The Cors Caron sequence of peat domes (also known as Tregaron Bog) developed on the floodplain of the Afon (River) Teifi in mid-Wales now represents the most intact surviving example in the UK of a raised bog landscape (macrotope). The three main extant domes are hydrologically isolated by the River Teifi and associated surface drainage features, and all three have suffered extensive damage as a consequence of past drainage and peat-cutting. The river terraces associated with the component bog mesotopes are regularly flooded and support vegetation that includes reed canary-grass "Phalaris arundinacea", soft rush "Juncus effusus", purple moor-grass "Molinia caerulea" and, more rarely, water sedge "Carex aquatilis". Substantial areas of the surface of each of the three component bogs still retain good quality active raised bog vegetation mainly referable to NVC type M18 "Sphagnum papillosum – Erica tetralix" community, with frequent bog-rosemary "Andromeda polifolia" and white beak-sedge "Rhynchospora alba" and, more locally, the bog-mosses "Sphagnum magellanicum" and "S. pulchrum". Extensive areas with a high cover of heather "Calluna vulgaris" and deergrass "Trichophorum cespitosum" are also present, while purple moor-grass "M. caerulea" is particularly prominent on the more modified bog margins. Although present as an important peat-former until as recently as the 18th century, "Sphagnum imbricatum" is absent from the contemporary bog flora.