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 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. Koaia has been much more heavily impacted by cattle and is now rare, but can be seen on ranch land in North Kohala. The koa population has suffered from grazing and logging. Many wet forest areas, where the largest koa grow, have been logged out, and it now comes largely from dead or dying trees or farms on private lands. Although formerly used for outrigger canoes,