Chemical composition of the essential oil of Achillea umbellata growing in Greece.

The essential oil of the aerial parts of the endemic Achillea umbellata (Compositae) was obtained by hydrodistillation and analysed by gas chromatography (GC) and gas chromatography coupled to mass spectrometry (GC-MS). Sixty-six constituents were identified. The major constituents of the oil were beta-thujone (62.8%) and camphor (8.7%).