1. The name P. canadensis Moench is the correct one for the hybrid P. deltoides x P. nigra. 2. The neotype of P. canadensis Moench is preserved in the Schildbach’s xylothec under no.: 188. This xylothec is kept in the Natural History Museum at Kassel (Germany). 3. The name P. euramericana Guinier is superfluous and therefore illegitimate.