Delissea is a genus of soft-wooded shrubs, treelets, and palm-like trees endemic to the seven largest Hawaiian Islands; it is most closely related to the endemic Hawaiian genus Brighamia. Delissea is characterized by fleshy, glabrous, petiolate leaves drying membranous or slightly chartaceous and almost translucent; axillary racemose inflorescences with usually ebracteolate pedicels; small tooth-like calyx lobes; white or greenish bilabiate corollas with the curved tube slit dorsally for less than half its length and a distinct knob at the base of this slit (sometimes flanked by a pair of lateral knobs); free exserted staminal column; small dark purple thin- walled berries; large, dull white, transversely rugose seeds; and a chromosome number of 2n=28. Fifteen species, each endemic to a single island, are recognized here and divided among three sections on the basis of habit and floral features.