Distinct forms of plane tree can be very close to each other in their gross characteristics. It is possible sometimes to identify a tree from a single character. To identify trees reliably in general though, it is necessary to see many characteristics of a tree.
More detailed descriptions of specific characteristics can be found under the names of the individual trees.
See the photographs for some examples of shapes of trees and their crowns.
Tree shapes can be used as a diagnostic, though this should always be confirmed by looking at other characters. The characteristic shapes for most trees can be clearly seen only in mature specimens, which means at least 50 years old, with a century age being better yet. Be sure that the tree has not been pollarded or had its crown otherwise shaped in the past, as this will usually distort the shape beyond recognition. Many forms have branches with a sinuous or contorted habit; however, if they have been pollarded, straight branches radiate out from the pollard points; younger wood once it starts growing at normal rates may regain the sinuous habit.
Multiple stemmed and low branched crowns are characteristics of many forms of P. orientalis, though this variable species may also be seen as tall specimens on a clean trunk.
An angular branching habit with straight branches is typical of P. x acerifolia 'Pyramidalis'; however this is probably shared by many unnamed clones of P. x acerifolia.
High crowns on tall single trunks with a sinous or contorted branching pattern are usually P. x acerifolia 'London Form' or P. 'Augustine Henry'. These two forms can resemble each other, though they are usually distinct in crown shape from other trees.
The unnamed clones can have all habits intermediate between Pyramidalis and the London Form.
These can vary on a single tree but there are some distinct differences in size and number between varieties.
Large fruits; up to 45 mm across, borne 1 or 2 on a stem – P. x acerifolia 'Pyramidalis'. Similar large fruits are also seen in the 'Palmate leaf form', but they then are 2, 3 or sometimes 4 on a stem.
Medium sized fruits, borne 1 to 4 per stem, with fruits to about 30 mm across, are found in the London plane, and in many unnamed clones of P. x acerifolia.
Many smaller fruits on a stem, generally 2 to 6 per stem (though 3-4 is most usual), and fruits usually about 25 mm across indicates P. orientalis.
Fruits scarce on a mature tree, generally rather small, 1 to 3 per stem; often P. Augustine Henry.
See the photographs for distinctive leaf shapes.
When considering leaf shapes and sizes, it is necessary to make sure that the leaves are typical. Leaves on vigorous fast growing wood such as those on sucker growths, from recently pruned branches or on young trees on rich soils will be atypical, often much larger than usual. Leaves on old weak or dying trees will also be atypical. Leaves also vary in shape through the season, and it is usually best to avoid early leaves and late leaves; typically the third to fifth leaves on an extension shoot will be typical.
The typical medium sized lobes of the leaves of P. x acerifolia can be taken as a standard.
Long lobes, especially in the central lobe, indicate either P. orientalis or its forms.
Broad main lobes indicate P. occidentalis, sometimes hybrid planes close to it such as P. x acerifolia 'Pyramidalis'.
Long finger-like lobes are usually P. orientalis Digitata.
Variegated leaves are usually P. x acerifolia Suttneri, though there are other variegated forms.
Large thin leaves, often with numerous teeth are typical of P. 'Augustine Henry'. The blade of the leaf folds or droops when the leaf is held horizontally. This type of leaf can also be found in vigorous young growth of the London Plane.
Leaf colour can sometimes provide some clues, especially in comparisons between neighbouring trees. P. 'Pyramidalis' has a distinctive deep glossy green leaf, most other forms being a medium green and not so glossy. P. palmate leaf form has a grey brown tinge to the leaves from a distance.
The table below shows gross variations in leaf shape between the three main species
| Tree | Number of distinct leaf lobes | Central lobe |
| Platanus occidentalis | 3-5 | lobe is usually wider than long |
| Platanus x acerifolia | 5, rarely 3 or 7. | lobe is usually about as wide as long |
| Platanus orientalis | 5-7 | lobe always longer than wide |
The texture of the leaves can be a good first guide to the cultivar when seen from a distance in summer.
Certain forms have distinctive winter buds. See the photographs.
Long dark red-purple pointed buds, usually conical in shape - P. 'Augustine Henry' usually. While some other clones also have conical pointed buds, the buds are longest and most beech-bud like in P. 'Augustine Henry'.
Long large ovoid greenish purple buds - P. orientalis (some forms only) .
Ovoid buds, variable, sometimes with a blunt point, red to yellowish red - P. x acerifolia variants, P. orientalis variants.
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9-Jan-2007