Orchid hunting at Achmelvich (part 2)
In a previous article we described orchid hunting along the Achmelvich road and at Ardroe. On the first day mentioned, 28thMay 2020, we carried on to the machair beside the back track at Achmelvich. The area between the track and the water-lily lochan (NC061251) is a favourite place for us in spring and early summer (photo 1) and this year its wild flowers have been exceptional.
First to catch our attention were early purple orchids Orchis mascula, whose loose-flowered spikes occur in a variety of shades from pink through to a darker reddish-purple (photos 2-3), and are sometimes bi-coloured. This is a plant of base-rich grassland, both coastal and inland on the limestone, with occasional outliers elsewhere.
Closer to the ground were the deep-blue flattened flowers of common milkwort Polygala vulgaris (photo 4), which is locally much less common than heath milkwort P. serpyllifolia. It is again a plant of base-rich grassland, but with a good scatter of records on the gneiss, often in the vicinity of ultramafic dykes. Apart from a rather subtle difference in the shade of blue, heath milkwort may be recognised by its opposite lower leaves (those of common milkwort being alternate) and its preference for acid moorland. Both species have colour varieties, ranging from purple to pink or white.
We paid our annual respects to spring squill Scilla verna (photos 5-6), at one of only two local sites (the other is not far away, on the seaward edge of the Achmelvich campsite). This lovely, if tiny, relative of the bluebell Hyacinthoides non-scriptus is frequent along the north coast of Sutherland, but it next appears to the south in mainland Scotland on the Mull of Kintyre.
A further plant that caught our attention on this visit was mountain everlasting Antennaria dioica. Although widespread in dry habitats in Assynt, its two forms are rarely so well displayed as they were on this occasion. As the specific name indicates (dioecious is having the two sexes on separate plants), it has female plants with narrow, usually white-flowered heads, and male plants with broad, often pink-flowered heads (photos 7-9).
We returned to this area on 14th June 2020. On our way up the track we were admiring large patches of bird’s-foot trefoil Lotus corniculatus (photo 10), a widespread member of the pea family which is a colourful component of our coastal and other grasslands, especially when its yellow flowers are intermixed with orange ones, hence the vernacular name of bacon andeggs. Another member of the same family, but more exclusively maritime, is kidney vetch Anthyllis vulneraria, with woolly calyces, which was flowering in rocky areas alongside the track (photo 11).
The spring squill had finished flowering and become virtually invisible, but other orchids were apparent. Conspicuous were the deep rose-purple spikes of northern marsh-orchid Dactylorhiza purpurella (photo 12), and, much less showy, the greenish ones of frog orchid Coeloglossum viride (photo 13). Amongst them, however, we found just a few plants of a much rarer plant, the brick-red spikes of the coastal sub-species of early marsh-orchid D. incarnata coccinea (photos 14-15). Achmelvich is the only place in Assynt where this is regularly seen, although it was noted at Clachtoll and Stoer in the 1990s.
Walking back from the lochan to the track, we had another pleasant surprise, albeit rather less obvious than the orchids. Covering an area of perhaps 10m x 5m in the short grassland was a substantial population of adder’s-tongue fern Ophioglossum vulgatum, with bright green fronds bearing the ‘tongues’ of developing sporangia (photo16). This occurs elsewhere in the cliff-top grasslands at Achmelvich, but had not previously been noted at this particular spot.
Our last port of call, on the way back to the carpark, was the only known stand of bulbous buttercup Ranunculus bulbosus in Assynt. It may be so rare because of catastrophic blow-outs that occurred on this site in the mid-20th century and the subsequent, successful, restoration of the ground. It grows along the seaward side of a short stretch of the trackside fence (photo 18), where its cup-shaped flowers with down-turned sepals (photos 19-20) may be found by careful searching in early summer. Its leaves differ subtly from those of the abundant meadow buttercups Ranunculus acris which surround them. Although, once again, common along the coast of north Sutherland, it is inexplicably absent from the west coast south from Assynt to Ardnamurchan, opposite Skye.
The sympathetic grazing regime adopted by local crofters has once again allowed the Achmelvich machair to display its diverse and colourful range of wild flowers, several confined to this one small area of the parish.
Ian M. Evans and Gwen Richards
We would like to thank Bill Badger for a couple of photos taken later, on 25th June.