Spring meeting 1999: Abergavenny, Gwent

HomeEventsSpring meeting 1999: Abergavenny, Gwent

14 April 1999 - 21 April 1999

Meeting report

The last time that the Society visited this part of Wales was during the 1984 Spring Meeting held at Brecon. Abergavenny is further to the east and whilst most of the excursions were in Breconshire (v.-c.42), we also ventured into Monmouthshire (v.-c.35). The town is convenient for visiting the Black Mountains lying to the north and reaching an altitude of 800m. Like the Brecon Beacons to the west, they are composed of Devonian Old Red Sandstone and can be very base-rich in places. To the southwest lie the Coal Measures of the Welsh valleys, which are overlain by bands of Carboniferous Limestone. These have been heavily quarried in the past and contain an extensive cave system. The final day was spent on the acid conglomerates of the lower Wye Valley.

Our base was Ty’r Morwydd Environmental Study Centre, a converted convent school, which lent an appropriate air of moral seriousness to the week’s activities. The meeting was well attended with 34 staying at the centre over the weekend, and about 44 present in the field, although as usual numbers dwindled towards the end of the week. Thanks to some unseasonable weather, members arriving on the Wednesday were greeted with the beautiful sight of sunlit snow covering the Skirrid and the slopes of the Black Mountains, although the local secretary was rather anxious as an upland excursion had been planned for the next day. Shortly after her arrival, Jean Paton lost no time in finding Syntrichia papillosa (reported as new to v.-c.35 earlier in the year) on an ash trunk in the grounds of Abergavenny Castle.

Thursday 15th April

Although there was still a good deal of snow around, the area of Cwmyoy (v.-c. 35, SO 2923) was clear. We squeezed into the small car park behind the church, and as the sun came out headed uphill to explore the west-facing sandstone cliffs and the extensive area of block scree. We had hoped to relocate Grimmia longirostris on some of the boulders, but despite prolonged search among the dried up cushions of Grimmia pulvinata, Orthotrichum cupulatum, Racomitrium heterostichum, Schistidium apocarpum agg., Ptychomitrium polyphyllum, Zygodon viridissimus var. stirtonii and a perplexing form of Grimmia trichophylla (fruiting), we were disappointed.

The boulders were quite base rich and in places Pterogonium gracile and Scapania aspera were abundant. A few tufts of Didymodon ferrugineus were noted on the tops of some of the boulders shaded by trees, sometimes growing with Porella arboris-vitae. Other liverworts noted in this area include Leiocolea turbinata, Lejeunea lamacerina, Reboulia hemisphaerica, Scapania compacta and Tritomaria quinquidentata. On stony ground at the base of the cliffs there were several patches of Brachythecium glareosum, and higher up the slopes Weissia brachycarpa var. obliqua. The cliffs themselves were rather dry, but there were a few areas of water seepage where we found cushions of Amphidium mougeotii, Didymodon rigidulus, Eucladium verticillatum and Gymnostomum aeruginosum. There were some interesting epiphyte communities, especially on ash and elder in the sheltered areas at the base of the cliffs. Michael Proctor found a large patch of Leucodon sciuroides, and we also noted Cryphaea heteromalla, Orthotrichum lyellii, O. stramineum, Syntrichia laevipila, and Ulota phyllantha. The latter plant has only recently been recorded as new from v.-c.35 and v.-c.36, so it seems to be increasing in the area. Although no great rarities were discovered, we saw 105 mosses and 28 liverworts at a most pleasing locality.

On the way back, we tried to relocate Bryum gemmiparum at a couple of it’s old localities on the river Grwyne near Forest Coal Pit, where it had been seen in the 1950s and 60s. Unfortunately there had been considerable disturbance to the river bank since that time, and we did not find the plant either there or further upstream at Coed-dias, although Seán O’Leary spotted an interesting plant on the bridge here that turned out to be Grimmia decipiens.

Friday 16th April

Most of the day was spent exploring the lower part of the Clydach Gorge NNR (v.-c. 42 SO 2212) where the river Clydach cuts through the Carboniferous Limestone. We parked beside the disused Llanelly quarry, and walked down the steep wooded slope to the river. The limestone boulders beside the track supported a rich growth of calcicolous bryophytes, including Brachythecium glareosum, Scapania aspera, and some luxuriant Taxiphyllum wissgrillii. Zygodon conoideus was fruiting on elder, and a heap of cinders yielded a puzzling Eurhynchium that provoked much debate, but turned out to be E.schleicheri after all. At the bottom of the track Jean Paton confirmed the presence of Plagiochila britannica, and Mark Pool found a large patch of Hypnum lindbergii. At this point Mark Hill, together with Gordon Rothero, plunged down the steep slopes of the lower part of the gorge. He emerged further upstream with records of Campylophyllum calcareum, Platydictya jungermannioides*, and Lophocolea fragrans*. Nowellia curvifolia was present on a number of logs, and Seán O’Leary found Cephalozia lunulifolia*.

