Achlorophyllous BLH

I discovered this Helleborine on the 27th July 2015 on a return trip to an orchid site. A month earlier a number of Epipactis in bud were found, and I hoped they may be in flower on the second visit. They weren't, but in the hope of finding some actually in flower I searched a wider area and found the `achlorophyllous Helleborine'. As I had been hoping that the other Epipactis were E. leptochila I initially labelled it as such; there were some features they do support that name. Other orchid enthusiasts and experts doubted this due to the other Epipactis plants looking like E. Helleborine. This was borne out when the first flower opened on 2nd August.

The `achlorophyllous Helleborine' was growing on the fringe of a former limestone quarry a few miles south of Cheltenham. It was on ivy covered ground between a mixed deciduous wooded area and a lane. The other E. Helleborine plants also grow on the edge of woodland and lane, or quarry floor.

It is approximately 40cm tall with about 20 flower buds, mainly orientated to one side of the flower spike. The entire plant is a pale butter-yellow, or straw colour, being totally deficient of both chlorophyll and anthocyanin. The only other colour is the small orange stripe on the side of the pollen sacs. The leaves and bracts had withered, perhaps in part due to their redundancy, or the dry weather that had preceeded the finding. The plant presumably obtains all its nutrients and energy from association by cheating on its fungal partner in the rhizome, and possibly ectomycorrhizal fungi in the tree roots. There are other examples of Epipactis lacking chlorophyll. E. helleborine var. monotropoides still produces anthocyanin leading to a straw coloured plant with pale pink tones to the flowers. E. purpurata var. rosea typically has a strikingly large amount of anthocyanin and is in part a bright magenta colour. The nearest other orchid, about 2 metres away, is E. Helleborine var. chlorantha, which also lacks anthocyanins. The whole plant is just green from chlorophyll. This discussion looks at the ways this plant could be both deficient of chlorophyll and anthocyanin, and whether the neighbouring var. chlorantha is related or just a coincidence.