New Alien Plant Species Recorded in South Lithuania

Abstract Performing a thorough inventory of alien plant species in the southern part of Lithuania, we found twelve alien plant species previously not registered in the country: Aruncus dioicus, Buxus sempervirens, Clematis vitalba, Clematis recta, Colutea arborescens, Erechtites hieraciifolius, Erigeron strigosus, Euphorbia marginata, Genista sagittalis, Lathyrus latifolius, Sempervivum arachnoideum and Silphium perfoliatum. All newly recorded alien species, except Erechtites hieraciifolius and possibly Genista sagittalis, have been introduced intentionally and escaped from cultivation. Ten species currently occur as casuals, whereas Colutea arborescens and Genista sagittalis are locally naturalised. Naturalisation of Buxus sempervirens and Euphorbia marginata in the foreseen future is unlikely in Lithuania, naturalisation of Aruncus dioicus, Sempervivum arachnoideum and Silphium perfoliatum is possible. In contrast, naturalisation of the other five species is expected in the nearest future. Invasion of seven analysed alien species is unlikely in Lithuania, whereas Clematis vitalba, Colutea arborescens, Erechtites hieraciifolius, Erigeron strigosus, Lathyrus latifolius have the potential to become invasive in the country. Therefore, their reproduction and spread should be monitored, and measures for prevention of their invasion should be applied, if necessary.