediate affinity with C. lasiocarpa Cham, except "capsula 

 lateraliter versus apicem dehiscente." DeCandoUe regards C. lasiocarpa as an 

 ally of some Siberian species, notably C. Adami Bieb. and C. dasyantha Bieb., 

 but it differs from these, however, by the sinuses of the calyx being only minutely 

 appendiculate; C. lasiocarpa is a native of the alpine summits of the high-northern 

 Rocky mountains and of the northwest coast and islands; C. dasyantha (C. 

 pilosa Pall.) inhabits Alaska and the Aleutian islands, Kamtchatka and eastern 

 Siberia; C. Adami, on the other hand, is a native of Caucasus. 



We have thus in these species of Campanula, represented in the arctic 

 regions, a. commingling of types among which C. uniflora occupies a somewhat 

 isolated position; considering the wide distribution on this continent where it is 

 either arctic or alpine, it seems probable that C. uniflora is a member of the old 

 glacial vegetation, and that the centre of its distribution was located in the 

 arctic regions of this continent. The occurrence of this species in Scandinavia 

 is one of the several cases which Nathorst has mentioned as demonstrating the 

 probable road of migration of the American element across Greenland to Iceland 

 and Scandinavia. With regard to Campanula rotundifolia, this is not an arctic 

 type, judging from its predominant distribution southward, but the species 

 is evidently one of those that accompanied the arctic flora on its retreat to the 

 north. But in the arctic regions C. rotundifolia has developed a type, "C. 

 groenlandica Berl.," which together with the variety arctica Lge. thus represents 

 the species in the far north. 



As regards C. lasiocarpa on the northwest coast, this is undoubtedly of 

 Siberian origin, as indicated by DeCandolle, and the same is the case of C. 

 dasyantha. The analogy in floral structure, through which these appear to be 

 related to the Caucasian C. Adami, is one of the many instances of analogous 

 structures being possessed by plants at stations ever so remote and resulting, 

 sometimes I believe, in the development of identically the same species. 



If we finally consider the Compositae, a score of species is all that the expedi- 

 tion brought home from the north coast, and nowhere in the arctic is this family 

 much in evidence in proportion to its size, some 12,000 species having been 

 described. From arctic Russia and arctic Siberia we have only record of about 

 50 species according to Ledebour (I.e.), while from the small area of arctic Scan- 

 dinavia Hartman (I.e.) has enumerated about SO species, 18 of which are Hierada; 

 in Greenland the family is represented by about 30 species 10 of which are intro- 

 duced weeds, principally at the colony Ivigtut. 



' Alphonse DeCandolle: Monographie des Campanulinfeea. Paris, 1830. 



2 Karlvaxter, insamlade under den Svenska Expedltionen till Gronland 1883, I.e. p. 50. 



