abstract the essential oils obtained from the aerial parts of hippomarathrum microcarpum and physospermum cornubiense, growing in iran, were analyzed by gc and gc/ms. thirty-three compounds representing 95.2% of the oil of h. microcarpum, and nine compounds representing 91.5% of the oil of p.cornubiense were charactrized. the major components of the oil obtained by hydrodistillation from h.microcarpum were -pinene (15.9%), -caryophyllene (15.7%), -phellandrene (7.8%) and germacrene-d (6.8%) and the major components of the oil of p. cornubiense were caryophyllene oxide (27.5%), limonene (16.2%) and -caryophyllene (15.8%).