Kaffir lime

The Kaffir lime (Citrus hystrix DC., Rutaceae), also known as kieffer lime, makrut, or magrood, is native to Indonesia but widely grown worldwide as a backyard shrub.

A very thorny bush with aromatic leaves. The oil from the rind of the rough, bumpy fruit has strong insecticidal properties. Well suited to container growing. The green lime fruits are distinguished by their bumpy exterior and their small size (approx. 4 cm wide), and the hourglass-shaped leaves (actually, the leaf and the leaf-shaped stem or phyllode) are widely used in Cambodian, Thai, and Lao Cuisine.

Citrus x hystrix leaves are also popular in Cambodia, but less so in Vietnam. Malay, Burmese and Indonesian (especially, Balinese and Javanese; see also Indonesian bay leaf) cuisines use them sporadically with chicken and fish.

Although the most common product of the Citrus x hystrix tree is its leaves (which impart a sharp lime/neroli flavour to Cambodian base paste known as "Krueng", Thai dishes such as tom yum, and to Indonesian food such as sayur assam - literally sour vegetables), the juice and rinds of the small, dark green gnarled fruit (known as jeruk obat - literally medicine citrus) are used in traditional Indonesian medicine.

As for the zest, it is widely used in creole cuisine and to impart flavor to "arranged" rums in the Réunion island and Madagascar.

The Oxford Companion to Food (ISBN 0-19-211579-0) recommends that the name kaffir lime should be avoided in favor of makrut lime because Kaffir is an offensive term in some cultures, and also has no clear reason for being attached to this plant. However, kaffir lime appears to be much more common.