Tuesday 11 September 2012

A day out in Cwm Penmachno

On Friday I joined Wendy McCarthy and a group of Caernarvonshire botanists for a visit to Cwm Penmachno. Wendy had recorded in this tetrad before, but wanted to take a different route through the quarries and see if there were any interesting plants around a couple of lakes marked on the map.

In the end most of the interest of the day centred on non-flowering plants, beginning with rustyback, Asplenium ceterach, on walls, and then moving through other ferns and also clubmosses (at least one member of the group was also looking at the bryophytes as well). Maidenhair spleenwort, Asplenium trichomanes, has several subspecies; ssp. quadrivalens is typically found on walls where mortar leads to base-rich conditions while ssp. trichomanes is more typical of acidic habitats. We found a putative hybrid between the two, much more vigorous and larger than usual. We also spent some time looking at the male-ferns, Dryopteris spp., in order to identify the different species, including (I think) D. oreades, mountain male-fern, D. affinis, scaly male-fern and D. borreri, Borrer's scaly male-fern. I must admit I am not very confident in the identification of all of these, but one of the benefits of spending a day out with other botanists is always the chance to learn more about the species you encounter and Friday was no exception - especial thanks to Wendy, Martin and Paul.
Maidenhair spleenwort, Asplenium trichomanes - putative hybrid between subspecies?
 We also found two species of clubmoss - the fir clubmoss, Huperzia selago, and stag's-horn clubmoss, Lycopodium clavatum. This was found in some spectacular patches, and also exhibiting the typical forking fertile shoots.
Stag's-horn clubmoss, Lycopodium clavatum
As well as botanical interest, we had some great views, although a brisk wind kept our coats on the sky was clear for much of the day and views down the valley were lovely.
View from the quarry down Cwm Penmachno
 We made our way to this lake hoping to find a range of aquatic plants. Sadly it turned out to be a flooded quarry without much marginal vegetation. However, what it lacked botanically it made up for in scenery, especially with the rocky (and dripping) overhang at one end.
Flooded quarry lake 


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