Rhossili Down

Tortula wilsonii (tbc) was the highlight of a wander around the n.w. section of Rhossili Down yesterday. It was growing as a few discrete, but dense patches totaling c.3 sqcm on soil ledges on a Brownstones Formation outcrop, Gower's oldest (Silurian) rocks SS41729038. Immediate soil associates included Sedum anglicum, Thymus polytrichus, Hypnum cupressiforme var. resupinatum, Trichostomum brachydontium, Pseudephemerum nitidum, Ceratodon purpureum, Cladonia sp. & Lepraria sp.

The same ledges held a few patches of Campylopus fragilis, at what is only the second site for Glamorgan.

Another Glamorgan first was Philonotis arnellii (tbc), which occurred as thinly scattered shoots on the steep mossy bank below Gorse and Bramble scrub, adjacent to the footpath at the base of the hill SS41649051. This is the site where I previously found Fissidens curvatus, which I failed to refind yesterday. Associates included Fissidens bryoides, Amblystegium serpens, Mnium hornum, Kindbergia praelonga, Richardia chamaedryfolia, Lophocolea bidentata & Weissia perssonii.

A small outcrop at the same location held Pterogonium gracile with Riccia subbifurca on the overlying thin soil crust. Anther colony of the Riccia was found higher up the hill on an ant hill.

All in all, it was a good afternoon, with a bonus ring Ouzel to boot (though not the views enjoyed by Charles & Hilary and Cwm Ivy the week before). The walk off the hill, following the stream below three spring heads, which held Sphagnum denticulatum & subnitens, plus Bryum alpinum & Sarmentypnum exannulatum, added some useful tetrad records that included Hookeria lucens, Plagiothecium denticulatum, Scpania undulata, Pellia neesiana, Campylium stellatum & Oxyrrhynchium speciosum.