Geographical origin of L eucobryum boninense Sull. & Lesq. ( L eucobryaceae, M usci) endemic to the B onin I slands, J apan

L eucobryum boninense is endemic to the B onin I slands, J apan, and its related species are widely distributed in A sia and the P acific. We aimed to clarify the phylogenetic relationships among L eucobryum species and infer the origin of L . boninense . We also describe the utility of the chloroplast trnK intron including matK for resolving the phylogenetic relationships among L eucobryum species, as phylogenetic analyses using trnK intron and/or matK have not been performed well in bryophytes to date. Fifty samples containing 15 species of L eucobryum from A sia and the P acific were examined for six chloroplast DNA regions including rbcL , rps4 , partial 5′ trnK intron, matK , partial 3′ trnK intron, and trnL ‐ F intergenic spacer plus one nuclear DNA region including ITS . A molecular phylogenetic tree showed that L . boninense made a clade with L . scabrum from J apan, T aiwan and, H ong K ong; L . javense which is widely distributed in East and Southeast A sia, and L . pachyphyllum and L . seemannii restricted to the Hawaii Islands, as well as with L . scaberulum from the R yukyus, J apan, T aiwan, and southeastern C hina. L eucobryum boninense from various islands of the B onin I slands made a monophylic group that was closely related to L . scabrum and L . javense from Japan. Therefore, L .  boninense may have evolved from L . scabrum from J apan, T aiwan, or H ong K ong, or L . javense from J apan. We also described the utility of trnK intron including matK . A percentage of the parsimony‐informative characters in trnK intron sequence data (5.8%) was significantly higher than that from other chloroplast regions, rbcL (2.4%) and rps4 (3.2%) sequence data. Nucleotide sequence data of the trnK intron including matK are more informative than other chloroplast DNA regions for identifying the phylogenetic relationships among L eucobryum species.