In Japan 625 species in 146 genera of liverworts and 17 species in 6 genera of hornworts are recognized. Many nomenclatural changes, a number of new species and infraspecific taxa (subspecies or varieties) of liverworts and hornworts have been reported for the Japanese flora since the previous checklist of Furuki & Mizutani (2004) which recognized 614 species in 134 genera of liverworts and 17 species in 6 genera of hornworts. Current names of Japanese liverworts and hornworts are alphabetically listed with annotations. In the annotations, the taxonomy, nomenclature and synonymy of many of the accepted species and infraspecific taxa (subspecies or varieties) are discussed briefly, based primarily on recent literature sources published up to 31st December 2010 and the authors' observation. One new combination: Sphenolobus ellipticus (Inoue) T.Katag. & Furuki and one new name: Chiloscyphus yezoensis T.Katag. & Furuki are proposed. Cololejeunea pakseana Tixier is newly synonymized with C. uchimae Amakawa. Names of uncertain application and those reported in error from Japan are appended. Homotypic (nomenclatural) synonyms are indicated in the annotations by the symbol = and heterotypic (taxonomic) synonyms by the symbol =.
Three-celled gemmae produced in leaf axils of Pterigynandrum fliforme are newly reported from a single population in Kyoto Prefecture, central Japan. The gemmae are abundantly produced in leaf axils of ascending secondary stems. Caducous branchlets are also found in the same population; both types of asexual reproductive organs are even produced in the same leaf axils.