Star fruit, also known as carambola, is a star-shaped tropical fruit with sweet and sour flavor. Carambola is native to the Malayan peninsula and cultivated in. Star fruit is a sweet and sour fruit that is shaped like a star. For most people though, star fruit is a healthy and tasty addition to the diet. Star fruit has a sweet, slightly tangy flavor. The fruit contains a neurotoxin that healthy kidneys can filter out, but damaged kidneys are unable to do so. Go to a.