Intergrative Taxonomic Study of the Frullania parvistipula Complex with a Modern Circumscription of the Section Trachycolea (Frullaniaceae, Marchantiphyta).

Frullania (subg. Trachycolea ) sect. Trachycolea has been studied using integrative taxonomy methods and utilizing sampling from almost all areas of distribution of the species previously referred to this section. A phylogenetic analysis based on nuclear ribosomal ITS1-2 and chloroplast trn L-F sequence data and a morphological study reveal a wide range of morphological variability within specimens that has largely disguised the overall taxonomic diversity. Frullania parvistipula , previously regarded as a widespread species, has been found to represent a group of separate species within different sections of F. subg. Trachycolea : F. caucasica and F. conistipula in F. sect. Trachycolea , F. parvistipula in F. sect. Australes , and F. fukuzawana in F . sect. Integristipulae II. Illustrations of the type specimens of F. conistipula , F. fukuzawana , and F. parvistipula , as well as illustrations of the sequenced specimens belonging to two of the discussed species ( F. conistipula and F. parvistipula ), are provided. The morphological differences separating the highly similar F. caucasica , F. conistipula , F. fukuzawana , F. koponenii , and F. parvistipula are discussed. A dichotomous key is presented for accepted species. New combinations are provided for two taxa.