100 B Canadian Arctic Expedition, 191S-18 



30', Dus6n), but which has not been found, so far, on the North American coa,st. 

 With regard to the arctic Siberian element, Kjellman (I.e.) has recorded nine 

 species from the north coast, principally collected by himself on the Vega 

 expedition. These species are: R. Chamissonis Schl., R. Pallasii, R. sulphureus, 

 R. nivalis, R. pygmaeus, R. hyperboreus, R. affinis, R. acris, and R. lapponicus. 

 Concerning the arctic American element, this consists of six species, namely: 

 R. Purshii Richards., R. Cymbalaria FuTsh, R. Sabinii R. Br., R. occidentalis 

 Nutt., R. lapponicus L., and to some extent, R. affinis R. Br. 



Ranunculus occidentalis Nutt., a near ally of R. recurvatus Poir., is a native 

 of open woods and low ground in the northern Rocky mountains, from where it 

 extends to the Alaskan coast and islands, and south to the borders of California. 

 The variety robustus Gray has been collected on the Alaskan islands, and on the 

 north coast. 



With regard to the representation of the genus throughout the northern 

 hemisphere, the Old World element is quite distinct from the North American. 

 On this continent 53 species are enumerated in the Synoptical Flora, not includ- 

 ing 6 introduced species, and not either the genera Kumlienia, Arcteranthis, 

 Cyrtorhyncha, and Batrachium. And among these species of Ranunculus some 

 certain groups are much better represented on this continent than in Europe 

 and Asia. For instance, the section comprising R. ambigens Wats., which 

 corresponds to the Eurasian it!. Flammula alliance; furthermore, the sections of 

 R. adoneus Gr., and of R. abortivus L., which do not seem to have any analogous 

 representations in the Old World. On the other hand, the section comprising 

 R. hispidus Michx. is well exemplified in the Old World, and more extensively 

 so than oH this continent. The circumpolar species: R. hyperboreus, R. pygmaeus, 

 R. nivalis, and R. lapponicus, besides R. Pallasii, R. sulphureus, R. Sabinii, and 

 M. affinis are, as may be seen from Table 1, much more widely distributed in 

 4he polar regions than farther south; some few have extended as far south as 

 ■the Altai mountains, and some even to the Himalayas. But their principal 

 Tange lies within the arctic region where they undoubtedly originated. R. 

 ^Cymbalaria does not properly belong to the arctic region, even though it has 

 reached the west coast of Greenland at a very few stations only; the distribution 

 of this species is mainly "sea-shore and margins of salt-ponds in the prairie 

 region of this continent;" however, it has also been recorded from several stations 

 in the Hudson bay region, and even farther north. 



While thus the arctic species, with the only exception of R. Sabinii, have 

 also been recorded from the Old World, it seems somewhat strange that the 

 American alpine element of the genus is not represented; and the same is the 

 case of the Eurasian alpine element, for the few species enumerated above as 

 having found their way to the arctic region, R. auricomus, R. repens, etc., 

 are lowland types, and the extension of their southern range northward is 

 evidently of a relatively recent date. 



The circumpolar Papaver nudicaule is a genuine arctic type which during 

 the glacial epoch became widely distributed in the higher mountains farther 

 south; and although still in existence in the Altai mountains, Dovre mountain 

 in Norway, and in the Rocky mountains as far south as Colorado, there is no 

 trace of the species in the Alps or Pyrenees. It is one of the three plants which 

 have been found north of Lat. 8Z° ,Saxifraga oppositifolia and Alopecurus alpinus 

 being the two others; it may also be mentioned that Papaver nudicaule occurs in 

 western Thibet at an elevation of 16-17,000 feet. 



Among the Cruciferae we meet with types of very distinct geographical 

 distribution: 



I. Circumpolar: Draba alpina, D. nivalis, D. fladnizensis, and D. hirta; 

 Eutrema, and Cardamine pratensis. 



II. Arctic, but not circumpolar: Lesquerella, Cochlearia, Draba corymbosa, 

 Braya, Hesperis, Cardamine digitata, and Parrya. 



