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
ʻApapane Lānai. Apapane generally feed on nectar from flowers, preferably from the "ōhia lehua" ("Metrosideros polymorpha") tree. These birds are mainly found in "koa" ("Acacia koa") and "ōhia lehua" forests where the flower count is high. Although primarily nectarivorous, the diet of a grown apapane also includes a variety of insects like grasshoppers, caterpillars and bugs of all sorts. The breeding season is from January through July. The nest of the apapane is usually placed in the crown of a "ōhia lehua" ("Metrosideros polymorpha"); nests have been found in tree cavities and lava tubes as well as in the top of