Epipactis - Helleborines

Broad-leaved Helleborine, Epipactis helleborine

Above: A particularly purple Epipactis helleborine the Broad-leaved Helleborine. More usually, the flowers are greener and flushed with pale pink, as in the specimen below. Could this be var. purpurea or a hybrid between Broad-leaved and Violet helleborines? How can we tell? The leaves of Epipactis helleborine are broad and quite dark green, though sometimes tinged purple (especially in exposed places where anthocyanin production is triggered by bright sunlight) and with parallel venation. The flower spike is often 1 to 2 feet tall (30 to 60 cm) but may reach 4 or 5 feet (120 to 150 cm) and may bear a dozen to about 100 flowers. Some plants produce multiple spikes. In the British Isles, it flowers from early July to late August, but mostly from mid-July to mid-August.

Many walk past Epipactis helleborines (the other type of helleborines belong to the genus Cephalanthera) without really noticing them: the flower spikes may be tall, but the flowers often face all the same way and may droop and so conceal their beauty from casual observation. A closer inspection, however, will reveal their incredible beauty!

This species is widely distributed throughout most of Europe and the Mediterranean regions of North Africa and as far east as the Himalayas. It is widely naturalised in parts of North America, following its introduction, where it may be invasive and problematic. It also occurs naturally in parts of Asia, but whether it becomes a different species this far East has been the subject of debate.

This species of orchid is highly variable, especially in flower colour, but also in leaf shape. Variations in flower colour are thought to be chiefly genetic. There are also other species of Epipactis, such as the violet Helleborine (Epipactis purpurata) which can potentially be confused with Epipactis helleborine, except that it generally has narrower leaves and the bosses on the lip are smoothly pleated and pink. In Epipactis, the lowermost petal, forming the lip or labellum, is divided into the basal nectar-cup or hypochile and the heart-shaped leaf-like tip or epichile. The epichile bears a pair of protuberances or bosses at its base. In Epipactis helleborine these are usually narrow and brownish, as can be clearly seen above and below. However, the bosses are apparently quite variable. Furthermore, Epipactis helleborine can cross with Epipactis purpurea and the hybrid, Epipactis x schulzei is fertile. In the British Isles Violet Helleborine is found in southeast England and the Midlands and is less common than the Broad-leaved Helleborine which is more widespread throughout the British Isles. The specimen above is possibly the fertile hybrid with Violet Helleborine, Epipactis x schulzei.

Epipactis helleborine is found chiefly in deciduous woodland, especially beechwoods and the better lit areas, such as the woodland edge. It can occur in open grassland, scree, on cliffs and limestone pavements and dune slacks but favours cooler and damper areas. It has also been found in pine plantations and on acidic heaths or under birches amongst braken. Epipactis purpurata grows in similar woodland habitats but more strongly associated with calcareous soils, and can better tolerate heavy shade.

The Narrow-lipped Helleborine, Epipactis leptochila also occurs primarily in deep shade in ancient beechwoods on chalk and, although much more local in its range in the British Isles, can potentially occur along with Broad-leaved and Violet helleborines in some localities. It can be distingushed by its narrower, arrow-head shaped epichile which ends in a distinctive point.

Green-flowered Helleborine, Epipactis phyllanthes can also occur in similar habitats, but has not been recorded from the area where these photos were taken. The lip of Epipactis phyllanthes is extremely variable, with some forms even lacking a hypochile.

Above: a more typical variety of Epipactis helleborine, with narrow brownish bosses and flowers flushed light pink. The hypochile cup collects nectar. Some individual helleborines have loosely-packed flowers which are well separated on the spike, whereas in others the flowers are extremely densely packed. Summerhayes (V.B. Summerhayes, Wild Orchids of Britain, in the New Naturalist series, Collins (pub.)) noted that plants growing in shade tend to have more loosely packed spikes. The colours of the various appendages of the flower may vary from yellowish-green to a deep red. Next time you come across helleborines, why not take a
closer look at the variation within the population?

Life-Cycle

The fascinating pollination mechanisms of Epipactis have been discussed here. It is pollinated by wasps, especially Dolichovespula. Self-pollination is probably rare in this species (in contrast Epipactis phyllanthes is always self-pollinated).

