Bygone bryologists hang your heads in shame

This is Rhaeadr Ddu - the most spectacular waterfall on the Afon Gamlan in Coed Ganllwyd NNR, Meirionydd.  A recent survey by Des Callaghan has helped to confirm this woodland as the richest for oceanic bryophytes in Wales and the site with the largest Welsh populations of a large number of species such as Cephalozia catenulata and Sematophyllum demissum.  Des did not refind the Nationally Scarce, Section 42 Paraleptodontium recurvifolium there, and nor has anyone since 1958.  I spent half an hour today searching specifically for it and found none, though it is just possible that an abseil survey might reveal it.  Its loss is a sad tale of thankfully bygone days:

Last month I looked at all of the Welsh specimens of Paraleptodontium in the NMW herbarium, just to confirm that the species really was historically present at 10 or so Welsh sites.  All were correctly identified and all were depressingly, grotesquely large.  Between 1900 and 1958 the colony at Coed Ganllwyd was plundered for private collections and for 'distribution' to other bryologists and herbaria repeatedly, and there are more than 25 specimens from the site.  Many of these are 10x20cm pure patches, suggesting that bygone bryologists grabbed good handfuls of this rare species.  The last collection is from 1958, and its collection (by a now deceased bryologist who I will not name here) horrified Derek Ratcliffe who witnessed the event.  The collector actually said it was the last bit that he could find on the site!

Most of the specimens of Paraleptodontium from Rhaedr Ddu contain bits of Breutelia chrysocoma and/or Sphagnum denticulatum, and the 1958 specimen says "growing through Campylopus setifolius opposite the main waterfall".  As I had seen C. setifolius there on previous visits I knew just where to look, so I had a glimmer of hope that Paraleptodontium could have survived; it hasn't.  The associates are all still there and look spectacular, especially the large patches of the Campylopus.

Despite this loss, Coed Ganllwyd is the most wonderful place in which to see oceanic bryophytes - take a hand lens and the Field Guide (and even better a bryologist who can show you what's there) and admire boulders and rockfaces covered with Sematophyllum, Drepanolejeunea, Harpalejeunea, Colura, Adelanthus, 6 species of Plagiochila, Hypnum callichroum, Dicranodontium denudatum etc. etc.  It is just a 5 minute walk from the National Trust carpark at Dolmelynllyn, Ganllwyd.  Just please don't collect any specimens!

Thatch moss and a first for Glamorgan...

Today was a bitty sort of day, spent just west of Cardiff.  Most important was attending Roy Perry's funeral, as Roy launched me into bryology by lending me 'Watson' in 1996, and then steered me back on to the right path in 1999 when birding was proving too much of a distraction!  I'd probably be a full-time birder or moth'er if it hadn't been for Roy.

My main work of the day was helping Richard Lansdown with his survey of Thatch-moss (Leptodontium gemmascens) at Cosmeston Medieval Village.  Richard found this UKBAP moss new for Wales a couple of weeks ago, on two areas of low-hanging thatch, but today's ladder survey revealed patches on 5 of the site's 10 buildings and suggests there's a thriving Welsh population of this species.  I forgot my camera, but will post a couple of Richard's pics sooner or later.  If anyone wants to see Thatch Moss, look on the southern roof of the southernmost of the three linked buildings (the Reeve's Cottage, http://www.valeofglamorgan.gov.uk/Documents/Enjoying/Visit%20the%20Vale/Places%20To%20Go/Parks%20and%20Gardens/cosmeston/Medieval%20village%20Map.pdf): it's at head height above the door as well as on the SE corner, where shaded and kept damp by the roadside hedge.

 

I arrived slightly early at Cosmeston, so spent 20 minutes on the suburban clifftops north from Lavernock point (ST16Z).  Shaded tarmac was rather productive here, with Dialytrichia mucronata, Syntrichia latifolia and Didymodon nicholsonii, alongside a puzzling blunt-leaved, non-fruiting Orthotrichum that will remain unidentified.  A wander southwards revealed an arable field with its margins recently ploughed, where 3+ patches of Ephemerum recurvifolium made a nice addition to the Glamorgan list.  The sticky calcareous clay of this field also looked perfect for Microbryum floerkeanum, but I had little time to search and the ploughing had decimated the potential habitat.  George - finding this tiny Microbryum new to Glamorgan is your challenge for 2015...

After my visit to Cosmeston I spent 30 rain-soaked minutes bashing ST16P, getting ca. 40 species, including Syntrichia latifolia, S. laevipila, S. papillosa, S. montana and S. ruralis, more Dialytrichia, and not a lot else!