A new grass taxon in the Phleum pratense group (Poaceae) from the islands of Limnos and Lesvos (North Aegean, Greece)

Phleum pratense subsp. boreoaegaeum is described as a taxon new to science. It was found in wet-dry grassland in two localities on the island of Limnos (Lemnos) and one on the island of Lesvos (Lesbos) (North Aegean, Greece). Morphology, habitat and population size were noted, and the ploidy level was established using flow cytometry. Diagnostic features against the related members of the P. pratense group showed an intermediate position of the new taxon between the diploid P. nodosum and the hexaploid P. pratense . In terms of spikelet morphology, P. pratense subsp. boreoaegaeum is most similar to P. pratense s. str., while in terms of genome size, it corresponds to P. nodosum . When applying IUCN Red list criteria, the new taxon must be considered Vulnerable. Its locality and habitat on the islands are currently only partly protected. Apart from targeted conservation efforts and monitoring it is recommended that karyological and genetic studies be conducted on the new grass taxon to investigate its possible role in the origin and evolution of P. pratense .