birthroot

noun

1. Also called birthwort, purple trillium. a trillium, Trillium erectum, the roots of which were formerly used in medicine as an astringent.
2. any of certain other species of trillium.

noun

1. any of several North American plants of the genus Trillium, esp T. erectum, whose tuber-like roots were formerly used by the Native Americans as an aid in childbirth: family Trilliaceae