London Planetree
Platanus acerifolia, the London plane, London planetree, or hybrid plane, is a tree in the genus Platanus. It is often known by the synonym Platanus × hispanica. It is usually thought to be a hybrid of Platanus orientalis (oriental plane) and Platanus occidentalis (American sycamore). Some authorities think that it may be a cultivar of P. orientalis.
The London plane is a large deciduous tree growing 20–30 m (66–98 ft), exceptionally over 40 m (131 ft) tall, with a trunk up to 3 m (10 ft) or more in circumference. The bark is usually pale grey-green, smooth and exfoliating, or buff-brown and not exfoliating. The leaves are thick and stiff-textured, broad, palmately lobed, superficially maple-like, the leaf blade 10–20 cm (4–8 in) long and 12–25 cm (5–10 in) broad, with a petiole 3–10 cm (1–4 in) long. The young leaves in spring are coated with minute, fine, stiff hairs at first, but these wear off and by late summer the leaves are hairless or nearly so. The flowers are borne in one to three (most often two) dense spherical inflorescences on a pendulous stem, with male and female flowers on separate stems. The fruit matures in about 6 months, to 2–3 cm diameter, and comprises a dense spherical cluster of achenes with numerous stiff hairs which aid wind dispersal; the cluster breaks up slowly over the winter to release the numerous 2–3 mm seeds. The London Plane is one of the most efficient trees in removing small particulate pollutants in urban areas.
It shares many visual similarities with Platanus occidentalis (American sycamore), from which it is derived; however, the two species are relatively easy to distinguish, considering the London plane is almost exclusively planted in urban habitats, while P. occidentalis is most commonly found growing in lowlands and alluvial soils along streams.
The London plane is very tolerant of atmospheric pollution and root compaction, and for this reason it is a popular urban roadside tree. The tree is fairly wind-resistant.
Info: Wikipedia | Creative Commons
