XXII OTHER HAWAIIAN ENDEMIC GENERA 261 



The Hawaiian Endemic Genera excepting those of the 

 Composite and Lobeliace^. 



It will not be possible for me to do more than point out a few 

 o-eneral indications that can legitimately be drawn from these 

 genera. The subject bristles with difficulties for the systematist ; 

 but on one point there can be but little danger of going astray, 

 namely, in imputing to them a high antiquity in the floral history 

 of Hawaii. This can be said of all of them, whether or not the 

 generic distinction adopted in Dr. Hillebrand's work is always 

 adopted by botanists. It is therefore in this general sense that 

 they may be regarded as belonging to the early age of the 

 Hawaiian flora. 



Although the genera of Compositse and Lobeliaceas are pro- 

 minent amongst the representatives of the original flora of the 

 Hawaiian Islands, forming about two-fifths of the whole, the 

 genera of other orders are by no means inconspicuous, and their 

 variety is shown in the fact that though twenty-three in number 

 they belong to twelve orders. It is possible to divide these genera 

 into two groups — one the older and perhaps more or less con- 

 temporaneous with the Lobeliaceae and Compositae, the affinities 

 when apparent being American ; the other the more recent and 

 marking the close of the first era of the plant-stocking of these 

 islands, the affinities being all with the Old World, and especially 

 with Malaysia. This grouping is indicated in the list subjoined ; 

 and it may be here remarked that whilst shrubs, undershrubs, and 

 perennial herbs of the Caryophyllaceee, Labiatae, and Urticacese 

 form the features of the earlier group, trees of the Rubiaceae and 

 Araliacese are the most conspicuous members of the later group. 

 At the close of the earliest era known to us of the floral history of 

 the Hawaiian Islands we observe the commencement of those 

 forests that now throughout Polynesia as well as in Hawaii betray 

 their Asiatic origin. 



In making this distinction I am proceeding on the assumption 

 that the stream of migration, at first chiefly American in its source, 

 came ultimately in the main from the Asiatic side of the Pacific- 

 The change commenced, as I hold, in the latter portion of the first 

 era of plant-stocking, an era characterised by the arrival of those 

 early plants that are now represented by the endemic genera of 

 the archipelago. The genera of this early period that belong 

 neither to the Compositae nor to the Lobeliaceae are, as above 

 observed, arranged by me in two groups, one regarded as 



