Helleborus cyclophyllus (A. Braun) Boissier
This is one of the two most widely grown green-flowered species and a fine garden plant. However, it is still found mainly in specialist collections although it is one of three species which have been used in the creation of yellow flowered hybrids. In gardens H. cyclophyllus can easily be confused with H. odorus and it is so difficult to separate the two that it is tempting to think of them as northern and southern forms of the same species. There seem no certain ways of telling the two species apart, other than geographical ones, as the botanical differences are not constant.
Usually behaving as a truly herbaceous perennial and losing its leaves in winter, this species reaches a height of 16-22in (40-55cm). The young emerging leaves may have a slightly reddish tint and are covered in a fine coating of silvery hairs on the undersides, which becomes less pronounced as the foliage matures, eventually disappearing on most plants. The mature leaves are almost completely round in overall shape, each leaflet arching over fountain fashion.
Plants from different wild populations vary in the number of leaf divisions, while plants in gardens also vary in this respect according to their maturity and general vigour. There are usually seven main segments to each mature leaf, all undivided except the outer one on each side which can be divided into as many as three parts giving up to about eleven individual segments. However having inspected plants in various parts of its wild range, Jim Archibald reports anything from eight to twenty five segments. The leaves do not usually overwinter except sometimes in northern populations where it approaches and even meets H. odorus.
Helleborus cyclophyllus starts to flower as early as January but is usually at its best in February and March. There are up to about seven flowers per stem, each about 2-21/4in (5-6cm) across. Like the foliage, the flowers are rather variable and even in single populations can vary noticeably in shape and size. They may be perfect in bud but open to give rather lopsided flowers with uneven petals. The late flowers can also be less than half the size of early flowers on the same plant. In the far north east of its range the flowers become distinctly creamy in colour while in most plants they are dark green or yellow-green. Some petals in an individual flower may be the green of French 'Golden Delicious' apples while others may be yellower.
The nectaries also vary from green to honey coloured and while the carpels of this species should not be joined at the base, in most populations some of the plants have carpels which are fused at the base. Some, but not all, plants may have a scent which is usually reminiscent of Ribes.
There is no one special feature which distinguishes H. cyclophyllus from other species. The unfused carpels and the absence of overwintering foliage (in most areas) should distinguish it from H. odorus although in many areas where H. odorus spends the winter under snow, the foliage is not evergreen. It is distinct from other species in the area in its larger green flowers. The tendency in both species to deciduous foliage and the occurrence of populations of H. cyclophyllus with fused carpels, some a great distance from what would be considered true H. odorus, would appear to indicate affinity with, hybridisation with or synonymy with H. odorus.
It is distinguished from most forms of H. multifidus by its relatively undivided foliage, its strong, bold, upright growth and its larger flowers while H. dumetorum and H. viridis have smaller, unscented flowers. In the north east corner of Greece the distribution of H. cyclophyllus approaches the most westerly area for H. orientalis and hereabouts the flowers of H. cyclophyllus take on a suspiciously creamy tint.
Additional confusion is created by the fact that this species also overlaps with H. torquatus in southern Serbia and hybrids occur, some of which have the distinctive foliage of H. cyclophyllus combined with purple flowers.
Natural distribution and habitat
Helleborus cyclophyllus grows wild in northern Greece extending into the northern Peloponnese (but no further south), most of Albania (although this area has not been extensively studied), southern Yugoslavia and southern Bulgaria. It is also found in Corfu and the fine plant distributed by Blackthorn Nursery as H. odorus may belong here.
It grows wild on the margins of oak, ash or beech woodland or in scrub, but also sometimes on open grassy slopes. It is typically a mountain plant, but not exclusively so and like other hellebores, favours limestone country. In southern Serbia and Macedonia it grows in a range of habitats from dry, bare slopes and grassy banks to dense scrub. Amongst scrub oaks and pines in the Pindhos Mountains on the Greeck/Bulgarian border it sprouts amongst the little white-flowered Primula vulgaris var. pulchella and later flowers with Dactylorchis sambucina and Fritillaria graeca.
At the Katara Pass in Greece John Richards reports it in company with Narcissus poeticus and Primula veris with some Fritillaria pontica, Daphne blagayana and Soldanella pindicola. Jim Archibald also reports it from this area but points out that it varied greatly both in its flower size and the number of leaf divisions (up to 25).
High in the Stara Planina range in central Bulgaria it grows in pastures with Digitalis ferruginea while further west, in the Prizren Bistrica Gorge in Kosovo sandwiched between Albania and Macedonia, copses of Acer campestre, A. monspessulanum, A. tartaricum, Carpinus orientalis and Euonymus europaeus occur and on their fringes H. cyclophyllus is found, sometimes in bud at Christmas and tolerating severe frost and snow.
On the higher slopes of Mount Parnassos much further south, its fat clumps set off the many bulbs very effectively. Amongst its neighbours on this ancient site are Colchicum triphyllum, Corydalis bulbosa and C. solida, Crocus biflorus, C. sieberi and C. veluchensis in a variety of shades, Fritillaria graeca, Gagea arvensis, Muscari botryoides and M. neglectum, Ornithogalum exscapum and O. oligophyllum, and Scilla bifolia. The frequency with which H. cyclophyllus occurs here suggests that this is indeed the plant referred to as the black hellebore in classical Greek literature.
In the wild H. cyclophyllus tends to be found in woodland and dense scrub less often than many species, the plants usually concentrated in more open positions at the woodland fringes. This should be kept in mind when considering where to plant in the garden and a more open position chosen than for many species. Shelter from spring frosts and drying winds is also necessary and this can be provided by evergreen shrubs and by mounding up loose, dry leaves.
Because of its southern distribution this species is inclined to start into growth too early in the season and be hit by frost. Although hellebores are almost impervious to frost damage, bowing to the ground when frozen and standing upright again when thawed, repeated frosting is debilitating and apt to leave H. cyclophyllus susceptible to attack from black spot. Collections from northern areas and at high altitudes are likely to be hardier although this may not always be specified.
This, along with H. odorus, is one of the two green flowered species most commonly found in gardens. Jim Archibald has distributed a number of rather variable forms from distinct populations in Greece and Yugoslavia although some of these might be attributed to H. odorus. Others have also made it available but it is not widely grown other than in gardens of hellebore enthusiasts. However this can be a very impressive plant both in flower and in leaf and deserves to be grown more widely especially as relatively few large, green-flowered Orientalis Hybrids are grown as yet. It looks wonderful with blue bulbs such as Muscari latifolius and M. neglectum or the brilliant blue x Chionoscilla allenii. Yellowish flowers make a good match and amongst bulbs you might try Crocus chrysanthus 'Cream Beauty' or Galanthus nivalis var. lutescens while for perennials there is Euphorbia polychroma and Digitalis grandiflora. The flowers are also very pretty floating in water amongst flowers from brighter forms.