Variations in Essential Oil Compositions of Lavandula pubescens (Lamiaceae) Aerial Parts Growing Wild in Yemen.

Lavandula pubescens Decne. is one of five Lavandula species growing wild in Yemen. The plant is used in Yemeni traditional medicine, and the essential oil tends to be rich in carvacrol. In this work, L. pubescens was collected from eight different locations in Yemen, the essential oils obtained by hydrodistillation, and the oils analyzed by gas chromatography/mass spectrometry (GC/MS). Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were used to differentiate between the L. pubescens samples. The essential oils were rich in carvacrol (60.9 - 77.5%), with lesser concentrations of carvacrol methyl ether (4.0 - 11.4%), caryophyllene oxide (2.1 - 6.9%), and terpinolene (0.6 - 9.2%). The essential oil compositions in this study showed very high similarity, but it was possible to discern two separate groups based on minor components, in particular the concentrations of terpinolene, carvacrol methyl ether, m-cymen-8-ol, and caryophyllene oxide.