The leaves, flowers, peel, and juice of the fruit are used in numerous home remedies. The Rutaceae is distributed in warm and tropical areas of both hemispheres, with its centres of speciation in South Africa and Australia. There are 150 genera and some 900 species which have been divided into four or five subfamilies on characters of the carpels and structure of the fruit. Many of the species have oil glands in the leaves. Commercially, Citrus is the most important genus.
Many species are sources of essential oils of use in perfumery and medicine.
The family is especially rich in secondary metabolites of potential, if not acutal, biodynamic activity. These include ethereal oils, a variety of alkaloids, amides, occasional cyanogenic compounds, several types of coumarins, flavonoids, aromatic acids, polyphenols and tannins, lignans, tetracyclic triterpenes, limonoids, a variety of terpenes as well as saponins. The literature is vast. The 12 or 15 species of Citrus are small, often spiny shrubs and trees of the tropics and subtropics native to Asia and Malaysia. The bergamot orange is valuable in the perfume industry.