Acacia koa Acacia koa Acacia koa is a species of flowering tree in the pea family, Fabaceae. It is endemic to the Hawaiian Islands, where it is the second most common tree. The highest populations are on Hawaii, Maui and Oahu. Its name in the Hawaiian language, koa, also means brave, bold, fearless, or warrior. Koa is a large tree, typically attaining a height of and a spread of . In deep volcanic ash, a koa tree can reach a height of , a circumference of , and a spread of . It is one of the fastest-growing Hawaiian trees, capable of
Koa wilt mortality rate over several years due to Koa wilt. It is also a legume, giving it the ability to form symbiosis with nitrogen fixing bacteria, which has led to efforts to use koa in agroecological systems with crops such as coffee and cacao. Ecologically, koa is an important species because it is one of the few native trees that remains dominant in alien mixed forests on the Hawaiian Islands. Invasive species make up the majority of the State's current plant population. Koa trees also are important because provide a habitat for many native bird species. Historically, there were once two