Although invasive exotic plants have only relatively short residence times in their new regions, there is evidence that populations have become phenotypically differentiated within the invaded range, particularly along latitudinal (climatic) clines. This differentiation is likely to reflect local adaptation. However, as many invasions might have started from small populations with limited genetic variation, the mechanism of rapid adaptation in invasive organism is frequently unknown. In theory, epigenetic variation and inheritance provide a possible mechanism that may contribute to rapid adaptation, but it has still received relatively little empirical attention in evolutionary ecology. Here, we propose to study the role of epigenetic mechanisms in rapid adaptation of invasive plant species. To this aim, we will do common-garden experiments using seed material of Solidago canadensis and S. gigantea collected along a latitudinal transect in Germany and use a de-methylation agent to remove potential epigenetic fingerprints. In addition, we will use AFLP and methylation sensitive AFLP markers to test for genetic and epigenetic latitudinal patterns. Moreover, in reciprocal transplant experiments, with and without the application of a de-methylation agent, we will test for multiple invasive and co-occurring native species the contribution of epigenetic mechanisms to local adaptation.