Saturday, 19 August 2017

Frostwort in the Beacons

I recently accompanied Karen Wilkinson on a trip to Craig Waun Taf and Craig Fan Ddu - the line of crags to the south of Pen y Fan.   These are some of the most acidic Old Red Sandstone crags in the Brecon Beacons and previous surveys have shown them to support a fairly unremarkable bryophyte flora.   However, there are a few interesting species present and I have a very clear memory from 1999 of a young Sam showing me a puzzling liverwort which looked a bit like a pointed-leaved Diplophyllum / Scapania that he had collected at Craig Fan Ddu and which turned out to be Douinia ovata - the first ever record from the National Park and the first modern  record for south Wales since HH Knights found it in northern Carms and northern Brecks in the early 20th C.   After much searching, we found the Douinia to still be present and it appears to be doing well, although it is restricted to a very small area on the crags.

  
We only recorded a few additional bryophytes for the site, but one of them was rather exciting.   I have never seen a Gymnomitium south of Ceredigion, but there on one rock face were three small tufts and a few scattered patches of what looked to be G. obtusum, which if Sam agrees, it will be new to our south Wales counties.   The pics below show the tightly appressed overlapping leaves of this tiny liverwort, which has a silvery appearance when dry.  Most leaf tips of this specimen appear to be blunt, which seem to point to it being obtusum rather than concinnatum.






Much of the focus of our visit was on the vascular plants.  I knew that Silene maritima was present at Craig Fan Ddu, but I hadn't realised just how frequent it is and this species really makes it stand out from other crags in the Brecon Beacons.   A few other crag specialists including Thalictrum minus and Sedum rosea are present, but they are scarce here compared to other crags in the central and western Beacons.   Towards the end of our visit we turned a corner and were amazed to see several plants of Salix herbacea, a species I have always wanted to see in the National Park.  Overall we counted about 20 plants, about half of them tucked away amongst heathy vegetation growing along the top edge of the crags and easily overlooked.    
 The following day we checked previous Salix herbacea records for the Pen-y-Fan/ central Breacons area - to cut a long story short, the local record centre/ NBN data gives the impression that there are quite a few records for the area, however most of this is noise resulting from species compilations and centroid grid references and the only real records seem to be a 1972 record from Craig Fan Ddu and possibly the same location as ours, an unlocalised 1888 record by Ley and a 1952 record from Craig Cwm Sere, which the local BSBI Recorder is following up.   Leafminers had been at work on some Salix plants and a couple were also infected by what I hope is the fungus Melampsora arctica.    

 

 

Thursday, 17 August 2017

Plagiothecium curvifolium in Swansea

I encountered some fruiting Plagiothecium curvifolium on a chunk of bark on the floor of young oak woodland in the north of Swansea yesterday. Not one I see too often, but the almost Hypnum-like appearance of the shoots was quite striking.

Wednesday, 16 August 2017

Spongy liverworts

I can't find my Smith's Liverworts of Britain and Ireland and haven't looked at it since Jean Paton published her Liverwort Flora in 1999 - Jean's book seems to costs over £90 now, but it is worth every single penny.  I am pretty sure that early on in Smith's Riccia key the split is whether your specimen looks spongy or not - back in about 1994 I was sure the first Riccia I had come across in Carmarthenshire was R. sorocarpa, and to me it looked 'spongy' ....... I followed the key and think eventually ended up at R. cavernosa - this was clearly wrong and then it occurred to me that the reference to sponge probably meant natural sponge, which is probably unfamiliar to a lot of people today and was a bit of a rarity even when I was a kid in the 1960's (or perhaps it was expensive and we could only afford artificial sponge - actually we had a loofa which tended to take your skin off if you rubbed too hard!) - the only times I seem to see natural sponge these days is in art supply shops (usually as expensive tiny fragments).

