Description

Evergreen tree growing to 30 ft (10 m). Has leathery, dark green leaves, delicately perfumed white flowers, and orange fruit.

Habitat & Cultivation

Native to tropical Asia, this tree is now grown throughout the tropics and subtropics. Orchards of bitter orange are found along the Mediterranean coast, especially in Spain.

Parts Used

Fruit, peel, leaves, flowers, seeds, essential oil.

Constituents

Bitter orange peel contains a volatile oil with limonene (around 90%), flavonoids, coumarins, triterpenes, vitamin C, carotene, and pectin. The flavonoids are anti-inflammatory, antibacterial, and antifungal. The composition of the volatile oils in the leaves, flowers and peel varies significantly. Linalyl acetate (50%) is the main constituent in oil from the leaves (petitgrain) and linalool (35%) in oil from the flowers (neroli). The unripe fruit of the bitter orange contains cirantin, which reportedly is contraceptive.

History & Folklore

The bitter orange has provided food and medicine for thousands of years. It yields neroli oil from its flowers, and the oil known as petitgrain from its leaves and young shoots. Both distillates are used extensively in perfumery. Orange flower water is a by-product of distillation and is used in perfumery and to flavor candies and cookies, as well as being used medicinally.

Medicinal Actions & Uses

The strongly acidic fruit of the bitter orange stimulates digestion and relieves flatulence. An infusion of the fruit is thought to soothe headaches, calm palpitations, and lower fevers. The juice helps the body eliminate waste products and, being rich in vitamin C, helps the immune system ward off infection. If taken to excess, however, its acid content can exacerbate arthritis.

In Chinese herbal medicine, the unripe fruit, known as zhi shi, is thought to “regulate the qi,” helping to relieve flatulence and abdominal bloating, and to open the bowels. The essential oils of bitter orange, especially neroli, are sedative. In Western medicine, these oils are used to reduce heart rate and palpitations, to encourage sleep, and to soothe the digestive tract. Diluted neroli is applied as a relaxing massage oil. The distilled flower water is antispasmodic and sedative.

Related Species

The lime (C. aurantiifolia) and lemon (C. limon) have nutritional properties that are similar to those of bitter orange. See also bergamot (C. bergamia).

Caution

Do not take the essential oils internally except under professional supervision.