Bitter/Seville orange (Citrus aurantium)

It is a type of tree that grows in the Mediterranean region and in California, Florida, or other parts of the world. Extracts of the tree's flowers, leaves, and dried fruit and peel are used in herbal medicine. Traditionally uses include digestive problems, epilepsy, fatigue, insomnia, infections, respiratory problems, skin problems, and many other uses. As a flavoring, essence of bitter orange is found in the drinks Triple Sec and Cointreau.

The bitter orange tree is one of the most useful for perfumery - every part yields an interesting raw material. The flowers provide orange blossom absolute and neroli oil, the leaves and tender buds give petit grain, while the fruit peel contains the wonderfully rich and complex bitter orange oil.

Neroli and orange blossom oils are among the most important ingredients in perfumery, decorating the top accords of chypre compositions, lending a fresh touch to floral bouquets and forming the bodies of classical colognes.

In traditional medicine systems, bitter orange supplements and extracts are used to treat digestive problems such as nausea, constipation and indigestion. You’ll also see bitter orange supplements marketed as treatments for heartburn, congestion, weight loss and a variety of skin conditions (usually fungal problems). Bitter orange has a complex chemical makeup. Of particular value is the oil that is extracted from the peel of bitter orange. This oil gives bitter orange a strong odor and flavor and is used as a remedy for a variety of health problems. The peel contains flavones, the alkaloids synephrine, octopamine, and N-methyltyramine, and carotenoids. Bitter orange is a common ingredient in weight-loss supplements but poses risks because of its stimulant-like effects. Only the peel of bitter orange has proven medicinal value, mainly for digestive problems and a few other health concerns.