Trillium is a genus of about 40–50 species of spring ephemeral perennials, native to temperate regions of North America and Asia. It used to be treated in the family Trilliaceae or Trillium family, a part of the Liliales or Lily order. The above ground parts of Trilliums are scapes with three large, leaf-like bracts with the true leaves reduced to underground papery coverings around the rhizomes.
A white trillium serves as the emblem and official flower of the Canadian province of Ontario.