Caeau Pen-y-coed
Habitats
Geology & landscape
Geological Period: Silurian
Description
Description Caeau Pen-y-coed is of special interest for its unimproved neutral grassland which is associated with areas of acidic grassland and other habitats including mature woodland, scrub and bracken. Caeau Pen-y-coed comprises of a series of 11 contiguous fields occupying the northern flank of a low hill approximately 1 km to the south east of the centre of Llangollen. The site ranges from 110 m to 200 m in altitude and overlooks the town, with urban housing to the north and the mixed coniferous and broadleaved woodland of Pen-y-coed to the south. The solid geology of the site consists of calcareous shales (Silurian Period) that are overlain by well-drained slightly to very stony brown soils. These circumneutral brown soils support areas of the now uncommon crested dog’s-tail Cynosurus cristatus common knapweed Centaurea nigra grassland, meadow vetchling Lathyrus pratensis sub-community. This community was the major grassland type of traditionally managed hay meadows and pastures throughout the lowlands of Britain. The grasses most commonly found are red fescue Festuca rubra, crested dog’s tail, and common bent Agrostis capillaris along with sweet vernal grass Anthoxanthum odoratum, cock’s-foot Dactylis glomerata and Yorkshire-fog Holcus lanatus. Herbs present in the sward include those indicative of unimproved grassland such as common bird’s-foot trefoil Lotus corniculatus, rough hawkbit Leontodon hispidus and meadow vetchling. The site also supports areas of dry acidic (calcifugous) grassland and include small stands of the nationally uncommon bitter-vetch Lathyrus montanus, betony Stachys officinalis sub-community of sheep’s fescue Festuca ovina, common bent, heath bedstraw Galium saxatile grassland. These are floristically similar to the adjacent areas of neutral grassland sharing several of its more prominent grasses and herbs, among them common bent, sweet vernal-grass, common knapweed and common bird’s-foot trefoil, and are distinguished primarily by the presence and often abundance of sheep’s fescue Festuca ovina, devils-bit scabious Succisa pratensis and bitter-vetch. Small areas of the more mesotrophic Yorkshire-fog -white clover Trifolium repens sub-community of this grassland are also present as well as patches dominated by wavy hair-grass Deschampsia flexuosa, with frequent to abundant heath bedstraw and bilberry Vaccinium myrtillus. Caeau Pen-y-Coed includes associated stands of mature woodland, scrub and bracken which form an integral part of the site and add to the structural and ecological diversity of the habitat mosaic.
Species mentioned
Show the 18 species mentioned in the description, with red-list statusInsects to look out for
These moths, butterflies and beetles are known to feed on plants recorded at this site, and carry a notable UK conservation status — but a host-plant being present doesn't mean the insect has actually been recorded here. Treat this as "worth watching for," not a confirmed sighting.
| Species | Status | Via host-plant |
|---|---|---|
| Speckled footman Coscinia cribraria |
Critically Endangered | Vaccinium myrtillus |
| Black-veined moth Siona lineata |
Critically Endangered | Centaurea nigra, Lotus corniculatus |
| New forest Zygaena viciae |
Critically Endangered | Lathyrus pratensis, Lotus corniculatus |
| Straw belle Aspitates gilvaria |
Endangered | Lotus corniculatus |
| Wood white Leptidea sinapis |
Endangered | Lathyrus pratensis, Lotus corniculatus |
| Slender scotch Zygaena loti |
Endangered | Lotus corniculatus |
| Mouse moth Amphipyra tragopoginis |
Vulnerable | Lotus corniculatus |
| Broom moth Ceramica pisi |
Vulnerable | Vaccinium myrtillus |
| Mottled umber Erannis defoliaria |
Vulnerable | Vaccinium myrtillus |
| Dingy skipper Erynnis tages |
Vulnerable | Lotus corniculatus |
| Marsh fritillary Euphydryas aurinia |
Vulnerable | Succisa pratensis |
| Satyr pug Eupithecia satyrata |
Vulnerable | Centaurea spp., Galium spp. |
| Garden dart Euxoa nigricans |
Vulnerable | Trifolium spp. |
| Grayling Hipparchia semele |
Vulnerable | Festuca ovina, Festuca rubra |
| Bedstraw hawk-moth Hyles gallii |
Vulnerable | Galium spp. |
