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
Koa Kannon in prison and has been likened to a “little Yasukuni Shrine”. On 12 December 1971 the East Asia Anti-Japan Armed Front, an extremist group, tried to blow up the statue of the Koa Kannon, the stone monument of the seven warriors, and the Memorial Stone of the 1,068 Executed Martyrs of the Great Pacific War, which they viewed as symbols of Japanese imperialism. The stone monument of the seven warriors was destroyed but because the fuse was short the other two escaped destruction. The monument which was destroyed was restored afterwards by volunteers. Unlike a typical temple, Koa Kannon has