Acacia koaia Acacia koaia Acacia koaia, known as koaia or koaie in Hawaiian, is a tree in the pea family, Fabaceae, that is endemic to Hawaii. It is closely related to "koa" ("A. koa"), and is sometimes considered to be the same species. "Acacia koaia" is usually distinguished by growing as a short (rarely more than ), broad, gnarled tree; having the seeds longitudinally arranged in the pod; shorter, straighter phyllodes; and much denser wood. A population on the northern coast of Kauai may be intermediate, but the relationships have not been worked out. "Koaia" wood is claimed to be very different
ʻAnianiau Its call is a pair of notes, "tew-weet", while its song is a trill of "wee-see, wee-see, wee-see". Anianiau are found in mesic and wet forests at elevations above . The highest densities occur above . Dominant tree species in its habitat include koa ("Acacia koa"), ōhia lehua ("Metrosideros polymorpha"), ōlapa ("Cheirodendron trigynum"), and lapalapa ("C. platyphyllum"). The anianiau mainly feeds on nectar from the flowers of plants such as ōhia lehua ("Metrosideros polymorpha"), ōhelo ("Vaccinium" spp.), and alani ("Melicope" spp.). It will also take arthropods from trees, shrubs, or vines. The anianiau breeding season ranges from February to June.