Abstract
A natural hybridization in grasses (Poaceae) frequently occurs in the area where the distribution ranges of parental species overlap (e.g. Smith 1942, Tzvelev 1976, Soltis & Soltis 2009, Nobis 2013, Nobis et al. 2017, Wölk & Röser 2017). Such phenomenon can be observed also in the genus Festuca Linnaeus (1753: 73) between Festuca ovina Linnaeus (1753: 73) and Festuca polesica Zapałowicz (1904: 303) that distribution ranges overlap. The hybrid individuals are morphologically intermediate between those of the parental species and can be easily distinguished by leaf anatomy (Bednarska 2009). In 2009, the first author of the present paper described this hybrid as a nothospecies Festuca ×polovina Bednarska (2009: 32), providing a protologue in Latin with a detailed description of the taxon, indication of diagnostic characters, and a list of herbaria where the holotype and isotypes are stored. However, no direct citation of a particular herbarium specimen was provided for the nomenclatural type as required by Art. 40 of the ICN (McNeill et al. 2012), and hence the name F. ×polovina was not validly published.