Achmelvich: some puzzling orchids
On the evening of 14th July 2022, we had arranged to count the common pipistrelle colony at the Yates’s property on the road to Achmelvich. With time to spare, we thought that we might check out a large orchid that Alson Yates had discovered earlier, not far from the northern beach (NC0525).
It was not difficult to find the plant from her instructions, on a rocky bank in the company of globeflower (photo 1). The inflorescence was large, often a sign of hybrid origin, and the flowers were dark and well-marked (photo 2).
More difficult was putting a name to it, so Gwen took some photos (in failing light) and we collected one floret, to compare with those of possible parents. We noted, incidentally, that the flowers had a faint, pleasant scent.
Assigning a name
Not far away there were some fragrant-orchids, a possible parent, which Gwen also photographed (photo 3), and from which we also collected a floret. The dark, well-marked flowers of the possible hybrid suggested that the other parent might be northern marsh-orchid, which certainly grows nearby. So, next day, Ian photographed the two florets collected, together with a third from the latter species (photo 4).
We have since compared the photographs with the excellent illustrations in the recent book on Britain’s Orchids (Cole and Waller, 2020, p.259). The putative hybrid is quite a good match for x Dactylodenia varia, whose parents are heath fragrant-orchid and northern marsh-orchid. It has only been recorded sparsely from the area in which the two parents overlap, and never this far north.
A possible complication is that marsh fragrant-orchid is now known to occur in Assynt, having been found in 2005 near Ardvreck Castle, and some of the specimens at Achmelvich could just possibly be this other species. The hybrid between it and northern marsh-orchid is even rarer. We shall have to return this coming summer and take a closer look at all of them.
Ian M. Evans and Gwen Richards
If you want to learn more about orchids, here is a link to Ian’s talk on Orchids in West Sutherland in February 2022