First report of Baccharis spicata in Portugal
Baccharis (Asteraceae) is a large plant genus containing up to 500 species native to the Americas. Three Baccharis species are grown in European gardens - B. magellanica, B. patagonica and B. halimiflora, where the latter is an invasive species and recommended for regulation by EPPO (A2 species) as well as being included on the EU list of Union Concern. Baccharis spicata is native to South America (Brazil, Paraguay, Uruguay and Argentina) and is reported for the first time in Portugal (and Europe). Two naturalized populations were recorded in September 2015 around the city Porto (Vila do Conde and Matosinhos). The population at Vila do Conde includes numerous individuals (over 100) with some several years old and reaching a height of more than two metres. At Matosinhos, 15 individual plants were recorded attaining a height of between 0.5- 2 m. At both sites, B. spicata grows on disturbed ground where other highly invasive species such as Acacia longifolia, A. melanoxylon, Cortaderia selloana and Paspalum dilatatum are found. The authors evaluated the risk of B. spicata to the European Union through risk assessment and concluded that the species poses a significant risk to the region. The two populations are currently under management.
Verloove F, Dana ED, Alves P (2017) Baccharis spicata (Asteraceae), a new potentially invasive species to Europe. Plant Biosystems http://dx.doi.org/10.1080/11263504.2017.1303001