There are 28 described species in the genus and a number of undescribed species, all small, resinous trees of the subtropical and tropical Pacific Ocean, characterized by huge, simple leaves and a dioecious sexual system, a unique combination in Araliaceae.
The genus comprises 28 documented species and several unidentified species, all tiny, resinous trees native to the subtropical and tropical Pacific Ocean, distinguished by massive, uncomplicated leaves and a unique reproductive system, a distinctive feature of Araliaceae.