Primitive koa finch viscosa") berries, as these were observed being eaten by other species in the genus. The primitive koa finch is believed to have gone extinct some time after Polynesians first arrived in Hawaii, however very little else is known about this species. Due to its early extinction it is only known from fossil remains. Other Hawaiian honeycreepers are known to have become extinct or very rare due to habitat loss, introduced predators and avian diseases. It is possible the extinction of the primitive koa finch also involved these factors. BirdLife International 2004. Himatione sanguinea. 2006 IUCN Red List of Threatened Species.
Leaf nearly petiolate or have an extremely short petiole and may appear to be sessile. In clasping or decurrent leaves, the blade partially surrounds the stem. When the leaf base completely surrounds the stem, the leaves are said to be perfoliate, such as in "Eupatorium perfoliatum". In peltate leaves, the petiole attaches to the blade inside the blade margin. In some "Acacia" species, such as the koa tree ("Acacia koa"), the petioles are expanded or broadened and function like leaf blades; these are called phyllodes. There may or may not be normal pinnate leaves at the tip of the phyllode. A