The fruit is about 5 to 15 centimetres (2 to 6 inches) in length and is
an oval shape. It usually has five prominent longitudinal ridges, but in
rare instances it can have as few as four or as many as eight. In cross
section, it resembles a star. The skin is thin, smooth, and waxy and
turns a light to dark yellow when ripe. The flesh is translucent and
light yellow to yellow in color. Each fruit can have 10 to 12 flat light
brown seeds about 6 to 13 mm (0.25 to 0.5 in) in width and enclosed in
gelatinous aril. Once removed from the fruit, they lose viability within
a few days..Like the closely related bilimbi, there are two main types of carambola:
the small sour (or tart) type and the larger sweet type. The sour
varieties have a higher oxalic acid content than the sweet type. A
number of cultivars have been developed in recent years. The most common
cultivars grown commercially include the sweet types "Arkin" (Florida),
"Dah Pon" (Taiwan), "Ma fueng" (Thailand), "Maha" (Malaysia), and
"Demak" (Indonesia) and the sour types "Golden Star", "Newcomb", "Star
King", and "Thayer" (all from Florida). Some of the sour varieties like
"Golden Star" can become sweet if allowed to ripen.