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.