Wen Hong ChenSirilak RadbouchoomHieu Quang NguyenThamarat PhutthaiLeonid V. AveryanovYu Min ShuiFaculty of Environment and Resource Studies, Mahidol UniversityUniversity of Chinese Academy of SciencesRussian Academy of SciencesChinese Academy of SciencesKunming Institute of Botany Chinese Academy of SciencesVietnam Union of Science and Technology Associations2019-08-232019-08-232018-12-07Phytotaxa. Vol.381, No.1 (2018), 132-14011793163117931552-s2.0-85058472421https://repository.li.mahidol.ac.th/handle/123456789/44619© 2018 Magnolia Press. Due to the unavailability of specimens and publications in the past, some gaps exist in knowledge of similar species from various adjacent countries. After more recently detailed observations from field surveys and examinations on herbaria specimens, we confirmed the status of Begonia arboreta and B. sonlaensis as synonyms of B. garrettii and B. pseudodryadis from China and Thailand, and from China and Vietnam, respectively. The taxonomic treatment is based on the examination of both available herbarium specimens and living plants from different populations. Taxonomy revision of the allied species is very important for understanding plant diversity in the above neighboring countries.Mahidol UniversityAgricultural and Biological SciencesArticleSCOPUS10.11646/phytotaxa.381.1.17