Some 16 species of small, evergreen trees and shrubs comprise this genus, native to SE Asia and E Pacific islands. Most citruses have been cultivated for so long that their origins are obscure. The species are very closely related, with numerous hybrids and cultivars. Citruses were unknown in Europe in Classical times, through C. aurantium and C. bergamia were first mentioned in Chinese medicine in the first century CE. The first citrus to arrive in Europe was the bitter orange, C. aurantium, probably brought by the Portuguese from the East Indies. It was followed by C. limon, probably from China, somewhere between tthe 11th and 13th centuries. Medicinal uses of citruses are complex. Various parts of the tree are used, and also various parts of the fruit at different stages of ripeness. Commonly, the leaves, fruits, juice and bark are used, while in China several quite different drugs are prepared from the fruits alone - one of the most valuable being the peel of C. reticulata, which becomes more potent with age. The related Poncirus trifoliata (hardy orange, Japanese bitter orange) is used in identical ways to C. aurantium. Citruses are high in vitamin C, flavonoids, acids, and volatile oils. They also contain coumarins, such as bergapten, which sensitize the skin to sunlight. Bergapten is sometimes added to tanning preparations and may cause dermatitis or allergic responses. The most recent uses of citruses are anti-oxidants and chemical exfoliants in cosmetics.

Small spiny tree or shrub with narrowly ovate, light green leaves, 5-10cm (2-4in) long. Pale purple-budded, fragrant white flowers 4-5cm (1½-2in) across, appear in spring and summer, followed by ovoid yellow fruits, 7-15cm (3-6in) long, containing very sour pulp.

Common Name:
Botanical Name:
Citrus limon
Native Location:
Unknown (probably China) introduced to Mediterranean CE1000-1200
Well-drained, neutral to slightly acid soil in sun, with ample moisture during the growing season. Scale insects, mealybugs, and tortrix moth caterpillars may affect plants under cover. Citruses do not transplant well.
By seed sown when ripe or in spring at 16° C (61°F); by semi-ripe cuttings in summer. Cultivars do not come true from seed.
Flowers (C. aurantium, C. bergamia) are picked when first open and distilled for oil. Leaves (C. aurantiifolia, C. hystrix) are picked as required for flavoring and infusions. Oil is distilled from foliage, unripe fruits (C. aurantium) and ripe fruits (C. bergamia). Fruits are picked when unripe or ripe for culinary use, candying, or oil distillation, and either unripe or ripe (C. aurantium, C. reticulata) for use in Chinese medicine.
Meyer syn. C. x meyeri
Is compact, with prolific blossoms and medium-sized, rounded fruits. Discovered in China in early 1900s.

Has yellow-edged leaves and immature fruits striped yellow and green.
2-7m (6-22ft)
1.5-3m (5-10ft)
Min. 5°C (41°F). Sometimes withstands short periods of 0°C (32°F)
Almost everyone knows that citrus fruits are rich in vitamin C and provide delicious, thirst-quenching drinks. Many others are familiar with the fragrant citrus oils used in aromatherapy and bathwaters. Few people, however, realize that several of the citrus species have been used medicinally for centuries in Asian medicine, and are used increasingly in the West as well (where they were not introduced until the twelfth century). Lemon is one of the best examples of medicinally used citrus fruits.
Parts Used:
Fruits, juice, peel, oil
A bitter, aromatic, cooling herb that has diuretic and anti-inflammatory effects, and improves peripheral circulation.
Medicinal Uses:
Internally for varicose veins, hemorrhoids, kidney stones, feverish minor illnesses, and bronchial congestion. Juice taken in hot water (with addition of honey, garlic, cinnamon, etc.) for colds and flu. Externally for eczema, chilblains, sunburn, and poisonous stings, and as gargle for sore throats. Essential oil is used externally to treat mouth ulcers.
Lemon has anti-inflammatory, astringent, cardiotonic, cooling, diuretic, pain-relieving, stimulant, and wound-healing properties. It is taken internally to strengthen and stimulate the circulatory system and to treat bronchitis, colds, congestion, coughs, fevers, heart palpitations, hemorrhoids, kidney stones, poor circulation and varicose veins. Many Europeans also drink lemon juice in water as a daily heart tonic.
Culinary Uses:
Fruits and grated peel (zest) are ingredients in lemonade and other soft drinks, ice cream, sorbets, desserts, marmalades, salad dressings, and marinades. Juice is used as a coagulant in cheese-making, and to set jams. Sliced lemons are a garnish for drinks, fish, and seafood dishes. Preserved lemons feature in Moroccan cuisine. Lemons are pressed with olives to produce lemon-olive oil, known as limonato.
Economic Uses:
Inner peel and pulp are a souce of pectin, used to set sugarless jams and jellies. Essention oil, known as cedro oil, is used as a flavoring in the food industry. Oil is also used to scent soaps, detergents, and perfumery. Peel is dried for potpourris.
Encyclopedia of Herbs by Deni Brown Copyright © 1995, 2001 Dorling Kindersley Limited Pp 171-173
The Modern Herbal Primer by Nancy Burke Copyright©2000 Yankee Publishing, Inc. pp 137-138.