Porella pinnata

After completing some domestic chores in Brecon last Saturday Mrs M and I went for a quick walk along the Ghurka Way upstream of the town – we came across a large boulder covered mainly with Anomodon, but just above the water line (on the downstream side just like it says in the Field Guide) was a dark green patch, which I guessed could be Porella pinnata (I didn’t have a lens with me, but even through my rubbish eyes it looked interesting and different to Chiloscyphus) – I eventually got around to putting a stem under the microscope this morning so I could take a pic of the rounded under-leaves and small non-decurrent lobules.

Away from the west, most other records in southern half of Wales are from the River Wye (aka the River Wue according to one LRC record). This appears to be the first record of Porella pinnata from the River Usk – it may well be genuinely scarce along the Usk itself as there have been several lower plant surveys by experienced bryologists along suitable parts of the river. Perhaps some Usk tributaries, such as the Ysgir, which seem much less explored, have undiscovered populations of this liverwort.