Silver poplar

Description

Populus alba, commonly called silver poplar, silverleaf poplar, or white poplar, is a species of poplar, most closely related to the aspens (Populus sect. Populus). It is native to Morocco and then Portugal through central Europe (north to Germany and Poland) to central Asia. It grows in moist sites, often by watersides, in regions with hot summers and cold to mild winters. It is a medium-sized deciduous tree, growing to heights of up to 15–30 m, with a trunk up to 2 m in diameter and a broad, rounded crown. The bark is smooth and greenish-white to greyish-white with characteristic diamond-shaped dark marks on young trees, becoming blackish and fissured at the base of old trees. The young 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 8 cm long, produced in early spring; they are dioecious, with male and female catkins on separate trees; the male catkins are grey with conspicuous dark red stamens, the female catkins are greyish-green. The female catkins lengthen to 8–10 cm after pollination, with several green seed capsules, maturing in late spring to early summer. It also propagates by means of root suckers growing from the lateral roots, often as far as 20–30 m (65–100 ft) from the trunk, to form extensive clonal colonies. White poplar hybridizes with the closely related common aspen Populus tremula; the resulting hybrid, known as grey poplar (Populus × canescens), is intermediate between its parents, with a thin, grey, downy coating on the leaves, which are also much less deeply lobed than white poplar leaves. It is a very vigorous tree with marked hybrid vigour, reaching 40 m (130 ft) tall and a trunk diameter over 1.5 m (4 ft 11 in), much larger than either of its parents. Most grey poplars in cultivation are male, but female trees occur naturally and some of these are also propagated. The wood is soft but close-grained and easy to carve, shrinking very little during seasoning. It has been used for sculpture from Europe to China and the US. The Penitent Magdalene by Donatello is one 15th-century example. It was the most commonly used wood for panel paintings in Italy throughout the Middle Ages and Renaissance, until mostly replaced as a matrix by canvas from 1500 onwards. Most earlier Italian Renaissance paintings are painted on poplar panels, the Mona Lisa being but one example.