First record of Sphaeralcea bonariensis (Cav.) Griseb. (Malvaceae) as a casual alien species in the Mediterranean area

Sphaeralcea bonariensis (Cav.) Griseb. is here reported for the first time as alien species in Italy and in the Mediterranean area. It is a perennial shrub native to Southern America, where it is often considered a ruderal species frequent in cultivated areas. It was found in a population of a few individuals within Opuntia ficus-indica groves of Rocca Palumba territory (Western Sicily). Actually, due to short-term observational period and the low number of plants, Sphaeralcea bonariensis should be considered as a casual species in Italy. The ecological characteristics of the growing stand and the consistency of the population, as well as the possible causes of its introduction, are briefly discussed.