Two alien species of Bidens (Asteraceae) new to the flora of Serbia
Two new alien species Bidens connata (Bidens conatus) and Bidens subalternans (Asteraceae) have been recorded in the flora of Serbia. B. connata is native to North America and is widespread throughout Europe. In Serbia B. connata was found near the town of Niš along the rivers Gabrovačka and Nišava. In these areas the population is stable with several thousand individuals forming linear populations. The species was first recorded in Europe in 1965 and is now present in 14 countries. B. subalternans is native to South America and the first record of the species in Europe is from Belgium in 1903. The population of B. subalternans in Serbia was recorded from the town of Niš in the central railway station in ruderal habitats around the abandoned tracks and platforms. The population, which covers an area of several hundred square metres, is thought to have been established for several years now even though management measures (manual and chemical control) have been applied to the site every year to facilitate the functionality of the railway infrastructure. In many countries, B. subalternans is an agricultural weed which invades a variety of habitats including stream and river banks, ruderal habitats, coastline, roadsides, vineyards, olive groves and gardens and parks.
Sources
Bogosavljević SS & Zlatković BK (2015) Two alien species of Bidens (Compositae), new to the flora of Serbia. Phytologia Balcanica 21, 129-138.