Populus × canescens, the grey poplar, is a hybrid between Populus alba (white poplar) and Populus tremula (common aspen). It is intermediate between its parents, with a thin grey downy coating on the leaves, which are also much less deeply lobed than the leaves of P. albus. It is a very vigorous tree with marked hybrid vigour, reaching 40 m tall and with a trunk diameter over 1.5 m – much larger than either of its parents. Most trees in cultivation are male, but female trees occur naturally and some of these are also propagated.