Citrus reticulata

Evergreen tree growing 4.5 m tall by 3 m wide at a medium rate. Hardy to UK zone 9, frost tender. In leaf all year. Hermaphroditic with apomictic and insect pollination; self-fertile. Notable for attracting wildlife. Grows in medium loamy and heavy clay soils with good drainage. Tolerates mildly acidic, neutral, mildly alkaline, very acidic, and very alkaline soils. Requires full sun and prefers moist soil.

Description

A small evergreen tree up to 4-8 m tall. It spreads to 2 m across. The stem is erect, branching and thorny. The leaves are dark green, and long and narrow in shape. They are 3-4 cm long. There is only a narrow wing on the leaf stalk. It has a few or no spines. The flowers are white and star shaped. They are 2.5-4 cm across and have a scent. Fruit are almost round and the skin peels off easily. The fruit are 4-8 cm long. The flesh is red, juicy and sweet.

Edible Uses

The fruit can be eaten raw or used in puddings, cakes, confectionery, and other cooked dishes — sweet and delicious, growing up to 8cm in diameter. The dried rind has a sweet, spicy flavour and is commonly used to flavour cakes and similar baked goods.

Traditional Uses

The fruit are eaten fresh and raw. They are also used for juice, preserved in syrup, added to salads or used in sweets, cakes, and drinks. The peel is dried and is used as a condiment. The oil from the peel is used to flavour ice cream, chewing gum, and baked goods. The flower petals are eaten.

Medicinal Uses

Citrus species contain a wide range of active compounds, and research into their applications is ongoing. They are rich in vitamin C, flavonoids, acids, and volatile oils, and also contain coumarins such as bergapten, which sensitizes the skin to sunlight. Bergapten is sometimes added to tanning preparations to promote skin pigmentation, though it can cause dermatitis or allergic reactions in some people. Recent applications include use as sources of antioxidants and chemical exfoliants in specialized cosmetics. The fruit itself is antiemetic, aphrodisiac, astringent, laxative, and tonic. The flowers are stimulant. The pericarp is analgesic, antiasthmatic, anticholesterolemic, anti-inflammatory, antiscorbutic, antiseptic, antitussive, carminative, expectorant, and stomachic, and is used to treat dyspepsia, gastrointestinal distension, cough with profuse phlegm, hiccup, and vomiting. The endocarp is carminative and expectorant, used for dyspepsia, gastrointestinal distension, coughs, and profuse phlegm. The unripened green exocarp is carminative and stomachic, used in treating pain in the chest and hypochondrium, gastrointestinal distension, swelling of the liver and spleen, and cirrhosis of the liver. The seed is analgesic and carminative, used in the treatment of hernia, lumbago, mastitis, and pain or swellings of the testes.

Known Hazards

Avoid peel with dry cough or excessive red tongue or splitting blood.

Distribution

A subtropical plant. The hardiest of the citrus. It grows from sea level up to 2300 m altitude in the tropics. They do best between 800 m and 1200 m altitude. A well drained soil is needed. They also prefer a drier climate. It is drought and frost resistant. They need a temperature above 3-5 °C. It suits hardiness zones 9-11.

Where It Grows

Africa, Andes, Angola, Asia, Australia, Bangladesh, Barbados, Bolivia, Bougainville, Brazil, Burkina Faso, Cambodia, Cameroon, Central Africa, Central America, Central Asia, China, Colombia, Cook Islands, Costa Rica, Côte d'Ivoire, Cuba, Dominican Republic, East Africa, East Timor, Ecuador, Ethiopia, Europe, Fiji, Georgia, Ghana, Guam, Guinea-Bissau, Guyana, Haiti, Hawaii, Himalayas, India, Indochina, Indonesia, Ivory Coast, Japan, Kenya, Korea, Laos, Madagascar, Malawi, Malaysia, Malesia*, Mexico, Middle East, Myanmar, Nauru, Nepal, New Caledonia, Niger, Nigeria, North Africa, North America, Northeastern India, Pacific, Pakistan, Papua New Guinea, PNG, Peru, Philippines*, Rotuma, Sahel, Samoa, Sao Tome and Principe, Saudi Arabia, SE Asia, Sierra Leone, Sikkim, Solomon Islands, South Africa, Southern Africa, South America, Spain, Sri Lanka, Suriname, Taiwan, Tajikistan, Tanzania, Thailand, Timor-Leste, Tonga, Uganda, USA, Vanuatu, Vietnam, West Africa, West Indies, West Timor, Zimbabwe,

