Solanum torvum Sw. (Solanaceae): a new alien species for Europe

The largest family of Solanaceae counts many species widespread worldwide, either wild and cultivated. A lot of cultivated species of this family represent an important part of the world of food. These and other spontaneous plants have several ethnobotanical uses. In this paper, the author reports for the first time about the presence, as casual alien species, of Solanum torvum Sw. in Europe (Calabria region, Southern Italy). Actually, it was reported in Italy by mistake until then. This species is native of West Indies and naturalized in several tropical and subtropical regions worldwide. S. torvum, also used as rootstock for cultivated Solanaceae, can escape and invade natural habitats, replacing the natural vegetation and creating changes in relationships with other species. Twenty-three plants of S. torvum are located in a stream, living together with other alien and synanthropic species. This work deals with its geographical distribution and new location, with its morphological, ecological and taxonomic characteristics. S. torvum, can be considered in Italy and in Europe as an alien casual species, but further field investigations on this species are necessary to avoid its diffusion.