Analytical key for the identification of the Frullania species in Europe and Macaronesia. - After some methodological remarks about the observation of theFrullania(Marchantiophytina, Bryophyta), akey for the identification of the 14 species of the genus in Europe and Macaronesia is provided. For each species, critical taxonomical and/or chorological notes, and a key for infraspecific taxa are given. Two important taxonomical and nomenclatural notes are made aboutF. aeolotisand about theF. cesatiana / F. muscicola / F. ripariacomplex. The taxa recognized in Europe and Macaronesia are listed with most of their synonyms.