Climatic characterization of Bromus tectorum genotype source collection sites (n = 92) and common garden sites (n = 4). (a) Genotype source locations colored by their value along the principal component (PC) 1 climate axis, where high values of PC 1 = hot and dry, and low levels of PC 1 = cool and wet. Common garden sites are denoted as unfilled, larger shapes. (b) Genotype source locations colored by their value along the PC 2 climate axis, where high values of PC 2 = more pronounced temperature seasonality, and lower values of PC 2 = less pronounced seasonality. (c) Common garden sites classified by their longitude (x‐axis), elevation (y‐axis), value along the PC 1 axis (outer color) and PC 2 axis (inner color). Genotype source locations are overlaid as small gray points. BA, Baltzor; CH, Cheyenne; SS, Sheep Station; WI, Wildcat.