A phylogeny of the northern temperate leafy liverwort genus Scapania (Scapaniaceae, Jungermanniales)

Scapania is a northern temperate genus with a few disjunctions in the south. Despite receiving considerable attention, the supraspecific classification of this genus remains unsatisfactorily solved. We use three molecular markers (nrITS, cpDNA trnL-F region, atpB-rbcL spacer) and 175 accessions belonging to 50 species (plus eight outgroup taxa) to estimate the phylogeny and to test current classification systems. Our data support the classification of Scapania into six rather than three subgenera, rearrangements within numerous sections, and inclusion of Macrodiplophyllum microdontum. Scapania species with a plicate perianth form three early diverging lineages; the most speciose subgenus, Scapania s.str., represents a derived clade. Most morphological species concepts are supported by the molecular topologies but classification of sect. Curtae requires further study. Southern lineages are nested in northern hemispheric clades. Palearctic-Nearctic distribution ranges are supported for several species.

GraphicalabstractDownload full-size imageHighlights► We report the first global phylogeny of Scapania based on 184 accessions and three molecular markers. ► Molecular phylogenies are not congruent with current supraspecific classifications. ► We propose a classification into six subgenera and rearrangements within numerous sections. ► Scapania irrigua is paraphyletic with several species nested in it. ► Southern lineages are nested in northern hemispheric clades.