| Silver studded blue Plebejus argus |
Vulnerable | Lotus corniculatus |
| Early moth Theria primaria |
Vulnerable | Vaccinium myrtillus |
| Pale eggar Trichiura crataegi |
Vulnerable | Vaccinium myrtillus |
| Flounced chestnut Agrochola helvola |
Near Threatened | Vaccinium myrtillus |
| Beaded chestnut Agrochola lychnidis |
Near Threatened | Trifolium spp., Vaccinium myrtillus |
| Large nutmeg Apamea anceps |
Near Threatened | Dactylis glomerata |
| Latticed heath Chiasmia clathrata |
Near Threatened | Lathyrus pratensis, Trifolium repens, Trifolium spp. |
| Small heath Coenonympha pamphilus |
Near Threatened | Agrostis spp., Cynosurus cristatus, Festuca spp. |
| Rosy marsh moth Coenophila subrosea |
Near Threatened | Vaccinium myrtillus |
| The Silurian Eriopygodes imbecilla |
Near Threatened | Galium saxatile, Vaccinium myrtillus |
| Autumnal rustic Eugnorisma glareosa |
Near Threatened | Festuca ovina, Galium spp. |
| Grey pug Eupithecia subfuscata |
Near Threatened | Centaurea spp. |
| Silver-spotted skipper Hesperia comma |
Near Threatened | Festuca ovina |
| Scarce forester Jordanita globulariae |
Near Threatened | Centaurea nigra |
| Wall Lasiommata megera |
Near Threatened | Agrostis spp., Dactylis glomerata, Holcus lanatus |
| Rosy minor Litoligia literosa |
Near Threatened | Dactylis glomerata, Festuca ovina |
| Dark-barred twin-spot carpet Xanthorhoe ferrugata |
Near Threatened | Galium spp. |
| Scotch burnet Zygaena exulans |
Near Threatened | Vaccinium myrtillus |
Host-plant data: Cook et al. (2025), Traits data for the butterflies and macro-moths of Great Britain and Ireland, 2024, UK Centre for Ecology & Hydrology / Butterfly Conservation; and Padovani et al. (2020), Database of Insects and their Food Plants (DBIF), UK Centre for Ecology & Hydrology (both Open Government Licence). Contains data supplied by UK Centre for Ecology & Hydrology.
Plant communities
W20 — Montane scrub
Salix lapponum-Luzula sylvatica scrub
Matches 8 species from the description above: Agrostis capillaris, Anthoxanthum odoratum, Deschampsia flexuosa, Festuca ovina, Festuca rubra, Galium saxatile, Succisa pratensis, Vaccinium myrtillus
Show 107 indicator speciesSalix arbuscula, Salix cinerea, Salix lapponum, Salix myrsinites, Salix phylicifolia, Salix reticulata, Empetrum nigrum, Calluna vulgaris, Salix lanata, Vaccinium myrtillus, Vaccinium uliginosum, Carex atrata, Carex bigelowii, Carex binervis, Carex flacca, Luzula multiflora, Luzula sylvatica, Huperzia selago, Selaginella selaginoides, Aulacomnium palustre, Mnium hornum, Philonotis fontana, Plagiomnium undulatum, Rhizomnium punctatum, Dicranum bonjeanii, Dicranum majus, Dicranum scoparium, Fissidens adianthoides, Racomitrium lanuginosum, Calliergonell cuspidatum, Ctenidium molluscum, Hylocomium splendens, Hypnum callichroum, Hypnum cupressiforme, Palustriella commutatum, Plagiothecium denticulatum, Plagiothecium undulatum, Pleurozium schreberi, Ptilium crista-castrensis, Rhytidiadelphus loreus, Rhytidiadelphus squarrosus, Rhytidiadelphus triquetrus, Sanionia uncinata, Scorpidium revolvens, Thuidium tamariscinum, Atrichum undulatum, Polytrichastrum alpinum, Sphagnum capillifolium, Sphagnum fallax, Sphagnum girgensohnii, Sphagnum palustre, Sphagnum russowii, Sphagnum squarrosum, Sphagnum subnitens, Sphagnum teres, Barbilophozia barbata, Chiloscyphus polyanthos, Diplophyllum albicans, Lophocolea bidentata, Plagiochila porelloides, Ptilidium ciliare, Scapania undulata, Cladonia squamosa, Peltigera canina, Angelica sylvestris, Caltha palustris, Hieraclium spp., Saussurea alpina, Solidago virgaurea, Campanula rotundifolia, Succisa pratensis, Valeriana officinalis, Rhodiola rosea, Vaccinium vitis-idaea, Thymus praecox, Epilobium anagallidifolium, Dactylorhiza viridis, Euphrasia officinalis, Rhinanthus minor, Oxalis acetosella, Oxyria digyna, Polygonum viviparum, Rumex acetosa, Anemone nemorosa, Ranunculus acris, Thalictrum alpinum, Alchemilla alpina, Alchemilla glabra, Filipendula ulmaria, Geum rivale, Galium boreale, Galium saxatile, Saxifraga aizoides, Saxifraga hypnoides, Saxifraga oppositifolia, Saxifraga stellaris, Viola riviniana, Agrostis canina, Agrostis capillaris, Anthoxanthum odoratum, Deschampsia cespitosa, Deschampsia flexuosa, Festuca ovina, Festuca rubra, Nardus stricta, Dryopteris dilatata, Phegopteris connectilis
