the number of leaves per node is strongly increased, which leads to the formation of several nearly closed vertical furrows on the shoot, where stomata are shaded and strongly encrypted. Thus, the adult foliage shows several xeromorphic features that are absent in the juvenile foliage. Our morpho-anatomical data mapped on ecological and palaeobotanical data show that within Casuarinaceae the foliage shifted from scleromorphic to xeromorphic. Thus, the adult xeromorphic foliage in Casuarina is the derived, advanced state.