Dekopon is a seedless and sweet variety of mandarin orange.
Dekopons are very large for mandarins— they can weight up to a pound each. They also have a characteristic large bump on one end, and thick, bumpy skin. Despite this, they are easy to peel like many mandarins, and have very thin membranes covering the firm, seedless flesh. The flavor is similar to an intense orange, but sweeter, since all dekopons must have citric acid levels below 1.0 percent. It is so sweet that is has been compared to eating candy. In fact, many people claim that the Dekopon is the most delicious citrus available today.
The Dekopon orange is actually a large variety of Japanese mandarin, not a true orange; it is a cross between a Kiyomi tangor and a Ponkan mandarin orange. In Japan, Dekopons are also known as shiranuhi, and hallabong in Korea, while in the United States they are usually referred to as Sumos. The name Dekopon comes from the Japanese word "deko," which means "bump," and "pon," which refers to its Ponkan madarin parent.