Notes on Hellebores
By Dr. Mary Toomey

Central and southern Europe, Ukraine and eastern Romania are home to most species of hellebore (from two Greek words: hellin, to kill and bora meaning food). There are 16 wild species and 5 hybrid species. Species such as H. niger, the Christmas rose and H. orientalis have been grown in gardens since the 17th century. However, H. thibetanus was only introduced to cultivation in 1991, in spite of having been discovered in China by the French missionary, Père Armand David almost 132 years ago. H. viridis and the stinking hellebore, H. foetidus are native British species. Some of the finest and most garden-worthy hellebores are derived mainly from four species: H. orientalis, H. argutifolius (syn. H. corsicus), H. foetidus and H. niger.

Distinguishing features

Although the genus Helleborus shares a number of general characteristics with the other members of the family Ranunculaceae, it is distinguished from most of the allied genera by the following features:

• Fruit consists of a cluster of follicles (carpels, which normally split lengthways when fully ripe), which may be free from each other or joined to varying degrees at the base. In the case of H. vesicarius the follicles do not split.
• The sepals persist throughout the life of the flower. The outer whorl of the hellebore flower consists of five sepals, which are petal-like, and the inner whorl of true petals, are modified into funnel-like nectaries. The nectaries form a distinct ring beneath the stamens. In some cultivars, which boast double flowers, the nectaries revert to true petals, and therefore, the flowers are made of sepals and petals.

Stemmed (caulescent) or Stemless (acaulescent) Hellebores?

While it may be convenient from a horticultural point of view to separate hellebores into stemmed and stemless groups, more recent research shows that many apparently stemless species, in fact, have contracted stems from which emerge leaves and flowers. Therefore, all hellebores have stems. However, some have true, tough stems, from which are produced leaves and flowers, e.g. H. argutifolius (commonly referred to as H. corsicus), H. foetidus, H. lividus, while others have flowering stems, which bear no true leaves. They have instead small bracts (cauline leaves), which are leaf-like, and have a somewhat woody underground rhizome, producing shoots with basal leaves, and flower stems devoid of leaves e.g. H. atrorubens, H. cyclophyllus, H. dumetorum, H. odorus, H. multifidus, H. orientalis, H. purpurascens, H. torquatus, H. viridis. In the widely known and grown Christmas rose, H. niger, the leaves are all basal and the flower stems have no proper leaves. Furthermore, the bracts are not divided and do not resemble the reduced leaves in other stemless species.

Both stemmed and apparently stemless hellebores share the following features:

• All species hellebores set viable seed quite freely, in at least most cases, and the seed germinates readily and easily, provided it is sown fresh. Germination tends to be somewhat erratic if it is stored for too long.
• All species with the exception of H. lividus and H. vesicarius are frost-hardy and grow successfully in a wide range of situations.
• Hellebores cannot be propagated by cuttings.