This book deals with the plant diversity of Omayed Biosphere Reserve as a Mediterranean Biosphere Reserve in Egypt. Since 1974, Omayed biosphere reserve has subjected to intensive and extensive surveys and analyses covering almost all the biotic and abiotic components of its ecosystems. It contains 251 plant species: 131 perennials and 120 annuals. These flora belong to 169 genera and 44 families. Among these species, one is endemic, 40 are rares (23 perennials and 17 annuals), 19 are noteworthy species and 11 threatened species. Fifty-eight species are woody plants (mainly shrubs) contibuting about 23.1% of the total species (10 phanerophytes and 48 chamaephytes).