Karyotypes of five taxa (fourteen populations) of the genus Bromus from different geographic origins is presented: B. scoparius, B. japonicus, B. madritensis, B. rubens and B. tomentellus. The ploidy levels were different. B. scoparius and B. japonicus were found 2n=2x=14, B. madritensis and B. rubens were found 2n=4x=28 and B. tomentellus were found 2n=6x=42. Detailed karyotype analysis allows us to group the different populations and to postulate relationships among them.