We had lunch beside the river close to some low cliffs where Martha Newton pointed out Cololejeunea calcarea. Some more intrepid members managed to cross the river and continued upstream. Orthothecium intricatum was present in some of the limestone crevices, and Gordon Rothero found patches of Marchesinia mackaii*. Others returned to the old quarry, and noted Aloina aloides*, Jungermannia pumila, Leiocolea badensis, Leiocolea turbinata and Scapania compacta.

In the afternoon we visited Landynidr Bridge (v.-c.42 SO1520) and the south bank of the river Usk for about a mile upstream, hoping to relocate the Bryum gemmiparum that had been noted by the BBS in 1984. Unfortunately we were disappointed in this, but we did find Didymodon nicholsonii, D. spadiceus, Leskea polycarpa, Orthotrichum rivulare, Leiocolea alpestris and Plagiochila britannica. Gordon Rothero noted Fissidens exiguus.

Saturday 17th April

Bryologists on their way up Craig Cerrig Gleisiad National Nature Reserve, near Abergavenny

Craig Cerrig Gleisiad NNR (v.-c.42 SN 9621) is a north-facing sandstone Cwm in the Brecon Beacons, that was last visited by the society in 1984. Most people headed straight for the cliffs and worked their way along in scattered groups, exploring the rich bryophyte flora of the rock ledges. It was a good day for lovers of the Bartramiaceae, with B. halleriana, B. ithyphylla, B. pomiformis, together with Plagiopus oederianus all being found in close proximity by Blanka Buryová . Other species from the rock crevices included Amphidium mougeotii, Brachydontium trichodes, Seligeria recurvata and Rhabdoweisia crispata. Some of the area was quite base rich, with large mats of Ctenidium molluscum var. condensatum in the damper areas. There were cushions of Anoectangium aestivum, Grimmia torquata and Gymnostomum aeruginosum in the rock crevices with Bryoerythrophyllum ferruginascens, Plagiobryum zieri, Orthothecium intricatum and fruiting Isopterygiopsis pulchella. Jean Paton homed in on a gemmiferous stem of Leiocolea heterocolpos growing through a cushion of Scapania aspera, and Nick Hodgetts found Scapania aequiloba* and Frullania microphylla var. deciduifolia* in its second British locality. Tom Blockeel vanished up a gully, and was later able to confirm the presence of Eremonotus myriocarpus. Jan Hendey found Racomitrium aquaticum on some exposed rocks.

In the afternoon, various parties split off to visit other localities. Some scrambled up through the gullies and headed over the moorland to Craig y fro (SN9720). The flora is similar here, but Mark Lawley added Seligeria pusilla, Ray Woods Tetrodontium brownianum, and Peter Martin Tortella nitida to the list. Sean O’Leary and others visited a ravine at Storey Arms (SN 990200) and found Jungermannia exsertifolia ssp. cordifolia and Plagiochila punctata. A further party stopped at the ravine of the Gawnant Fawr (SO 003131) and noted Anastrophyllum hellerianum, Sphagnum quinquefarium, and Lophozia sudetica. Close by at the edge of the reservoir, Rod and Vanessa Stern recorded Atrichum crispum. Finally, Harold Whitehouse led a dedicated party to admire and photograph Gymnostomum calcareum growing on tufa at Vaynor (SO 050103), at an old locality of Roy Perry’s, just downhill from a pub.

The day concluded at Ty’r Morwydd with a meeting of Council, whose proceedings were rendered even more eventful than usual by the throwing of a stone through the window (from the outside!).

Sunday 19th April

Permission had been granted by Welsh Water for us to drive up to the Grwyne Fawr Reservoir (v.-c.42 SO2330) deep within the Black Mountains. We spent some time investigating the outcrops of dripping base rich sandstone below the dam. There were large cushions of fruiting Gymnostomum aeruginosum, and Blindia acuta was also plentiful. Graeme Smith found a fine patch of Isopterygiopsis pulchella, and Scapania umbrosa* was present on some of the larger pieces of rock that had fallen to the ground. On the soil nearer the dam were found Bryoerythrophyllum ferruginascens, Entosthodon obtusus, Campyliadelphus chrysophyllus, and Barbilophozia attenuata. Orthotrichum cupulatum var. riparium* was abundant on the dam masonry.

We walked alongside the reservoir to reach the stream inflow and nearby low cliffs at the far end. Tim Blackstock noted Scapania subalpina and Leiocolea bantriensis beside the stream, and Mark Lawley recorded Plagiochila spinulosa. Angela Newton pointed out some good patches of negatively geotropic Tetrodontium brownianum as we sheltered from a hailstorm. This grew in association with Brachydontium trichodes and Seligeria recurvata, and Gordon Rothero also found Campylostelium saxicola. Other plants seen included Drepanocladus cossonii, Mnium marginatum, Mnium stellare, Tortula subulata var. graeffii, Barbilophozia floerkei, Leiocolea alpestris and Scapania scandica.

