SUMMARY
Some endemics taxa of the Pyrenees and of the southern Alps have been found in the southern Vercors. It allows to think that this country might be an area of refuge during quaternary glaciation, but also a place of post-glacial new settling. The being of Pyreneans elements suggests that this new settling might happen from the Pyrenees.
Caryological studies don't allow to divide some taxa of different phytosociological and geographical origin.