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 Hawaiʻi, Maui and Oʻahu. Its name in the Hawaiian language, koa, also means brave, bold, fearless, or warrior. A closely related species, koaiʻa or koaiʻe (A. koaia), is found in dry areas. It is most easily distinguished by having smaller seeds that are arranged end-to-end in the pod, rather than side-by-side. The phyllodes are also usually straighter, though this character is variable in both species. The wood is denser, harder, and more finely grained than koa wood. Koaiʻa has been much more heavily impacted by cattle and is now rare, but can be seen on ranch land in North Kohala.