It's commonly called Japanese fatsia or false castor oil plant, and is synonymous with Aralia japonica. The name Fatsia may be a mispronunciation of the Japanese 'hachi' (eight), referring to the number of lobes on each leaf.
It has large fat, shiny green leaves with eight lobes and can grow up to 2m/6ft as a mature plant.
Fatsia is very adaptable to a wide range of conditions although it prefers a sheltered but bright position away from draughts and a moderate temperature. It can be placed outdoors in the summer, where the leaves become a deeper shade of green. Feed weekly and give it plenty of water. It is a quick grower and to encourage its growth, pinch it out from time to time. Prune to improve its shape, and clean the leaves with a damp cloth and do not use leaf shine.
Fatsia japonica was a favourite with the Victorians.