Also on these rocks are numerous cushions of Cynodontium bruntonii. The mamillose cells are readily apparent in section but the way the leaves get markedly longer going up the shoot is proving to be a useful indicator in the field, at least for separating it from Dicranoweisia cirrata. No rare Grimmias as far as I can see but will keep looking.
The valley opens out into moorland at the top with some very old sunken trackways. The banks of these have fine colonies of bryophytes, in some places with good patches of Anastrepta orcadensis easily picked out from surrounding Barbilophozia floerkii by the dark brown gemmae.
On the vertical peat edges of one of the tracks, where cut by vehicle tyres, are tiny patches of Cladopodiella francisci, difficult to find buried under filamentous algae and surely much overlooked in this most unglamorous of habitats. Another under-recorded moss on these tracks is Polytrichum commune var. perigoniale.
I’ve spent many hours identifying Racomitrium spp. To start with I couldn’t find anything other than R. affine but after cutting innumerable leaf sections, R. heterostichum was finally found but only on the rocks along the ridge at the top of the valley with all material from the valley sides proving to be R. affine. Also on rocks at the top are many small cushions of R. sudeticum, hardly resembling the other members of this group. I'll try and put some notes together on some of these segregates, including R. obtusum I hope, but I'm still learning at the moment!
I’ve followed in Sam’s footsteps to a few other sites nearby, particularly where basic rock intrudes through the very acid shales that dominate the geology here. Bryn Bras proved an excellent spot and I refound most of Sam’s goodies but Sphagnum skyense eluded me. I was able to add Cephalozia pleniceps from a small bog on the moorland above the cliffs and there was Barbilophozia atlantica on a boulder by the river. The Bwlchglas mine still has Ditrichum plumbicola but clearly much reduced from 2005 when Sam described it as being abundant in the identical spot. A walk to Craig y Pistyll via Banc y Garn got no further than Banc y Garn as the basic outcrops and flushes there were just too tempting with sheets of Preissia quadrata pointing the way. Not much new for the site although a large colony of Rhabdoweisia crenulata was a nice way to end the day.
More news soon. Tom.