5 CONCLUSION
The genus Ionopsidium is adapted to hot and dry Mediterranean conditions, whereas Cochlearia species largely prefer cold habitats. However, all species evaluated in this study exhibited similar and severe cold responses. Whether this similarity has resulted from an evolutionary adaptation of a common ancestor of the two taxa or from parallel evolution is unclear. However, the results of the present study indicate that adapting to different stressors, such as salinity and drought, also confers tolerance to cold, as all these stressors induce osmotic challenges. From a present-day perspective, all taxa were subjected to higher temperatures (Ionopsidium and C. danica ), and eventually accelerated drought stress was adapted to at a macroevolutionary scale with monocarpic growth. This pattern was more widely distributed in the entire Brassicaceae family (e.g., tribe Arabideae; Karl xxx), which, therefore, might indicate a more general evolutionary path to temporarily escape from a changing environment towards increasing temperature and drought. However, this also leads to a pessimistic scenario for the long-term survival of various polycarpic Central European Cochlearia species.