My most surprising bryo find of the winter so far has been
Ptychomitrium polyphyllum growing just a stone's throw from the Butterfly Conservation Wales office in Hafod, Swansea. I first noticed a cushion of this moss growing on the sandstone coping of a sloping wall back in November, but only remembered today to take my camera along to get a few photos. I must have walked past it countless times last year before I noticed it. The moss is in the foreground of the photos below. It is close to a busy road junction and must experience pretty high levels of nitrogen pollution.
I noticed today that as well as the large fruiting cushion there is a small non-fruiting cushion nearby (on the right-hand side in the photo below left).
The associates are all mundane species: mostly
Grimmia pulvinata with some
Bryum capillare and a tiny amount of
Tortula muralis. The rest of the wall is almost devoid of moss apart from a few scraps of
G. pulvinata here and there.
I've not seen this moss in an urban situation before, but perhaps it isn't so unusual. Sam's Pembrokeshire flora mentions its persistence on imported rocks at County Hall in Haverfordwest, shwoing it can survive some pollution.
