Helleborus abchasicus Helleborus kochii Helleborus officinalis Helleborus olympicus Helleborus ponticus Helleborus caucasicus Helleborus orientalis subsp. abchasicus Helleborus orientalis subsp. guttatus Helleborus antiquorum Helleborus heyderi Helleborus guttatus
World Flora Online, http://www.worldfloraonline.org/, accessed June 20, 2024