ler and most woody islands in the westerly portion of the
group, especially in Kauai and Oahu, that the greatest number and variety
of plants are found and the largest proportion of peculiar species and
genera. These are believed to form the oldest portion of the group, the
volcanic activity having ceased and allowed a luxuriant vegetation more
completely to cover the islands, while in the larger and much newer islands
of Hawaii and Maui the surface is more barren and the vegetation
comparatively monotonous. Thus while twelve of the arborescent Lobeliaceae
have been found on Hawaii no less than seventeen occur on the much smaller
Oahu, which has even a genus of these plants confined to it.

It is interesting to note that while the non-peculiar genera of flowering
plants have little more than two species to a genus, the endemic genera
average six and three-quarter species to a genus. These may be considered
to represent the earliest immigrants which became firmly established in the
comparatively unoccupied islands, and have gradually become modified into
such complete harmony with their new conditions that they have developed
into many diverging forms adapting them to different _habitats_. The
following is a list of the peculiar genera with the number of species in
each. {327}

_Peculiar Hawaiian Genera of Flowering Plants._

Genus. No. of Species. Natural Order.

1. Isodendrion 3 Violaceae.
2. Schiedea (seeds rugose or muricate) 17 Caryophyllaceae.
3. Alsinidendron 1 ,,
4. Pelea 20 Rutaceae.
5. Platydesma 4 ,,
6. Mahoe 1 Sapindaceae.
7. Broussaisia 2 Saxifragaceae.
8. Hildebrandia 1 Begoniaceae.
9. Cheirodendron (fleshy fruit) 2 Araliaceae.
10. Pterotropia (succulent) 3 ,,
11. Triplasandra (drupe) 4 ,,
12. Kadua (small, flat, winged seeds) 16 Rubiaceae.
13. Gouldia (berry) 5 ,,
14. Bobea (drupe) 5 ,,
15. Straussia (drupe) 5 ,,
16. Remya 2 Compositae.
17. Tetramolob