Tâf Fechan [SO01K square bash]

Left vc42, right vc41

As I was in Merthyr on Friday and I had a spare hour, I made a quick sojourn into SO01K, which was on a paltry 10 species. Even within my limited time slot I was able to quickly add an additional 64 species to the list for what is undoubtedly a much richer partial tetrad. There was also interest before reaching my target the square, when crossing Pontsarn viaduct I noticed a nice colony of Grimmia orbicularis on the Brecon side, new for vc42 according to the blog county lists.

Once in the square a large decorticated log was found to hold a good colony of Riccardia palmata (below; photo 1) and the limestone outcrops & boulders supported abundant drapes of Neckera crispa on dry cliffs with sheets of Conocephalum salebrosum in damper sections. The most interesting species of the drier sections were Loeskeobryum brevirostre (photo 2), Scapania aspera (photo 3) and Platydictya jungermannioides (photos 4-7), the latter new for Glamorgan with 3 small colonies noted in crevices, but with plenty of the same habitat, it seems likely there will be a strong population at this site.

 

Interest on the wetter sections was provided by Cololejeunea calcarea, Eucladium verticillatum, Leiocolea bantriensis (below; photo 1) and Seligeria acutifolia (photos 2 & 3). Well worth a revist - park on the vc42 side of the bridge, cross over and drop down from the Glamorgan side - very easy access.

 

 

Sychryd scramble

On the 20th a climb up through the complex of boulders and falls along the Glamorgan side of the Sychryd boosted the totals for SN90D from 90 to 159 and SN90E from 41 to 106. Highlights from the limestone section included scattered colonies of Cololejeunea calcarea (photo 1 below), Neckera crispa (just one small tuft noted), Oxyrrhynchium schleicheri (one small colony), Rhynchostegiella teneriffae (sheets of it above water line, photo 2), Seligeria acutifolia (small amounts at 2 locations, photo 3), S. donniana (only 1 fruiting patch seen,, photo 4), Taxiphyllum wissgrillii (1 patch noted on a small embedded rock) & a little Dermatocarpon miniatum (photo 5).

A couple of logs in the higher acid section of the gorge supported species including Barbilophozia attenuata, Blepharostoma trichophyllum, Cephalozia catenulata (photo 1 below), Dicranodontium denudatum & Riccardia palmata, plus there were a couple of nice patches of Hymenophyllum tunbridgense half way up the valley side.

Of note for the wrong reason was a single 10cm x 10cm patch of Lophocolea semiteres established on the track as you walk down the north side of Dinas Rock.

Earlier in the day on the way up the Neath Valley, three lay-by stops along the A465 all showed that the putative Didymodon australasiae is a well established component of the verge dirt zone along this road. A little Ephemerum minutissimum was also collected and checked under microscope at one of the stops.

A visit to Darren Fach SSSI

A week ago I visited Darren Fach and Darren Fawr - on the Carboniferous Limestone north of Merthyr Tydfil - with 4 NRW colleagues to remember the massive role that David Stevens played in Welsh nature conservation.  We paid our respects to Sorbus leyana and Dryopteris submontana, following in David's footsteps, and I made a search for one of David's favourite Welsh bryophytes, Tortella densa.  His initial discovery of this species, new for Wales, was on the limestone of Great Orme's Head, and the only other Welsh record comes from the Clwyd limestone near Llangollen, but I hoped that Darren Fawr might offer a good chance.  The Tortella hunt was disappointing, as were the bryophytes of the general area, which is very dry and exposed.  Final tally for the area (split between SO0110, SO0210 & SO0209) was less than 50 species, with a few additions to tetrads I hope.  Highlights were Seligeria acutifolia and Grimmia hartmannii in the woodland below Darren Fach.  My previous visit to the southern end of Darren Fawr in SO0209 was similarly bryo-poor.

Nedd-fechan in pictures 1

Part of a length cliff with lots of, mostly non-fruiting, Seligera (photo 2), though Sam did manage to find a few with capsules [of acutifolia (photo 3) and donniana (photo 4)]. Also there were good patches of Cololejeunea calcarea (photo 5) all along the same face.

Lower down the valley, where the woodland flora reflected more neutral-acidic conditions, there were areas in which Loeskeobryum brevirostre pretty much blanketed every surface on the woodland floor, along with with frequent Rhytidiadelphus triquetrus and a little R. subpinnatus.

Grimmia hartmanii was noted on millstone grit boulders and would appear to be thinly but widely distributed through this section of ravine.