I could only manage a very short lunch-break last Thursday so I spent 10 minutes grotting around for bryophytes on the edge of the A466 south of Wyesham. The road was surprisingly quiet so I was able to grab a good number of patches of moss to look at. Bryum dichotomum dominated, but there were 17 other species including T. modica. A full DAFOR was:
A Bryum dichotomum
F Barbula unguiculata, Funaria hygrometrica, Phascum cuspidatum, Tortula truncata
O Bryum rubens, Ceratodon purpureus, Didymodon insulanus, Kindbergia praelonga, Syntrichia ruralis, Tortula modica
R Barbula convoluta, Brachythecium rutabulum, Bryum argenteum, Cratoneuron filicinum, Didymodon umbrosus, Pseudocrossidium hornschuchianum, Rhytidiadelphus squarrosus.
The alert bryologist reading that list of mundanities will have spotted one unusual name - Didymodon umbrosus. There were two small patches of this tiny squarrose-leaved moss on sandy loam just above the concrete lip of the verge. Microscopic confirmation revealed hyaline leaf bases with elongate marginal cells. This is a very different habitat to the previous times I have seen D. umbrosus, when it has been growing rather low down on damp, shaded walls. The A466 habitat is admittedly overhung by grass and gets regularly splashed, but it is pretty exposed. The Atlas reveals that there are English records from tracks, carparks and even a bulb field on Scilly, so perhaps this record is only really odd in a Welsh context. There appear to be just 3 previous Welsh records: two from Glamorgan and one from Monmouthshire, but this record suggests it could be very widely overlooked.