The essential oils of two endemic Teucrium species from Madeira: T. abutiloides L'Hér. and T. betonicum L'Hér

The essential oils isolated by hydrodistillation from aerial parts of Teucrium abutilodes L'Hér. and of T. betonicum L'Hér. were obtained in almost similar yields (<0.5%). The oils were complex mixtures consisting mainly of sesquiterpene hydrocarbons, which amounted to 55% of the oil of T. abutiloides and to 45% of that of T. betonicum . However, large differences, both qualitative and quantitative, were observed with regard to the fraction of sesquiterpenes of these oils. Germacrene‐D (13%) and δ‐cadinene (11%) were the most abundant sesquiterpenes in the oil of T. abutiloides , and β‐caryophyllene (12%) in that of T. betonicum . Oct‐l‐en‐3‐ol was the main component of both oils (20% of the oil of T. abutiloides and 24% of that of T. betonicum ).