Anyway, whilst at Llangorse Lake last week I glanced down and saw what I first took to be a thick layer of algae amongst open vegetation in the inundation zone (the lake level at Llangorse tends to be a lot higher in winter than in the summer months).   On closer examination the 'algae' turned out to be the largest population I have ever seen of what looked to be  R. cavernosa.   I had it in the back of my mind that Sam had recorded cavernosa at Llangorse when he mapped the marginal vegetation several years ago, but on reading his report he in fact had found R. subbifurca and, if Sam accepts the voucher, cavernosa will be a new addition to the Brecks bryophyte flora.

Pics below are a bit poor, but the close-up shows the large perforations on the surface - a bit like an old fashioned sponge.

Saturday, 12 August 2017

Moerckia

Have eventually managed to get back into my Google account ...

Now that autumn has set in (i.e.the swifts have gone), my mind is turning again to bryos.

A recent trip with Jonathan Saville to some sloppy calcareous flushes in the Black Mountains just SE of the Grwyne Reservoir, which we first spotted last winter, proved quite rewarding for vascular plants, with a strong population of Eriophorum latifolium and small pops of Carex lepidocarpa and Carex dioica amongst other things.    One of my main reasons for revisiting was that I hoped to refind Amblyodon dealbatus, which was reported from this area during an NCC survey of the upland vegetation in the 1980s.  No joy with that moss, but a small area less than 0.5m  diameter with some tufa deposition caught my eye and sure enough a small amount of Moerckia flotoviana was present.   I have come across perhaps half a dozen sites for this liverwort scattered across the National Park all as very small populations in similar tufaceous habitat, usually present as a very restricted area in flushes dominated by the likes of Palustriella commutata and Scorpidium species.  Moerckia may prove to be relatively frequent in areas where there has been a lot of lime working, such as the Foel Fawr on Mynydd Du, but it seems amazing that it is able to find and colonise such rare habitat often hidden away in seas of Nardus and Molinia.    

Tuesday, 8 August 2017

Pogonatum urnigerum in lowland Monmouthshire


The recent rainy 'summer' has turned my mind to bryophytes, and I have knocked off a few VC35 tetrads in lunch-breaks and evenings.  This evening I visited SO30T, south of Clytha in the heart of lowland Monmouthshire.  Most of the 60 or so bryophytes were mundane, although I have a few Orthotrichum to check.  However, I was astonished to find a large colony of Pogonatum urnigerum on a cobble-lined bank by a pasture.  This is an uncommon species in the county, although it is widely scattered in the west at ca. 300m altitude.  The only colony in the east is at Trellech Hill Quarry (280m altitude).  The Clytha colony is at just 145m altitude, and is thus in genuinely lowland Monmouthshire.


I've just checked and I notice there are still records listed for Glamorgan that need reallocating to Monmouthshire. Most, if not all are Peter's, but it is probably something Dave Slade can sort out as the records came via SEWBReC. (Barry)

Thursday, 3 August 2017

Something exciting in the Black Mountains

Something a little more exciting than Sphagnum quinqueferium caught my eye during today's Welsh Clearwing surveys in the Black Mountains. A luxuriant 50cm square patch of Antitrichia curtipendula atop a dry stone wall!


The location in SO2627 is about 300m inside VC35. The Atlas shows a pre-1950 dot for SO22. The known site in SO23 (VC42) is around 5km to the north-west of here.

Wednesday, 2 August 2017

Sphagnum quinquefarium in the Black Mountains

I have to confess I've scarcely looked at any bryophytes for a few months, but a pretty pink and green banded Sphagnum caught my eye earlier this week, while I was surveying for Welsh Clearwing moth in the Black Mountains. I hoped this might be Sphagnum russowii, but my samples have three spreading branches per fascicle - so I think this must be S. quinquefarium.
Sphagnum quinquefarium
There was an extensive patch of this moss growing in bilberry heath on a NE-facing slope above the Grwyne Fechan (SO217234). Perhaps not an unusual sight in the Brecon Beacons National Park, but it's the first time I've seen this moss away from woodland.
Sphagnum quinquefarium habitat