The focus of this study is based on the examination of the germination traits and the development of thermal models of the medicinal plant Salvia leriifolia Benth. A laboratory experiment was carried out at constant temperatures ranging from 0 to 35°C, at 5°C intervals in a completely randomized design with eight replications. To describe the germination rate response to temperature, three regression models, namely Intersected-Lines (ISL), Quadratic Polynomial (QPN) and Five-Parameters Beta (FPB) were used. The highest Germination Percentage (GP) (92.8%) occurred in 15°C, but GP in the range of 10–25°C was not significant (p≤0.05). The germination process stopped at 0°C and at above 30°C. The results indicated that the highest Germination Rate (GR), the lowest Mean Germination Time (MGT) and also times to 50% germination (D50) were obtained at 20°C. Seeds did not reach to their 50% germination level in temperatures higher than 25°C. The FPB model had the best realistic estimation for cardinal temperatures. Based on models estimation, Base (Tb), Optimum (To) and Ceiling (Tc) temperatures were in the ranges of (1–1.9°C), (18.1–20.8°C) and (34.5–38.7°C), respectively.

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