Commelina virginica. a North American xenophyte recorded in the Euro-Mediterranean area since the late 19^th century, is excluded from the flora of this region. As a result of extensive literature and herbarium research, all the records of this species proved to be erroneous and referable mostly to C. communis. The first historical and misleading record of C. virginica is discussed in detail and the diagnostic morphological features actually accepted to distinguish the two species are reported.