Mystery plants at Loch nan Eun
Early in May 2020, Anne Nicoll of Nedd told us about some botanical curiosities she and Grant had found at the edge of the parking area by Loch nan Eun on the road east from Lochinver (NC109238). We visited the site on 13th May and located them in some boggy ground on the eastern side of the parking area (photo 1).
Most conspicuous were four plants of the North American species known as American skunk-cabbage Lysichiton americanus, a relative of Lords-and-Ladies or Cuckoo-pint Arum maculatum, which is a familiar plant in England, Wales, and south and east Scotland. American skunk-cabbage (photo 2) is a very impressive plant, first introduced to the British Isles from Western North America in 1901 for planting in swampy ground and by 1947 it had escaped and been found in the wild. It flowers early in the spring, producing large yellow spathes wrapped round greenish spadices, succeeded later by clumps of bright green upright leaves up to a metre tall. It is now recognized as a potentially serious invasive alien. There is a large stand in marshy ground just above the shoreline at the bottom of Inverpark in Lochinver (NC0822) and these few plants are presumably a throw-out by a local gardener who, rightly, suspects its ambitions.
Not far away was another non-native species with lovely reddish-orange stems and flowers, which we recognized as one of the spurges. It does not appear in the latest edition of the New Flora of the British Isles (Stace 2019), but was tracked down in horticultural literature as the cultivar Fireglow of a Himalayan spurge Euphorbia griffithii (photos 3-4). This is recorded as a ‘garden escape persistent or established on a roadside’ at a locality thought to be in Lancashire, but has never before been found locally. Thankfully it would not appear to have significant potential for nuisance, and it will be interesting to see if survives in native vegetation dominated by bog-myrtle Myrica gale.
Whilst we were casting around for these exotics, we noticed some very elegant examples of a native horsetail at the near edge of the parking area, which we did not immediately recognise. They were cone-bearing shoots, with large brown chaffy stem sheaths and just the start of rings of leafy branches below the cones. A closer look, using the magnificent new book on ferns and their relatives by James Merryweather (see below), revealed them to be the fertile stems of wood horsetail Equisetum sylvaticum, which is readily identified later in the year by its umbrella-like whorls of delicately- branched stems.
Some horsetails, such as the common field horsetail E. arvense, bear their cones on fertile stems which lack chlorophyll, followed by the green sterile ones, but wood horsetail is more variable, often developing green branches after the cones have ripened, shed their spores and died (photos 5-7). We had not previously come across it at this early stage and David Haines has been photographing the transition.
Merryweather, J., 2020. Britain’s Ferns. A field guide to the clubmosses, quillworts, horsetails and ferns of Great Britain and Ireland. Oxford; Princeton University Press
Ian Evans and Gwen Richards