The Pelargonium cultivar grown on Réunion for the production of rose-scented geranium oil is locally known as the cv. Rosé. The origin of the cv. Rosé is demonstrated by comparing its morphology, chromosome number and essential oil with those of putative ancestral species. It is concluded that P. capitatum (L.) L’Hérit. and P. radens H.E. Moore can be considered as the parent species. A comparison of the characters of the cv. Rosé and those of artificial hybrids between P. capitatum and P. radens, confirmed the assumption
