The taxonomic status, synonymy and nomenclature of Buglossoides rochelii comb. nov. (Boraginaceae), a neglected plant of south-eastern Europe

The identity of Lithospermum rochelii, so far known only from its type locality (Bulgaria, hills in Plovdiv town), remained hitherto uncertain. Our examination of its original material and re-collection of the species from its locus classicus in Plovdiv town revealed its identity with Lithospermum glandulosum (syn. Buglossoides glandulosa) described later from an adjacent area, in the towns of Sadovo and Asenovgrad (Plovdiv Region), and Lithospermum czernjajevii (syn. Buglossoides czernjajevii), described from north-eastern Ukraine in the 20th century. The diagnostic characters of L. rochelii and related taxa are clarified, and the distribution area of this species is verified and mapped. A lectotype is designated for L. rochelii and a new combination is provided, Buglossoides rochelii. The chromosome number 2n = 2x = 16, the first ever record for the species, confirms its sharp separation from all other members of Buglossoides s.str., for which only the base chromosome number x = 7 has been known.Peer reviewe