Natural selection drives leaf divergence in experimental populations of Senecio lautus under natural conditions

• Leaf morphology is highly variable both within and between plant species. This study employs a combination of common garden and reciprocal transplant experiments to determine whether leaf shape in Senecio lautus has evolved as an adaptive response to divergent natural selection. • We created a synthetic population of hybrid genotypes to segregate morphological variation between three ecotypes, and performed reciprocal transplants where this hybrid population was transplanted into the three adjacent native environments. We measured 9 leaf morphology traits across the experimental an natural populations at these sites . • We found significant divergence in multivariate leaf morphology toward the native character in each environment, suggesting environmental conditions at each site exert selective pressure that results in a phenotypic shift towards the local phenotype of the wild populations.• These associations suggest that differences in leaf morphology between S. lautus ecotypes has arisen as a result of divergent selection on leaf shape or associated traits that confer an adaptive advantage in each environment, which has led to the formation of morphologically distinct ecotypes.