Cefn Blaenau

Cefn Blaenau is a 23-hectare Site of Special Scientific Interest in a small upland valley in Carmarthen and Dinefwr, Wales. It was designated an SSSI in 1989, primarily for its flush and spring vegetation as well as the diverse mosaic of unimproved pasture, ‘ffridd’ land (steeply sloping land between enclosed fields and open hills, often dominated by bracken or gorse), marshy grassland, wet heath, acid grassland, broadleaved woodland, streams, and small rock outcrops. These habitats, which are well represented at this site, have been greatly reduced in north Carmarthenshire due to land improvement, agricultural intensification, and afforestation. Only about 140 hectares of flush and spring vegetation remain in the county. The headwaters of the River Marlais (a tributary of the Cothi) run through the valley bottom in a series of mires, merging into areas of wet healthy pasture dominated by purple moor-grass (Molinia caerulea) and rich in sedges. In the very wet, flushed mire areas there are many bog-mosses Danthonia decumbens (Sphagnum spp.) and other localized plants such as: marsh St John's-wort (Hypericum elodes), round-leaved sundew (Drosera rotundifolia), common butterwort (Pinguicula vulgaris), and bog pondweed (Potamogeton polygonifolius). At the base of the valley slopes, boggy areas contain common cottongrass (Eriophorum angustifolium), cross-leaved heath (Erica tetralix), common bilberry (Vaccinium myrtillus), marsh lousewort (Pedicularis palustris), and many-stalked spike-rush (Eleocharis multicaulis). The wet pasture supports uncommon species such as whorled caraway (Carum verticillatum), bog asphodel (Narthecium ossifragum), and heath spotted-orchid (Dactylorhiza maculata subsp. ericetorum). Along streamsides, linear areas of poor-fen vegetation occur, including various rushes (Juncus spp.), ragged-robin (Lychnis flos-cuculi), marsh thistle (Cirsium palustre), greater bird's-foot-trefoil (Lotus uliginosus), marsh bedstraw (Galium palustre), sneezewort…