Tilia heterophylla

Tilia heterophylla, the white basswood, is a species of Tilia native to mesic forests in eastern North America from central New York south to northernmost Florida and west to Missouri; it is most common in the Appalachian Mountains.

Its primary distinguishing characteristic from other North American Tilia species is the presence of dense felt (tomentum) of white hairs on the underside of the leaves. It has often been considered to be a variety of Tilia americana, as Tilia americana var. heterophylla, though some others place it as a species in a separate section of the genus, more related to other European and Asian Tilia species with white tomentum on the undersides of the leaves, such as Tilia tomentosa. The problem of its species status and placement in the genus is complicated by extensive natural hybridization with Tilia americana.