Abstract
From 1960 to 1989 more than 80 Thymus taxa from 27 different countries all over the world have been investigated for the composition of their essential oils. About 200 different compounds, mostly terpenes, have been identified. The terpene phenols thymol and carvacrol represent the most important compounds in the genus, followed by linalool, p-cymene, γ-terpinene, borneol, terpinen-4-ol and 1, 8-cineole. This paper lists the main components of the essential oils of all the taxa investigated from 1960 to 1989. In addition, seasonal variations of Thymus oils and essential oil polymorphism within the genus Thymus are also reported.