Platanus x hispanica

Platanus x hispanica, an imposing deciduous tree, is none other than the common plane tree or London plane tree.  It is recognizable by its wide canopy, tall stature, large palmate bright green leaves, and its trunk covered with bark that peels in a unique way in large flakes, revealing patches of light yellow and white. Fast-growing, hardy, happy in most soils and well-adapted to summer drought, the plane tree is a tree without demanding requirements that is universally appreciated for the shade it provides in summer.

The common plane tree is the result of the cross-breeding of the American sycamore (Platanus occidentalis), native to North America, and the Oriental plane tree (Platanus orientalis), native to southeastern Europe and western Asia. This cross-breeding took place in Spain (hence its name Platanus x hispanica), but also in England around 1650. Almost sterile, this hybrid produces very few viable seeds and mainly reproduces through cuttings. Its lifespan is counted in hundreds of years.

The common plane tree generally reaches a height of 30 m (98ft) with a spread of 20 m (66ft), depending on the growing conditions.  It develops a wide trunk, with a variable appearance, which can be slender or stocky. The crown is wide and airy, supported by sturdy branches that are not very upright. The characteristic bark, cracks into large flakes, revealing light areas. The plane tree bears large, tough and glossy deciduous leaves, of a medium green colour, which can reach 20 cm (8in) wide, divided into 3 or 7 pointed and slightly toothed lobes. They turn yellow then brown in autumn before falling. They decompose very slowly, which often requires gardeners to spend long hours collecting them. In spring, the young shoots are covered with light brown hairs that can be irritating to the eyes, throat, and respiratory tract. The unusual flowers occur in May: the flowers are gathered in 'pompoms' hanging from a long stalk. On plane trees, female and male flowers are separate but present on the same tree. After wind pollination, the female flowers produce tiny fruits called achenes, which are surrounded by a down. These curious pompom-like infructescences persist on the branches long after the leaves have fallen.

The common plane tree adapts wonderfully to all types of soils, including polluted urban areas or very dry countryside, and it tolerates pruning if done well.  All these qualities certainly explain its success as a park tree, shade tree, or avenue tree. Unfortunately, this giant that was thought to be indestructible is attacked by several exotic pests and diseases: two deadly fungi responsible for the coloured canker disease and black spot, as well as the plane tree moth, a sucking insect considered a likely vector of diseases. As is often the case, these epidemics are favoured by overcrowding as well as mass pruning carried out without particular precautions. The plane tree remains a very interesting plant , hosting a whole little-known fauna under and on its unusual and characteristic bark.