Abstract In three commercial celery (Apium graveolens L.), seed oil samples were analyzed by GC/MS; a sesquiterpene ether, kessane, was detected in varying amounts from 2.2â7.6%. Forty-two other constituents were identified, with limonene (50.1â65.5%) and Î²-selinene (11.2â22.2%) being the major components.