Tilia is a genus of about 30 species of trees or bushes, native throughout most of the temperate Northern Hemisphere. The tree is known as linden for the European species, and basswood for North American species. In Britain and Ireland they are commonly called lime trees, although they are not related to the citrus lime.

Lime trees are citrus plants that originate in southern Asia. They like sun. Limes usually have smooth green skin. They are tart, bitter, sour and acidic to taste and are popular in many cuisines to flavor foods and drinks.