Tips on identification of trees
Identifying trees accurately is important, so that we know what species we are looking at.
There are always distinguishing characteristics that separate one species from another. By examining different parts you will be able to confidently identify the different trees around your home, school or town – in fact anywhere you find them.
All of the parts needed to make a complete identification e.g. leaves flowers and fruits may not be present on the tree at the same time. Sometimes several visits are required.
|When identifying a tree, be careful not to damage it.|
Trees can afford to lose the odd leaf or flower but breaking off branches is both unnecessary and harmful. Cuts should never be made in bark as this allows infections to take hold. Trees should be appreciated, not vandalised!
Identification requires some careful detective work on your part, but it should be fun and easy. Here are some clues to help you:
TREE TYPE Is the tree deciduous or evergreen? Evergreen leaves are usually thick and glossy or waxy but take care – some deciduous trees also have leaves like this.
SHAPE The overall shape of a tree especially the shape of the crown (the ‘head’ formed by the branches) can tell you a great deal about it. You can identify some species just from their outline or silhouette. However, street trees are often pollarded or pruned, which greatly alters their natural shape.
BARK Bark can be helpful for identifying some types of trees. Is it rough or smooth, peeling or scaly? Colour is less helpful but can be distinctive.
TWIGS Features of twigs can be helpful. Sometimes you will need to peel the bark of to see a character. ‘First year’ twigs are the current year’s growth; they are usually quite flexible. ‘Second year’ and older twigs are stiffer.
BUDS These are especially useful in winter. Their shape and colour provides clues to identify. They can also tell you how the leaves that will eventually emerge are arranged on the twig.
INFLORESCENCE All of the flowers and how they are arranged. There are many different arrangements, each with its own technical name, but they can be grouped into a few, similar types such as spikes and clusters. The shape (e.g. conical or domed) and branching of the inflorescence is often important. Some trees have flowers borne singly. Once the fruits have formed, the inflorescence is called an infructescence.
LEAVES Leaves are often the easiest way to identify trees and shrubs. Their shape and arrangement on the twigs can be important (see the drawings below). Leaves vary in size and even in shape on the same tree. When measuring leaves, look for mature ones (not at the tips of twigs) and measure several to obtain an average length.
FLOWERS Look at the shape of the flowers and the number of the petals as well as the colour.
FRUITS The wide variety of fruit shapes makes them useful when identifying trees. Fruits can be dry or juicy. They can also have associated structures, such as the cup that an acorn sits in.
MAKE SURE YOU ARE LOOKING AT THE CORRECT PART
It can be easy to mix up the different parts of a plant such as petals and sepals. Leaves and leaflets are especially confusing.
A compound leaf is composed of several separate leaflets. These may be pinnate (leaflets arranged on both sides of the stalk, like a feather) or palmate (leaflets all radiating from a single point, like fingers from a hand).
A simple leaf has a single blade which may be entire (undivided), toothed, or variously pinnately lobed or palmately lobed.
To distinguish between simple and compound leaves the trick is to look at the base of the leaf stalk where it is attached to the twig. A leaf has a bud in the angle between the stalk and the twig, a leaflet does not.