Before The Water Levels Rose

Drawdown zone at Llys-y-fran Reservoir, with Riccia huebeneriana

September was so dry, that I thought I'd better find the time to explore a few dried-up ponds and lakes in Pembrokeshire. At Llys-y-fran, the only large reservoir in the county, Ephemerum crassinervium ssp. sessile was frequent amongst Ephemerum serratum in the area where Sam found it on the south-western edge. A few shoots of Pohlia bulbifera on the rocky shore south of here were new to the site (and in a different habitat to the usual local sites on sheep-walks on wet ground in the hills). The best find though was the large population of Riccia huebeneriana on silty ground in the next inlet to the north - a new liverwort for the county.

The same Ephemerum combination is on two ponds here at Wyndrush Pastures SSSI, both dug within the last 12 years, and both with shallow clay margins specifically designed to encourage bryophytes. Weissia rostellata was also starting to fruit on these ponds, and Aphanorrhegma patens is spreading. I've also picked up two more sites for Ephemerum crassinervium ssp. sessile - new to the St David's area in typical habitat on a small area of open clay ground on the Airfield Heaths, and in a less expected location on a track edge at Knapps Farm, Martletwy. If it's in such mundane habitat here, it could be much more frequent than realised, although the possibility of me inadvertently bringing it here on my visits to the apiary can't entirely be ruled out.....

Aphanorrhegma proved to be abundant in several new sites, including old limestone quarries at Pincheston (near Redberth) and a couple at Ludchurch. Pincheston Quarry also had some Riccia cavernosa, which is otherwise only on the south coast at Stackpole and Broomhill Burrows. One of the Ludchurch sites - Croft Quarry - has three fine old lime kilns hidden in woodland at the lake edge, and Platydictya jungemannioides was a nice find amongst Anomodon viticulosus and other mosses at the base of one of these. Leptobryum pyriforme was also on a worked quarry face near here.

Lime kilns at Croft Quarry

Riccia cavernosa at Pincheston Quarry

I went looking for Ephemerum crassinervium ssp. rutheanum (E. hibernicum) in the dried-up quarry at Bosherston, which functions something like a turlough, and also at Bottom Meadow Quarry in West Williamston. No joy, but the latter has a far more extensive population of Ephemerum recurvifolium than I'd realised, with numerous patches in quite a few places -- both in the drawdown zone and on drier ground above the pools. I've recently found it to be much more widespread at Castlemartin Range as well, so that's two strong populations of an otherwise rare species in Wales. A botanical bonus at Bottom Meadow came in the form of a hybrid horsetail, Equisetum x robertsii, which was subsequently confirmed by the referee and is I think the only record away from Anglesey.

One of the many Ephemerum recurvifolium sites at West Williamston