Tyn y Coed forestry

A rather belated post. Last Sunday morning Karen Wilkinson and I spent a chilly few hours square bashing at Tyn y Coed forestry in monads ST0882 and ST0883 (at the boundary of Cardiff and RCT). This mixed woodland site proved to be quite humid and bryo-rich, though nothing remarkable was recorded. The best records were a small patch of Neckera pumila on hazel and a single cushion of Ptychomitrium polyphyllum (the first time I've seen it in Cardiff, and this updates Roy Perry's 1974 record for ST08). Lejeunea lamacerina and cavifolia were both recorded.

The Ptychomitrium was growing on a sandstone retaining wall in what is probably an old sidings yard. This proved to be the most interesting patch we looked at, with a mix of calcicoles (e.g. Ctenidium molluscum, Bryoerythrophyllum recurvirostrum) and acid lovers (e.g. Diplophyllum albicans) on different parts of the unmortared wall. A Polytrichastrum with branched stems got me excited and looked for all the world like the alpinum I've seen in the uplands, but proved on microscopic examination to be just formosum.

Terrible camera phone photo of sidings yard with retaining wall at rear

As usual I have a query. The small Fissidens in the photos below was growing abundantly on the vertical face of the concrete block on the left-hand side of the above photo.There was only one capsule in my sample (other setae were headless) and this looks slightly inclined (see lower photo) but that might just be due to distortion caused by being dried and rewetted a couple of times. Assuming capsules aren't inclinded, it keys out using Smith as F. limbatus based on the small leaf cells (mostly 6-8 microns wide in my sample). The perichaetial leaves do look rather long and narrow. Thoughts welcome.