Severn Estuary Shore IPA

Location: Bristol Channel shores near the Severn river mouth.

Grid Reference: ST 620 980

Severn Estuary Shore IPA has been recognised as one of 165 Important Plant Areas in the UK.

The key features of this IPA are:
• The species richness of vascular plants in littoral sediment

The IPA is made up of a succession of habitats ranging through intertidal mudflats, saltmarsh, shingle beach and grazing marsh intersected by a complex network of freshwater and brackish ditches. It also includes Berrow Dunes, a complex of salt marsh, dunes, stable dune grassland, dune slacks, scrub and a freshwater lagoon. The site is important for its rich flora associated with coastal sediments – the saltmarsh and grazing marsh found all along the estuary's fringes.

Only a limited number of salt tolerant plants can grow in the conditions found in the estuary, and those to be found here include nationally rare and scarce species such as bulbous foxtail, long-stalked orache, slender hare's ear, sea barley and sea clover. In summer there are bright displays of sea lavender and sea aster, and you might find sea purslane, sea wormwood, sea plantain, marsh mallow, seablites or glassworts. Some areas are dominated by common reed, while more palatable grasses with sea couch grass are found on the grazed areas.

The sand dunes of Berrow add to the site's interest, with a rich and diverse flora. Here Somerset rush may be found in its only British locality, and one of only two native colonies of round-headed club-rush, as well as a range of nationally declining species such as divided sedge, marsh helleborine and the handsome lizard orchid. In the foredunes, nearest the sea, little plant life is to be found except marram grass and lyme grass, and slightly further back, sand sedge, sand couch and sea spurge. Further back still, though, in the fixed dunes, the marram grass and lyme grass are replaced by new plant communities dominated by red fescue grass and the spikes of the small, yellow flowers of lady's bedstraw, together with a wide range of flowering plants including restharrow, bird's foot trefoil, salad burnet, yellow rattle, hare's-foot clover, pyramidal orchid and bee orchid.

Behind, in the dune slacks, you might find wetland flora such as marsh pennywort, wild celery, parsley water-dropwort, common fleabane, marsh helleborine, early marsh-orchid or southern marsh-orchid. It is in one small dune slack here that the round-headed club-rush occurs. A large lagoon known as Berrow Marsh runs along the south-western edge of the dunes. Common reed predominates, but it is here that the Somerset rush may be found, together with branched bur-reed, bulrush, common meadow-rue, marsh arrowgrass, sea club-rush and yellow iris.