AbstractOrganisms rely on plasticity to track environmental variation within their native range. However, it remains unclear how adaptation and plasticity interact, and how adaptive divergence affects the evolution of plasticity. To test for variation in plastic responses among two closely related but ecologically divergent ragwort species (Senecio, Asteraceae), we sampled c.40 genotypes of each species from natural populations. We then transplanted multiple clones of each genotype into four field sites along an elevational gradient representing each species’ native range, the edge of their range, and conditions outside their native range. At each transplant site, we quantified survival, growth, leaf investment, leaf morphology, chlorophyll fluorescence and gene expression. Both species performed better at their home sites, but the high elevation species showed lower tolerance to conditions outside its range than the low elevation species, suggesting stronger specialisation to the high elevation habitat. The two species also differed substantially in the direction of phenotypic and gene expression change across elevation, suggesting that distinct plastic responses have rapidly evolved in these two species. Adaptive divergence has led to the evolution of distinct plastic responses to environmental variation with distinct genomic architectures, despite these two species having shared a recent common ancestry.