Roundton Hill

Site of Special Scientific Interest · 52.5479, -3.0428

Also within

Powys County

Habitats

Bracken scrub

Geology & landscape

Geological Feature: Rock Outcrop

Landscape processes: Volcanic / Igneous

Description

Description This site is of outstanding interest for its grass-heath habitat with the presence of spring ephemerals in xerophytic grassland (adapted to dry conditions) and for its diversity of lichen species. Two nationally rare species of moss also occur here. Lying at 200-370 metres Roundton Hill is round in plan with steeply sloping east, south and west slopes. It has much rock exposure, is well drained and is subject to summer drought on its southern aspects. Much of the vegetation is acidic/neutral grassland dominated by bents and fescues Agrostis/Festuca with much western gorse Ulex gallii and areas of bracken Pteridium aquilinum. Although typical grassland species include heath bedstraw Galium saxatile, sheep’s sorrel Rumex acetosella and bird's-foot-trefoil Lotus corniculatus, more base-rich areas also include wild thyme Thymus praecox and lady’s bedstraw Galium verum. This vegetation type, which is not common, occurs particularly in western Britain, and in the Welsh Borders seems to be confined to areas of volcanic-derived soils. Notable plant species occurring in this dry vegetation type include rock stonecrop Sedum forsterianum, knotted clover Trifolium striatum, carline thistle Carlina vulgaris and the spring annuals shepherd’s cress Teesdalia nudicaulis and upright chickweed Moenchia erecta. The dry southern aspects support over a hundred species of lichen ranging from numerous Cladonia species in the turf to rich rock encrustations of the type Lecanoretum sordidae, with a strong representation of the genera Parmelia, Pertusaria, Rhizocarpon, Lecidea, Lecanora and Diploschistes. The nationally rare moss species which occur are Tortula canescens and Grimmia laevigata. Bryophyte-rich areas tend to be confined to local flushes.

Species mentioned

English name
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Latin name
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IUCN / Red List Type Family
bracken Pteridium aquilinum LC fern dennstaedtiaceae
carline thistle Carlina vulgaris LC herb asteraceae
heath bedstraw Galium saxatile LC herb rubiaceae
lady's bedstraw Galium verum LC herb rubiaceae
birdsfoot trefoil Lotus corniculatus LC herb fabaceae
upright chickweed Moenchia erecta VU herb carophyllaceae
sheep's sorrel Rumex acetosella NT herb polygonaceae
shepherd's cress Teesdalia nudicaulis NT herb brassicaceae
creeping thyme Thymus praecox Not listed in GB list herb lamiaceae
knotted clover Trifolium striatum LC herb fabaceae
map lichens Rhizocarpon Not listed in GB list lichen rhizocarpaceae
dog screw moss Tortula canescens EN moss pottiales
western gorse Ulex gallii LC shrub leguminosae

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.

SpeciesStatusVia host-plant
Black-veined moth
Siona lineata
Critically Endangered Lotus corniculatus
New forest
Zygaena viciae
Critically Endangered Lotus corniculatus
Straw belle
Aspitates gilvaria
Endangered Lotus corniculatus
Wood white
Leptidea sinapis
Endangered Lotus corniculatus
Fiery clearwing
Pyropteron chrysidiformis
Endangered Rumex acetosella
Slender scotch
Zygaena loti
Endangered Lotus corniculatus
Mouse moth
Amphipyra tragopoginis
Vulnerable Lotus corniculatus
Broom moth
Ceramica pisi
Vulnerable Pteridium aquilinum, Rumex spp.
Dingy skipper
Erynnis tages
Vulnerable Lotus corniculatus
Satyr pug
Eupithecia satyrata
Vulnerable Galium spp.
Garden dart
Euxoa nigricans
Vulnerable Rumex spp., Trifolium spp.
White-line dart
Euxoa tritici
Vulnerable Galium verum
Bedstraw hawk-moth
Hyles gallii
Vulnerable Galium spp.
Silver studded blue
Plebejus argus
Vulnerable Lotus corniculatus, Ulex spp.
Beaded chestnut
Agrochola lychnidis
Near Threatened Rumex spp., Trifolium spp.
Grey chi
Antitype chi
Near Threatened Rumex spp.
Garden tiger
Arctia caja
Near Threatened Pteridium aquilinum, Rumex spp.
Latticed heath
Chiasmia clathrata
Near Threatened Trifolium spp.
The sallow
Cirrhia icteritia
Near Threatened Rumex spp.
The Silurian
Eriopygodes imbecilla
Near Threatened Galium saxatile
Autumnal rustic
Eugnorisma glareosa
Near Threatened Galium spp., Rumex spp.
Dark-barred twin-spot carpet
Xanthorhoe ferrugata
Near Threatened Galium spp., Rumex spp.

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

W25 — Bracken scrub

Pteridium aquilinum-Rubus fruticosus underscrub

Matches 2 species from the description above: Galium saxatile, Pteridium aquilinum

Hedera 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