Carambola, Star Fruit

Averrhoa carambola

Physical Characteristics

Averrhoa carambola is an evergreen Tree growing to 8 m (26ft) by 8 m (26ft) at a slow rate. See above for USDA hardiness. It is hardy to UK zone 10 and is frost tender. The flowers are pollinated by Bees, Flies, Butterflies. The plant is not self-fertile. Suitable for: light (sandy) and medium (loamy) soils and prefers well-drained soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils and can grow in very acid and very alkaline soils. It cannot grow in the shade. It prefers moist soil and can tolerate drought. The plant can tolerates strong winds but not maritime exposure.

Distribution

E. Asia - Malaysia.

Habitats

Edible Uses

Edible Parts: Flowers Fruit Leaves Edible Uses: Condiment Edible portion: Fruit, Flowers, Leaves. Fruit - raw. The fruit is crisp and juicy with a waxy yellow skin when ripe[ 296 ]. The best forms are delicious on their own, they also go very well in fruit salads, juiced and mixed with other fruits etc[ 296 ]. The fruit flavour is enhanced by peeling off the 'wing' edges, which removes most of the oxalic acid[ 303 ]. A quince-like fragrance[ 200 ]. Plants can produce fruit all year round[ 296 ]. Fruit quality is variable, though they are normally juicy. Sour forms, and slightly immature fruits, are pickled or made into a relish[ 301 ]. The orange-yellow fruit is a large, indehiscent berry, 5-8 cm long with a characteristic shape in cross-section resembling a 5-pointed star[ 303 ]. The fruit is up to 12.5cm x 6cm[ 200 ]. Flowers - raw[ 301 ]. An acid flavour, they are added to salads[ 301 ]. They can also be made into conserves[ 301 ]. Leaves - raw or cooked[ 301 ]. An acid flavour, they are used as a sorrel substitute[ 301 ].

Medicinal Uses

Abortifacient Antiasthmatic Antirheumatic Antitussive Emmenagogue Febrifuge Galactogogue Hypotensive Skin The fruit can be a laxative on account of the oxalic acid it contains[ 303 ]. It is also used in traditional medicine for skin disorders and fevers[ 303 , 348 ]. It is valued by Chinese communities as a remedy for high blood pressure, whilst it is also said to reduce blood sugar levels and so is of help to diabetics[ 307 ]. The flowers are used to relieve coughs[ 307 ]. The leaves are used to treat rheumatism[ 307 ]. The seed is emmenagogue, galactagogue and abortifacient[ 272 ]. The powdered seed is a good anodyne for treating asthma, colic and jaundice[ 272 ].

Known Hazards

The fruit contain soluble oxalates.