A newcomer from the east: naturalisation of Gypsophila perfoliata L. around the city of Miskolc (north-east Hungary).
Gypsophila perfoliata (Caryophyllaceae) is a rare, only casually occurring species in Central Europe. Its native range spans from western Asian to the coast of the Black Sea. Several adventive occurrences of G. perfoliata were documented in Central Europe, especially in Germany where the naturalisation of the taxon occurred during the first decades of the 20th century. As a rare weed, it is suspected to have been introduced with iron ore from the former Soviet Union via railways (Kryvyi Rih region, now Ukraine). In this paper, we gathered information on the occurrence of G. perfoliata from its adventive range. These data indicate an ongoing and fast spread of the species across Central and Eastern Europe. For instance, prior to this study, G. perfoliata have two occurrence records from Hungary. Six new and recent records from Miskolc town and its surrounding areas are presented in this paper. The studied plant occurs in former industrial areas (steel factory, transshipment yards, external slag heaps) or along transport lines (esp. road verges, railway lines). We also describe 18 phytosociological relevés taken at the location of occurrences. All occurrences were documented on heavily modified anthroposols, where the populations flourish on bare ground (esp. road verges or parking areas) or on ground with admixture of metalliferous slag debris. With the help of available orthophotos the presumed land-use history of the locations has also been reconstructed. Based on data presented here we recommend modifying the species' adventive status in Hungary from casual to naturalised. Further expansion of the species is expected not only at industrial sites but also at locations where slag material was utilised (e.g. landfill, road and rail construction). Due to its halophyte characteristics the species might expand its range along roads where de-icing salt is used.