凸椪，又名凸顶柑、不知火、丑柑、丑橘，是日本长崎县南高来郡口之津町(现为南岛原市)的农林水产省果树考场口之津分场(现为·独立行政法人农业·食品产业技术综合研究机构·果树研究所·柑橘研究口之津据点)，1972年培植的柑橘，由清见桔橙与中野3号椪柑杂交育成。

Dekopon(デコポン) is a seedless and sweet variety of mandarin orange.

It is 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.