A genus of perennial herbs (Helleborus) of the Crowfoot family, mostly having powerfully cathartic and even poisonous qualities. H. niger is the European black hellebore, or Christmas rose, blossoming in winter or earliest spring. H. officinalis was the officinal hellebore of the ancients.
- Any of various plants of the genus Helleborus, native to Eurasia, most species of which are poisonous.
- Any of various plants of the genus Veratrum, especially V. viride of North America, having large leaves and greenish flowers and yielding a toxic alkaloid used medicinally.