262 Plant Life and Evolution 



gum," of Eastern America, also occur, and one of 

 the showiest of the smaller trees, Gordonia, with 

 big white flowers like Cherokee roses, belongs to 

 the same genus as the loblolly bay of the Gulf States. 

 The northern aspect of the vegetation increases 

 rapidly as the summit of the mountain is ap- 

 proached. The low, gnarled trees composing the 

 forest are bearded with gray lichens, like those of 

 the northern forests, but from these same trees hang 

 beautiful orchids, not at all reminiscent of the 

 North, and the stately tree-ferns, as well as many 

 other plants unfamiliar to the northern botanist, 

 remind him that he is still in the tropics, in spite 

 of the cold gray skies. At this altitude a number 

 of showy small trees and shrubs of northern origin 

 are common. Huckleberries, wintergreen (Gaul- 

 theria), and fine orange and scarlet rhododendrons 

 are common. Thickets of brambles, and carpets of 

 everlastings (Gnaphalium), buttercups, violets, bal- 

 sams, and other familiar flowers abound, and in 

 the sheltered thickets among the bushes are colonies 

 of a stately primrose, Primula imperialis, which for 

 many years was known only from this mountain. 

 Many of these plants, like the primrose, have their 

 nearest relatives in the Himalayas, and it has been 

 suggested that the seeds of some of them may have 

 been carried by the strong, prevailing winds of the 

 upper atmosphere, which blow southeastward for 

 long periods. This, however, seems hardly probable 

 in the case of many of the species, whose presence 



