ANATOMICAL features of stem and leaf have been studied on four endemic species collected from St. Catherine area, S. Sinai, Egypt. viz. Silene leucophylla Boiss., S. oreosinaica, S. schimperiana and Bufonia multiceps which is provided for the first time. Comparative study was conducted using both light microscope (LM) and scanning electron microscopy (SEM), based on the anatomical structure of the leaf and stem. Druses were found abundantly in both leaf and stem tissue in studied Silene taxa, absent in Bufonia multiceps. Stomata were mostly diacytic or both diacytic and anomocytic were also recorded. Surface view of epidermal cells were straight or undulated. Epicuticular wax platelets have been observed on epidermal and guard cells of S. schimperiana and S. leucophylla. The leaf epidermal and stem anatomical characters were found distinct in each species. Artificial key was provided for the identification of the studied species.