Friday, 5 July 2013

BSBI AGM Anglesey

I've recently returned from hectic and disorganised foray north for the BSBI AGM. My lack of preparation and planning meant that I was only able to attend a couple of the field excursions. After a lengthy bus journey cumulating in almost missing the excursion coach I finally arrived at the first day's destination: Cors Erddreiniog. This large and varied area of fenland is owned and managed by NRW (formerly CCW). We were met by the long-serving site warden Les Coley and some of his colleagues and split into groups to be shown round the site. 

My group proceeded through the drizzle at the dawdle typical of botanical parties. The marshy ground near our starting point provided immediate interest firstly in the form of Glyceria notata a species that I had previously worried that I was overlooking. Seeing it in situ revealed it as quite distinct from G. fluitans, forming more discrete clumps, its foliage a paler shade of green and its panicles distinctly more diffuse.

Glyceria notata, Cors Erddreiniog, VC 52, June 2013

The next species of interest was the Tufted-sedge, Carex elata. A  local species of fen habitats this member of the C. nigra group stands out due to its tufted habit, large inflorescences and small bracts.

Carex elata, Cors Erddreiniog, VC 52, June 2013

Potamogeton coloratus appeared next. Initially resembling P. polygonifolius until the broad leaves, held to the light, revealed their strong net-venation. This very local species of strongly calcareous waters was first  recognised as distinct from P. natans in the UK by Charles Babington on the Channel Islands in 1839  (Preston, 1995).

Potamogeton coloratus,
Cors Erddreiniog, VC 52, June 2013

After roughly an hour wandering through marshy fen-meadow we arrived at the promised Schoenus flushes. Immediately evident were myriad Dactylorhiza all of which resembled, to varying extents, the fen species D. traunsteinerioides. Some were very typical of the taxon with thin unspotted leaves and sparse asymmetrical heads while others were more stout and symmetrical. While I generally have little time for Dactylorchids the more typical of these specimens were very different from other marsh orchids I've encountered.

Dactylorhiza traunsteinerioides,
 Cors Erddreiniog, VC 52, June 2013

After a brief and midge infested lunch unimproved by the claimed anti-midge properties of crushed Myrica we hopped across Carex elata tussocks toward the day's holy grail. Ophrys insectifera growing, unusually for UK populations, on Molinia tussocks in marl fen. The diminutive plants had recently come into flower and were marked with small red flags making their discovery unchallenging. Despite the literal red flags the size of the group still made it difficult to limit the trampling threat from a enthused crowd of botanists. By this point my camera had taken offence at the conditions making photography difficult through the fogged lens.  

Ophrys insectifera,
Cors Erddreiniog, VC 52, June 2013

As rain began to take its toll on morale we snaked our way around the tempting shelter of a hazel wood. Luckily our interest was held by a small population of Eriophorum latifolium. Appearing remarkably like a strange lilly the drooping, nascent flowers stood out clearly from adjacent E. angustifolium.     

Eriophorum latifolium, Cors Erddreiniog, VC 52, June 2013

A wander through an area of previously improved grassland now stripped down to the underlying marl as part of a fen regeneration experiment was followed by an encounter with a species I had entirely forgotten existed. Hottonia palustris grew among tall sedges in an inundated area intermingled with Cardamine pratensis, a species to which it bears a passing resemblance.  

Hottonia palustris,
Cors Erddreiniog, VC 52, June 2013

The second day began in the dunes at Aberffraw where the plants had advanced considerably since my previous visit. While the pace of the walk was somewhat unconducive to serious botany a number of nice species were still observed. An abundance of Ophrys apifera in their prime grew with plentiful Dactylorhiza purpurella and a scattering of probable hybrids with one of the diploid Dactylorhiza species.

Ophrys apifera,
Aberffraw, VC 52, June 2013

Dactylorhiza x formosa, OR D. x venusta
Aberffraw, VC 52, June 2013

Stabilised  grassland overlying small rocky outcrops at the back of the dunes provided plentiful Botrychium lunaria. Finding the first individual required a short search but it was soon discovered in abundance making it  difficult to look closely at one without inadvertently crushing others adjacent.  

Botrychium lunaria,
Aberffraw, VC 52, June 2013

After lunch a move to South Stack was accompanied by an improvement in weather and an efficient viewing of the two specialities of the site. Firstly the local endemic subspecies Tephroseris integrifolia subsp. maritima growing abundantly on the steep slope between the shear cliff and the more gentle grass atop the cliff. Nigel Brown provided able leadership and an interesting ecological observation on the species from the book of the week: Hugh Davies' 1813 Welsh Botanology, a very early county flora. Davies observes 

'There is something singular about the particular attachment of this plant to its maritime situation; although it must for ages have annually ripened its seeds, on the south west side of this country, from which point the wind blows about three-fourths of the year, and must consequently convey the downy seeds plentifully into the country, yet we never see a plant of it, at any distance from its favoured ground, though there is a good deal of uncultivated land near, where it might be propagated without interruption.'  

This observation holds true to this day making this subspecies very ecologically distinct from our subsp. integrifolia that mostly occurs on downland in the south of England. However this species is part of a large continental complex the taxonomy of which has not been properly revised.    

Tephroseris integrifolia subsp. maritima,
South Stack, VC 52, June 2013

A short walk across the rocky heath lead us to Tuberaria guttata. This tiny little plant is one of the specialities of Anglesey and, strangely, a species I had not previously encountered. Being a dull afternoon the flowers were not open but it was still exciting. Such a small and specialised plant is always good to see in its niche as it allows one to bring the species to mind in other suitable sites in the future.     

Tuberaria guttata, South Stack, VC 52, June 2013
Davies, Hugh. (1813). Welsh Botanology
Preston, C.D. (1995). Pondweeds of Great Britain and Ireland (BSBI Handbook No. 8). BSBI publications, London, 1995.

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