Euphorbia prostrata (Euphorbiaceae), a new alien in the Carpathian Basin.
During the study of the urban flora of the city of Szeged (southern Hungary) in 2011, about 100 specimens of Euphorbia prostrata Aiton, a new alien for the Hungarian flora, were found in a city park. Characterisation of the locality is provided. This record, being the one and only in the Carpathian Basin so far, confirms former observations that this meridional-subtropical species is in expansion in many parts of the world, including proper habitats of the temperate regions. A key for all species of the genus Euphorbia subgenus Chamaesyce for the region is given.