Leguminosae. 



Phyllodia falcate, coriaceous, 10 to 15 cm long, varying from 6 to 8 mm to 24 mm or 

 more in breadth, narrowed at the base, acute or obtuse at the tapering apex; the smooth 

 surface is striate with many nerves; on younger plants the phyllodia bear a bipiniiate 

 leaf; the leaflets 12 to 15 pairs, oblong, emarginate, crowded; peduncles solitary or fascicled 

 in the axils, about 12 mm long, bearing a dense many flowered head of 8 mm in diameter, 

 calyx teeth very short 5 in number, petals 5, oblong lanceolate, glabrous, more or less 

 united, longer than the calyx, half the length of the stamens; legume broadly linear, 

 straight or slightly falcate, 7.5 to 15 cm long, 16 to 18 mm broad, glabrous, flat, two- 

 valved, about 12 seeded; seeds dark brown to black. 



The Koa is one of our most stately forest trees and is next to the 07? la lehua 

 (Metrosideros polymorplia), the most common. It is perhaps the most valuable 

 tree which the islands possess, as it is adapted for construction as well as for 

 cabinet work. The Koa reaches a height of more than 80 feet in certain locali- 

 ties, with a large trunk vested in a rough, scaly bark of nearly an inch in 

 thickness. When growing in the open, it develops a beautiful, symmetrical 

 crown, with usually short trunks of perhaps 15 to 20 feet in height and a di- 

 ameter of more than 6 feet. The lower branches are then almost horizontal, 

 far-spreading, while farther up the branches become peculiarly twisted and 

 more or less ascending. When growing in the rain or fern forest, it develops a 

 long, straight bole of considerable length and thickness, clothed in a rather 

 smooth, gray bark ; usually branching 40 feet or so above the ground. ( See plate 

 68.) It is this sort of timber which is most valuable for construction work, 

 while the Koa of the drier districts has a much more beautiful wood and is 

 more suitable for cabinet work. The Koa has two kinds of leaves, true leaves 

 and phyllodia. Young twigs or young trees always have first the true twice 

 pinnate leaves, which gradually pass into phyllodia that is, the petioles become 

 dilated and take the place of the true leaf. 



The adult trees bear phyllodia only, though an occasional twig near the base 

 of the trunk will have true leaves. The Koa is found on all the islands of the 

 group, and adapts itself to almost any condition. It descends to as low as 600 

 feet, and ascends to an elevation of 5000 feet, and sometimes higher. Beautiful 

 trees can be observed on the slopes of Mauna Loa on the Island of Hawaii, not 

 far from the volcano, as well as in South Kona on the same mountain. It is 

 sad, however, to see these gigantic trees succumb to the ravages of cattle and 

 insects. 



Large tracts of Koa forest which twenty years or so ago were in their prime 

 have now perished, and nothing is left but the dead trunks with their huge 

 branches dangling on strings of bark, ready to drop from the dizzy heights, 

 when stirred by the slightest gust of wind, crushing everything beneath them. 

 Such is the condition of the Koa forest of today in certain tracts of land on 

 Hawaii. Cattle are the great enemy of the Koa. 



Above Kealakekua, in South Kona, of the once beautiful Koa forest 90 per 

 cent of the trees are now dead, and the remaining 10 per cent in a dying con- 

 dition. Their huge trunks and limbs cover the ground so thickly that it is diffi- 

 cult to ride through the forest, if such it can be called. It might be said, how- 



175 



