Tree identification by bark
Some trees have distinctive bark. You can use this key to check them against your tree at any time of the year. In winter this may be the easiest way to identify your tree. Click on any image to enlarge it.
The outer bark is dead cork, the inner bark is phloem which carries sugars and nutrients. A layer of cells between the inner and outer bark provides new cork and phloem. The sapwood consists of xylem cells which carry water. The heartwood consists of dead xylem cells.
As the tree diameter increases with age the dead outer bark layer of cork needs to expand. The way the cork layer is produced results in two different bark types – smooth/peeling bark or ridged/plated bark. 12 examples of the former and 15 examples of the later are shown here.
Tree identification by bark – smooth or peeling bark.
In some trees, new cork is produced as a thin layer. The old layer is then lost in the form of dust. This results in smooth bark like the Common Beech and Hornbeam. Some smooth-barked trees, like Cherries, Birches and Planes, shed the thin bark in papery strips or plates.
Tree identification by bark – ridged or plated bark
In other trees the new cork layer is thicker and pushes the old dead cork outwards, which then splits creating ridges or plates. This results in ridged bark like the Sweet Chestnut, Oaks and Redwoods or plated bark such as the Horse Chestnut or Sycamore. The Cork Oak is an extreme example. The cork can be completely removed every 9 years and the tree regrows another cork layer.