The Danube is not a border for geophytes: Ornithogalum refractum (Asparagaceae) discovered in Slovakia

Abstract Current number of species of Ornithogalum s. lat. in Slovakia is eight. We here report the discovery of a ninth species, Ornithogalum refractum Kit. ex. Willd. The species was first discovered in the vicinity of Štúrovo town in southern Slovakia in April 2023. We used a multi-method biosystematic approach to demonstrate its difference from morphologically similar species O. divergens Boreau. Flow cytometry and chromosome counting revealed that pentaploids and hexaploids of O. refractum occur in Slovakia. Its residence time in Slovakia is unclear, but we suggest that it is not of a recent origin, and the species occurrence has been overlooked due to its superficial similarity with O. divergens . The species occurrence in southern Slovakia represents a continuation of its distribution in northern Hungary and it is probably the northernmost in the entire range.