Leycesteria formosa, an invasive alien plant in the Azores (PT)
Leycesteria formosa (Caprifoliaceae) is a shrub reaching 2 to 3 m high with large ovate leaves up to 24 cm long and 9 cm wide. It originates from Asia (India and temperate Himalayas) and was introduced in Australia, New Zealand and California (US) as an ornamental plant. In the EPPO region, it is recorded in Great Britain, Ireland and France (including Corse) and is considered among the 100 most invasive alien plants in Macaronesia due to extensive populations in São Miguel Island (Azores, Portugal). In the Azores, the species has also recently been found in Terceira Island. The species reproduces sexually and produces a large number of berries which are dispersed by birds and water runoff associated with heavy rains. The species can also resprout from stems or pieces of stem, which can be spread through garden waste.
In the Azores, L. formosa is recorded in habitats such as: Calluna shrublands; Laurus, Ilex, and Juniperus forests; pasture margins; water stream banks; roadsides; Cryptomeria planted forest and woodlands with the introduced Pittosporum. In addition, it occurs in protected areas (i.e. Pico da Vara/Tronqueira special protection area and Lagoa do Fogo nature reserve).
As only 3 individual plants were found in Terceira Island, surveillance is recommended. Monitoring would also be of value in EPPO countries where the species occurs, to gather information on its behavior.
Sources
Australia Virtual herbarium, Leycesteria formosa. http://avh.ala.org.au/occurrences/search?taxa=leycesteria+formosa
DAISIE Database, Leycesteria formosa. http://www.europe-aliens.org/speciesFactsheet.do?speciesId=24120
Silva L, Marcelino J, Resendes R, Moniz J (2009) First record of the top invasive plant Leycesteria formosa (Caprifoliaceae) in Terceira island, Azores. Arquipélago. Life and Marine Sciences 26, 69-71.
Tela Botanica, Leycesteria formosa.http://www.tela-botanica.org/bdtfx-nn-38837-synthese