1. Taxonomy

Current name: Averrhoa carambola
Authority: L.
Family: Averrhoaceae

2. Synonym(s)
Averrhoa acutangula Stokes

3. Botanical description

Matured starfruit/carambola tree is a slow-growing, short-trunk evergreen tree with a much-branched, bushy canopy that is broad and rounded (see Figure 1).

Carambola tree			Mature trees are multi-stemmed 3-5 m high or rarely 10 m high, attaining 15 cm diameter at the base; bark light brown, smooth or finely fissured. Container grown plants are equally attractive and have the additional advantage of being movable. In a spot to their liking, starfruit trees make handsome ornamentals. It is a tropical and subtropical tree, it can tolerate freezing temperature (-2 degree Celsius) for short periods and sustain little damage. Its deciduous leaves, spirally arranged, are alternate, imparipinnate, 15 - 20 cm long, with 5 to 11 nearly opposite leaflets, ovate or ovate-oblong, 3.8 - 9 cm long; soft, medium-green, and smooth on the upper surface, finely hairy and whitish on the underside. The leaves have the peculiarity of being sensitive to touch in the same way as certain Mimosa species; sensitive to light and more or less inclined to fold together at night. Inflorescence (see Figure 2) in panicles 2 - 5 cm long borne in clusters in axils of leaves on young branches, or on older branches without leaves.

Inflorescence of carambola			Flowers are pentamerous, fragrant, pink to lavender flowers are 9-10 mm in diameter, perfect. There are several flushes of bloom throughout the year with a calyx of 5 pink sepals surrounding the purple corolla; androecium contains 5 fertile stamens and 5 staminoids; gynoecium bears 5 slender united styles. Fruit is a large ovate to ellipsoid indehiscent berry, 6 to 13 cm in length, with 5 (rarely 4 or 6) prominent longitudinal ribs, 5-8 cm long; with a characteristic shape in cross-section resembling a 5-pointed star; yellowish-green, becoming orange-yellow when ripe.

			The skin is thin, light to dark yellow and smooth with a waxy cuticle. The flesh is light yellow to yellow, translucent, crisp and very juicy, without fiber. The fruit has a more or less oxalic acid odor and the flavor ranges from very sour to mildly sweet. The so-called sweet types rarely have more than 4% sugar. Each cell of the fruit contains 5 arillate seeds. There may be up to 12 flat, thin brown seeds .63 - 1.25 cm long or none at all. Seeds lose viability in a few days after removal from fruit. They probably originated in Sri Lanka and the Moluccas, and have been cultivated in Southeast Asia and Malaysia for several centuries. They are also grown throughout the Caribbean, Central and South America. It is commonly grown in the provinces of Fukien, Kuangtung and Kuangsi in southern China, in Taiwan and India. It is rather popular in the Philippines and Queensland, Australia, and moderately so in some of the South Pacific islands, particularly Tahiti, New Caledonia and Netherlands New Guinea, and in Guam and Hawaii.

There are two fruit types found in markets, one very sour and the other slightly sweet. It is almost impossible to tell the sweet and tart varieties apart, but in general the sweet varieties have thicker, fleshier ribs; some also report that the more yellow fruits, the sweeter. There are several white varieties, all of which are sweet.

Commercial production occurs in Taiwan, Malaysia, southern China, the Philippines, Australia, USA (Florida, Hawaii), Brazil, Suriname and Guyana. Production and consumption appears on the rise throughout the world and will most likely increase as selection and breeding for superior tasting cultivars with improved handling characteristics and storage conditions are found.

The generic name is after Averrhoes (1126-98), the widely known Arab Philosopher. The specific name, 'Averrhoa carambola', is said to have come from Malabar and was adopted early by the Portuguese.