Pentwyn Farm Grasslands, Penallt
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Geology & landscape
Rock Type: Sandstone
Description
Description Pentwyn Farm Grasslands are situated on the edge of the Penallt village, 4 km south-east of Monmouth. The grasslands lie at an altitude of 120-200 m and have varying aspects (the majority of the site slopes moderately to the south but two of the fields face north and south-east respectively). The underlying geology is Lower Red Sandstone and the soils are classified as brown earths of the Milford and Eardiston I associations. This site supports one of the largest areas of a traditionally managed, unimproved neutral grassland in Gwent, of a community type that is declining in the British Isles. The majority of the site supports grassland of the common knapweed-crested dog’s-tail Centaurea nigra – Cynosurus cristatus, and meadow vetchling sub-community Lathyrus pratensis. The species composition is similar throughout the site with key indicator species, common knapweed, crested dog’s-tail and red clover Trifolium pratense all frequent but with common bird’s-foot-trefoil Lotus corniculatus rather patchily distributed. The most frequent grasses are common bent Agrostis capillaris, sweet vernal grass Anthoxanthum odoratum, red fescue Festuca rubra with crested dog’s-tail Cynosurus cristatus and cock’s-foot Dactylis glomerata common at low cover. The site also supports one of the two largest populations of green-winged orchid Anacamptis morio in Gwent, a species which is becoming uncommon in the county, as well as nationally. Remarks: The site lies within the Wye Valley Area of Outstanding Natural Beauty.
Species mentioned
Show the 10 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 |
|---|---|---|---|---|
| common bent | Agrostis capillaris | LC | grass | poaceae |
| sweet vernal grass | Anthoxanthum odoratum | LC | grass | poaceae |
| crested dog's tail | Cynosurus cristatus | LC | grass | poaceae |
| cock's foot | Dactylis glomerata | LC | grass | poaceae |
| red fescue | Festuca rubra | LC | grass | poaceae |
| green-winged orchid | Anacamptis morio | NT | herb | orchidaceae |
| black knapweed | Centaurea nigra | LC | herb | asteraceae |
| meadow vetchling | Lathyrus pratensis | LC | herb | fabaceae |
| birdsfoot trefoil | Lotus corniculatus | LC | herb | fabaceae |
| red clover | Trifolium pratense | LC | herb | fabaceae |
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 |
|---|---|---|
| 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 |
| Dingy skipper Erynnis tages |
Vulnerable | Lotus corniculatus |
| Satyr pug Eupithecia satyrata |
Vulnerable | Centaurea spp. |
| Garden dart Euxoa nigricans |
Vulnerable | Trifolium spp. |
| Grayling Hipparchia semele |
Vulnerable | Festuca rubra |
| Silver studded blue Plebejus argus |
Vulnerable | Lotus corniculatus |
| Beaded chestnut Agrochola lychnidis |
Near Threatened | Trifolium spp. |
| Large nutmeg Apamea anceps |
Near Threatened | Dactylis glomerata |
| Latticed heath Chiasmia clathrata |
Near Threatened | Lathyrus pratensis, Trifolium spp. |
| Small heath Coenonympha pamphilus |
Near Threatened | Agrostis spp., Cynosurus cristatus, Festuca spp. |
| Grey pug Eupithecia subfuscata |
Near Threatened | Centaurea spp. |
| Scarce forester Jordanita globulariae |
Near Threatened | Centaurea nigra |
| Wall Lasiommata megera |
Near Threatened | Agrostis spp., Dactylis glomerata |
| Rosy minor Litoligia literosa |
Near Threatened | Dactylis glomerata |
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.