The yields of essential oil were 0.09% for the flowers, 0.12% forthe fruits and ranged from 0.25 to 0.50% for the leaves. It was veri-fied the presence of sesquiterpene hydrocarbons (73.72%, flowers;75.17%, fruits; 81.87–95.12%, leaves); oxygenated sesquiterpene(25.84%, flowers; 17.83%, fruits; 4.88–17.04%, leaves). Twenty nineconstituents were identified in the essential oil of flowers of H.oreadica, being the major components the amorpha-4,7-(11)-diene(29.27%) bicyclogermacrene (23.28%) and pogostol (20.68%); thirty constituents were identified in the essential oil of the fruit andthe major components were the same of flowers (20.26; 20.64 and9.95% respectively) and -muurolene (9.24%); 21–28 constituentswere identified in the essential oils of the leaves and the major