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

Pointed Beard-moss at Merthyr Mawr

Compared to the scrappy little colonies of Didymodon acutus along the Gower coast, those at Merthyr Mawr are much larger and hence much easier to spot. The species was first noted here by Sam in 2012 and it was just good fortune, rather than forward planning, that I happened to walk over exactly the same area last week and recorded exactly the same strong colony. The habitat comprised patches of very short, rabbit-grazed dune grassland between swathes of Rosa spinosissima (photo below). Associates included Bryoerythrophyllum recurvirostrum, Barbula convoluta var. convoluta, Hypnum cupressiforme var. lacunosum, Ditrichum gracile, Ceratodon purpureus and Pseudocrossidium hornschuchianum.

As hard as I try, autumn fungi are often too attractive to ignore, as was the case with what looks like Clavaria vermicularis fruiting in a rabbit excavation. I couldn't decide what the Hygrocybe was, which will be left unidentified unless someone can name it for me (neither the stipe or the cap seemed particularly viscous).