Tilia is a genus of about 30 species of trees native throughout most of the temperate Northern Hemisphere. They are generally called lime in Britain and linden or basswood in North America. The greatest species diversity is found in Asia, and the genus also occurs in Europe and eastern North America, but not western North America. Under the Cronquist classification system, this genus was placed in the family Tiliaceae, but genetic research by the Angiosperm Phylogeny Group has resulted in the incorporation of this family into the Malvaceae.