Because there is no group of plants generally recognized as “eXtreme mesophytes”, genome level resources will need to be sought independently for each species.
For Solanum dulcamara (bittersweet) –
A transcriptome was first published in 2013 by the B’sweet project at Radboud University, using next generation sequencing. The associated files can be downloaded either from the European Nucleotide Archive or NCBI. A reference genome project was also registered at NCBI in 2017 although no results have been submitted (as of April 2019). The following links will lead to the most current listings at NCBI: