Acacia koa for up to 25 years. Scarification is needed before "A. koa" seeds will germinate. Koa is endemic to the islands of Hawaii, Molokai, Maui, Lānai, Oahu, and Kauai, where it grows at elevations of . It requires of annual rainfall. Acidic to neutral soils (pH of 4-7.4) that are either an Inceptisol derived from volcanic ash or a well-drained histosol are preferred. Its ability to fix nitrogen allows it to grow in very young volcanic soils. Koa and ōhia lehua ("Metrosideros polymorpha") dominate the canopy of mixed mesic forests. It is also common in wet forests. The koa's trunk was
Lesser koa finch Lesser koa finch The lesser koa finch ("Rhodacanthis flaviceps") is an extinct species of Hawaiian honeycreeper. The only specimens of the lesser koa finch ever caught were a family group with members of different ages and genders, ideal for study. The males were apparently golden-yellow with olive green on the breast and belly. The females were almost indistinguishable from the species' larger relative, the greater koa finch, other than the fact that the former were slightly darker in color. The juveniles were somewhat mottled on the belly, similar to the females. As its name suggests, the species as a whole