The London plane is a hybrid plane tree that developed from the accidental cross-breeding of the American sycamore and the Oriental plane. Tall and stately, with some trees reaching heights of 98 feet (30 m), London planes have greenish-gray trunks, twisted branches and a glossy green foliage. They are popular city denizens, and can be seen dotting the urban landscape in London and Southern England as well as in many parts of Oregon in the USA.
Apart from its attractive appearance, the popularity of the London plane tree in urban areas is due to its hardy and resilient nature. This is a tree that can thrive in almost any type of soil, grow in limited spaces and withstand the effects of pollution. The bark of the London plane has the tendency to slough off in sections, revealing the inner white bark; this regular exfoliation prevents any long-term pollution damage.
The green London plane leaf, which is rather similar to that of the maple tree, has five lobes and changes its color to brown in the autumn. While the London plane sheds its leaves entirely in the winter, it provides shade to city dwellers in the summer. It also offers shelter to an assortment of wild birds.
In May, yellowish male flowers and reddish female flowers grow on separate long stalks on the same tree. The fruit that is then produced usually appears in pairs, and is round with bristly hairs all over; these hairs have been known to cause allergic reactions. The fruit seeds are generally sterile, and new trees are planted using cuttings.
As with most trees, London planes do well with regular fertilization. They have a fast growth rate, and may require frequent pruning to keep them at safe, manageable heights and out of the way of electric or telephone poles. The trees are generally very hardy and long-lived, with some extant specimens known to be over 200 years old. It is necessary, however, to guard against the excursions of pests like the American plum borer and the sycamore lace-bug, and against diseases like anthracnose, leaf scorch, powdery mildew and cankers.
The wood of the London plane tree is known as lace wood. This is in reference to the rather fine, lacy appearance of its grain. It is very hard and durable, and is used to make furniture, flooring, chopping blocks and other items.