Cultivation

Growth generally ceases below 13°c and above 38°c. If there are dry periods of more than three months, then irrigation will be necessary. This species grows better in the subtropics than in the tropics. Prefers a moderately heavy loam with a generous amount of compost and sand added plus a very sunny position. Prefers a pH between 5 and 6. Tolerates a pH in the range 4.3 to 8.3. Plants are intolerant of water logging. When growing plants in pots, a compost comprising equal quantities of loam and leafmould plus a little charcoal should produce good results. Do not use manure since Citrus species dislike it. When watering pot plants it is important to neither overwater or underwater since the plant will soon complain by turning yellow and dying. Water only when the compost is almost dry, but do not allow it to become completely dry. There are many named varieties. Plants dislike root disturbance and so should be placed into their permanent positions when young. If growing them in pots, great care must be exercised when potting them on into larger containers. Most Citrus species are self-fertile, meaning they can produce fruit without needing another plant for cross-pollination, though cross-pollination can improve fruit set in some varieties. Citrus fruits are generally harvested in late autumn to early spring, depending on the specific variety and local climate. Citrus trees usually flower in the spring. Some species may have a second flowering period in late summer.

Propagation

Sow seed in containers as soon as it is ripe, after rinsing thoroughly. Stored seed should be sown in containers as soon as possible. Germination typically occurs within 2–3 weeks at 13°C. Seedlings are prone to damping off and must be watered carefully and kept well ventilated. The seed is usually polyembryonic — two or more seedlings arise from each seed, genetically identical to the parent and generally free of any virus present in the parent plant. Once seedlings are large enough to handle, prick them out into individual pots and grow on until they reach 10cm or more in height before planting out into permanent positions. Propagation is also possible from cuttings of half-ripe wood or by layering.

Other Uses

An essential oil extracted from the peel is used as a food flavouring and in perfumery and medicines, with yields of around 0.5%. An essential oil from the leaves and young twigs, known as petitgrain oil, is also produced at yields of around 0.5%. Citrus species can be incorporated into agroforestry systems as shade trees, providing dappled light for understory crops while improving biodiversity by attracting pollinators and beneficial insects, and offering a valuable cash crop. The flowers are rich in nectar and pollen, making them highly attractive to bees and other pollinators. Fruits provide food for birds and mammals, and the dense foliage offers shelter for nesting and roosting birds. Leaf litter beneath the trees creates overwintering sites for invertebrates, and the rough bark of mature trees can shelter beneficial insects. The strong citrus scent of the leaves and fruit can also act as a natural pest deterrent, confusing or repelling certain insects.

Production

Seedling trees take 4-6 years to fruit. Grafted trees fruit after 2-4 years. Fruit tend to be produced seasonally. The season is often from April to August in the Southern Hemisphere.

Other Information

Not widely grown in Papua New Guinea but more are being planted. It is a cultivated food plant.

Notes

There are 20 Citrus species. Several hybrids have been formed.

Nutrition

Synonyms

Also Known As

Chieh, Chu, Clementine, Cur. oranje, Hondra, Jamanarang, Jeruk keprak, Jeruk keprok, Jiaogan, Ju, Kak0sawk, Kamala, Kamla lebu, Komla, Kyul, Lawidwi, Lein-hmaw, Leing maw thee, Mandarina, Mandarine, Mandarini, Mangada, Mikan, Moli madarini, Monarikisi, Nagpur suntra, Naran, Narangi, Nartjie, Santara, Satsuma, Shalawi, Soco madarini, Som khiew wan, Suntala, Tangerina, Tangerine, Te mantarin, Tunmapa

References (86)

• AAK, 1994, Jeruk, Penerbit Kanisius, Jogyakarta. p 191
• Abbiw, D.K., 1990, Useful Plants of Ghana. West African uses of wild and cultivated plants. Intermediate Technology Publications and the Royal Botanic Gardens, Kew. p 42
• Ambasta, S.P. (Ed.), 2000, The Useful Plants of India. CSIR India. p 129
• Anderson, E. F., 1993, Plants and people of the Golden Triangle. Dioscorides Press. p 206
• Arora, R. K., 2014, Diversity in Underutilized Plant Species - An Asia-Pacific Perspective. Bioversity International. p 64 (Also as Citrus tankan)

More from Rutaceae

Zanthoxylum heterophyllum

Zanthoxylum khasianum

Sumer-chheng, Soh-umiuw

Zanthoxylum lemairei

Zanthoxylum limonella

Indian pepper

🌱

Zanthoxylum macrophyllum var. preusii

Zanthoxylum martinicense

Martinique prickly ash