© 2017 The AuthorsBolanthus sandrasicus Hamzaoğlu & Koç sp. nov. from the Muğla province, SW Turkey, is described. This new species resembles B. thymoides Hub.-Mor., but differs in both macromorphology and seed micromorphology. Furthermore, we investigated the phylogenetic relationships of all Bolanthus species distributed in Turkey using ITS and trnL–trnF sequence data. The results of both morphological and molecular analyses support the description of the recently discovered Muğla population as a distinct species. In addition, a diagnostic key to all Bolanthus species growing in Turkey is provided.