Flat Holm Island (summer)

I’ve been out to Flat Holm lots of times, firstly volunteering as an enthusiastic  17 year old, then following that whenever I had the chance. It is a fascinating place, packed with history and lots of gulls too. According to the information there are 20,000 nesting pairs, all toing and froing from ‘chippy ally’ in Cardiff back out to the island.

The grand total of bryophytes recorded on Flat Holm was, until recently one…or maybe it was two, either way I felt confident that even I could make a useful contribution. So I jumped at the chance to go with SEWBREC for their BioBlitz back in August 2017. 

The islands varied past land use means there is plenty of hard-core paths, tarmac, derelict buildings, concrete and limestone block structures, but there are very few – well almost no, natural water features. I have found only one persistent ‘drip’ that lasts year round, in the appropriately, if not enthusiastically  named ‘dripping cove’, where with some luck you will also find a small patch of Eucladium verticillatum hanging onto the underside of the cliff face. The very overgrown WWII defence ditch around the lighthouse also provides one of the few sheltered spots on the island capable of producing any humidity, and the limestone/soil banks are home to plenty of Fissidens taxifolius var. taxifolius and the trees and shrubs ideal habitats for any epiphytes. I’m sure that there is plenty more to find in the right season or with an expert eye, but until then here are the limited ‘highlights’ of the summertime trip;

Brachythecium populem, Barbula unguiculata, Bryum argenteum, Eucladium verticillatum, Fissidens taxifolius var. taxifolius, Hypnum lacunosum, Kindbergia praelonga, Metzgeria furcate, Orthotrichum diaphanum, Plagiomnium affine, Rhynchostegiella tenella, Rhynchostegium megapolitanum, Syntrichia ruralis subs. ruralis, Tortula moralis, Trichostomum brachydontium and Wessia brachcarpa var oliqua.

As always I was very grateful for Georges and Sam’s help with confirming some of the IDs and pointing out where I had gone hopelessly wrong,  it really is the only way to learn when you are starting out – so hats off to them again. New years resolution is to be able to confidently record in a local area without making too many mistakes.........



One small area of Eucladium verticillatum forming near a persistent drip in the 'Dripping cove'.





Flat Holm Island (image copyright of RCAHMW)









Barry in Barry

A walk out to the lighthouse on Barry's west breakwater in yesterday's murky conditions gave the opportunity to make a list of bryophytes on what must be a regularly storm-battered and salt-sprayed pier. Given the exposure, I was pleasantly surprised to record about 25 species, the most unexpected of which turned out to be Didymodon umbrosus, found unusually well-grown near the end of the pier at ST124665. Assuming I have the identification right, this is only the 3rd Glamorgan (4th? Welsh) record, but at what would seem to be a most unlikely location, growing on gritty soil gaps in the stones as shown by the arrow above. Direct associates growing with D. umbrosus, shown in the image below, include D. tophaceus, D. insulanus, Bryum dichotomum plus Amblystegium serpens var. serpens and Trichostomum crispulum were also noted with it in the field.

Note patent leaves bent out from hyaline sheaths with very narrow marginal cells. Also bistratose mid-leaf margins extending to a blunt, flat leaf tip

D. umbrosus & Trichostomum crispulum at same magnification

Adjacent to the breakwater, the tufa cliffs in Jackson Bay ST120666, which extend almost all the way along the east cliff of Nell's Point, held abundant Adiantum capillus-veneris and Eucladium verticilatum. This area looks good for Southbya, but my casual inspections during our walk failed to spot any. I'm not sure how well these cliffs have been searched by Gareth, George or others, but the cliffs would seem worthy of closer inspection should anyone find a bit spare time and they're down that way.

Oxwich Wood cliff

The western half of the cliff, with one of the gigantic boulders from the recent rock-fall at the extreme left.
The scrubbed section at the base of the cliff held most of the interest.

Last week I spent a couple of hours looking at the north-east-facing cliff of Oxwich headland, that overlooks Oxwich Bay. There were plenty of expected calcicoles of interest, including plenty of tufa-forming Eucladium, but no real surprises,. I need to take another look at some speculative Oxyrrhynchium schleicheri, but otherwise the most interesting species of note was Plagiochila britannica, which was growing quite luxuriantly in shaded sections of damp drippy cliff.

 Plagiochila britannica & Eucladium verticilatum

Eucladium verticilatum

 The far section of new cliff created by the rock fall a couple of winters back

I must admit being a bit nervy looking at the base of this section!

Cobalt Crust Pulcherricium  (=Terana) caeruleum

Radyr Quarry

I only became aware of the existence of Radyr Quarry thanks to to three bryophyte records made by A.E.Wade in 1950. Despite being close to home the quarry is completely hidden in trees and scrub, and doesn't stand out on my Explorer OS Map. After a bit of online research I discovered it was quarried for Radyr Stone from the 1800s until around 1920, after which it was used as a refuse tip.

Yesterday lunchtime I visited the southern end of the quarry (ST139794) and was pleasantly surprised by the diversity of bryophytes on the very shady rock faces. Radyr Stone is a breccia, comprising Triassic red sandstone with embedded fragments of Carboniferous Limestone. Given this one would  expect the flora to be calcicolous, and this proved to be the case. A single large tufaceous patch was covered in Eucladium verticillatum (photo below).

Not far away there were several patches of Leiocolea turbinata on soil-capped ledges (photo below), a new species for me. I think both this species and the Eucladium are new for ST17.

The quarry extends a fair way to the north, where it can be accessed via a LNR in Radyr (probably easier than the scramble through brambles at the southern end). I'll certainly check out the rest of it at some stage.

Incidentally, the three species Wade recorded were Riccardia chamedryfolia, Tortula modica and Microbryum davallianum. There is probably no suitable habitat remaining for the latter two species, which shows how much the quarry has changed in the last 65 years.