Helleborus atrorubens Waldst. & Kit
It is easy to be confused by the application of this name to an uncommon, small flowered, Balkan species. For some time the name "Atrorubens" has been used for a small number of relatively showy, early flowering, purple coloured plants derived from H. orientalis subsp. abchasicus but there is no connection whatsoever between these two plants; here we are concerned solely with the wild species.
In the first edition of the Flora Europaea this plant was treated as a subspecies of H. dumetorum which occurs in the same area of north west Yugoslavia. However, if these two plants are viewed as sufficiently similar to unite into one species then botanists would be forced to halve the number of species by similar amalgamations. (This may yet turn out to be a sensible option!) The restricted distribution and demure appearance of this species have encouraged neither its cultivation in gardens nor comment in literature and these omissions have been obscured by the tendency in the past to treat it as a subspecies of H. dumetorum or, in earlier days, of H. viridis. In its best forms, though, it is a most attractive species which is slowly becoming better known and more widely seen in gardens.
This truly herbaceous species reaches about 12-18in (30-45cm) in height. The leaves are bold and similar to those of H. odorus in general appearance. They are roughly circular in general outline, 12-15in (30-38cm) across when mature, and are pedately divided into five leaflets with the outer one on each side again divided into three, four or five segments, giving a total of 9-15; 11-13 are probably the most commonly found numbers. The segments are noticeably elliptical in outline and are neatly saw-toothed, densely towards the tips, thinning out towards the base where the leaf is untoothed. The leaflets tend to arch out from their point of attachment to the stem, in a similar way to those of H. odorus. In the wild 10-25% of the plants have purple tinted young foliage but it is not at all downy. Few individuals have such richly coloured foliage as the wild collected specimen at Kew shown in Brian Mathew's book.
The flowers come in February and March with from 3-11 flowers per stem, with the stems more widely branched than those of other species giving the plant a distinctive open appearance. The topmost flowers are usually overtopped by slender or deeply cut bracts. The individual flowers are 11/2-2in (4-5cm) across, bell-shaped at first then gradually opening so that the petals may be almost reflexed by the time the seed capsules are fully developed. The individual petals are rather narrow and overlap only slightly so the result is a slightly starry flower; well-shaped flowers are in a distinct minority.
The flowers vary greatly in colour. They may be completely green, but are more usually reddish-purple backed but this colouring may be confined to the edges of each petal. Inside, those flowers with coloured backs may be stained to varying degrees by the colour seeping through at the edge. Occasionally the flowers may be deep purple in colour. The flowers tend to face outwards rather than nod; they are not scented. This is one of the earliest of the Balkan species to flower and in its native meadows it may be overgrown by taller meadow plants by May.
Confusion could arise with H. torquatus, H. dumetorum or H. purpurascens and in leaf with H. odorus. What makes this species unique is the combination of the distinctive foliage, reminiscent of H. odorus, with flowers which are quite different; even when the flowers are green they are dark compared with the yellow-green of H. odorus. Its foliage and the open habit of its flowering growth distinguishes it from other dark flowered species as does its tendency to reddish rather than blueish purple tints in the flowers.
Natural distribution and habitat
Helleborus atrorubens has a relatively restricted distribution in north west Yugoslavia, in particular south east Slovenia and north west Croatia between Ljubljana and Zagreb, within these areas it is locally common.
In the wild Elizabeth has found this species growing on limestone like most species, particularly on the north and east edges of beech and oak woods and in open meadows bordering the woods. It seems to prefer deep soils, either rich alluvial deposits or humus rich soil, and also occurs on roadsides and streamsides.
Amongst its companions on woodland margins are Anemone trifolia, Asarum europaeum, Cyclamen europaeum, Epimedium alpinum, Gentiana asclepiadea, Geranium phaeum, Hacquetia epipactis, Helleborus niger, Hepatica nobilis, Lamium orvala, Lunaria rediviva, Orchis morio, Polygonatum sp., Pulmonaria mollis and P. officinalis, Symphytum bulbosum and Vinca minor.
In more open situations it grows with Cytisus demissus, Hedysarum sp, orchids such as Orchis morio and Anacamptis pyramidalis, Polygola species, Salvia pratensis and a pink scabious.
There are plenty of clues for good garden groups amongst this wealth of interesting associates.
This species is best grown in leafy soil around the edges of shrubs and trees so that it benefits from at least partial shade. In gardens this is an easy and fast growing plant and needs plenty of space to develop. It seems particularly prone to slug and bird damage early in the spring and it pays to protect the emerging buds with slug pellets and a little brushwood.
This plant will be unfamiliar to most gardeners. Although The Plantfinder has now segregated H. atrorubens from "Atrorubens" many gardeners (not to mention nurseries) have yet to appreciate the distinction.
Helleborus atrorubens is an interesting rather than flamboyant plant but in its best forms its purple flushed flowers with their green tinted interiors are well worth close inspection. This modest species can easily be overlooked amongst more showy neighbours and dainty small flowered plants are perhaps its best companions. Its neighbours in the wild give plenty of ideas, Hacquetia epipactis and Hepatica nobilis would be especially good choices. It would be lovely with the form of Geranium phaeum known as 'Samobor', found growing with it in the wild, which has bold dark marks on its foliage. An early white primula like 'Schneekissen' or 'White Wanda' would provide a delicate contrast as would snowdrops.