Dekopon

Dekopon (デコポン?) is a seedless and very sweet citrus fruit, a hybrid between Kiyomi and ponkan (Nakano no.3), developed in Japan in 1972. Originally a brand name, Dekopon has become a genericized trademark and it is used to refer to all brands of the fruit; the generic name is shiranuhi or shiranui (不知火?). Dekopon is distinctive due to its sweet taste, large size and the large protruding bump on the top of the fruit.