Undulating Mosses

Steve Gale, over at North Downs and Beyond, has recently commented on the excellent new Mosses and Liverworts of Britain and Ireland: a Field Guide, published by the British Bryological Society. My copy arrived today and it is excellent, if  a little intimidating - the number of species seems to have increased since the last time I looked closely at these intriguing little plants. Above is Atrichum undulatum, known as Catherine's moss, which has distinctly undulating leaves (double-click for a better image) and capsules that are like miniature pepperpots when you pull the lid off - illustrated here. I once read that it was named after Catherine the Great of Russia (and was originally named Catharinea undulata) but I've never found out whether this is true or what she might have had in common with a lowly woodland moss. I think the lower photo shows Plagiomnium undulatum, also with undulating leaves, decorated with a light rime of frost. Now I've bought the book, I'll have to get my money's-worth and try to identify the other 761 British moss species...