Hellebores (commonly known as Winter Roses) are herbaceous perennial plants. They mostly originate in inland regions of central and southern Europe.
The main concentration of Helleborus species in the wild is found in the Balkans. Hellebores are found as far West as Spain and Britain and as far east as Turkey and the Republic of Georgia. Helleborus argutifolius and H. lividus are found on the Mediterranean islands of Corsica and Majorca respectively.
But by far the most geographically isolated species is the rare Chinese species Helleborus thibetanus, cut off by 5,200km from its nearest Helleborean neighbour. Recent research suggests that Helleborus species may have once had a continuous distribution from Europe to east Asia. However major geological and climate changes cut off what is now H. thibetanus about 23 million years ago (1).
The habitat in which Hellebores are found in the wild is reasonably diverse. This ranges from semi-alpine to quite hot and dry low altitude areas. However they are mostly plants of semi shaded conditions, such as the edges of deciduous woodland, dryer in summer and damp in the cooler months. Hellebores are more tolerant of exposed sunny positions in cooler, high altitude regions.
The genus Helleborus has been placed within the Ranunculaceae family by Botanists. Other related genera in this family include Aquilegia, Clematis and Delphinium. As with some other members of the Ranunculaceae family, Hellebores are poisonous.
There are about 17 different species of Helleborus. The most basic way to divide the genus for horticultural purposes is between the ‘caulescent’ (stemmed) and ‘acaulescent’ (unstemmed) species. H. argutifolius is an example of a caulescent species. It has a well developed above ground stem which carries both true leaves and flowers. The acaulescent species (eg. H. atrorubens) are shorter clumping plants with separate leaves and flower stems. This split enables an understanding of the basic growth habit of the different species. H. niger is the exception, not sitting easily in either group.
A summary of the Helleborus species (2):
Several of the different Helleborus species will hybridise with each other. H. argutifolius and H. lividus are closely related and will hybridise to give the fertile hybrid H. x sternii. H. niger will hybridise with these two species and their hybrid, giving rise to the infertile interspecific crosses H. x nigercors (hybrid with H. argutifolius), H. x ballardiae (H. lividus) and H. x ericsmithii (H. x sternii). Helleborus niger will also hybridise with H. thibetanus and H. vesicarius. All of the Hellebore species in the Helleborastrum section will hybridise readily.
Helleborus x hybridus are the most commonly found Hellebores in the garden. For years labelled incorrectly as ‘H. orientalis’ or ‘H. orientalis hybrids’. As it is now recognised that several different acaulescent species have been involved in the development of these garden origin hybrids over the past 200 years, H. x hybridus is now recognised as the correct name (3).
- Sun H., McLewin W. and Fay M. (2001) “Molecular phylogeny of Helleborus (Ranunculaceae), with an emphasis on the East Asian-Mediterranean disjunction” Taxon, 50:1001.
- Based on a) Sun H., McLewin W. and Fay M. (op.cit.) and b) McLewin W. and Mathew B. (2002) “Helleborus Viridis”, The Plantsman, 1(3): 150-153
- McLewin W. and Mathew B. (1998) “Helleborus orientalis and Helleborus x hybridus” The New Plantsman, 5(2): 117-124.