Before the floods

I had a few spare hours last Friday but without aceess to a car, so I took a train ride to Treforest Estate to boost the coverage in tetrad ST18D. Little did I suspect at the time that this area would be among the worst hit by Storm Dennis less than 48 hours later.

The most interesting habitat proved to be the damp, NE-facing retaining wall which separates the railway line from a lane alongside it. Among the 17 species present here were several patches of Preissia quadrata spreading along mortar lines and adjoining stonework. Peter Sturgess has recorded this species from the same habitat in an adjacent tetrad.

The Taff riverbank felt like familiar hunting ground from my time spent exploring this habitat in Cardiff, with characteristic species including Homalia trichomanoides, Cinclidotus fontinaloides and Dialytrichia mucronata. There was also a small patch of Anomodon viticulosus, only the second time I've seen it by the Taff, and some Fissidens crassipes on riverbank rocks. Two days later these rocks would've been under several metres of water, and some of these bryophytes might now have been scoured off.

Epiphytes near the river included what appears to be Pylaisia polyantha on a fallen sycamore branch. There were no mature capsules with lids to make the identification straightforward, but the combination of multiple generations of capsules, evenly thickened exothecial cells walls in the capsules (photo below, bottom right) and some flat-ended basal cells in the leaves are hopefully sufficient to rule out Hypnum resupinatum.

The visit increased the total for this tetrad by about 50, from 28 to 78 taxa. I just had time to call into ST08Y before catching the train home. This tetrad already had a decent total of 47 taxa but was lacking in epiphytes, so it was quick work to boost it to 63 taxa after checking a few Ash trunks.