📓 This book addresses the ecology of three medicinal plant species: Origanum syriacum, Teucrium polium, and Verbascum sinaiticum. This book include an ecological assessment for the distribution behavior of these three species in the Sinai mountains with attention paid to the environmental factors affection the distribution with using multivariate techniques clarifying the relationship between the species and environmental conditions. The book also include a full description for soil analysis for the most common habitats and detailed explanations for the main threats affecting the occurrence of these medicinal plants. The work is supported with a species list of all associated to these medicinal species and more information about seed germination and seed storage behavior for studied species, in addition to the equilibrium moisture content and moisture isotherms and its variation among populations. Finally the book introduce a conservation plan for these important medicinal plant to protect them from extinction in south Sinai.