Leguminosae. 
Phyllodia faleate, coriaceous, 10 to 15 em long, varying from 6 to 8 mm to 24 mm or 
inore in breadt : narrowed at the base, cabs or obtuse at the tapering apex; the smooth 
ace is striate with many nerves; on younger ree the phyllodia bear a bipinnate 
lat the lea rye 12 to 15 pairs, yen em gripes ed; peduncles solitary or fascicled 
n the axils, about 12 mm long, bearing a a dens pis mowacel head of 8 mm in diameter, 
aoa teeth very short 5 in Tunber, petals 5, oblong lanceolate, glabrous, more or less 
united, longer than the ioreaciy half the mele of the stamens; legume broadly linear, 
valved, about 12 seeded; seeds dark brown to black 
The Koa is one of our most stately forest trees and is next to the Ohia lehua 
(Metrosideros polymorpha), 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 voleano, 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 
