Surprising urban wall moss

My most surprising bryo find of the winter so far has been Ptychomitrium polyphyllum growing just a stone's throw from the Butterfly Conservation Wales office in Hafod, Swansea. I first noticed a cushion of this moss growing on the sandstone coping of a sloping wall back in November, but only remembered today to take my camera along to get a few photos. I must have walked past it countless times last year before I noticed it. The moss is in the foreground of the photos below. It is close to a busy road junction and must experience pretty high levels of nitrogen pollution.

I noticed today that as well as the large fruiting cushion there is a small non-fruiting cushion nearby (on the right-hand side in the photo below left).

The associates are all mundane species: mostly Grimmia pulvinata with some Bryum capillare and a tiny amount of Tortula muralis. The rest of the wall is almost devoid of moss apart from a few scraps of G. pulvinata here and there.

I've not seen this moss in an urban situation before, but perhaps it isn't so unusual. Sam's Pembrokeshire flora mentions its persistence on imported rocks at County Hall in Haverfordwest, shwoing it can survive some pollution.

Days in the Black Mountains 3 - Grwyne Fawr

Day 3 was a day for walking rather than mossing, thanks to a blanket of snow covering the Black Mountains.  As the Grwyne Fawr valley had been visited by the BBS in 1999, it seemed a good place for a walk and some poking around, without the need for complete listing.  I failed to relocate the majority of the BBS's best finds, such as Campylostelium saxicola and Scapania subalpina, but there were a few nice surprises.

Flushes above the track held abundant Philonotis calcarea and Palustriella, but plenty of searching failed to produce any Amblyodon (recorded once in the easternmost Blacks); likewise searching the flushed track and stream edges didn't reveal any Haplomitrium (again).  Pseudocrossidium hornschuchianum at 530m altitude was a surprise, as was some Orthotrichum stramineum on a concrete post.  A rock shelf in the river held Schistidium platyphyllum, and I was astonished to spot a colony of Riccia beyrichiana on adjacent thin soil (Tom Blockeel noted this scarce species further down the valley in 1999).

On the way back from the mountains I stopped to record in two fragmentary VC35 tetrads - getting >50 species in both SO22M and SO22R.  Porella arboris-vitae was the highlight in the former square, and Fissidens celticus was a surprise find on an anonymous bank in the latter.  I also stopped at Coed-dias Bridge to check on the Grimmia decipiens colony that was found there by the BBS in 1999.  Only a single cushion remains, at this sole VC35 locus, and copious algal gunk on the bridge parapet suggests that nutrient enrichment and/or increased shade may have caused a decline.

 

My final stop for the day was another site which has been 'done' regularly in the past: Coed-y-Cerrig NNR.  I actively avoided the NNR in the past, focussing my efforts on other parts of the tetrad, but it is now 20 years since Martha Newton's survey and 'Bosanquet's Rule' is that "well-recorded sites will always produce the most exciting new finds".  Sure enough, star find of the day came from a sandstone block ca. 60m from the carpark: three loose cushions of Grimmia hartmanii (new for VC35) growing alongside Plagiomnium cuspidatum.  The frequency of Porella arboris-vitae was nice too, although this species is well-known from Coed-y-Cerrig.

Days in the Black Mountains - 2 Rhos Dirion & Nant Uchaf

A glorious Day 2 in the Black Mountains started and ended with low cloud, but there was bright sunshine in the middle of the day.  I started at Gospel Pass and walked westwards to the crags east of Lord Hereford's Knob.  These and the other north-facing crags have tempted me for ages, so it was exciting finally to visit them.  These first crags were relatively mundane ORS outcrops with base-enrichment: highlights included constant Seligeria recurvata, frequent Orthothecium intricatum, and scattered patches of Lophozia incisa, Bartramia ithyphylla, Pohlia cruda, Scapania aspera (dorsal branching) and Schistidium strictum.  Surprise find of the morning was an extensive colony of Zygodon viridissimus var. viridissimus on ORS at 550m altitude, which beats the Atlas altitude record.

Once the cloud had lifted, I headed over the top of the Knob to an area of base-rich flushes at SO223347, which held Philonotis calcarea, Plagiomnium ellipticum and some excellent female Riccardia incurvata.  My initial plan had been to stick to the ridges, but the unexplored headwaters of the Nant Bwch and Nant Uchaf drew me in.  A Short-eared Owl flew up from Molinia as I walked down into the valley, and I found myself in a wonderful area of scattered trees, tufaceous flushes, frozen waterfalls and ORS boulders.  The bryophyte flora didn't live up to my hopes (I cannot believe there was no Haplomitrium for example), but notable finds included Sphagnum quinquefarium, Leiocolea collaris, Preissia quadrata, Drepanocladus revolvens ss, Scapania scandica and Hyocomium armoricum.

Returning to the tops, I looked at dull blanket bog at 700m altitude on Twyn Talycefn - a single mound of Racomitrium lanuginosum was the highlight - and at the same altitude on Rhos Dirion.  The most remarkable find of the day was the nitrophilous Orthotrichum diaphanum on the Rhos Dirion trig point, at 713m altitude which beats the Atlas record by >150m {I don't want to think about its N source up there}.  For a brief moment the clouds were below me, and I looked west across a sea of cloud to the 'island' of Pen-y-fan.

