The Star Fruit or Carambola (Averrhoa carambola) probably originated in Southeast Asia, but is now found throughout the humid tropics and subtropics. This small tree (to 15 m in height) bears rose-colored flowers that yield yellow fruits that are 8 to 12 cm long. The common name derives from the shape of the fruit in cross section. The fruit is over 90% water and is used in fruit salads, tarts, preserves, and drinks. Total sugars are around 7%, roughly half glucose and half sucrose. The acid component is mainly citric acid. The other species in the genus Averrhoa, A. bilimbi, produces a sour fruit used for pickles, jellis, and curries. (Vaughan and Geissler 1997)

Carambola is a distylous species, with individual trees having either pin (long-styled) or thrum (short-styled) flowers; each flower is compatible with flowers of the other type, but self-incompatible and incompatible with flowers of the same morph. For satisfactory fruit production, growers must plant a mixture of the two morphs, one of which acts as a pollenizer. The presence of a pollenizer is sometimes achieved by bud-grafting to a branch of the producing tree material of a different morph. (Wong et al. 1994a,b)

Ingesting Carambola can be very dangerous for individuals with renal failure (e.g., Chang et al. 2002; Signate et al. 2009).