Plan Tree, London

Plan Tree, London — The London Plane or Hybrid Plane (Platanus × hispanica, synonyms Platanus × acerifolia and Platanus × hybrida) is a tree in the genus Platanus. It is usually thought to be a hybrid of the Oriental Plane, P. orientalis, with the American Plane (American sycamore), P. occidentalis. Some authorities think that it may be a cultivar of P. orientalis, but there is little evidence for this.

It is a large deciduous tree growing to 20-35 m (exceptionally over 40 m) tall, with a trunk up to 3 m or more in diameter. 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 long and 12-25 cm broad, with a petiole 3-10 cm 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.

It is very tolerant of atmospheric pollution and root compaction, and for this reason it is a popular urban roadside tree. It is now extensively cultivated in most temperate latitudes as an ornamental and parkland tree, and is a commonly planted tree in cities throughout the temperate regions of the world, not just London but Buenos Aires, New York City, Paris, Madrid, Melbourne,Shanghai and many others. It has a greater degree of winter cold tolerance than the Oriental Plane, and is less susceptible to anthracnose disease than the American Plane. The seeds are used as a food source by some finches and squirrels.