The plum is the fruit of the plum tree, which is native to the Caucasus. It was introduced to France at the time of the crusades by the botanist Pierre Belon. From the 16th century, different varieties of plum were developed, in particular the "Reine Claude" which was named after the wife of the French king Francis I. In the medicinal field it is used for its diuretic and stimulating virtues. In cosmetics it is used for its smoothing properties and tightening effect, which come from its high content of proteins.