Citronella is a grass that mainly grows in some Asian countries and some islands of the South Pacific. It has a rich, crisp lemony aroma and thus bears the name citronella. The essential oil of citronella is extracted from two varieties of citronella. The first one is the Ceylon variety, whose scientific name is Cymbopogon nardus and the second one is Java variety, called Cymbopogon winterianus in botanical terminology. In both cases, the essential oil is extracted by steam distillation of the fresh plant.