Phylogenetic system and classification of the family Scapaniaceae Mig. emend. Potemkin (Hepaticae)

The phylogenetic system and classification of the family Scapaniaceae Mig. emend. Potemkin as a whole are presented for the first time. The classification of the family is significantly revised. Scapaniaceae is classified with 87 recent and one fossil species in 18 sections and three subgenera of one genus, Scapania (Dumort.) Dumort. emend. Potemkin. Subgenus Scapania has 82 species in 18 sections, subgenus Macrodiplophyllum (H. Buch) Potemkin has three species, and subgenus Macroscapania R.M. Schust. has two species. Earlier distinguished subgenera Plicaticalyx Müll. Frib. and Ascapania Grolle are merged in the sectio Plicaticalyx (Müll. Frib.) Potemkin, comb. & stat. nov., of the subgenus Scapania. The taxonomic composition of many sections is considerably revised, and the species composition of all infrageneric groups is listed in a systematic arrangement. Alteration of the species composition and/or species differentiation (including keys) of the sections Ciliatae Grolle, Gracilidae H. Buch, Nemorosae (Müll. Frib.) H. Buch, Planifoliae (Müll. Frib.) Potemkin, Plicaticalyx, Scapania, and Verrucosae Potemkin of the subgenus Scapania as well as of the subgenera Macrodiplophyllum and Macroscapania are provided. New sections are described for Scapania karl-muelleri Grolle (Grolleoscapania Potemkin, sect. nova) and for S. schljakovii Potemkin and S. himalayica Müll. Frib. (Muelleria Potemkin, sect. nova). A number of new synonyms and index for identification of taxonomic position of mentioned taxa of Scapania are provided.