culty. It is often dangerous to cross places where this fern grows, as it com- 

 pletely hides the ground underneath, sometimes concealing the holes, into which 

 one is likely to fall should he entrust himself to this treacherous fern. Several 

 species of Poly-podium are present, as P. spectrum, etc. Dryopteris and As- 

 plenium have also species in this locality. In the more open places the ground 

 is usually covered with Commelina nudiflora (Honohonowai) and several grasses, 

 with a few cyperaceous plants, such as Rhynchospora thyrsoidea and Galmia 

 Beecheyi. In the more open glades on the outskirts of the lower forests Micro- 

 lepia strigosa and Odontosoria ckinensis, the Palapalae and Palaa ferns, are 

 quite common, while occasionally Cibotium and Sadleria occur in this region also. 

 The family Flacourtiaceae is represented by two species in these islands, 

 both of the lower forest zone, though one, Xylosma Hawaiiensis, is peculiar to 

 the wet, the other, X. Hillebrandii, to the dry. This holds good of the euphor- 

 biaceous genus Antidesma, with its two species, A. platypkyllum and A. pulvi- 

 natum, the former occurring in the wet section as well as in the dry, while the 

 latter is found mainly in the dry section of the lower forest zone. 



SUBSECTION B LEEWARD LOWER FOREST FLORA. 



No two forest floras could be more different and strikingly peculiar than 

 those in question. The plant covering of the leeward regions, as for example 

 the Waianae mountains, Oahu, the southern slope of Haleakala, Maui, the 

 west end of Molokai, etc., is the richest in species as far as tree growth is con- 

 cerned. Nearly all trees growing on these more or less arid lava fields have 

 developed extremely hard, close-grained wood. Only four or five species, as 

 Reynoldsia, Erythrina, Nothocestrum, etc., are soft-wooded, and possess exceed- 

 ingly thin bark, while those of hard wood possess a usually rough, scaly bark of 

 perhaps half an inch or more in thickness. This striking flora gives the region 

 a most peculiar aspect, and more so in such places which were disturbed by more 

 or less recent lava flows, destroying the original vegetation, which is then suc- 

 ceeded by an entirely different plant growth. These districts which harbor such 

 an interesting flora are not very large, being only perhaps two to four miles 

 long at the most and much less wide. It is in these peculiar regions that the 

 botanical collector will find more in one day collecting than in a week or two in a 

 wet region, and may it be said here that it is indeed astonishing that these various 

 places like Puuwaawaa, North Kona, Hawaii, and Kahikinui, Maui, have been 

 entirely neglected by the botanical collectors who have previously visited these 

 islands. It may be of interest to know that not less than 60 per cent of all the 

 species of indigenous trees growing in these islands can be found and are pecu- 

 liar to the dry regions or lava fields of the lower forest zone, which in certain 

 localities gradually passes into the middle forest region, carrying a few trees up 

 into the latter zone. 



Exceptions are certain kipukas on Hawaii, at an elevation of between 4000 

 and 5000 feet, which possess a flora which is otherwise entirely restricted to the 



15 



