Flowering plants and ferns
Ian Evans (March 2010)
1. Introduction. The first observations of flowering plants and ferns in Assynt date back to the visit of James Robertson in 1767, since when they have been studied by generations of botanists. Some 770 species have been recorded in the parish, about 700 of those during the last two decades, and additions are still being made.
Between 1988 and 2000 the flora of Assynt was surveyed and mapped by tetrads (2 x 2 km squares), the first tme this had been done in Highland Scotland. The results of this survey, and also one of the bryophytes of the parish, are contained in the Flora of Assynt (Evans, P.A., Evans, I.M. and Rothero, G.P., 2002). This work runs to 284 pages in A4 format. It contains a Description of Assynt (boundaries, geology, climate, landscape history and vegetation), a 112-page section on the Flowering plants and ferns (history of recording, survey and species account, with distribution maps), and a 78-page section on the Bryophytes. It also has a full bibliography, gazetteer and separate systematic indexes.
2. Highlights. You are referred to the Flora or its authors (see below) if you have any detailed questions, or better still, additions. What follows is a brief account of characteristic and interesting species, to whet your appetite to come and see for yourself. It is arranged by habitat, from the coast to the tops of the hills and is based on the Vegetation section in the Flora. Some species are near their northern British limits in Assynt, and locally noteworthy for that reason.
Coast. Eel-grass Zostera marina, has been found at Drumbeg, but wash-ups suggest it may occur elsewhere. Much of the coast is rocky, with sea spleenwort Asplenium marinum, Scots lovage Ligustrum scoticum, roseroot Sedum rosea and sea campion Silene uniflora on the cliffs, and, occasionally at their foot, hemlock water-dropwort Oenanth crocata and tiny plants of chaffweed Anagallis minima. Cliff-top grassland on the Stoer peninsula has stands of small adder’s-tongue fern Ophioglossum azoricum, and near Nedd the usually montane dwarf willow Salix herbacea grows at about 15m above sea level. Small areas of shingle support greater skullcap Scutellaria galericulata, and in just one well-guarded site, oyster plant Mertensia maritima. On the sand-dunes at Achmelvich are frog orchid Coeloglossum viride and spring squill Scilla verna. The dunes at Clachtoll and Stoer have biting stonecrop Sedum acre and, in one place, the dune form of early marsh-orchid Dactylorhiza incarnata coccinea. Purple milk-vetch Astragalus danicus is also flourishing at Clachtoll. Small estuarine salt-marshes always have sea milk-wort Glaux maritima and occasionally sea aster Aster tripolium and glasswort Salicornia europaea.
Woodland and scrub. Most of Assynt’s woodland is in a strip within 5km of the coast, with outliers elsewhere, and much is dominated by downy birch and rowan. Richer areas, stretching from Baddidarach to Achmelvich and Culkein Drumbeg to Unapool, have frequent oak, hazel and aspen, with occasional wych elm and bird cherry. Bryophyte-rich boulder scree abounds, often with Wilson’s filmy-fern Hymenophyllum wilsonii. Other ferns include hay-scented buckler-fern Dryopteris aemula, northern buckler-fern D. expansa and the delicate oak fern Gynnocarpium dryopteris. Base-rich areas of soil support sheets of ramsons Allium ursinum and sweet woodruff Galium odoratum.. Specialities include broad-leaved and narrow-leaved helleborine orchids, Epipactis helleborine and Cephalanthera longifolia at Achmelvich, with the only local stand of bird’s-nest orchid Neottia nidus-avis not far away.
Heath, mire and crags. Much of this habitat in Assynt has been modified by peat-digging, burning and grazing. Remote areas with stands of prostrate juniper Juniperus communis nana and bearberry Arctostaphylos uva-ursi show what more of it may once have been like. Black bog-rush Schoenus nigricans often dominates mires, accompanied by white beak-sedge Rhynchospora alba, and the sticky leaves of great and round-leaved sundew Drosera anglica and D. rotundifolia catch the eye. Rarer are stands of fen-sedge Cladium mariscus and greater tussock sedge Carex paniculata. Base-rich flushes have broad-leaved cotton-grass Eriophorum latifolium and pale butterwort Pinguicula lusitanica and, rarely, rough horsetail Equisetum hyemale or lapland orchid Dactylorhiza lapponica. Crags have scattered populations of forked-leaved spleenwort Asplenium septentrionale and more frequently, not far from the sea, wood bitter-vetch Vicia orobus. Soily scree at their feet is a good place to look for pyramidal bugle Ajuga pyramidalis, a local speciality.
