An infrageneric classification of the genus Lejeunea (Marchantiophyta: Lejeuneaceae) using molecular phylogeny and morphology

Background and aims – The genus Lejeunea , with about 375 accepted species, is one of the most species-rich and intricate genera of liverworts. Here, we present the first integrative, worldwide infrageneric classification of Lejeunea based on morphology and molecular-phylogenetic analyses. Material and methods – Maximum likelihood analysis and Bayesian inference of sequences from two chloroplast regions ( trn L- trn F, rbc L) and the nuclear ITS region of about 35% of the species, combined with morphological evidence. Key results and conclusions – The phylogenetic analyses revealed numerous robust clades within two major lineages, corresponding to subgenera Lejeunea and Crossotolejeunea . Integrating molecular phylogenetic evidence and morphological data, we describe 15 sections: four in subg. Lejeunea (sect. Glaucescentes , sect. Lamacerinae , sect. Lejeunea , sect. Macrolejeunea ) and 11 in subg. Crossotolejeunea (sect. Apolejeunea , sect. Crossotolejeunea , sect. Echinocolea , sect. Flavae , sect. Heterolejeunea , sect. Inflatolejeunea , sect. Minutilobae , sect. Nanolejeunea , sect. Papillolejeunea , sect. Sordidae , sect. Xenantholejeunea ). Four sections have a neotropical distribution, three are pantropical, two are pantropical and extend into temperate regions, two are Afro-American, two are Asian, one is Asian-Australasian, and one has a tropical amphi-Pacific range.