T. PhutthaiM. HughesFaculty of Environment and Resource Studies, Mahidol UniversityRoyal Botanic Garden Edinburgh2018-12-212019-03-142018-12-212019-03-142017-07-01Edinburgh Journal of Botany. Vol.74, No.2 (2017), 149-16114740036096042862-s2.0-85015092453https://repository.li.mahidol.ac.th/handle/20.500.14594/41469© Trustees of the Royal Botanic Garden Edinburgh (2017). Four new species of Begonia are described from Northern, Peninsular and Southwestern Thailand. Three belong to Begonia sect. Diploclinium (B. exposita Phutthai & M.Hughes, B. pengchingii Phutthai & M.Hughes and B. pseudosubperfoliata Phutthai & M.Hughes), and one (B. phutthaii M.Hughes) to Begonia sect. Apterobegonia. All four species are karst limestone endemics. The provisional IUCN status of all the new species is 'Vulnerable'.Mahidol UniversityAgricultural and Biological SciencesArticleSCOPUS10.1017/S0960428617000051