Bitter Orange, Sour orange, Bergamot orange

Citrus aurantium

Physical Characteristics

Citrus aurantium is an evergreen Tree growing to 9 m (29ft) by 6 m (19ft) at a medium rate. See above for USDA hardiness. It is hardy to UK zone 9 and is frost tender. It is in leaf all year, in flower from April to June. The species is hermaphrodite (has both male and female organs) and is pollinated by Apomictic (reproduce by seeds formed without sexual fusion), insects. The plant is self-fertile. It is noted for attracting wildlife. Suitable for: medium (loamy) and heavy (clay) soils and prefers well-drained soil. Suitable pH: mildly acid and neutral soils and can grow in very alkaline soils. It cannot grow in the shade. It prefers moist soil.

Distribution

Tropical Asia?

Habitats

Woodland Garden Sunny Edge; Hedge; South Wall. By. West Wall. By.

Edible Uses

Edible Parts: Fruit Oil Oil Edible Uses: Condiment Oil Oil Fruit - raw or cooked[1, 3]. Very bitter[46]. It is used in making marmalade and other preserves[3, 46, 61, 183]. The fruit is about 5 - 7cm in diameter[200]. The rind of the fruit is often used as a flavouring in cakes etc[1, 4]. Used in 'bouquet garni'[183]. An oil obtained from the seeds contains linolenic acid and is becoming more widely used as a food because of its ability to reduce levels of cholesterol in the blood[7]. The flowers are used for scenting tea[183]. An essential oil from the dried peel of immature fruits is used as a food flavouring[183].

Medicinal Uses

Antianxiety Antibacterial Antiemetic Antifungal Antispasmodic Antitussive Appetizer Aromatherapy Carminative Contraceptive Diaphoretic Digestive Miscellany Sedative Stimulant Stomachic Tonic Vitamin C Citrus species contain a wide range of active ingredients and research is still underway in finding uses for them. They are rich in vitamin C, flavonoids, acids and volatile oils. They also contain coumarins such as bergapten which sensitizes the skin to sunlight. Bergapten is sometimes added to tanning preparations since it promotes pigmentation in the skin, though it can cause dermatitis or allergic responses in some people[238]. Some of the plants more recent applications are as sources of anti-oxidants and chemical exfoliants in specialized cosmetics[238]. The plants also contain umbelliferone, which is antifungal, as well as essential oils that are antifungal and antibacterial[218]. They also contain the pyrone citrantin, which shows antifertility activity and was once used as a component of contraceptives[218]. Both the leaves and the flowers are antispasmodic, digestive and sedative[7, 9]. An infusion is used in the treatment of stomach problems, sluggish digestion etc[9]. The fruit is antiemetic, antitussive, carminative, diaphoretic, digestive and expectorant[218].The immature fruit can be used (called Zhi Shi in China) or the mature fruit with seeds and endocarp removed (called Zhi Ke). The immature fruit has a stronger action. They are used in the treatment of dyspepsia, constipation, abdominal distension, stuffy sensation in the chest, prolapse of the uterus, rectum and stomach[176]. The fruit peel is bitter, digestive and stomachic[7]. The seed and the pericarp are used in the treatment of anorexia, chest pains, colds, coughs etc[218]. The essential oil is used in aromatherapy. Its keyword is 'Radiance'[210]. It is used in treating depression, tension and skin problems[238].

Known Hazards

None known