Looking down from the top, it was obvious that the uppermost crags of Pen Rhos Dirion (700m altitude) hadn't thawed out for weeks.  They were surely the place for something rare... a relatively quick search of a few 10s of metres of the upper crag produced Grimmia torquata new for the Black Mountains, Brachydontium trichodes and Plagiobryum zieri, none of which had been seen on the morning's lower crags.  The big lower outcrops of the Pen Rhos Dirion crag await a return visit, and are likely to be base-rich and interesting.  Perhaps Graham will accompany me for that one...

Days in the Black Mountains - 1 Hatterall Ridge

In contrast to the Brecon Beacons - which Graham and I surveyed systematically in the early/mid 2000s - the Black Mountains are very under-recorded.  They have relatively fewer crags than the Beacons, but those which are present hold some very base-rich rock.  Star species include Seligeria patula and Scapania calcicola on Tarren yr Esgob, an old record of Amblyodon dealbatus, and even a historic claim of Myurella julacea.  We hope to fill in some gaps in recording this year, and I made a start on two days in early-mid January 2018.

My first day was spent in Monmouthshire, where I filled in three marginal tetrads: the fragmentary SO23R and SO32E held fewer than 20 species each, but SO23V was pretty rich, with well over 100 species.  I walked up on to the Hatterall Ridge from the east, between the Red Darren and Black Darren in Herefordshire.  Once on the ridge I marched north to the northernmost point of VC35, which is marked by a tiny cairn.  The northernmost bryophyte in the county turned out to be Rhytidiadelphus squarrosus, and half an hour of combing the dry blanket bog produced just 11 species.  Surprise highlight of the area was a patch of leggy Bilberry at >600m altitude that sported 10+ tufts of Ulota bruchii and a tuft of Orthotrichum pulchellum!

The blanket bog on the Hatterall Ridge is mostly very dry and degraded, but I made a few DAFOR lists as I worked my way south.  Highlights were a 1x1m mound of Sphagnum capillifolium rubellum at SO275311, 10s of square metres of S. cuspidatum and S. papillosum in an area of pools at SO281306, and a few shoots of Cephalozia connivens in the latter area.  Cowberry and Crowberry were prominent features of the area.

A contrast to the blanket bog/moorland was provided by the hillside above Trevelog, at 420-450m altitude; this accounted for the majority of the bryophyte diversity in SO23V.  There were Old Red Sandstone boulders with Ptychomitrium polyphyllum, Seligeria recurvata and Tortella fasciculata, a deep valley with Entosthodon obtusus, Ditrichum gracile, Gymnostomum aeruginosum and abundant Conocephalum salebrosum, and a series of base-rich rills with Philonotis calcarea, Palustriella falcata, Jungermannia exsertifolia, Leiocolea bantriensis, Plagiomnium ellipticum and P. elatum.  Star find was some dense patches of Riccardia incurvata alongside one of the rills, new for the Black Mountains and VC35.

After these riches I reckoned the tetrad was well-covered, so climbed back up to the ridge so as to head southwards to SO32E.  En route I noticed a frozen flush high on the hillside in SO22Z, so headed for it.  My logic was that if a spring/flush was cold enough to be frozen when the rest of the hill had thawed then it should hold something rare.  I followed it upwards, and found two extensive patches of Sphagnum platyphyllum at SO286297 & SO287297 - my logic had proved right!  This was a new species for the Black Mountains and VC35, and is a long way south of its nearest colonies in mid Wales and the Long Mynd.  It was also the most well-marked S. platyphyllum I have ever seen, with large apical buds, pale stems, large stem leaves and regularly monoclade shoots.

SO32E still beckoned, and on my way there I spied another rushy spring on the ridge edge.  This too held Sphagnum platyphyllum at SO297287, as well as S. capillifolium rubellum and S. papillosum.  The final fragmentary tetrad produced 17 species, which was all that could be expected from a few hundred square metres of dry, patch-burnt blanket bog.  All in all it was a good day! 

A few bits and bobs from the Usk

I had a quick walk along the Usk at Abergavenny at lunchtime on Friday and it occurred to me that I hadn’t seen Hennediella stanfordensis for some time.  Water levels were low enough to be able drop down onto rivers edge and peer at the eroding banks.   Bank erosion due to recent winter floods meant that there were relatively few areas with any bryophyte cover and it took me some time to find a few small patches of Hennediella although were some nice colonies of Bryum gemmiferum here and there.    

Not sure I have ever looked at Hennediella under the microscope – the few teeth near the leaf tips are very distinctive.

Male and female Lunularia seem frequent along this part of the Usk – in the past I have kept an eye on mixed patches, but haven’t yet seen any sporophytes.

 

Further upstream past the hospital is a stoney bank where Bryum donianum grows – I am not sure I have ever looked at donianum under the microscope either, so I pulled a couple of leaves off – in the field the thick margin joining the nerve is obvious, but the tiny teeth probably less so.    

Bonus species included a common sandpiper, presumably the same bird I had seen further upstream earlier in the week, a kingfisher and there were also a few snowdrops flowering on a nearby roadside.