In winter, what indications do we dispose to identify a tree? Apart from the conifers which, most keep their leaves (exceptions: the Ginkgo and the Larch), deciduous trees have only their bark and their form to help identification. It is very few. It is possible to search at their foot the decomposing leaves, but perhaps they come from another tree. Some trees bear "marcescents"leaves, which remains, even died, on stems: these are the Englosh Oak, the Spanish chestnut and the Beech. Those belong to the same family Fagaceae, that is trees from which fruits are protected by a "cupule" (acorn of the Oak, beechnut of the Beech or chestnut). Other trees keep fruits in winter: samaras in clusters of the ash excelsior, small cones of the alder, glomerules (bowls) of the Plane tree, or of the Davidia (rare), capsules of the Paulownia or clusters of fruits like paper lanterns of the Varnish Tree.

Others finally have a particular form (as the Lombardy Black Poplar which is fastigiate) either the English Oak (tortuous branches) or a straight trunk as the Spanish chestnut or the Wild cherry tree, which help to identify them, on the condition of supplementing this distinctive with the observation of the bark. Here are some examples of barks which will make identification easier:

	the Hornbeam and Hackberry have smooth, fluted barks, possibly blistered. Their colour is grey.
	the trunk of the Beech resembles elephant butts because it is smooth, pleated in the birth of branches.
	the Plane tree has flakes which show, when falling, green or yellow, clear zones of the cambium.
	the Maritime pine has a corky bark, with thick and red scales, while the Scotch Pine has a grey, less thick bark in the bottom, rose at the top of the tree.
	various Birches have a white bark which sheds in long horizontal strips.
	bCherries have a smooth bark in horizontal bands, red-brown, breakthrough with oval "lenticels", through which air enters.
	the Locust tree pseudo-acacia has a gray-brown deeply cracked bark, forming folds in diagonal which thicken as it matures.
	the White Poplar has a grey-green smooth bark, made a hole by small characteristic rhombs, which, in the long, meet, and, on elderly plants, all bottom of the bark is deeply cracked with blackish deep, grey rhombs, which make think of writing characters of Assyrian (cuneate).

For other trees, identification is delicate, because barks are alike. A young subject bears a normally smooth bark which cracks as it matures. So, it is even more difficult to identify a young tree by its bark.

Ordinarily are differentiated :
smooth barks,
smooth slightly cracked ,
smooth, fluted
harsh shedding in strips,
shedding in flakes,
shedding in scales,
fibrous,
cracked (fissures are vertical),
deeply cracked and some other particular (cut up in squares, tormenteds).