DERIVATION OF THE FLORA OF HAWAII 17 



far north as Luzon, in the Philippines, and it is also known from South 

 Africa and Abyssinia. The largest number of species is found in New 

 Zealand, and the genus is not represented elsewhere in Polynesia. 



The cold bogs, such as occur on the plateau of Kauai, recall similar 

 bogs in the temperate parts of Europe and America. In addition to the 

 tussocks of grasses and sedges, one encounters such familiar types as 

 Vaccinium, Ranunculus, Viola, Geranium and even Drosera. 



While the American element in the Hawaiian flora is much less evi- 

 dent than that of the southern hemisphere, there are several forms whose 

 American relationships are unmistakable. The wild strawberry, Fragaria 

 chilensis, is identical with the American species. The genus Sisyryn- 

 chium, except for the solitary Hawaiian species, is confined to America, 

 and a number of the Compositae are undoubtedly related to Western 

 American genera. Most of the genera are peculiar to the islands, but 

 they are all evidently related to Western American ones. Thus Campy- 

 lotheca is related to Coreopsis and Bidens, the "silver sword" (Ar- 

 gyroxiphium) is related to the Calif ornian tar- weeds (Madieae), and the 

 Hawaiian Raillardia is close to the Californian Raillardella. 



A small number of other genera, e. g., Nama, Vallesia, are also 

 apparently of American origin. 



The most comprehensive attempt that has yet been made to explain 

 the origin and distribution of the Hawaiian flora is that of Guppy, 15 who 

 accepts the hypothesis that the archipelago has always been completely 

 isolated. His views as to the advent of the various elements of the flora 

 are exceedingly ingenious and suggestive, but his conclusions cannot 

 always be accepted without question. 



Guppy assumes that the Hawaiian Islands first emerged from the 

 ocean in early Tertiary times. This conclusion is based mainly upon 

 Hillebrand's 16 hypothesis that the absence of conifers in the islands is 

 due to the emergence of the latter subsequent to the period when conifers 

 were predominant. 



Following the studies of Treub on the restoration of the vegetation 

 on Krakatau, after the great eruption of 1883, Guppy assumes that the 

 establishment of vegetation on Hawaii followed the same course, and 

 that the succession of plants was the same in the Hawaiian Islands as on 

 Krakatau. 17 



That this conclusion is not entirely justified may safely be assumed. 



18 Guppy, H. B.: "Observations of a Naturalist in the Pacific," 2. London. 

 1906. 



16 Loc. cit., Introduction, p. xiii. 



17 Treub, M. : "Notices sur la nouvelle flore de Krakatau," Ann. du Jardin 

 Bot. de Buitenzorg, 7, 213-223. 1888. 



