Abstract The composition of the essential oil obtained from the dried aerial parts of Eupatorium cannabinum L. (Compositae) was analyzed by GC and GCâMS. Fortyâseven components were identified in this oil. The major constituents of the essential oil were α âterpinene (17.8%), germacrene D (9.1%) and thymol methyl ether (5.2%). The essential oil of the aerial parts of E. cannabinum is rich in sesquiterpenoids. Copyright © 2006 John Wiley &amp; Sons, Ltd.