Yuzu

Yuzu is a citrus fruit and plant in the family Rutaceae of Chinese origin. Yuzu has been cultivated mainly in East Asia, though it has also recently been grown in New Zealand, Australia, Spain, Italy, and France. It is believed to have originated in central China as an F1 hybrid of the mangshanyeju (Chinese: 莽山野橘) subspecies of mandarin orange and the ichang papeda.

Source: Wikipedia