lower forest region. In these restricted areas one may find from 40 to 50 

 species of trees, some of which are confined to one locality only. It is in these 

 places that the writer has found many new species of trees and rediscovered 

 some which were thought to have become extinct. Of course, most of the Ha- 

 waiian plant genera have representatives in both wet and dry districts, which 

 differ so greatly from each other that one cannot help coming to the conclusion 

 that they must have originated in different periods, meaning that their evolution 

 was not carried on simultaneously. 



The Kukui is sparingly represented in these floral districts and is replaced 

 by the araliaceous Reynoldsia sandwicensis, a striking tree of sometimes 50 feet 

 in height. (See plate VII.) It is one of the trees which possesses a soft wood 

 and an exceedingly thin bark. Its most plentiful associate is the leguminous 

 Erythrina monosperma, the Wiliwili of the natives, whose wood is also very 

 light and soft. 



Nearly all Hawaiian Araliaceae come into this region, with the exception of 

 a very few species, such as Tetraplasandra Waialealae, the Oahuan varieties of 

 T. meiandra, Clieirodendron platyphyllum, and Pterotropia gymnocarpa, which 

 are characteristic of the rain forest. Pterotropia dipyrena is peculiar to the 

 region discussed in this chapter, though sometimes going over into the middle 

 forest zone, to which Pterotropia Kavaiensis, a handsome tree found only on the 

 island of Kauai, is peculiar. 



The Apocynaceae have three arborescent species represented, Rauwolfia sand- 

 wicensis (Hao), either a shrub or more often a tree, and Ochrosia sandwicensis 

 (Holei), not uncommon, and Pteralyxia macrocarpa (Kaulu), only found on 

 Oahu in the valley of Makaleha. The latter is a small tree, with large, bright 

 red, double fruits. The Gynopogon oliviformis (Maile), also belonging to this 

 family, has a variety myrtillifolia occuring in the dry forests, usually climbing 

 over trees, and sometimes strangling them to death. 



The most common tree is the liliaceous Dracaena aurea, or Halapepe of the 

 natives. It is entirely restricted to this region and only very rarely is found 

 outside of it. 



These dry or mixed forest regions occur, however, in other tropical countries, 

 as in East Java and India, and are peculiar in so far as they are composed of 

 periodically deciduous trees. In Hawaii only three or four species lose their 

 leaves in the dry season, as Erythrina monosperma, Reynoldsia sandwicensis, 

 Kokia drynariodes, and Sapindus saponaria. The same may be said of No- 

 thocestrum, which also sheds its leaves, but without ever becoming leafless, as 

 its defoliation immediately precedes its acquisition of new foliage. These dry, 

 forest regions or mixed woodlands have hardly ever been investigated, previous 

 explorers confining their investigations to the wet forests, which appear from a 

 distance much more promising. These rain forests, however, display much less 

 variety than the mixed forest, where not a single tree species can be called domi- 

 nant. Of course, there are exceptions, as for example in South Kona, on Hawaii, 



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