Llanelli Naturalists Newsletter - No. 74 - July 2008
Mike Smith

On entering Gelli Aur Country Park, the visitor travels down an impressive avenue of common lime trees Tilia x europaea.  The lime avenue was probably planted at around the same time the mansion was built in the 1830s.  Dense shade exists under the trees where there is deep leaf litter. It is here that a remarkably unusual orchid can sometimes be found.

Bird's-nest Orchid, Neottia nidus-avis (see photo on front cover), is brown in colour and can be easily overlooked against the leaf litter.  The orchid lacks any significant amount of the green photosynthetic compound, chlorophyll.  Therefore, unable to photosynthesize its own sugars, the orchid has a close ecological relationship with a fungus.  The fungus may gain its energy by breaking down the leaf litter, or could it also be associated with the lime trees?

Bird's Nest Orchid grows at only a few sites in Carmarthenshire although it is more frequent in the beech woods of south east England. The Gelli Aur orchids were first found in the late 1980s but the appearance of flower spikes is erratic as the plants are able to exist, unseen, underground for a number of years.  During May 2008, the Country Park Ranger, Keith Williams found four flower spikes and when visited by Philip Jones, Kath and Richard Pryce on 10th May there were seven spikes (see cover photo).  However, when visited on 19th May, all of the orchids had been nipped off, presumably by browsing fallow deer and only two ‘stumps’ were visible (the surrounding vegetation had also been cropped by grazing, particularly the Wood Sedge Carex sylvatica which is a locally abundant associate).  Nevertheless, more Bird's Nest Orchids may still appear this year.  And why the name Bird's Nest Orchid?  The underground rhizomes resemble a crow's nest.

Two other orchids can also be found under the lime trees: Common Twayblade Listera ovata and Broad-Leaved Helleborine Epipactis helleborine, both of which were seen on 19th May.