Significant shift in trade-offs between native and introduced populations. A Relationship between vegetative height at first flower bud (cm) and number of days to flowering for Sonchus oleraceus populations in the native range (West Palearctic, blue) and in the introduced range (Oceania, orange). Regression estimates for native plants: y = 2.35 x – 102.95 and for introduced plants: y = 1.18 x - 33.43. The interaction is significant (LRTχ2 = 12.35, df = 1, p < 0.001). The shaded area represents the standard error of the mean. B Relationship between leaf-stem biomass (g) and grain yield (g) for Sonchus oleraceus populations in the native range (West Palearctic, blue) and in the introduced range (Oceania, orange). Regression estimates for native plants: y = -0.63 x + 9.01 and for introduced plants: y = -1.27 x + 10.84. The interaction is significant (LRTχ2 = 6.81, df = 1, p < 0.01). The shaded area represents the standard error of the mean.