Summer savory (Satureja hortensis L.), a member of the Lamiaceae family, is an important vegetable crop and medicinal plant, widely used both as food and as an herbal remedy. In the present study, the phenotypic diversity of 29 Iranian landraces was evaluated based on plant height, stem length, root length, internode length, number of leaflets per main stem, leaf area of leaves on the main stem and lateral branches, fresh weight of stem, root and whole plant, dry weight of stem, root and whole plant, and essential oil content. Factor analysis revealed that 89% of the observed variation could be explained by the first five factors, which were characterized based on varimax-rotated scores as biomass, dwarfism and leaflet traits, leaf area, low essential oil content, and reduced root length. A plot of the first two factors, accounting for 62% of the total variation, distinguished five genotypic groups. Notably, Group C genotypes - G6 (Sistan), G15 (Hamadan), G23 (Arak), and G27 (Tonkabon-A) - exhibited high biomass and essential oil content, making them promising candidates for cultivar development and future breeding programs. To classify the traits, a two-dimensional plot based on the first two factors was generated. This analysis showed that internode length, plant height, stem length, and the leaf area were grouped together. Similarly, root length, number of leaflets per main stem, and essential oil content were clustered together, while the remaining traits constituted a separate cluster. Overall, this study revealed considerable genetic diversity among Iranian summer savory landraces based on morphological traits, providing valuable information for germplasm conservation and efficient selection in breeding programs.
