Considerations and distributional innovations for some taxa of the genus Parapholis (Poaceae) in the Adriatic basin with special reference to Parapholis strigosa, for which a new infraspecific taxon is proposed

The distribution of Parapholis strigosa (Dumort.) C.E.Hubb. in the Adriatic basin has been analysed. After the investigations by Hylander and Runemark, further collections were made, particularly during the years 1991-2002, and in 2017-2018 limited to Albania, that revealed the presence of an important population over the entire basin, which was especially dense along the northwestern coasts. These studies, together with revision of the historical material gathered from the area and conserved in various Italian and foreign herbaria, highlighted a quantitative morphological character of clearly genetic origin, already considered as diagnostic within the genus. This trait, anther length, falls into two distinct size classes, their values constant within different areas of the basin, in turn characterised by different geological and climatic situations. It was thus possible to establish a new intraspecific taxonomic entity named Parapholis strigosa var. minor, var. nov., although the variability was significant the t-Test (p<0.0001). This distribution showed the new variety, occurring on the western (Gargano lakes) and eastern coasts (Dalmatia and Albania) both with a Mediterranean climate, to be almost entirely separated from the typical form, with only one point of overlap. The autonymic variety, on the contrary, is found along all the other coasts with a temperate climate. Moreover, on other revised material brought to light, the first report of Parapholis marginata Runemark for Montenegro and, the northernmost station in the temperate area of the Mediterranean for the same taxon.