Merioneth Naturalists: Nant Pasgan (SH63N) John Hughes

June 19 2012

Present: Andrew Graham, Rod Gritten, John Hughes, Jenny Lees, Sarah Stille

Nant Pasgan Mawr
David M Jones

In another wet month for VC48 [235.8mm at Llanymawddwy by 19/6], five of us met at Llandecwyn [Cilfor] to share cars for the trip up to Nant Pasgan. It was the sort of day where the weather could have gone either way. Low cloud, a cold north wind and warm clothes to start with. By mid-morning, however, the whole bulk of Manod was clear, Moelwyn by midday and Yr Wyddfa itself by mid-afternoon. So we were again lucky with the weather and had a marvellous sunny day out on the northern slopes of the Rhinogydd.

Myrica gale
thanks to John Crellin

The first port of call was the flat, wet ground by the old mine buildings just east of Coed Caerwych. Here, many of the chacteristic plants of the day were evident: plentiful Myrica gale, Bog Myrtle, with Menyanthes trifoliata, Bogbean, Angelica sylvestris, Wild Angelica, Narthecium ossifragum, Bog Asphodel,  and other wetland specialists, though we did not come across either Scutellaria, Skullcaps, here or elsewhere during the day. On the path up to Hendre Cerrig there was Vulpia bromoides, Squirrel-tail Fescue, and Aphanes australis, Slender Parsley-piert, with its oblong stipule lobes [triangular in A.arvensis].

There were plenty of good flushes to search for Carex species and we got a good haul, although it was not quite base-rich enough for Carex dioica, Dioecious Sedge. Both Carex hostiana, Tawny Sedge, and C.demissa, Common Yellow Sedge, were present in plenty. There was some optimism about finding their cross, C. x fulva, but the wiser heads in the company determined that it was too early in the season to be confident because the young fruits of  C.hostiana had not matured sufficiently to distinguish them from the ‘squeezable’ fruits of the hybrid. In the ‘quite frequent but easy to overlook’ category Isolepis setacea, Bristle Club Rush, was a good find.

The green lane from Nant Pasgan Bach
Barmouth Walking Festival

We had lunch just to the east of Nant Pasgan Mawr, in whose small abandoned garden was Levisticum officinale, Lovage, [presumably planted] and Carex pilulifera, Pill Sedge. After lunch it warmed up considerably and we headed off in the direction of  Llyn Llenyrch. The Small Pearl-bordered Fritillaries were plentiful in the sun as was their larval food plant, Viola palustris. We were able to compare subsp.juressi with the commoner subsp. palustris, the hairy petioles of the former showing clearly in the sun even without the use of a magnifying lens. We also had time to determine Anagallis tenella in its vegetative state and to distinguish it from the superficially similar Epilobium brunnescens. Both root at the nodes and have paired leaves: these have stomata on both sides in the former, which is hairless. In the Epilobium, which is often purplish and has two lines of minute hairs on the stem, the stomata are above only. Thank goodness for 'Poland'*!

In the event, we decided to turn back before reaching Llyn Llenyrch, to have time to look at the very different habitat of  Coed Caerwych. In the moistness of the wood there was luxuriant Phegopteris connectilis, Beech Fern, as well as fine ‘shuttlecocks’ of Dryopteris affinis, Scaly Male-ferns. As we were returning to the cars for the many-gated drive back to Llandecwyn, we finally saw Melampyrum pratense, Common Cow-wheat, although Ceratocapnos claviculata, Climbing Corydalis, continued to elude us.

The 147 species we saw made for a comprehensive list, albeit without any particular ‘rarities’ on it. Apart from the sun, the views and the Small Pearl-bordered Fritillaries, the main non-botanical delights were the Cuckoo and the frequent sight and rich sound of Tree Pipits parachuting down to earth.

*Poland, John and Clements, Eric J. 2009, The Vegetative Key to the British Flora