Cae Cwm-rhocas (Cwm Roches Meadow)

Also within

Powys County

Habitats

Carr, Fast flowing river and stream

Description

Description This site comprises a single large hay meadow situated on gently sloping ground in the valley of the River Ithon at Penybont. It supports an unusual plant community that has strong affinities with those found in certain flood-meadows in central and southern England. The sward is characterised by an abundance of common bent Agrostis capillaris, sweet vernal-grass Anthoxanthum odoratum, red fescue Festuca rubra, Yorkshire-fog Holcus lanatus and clovers Trifolium spp., with frequent meadowsweet Filipendula ulmaria, ribwort plantain Plantago lanceolata, meadow buttercup Ranunculus acris, yellow-rattle Rhinanthus minor, common sorrel Rumex acetosa and great burnet Sanguisorba officinalis. There is a wide range of associated plants, including meadow foxtail Alopecurus pratensis, soft-brome Bromus hordeaceus subsp. Hordeaceus, yellow oat grass Trisetum flavescens, common knapweed Centaurea nigra, common mouse-ear Cerastium fontanum, meadow vetchling Lathyrus pratensis, autumn hawkbit Scorzoneroides autumnalis, rough hawkbit Leontodon hispidus, oxeye daisy Leucanthemum vulgare, common bird's-foot-trefoil Lotus corniculatus, adder's-tongue Ophioglossum vulgatum, creeping buttercup Ranunculus repens, common dandelion Taraxicum officianalis and tufted vetch Vicia cracca. Species indicative of meadows in more upland situations are also present. These include smooth lady's-mantle Alchemilla glabra, intermediate lady's-mantle Alchemilla xanthochlora, pignut Conopodium majus and bitter-vetch Lathyrus montanus. On its western side the meadow grades into alder Alnus glutinosa carr at the edges of a small lake. A stand of planted broadleaves here supports a small heronry (heron). Further interest is added by the presence of ancient oak trees Quercus spp. within the meadow.

Species mentioned

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.

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