Abstract: Knowles was selected from hybrid populations resulting from crosses between meadow bromegrass (Bromus riparius Rehm.) and smooth bromegrass (Bromus inermis Leyss.). It has a unique array of plant characteristics, some similar to meadow bromegrass, and others more similar to smooth bromegrass. In regional trials, Knowles produced hay yields greater than meadow brome, but lower than smooth bromegrass. It was superior to smooth bromegrass in regrowth after cutting. For steer grazing performance, Knowles was equal or superior to its parental species, perhaps due to its lower fiber concentrations at vegetative growth stages. Key words: Hybrid bromegrass, Bromus riparius × Bromus inermis, cultivar description