ABSTRACT
The volatile oils composition of stems, leaves and flowers of Ducrosia flabellifolia Boiss. from northern border of Saudi Arabia were investigated by gas chromatography coupled with mass spectrometry. A total of 52 compounds have been identified from the different fractions studied, representing about 90% of total oil of each one. Aerial parts shared most of the main components although qualitative and quantitative differences have been detected. Decanal and dodecanal could be considered as chemical markers of this species, where they were representing 58.8% , 64.84% and 66.46% of stems, leaves and flowers oils, respectively. The aldehyde hydrocarbons fraction was predominant in stems (65.11%), leaves (65.39%) and flowers (67.3%), followed by the monoterpenes hydrocarbons fraction in Leaves (9.37%) and flowers (5.53%) and Oxygenated sesquiterpenes in stem (10.83%).