On Sunday I helped out at a habitat management work party at Blackrock Quarry, just north of the A465 near the Clydach Gorge. I only had time for a quick poke about at the base of the limestone quarry face near where I was working, but I was pleased to see plenty of Gymnostomum viridulum growing on soil in crevices - a new species for me. Under the microscope it was good to see numerous multicellular gemmae in the leaf axils.
In the same habitat, and probably of greater interest, was what I think is one of the bryoparasitic ascomycetes which Sam brought to our attention recently. A single orange apothecium caught my eye among a patch of Trichostomum crispulum (I managed to break it in two during collection - see photo below). Microscopic inspection revealed the spore structure nicely (photos below) but I have failed to key it out satisfactorily using the German website. The apothecium was large by the standards of this group, with a diameter of 5mm. No species are listed on the website as parasitic on Trichostomum, though some use the related Tortella and Weissia.