Populus alba (silver-leaf poplar).
Abstract P. alba, the white or silver-leaved poplar, is widely grown as an ornamental for its silvery foliage. It is a fast-growing tree utilized in afforestation and reforestation due to its resistance to drought, salt and wood borers. It is not as important commercially as poplar species of sect. Aigeiros, but its adaptation to warm conditions allows it to be cultivated in Mediterranean regions and in Central Asia. P. alba is widely used in interspecific breeding programmes to introduce valuable traits, such as high rooting ability of stem cuttings, into economically more valuable species, particularly P. tremula of sect. Populus. P. alba hybridizes readily with this closely related species, the resulting hybrid, known as grey poplar (Populus x canescens), being intermediate morphologically between its parents, with a thin, grey, downy coating on the leaves, which are also much less deeply lobed than in white poplar. It exhibits marked hybrid vigour, with trees displaying vigorous growth and reaching 40 m in height and over 1.5 m in trunk diameter, much larger than either of its parents.P. alba is suitable for propagation by tissue culture and is used as a subject for Agrobacterium-mediated genetic transformation.