New nomenclatural combinations in Cleome sensu stricto (Cleomaceae) from Eastern Europe and the Caucasus

The genus Cleome sensu stricto comprises ca. 22 species naturally distributed across several regions of western Eurasia and Africa, but taxonomic uncertainty persists, particularly in Eastern Europe and the Caucasus. This study addresses conflicting taxonomic viewpoints regarding several Cleome taxa, namely C. canescens, C. donetzica, C. circassica, and C. daghestanica, which some authors consider distinct species, while others synonymize them under C. iberica or C. ornithopodioides. Based on morphological distinctions and geographic isolation, the recognition of these taxa as subspecies within C. iberica is proposed. The necessary nomenclatural combinations are provided. This study contributes to standardizing the taxonomy of Cleome s. str., offering nomenclatural options for future floristic research and plant conservation efforts.