Comparative investigations of the essential oils of two scented geranium (Pelargonium spp.) cultivars grown on Reunion Island

The essential oils of two scented geranium (Pelargonium spp.) cultivars grown on Reunion Island were investigated by GC–MS. The specific odour attributes of each single constituent were correlated with the olfactory impression of the two essential oils. The scent of the essential oil extracted from the well‐known rose‐scented geranium cultivar, Pelargonium cv. Rosé, is based on the rosy, fruity, minty and faintly citrusy aromas of the main components, citronellol (21.9%), geraniol (18.3%), linalool (16.0%), citronellyl formate (11.6%) and isomenthone (7.6%), accompanied by minor compounds of olfactory significance, including geranyl formate (4.0%), nerol (1.7%), geranyl tiglate (1.6%) and neryl propanoate (1.5%) in particular. The volatile constituents of the essential oil of a second geranium cultivar (Pelargonium sp.) are dominated by monoterpene hydrocarbons, of which the most abundant is p‐cymene (35.8%). This oil possesses a very unusual, although very pleasant, ‘citrusy‐peppery‐spicy’ and herbaceous scent, somewhat pungent, which is rather reminiscent of thyme. Chemotaxonomic considerations about the genus Pelargonium are also discussed.