Rubus occidentalis (Rosaceae) - a new naturalized raspberry species in the Polish flora

Rubus occidentalis L., native to eastern North America, is recorded for the first time as naturalized in Poland. Its spontaneous occurrence in Europe has hitherto been mentioned only from several stands in the Czech Republic and from single localities in Slovakia and Russia. The increasing popularity of black raspberry cultivation and its ability to survive under different environmental conditions suggest that the number of instances of its appearances in semi-natural habitats will grow over time. At the moment, R.occidentalis can be considered as a locally established, non-invasive neophyte.