Acknowledgements
Thanks are due to the herbarium curators at BM and E for access to specimens. The distribution map was produced using the DMAP program of Alan Morton. I am grateful for helpful comments from two anonymous reviewers.
Note on contributor
Tim Blackstock worked for the Nature Conservancy Council and subsequently the Countryside Council for Wales in Bangor. The main focus of his role was habitat ecology and conservation, with a specialist interest in bryology. Since retirement, he has undertaken field bryological projects, mostly on liverwort reproductive biology.