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