Molecular phylogeny of RNA polymerase II gene reveals the relationships of tetraploid species with St genome (Triticeae: Poaceae)

► R. magnicaespes and R. alashanica were closely related to Pseudoroegneria. ► R. elytrigioides should be classified as Pse. elytrigioides. ► Pse. tauri and Pse. deweyi should be transferred to Douglasdeweya and named as D. wangii and D. deweyi. ► Pse. geniculata ssp. scythica and El. caespitosa ssp. nodosa should be identified as species of Trichopyrum. ► Roegneria, Douglasdeweya and Trichopyrum were valid genus.