A frosty day at Llantrisant Common

On 28th December I spent a sunny day recording bryophytes on Llantrisant Common with Karen Wilkinson and Caroline O'Rourke.

Although the weather was beautiful the ground frost never cleared - Karen was reduced to ripping up chunks of frozen Sphagnum to take home to identify. We probably missed some smaller species as a result - there was no chance of picking through Sphagnum in the field to look for small liverworts, for example.

We covered the western bits of the common and succeeded in upping tetrad ST08M from 46 to 75 taxa. The existing site list was largely made up of records from CCW vegetation surveys in the 90s, topped up with a few grots I recorded in 2015. There were no epiphytes on the list however, and these made up the bulk of the additions. We'd hoped to re-find Scapania paludicola, recorded in several places by CCW, and got excited by some promising Scapania in M15 wet heath, but this proved on closer inspection to be S. irrigua.

The highlight of the day was a small patch of Atrichum crispum close to a stream (5th Glamorgan tetrad, top photos below). Other finds included Calliergonella lindbergii (below left) among short grass in several places, Pseudephemerum nitidum and vegetative Physcomitrium pyriforme (hopefully safe to record) rubbing shoulders in a rushy ditch (below right) and Orthotrichum stramineum on an old willow.

 

Karen recorded 6 species of Sphagnum including S. fimbriatum and S. fallax new for the site, as well as some beautiful wine-red S. capillifolium.

We strayed into the southern part of the common, which falls within ST08L, and took the total for that tetrad from 53 to 63 taxa. We didn't have time to explore the extensive eastern side of the common and are planning a return visit sometime...

Upper reaches of the Afon Tywi

The rocky upper reaches of Afon Tywi, north of Lynn Brianne, couldn't be more different from the lowland, meandering section of the river with which I'm familiar from winter Brown Hairstreak egg surveys.

 

A couple of weekends ago we stayed a night at Dolgoch Hostel in Ceredigion, just a field away from the Tywi (which here forms the boundary between VC46 and VC42). Sam had provided me with a list of rare bryos to look out for, and though I failed to find any of these there was still plenty of interest - for me at least. Most notable, perhaps, was the abundance of Atrichum crispum, here growing on the thin soil layer on top of large river boulders.

I was also impressed by the quantity of Andraea rothii ssp falcata on the in-channel rocks, sometimes growing not far above the water level. A small patch of the lichen Lasallia pustulata (please correct my ID if wrong!) was growing in the same habitat.

The river itself was full of great wefts of Fontinalis squamosa, and Oligotrichum hercynicum was frequent on steep gravelly banks.

I'm a little puzzled by this falcate Campylopus, which had the nerve filling about a third of the leaf base. It might just be C. flexuosus, but is almost lacking in tomentum and doesn't have any obvious coloured cells in the basal angles of the leaf.

Sam tells me this part of the Tywi has been little studied bryologically. It surely warrants a proper look.

Upper Clydach Valley (cont)

In addition to yesterdays fruiting Tetraphis (below left), there were also abundant Nowellia sporophytes, plus some Lepidozia capsules (below right). I brought some of the latter home to check for pearsonii as some patches looked rather leggy and more sprawling than reptans. However, sporophytes are unknown in pearsonii and the habitat was also wrong - too much wishful thinking on my part! Looking at the distribution of pearsonii it looks a reasonably feasible possibility, so worth bearing in mind, especially in humid rocky sites.

Atrichum crispum

Source of the Llan

... well actually, 400m downstream from it, where I managed to squeeze in a quick smash and grab session in failing light (15:45-16:15). Although the water course and its banks seemed to support a rather limited bryo-flora, there were a couple of species of interest: Warnstorfia fluitans (locally frequent on the grassy flood zone alongside the stream) and Atrichum crispum, the latter conveniently growing adjacent to A. undulatum. Like the Warnstorfia it was mostly under water following the recent rains, hence no field shots. The species has a very different look to undulatum, with the shoots being more lax and a much brighter green. The photo below shows the narrowed leaf base and broad leaf shape. The ridges on the costa are smaller than those of undulatum, which you can get an impression of through a lens (just visible in photo above - you may need to zoom in a bit), which rules out any confusion with Mnium. This was only the third Glamorgan tetrad record, but given the rather mundane habitat, it's one we might expect to see more of in upland streams.

Warnstorfia fluitans with what looks like rather large alar cells, but the habitat, habit (dense sprawling mat) and presence of rhizoids on the leaf tips (with algae entangled) all make a safe id. Note the denticulate margins rule out Drepanocladus.