While going through some of the NPT forest road records in MapMate I noticed that there was a record of Campylopus fragilis for Nant y Cafn attributed to H and me. After checking my vouchers I found a packet labelled 'Campylopus fragilis or Campylopus subulatus in calcareous grassy verge near forest track, Nany Cafn (23/4/17)'. Clearly I hadn't nailed this. So we went up to the site yesterday to collect some fresh specimens. The photo below (taken last April) shows the plants in situ. There is a very large population in the vicinity of SN81610756 which is very conspicuous and although on close inspection it is obviously a Campylopus, the colony has a bright yellowish-green colour which looks a bit like Ditrichum gracile from distance.
The plants are rather short-leaved and there is no tomentum. Deciduous shoot tips are abundant all over the colony.
The leaves have no auricles to speak of, there is a wide costa (at least 70% of leaf width at base) and the thin-walled basal cells are linear/rectangular. The alar cells are larger but not differentiated greatly fro the basal cells and not thick-walled and pigmented like those of Campylopus flexuosus.
A section of the costa shows the large adaxial cells which occupy about 35- 40% of costa thickness and the absence of stereid cells. The leaf tip has a few distinctive teeth.
I'll amend the record in Map Mate.