Epipactis, the helleborines and other summer-flowering orchids of the southern UK.

David Beeson, August 2021

PLUS: photographs of plants on Eastern Salisbury Plain Army Training Area.

But, firstly let us separate the two different genera of ‘helleborines’. There are Epipactis and Cephalanthera helleborines.

The Cephalanthera genus contains the white, red and narrow-leaved helleborines. The white helleborine I find locally, sometimes in good numbers. I associate it with beech woodlands, yet given a chance it will spread to thin chalky soils on the woodland edge. The red helleborine is very rare in the UK, yet much more widespread on mainland Europe – Slovenia, France and Switzerland. The narrow-leaved type I encountered only once on a Hants Wildlife Trust reserve in east Hampshire. All flower in early summer.

Outlines of where to seek these plants out are available, for example in: The Flora of Hampshire by Brewis, Bowman and Rose. Harley Books.

Epipactis: Most of us would be allowed to think that many of these helleborine ‘species’ are just variants of one species. They are strikingly similar. Of course, all organisms show variability due to genetic changes and those between the different members of the genus Epipactis are no different.

Marsh Helleborine. The three purple ‘petals’ are sepals. There are two petals plus the labellum (pointing down). The yellow structure contains the reproductive parts.

Epipactis have much chunkier flowers than the other genus, and they are at their best in July through to August. I first encountered the genus on a NNR in wet, sand-dune slacks at Ynyslas near Borth in West Wales. This was the Marsh Helleborine, a species also found on Stockbridge North Fen and around the Basingstoke Canal.

Epipactis palustric is beautiful and spreads easily vegetatively. However, my attempt to establish it from purchased plants was unsuccessful. (Plant World Seeds sell packets of the dust-like seeds, and I have bought some to try again.)

The other local species grow in much drier habitats, often associated with beech trees.

The plant most likely to be encountered is Epipactis helleborine, Broad-leaved Helleborine. It is said to be locally common – but not in my estimation! I consider it rare, but it occurs far up into Scotland. This plant may show its flowers as late as October.

It is described as: A tall (75 cm) orchid of woodland and scrub, the Broad-leaved Helleborine has greenish, purple-tinged flowers that look a little ‘drooping’. Strongly veined, oval leaves spiral around its stem. Its habitats include deciduous and coniferous woodland, shady banks, streamsides, roadsides, dune-slacks, limestone pavements, screes and hedgerows. It also occurs in urban habitats, particularly abandoned gardens, and said to be more common in Glasgow than anywhere else in Britain.

The nutrition of the Broad-leaved Helleborine and its relatives is interesting. They obtain much of their carbon and nitrogen compounds from trees (yes, trees!). This is through soil fungi that provide the conduit. The plant can grow even when respiration is consuming more energy than arrives from photosynthesis – hence why they can grow in dark environments.

(In the US it is sometimes referred to as the ‘weed orchid’ as it is an introduced species which has spread rapidly.)

Some species of wasp and bee that are attracted to broad-leaved helleborines have been noted as becoming ‘intoxicated’ after visiting these orchids for nectar – it appears that the flowers can contain a kind of alcohol as a result of a fungus! The bees like it so much, they come back for more, ensuring the flower is potentially pollinated.

Because the different dry-land Epipactis types are so similar I investigated their DNA. Well, I wish I hadn’t! It is a real mish-mash and I ended up confused, but deciding they may well just be variants of one species. But, the books record them as separate species. Why the problem? They are mostly self-pollinating, so mutations can stimulate differences that repeat. (BSBI website is worth investigating for serious botanists.)

Separate species (genetic variants?) include Violet Helleborine with purple stems and leaves, Narrow-lipped Helleborine and Green-flowered Helleborine.

Epipactis phyllanthes occurs in scattered colonies throughout England in Dorset, Kent, Norfolk and Cumbria. In Wales it occurs in some coastal dune systems, particularly at Kenfig National Nature Reserve, Whitford Burrows and Morfa Dyffryn. In Flintshire it occurs in woodland. In Ireland there are sites in Co. Dublin, Leitrim and Fermanagh.

Epipactis phyllanthes is also recorded in parts of western Europe from Denmark south to Belgium, France and northern Spain.

The Hardy Orchid Society has practical sessions to aid your growing of UK orchids from seed. They also organise field trips.

See  https://www.hardyorchidsociety.org.uk

My visit to Salisbury Plain was organised by Wiltshire Botanical Society.

Below are more images taken on the field trip. These are some of the more unusual / interesting plants; there are huge numbers of other species.

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