Carambola
Averrhoa carambola

Family: Oxalidaceae

What it is like

A small evergreen tree up to 6-12 m high. The trunk of the tree is short and crooked and has branches near the base. The bark is smooth and dark grey. A leaf is made up of 2 to 11 leaflets with a leaflet at the end. The leaves are darker and more shiny on the top surface. The flowers are small (8 mm long) and red and white in clusters on the small branches. The fruit are star shaped with five or six angled ridges. They are yellow and up to 16 cm long and 9 cm wide. The flesh is white. There are one or two shiny light brown seeds about 1 cm long, in the bottom of each lobe. Some carambola have short styles (female flower parts) and these types need to be cross pollinated by insects. This means two types need planting. Long style types can fertilise themselves. Fruit flavour can vary from very acid to very sweet. There are several named cultivated varieties.

There are 5 Averrhoa species. It contains 29.25 mg alpha-tocopherol (Vitamin E) per 100 g in the leaves.

Where it is found

A tropical plant. Five corners need a warm tropical climate so they are mostly seen in the coastal lowlands below about 500m altitude. They will grow up to 1200m in the equatorial tropics. Mature trees can tolerate slight frost. Five corner can grow on several different types of soil. The soil should be well drained. It will grow on alkaline soils but is better in acid soils. Plants cannot stand water-logging. It is suited to moist places but performs better in areas where there is some dry season rather than in places with heavy, constant rain. Trees are fairly wind resistant providing the winds are not cold. Trees are stressed by temperatures near 0°C as well as above 37°C. It grows in Nepal to about 300 m altitude. In XTBG Yunnan. It suits hardiness zones 10-12.

Countries/locations it is found in

Africa, Amazon, Andamans, Asia, Australia, Bangladesh, Barbados, Bhutan, Bolivia, Brazil, Burkina Faso, Cambodia, Cameroon, Central Africa, Central America, China, Colombia, Congo DR, Cook Islands, Costa Rica, Cuba, Dominican Republic, East Africa, East Timor, Ecuador, El Salvador, Fiji, Ghana, Grenada, Guam, Guyana, Haiti, Hawaii, Himalayas, India, Indochina, Indonesia (country/location of origin), Japan, Jamaica, Laos, Liberia, Malaysia (country/location of origin), Maldives, Mariana Islands, Marquesas, Mauritius, Mexico, Micronesia, Mozambique, Myanmar, Nepal, New Zealand, Nicaragua, North America, Northeastern India, Pacific, Pakistan, Palau, Papua New Guinea, Peru, Philippines, Pohnpei, Puerto Rico, Sao Tome and Principe, SE Asia, Slovenia, Solomon Islands, South America, Sri Lanka (country/location of origin), St. Vincent and Grenadines, Suriname, Taiwan, Tanzania, Thailand, Timor-Leste, Tonga, Uganda, USA, Vanuatu, Vietnam, West Africa, West Indies, Yap

How it is used for food

Fruit can be eaten raw or used for drinks. They are used in curries. They can be used for souring dishes. They are also used for jams, jellies, preserves and pickles. (They are also useful for cleaning brass.) The acid flowers are eaten in salads or made into conserves. Leaves have been eaten as a substitute for sorrel. They can be eaten with coconut milk sauce. CAUTION The fruit contain soluble oxalates.

Trees are moderately common in coastal areas of Papua New Guinea. Types vary in their sweetness. They are sold in local and global markets. It is cultivated.

Edible parts

Fruit, flowers, leaves, spice

How it is grown

Trees are grown from seed. Seeds grow easily but in fact only a small number of seeds are fertile. Well developed seeds should be chosen. Seeds are planted in a seed bed and planted out when 15-20 cm high. Because seeds are produced by cross pollination, variation is common. It is therefore better to use budding or grafting. Taking buds off good trees, or grafting twigs from them, onto 1 year old seedling roots, is the commonest method. Marcottage or air layering can also be used, although it is difficult. A spacing of 6 m x 6 m is suitable. Trees need to be grafted if sweeter kinds of fruit are to be selected. Because the seeds are covered by a fatty layer, washing them with soap improves the germination.

Seedling trees fruit after 4-5 years. They can produce 400 fruit per tree. Flowers open after 14-21 days and fruit mature after 14-15 weeks. Trees live for a long time and some fruit is produced at most times of the year. Flowers and fruit can be found on the tree at most times, although there is often 2 or 3 main flushes of flowering and fruiting. Fruiting tends to be seasonal about March to May in the southern hemisphere. The tree does not require pruning or any special care once established. Flowers are cross pollinated by bees, flies and other insects. Hand pollination does not help fruit set much. Fruit once ripe will keep for 7-20 days but can be stored longer at 12°C.

Its other names

Local names

Amrak, Ansu, Balimbieng manih, Balimbing, Balingbing, Belimbing manis, Belimbing sagi, Bikembines, Blimbing alas, Calingcing amis, Camaranga, Cambaranka, Coromandel, Dusma tahpla, Five-cornered fruit, Fivesider, Fransman birambi, Fuang, Hainijom, Kaamaranga, Kamarakh, Kamaranga, Kamrakh, Kamranga, Kamrenga, Kam rangthai, Kandasagadam, Karambola, Kardoi, Khamrak, Khe, Kordoi, Ma fueang, Ma-fueng, Mafen, Mafuang, Mak fu yang, Mak-hpung, Moyabo, Paka paka, Sisam, Sonosambal, Spo, Spu, Star Fruit, Thei-helh-hot, Torte, Wi ni Idia, Zaung-yar

Synonyms

Averrhoa pentandra Blanco;