Hibiscadelphus giffardianus viscosa"), and naio ("Myoporum sandwicense"). "H. giffardianus" is a small tree, reaching a height of and trunk diameter of . Hibiscadelphus giffardianus Hibiscadelphus giffardianus (Kilauea hau kuahiwi) is a species of flowering plant in the mallow family, Malvaceae, that is endemic to the Big Island of Hawaii. It is believed to be extinct in the wild; any remaining plants are threatened by habitat loss. Cultivated plants exist in Hawaii Volcanoes National Park. It inhabits mixed mesic forests on the slopes of Mauna Loa at elevations of . Associated plants include ōhia lehua ("Metrosideros polymorpha"), koa ("Acacia koa"), mānele ("Sapindus saponaria"),
Acacia koa reaching in five years on a good site. Initially, bipinnately compound leaves with 12–24 pairs of leaflets grow on the koa plant, much like other members of the pea family. At about 6–9 months of age, however, thick sickle-shaped "leaves" that are not compound begin to grow. These are phyllodes, blades that develop as an expansion of the leaf petiole. The vertically flattened orientation of the phyllodes allows sunlight to pass to lower levels of the tree. True leaves are entirely replaced by long, wide phyllodes on an adult tree. Flowers of the koa tree are pale-yellow spherical racemes with