Biology and spread of the new alien species Coreopsis grandiflora (Asteraceae) in southern Switzerland
29-11-2022 Info
Coreopsis grandiflora - a new alien species in Ticino
Coreopsis grandiflora is an ornamental species native to Northern America. The species first attracted attention in Switzerland in 2019 when it was observed in vulnerable riverine habitats near Locarno. Initially, however, it was identified as Coreopsis lanceolata, which was already known in Switzerland. Nowadays, the species is widespread on thermophilic sites around Locarno, not only in floodplains but also along railway lines and roads, in meadows, vineyards and ruderal areas.
The new publication (in English with Italian summary) by Brigitte Marazzi, Sofia Mangili, Andreas Gygax and Antoine Jousson presents an identification key to distinguish the two Coreopsis species, documents the biology, taxonomy and distribution and investigates the invasive potential.
Due to the observation of dense stands coupled with high number of seeds, the authors conclude that Coreopsis grandiflora has a potentially invasive behavior, despite its limited vegetative reproduction and natural dispersal primarily over short distances. Furthermore, humans contribute to the spread of the garden species. Further research, especially in floodplain areas, and active control are recommended.
