The article presents a concise history of systematic studies on taxa included in the section Phleum of the genus Phleum. The authors discuss the results of cytotaxonomic studies within the section which have been conducted so far and their importance for studies of phylogeny of particular species. It is suggested that the section should be divided into five species on the basis of karyosystematic criteria considering the karyotype structure as well as localization of heterochromatin in the genome. The question of origin of two polyploid species (P. commutatum Gaud. and P. pratense L.) is also discussed.