Caerau Road Cutting ST135748

Every time I head into Cardiff on the western access road I tell myself, one day I must stop and look at the road cutting flora. The sparse vascular plant cover and abundant bryophytes on the eroding banks always looks promising. Yesterday I was nearby with a spare couple of hours, so I parked in Caerau and climbed over the fence.

For ref the BGS website shows the geology to be a combination of Blue Anchor Formation and Mercia Mudstone Group, these Triassic deposits exposed by the A4232 cutting. The lack of any top dressing has allowed an interesting assemblage of 26+ terricolous species to colonise. Hypnum cupressiforme var. lacunosum, Ctenidium molluscum (only on the S.E. side of the road) Fissidens adianthoides and Trichostomum crispulum were all abundant, with other frequent species noted including Aloina aloides, Dicranella varia, Didymodon acutus, Didymodon ferrugineus and Homalothecium lutescens.

Didymodon acutus

Didymodon ferrugineus

Didymodon ferrugineus

The central reservation and verge 'dirt zone' held locally abundant Didymodon australasiae and occasional Weissia controversa var. densifolia was noted under the crash barriers.

Didymodon australasiae

Didymodon icmadophilus in the Neath Valley

I've not yet checked my specimen under the microscope, but what I've been calling D. icmadophilus (as recommended by Tom Blockeel) was present in good quantity on wavy concrete-block paving at Aberpergwm.  I'm not quite sure what is happening taxonomically with acutus and icmadophilus, as the map on the NBN appears to show records for these taxa amalgamated under the latter name.  If any anyone can shed any light on what's going on I'd be grateful, just so I can enter my records under the correct name.  D. acutus at Merthyr Mawr to me looks quite different to D. icmadophilus I've seen at anthropogenic sites in West Glamorgan.

For ref,  the list of associates on the blockwork was as follows:

Barbula convoluta var. convoluta Barbula convoluta var. sardoa Barbula unguiculata Bryoerythrophyllum ferruginascens Bryum capillare Bryum dichotomum Bryum pallens Bryum pallescens Calliergonella cuspidata Cephaloziella cf. hampeana Ceratodon purpureus Dicranella varia Didymodon cf. australasiae Didymodon fallax Didymodon ferrugineus Didymodon icmadophilus Didymodon insulanus Encalypta streptocarpa Hypnum cupressiforme var. cupressiforme Pseudocrossidium hornschuchianum Trichostomum crispulum

Slim pickings in the Vale

Parts of the Vale are still chronically under-recorded for bryophytes. The latest VC41 tetrad map shows a particularly bad white hole in SS97 and ST07:

Looking at the OS maps and aerial photos for some of these unrecorded tetrads it became obvious why no bryologists had bothered to record there - a mix of improved grassland and large arable fields, with a few lanes passing through and a distinct lack of woodland. Challenging territory indeed, but feeling rusty after the summer hiatus it seemed a good place to kick off the bryophyte recording season when I had a day off work last week. Not too many species to tax my brain.

I visited three tetrads on a day of sunshine and showers, with some lengthy downpours meaning time was lost while sheltering in the car. I started off at Llysworney, which had a bit more habitat variety than some of the other areas thanks to the village streets and walls, and Worney Wood - a new wood planted by the Woodland Trust. The woodland would presumably have been a couple of boring rye grass fields until it was planted a few years ago. Now it supports young trees quite rich in epiphytes, though with nothing of note except for some Porella platyphylla and Didymodon sinuosus on an old field boundary Ash. Tetrad SS97S has now moved along from 3 to 37 bryophyte species.

Much of the day was spent walking the lanes and footpaths in SS97R, which at least succeeded in putting this tetrad on the bryological map with 49 taxa recorded. It was a bit of s struggle though. The arable fields had been recently sown with winter cereals, but a sample collected from a small area of unploughed margin produced three tuberous Bryum species: B. rubens (large knobbly red tubers), B. ruderale (large tubers & papillose violet rhizoids) and B. violaceum (smaller tubers & smooth violet rhizoids - photo below).

To end the day there was time for a brief stop at Llanmihangel churchyard before the heavens opened again. This small churchyard, tucked into a valley bottom, proved to be the nicest spot of the day, and produced a few species not seen at the earlier sites: Cirriphyllum crassinervium, Lophocolea bidentata, Thuidium tamariscinum and Plagiochila asplenioides (the latter growing on a stone grave). SS97V was another tetrad that hadn't been recorded previously, so all 20 species were new.

A feature of the day was the abundance of Anomodon viticulosus on laneside walls and a few hedgerow tree bases. This species is proving frequent in the lime-rich Vale and I look forward to putting more dots on the map on future visits.

I enjoyed the day despite making only 128 bryophyte records and failing to take any tetrads past the 60 mark. No doubt a spring visit would add a few more Orthotrichum, Ulota, etc, but is it worth the effort? I think the time would probably be better spent elsewhere.