The deep-seated and woody rootstock is short and thick and slowly grows upwards. This sends out a number of deep roots, enabling the plant to tolerate relatively dry soil, though damp spots are preferred. In soils rich in humus the roots host mycorhizal fungus, such as truffles, which may be absent on more mineral-rich soils. Some of these mycorhizae may associate with the roots of trees, perhaps enabling Epipactis to obtain some nourishment from nearby trees via the fungal mycelium. It obtains most of its nitrogen and some of its carbon from its fungal partner. This species is perennial and may be long-lived. Some years the plant may remain entirely underground, nourished by its fungal partner, other years it may put up leaves without flowering. Some Epipactis may live for decades and possibly centuries, as has been
suggested for the Violet Helleborine.

Violet Helleborine, Epipactis purpurata

The Violet Helleborine, Epipactis purpurata (Epipactis violacea) is a lover of shaded places and is said to reach its 'best' development in the shaded interior of beechwoods where few other plants will grow (though may be accompanied by Green-leaved Helleborine (Epipactis leptochila)or Broad-leaved Helleborine, though Broad-leaved Helleborine is considered to have a preference for the lighter parts of these woods. However, Violet Helleborine may also be found along the edges of trackways in woods where there is more light.

The leaves of Violet Helleborine are generally more than twice as long as broad, even at the base, whereas in Broad-leaved Helleborine this is not the case as the basal-most leaves in particular are less than twice as long as broad or at least more oval in shape. The leaves of Violet Helleborine also become more oval towards the base but tend to be smaller and more distinctly tapered to a point at the tip. They may be distinctively streaked with purple, but not always, and the leaves of Broad-leaved Helleborine may also be tinged purple. The flowers of Violet Helleborine are often said to be larger, what I have noticed is that the lateral sepals are longer and open more widely. The stems are also more darkly coloured, grey-green and often strongly washed with purple and the leaves a darker green.

More diagnostic features are the bosses or bumps near the base of the epichile are more vertically elongated in Violet Helleborine and more like smooth pleats, whereas those of Broad-leaved Helleborine are short, wide and coarser in appearance. The epichile of Violet Helleborine is also more elongated and heart-shaped. The ovary of Violet Helleborine has a noticeable covering of short fine hairs with a matte finish whereas that of Broad-leaved Helleborine is noticeably less hairy, appearing glabrous and glossy. The flowers of Violet Helleborine also tend to be more lightly coloured and the petals greenish or violet, the sepals green. The stems of Violet Helleborine also often clustered together.

Above: the basal leaves of Violet Helleborine.

The roots of Violet Helleborine grow vertically downwards and are slow growing, with only one or two new roots forming each year, though old plants may have as many as 50 (Summerhayes 1951). The roots are borne on a short vertical rootstock (rhizome) and may penetrate the soil to about 1 m depth (occasionally the roots are 120 cm long). A single flowering stem may be produced at first, but as the plant matures several buds from the rootstock may form each year, producing a cluster of stems. The flowering stems reach a height of about 1 to 3 feet (30 to 90 cm).

The preferred habitat of Violet Helleborine is woodland, particularly beechwoods along with Bird's-Nest Orchid (Neottia nidus-avis), Dog's mercury (Mercuralis perennis), brambles (Rubus spp.), ivy (Hedera helix) and ferns (e.g. Dryopteris filis-mas) along with Green Helleborine and Broad-leaved Helleborine. It favours clay-flint soils on chalk downs. It may be found in oak-hazel woods.

There is some uncertainty as to how the Violet Helleborine obtains its nutrients. The roots of mature specimens are said to be free of mycorrhizal fungi and yet the plant can not be entirely dependent on photosynthesis, since the rare variety rosea lacks chlorophyll and this plant is a rose-pink colour with whitish flowers but grows and flowers successfully. This suggests some dependence on fungi as does the healthy growth of this plant in deep shade despite its small leaves. It may well subsidize its photosynthesis by digesting fungi in its roots (mycoheterotrophy). A plant of about 30 years of age may still bear a single flower spike and some consider the large multi-stemmed plants to be centuries old.

Above: a specimen reaching into comparative light allowed a good resolution photograph. The flowers here are just starting to 'go-over' and have opened to their maximum extent.

Further Reading

Summerhayes, V. S. 1951. Wild Orchids of Britain. Collins, The New Naturalist series.

Harrap, A. and Harrap, S. 2009. Orchids of Britain and Ireland. Second ed. A & C Black, London.

Article created: 23/7/2017
updated: 8/8/2019
reformatted: 16/11/2019