Ranzania (トガクシソウ, Togakushisou) is a monotypic genus of perennial herbs in the family Berberidaceae.
This genus is named in honor of Ono Ranzan, who has been called "the Japanese Linnaeus".
[1] Fleshy stems of Ranzania form small colonies from an underground rhizome.
Each stem bears two trifoliate compound leaves, and between the leaves is a single or more commonly a small cluster of drooping cup-shaped mauve flowers.
These develop into an upright cluster of white berries.