D'Arcy Didymodon diversity

A 30-40 minute stop to check out a patch of 'wasteground' by D'Arcy Business Centre yesterday revealed a rich diversity of Didymodon spp., those recorded being fallax, ferrugineus, luridus, tophaceus, umbrosus (below, photos 1 & 2) plus what might be icmadophilus, which will be the first time I've seen it away from the Gorseinon area if confirmed. There was also some Pellia endiviifolia which was fruiting in patches denser than I recall seeing before (photo 3) and a little Bryoerythrophyllum ferruginescens. No Funaria was seen! Vascular plant interest was provided by a strong colony of 300+ seedlings of what could be Filago vulgaris (photos 5 & 6), though needs checking in Poland and/or by growing on my specimen - unless anyone knows this species at this age?

Sychryd scramble

On the 20th a climb up through the complex of boulders and falls along the Glamorgan side of the Sychryd boosted the totals for SN90D from 90 to 159 and SN90E from 41 to 106. Highlights from the limestone section included scattered colonies of Cololejeunea calcarea (photo 1 below), Neckera crispa (just one small tuft noted), Oxyrrhynchium schleicheri (one small colony), Rhynchostegiella teneriffae (sheets of it above water line, photo 2), Seligeria acutifolia (small amounts at 2 locations, photo 3), S. donniana (only 1 fruiting patch seen,, photo 4), Taxiphyllum wissgrillii (1 patch noted on a small embedded rock) & a little Dermatocarpon miniatum (photo 5).

A couple of logs in the higher acid section of the gorge supported species including Barbilophozia attenuata, Blepharostoma trichophyllum, Cephalozia catenulata (photo 1 below), Dicranodontium denudatum & Riccardia palmata, plus there were a couple of nice patches of Hymenophyllum tunbridgense half way up the valley side.

Of note for the wrong reason was a single 10cm x 10cm patch of Lophocolea semiteres established on the track as you walk down the north side of Dinas Rock.

Earlier in the day on the way up the Neath Valley, three lay-by stops along the A465 all showed that the putative Didymodon australasiae is a well established component of the verge dirt zone along this road. A little Ephemerum minutissimum was also collected and checked under microscope at one of the stops.

Didymodon cf. australasiae update

Didymodon cf. australasiae 'dirt zone' habitat

I've been back to Dafen and noted the putative Didymodon australasiae was locally frequent in the 'dirt zone' of the road verge, the population appearing in patches (some very extensive) for over 1 km of the A4138. Yesterday I pulled into the lay-by of the Loughor bypass section of the A484 (Glamorgan) and walked back to a suitable looking dirty verge at SS56359793. Sure enough there was a good scattering of the same taxon. To assist potential searches the following pointers and photos should help build a search image:

• Forms mid-dark green patches, darker than frequently associated Barbula spp. and lacks brownish tones of D. tophaceus and orange tones of D. fallax.
• Grows both as mono-specific turf and as occasional shoots mixed with other spp.
• Leaves spreading-patent, tapering, the tip sometimes appearing pinched towards to a moderately cuculate tip.
• Some plants have broader leaves and the pinched leaf tip is more evident, these may be younger plants?
• The strong nerve is very evident on the upper surface of the leaf in certain light.
• Contrary to my earlier comments the species does crisp up a bit when dry as shown below.

It seems reasonable to suspect this species might be frequent in and around the Swansea-Llanelli area and possibly further afield, so if folks can take the opportunity to check the dirt zone of our major roads it will be interesting to find out how widespread the taxon really is - hopefully further clarification of its identification will come in good time.

Image above showing a couple of shoots mixed in with D. tophaeceus, B. convoluta and P. hornschuchianum.

Stumped on the hard shoulder

Apologies for bringing this post to the top, but it's an intriguing taxon worth bringing attention to (additional text shown yellow). Using the key to North American Didymodon I was taken on a pretty unambiguous journey to australasiae, a taxon which appears to be recognised in other parts of Europe as well as North America. The last part of the key identifies the key characters separating this species from umbrosus, which even with my limited experience, really looks very different and distinctions are clear. Interestingly David Holyoak's comments on Cornish material indicates that both australasiae and umbrosus occur there, both even confirmed by DNA. Given all this information I'm confused as to why australasiae is not included on the British list.

For the record the following additional images show the extra characters referred to in the key i.e. the bistratose margin towards the leaf tip (NB the proximal 2/3 of the margin is unistratose), strongly papillose cells, quadrate adaxial cells (presenta long the full length of the costa).

As can be seen below, the habitat was very mundane, the species occurring as patches in the outermost zone of colonised dirt (arrowed white, although I think my specimen came from the area indicated by the yellow arrow SN53100107). Direct associates in my sample include Didymodon tophaceus, Barbula unguiculata and Bryum dichotomum. PS. Thanks for the earlier comments, which prompted further examination of my sample.

Maybe it's just because I've had a long day but this one has me stumped. It was growing in the gritty debris of a roadside near Dafen, Llanelli, the most frequent associates including Cochlearia danica, Barbula unguiculata, Plantago coronopus, etc. Help please!