Abstract
Grimmia subsquarrosa Wils. and G. stirtonii Schimp. are reduced to synonymy with G. trichophylla Grev. G. trichophylla var. tenuis (Wahlenb.) Wijk&Marg. isrestored to specific status (as G. muehlenbeckii Schimp.) and deleted from the list of British species. Var. robusta (Ferg.) A. J. E. Smith is restored to specific status as G. britannica A. J. E. Smith nom. nov. and shown to be endemic to the British Isles.