Arctotheca calendula: an emerging invasive alien plant in Italy
Arctotheca calendula (Asteraceae: EPPO List of Invasive Alien Plants) is a short lived herbaceous plant which was first introduced into Europe as a garden ornamental in the early 18th century. Native to South Africa, A. calendula has been recorded in France, Israel, Italy, Morocco, Portugal, Spain and Tunisia. In Italy, A. calendula was recorded for the first time at a camping site on the island of Lipari (Sicily) and now the species occurs in the Campania, Calabria, Sicily and Sardinia regions. In Sardinia, A. calendula survives on three different habitat and land use types which include ploughed pasture land, intensive agricultural land and disturbed garrigue. Further spread is likely and the warmer Italian regions which comprise the Mediterranean bioclimatic division are most at risk of invasion by this species. A. calendula is also spreading in other EPPO countries including Morocco, Tunisia and Israel where spread is facilitated by movement of machinery, soil and livestock. In the USA, A. calendula is classified as a noxious weed and in Australia the species invades a number of cropping systems where it has negative impacts on yields. Ecological impacts associated with the species include competition with native species for space and water resources. In Spain, ecological impacts have been recorded where the species has been reported to penetrate valuable and vulnerable coastal dune systems.
Sources
Brundu G, Lozano V, Manca M, Celesti-Grapow L, Sulas L (2015) Arctotheca calendula (L.) Levyns: An emerging invasive species in Italy. Plant Biosystems 149, 954-957.