Synonyms for Black Hellebore (same or very similar meaning)
WordNet sense 1 (slightly hairy perennial having deep green leathery leaves and flowers that are ultimately purplish-green):
lenten rose, Helleborus orientalisWordNet sense 2 (European evergreen plant with white or purplish roselike winter-blooming flowers):
Christmas rose, Helleborus niger, winter roseFrom the ODE community, based on WordNetadd/edit