Phenotypic diversity of Aegilops cylindrica (jointed goatgrass) accessions from the western United States under irrigated and dryland conditions

► Hybridization between wheat and the invasive weed jointed goatgrass is a risk for gene introgression. ► A field study of U.S. jointed goatgrass collections was conducted in Colorado, USA under two moisture treatments in two years. ► Phenotypic diversity for competitive ability and fitness traits was shown across collections and water treatments. ► A significant interaction between collection and water treatment was observed in one year of the study. ► Phenotypic diversity suggests that the effects of gene introgression may vary by population and environmental conditions.