Different chromosome numbers but slight morphological differentiation and genetic admixture among populations of the <i>Pulmonaria hirta</i> complex (Boraginaceae)

Hybridization and introgression have a significant impact on the taxonomically controversial genus Pulmonaria. Within this genus, P. hirta complex shows puzzling systematic relationships among s.str. (2n = [22, 26] 28), apennina 22 [26]), vallarsae 22), showing range overlaps mixed phenotypes in southern Europe. We carried out morphometric analyses of basal leaves flower features along with AFLP characterization 236 plants belonging to 11 populations within 1 population officinalis. also implemented an already available phylogeny sequences from our target characterized their karyotype. For all complex, we found molecular evidence hybrid origin involving species different clades (angustifolia officinalis clades). However, there is certain morphological differentiation between some (“hirtoid” morph) others (“vallarsoid” morph), albeit single individuals or entire show intermediate features. According results, hybridization and/or backcrossing/introgression occurred, gene flow currently taking place these “taxa”. Following event(s), can elaborate three possible evolutionary scenarios: (1) one “vallarsoid” 22) spread across Italian peninsula, originated “hirtoid” morph 28) through dysploidy; (2) two geographically distinct events produced both morphs; (3) alloploid backcrossed generating plants. Under scenarios 2, morphs met again central Italy, massive current flow. scenario 3, but further leaving pure lineages only extreme north south range. This latter supported by 2n 22, 26 chromosomes, having karyotype asymmetry indices those 16 28 cytotypes. Irrespective dynamics, today, lineage cytotypes occurs throughout supporting circumscription polymorphic species, namely hirta.