Lochs, lochans, rivers and burns. With some 680 lochs, mostly on gneiss, Assynt is not lacking aquatics. Nutrient-poor lochs have quillworts Isoetes spp., water lobelia Lobelia urens, bog-bean Menyanthes trifoliata and floating bur-reed Sparganium angustifolium. Slightly richer ones have white water-lily Nymphaea alba, common club-rush Schoenoplectus lacustris, with marsh cinquefoil Potentilla palustris or bog hair-grass Deschampsia setacea on the margins. The richest have pillwort Pilularia globulifera, amphibious bistort Persicaria amphibia or mare’s-tail Hippuris vulgaris. Least water-lily Nuphar pumila has recently been found in Loch Beannach. Faster-flowing stretches of burns have alternate water-milfoil Myriophyllum alterniflorum and the few slow-flowing rivers branched bur-reed Sparganium erectum and, rarely, water sedge Carex aquatilis.
Limestone. The limestone running through the east of Assynt and the associated Fucoid Beds have a very rich flora. Brittle bladder-fern Cystopteris fragilis is frequent on the Fucoid Beds, with occasional shade horsetail Equisetum pratense. Species characteristic of the limestone proper include mountain avens Dryas octopetala, limestone bedstraw Galium sterneri, alpine bistort Persicaria vivipara and twayblade orchid Listera ovata. Crevices shelter green spleenwort Asplenium viride and holly fern Polystichum lonchitis and ledges free from grazing have dark-red helleborine Epipactis atrorubens. A characteristic shrub is whortle-leaved willow Salix myrsinites. The higher limestone outcrops and flushes behind Inchnadamph have specialities such as alpine cinquefoil Potentilla crantzii and Scottish asphodel Tofieldia pusilla.
Upland (over 300m.). Ungrazed ledges on the hills can have very lush vegetation, including globe-flower Trollius europaeus, roseroot Sedum rosea and purple saxifrage Saxifraga oppositifolia, with, in wetter places, mountain sorrel Oxyria digyna. Dwarf shrub heath at the base of the hills may have scattered dwarf cornel Cornus suecicus and cloudberry Rubus chamaemorus. The vegetation on the tops can be species-poor, and dominated by woolly hair-moss Racomitrium lanuginosum, but elsewhere in broken ground there are carpets of arctic bearberry Arctostaphylos alpinus and dwarf willow Salix herbacea with, less commonly, mountain azalea Loiseleuria procumbens and dwarf cudweed Gnaphalium supinum. On the lower slopes of Canisp there is a huge stand of yellow cypress club-moss Diphasiastrum issleri and a smaller one of interrupted club-moss Lycopodium annotinum. The summit ridge of Conival, our highest hill, has other montane specialities such as arctic mouse-ear Cerastium arcticum, alpine saxifrage Saxifraga nivalis and sibbaldia Sibbaldia procumbens, but they are not easy to find.
Man-made habitats. Parts of the Assynt landscape have been modified by man over many thousands of years, but such areas may still of be considerable botanical interest. Grassland is often heavily grazed, but can have good populations of species such as greater and lesser butterfly-orchids Platanthera chlorantha and P. bifolia. Roadsides now have salt-tolerant species such as lesser sea-spurrey Spergularia marina and are our only sites for the locally rare harebell Campanula rotundifolia. On roadsides east of Quinag are large populations of field and autumn gentians Gentianella campestris and G. amarella septentrionalis. In some years large spikes of the hybrid between heath spotted and northern marsh orchids Dactylorhiza x formosa are conspicuous on roadsides. Around Lochinver perennial ‘weeds’ include common figwort Scrophularia nodosa and feverfew Tanacetum parthenium, with occasional ‘exotics’ like viper’s-bugloss Echium vulgare. Cultivated ground is now rare in Assynt, but can harbour occasional plants of corn marigold Chrysanthemum segetum, various fumitories Fumaria spp. and the rarer deadnettles Lamium spp. Well-established escapes from cultivation include a bewildering variety of mints Mentha spp. and monkey-flowers Mimulus spp.
3. Further information. The Flora mentioned above has details of all the plants known to have occurred in Assynt up to the end of 2000, but a number of new species have been recorded since publication. Ian Evans would very much like to hear about any interesting plants you come across and may be contacted at: Calltuinn, Nedd, Drumbeg by Lairg, Sutherland IV27 4NN (01571.833241; or email firstname.lastname@example.org).
For an excellent illustrated account of the flowers of Assynt and neighbouring areas we recommend Wild Flowers of the North Highlands of Scotland by Ken Butler and Ken Crossan, published by Birlinn in 2009.