First report of the casual occurrence of Handroanthus heptaphyllus in Sicily (IT)
Handroanthus heptaphyllus (Bignoniaceae) is a tree species native to sub-tropical and tropical South America (Brazil, Argentina, Bolivia and Paraguay). Within the EPPO region, the species is grown as an ornamental tree and it has an impressive flowering stage before the development of new leaves. In Sicily, the species is commonly grown as an ornamental species in urban streets in Palermo though its introduction is relatively recent: the species was introduced in 1982 from seed from Argentina. From observations between 2013 and 2018, natural regeneration has been observed within the campus of the University of Palermo. The survey area is a row of street trees approximately 50 m in length and more than 50 seedlings have been recorded growing along the pavements and 3 seedlings were observed growing out of water drains. The furthest individual from the mother plant was growing 15 m away growing out of a water drain. The authors conclude that H. heptaphyllus should be considered as a casual alien species in Sicily and it may spread and become established within urban environments.
Sources
Badalamenti E, La Mantia (2018) Handroanthus heptaphyllus (Bignoniaceae) in Sicily: a new casual alien to Italy and Europe. Flora Mediterranea 28, 331-338.