Populus × canescens, the grey poplar, is a hybrid between Populus alba (white poplar) and P. tremula (common aspen).

It is intermediate between its parents, with a thin grey downy coating on the leaves, which are much less deeply lobed than the leaves of P. alba.

It is a very vigorous tree with marked hybrid vigour, reaching 40 metres (130 feet) tall and with a trunk diameter over 1.5 m (5 ft) – much larger than either of its parents.

[3] In 1804, James Edward Smith raised it to a full species, P. canescens.

[4] Later authors sometimes noted the possibility that the grey poplar was a hybrid.