The systematics of the genus Arundo (Poaceae) remains poorly resolved because of the overlap of morphological characters classically used in the taxonomy of the genus and insufficient variation of DNA sequences. The main aim of this study is to delimit genetic clusters with AFLP
fingerprints and to compare them with morphological data. On the basis of extensive sampling in the Mediterranean area, AFLP markers clearly showed five clusters. Despite overlapping values, morphometric analyses strongly confirm these clusters, and new qualitative features allow the recognition
of five taxa: the Taiwanese A. formosana, the cosmopolitan A. donax, the circum-Mediterranean A. micrantha, the Italo-Balkan A. plinii and the Franco-Ligurian A. donaciformis (Loisel.) Hardion & al. comb. nov. Additionally, this study shows a correlation
between genetic diversity, caryopsis production and ploidy level. However, the lack of genetic diversity for A. micrantha and A. donax in the Mediterranean area remains enigmatic.