Genetic differences as the basis for selection and evolution in all organisms is well documented, while the role of epigenetic diversity is more hypothesized than experimentally proven. The essential insights into epigenetic mechanisms gained in plant science let it appear obvious to address the questions, (1) whether and how information outside of the DNA sequence can influence phenotype and fitness and (2) if environmental factors can change epigenetic features and generate epialleles. The originally proposed Collaborative Research Project was developed by five European experts in epigenetic, ecological and ecogenomic research. They will join forces, using their established methodology, to deliver proof of concept for the role of epigenetics in plant adaptation to environmental change. Work with the inbreeding species Arabidopsis thaliana, with a plethora of genetic, epigenetic and genomic information and available in numerous accessions from different habitats, will be complemented by experiments with Scabiosa columbaria, an outbreeding species for which consequences of habitat fragmentation and inbreeding depression are well documented. Well characterized plant material will be analyzed for epigenetic diversity, subjected to controlled environmental conditions and studied in subsequent generations. Epigenetic analysis will comprise DNA methylation and chromatin modifications on individual sequences as well as whole genomes. The project is expected to result in a better understanding of the extent, significance and generality of epigenetic variation as an additional mechanism for plant adaptation. In the light of significant environmental changes in close future, it might help increasing the weight of European research in this field.