yuzu a distinctive citrus fruit which was formerly recognized as a species, Citrus junos, but is now regarded as a hybrid, possibly between C. ichangensis and C. reticulata. It is one of the most cold resistant of the citrus fruits and grows wild in Tibet and the interior of China, where there is some cultivation of it. It is more commonly grown in Japan, where the acid fruit is a popular ingredient.
The fruit is the size of a mandarin orange, bright yellow when ripe, with a thick uneven skin and paler flesh containing many pips. It smells like a lime, and has a very sharp taste.