Contribution to the Knowledge of Leontodon Sect. Asterothrix (Cass.) Ball in Italy and on the Balkan Peninsula

In order to better understand the <i>Leontodon crispus</i> group within <i>L.</i> sect. <i>Asterothrix</i>, we collected specimens belonging to this group during several journeys to the Apennines and the Balkan Peninsula, especially to Croatia, Albania, and Greece. In the present contribution, <i>Leontodon biscutellifolius</i> is lectotypified; the <i>locus classicus</i> of this taxon is located in the Abruzzo Mts (central Italy). As a consequence, the taxon is confirmed for the Italian flora (central and southern Apennines) and a new combination on variety rank is proposed: <i>L. crispus</i> var. <i>biscutellifolius</i>. Plants from the Balkan Peninsula, currently named <i>L. biscutellifolius</i>, were compared from a morphological point of view with the Apennines populations. Balkan populations show denser indumentum on the leaves, usually consisting of 4-fid hair vs. usually 3-fid hairs in the Apennines. Additionally, the ray number of marginal hairs on the external involucral bracts was found to be 3-5 in the Apennines vs. 4-6 in the Balkan Peninsula accessions. Morphological variation was found to be in correspondence with a variation in genetic respects based on DNA-based fingerprinting (AFLPseq). The oldest subspecific name that can be used for Greek and Albanian populations is <i>L. crispus</i> subsp. <i>asper</i>. A morphologically and genetically deviating population from Southern Pindus (Greece) is described here as <i>L. hellenicus</i> subsp. <i>valeriae</i>.