Llanelli Naturalists Newsletter - June 1984
R.H. Davies and R.N. Stringer

In the course of our investigations into Carmarthenshire mosses and liverworts we have examined many areas. We would like to take this opportunity to describe one exceptional site. This site is not only important for its bryophytes, but had a large lichen flora-many flowering plants of interest.

Craig y Derwyddon lies north of the Carmel-Llandybie road to the west of the Village of Pantllyn (Grid Ref: SN 605165) and comprises of abandoned limestone and gritstone quarries, spoil heaps, ruined kilns, a small lake and a wet basic pasture. With such an evocative name as Craig y Derwyddon it comes as no surprise that this site has very important historical interest also.

There are two legends recorded linking the area with sleeping heroes. One makes King Arthur the hero but according to Gomer Roberts, this appears to be an early nineteenth century embroidery by Iolo Morgannwg. A more ancient tradition links the area with Owain Llawgoch, possibly the same Owen that is remembered in Llyn Llech Owen although some historians link the latter Owen with the knight of King Arthur's Court. An historical Owen existed as a fourteenth century claimant to the Principality, yet he never set foot in Wales. It is interesting to note that one of the charges of treason brought against Rhys ap Gruffydd of Dinefwr by Henry VIII was that Rhys had likened James V of Scotland to Owain Llawgoch a man who could free his people. The legend tells of an underground cave or room where the sleeping warrior and his see were sleeping in readiness to be awakened at the appointed signal and claim the throne of Britain. This cave was supposedly that of Craig y Derwyddon and the legend was reinforced by the finding of twelve skeletons in a cave in 1813 during blasting operations in the area.

Quarrying in this area ceased in the early 1850's when R.K. Person of Dinefwr erected new kilns at Cilyrychen and began quarrying Craig y Ddinas.

Since then, the rockfaces, spoil heaps and rock platforms have all been colonised and there has now developed a mixed deciduous woodland of Oak Ash and Beech with a well developed shrub layer of hazel. One of the oak trees was found to be over a hundred years old when felled by its owner and the presence of Clematis which is abundant in area was even noted by Walter Davies in as early as 1858. The site therefore is relatively old and together with the presence of sheer rockfaces and uneven stony kerries has led to the occlusion of the area for grazing purposes and this has resulted is a luxurious ground flora.

Species such as Dog's Mercury, Wood Anemone, Sweet Woodruff, Violets, Herb Robert, Primroses, and various grasses indicate its bawe rich nature and this is confirmed by the presence of the two common hard shield ferns and the Harts Tongue ones of the Rusty Back fern were also found and apparently a rare fern has also been found at this locality. Other rarities of the area include Paris quadrifolia Ghost Orchid and Scottish Primrose (the latter three species to be confirmed).

Below the quarry, skirting the main road lies a small oval lake about 100 yds long, 20 yds wide and 2 yds deep. The lake has a small outlet but because of the porosity of the underlying bedrock it dries out in summer but even so, is damp enough to suppert the growth of willows and alders.

The richness of the site has led to the investigation of the area by the Nature Conservancy Council. Dr. R. Woods surveyed the area in December, 1983, and whilst compiling a species list of bryophytes came up with a total of 56 different species. We visited the same area a fortnight after and this total has been increased to 86 species, thus emphasising the importance and diversity of habitats within the locality. Two moss species found are species previously unrecorded in Carmarthenshire and are new county records. Many of the mosses found by us in this area are unusual because they do not normally occur inland over much of Wales due to the nature of the substrate. Their normal habitats are dune slack areas characterised by having a high water table and a pH which is neutral or slightly alkaline. Species sharing such a distribution include Campylium stellatum, Campylium elodes and Trichostomum crispulum. Grassland species found in the open areas of woodland which are also recorded in similar calcareous environments such as sand dune areas (see previous newsletter) include Pseudocler(?) purum, Tortula ruraliformis, Barbula    species Bryum capillare and Dicranium scoparium.

Two species Rhytidiadelphus squarrosus and Rhytidiadelphus triauetrus were also found in Cefn Sidan but they were more abundant in Pant Llyn. One of the most important finds of the area was Thuidium philibertii growing on spoil waste in association with another species of the same genus Thuidium tramariscinumo. The former is a new county record.

The dense bryophyte ground cover extended into the woodland area and the most dominant species encountered here were those of Eurhynchium and Brachythecium species, common species found in such habitats.

Bordering the woodland on the lake edge were found not only hydrophilic/aquatic such as Acrocladium cuspidatum, to Acrocladium cordifolium, Leska polycarpa and Eurhynchium riparoides but an even more important epiphytic community on the willow and alder branches. The high rainfall of the area and the presence of as sheltered lake gives rise to very humid conditions and the luxurious epiphytic flora is unlike any we have found in our bryophyte travels of the county so far. Such species as Hypnum mamillatum, Lejeunea cavifolia, and Lejeunea ulicina were found for the first time by us and these were intermingled with more commoner species such as Hypnum cupressiforme, Ulota crispa, Metzgeria species and the beautiful Frullania dilitata.

This high humidity area contrasted greatly with that of the rock faces which were open to the drying wind and as a result the numbers of species were less and the only of note found included Grimmia apocarpa, Tortula muralis Fissidens cristatus and Encalypta species. The rock faces were however colonised by a healthy lichen community (Dr. Woods recorded over 70 from the area) but where the rock was shaded Neckera species and the calcicole Cteniduim molluscum became dominant. On the seepage areas however the liverwort Pragiohila asplenioides var majus became dominant and it was amazing to find large differences in species composition over such a small change in substrate composition. This was ideally shown at the top of the quarry on a small plateau. Having high rainfall causing nutrient loss and the presence of gorse bushes has induced a high soil acidity and this is reflected in the bryophyte community. Marked calcidity species such as Polystichum, Atrichum and Diplophyllum albicans were abundant and it was near the top of the plateau where Fissidens viridulis var viridulis another county record was found.

The caves in the area were a bit of a disappointment, even though Pellia endivifolia and Conocephalum conicum grew in profusion around the entrances a thorough search failed to yield the Fairy Gold Moss (Schistostega pennata) which Richard Pryce found in a cave in Stradey Woods.

There is at present a conflict of interest as to the future of this area. The landowner Mr. Rhodes has put in an application for a leisure development incorperating 10 or more holiday caravans and a building with four living units together with a reclamation scheme for the grounds. This includes the opening up of the cave systems and perhaps the utilising the rock faces for climbing purposes.

McAlpines, the company which own the adjacent quarry claim not only that they have a lease for the land allowing development in the future but that caving and climbing in the area will prove highly dangerous in view of blasting operations in the existing quarry.

For the moment the planning application is in obeyance until Solicitors can establish the legal position. The West Wales Naturalist Trust are keen to turn this area into a reserve and the Nature Conservancy will be making a thorough survey of the area in the summer. Any help with biological recording will be gratefully appreciated in the area concerned. Please contact Mr. Rhodes the landowner (lives in caravan in field next to lake) for permission of access.

Bibliography

DAVIES W. Llandeilo Vawr and its neighbourhood, past and present. Llandeilo 1858.

ROBERTS G.M. Hanes Plwyf Llandybie Gwasg Coleg Prifysgol Cymru Caerdydd 1939.