Leguminosae. 



ever, that there are still tracts of land where the Koa forest is in its natural 

 condition. As already mentioned, the Koa adapts itself to almost any 

 environment. Ancient aa (rough) lava flows have been covered by Koa trees 

 to the exclusion of everything else. It is on these lava fields that the trees are 

 still in good condition, as cattle usually avoid crossing these sharp, rugged fields 

 of lava. 



From the big trees found in Kona, Hawaii, the natives of by-gone days used 

 to carve their great war canoes. Occasionally one can find an unfinished log 

 which, owing to its enormous weight, was abandoned by the natives, who were 

 unable to remove it to the lowlands and beach. Today the wood is used for 

 furniture and is sold as Hawaiian mahogany, though, of course, it bears no 

 relation to the tree of that name. The bark of the Koa was used by natives 

 for tanning purposes. 



At lower elevations, as on Oahu on the windward side, Koa is associated 

 with the screw pine (Pandanus odoratissimus), while at the middle forest zone, 

 at 4000 feet, it is usually found in company with the Naio (Myoporum sand- 

 wicense), Kolea (Suttonia), Metrosideros polymorpha, and Mamani (Sophora 

 chrysophylla), while in the forks of its branches in accumulated humus flourish 

 arborescent species of Lobelias of the genus Clermontia. 



The Koa is peculiar to the Hawaiian Islands, but is closely related to a 

 species {Acacia heterophylla Willd.), in Mauritius and Bourbon; while Acacia 

 laurifolia is a seaside tree in Viti and Samoa; the vernacular name in Viti is 

 Tatakia, and in Samoa Tatakia or Taiagia. 



The Koa is attacked by several insects. A few lepidopterous insects feed on 

 the Koa leaves, such as Scotorythra caryopis Meyr and 8. idolias Meyr, which 

 are often responsible for the defoliated Koa trees, as well as the S. rara (Bult.), 

 the most common species of the genus. Of borers, several beetles live in the 

 Koa trunks, such as Aegosomus, while the larvae of Thyrocopa alboonu- 

 bila Walsm. are found in dead branches of Koa, as well as larvae of T. abusa 

 Walsm. on the bark and dead twigs. Besides, other lepidopterous insects may 

 be found in more or less decayed Koa trunks. 



Acacia Koaia Hbd. 

 Koaia or Koa oha. 



ACACIA KOAIA Hbd. Fl. Haw. Isl. (1888) 113;— Del Oast. 111. PI. Ins. Mar. Pacif. VI 

 (1890) 160. 

 Leaves as in Koa; axillary racemes with not more than 3 heads, generally reduced 

 to a single one; pod very narrow, not over 8 mm wide, and about 15.5 to 15 cm long; 

 otherwise as in Acacia Koa. 



The Koaia, unlike the Koa, is a rather small tree, reaching a height of only 

 20 to 25 feet. The trunk is not straight as in the Koa, but gnarled and twisted. 

 The bark is rough and corrugated. It differs mainly from the Koa in its pods, 

 which are very narrow, linear, while those of the Koa are broad. The leaves 

 are the same as in the Koa. 



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