W25 — Bracken scrub
Pteridium aquilinum-Rubus fruticosus underscrub
Matches 6 species from the description above: Agrostis capillaris, Anthoxanthum odoratum, Dactylis glomerata, Festuca rubra, Galium saxatile, Holcus lanatus
Show 53 indicator speciesHedera helix, Acer pseudoplatanus, Fagus sylvatica, Quercus robur, Fraxinus excelsior, Sambucus nigra, Ulex europaeus, Crataegus monogyna, Prunus spinosa, Luzula multiflora, Mnium hornum, Brachythecium rutabulum, Kindbergia praelonga, Angelica sylvestris, Conopodium majus, Heracleum sphondylium, Arum maculatum, Cirsium arvense, Lonicera periclymenum, Silene dioica, Stellaria holostea, Mercurialis perennis, Geranium robertianum, Glechoma hederacea, Teucrium scorodonia, Hyacinthoides non-scripta, Chamerion angustifolium, Circaea lutetiana, Digitalis purpurea, Rumex acetosa, Anemone nemorosa, Ficaria verna, Potentilla erecta, Rosa arvensis, Rosa canina, Rubus fruticosus agg., Rubus idaeus, Galium aparine, Galium mollugo sens.lat., Galium saxatile, Urtica dioica, Viola riviniana, Agrostis capillaris, Anthoxanthum odoratum, Arrhenatherum elatius, Dactylis glomerata, Festuca rubra, Holcus lanatus, Holcus mollis, Poa trivialis, Pteridium aquilinum, Dryopteris dilatata, Dryopteris filix-mas
W22 — Hedgerow scrub, Mixed scrub
Prunus spinosa-Rubus fruticosus scrub
Matches 4 species from the description above: Agrostis capillaris, Dactylis glomerata, Festuca rubra, Holcus lanatus
Show 49 indicator speciesHedera helix, Acer campestre, Corylus avellana, Ulex europaeus, Prunus spinosa, Plagiomnium undulatum, Brachythecium rutabulum, Eurhynchium striatum, Kindbergia praelonga, Thuidium tamariscinum, Atrichum undulatum, Lophocolea bidentata, Achillea millefolium, Cardamine flexuosa, Lonicera periclymenum, Moehringia trinervia, Silene dioica, Silene uniflora, Stellaria media agg., Mercurialis perennis, Geranium robertianum, Stachys sylvatica, Teucrium scorodonia, Hyacinthoides non-scripta, Oxalis acetosella, Digitalis purpurea, Plantago lanceolata, Veronica chamaedrys, Armeria maritima, Rumex acetosa, Filipendula ulmaria, Geum urbanum, Rosa canina, Rubus fruticosus agg., Rubus idaeus, Galium aparine, Urtica dioica, Viola riviniana, Agrostis capillaris, Brachypodium sylvaticum, Dactylis glomerata, Festuca rubra, Holcus lanatus, Holcus mollis, Poa trivialis, Asplenium scolopendrium, Pteridium aquilinum, Dryopteris borreri, Dryopteris filix-mas
W21 — Hedgerow scrub, Mixed scrub
Crataegus monogyna-Hedera helix scrub
Matches 2 species from the description above: Dactylis glomerata, Holcus lanatus
Show 81 indicator speciesHedera helix, Salix cinerea, Acer pseudoplatanus, Ilex aquifolium, Betula pendula, Corylus avellana, Fagus sylvatica, Quercus robur, Fraxinus excelsior, Malus sylvestris, Sorbus aria, Taxus baccata, Ulmus glabra, Ulmus procera, Sambucus nigra, Viburnum lantana, Euonymus europaeus, Cornus sanguinea, Juniperus communis, Ligustrum vulgare, Clematis vitalba, Rhamnus cathartica, Crataegus laevigata, Crataegus monogyna, Prunus spinosa, Juncus effusus, Plagiomnium undulatum, Brachythecium rutabulum, Kindbergia praelonga, Rhynchostegium confertum, Tamus communis, Heracleum sphondylium, Torilis japonica, Arum maculatum, Arctium minus, Cirsium arvense, Lonicera periclymenum, Moehringia trinervia, Silene dioica, Stellaria graminea, Stellaria holostea, Stellaria media agg., Calystegia sepium, Mercurialis perennis, Geranium robertianum, Iris foetidissima, Glechoma hederacea, Lamium purpureum, Origanum vulgare, Stachys sylvatica, Teucrium scorodonia, Allium ursinum, Hyacinthoides non-scripta, Circaea lutetiana, Rumex sanguineus, Anemone nemorosa, Ranunculus repens, Fragaria vesca, Geum urbanum, Potentilla sterilis, Poterium sanguisorba, Rosa arvensis, Rosa canina, Rubia peregrina, Rubus fruticosus agg., Galium aparine, Urtica dioica, Viola riviniana, Anisantha sterilis, Arrhenatherum elatius, Brachypodium pinnatum, Brachypodium sylvaticum, Bromopsis erecta, Dactylis glomerata, Elytrigia repens, Holcus lanatus, Holcus mollis, Poa trivialis, Asplenium scolopendrium, Pteridium aquilinum, Dryopteris filix-mas