Stephaniajaponica is the name of a species, part of the genus Stephania.
This name is an alternative combination by Miers of an original description of species by Thunb. under the rules of the International Code of Nomenclature for algae, fungi, and plants (ICN / commonly called the botany code)..
Stephaniajaponica (Thunb.) Miers var. discolor (Blume) Forman
Stephaniajaponica (Thunb.) Miers var. timoriensis (DC.) Forman