290 A NATURALIST IN THE PACIFIC chap. 



this sense only that the term " mountain-genera " is used in 

 relation with this group. 



Moiintaiii-Genera of the Tahitiati or East Polynesian Region. 



Weinmannia, Saxifragaceae, from New Zealand. 

 Coprosma, Rubiacese, from New Zealand. all species 



Vaccinium, Vacciniaceae, from the northern hemisphere, j endemic. 

 Astelia, Liliacese, from New Zealand. 



Coriaria, Coriariaceae, from New Zealand 1 



Cyathodes, Epacridace^e, from New Zealand . . . . | " , 



) endemic. 



Nertera depressa, Rubiaceee, a species of the Antarctic flora. 



Luzula campestris, Juncaceae, from die northern hemisphere. 



The Tahitian non-endemic mountain-genera, though scanty in 

 number, are of considerable interest to the student of plant- 

 dispersal. Among those possessing only species that are confined 

 to Eastern Polynesia, genera that would be regarded as belonging 

 to a past era of dispersal, Weinmannia, Coprosma, Vaccinium, and 

 Astelia may be mentioned. 



Weinmannia, a Saxifragaceous genus of trees and shrubs, not 

 represented in Hawaii, but recorded from almost all the elevated 

 oceanic groups of the tropical South Pacific, as well as from the 

 New Hebrides and New Caledonia, has its home in South 

 America, more particularly in the Andes, and also occurs in New 

 Zealand, Tasmania, and the Mascarene Islands. One can scarcely 

 doubt that, as in the case of Coprosma, the Pacific Islands 

 derived their species originally from high southern latitudes, as 

 from New Zealand, the absence of the genus from Hawaii 

 negativing an American origin. Of the two Tahitian species, one 

 is peculiar to Tahiti, whilst the other, W. parviflora, which is 

 conspicuous on the mountain-crests at elevations of 3,000 feet and 

 over, occurs also in the Marquesas. Another species grov/s in 

 abundance in the interior of Rarotonga. Samoa possesses two 

 species, one of which, W. affinis, occurs in Fiji, and the other, 

 W. samoensis, which frequents the mountains at elevations of 

 1,500 to 3,300 feet, is seemingly endemic. Fiji possesses four or 

 five species of Weinmannia occurring at all altitudes up to 2,000 

 feet, of which some are evidently peculiar. The capsular fruits of this 

 genus contain hairy seeds that would probably become entangled 

 in a bird's plumage. Dispersal by birds is distinctedly indicated 



