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Llanelli Naturalists Newsletter - December 2003 - No 70
Andrew Stevens

Leader Andrew Stevens

Members met on the roadside above the farm on a beautiful hot afternoon where its position on the Farewell Rock escarpment afforded fine views over the coalfield-valley of the Gwendraeth Fawr to the south. While waiting for late arrivals there was a chance to examine the vegetation of the dry, acid roadside bank which included Sheep’s-bit (Jasione montana) and Bell Heather (Erica cinerea).

Hosts, Sue and Tony Mathews, joined us and the party moved off northward, across the road and along a farm track, bounded on one side by a hedge and ditch, and with semi-improved pasture on the other. The track had been extended recently to give access to a large enclosure added to the farm earlier in the year using brought-in rock-fill from a site near Carmarthen. Pausing at the end of the track we were able to view the newly acquired land which occupied a gently sloping hollow bisected by the Nant Berem.  Beyond, the sandstone dip-slope of the Basal Grits of the Millstone Grit Series formed the slope to the north.

The hollow is filled with boulder clay and isolated pockets of peat giving rise to a matrix of wet rush-pasture dominated by Soft Rush (Juncus effusus), Greater Bird’s foot trefoil (Lotus pedunculatus) and Tufted Hair Grass (Deschampsia cespitosa). The vegetation was very rank, the result of low stocking rates and the impossibility of cutting in most seasons, so the going was tough and every advantage was taken of island hopping  from one  drier patch to another. These areas  supported a shorter heathy type of vegetation which included Devil’s-bit Scabious (Succisa pratensis), Sheep’s Fescue (Festuca ovina), Common Cat’s-ear (Hypochaeris radicata), Heath Woodrush (Luzula multiflora), Heath Milkwort (Polygala serpllifolia) and Heather (Calluna vulgaris).  Species in more flushed ground included Heath Spotted Orchid (Dactylorhiza maculata ssp. ericetorum), Star Sedge (Carex echinata) and Cross-leaved Heath (Erica tetralix).  Approaching the stream, the land became uniformly wetter and accompanying the ubiquitous rushes was Marsh Marigold (Caltha palustris), Lady’s-smock (Cardamine pratensis), Marsh Violet (Viola palustris), Marsh Ragwort (Senecio aquaticus), Wild Angelica (Angelica sylvestris) and Lesser Spearwort (Ranunculus flammula).

The banks of the stream were more open with  Brooklime (Veronica beccabunga), Bog Stitchwort (Stellaria uliginosa) and Common Valerian (Valeriana officinalis) most obvious, and it was a relief to reach easier walking on the opposite side. The meadow here was markedly different being relatively short and growing on a more peaty soil.  There was a fascinating assemblage of plants including extensive stands of Bog Asphodel (Narthecium ossifragum), Bog Pimpernel (Anagallis tenella), Hare’s-tail Cotton-grass (Eriophorum vaginatum), Flea Sedge (Carex pulicaris) and Meadow Thistle (Cirsium dissectum), with occasional Selfheal (Prunella vulgaris) and Saw-wort (Serratula tinctoria).  Also notable was the large number of plants of Tawny Sedge (Carex hostiana) and the sterile hybrid (Carex x fulva) between this and Common Yellow-sedge (C. viridula ssp. oedocarpa).  Taken together, the vegetation appears to indicate flushing with base rich water, possibly originating from the limestone to the north or from lime-rich boulder clay derived from the limestone.

The group returned to the opposite bank once again by means of a derelict hedge-bank following the line of a minor geological fault and clearly demarcating the end of the flushed soil as it gave way once again to rush dominated pasture. The bank itself was interesting as the leached, acid soil and better drainage allowed Hard Fern (Blechnum spicant), Heather and Foxglove (Digitalis purpurea) to thrive.  Adjacent ditches from which the banks were raised seemed to be ineffective at moving water but provided yet another variant of marshy grassland.  Here there were Sneezewort (Achillea ptarmica), Marsh Pennywort (Hydrocotyle vulgaris), Square-stemmed St.John’s-wort (Hypericum tetrapterum), Water Mint (Mentha aquatica) and Ragged Robin (Lychnis flos-cuculi).

An arduous trek through dense rush then followed in order to reach a neighbour’s field but was notable for the insects seen which included Ringlet (Aphantopus hyperantus), Small Skipper (Thymelicus sylvestris),  Garden Tiger (Arctia caja) and Small Tortoiseshell (Nymphalis polychloris). 

Once again we were privileged to see a very fine piece of unimproved land with an interesting assemblage of wetland plants.  The Nant Berem appeared to rise in this area with surface  seepage evident despite the prolonged period of dry weather.  It was characterised by low growing wet-heath species such as bog-moss (Sphagnum spp.), Cross–leaved Heath (Erica tetralix), Round-leaved Sundew (Drosera rotundifolia), Heath Rush (Juncus sqarrosus), Bulbous Rush (J. bulbosus), Bog Pimpernel, Flea Sedge, Star Sedge, Carnation Sedge (Carex panicea) and Deer-grass (Trichophorum cespitosum). Other species included Devil’s-bit Scabious and Goat Willow (Salix caprea) with stunted Bogbean (Menyanthes trifoliata) quite frequent. Unfortunately, only a few of the party saw Cranberry (Vaccinium oxycoccos), which at the time of the visit was in fruit.

Returning along the track we made a detour to examine a piece of rhos pasture where goats were tethered.  The grassy areas had a massed display of Whorled Caraway (Carum verticillatum) with Betony (Stachys officinalis), Selfheal, Oval Sedge (Carex ovalis) and Burnet Saxifrage (Pimpinella saxifraga).  A small grove of oak and blackthorn in the middle of the field held a surprise in the form of a small patch of Adder’s-tongue fern (Ophioglossum vulgatum), while on the bank just below had an abundance of Bog Asphodel and Carex x fulva in the wetter parts with a variety of brambles, including the sub-erect type, Rubus plicatus, where the soil was drier. Returning to our cars there was time to reflect on what a brilliant afternoon it had been, how much we had seen and to thank Tony and Sue for allowing us to share it.