Thursday, 5 March 2015
Ulota calvescens - now fruiting on a tree near you
This photo was taken last April at Carmel, but the season for spotting this increasingly frequent moss has now begun. I found a few tufts with young capsules and classically sparse-haired calyptrae today near Pembrey. The very long seta is also characteristic.
Beware that some Ulota calvescens can be hairier than this, resembling U bruchii, so you sometimes need to check the mature leaves from lower parts of a stem (ie the darker green/brownish leaves not fresh young ones) for a 'vitta' of long, narrow, hyaline cells running up from the leaf base about midway across from nerve to margin. It's possible that some U bruchii and U crispa might be this sparsely haired, but that would be a rare occurrence.
Ulota calvescens had two Welsh and only one or two English records at the time of the first Atlas, and when I published the Pembs Flora in 2010 my Pembs record was mirrored by two in SW England and the two historic N Wales ones. Graham and I have now found several colonies in Brecs, Carms and Ceredigion, and today's record is the 10th for Carms. There are also lots of records from the Pennines, we had it in Dorset last summer, and even in East Sussex on the last BBS Spring meeting. This would have been unthinkable 10 years ago!
People might have overlooked hairy forms, and these seem to be relatively frequent in the Pennines, but I doubt very much that these classic sparsely hairy forms would have been missed. I am absolutely sure that this is another spreading Colura-type bryophyte that is benefitting from coniferisation, reduced pollution and climate change.