Coed y Ciliau
Also within
Habitats
Description
Description The once extensive west-facing oakwoods of the steeply sloping sides of the Gwenwst and Dulas valleys have in recent years been largely cleared to be replanted with conifers, or converted to pasture. This site remains as the last substantial fragment displaying, it is believed, most of the range of variation once present in the formerly more extensive woodlands. As an example of an acidic sessile oakwood, it is particularly notable for its species-rich wet flushes. Much of the oak is of coppice origin, through scattered maiden or singled trees occur. The drier freely drained slopes support a ground flora of bilberry Vaccinium myrtillus and wavy hair-grass Deschampsia flexuosa amongst moss lawns dominated by Dicranum and Rhytidiadelphus species. Large wet flushes are present where ash and alder add diversity to the canopy. A wide range of herbs occurs, including primrose Primula vulgaris, sanicle Sanicula europaea, common valerian Valeriana officinalis, dog's mercury Mercurialis perennis and enchanter's-nightshade Circaea lutetiana. These grow amongst sedges and grasses normally scarce in steeply sloping sessile oak woods, such as false brome Brachypodium sylvaticum and smooth-stalked sedge Carex laevigata. A rich lichen flora is recorded from the trees, including the rare tree lungwort Lobaria pulmonaria and other species characteristic of ancient woodland, such as Phyllopsora rosei, Bacidia biatorina and Dimerella lutea. No systematic survey of the animal-life of the wood has yet been undertaken, but a good population of pied flycatchers is present amongst the more widespread and common woodland bird species.
Species mentioned
Show the 13 species mentioned in the description, with red-list status| English name search for this in other sites |
Latin name search with Google |
IUCN / Red List | Type | Family |
|---|---|---|---|---|
| wood false brome | Brachypodium sylvaticum | LC | grass | poaceae |
| wavy hair grass | Deschampsia flexuosa | Not listed in GB list | grass | poaceae |
| enchanter's nightshade | Circaea lutetiana | LC | herb | onagraceae |
| dog's mercury | Mercurialis perennis | LC | herb | euphorbiaceae |
| primrose | Primula vulgaris | LC | herb | primulaceae |
| sanicle | Sanicula europaea | LC | herb | apiaceae |
| common valerian | Valeriana officinalis | LC | herb | caprifoliaceae |
| lichen | Bacidia biatorina | LC | lichen | ramalinaceae |
| orange dimple lichen | Dimerella lutea | Not listed in GB list | lichen | no common name |
| tree lungwort | Lobaria pulmonaria | LC | lichen | no common name |
| lichen | Phyllopsora rosei | LC | lichen | ramalinaceae |
| smooth stalked sedge | Carex laevigata | LC | sedge | cyperaceae |
| billberry | Vaccinium myrtillus | LC | shrub | ericaceae |
Insects 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 |
| Chequered skipper Carterocephalus palaemon |
Endangered | Brachypodium sylvaticum |
| Duke of Burgundy Hamearis lucina |
Endangered | Primula vulgaris |
| Broom moth Ceramica pisi |
Vulnerable | Vaccinium myrtillus |
| Mottled umber Erannis defoliaria |
Vulnerable | Vaccinium myrtillus |
| Grayling Hipparchia semele |
Vulnerable | Brachypodium sylvaticum |
| 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 | Vaccinium myrtillus |
| Rosy marsh moth Coenophila subrosea |
Near Threatened | Vaccinium myrtillus |
| The Silurian Eriopygodes imbecilla |
Near Threatened | Vaccinium myrtillus |
| Wall Lasiommata megera |
Near Threatened | Brachypodium sylvaticum |
| 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.