Typification of names allied to Centaurea ambigua (Asteraceae) from the Apennine Peninsula (Italy)

A contribution to the nomenclature of the Italian endemic Centaurea ambigua is presented. A survey of original material for the names applied to the three currently accepted subspecies (C. ambigua subsp. ambigua, C. ambigua subsp. laciniata, C. ambigua subsp. nigra) was performed. Lectotypes for five names based on specimens preserved at FI, G and NAP are designated: C. ambigua, C. dissecta var. macrocephala, C. dissecta var. melanocephala, C. dissecta var. nigra, and C. laciniata. Finally, C. ambigua subsp. laciniata, actually considered a subspecies narrowly endemic to Abruzzo (central Italy), is proposed here as a heterotypic synonym of C. ambigua subsp. ambigua.