Friday, September 04, 2015

Cwm Oergwm

The Brecon Beacons summits form a long ridge with steep valleys to the northeast, interspersed with long parallel spurs and four round-headed valleys or cwms; from west to east these are Cwm Sere, Cwm Cynwyn, Cwm Oergwm and Cwm Cwareli.

Cwm Oergwm (Valley of the cold valley) was our object last week but we had to cross the stream from Cwm Cwareli to get there. This seemed a trivial matter when we did the recce in March. But August proved much wetter (particularly the night before our outing) and when we got to the ford it didn't look straightforward to cross at all so some time was spent fruitlessly looking for a better crossing point (and finding some new species to record naturally). So, in the end we returned to the normal fording place and took our boots off to cross carefully by wading.

We then made our way up the valley to the upper reaches of the Nant Menasgin, our main recording area, and previously a place where Bog Orchid has been found.
 Picture by Sue

We spent time down by the stream  as well as above it.

After some recording in the main area we had lunch by the stream
... and watched the bubbles in the water at the base of a cascade:

We explored many varied and species rich flushes near the stream but didn't find any Bog Orchid. Plenty of updated records for the 2020 BSBI Atlas were made though. (We found plenty of Sundew, Butterwort, Skullcap and a host of Rushes and Sedges.)

Heather, Grug or Calluna vulgaris

One flush seemed calcareous and had different species including this (mainly well past it like the example on the left) which had us stumped for awhile...
Marsh Arrowgrass, Saethbennig y gors or Triglochin palustris (Triglochin palustre in older books)

Sue and Meg among the heather.

It was much easier crossing back over the Cwareli stream going back as the water had already abated.

Anthony was the only one properly equipped for the ford as we found it.

The Bog orchid hunt isn't over yet - we didn't get to the very highest parts of the stream near the source and further exploration there next year is planned.

As always I owe thanks to my intrepid co-explorers who supplied knowledge, good company and six extra eyes!

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