Sunday, 8 March 2015

Cwm Cathan

Typical valley profile
Yesterday I walked an 800m section the Afon Cathan which runs along the Carms/Glam border. My aim was to do SN60P and I managed 65 species in the square, with and extra 16 species just outside. Given the amazing abundance of Hookeria and Hylocomium, I thought this ancient woodland would have produced a bit more variety than it did, however, the valley is not particularly incised, nor are there any real boulders or cliffs to speak of, plus it is very acidic. In contrast to Sam’s incredible list from Snowdonia, the most interesting species logged here included Brachytheciastrum velutinum, Dichodontium palustre (VC44), Fissidens bryoides var. caespitans, Lejeunea cavifolia, Nardia compressa, Orthotrichum stramineum, Pellia neesiana (VC44) & Saccogyna viticulosa. Some early flying Philopotamus montanus provided a nice diversion.

...about as wild and rocky as things got.
Above left Philopotamus montanus, right a few localised mounds of Pellia neesiana on the vc44 side
Hookeria lucens abundant
Nardia compressa


  1. Nice to see all that Hookeria, one of H's favourite mosses.

  2. I can't say I've seen it anywhere else in such abundance; this and Hyocomium really characterised the riparian corridor. The woodland along the river margins is possibly a mosaic of poorly defined W11b and W17c (NB I'm not that confident assigning NVC categories as they so rarely fit the descriptions that well), but if ever there was a case for a Hookeria-Hylocomium variant this is one! I dare say Sam must have considerable experience in assigning such communities?