The number of species and subspecies that comprise North American sugar maples has remained in dispute since their first characterization over 100 years ago. The distinction between Acer nigrum (black maples) and Acer saccharum (sugar maples) in particular has been controversial. Despite readily distinguished morphologies and different adaptive advantages, these trees hybridize readily and their ranges extensively overlap. Extensive RAPD-PCR based analyses of A. nigrum and A. saccharum trees collected from throughout their range reveal that they are genetically distinguishable only on a geographical basis and not by their morphologies. The extent to which locally collected, indigenous trees displaying the characteristic A. nigrum and A. saccharum morphologies are genetically indistinct, seriously undermines the basis for assigning distinguishing species names to these trees. The distinctive characteristics of these trees may be affected by a relatively small set of genes or may even constitute inducible responses on the part of trees to their local environments.