Friday, 10 February 2017

Cwar Du - a boost to SN90F

I spent my lunch hour (well actually a split 20 minutes before and after my main work) recording in SN90F, east of the A4061 between Treherbert and Craig y Llyn.  This was slightly pointless because there were already over 70 species recorded from the tetrad, but it looked like good ground as I drove past and I thought I'd add something.  In the end I found about 95 species, and there were 14 on the previous list that I didn't see (mostly plantation & track species), so the tetrad is now nicely over the 100 mark and can probably be regarded as 'done'.

First stop was a small, sealed-up, graffiti-covered building surrounded by sculptures, where I recorded various ruderals including Tortella tortuosa, Orthotrichum cupulatum and Schistidium apocarpum on concrete.  A yomp up through scree with 4 cushions of Scapania gracilis led to the Cwar Du cliff base at 450m altitude, where Ditrichum zonatum new for Glamorgan awaited me.  Nearby were Campylopus atrovirens, a small form of Gymnocolea inflata, some Lophozia sudetica, and a bit of Rhabdoweisia crispata.  A rowan added Cololejeunea minutissima and other common epiphytes to the list.

After I'd finished my work near Glyncorrwg I stopped briefly at Nant y Bwlch, just down from Cwar Du, to add some stream mosses to the list.  Hygrohypnum ochraceum and Hyocomium armoricum were present in the stream, Ptychomitrium polyphyllum was on boulders, Polytrichum alpinum was on a low cliff, and slight base enrichment was indicated by a few shoots of Trichostomum brachydontium among Amphidium mougeotii.  Perhaps the highlight of this area was some Lophozia bicrenata with perianths on humus under heather - a thoroughly unpredictable species.

So, a worthwhile stop given that I didn't have time to properly bash an unknown tetrad.


  1. 95 species in 40 minutes, and a new county record to boot - I don't know how you do it!

  2. That's the third new addition to the Glamorgan list already this year, exactly half of last years total. I've updated the vc41 list which now stands at 561 taxa.

  3. Great record which builds on the impressive collection of montane/alpine species in that area. I imagine that searching other, similar gullies and crags in RCT and the Upper Ogwr vale will be rewarding, although some are rather inaccessible. In the light of this discovery it's probably worth looking for it at Craig y Llyn and Cwm Dare.

  4. Looking at Barry's county lists tab, I make that 39 additions to the Glam flora since the renaissance in bryo recording circa 2010. This averages just over 5 new species per year for the period 2010-2016, so with 3 already this year we're off to a good start.

    I'd imagine most if not all of these species are at Cwm Dare - I fear I'm overlooking the Lophozias in particular.

  5. I have a nagging feeling I saw Ditrichum zonatum at Craig y Llyn, or something resembling it but unconvincing. Cwm Dare needs several visits as it's a vast area of good habitat, and there's very little previous coverage. Hints of base-enrichment at Nant yr Bwlch (and Craig y Llyn) make me think that whoever hits the rich ground on these crags could find something really special. It's also worth bearing in mind that Andreaea alpina grows alongside Ditrichum zonatum in several places in the Beacons.

  6. NB I can't take credit for the county list tab, that is Sam's work. I've just kept it updated.