Notes to the non-native flora of Campania (Southern Italy)

This contribution adds new information on the non-native flora of Campania, with special attention to doubtfully present taxa. After new observations in the field and on herbarium material, joined with a deeper insight into literature, 13 taxa are to be excluded from the regional flora (Viola williamsii must to be excluded from the flora of Italy), while one was probably present in the past. In addition, the occurrence, even in the past, of further 3 taxa is to be regarded as very doubtful. However, our researches allow to identify localities for a naturalized species previously reported only generically for the region, i.e. Chasmanthe bicolor (Iridaceae). In addition, Senecio squalidus subsp. chrysanthemifolius (Asteraceae), naturalized, must be added to the regional flora. We propose also the naturalized status for Kalanchoë ×houghtonii (Crassulaceae). Drosanthemum hispidum (Aizoaceae) is confirmed as a casual alien. Moreover, further 14 new casual aliens are added to the regional flora, among which Acalypha supera (Euphorbiaceae), Begonia Semperflorens Cultorum Group (Begoniaceae), Canna ×generalis (Cannaceae), Jasminum polyanthum (Oleaceae), Lantana Callowiana Hybrid Group (Verbenaceae), and Sedum rubrotinctum (Crassulaceae) are new to Italy. Most of the new additions is represented by plants escaped from gardens. Therefore, the cultivation of ornamental plants once again results a relevant pathway of introduction. Finally, some explanatory notes to a few data occurring in the last regional checklist are provided