01 July 2013

Craig-y-Llyn, Glamorgan vc41

Visited by IK Morgan & RN Stringer, 21.6.2013

The main purpose of the visit was to see whether we could relocate serrated wintergreen Orthilia secunda, last recorded at this locality by AH Trow and JH Salter in 1905. According to the Flora of Glamorgan (Wade et al, 1994: 151) previously, in 1892, Trow had found it at one locality and, on the 1905 visit they found it at a second site at Craig-y-llyn, but with Trow noting in 1911 that the 1892 site was `almost inaccessible now`.

IKM had visited Craig-y-llyn with Julian Woodman in July 1997 to look for Orthilia and other plants, but on that rather cursory visit, Orthilia was not seen (though other species of interest were). The notes relating to Orthilia in The Flora of Co Fermanagh by Ralph Forbes and Robert Northridge, newly published in 2012 acted as a catalyst for IKM to try to search again for Orthilia and it was decided to make Craig-y-llyn the target for one of our weekly botanising visits in June. The excellent `Fermanagh Flora` contains some very comprehensive and useful notes (on pp377-8) regarding the occurrence of the species in that Northern Irish county, saying that it is found `in dense clonal patches….in crevices….on dolomitized sandstone scarps, and scattered in steep submontane, mossy, Calluna-Vaccinium-dominated heathy slopes`. They also remark that `when one has got one`s eye in for it, the rather pale, grey-green, wintergreen, serrated leaves can be picked out amongst other foliage and moss all year round`. It flowers only very sparingly in Co Fermanagh and we can assume the same to apply to the more southerly site at Craig-y-llyn (and Craig Cerrig-gleisiad in Brecs, where it also has been recorded) – so one has to search for the vegetative clonal patches, hidden under Vaccinium or Calluna. As we approached Craig-y-llyn via the track to Llyn Fawr on 21.6.13, we scanned the amphitheatre of cliffs for good rock faces and gullies to search. We had intended to start near the eastern part and work westwards and, accordingly we ascended the steep talus slopes that are covered in dense Vaccinium myrtilus and other vegetation. This climb itself was quite tiring. En route, old empty 2013 `tent nests` of bilberry pug Pasiphila debilata were common in this area of bilberry, most were brown and withered, with the larvae having vacated them, but a few individuals were still to be found, perhaps reflecting the late, delayed season this year. An adult latticed heath Chiasmia clathrata clathrata was also seen, as well as the common beetle Phyllopertha horticula.
 Upon reaching the intended first gully, we realised that what had looked reasonably easy from down by the lake was actually quite difficult. This first gully  (at SN918030) was very floriferous, with flushed areas holding an attractive suite of plants akin to an Alpine meadow, with abundant Geum rivale, Angelica sylvestris, Sanguisorba officinalis, Valerianella officinalis, Succisa pratensis and Tussilago farfara, many of which were in full flower and being visited by bumblebees that included the very local Bombus monticola (as well as the common B. pascuorum). On rockier areas, were strong, flowering plants of Rhodiola rosea and some clubmosses. It was when we started to work our way laterally along the cliff faces that we fully realised how difficult it would be, some sections being relatively easy, but others difficult or dangerous, requiring descents and ascents to avoid steep drops that may not be apparent amongst the deep swathes of Vaccinium. It also proved difficult to climb some sections of actual cliff face to search for Orthilia amongst the Vaccinium. Progress was slow but we worked westwards, passing groups of whitebeams Sorbus porrigentiformis and searching for Orthilia, though again, we could not climb most outcrops above.

After a few hours covering a disappointingly short distance, we decided to call it a day and descended back down to the lake/reservoir. How little we covered was apparent when we looked back at the cliffs, the area being that represented in the accompanying photograph below. We only covered that area of cliff eastwards of the prominent tree on the skyline!
We see no reason why Orthilia does not survive at Craig-y-llyn but it will need perhaps repeated efforts, or collective efforts by groups of fit botanists focusing in on this species. In the days of Trow and Salter, the general area would have been sheep-grazed with only those areas inaccessible to sheep holding luxuriant vegetation, on ledges and the like. Perhaps these botanists were likely to have targeted these ungrazed areas as likely to hold species of interest. The fencing off of the area around the lake many years later, presumably linked to the establishment of the forestry below has resulted in a resurgence of vegetation –itself of great value in our overgrazed uplands (and hence the lovely herbaceous swards on the afore-mentioned flushes), but it does make traversing the area a little more difficult and the locating of Orthilia even more so!
As well as the suggestions given above with regard to locating Orthilia, it may be worth considering a (snow/frost-free) late winter visit, when much of the vegetation has died back and when perhaps its grey-green hue may stand out amongst the darker green bilberry? In June, the bilberry can also look fresh and very slightly glaucous (as well as having finely serrated leaf margins), so beware! Craig-y-llyn is a wonderful place and I`m sure that it will yield other noteworthy natural history records of all taxonomic groups - after adequate searching. Some plants of Dryopteris carthusiana were seen near Llyn Fawr at SN91939 03470.

Forbes, R.S. & Northridge, R.H. (2012) – The Flora of County Fermanagh. National Museums Northern Ireland.
Wade, A.E., Kay Q.O.N. & Ellis, R.G. (1994) – Flora of Glamorgan. The Natural History Museum, London.

I.K. Morgan & R.N. Stringer, June 2013.

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