04 July 2013

Usk Reservoir

Went last week with Nigel Stringer to look at the Carmarthenshire (N) side of this upland reservoir. It was nice to see the open areas within the surrounding woodland so floriferous as sheep are excluded. The underlying rock is the relatively (in a Welsh context) base-rich Old Red Sandstone and it was good to see, for example, well-grown plants of Alchemilla glauca and Trifolium medium amongst many others, with bumblebees again including the scarce upland Bombus monticola (which was also seen the previous week at Craig y Llyn in Glamorgan). We also saw the shingle specialist 5-spot ladybird at the lake margin.
One plant caught our eye - the narrow-leaved form of Heracleum sphondylium (hogweed) - listed as forma angustisectum in Arthur Chater`s unbeatable Flora of Cardiganshire, but also known as var. angustifolium.  It was frequent along a considerable length of track on the north side of the lake. Barry Stewart actually also reported this taxon in an earlier `Gower Wildlife` posting on 22 August 2011, after he`d found it at Bach y Cwm, along the Afon Clydach. Interestingly, Arthur Chater notes that JH Salter remarked that he`d found it at three sites " in the mountains usually in moist, sheltered gulleys". I recall a sighting of this form alongside the Tywi about 20 years ago (various `upland `plants get carried downstream) and I seem to remember that I`ve had it somewhere too - but without the tiresome task of checking my paper records, I can`t say where! I wonder if Salter is right, and this form of hogweed is more prevelant in the uplands?
Talking of uplands and floral diversity Mynydd Myddfai, which is immediately north of the Usk Resevoir, would have been the stamping ground of the `Myddygon Myddfai` or the `Physicians of Myddfai` - medieval medicine men who often used herbal remedies and who are also associated with Llyn y Fan Fach and its plant-rich crags. Many plants are listed in their medicinal glossaries and place names near the reservoir include `Pant y Meddygon`. Perhaps it was here they collected some plants in the days when cattle rather than sheep grazed the uplands - the Welsh for shepherd is actually `bugail` ie `cowherd`- but now the hill pastures are sheep-shaven and mostly monotonous. Also gone, seemingly, are the small white orchids Pseudorchis albida found by HH Knight in the same area in 1908.
Would n`t it make a good project to reduce the grazing intensity of sheep on this relatively small upland of Mynydd Myddfai north of the Usk Reservoir, with its connections with Welsh culture and great biodiversity potential? Now, that`s an idea for the National Park authorities!
                                         Above: narrow-leaved form of hogweed.

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