A genus of about 40-50 species of perennial herbaceous flowering plants, native to temperate regions of North America and Asia. They used to be treated in the family Trilliaceae or Trillium family, a part of the Liliales or Lily order.

Common names include trillium, wakerobin, Tri Flower, and birthroot. The above ground parts of Trilliums are scapes with three large, leafy bracts with the true leaves reduced to underground papery coverings around the rhizomes.

from: Wikipedia