During my visit to Clwyd last week I collected an interesting-looking Orthotrichum from a Sycamore on the calcareous lead mine we were surveying. Its orange-tipped, hairless calyptrae looked good for O. pallens, although I have recently been fooled by forms of O. stramineum so I wasn't too hopeful. To my relief, a microscope check revealed nicely exposed cryptopore stomata, and removing a ripe capsule's lid released a peristome with 16 endostome teeth (8 in virtually all confusion species). Hooray!
This is the second Welsh record following on from a few tufts on a Field Maple in a hedge at Dingestow, but given the rapid increase in this moss in England I'm sure it won't be the last Welsh record.