It is usually thought that London plane is a hybrid of Platanus orientalis (oriental plane) and Platanus occidentalis (American sycamore). Some authorities think that it may be a cultivar of P. orientalis. London planes are suited to larger gardens where its presence and majesty can be appreciated. The most striking feature of the London Plane tree is its flaking bark that peels to reveal a lighter colored bark underneath. It can be a messy tree in autumn as the leaves drop and can cause hay-fever as it releases large amounts of pollen in spring. The London plane is very tolerant of atmospheric pollution and root compaction, and for this reason, it is a popular urban roadside tree.