Orthotrichum patensBruch & Brid. (Bryophyta, Orthotrichaceae) in Suffolk and Derbyshire, another epiphytic moss new to Britain

Orthotrichum patens is reported new to Britain from two sites in the counties of Suffolk and Derbyshire. Previous reports of this species in Britain are thought to be based on O. affine; they date from the nineteenth century at a time when the structure of the stomata was not recognised as significant. Orthotrichum patens is described and illustrated, and its diagnostic characters are discussed. Some comments are included on changes in the epiphytic bryophyte flora in Britain in recent decades.