Roegneria heterophylla, a New Combination for Roegneria (Poaceae, Triticeae) from Lebanon

Agropyron panormitanum Parlatore var. heterophyllum Bornmüller ex Melderis (Poaceae, Triticeae) is transferred to the genus Roegneria K. Koch based on its ploidy and genome. The taxon was described from Lebanon and is recognized at species rank as the new combination R. heterophylla (Bornmüller ex Melderis) C. Yen, J. L. Yang & B. R. Baum. The taxon is hexaploid, with the StStStStYY genome, and therefore its taxonomic relationship is better reflected and assessed within the genus Roegneria, a genus with genomic constitution StStYY or StStStStYY. Furthermore, it should be treated as a new species rather than as a variety because the two have separate and independent gene pools as demonstrated by crossing experiments.