The White Poplar (Populus alba) is a species of poplar, most closely related to the aspens (Populus sect. Populus). It is native from Spain and Morocco through central Europe to central Asia, growing to heights of up to 16- 27 metres.
It has a thick trunk topped with a broad rounded crown, and the bark is smooth and greyish-white, with characteristic diamond-shaped dark marks, but blackish and fissured at the base of old trees. The annual shoots are covered with whitish-grey down, including the small buds. The leaves are 4 - 15 cm long, five-lobed, with a thick covering of white scurfy down on both sides but thicker underneath; this layer wears off the upper side but not the lower, which stays white until autumn leaf fall. Larger, deeply lobed leaves are produced on fast-growing young trees, and smaller, less deeply lobed leaves on older, slow-growing trees.
The dioecious flowers appear at the end of March and when in full bloom may be said fairly to drip catkins, so covered is every branch witht he pendulous aments, three inches long and as large as one's finger.
Cultivation
The seed capsules mature in May to July. The White Poplar also propagates by means of root suckers growing from the lateral roots, often as far as 20 - 30 metres from the trunk.
It is very attractive as an open-grown tree in water meadows, and because of its vast root system, is used also to strengthen sand dunes.
