Essential oil composition of two variants of Prostanthera lasianthos Labill. from Australia

The essential oils from the leaves of two variants of Prostanthera lasianthos Labill. have been analysed by GC and GC/MS. The different samples studied showed two chemotypes, the rheophytic variant, chemotype 1,8-cineole and β-pinene and the smooth-leaved variant with the chemotype linalool, linalyl acetate and β-selinene. The percentage composition of these compounds were 57.3–66.0%, 9.2–10.2%, 13.8–24.6%, 13.8–19.1% and 7.8–14.2%, respectively. One of the samples (P.l.n2) showed intermediate values so it could be a hybrid although it was morphologically similar to smooth-leaved variant. According to our chemical results and previous morphological studies we think that both variants could be recognised as distinct taxa level (subspecies or species) although further genetic research should be done to confirm this hypothesis.