Genetic analyses reveal the taxonomic identity and glacial relict history of Betula costata trees in Japan

Article excerpt

In recent years, several populations of the deciduous tree Betula costata have been identified in central Japan. Since this species is morphologically similar to closely related taxa, particularly Betula ermanii, its presence remained unrecognized for a long time. Accordingly, B. costata is now regarded as a relict species that provides important insights into the historical development of cool-temperate forests in the Japanese archipelago.