First record of Klasea quinquefolia (M.Bieb. ex Willd.) Greuter & Wagenitz (Asteraceae) in Italy

Klasea quinquefolia (M.Bieb. ex Willd.) Greuter & Wagenitz is a perennial and rhizomatous herb native to the Russian Caucasus, Armenia, Azerbaijan, Georgia, Iran, and Asian Turkey. The natural habitats of the species are deciduous forests or open areas in hill/mountain areas. Outside the native range, the species is mainly known for its ethnobotanical and pharmaceutical uses but in recent years, it has been also recorded as an alien species in Austria. In this work, we reported the first occurrence of K. quinquefolia in Italy. The species was recorded in August 2023 in the Monza Park (Lombardy, N-Italy) in a mesophilous woodland dominated by Carpinus betulus. The new population was subdivided in 10 subpopulations distributed in habitat patches with surface areas ranging from 0.085 to 95,008 m2. The total population accounted almost 500 individuals with a flowering population size of about 350 individuals. Likely, the establishment of K. quinquefolia is linked to the presence of internationally frequented facilities that might have favoured its unintentional arrival (e.g. the Monza Racetrack) or to historical reasons of past introductions to Royal Gardens of the Monza Palace. Presently, it should be treated as a naturalized alien species in Italy even if its further spreading could be favoured by the species' habitat preference and climate change.