hellebore

noun

1. any of a genus (Helleborus) of poisonous, winter-blooming plants of the buttercup family, with buttercuplike flowers of various colors: the rhizomes of a black European species (H. niger) were formerly used as a heart stimulant and cathartic
2. any of a genus (Veratrum) of poisonous plants of the lily family: the (V. album) and the (V. viride) were formerly used as cathartics, etc.