and the eastern cottonwood (populus deltoides), and the non-native white poplar (populus alba) and Lombardy poplar (populus nigra). All told, there are over 40 species of populus found in North ...

To study post-mating reproductive barriers creating segregation distortions, we developed a controlled backcross of an F 1 natural poplar hybrid (Populus tremula × alba) with a pure P.