Use of morphometric data for the evaluation of the essential oil content of wild growing Thymus L. plants

The plants of the genus Thymus L. hold a significant position in the global medicinal and aromatic plants market, largely due to their Essential Oils (EOs). International, European and Greek specifications for quality screening of plants commercially distributed as “thyme” include, amongst other, the minimum value of EO content (mL 100g-1 dry weight). In the present study an attempt has been made to evaluate the EO content of wild growing Th. sibthorpii Benth. plants through morphometry. The comparison of morphometric data to the results acquired by the hydro-distillation method showed that the EO content of a plant individual may be evaluated using the number and diameter of glandular scales on leaves’ surface.