Revision of the <i>Festuca marginata</i> “group” (<i>Festuca</i> sect. <i>Festuca</i>, Poaceae) in Southern Europe, with special reference to France, Italy and Greece

The Festuca marginata group includes several taxa of glaucous, thick-leaved fescues with three sclerenchyma strands, first described by Hackel as Festuca ovina subsp. laevis, which are common in the Euro-Mediterranean area. Ten different taxa (species and subspecies) are currently recognized in this group. Nevertheless, taxonomical works typically have only a local (mostly national) scope, and the recognized taxa show only few or negligible morphological differences, making their separate taxonomic status doubtful. Here we provide morphological, karyological, and genetic analysis (ISSR, flow cytometry) of the Festuca marginata group based on populations in a larger geographical scale including Central and Southern-Eastern Europe. We found that most of the local taxa are difficult to definitively distinguish and we suggest the whole group be treated as a single species, Festuca marginata, with two subspecies reflecting major differences in morphology and genome size between the Greece subsp. heldreichii and the remaining European populations, referred to as subsp. marginata.