Dumfriesshire Botany Group at Powhillon Farm – 14th August 2022
On one of the last of the very hot days in August we visited Powhillon Farm courtesy of Dave Pickett, Manager for the WWT Caerlaverock Reserve. We were met by Dave with Lucy and Sue. All joined us for the morning and Dave stayed with us all day taking us to different parts of the site.
Powhillon Farm is owned by WWT though separated from the main visitor facilities by the Lochar water. The land is saltmarsh and wet fields that are grazed by cattle and sheep to keep the sward suitable for the large flocks of geese, particularly the barnacle population from Svalbard, that arrive in the Autumn and stay on the Solway through to Spring.
From the farm we initially stayed in the most landward square which extends across the Bankend road to the lower parts of the Lochar Moss. Indeed all of this land was probably once peatland that has been cut away and drained to make the wet pastures that are present today. All of the land lies below 10m so a good part of it is subject to tidal inundation meaning that brackish conditions are present throughout.
Some of these higher level fields are quite improved and species poor but at a slightly lower level there was a normally much wetter field which had not been grazed and here the flora was more diverse. Large stands of Sea Club-rush, Bolboschoenus maritimus and patches of Common Reed Phragmites australis gave structure. Where water stands longest there were patches of both Common Spike-rush Eleocharis palustris and Slender Spike-rush Eleocharis uniflora. We were able to see that the lower glume completely encircles the spikelet in Slender Spike-rush, which is a strictly coastal species, but not in Common Spike-rush. We found a stand of Grey Club-rush Schoenoplectus tabernaemontani which is always nice to find and saw it elsewhere later.
We continued south into the next square and this took us eventually to the edge of the Lochar as it opens into the Solway and onto the higher level saltmarsh which lies within the Solway SSSI. We picked up some typical upper saltmarsh species including Parsley Water-dropwort, Oenanthe lachenalia; False Fox Sedge, Carex otrubae; Celery-leaved Buttercup, Ranunculus sceleratus, Sea Rush Juncus maritimus; Distant Sedge Carex distans ; Sea-spurrey Spergularia marina and Greater Sea-spurrey Spergularia media.
Lunch was taken under shade back at the farm. After lunch we went west and picked up the bank of the Lochar Water again and followed the sea wall down to a big bend. This area was a bit more diverse having both saltmarsh, brackish and fresh water marsh species. Along the sea wall it was nice to find Spiny Restharrow Ononis spinosa still in flower. An onion on the edge of the lochar with mixed flower and bulbils proved to be Sand leek, Allium scorodoprasum. Between the sea wall and the Lochar some normally wet scrapes and depressions had dried out but contained an interesting set of species including the best finds of the day. There was Marsh Yellow-cress Rorippa palustris, Lesser Centaury Centaurium pulchella, Brackish water-crowfoot Ranunculus baudotii, Frog rush Juncus ranarius and Mudwort Limosella aquatilis. Three of these are exciting finds. Lesser Centaury has only three previous records in Dumfriesshire. Two of these, one from the eighteenth century and one in 1970, were in the Caerlaverock area. Frog Rush has one previous record in the County in the Caerlaverock area by Olga Stewart in 1979. The specimen we found was confirmed by the referee Mike Wilcox. It is close to the much commoner Toad Rush Juncus bufonius but has more clustered flowers and blunt capsules and is a coastal specialist.
Mudwort has never been recorded in Dumfriesshire so this is a first record. There is a scatter of records across the Nith in Kirkcudbrightshire but this inconspicuous annual species is now a rather uncommon and declining species of muddy edges of running or standing water. It is not confined to coastal habitats and worth looking for.
Chris Miles
BSBI county recorder for Dumfriesshire VC73 – see bsbi.org/dumfriesshire
