574 
Sinnott and Bailey . — The Origin and 
B. The Hawaian Islands . 
The Hawaian Islands, isolated so completely in the middle of the 
Pacific Ocean, support a fauna and flora which are recognized by biologists 
to be very ancient. The flora is particularly rich for an oceanic island and 
consists of 718 species of Angiosperms, of which 574 are endemic, or 80 per 
cent. There are 265 genera, and of these 36 are endemic, or 13 per cent. 
Such a high degree of endemism seems clearly to imply great antiquity. 
An analysis of the dicotyledonous flora with regard to the relative pro- 
portions of herbs and woody plants is presented in the following table : 
Indigenous species 
Non-endemic species 
Endemic species of non-endemic,.genera . 
Species of the endemic genera . . . 
Total Species. 
Herbs. 
% Herbs. 
582 
138 
24 
82 
62 
76 
257 
55 
21 
243 
21 
8.5 
It will be observed that the species of the endemic genera, that element 
of the flora which is presumably the most ancient of all, if endemism is 
a true criterion of antiquity, is overwhelmingly woody ; that the next 
younger element, the endemic species of non-endemic genera, has a con- 
siderably higher percentage of herbaceous forms, and that the youngest 
element, composed of the non-endemic species, is preponderantly herbaceous. 
This ancient flora contains many curious plants. Families and genera 
which in most other parts of the world are entirely or mainly herbaceous 
are represented here by woody forms. Wallace ( 14 , p, 328) remarks that 
‘ Among the curious features of the Hawaian flora is the extraordinary 
development of what are usually herbaceous plants into shrubs or trees. 
Three species of Viola are shrubs from three to five feet high. A shrubby 
Silene is nearly as tall ; and an allied endemic genus, Schiedea , has 
numerous shrubby species. Geranium arboreum is sometimes twelve feet 
high. The endemic Compositae are mostly shrubs, while several are trees 
reaching twenty or thirty feet in height. The numerous Lobeliaceae, all 
endemic, are mostly shrubs or trees, often resembling Palms or Yuccas 
in habit, and sometimes twenty-five or thirty feet high. The only native 
genus of Primulaceae — Lysimachia — consists mainly of shrubs ; and even 
a plantain has a woody stem sometimes six feet high.’ 
Guppy ( 7 ), who has made a special study of the floras of the Pacific, 
regards the Compositae with 8 endemic genera, and the Lobeliaceae 
with 5, as the most ancient portion of the Hawaian flora, since they are 
strikingly developed here but have almost no near allies elsewhere in 
the Pacific, a circumstance which he attributes to their establishment 
on Hawaii during the latter part of the Tertiary when most other Pacific 
islands were submerged. Of these families the 13 genera, comprising 98 
species, are entirely woody save one, Lipochaeta , which includes 5 species 
that are essentially herbaceous. 
