Helleborus species and their distribution
Helleborus, with its various different species, belongs to the buttercup family (Ranunculaceae), along with other popular genera, such as clematis (Clematis), delphinium (Delphinium) and globeflower (Trollius).
Distribution of the Helleborus genus of approximately 20 species is limited to the northern hemisphere including Europe and Asia. Some species are very distant from each other in terms of both descent and properties.
Classification according to B. Mathew
Brian Mathew divided the Helleborus species into six groups in 1989. The classification is based on the following – usually morphological – parameters:
- type of growth (presence or absence of stem)
- properties of leaves and seeds (carpels grown together or separate, anther shape and properties, seed size and shape)
- differences in the leaf and flower colours
- habitat requirements
- ability to hybridise