In Dartmoor National Park.
Area: 4.82 hectares.
Description and Reasons for Notification:
This wet, sloping field contains the most extensive single area known in Devon of a type of wetland vegetation found predominantly in southwestern Britain. It is also notable for unusually large stands of bog asphodel Narthecium ossifragum, and for the presence of several uncommon plant and insect species.
The field, which faces north-west, lies on the northern edge of Dartmoor on metamorphosed Carboniferous shale. Its clayey soils are for the most part heavily flushed with water arising from numerous springs and from a small stream coming off the Moor. The site has traditionally been grazed by ponies.
A wide variety of different plant communities are present, two being of particular interest. The first is found where water flows over the surface of the ground for much of the year, and is characterised by abundant marsh St. John’s wort Hypericum elodes with bog pondweed Potamogeton polygonifolius. Not only is this community particularly extensive within the site, but it is also remarkably well- developed, supporting an unusually wide variety of plants. Bog pimpernel Anagallis tenella grows here in profusion, together with species such as marsh pennywort Hydrocotyle vulgaris and lesser spearwort Ranunculus flammula. Many-stemmed spike-rush Eleocharis multicaulis and marsh lousewort Pedicularis palustris are frequent, the latter being only local in Devon.
The second community occurs on slightly drier ground, and is characterized by purple moor-grass Molinia caerulea and heath tormentil Potentilla erecta it is of interest for the extensive stands of bog asphodel present. Associated plants include cross-leaved heath Erica tetralix, star sedge Carex echinata, heath-spotted orchid Dactylorhiza maculata, and frequent lesser skull-cap Scutellaria minor and ivy-leaved bell-flower Wahlenbergia hederacea.
Other plant communities present include short swards dominated by sedges, principally carnation sedge Carex flacca, yellow sedge C. demissa and common sedge C. nigra, together with bent grasses Agrostis spp., purple moor-grass, and species such as meadow thistle Cirsium dissectum and devil’s-bit scabious Succisa pratensis. Bog mosses of several species, including Sphagnum auriculatum, the local S. squarrosum and S. fallax, are frequent in places and sometimes hummock-forming, the first usually being found together with round-leaved sundew Drosera rotundifolia and the last with marsh violet Viola palustris.
Elsewhere there are small areas dominated by sharp-flowered rush Juncus acutiflorus, with much greater bird’s-foot trefoil Lotus pedunculatus and wild angelica Angelica sylvestris.
Scattered throughout the flushed slopes are willow Salix spp. bushes, usually with lady fern Athyrium filix-femina at their bases. In addition, but generally of less interest, much of the drier upper slopes support an open oak Quercus robur and ash Fraxinus excelsior woodland, with some ader Alnus glutinosa and alder buckthorn Frangula alnus, and clearings dominated by bracken Pteridium aquilinum. The occasional lemon-scented fern Thelypteris limbosperma near the road is of special note, since this is a very local species in Devon.
The invertebrate fauna of the site is not well known, but does include keeled skimmer dragonfly Orthetrum coerulescens and five-spot burnet moth Zygaena trifolii, both local species found predominantly in south-western Britain.