What is the name of the citrus fruit in the picture?

Kaffir lime, Thai lime or makrut lime, is a citrus fruit native to tropical Southeast Asia.

It is a thorny shrub or small tree, 2 to 11 metres (6 to 35 ft) tall, with aromatic and distinctively shaped "double" leaves. These hourglass-shaped leaves comprise the leaf blade plus a flattened, leaf-like stalk.

The fruit is rough and green and ripens to yellow; it is distinguished by its bumpy exterior and small size, approximately 4 cm (2 in) wide. The fruits have thick skins (pericarps) and taste very acidic and slightly bitter.Flowers can have four to five petals that are white in color and are fragrant.

Its fruit and leaves are used in Southeast Asian cuisine, and its essential oil is used in perfumery. Its rind and crushed leaves emit an intense citrus fragrance.