Composition of the Essential Oils from Two Populations of Achillea millefolium L. ssp. millefolium

The composition of the essential oils isolated from the flower heads, in different stages of development, from two populations of Achillea millefolium L. ssp. millefolium, growing in the Botanical Garden of Lisbon (BGL) and in the Caneco Garden of Almada (CGA), respectively, is analyzed by GC and gas chromatography-mass spectroscopy (GC-MS). The plants of the CGA originated from explants of the BGL. Although the monoterpene fraction is dominant in all the oils analyzed (ca 80%), the main components differ: sabinene and 1,8-cineole are dominant in the oils isolated from the plants of the BGL, whereas camphor, 1,8-cineole, and β-pinene are the main constituents of the oils from the plants of the CGA. Germacrene-D is the major component of the sesquiterpene fraction of all the oils analyzed. The relative amounts of the oil components show fluctuations during the development of the flower heads. Chamazulene is only detected in the oils from the flower heads collected in the CGA; its amount decreases through flower-head development