Some stopped on the way back to explore a ravine at SO 247291. All of us except Tom Blockeel walked past a large patch of Riccia beyrichiana. Picking our way through the macerating sheep corpses that littered the stream, we found a similar flora to that noted earlier in the day, although Didymodon spadiceus, Orthothecium intricatum and Cephalozia lunulifolia were additions. As it was Sunday, a number of the party visited the church at Partrishow, in order to admire the fine pre-reformation rood screen.

Monday 20th April

A much smaller group met to explore the Carboniferous Limestone escarpment and old quarries of Craig y Cilau NNR (v.-c.42 SO1816). The path led past the small raised bog of Wern Ddu (SO 185165) which although common land and degraded by heavy grazing was still of interest. Both Calliergon giganteum and C. stramineum were present, together with Sphagnum flexuosum, Scapania irrigua, and some rather depauperate Polytrichum strictum. Seán O’Leary impressed us with his previously hidden credentials as a freshwater biologist, by finding a water scorpion.

Ron Porley headed straight up to the limestone cliffs, and recorded Seligeria trifaria and Platydictya jungermannioides before leaving early. The majority of the party continued up towards the old quarries along a more gentle path. Scapania aspera and Scleropodium cespitans were present on the boulders, and on the soil between Harold Whitehouse noticed a Funaria that turned out to be F.muhlenbergii. Not for the first time during the meeting, we found ourselves following in the footsteps of E F Warburg, who had visited Craig y Cilau in the course of his work on the apomictic Sorbus spp. He had recorded Bryum mildeanum, but the best candidate for the plant, found in short turf by Mark Pool, turned out to be only B. pseudotriquetrum. Also in the turf, Michael Proctor found Mnium marginatum, and Mark Lawley Fossombromia ? incurva, but unfortunately there was not enough material to make a confident identification.

The limestone of the old quarries was rather hard and dry, but John Blackburn found Seligeria pusilla. On soil near the cave of Eglwys Faen we admired good material of Reboulia hemisphaerica with inflorescences. We also noted Aloina aloides, Brachythecium glareosum, Dicranum bonjeanii, Plagiomnium elatum, Blepharostoma trichophyllum and Leiocolea alpestris. Whilst heading back to the cars we were met by Graham Motley, from CCW Abergavenny, who had found Splachnum sphaericum in a bog above the escarpment.

Tuesday 21st April

The last day was extremely wet and put the dedication of the much-dwindled party of bryologists to the test. We visited two Gwent Nature Trust reserves in the lower Wye Valley, although it was impossible to do them justice given the weather conditions. The first, Prisk Wood (v.-c.35 SO532090) is an area of woodland that has grown up around a complex of small quarries in the acid conglomerate. A magnificent display of bluebells cheered us up almost as much as Mark Pool’s discovery of Lophocolea fragrans that he plucked from a rock crevice beside a stream. Plagiochila britannica and P. spinulosa were noted, and Orthotrichum pulchellum and more Ulota phyllantha were found on elders. Leucobryum juniperoideum was present on the woodland floor.

As we sat in our cars having lunch, the rain pounded against the windows, and we were joined by Peter Martin who had left his warm dry office to join us for the afternoon. We proceeded to the wooded ravine at Llandogo known as Cleddon Shoots (v.-c.35 SO523041) which had previously been visited by the Society in 1968. The stream was so full of water that it was difficult to explore it properly, but we were pleased to note that Jubula hutchinsiae and Fissidens rivularis were still present, and there were good mounds of Hyocomium armoricum. Beside the stream we recorded Plagiothecium laetum, Metzgeria conjugata, Pellia neesiana and Plagiochila spinulosa. Finally, Peter took us a few miles south to Lower Wyndcliff (v.-c.35 ST5297) where the opportunity to pay our respects to bryophytes of such stature as Seligeria campylopoda and Gymnostomum viridulum provided a fitting climax to the week.

Acknowledgements

I am very grateful to Ray Woods for the help he gave in organising the meeting, and for putting the resources of CCW at my disposal. Graham Motley kindly provided maps and lists of interesting species for some of the localities. Welsh Water gave permission for us to use their access road to the Grwyne Fawr Reservoir, and Gwent Nature Trust were happy for us to visit their reserves. Jean Paton kindly advised me on the organisation of the meeting, and scrutinised the draft of this report. My thanks are due to all those who sent in records and to those who verified material. Finally I would like to extend my personal thanks to all who attended the meeting, in the hope that they obtained as much interest and pleasure from it as I did.

Jonathan Sleath

Location:

Abergavenny, Gwent