Finally an update on this Syntrichia
from Llanishen in February. I have now prepared a nerve section as
recommended by Nagy in the comments. This appears to confirm S. virescens
new for Glamorgan. Not the best prep or photo - but compared to my
usual nerve sectioning abilities I'm pretty chuffed! I'll send a voucher
to Tom Blockeel.
A small Syntrichia growing on the trunk of a street lime caught my eye as I was walking to the woodland south of Llanishen Reservoir for a quick square bash. It looks reasonably convincing for S. virescens, with toothed hairpoints and notched leaf apices, though the length of the basal cells (30-62 microns, averaging 37-45 microns) straddles the ranges given in Smith for differentiating S. virescens and S. montana. It was certainly smaller than typical montana, but as virescens would be new for VC41 I'm being cautious and seeking the opinion of others - thoughts welcome.