9 



The fifth group is of entirelj- problematical relationship. With the 

 exception of C. deschanq)sioif1es, which ranges from the Pribilof Islands 

 to Kamchatka, and is therefore more Asiatic than American, the spe- 

 cies are endemic and are found only in the mountains of California. 



hreiveri — lemmoni dvschanqysioides bolanderi. 



Finally, C. cinnoides stauds alone, an extremely isolated type without 

 near relations. 



GEOGRAPHICAL DISTRIBUTION. 



The genus Calamagyosfis contains approximately one hundred and 

 fifty species, widely distributed over the globe, but in such a manner as 

 to point strongly to a boreal origin, according to the generally accepted 

 theory of migration during the glacial epoch, for outside of cold 

 and cool temperate regions the species are found only on the higher 

 mountains. 



The development of numerous endemic forms in Australia and New 

 Zealand is at first sight an obstacle to this theory of the origin of the 

 genus, but the occurrence of scattered species on the mountains of 

 India and the Malaj'an region deprives that objection of its force. The 

 great number of species along the South American Cordilleras is per- 

 fectly in harmony with the known laws of plant distribution. The 

 genus is at present most strongly developed in northern Europe and 

 Siberia (twenty-five species), western North America (thirty-two spe- 

 cies), the Andes region (seventy species), and Australia, including New 

 Zealand and Tasmania (twenty species). There are eleven species in 

 Atlantic North America, fifteen in Mexico and Central America, fifteen 

 in the Himalayan-^Ialayan region, ten in eastern Asia, and fifteen in 

 central and western Asia. With the exception of about ten species of 

 the section Epigeos Koch, inhabiting the northern temperate regions of 

 the Old World, all belong to the section iJeyenxia, which is often 

 regarded as a separate genus, but is at best an artificial and unsatis- 

 factory one. 



Two of the tljirty-eight North American species (C. Jfoigsdorffii and 

 €. neglecta) occur also in northern Europe and Asia, two more {C. pur- 

 purascens and C. liyperborea) are found outside this continent onlj- in 

 Greenland, while a fifth (C. deschampsioidcs) is common to the Pribilof 

 Islands and northeastern Asia. The remaining species are believed to 

 be endemic. Considering the distribution of the genus in North America 

 from a purely geographical standpoint we find ten species in the 

 Atlantic-Ai^pahichian region. Of these, three extend into the S(mthern 

 States, one occurring in the undulating "middle" country and in the 

 foothills, the other two only upon the highest mountains (above 1,800 

 meters). The genus is not represented in Florida, Mississippi, Loui- 

 siana, Arkansas, the Indian Territory, and Texas. Some half dozen 

 species occur in the prairie districts and the region about the Great 



