abstract essential oils obtained by hydrodistillation from two endemic centaurea species (c. aphrodisea boiss. and c. polyclada dc.) and three widespread (c. athoa dc., c. hyalolepis boiss. and c. iberica trev. ex sprengel) centaurea l. (asteraceae) taxa from turkey were analyzed by gas chromatography (gc) and gc/mass spectrometry (gc/ms) techniques. the analyses revealed 109 constituents, accounting between 87% and 93.4% of the oils. hexadecanoic acid (8.1-27.9%) was the main constituent of c. iberica, c. hyalolepis and c. polyclada oils, while spathulenol (8.1%) was the major compound in c. aphrodisea and caryophyllene oxide (17.1%) in c. athoa oils. keywords: centaurea asteraceaeessential oil compositionhexadecanoic acidcaryophyllene oxide acknowledgements we thank serdar senol (section of botany, department of biology, faculty of science, ege university, izmir, turkey) and dr. dr. esat cetin (department of biology, faculty of science, harran university) for their helps for collection and identification of the plant materials.s