Orchids of the British Isles - Helleborines (Cephalanthera)
Created | Updated Oct 12, 2015
Orchids of the British Isles - Introduction
Animal Nomenclature | Orchids of Bogs, Fens and Marshes | Dactylorhiza | Helleborines (Cephalanthera) | Helleborines (Epipactis) | Insect Mimics
Lady's Slipper Orchid | Miscellaneous Orchids | Orchis | Saprophytes | Tresses | Twayblades
Helleborines are divided into two genera, Epipactis and Cephalanthera. This Entry will focus on Cephalanthera.
Red Helleborine Cephalanthera rubra
This beautiful orchid is another critically endangered one and it only survives in three locations in the UK.
The leaves of this orchid are long and pointed. They grow in pairs up the flowering stem and, like the white helleborine, they have leaf-like bracts where the flower buds appear. The stem can reach up to 60cm and bear up to six flowers.
The flowers are violet-pink in colour and open much wider than the other helleborines in this group. The three outer petals are held away from the stem, and form a triangle shape. Two inner petals meet to form a hood covering the lip of the flower, which looks like a tongue sticking out. The lip itself is violet-pink, with orange ridges leading into the centre of the flower.
It is thought that a male masonry bee, Osmia caerulescens, may pollinate this plant. Though this bee is seen to visit the flowers, there is no record of it actually pollinating the orchid. Seed production is very poor, this may be due to the lack of specific pollinating insects in the British Isles.
This orchid likes to grow in deciduous woodland, preferring beech on chalk soil. As it's not a large plant and is easily shaded out, it does not compete well with other vegetation. This may also be a factor as to why the plant is not thriving.
Tests were carried out by scientists at the Jodrell laboratory to extract the DNA of the red helleborine groups from the three locations they inhabit. The reason for doing this was to discover if the plants in these groups were all from one parent, or whether there was any variation. This was particularly important for the group in the Chilterns, as they had been declining rapidly over the years despite careful management.
For the tests, small bits of leaf were taken from each plant and then processed to extract the DNA. Two of the sites in Hampshire and the Cotswolds, had good variation of stock. It was not such good news for the orchids in the Chilterns, these were found to have little variation, which might explain depleting numbers. The future doesn't look bright for this beautiful orchid in the Chilterns. It is hoped that creating a few more open spaces in the woodland where it lives, new plants will appear, thrive and give better variation of stock.
White Helleborine Cephalanthera damasonium
This orchid is mostly found in the east of England, where it likes to grow in woodland. Its favoured habitat is beech woods, where it can been seen in large numbers.
The leaves of this orchid are large and ovate, they are deeply ribbed and grow in pairs up the stem. The leaves merge into leaf-like bracts towards the top of the stem. It's from between these leaf-like bracts that the flower buds emerge.
The plant can grow up to 60cm and bear up to 16 flowers. The flowers are creamy white in colour and resemble small tulips. The flowers do not fully open, but if you look closely you can see a small lip just sticking out on one side. The lip is yellow inside, with a deeper yellow ridge leading inside the flower.
Like many orchids, this orchid is also self-pollinating, although the solitary bee Andrena florea is known to visit these orchids.
Although this orchid is fairly abundant, many have been lost due to woodland clearance. However, this orchid will quickly colonise newly-planted beech woods given the opportunity.
Hybrids
There have been two records, in Hampshire and Sussex, that the white helleborine has crossed with the narrow-leaved helleborine. This is rare as they tend to grow in different sites.
Narrow- or Sword-leaved Helleborine Cephalanthera longfolia
This orchid is the tallest of this group; it can reach up to 160cm. As its name suggests, its leaves are long, narrow and pointed. They grow in pairs up the stem, but stop where the first flower bud appears.
The flowers are held out from the stem and are pure white in colour. There can be as many as 40 flowers on a single stem. The three outer petals are long and point slightly outwards, while the two inner petals are shorter and blunt, forming a protective covering over the lip. The lip is orange, with three ridges on the epichile1, which help guide pollinators to the centre of the flower. This orchid is pollinated by species of solitary bees Lasioglossum smeathmannellum and Lasioglossum fulvicornis. Its seed production is poor as it cannot self-pollinate; this is due to the rostellum2 being large and preventing the fertile stigmas reaching the pollen from the stamens.
This orchid likes a wide range of habitats, from beech, ash and oak forests to acid soil and even between limestone paving. It inhabits small areas all over the British Isles. Although very rare, this orchid does have one success story. In the Meon Valley in Hampshire, recent surveys have shown that flowering plants have increased dramatically in the last ten years. In 1997 there were 794 flowering plants, but by 2007 the numbers had risen to 3,421.