Helleborus niger Helleborus niger Common name(s): Christmas Rose, Black Hellebore Blooming time: winter to spring Blooming colors: white Height: 20 to 30 cm Origin: Europe Hardiness zone (USDA): Z3 – up to -34 °C Family: Ranunculaceae During fading the petals turn greenish or reddish. Related plants:Aconitum carmichaelii Anemone blanda Caltha palustris Clematis vitalba Eranthis cilicica Eranthis hyemalis Helleborus orientalis Pulsatilla vulgaris Ranunculus asiaticus