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This species has a more restricted distribution in the wild than T. americana and is at its best in the Appalachians. In its typical state it is easily distinguished from T. americana by having the undersurface of the leaves clad with a close white felt of stellate hairs, which conceals the tufts of light brown hairs in the axils of the nerves.
Forms of this species exist in which the indumentum of the leaf-undersides is sparse or even almost lacking, but even these forms can be distinguished from T. americana by the closer smaller, shorter-pointed, less curved teeth. These forms have been distinguished as T. heterophylla var. michauxii (T. michauxii Nutt.), but it should be noted that the name T. michauxii Nutt. as interpreted by Sargent in the first edition of his Manual (1905) is T. americana var. vestita, and this appears to be also true of the T. michauxii of previous editions of the present work. The sparsely indumented forms of T. heterophylla are by some authorities considered to be the result of hybridisation between that species and T. americana, but are included by G. N. Jones in T. heterophylla without distinction.
No sizeable examples of T. heterophylla have been recorded but there seems to be no reason why its Appallachian forms should not succeed with us.