How to look
A tree is read up close
You don't need to know any botany. You need to look in the right order: first the leaf, then how it joins the twig, and then whatever is on the trunk and on the ground.
Five things, in this order
- Pick several leaves from the outer branches, not from the shoots sprouting off the trunk, which often look odd. Look at a typical one, not the biggest.
- Find the bud. At the base of every leaf stalk there is a tiny bud. If the “leaf” has lots of leaflets and only one bud at its base, it is compound.
- Check whether they come in pairs. Opposite leaves are rare among trees: if you see them, you have already ruled out almost all the rest.
- Look at the ground. Acorns, cones, pods, little balls: what falls lasts much longer than the flowers.
- Touch the bark of a big trunk. On young trees nearly all bark is smooth; the real character comes with age.
What are the leaves like?
Look closely at a twig. If there are no leaves (it's winter), skip ahead to the bark or the fruit.
- Broad and flatFlat, with veins. Most deciduous trees and many evergreens.
- NeedlesThin, stiff, long leaves. Pines, firs, cedars, yews.
- ScalesTiny leaves that cover the twig like roof tiles. Cypresses and junipers.
- Palm frondsEnormous leaves sprouting from the top of a trunk with no branches.
Is the leaf all in one piece?
A compound leaf looks like a small branch with many leaflets, but it falls off whole and has a bud at its base.
- SimpleOne blade on its own stalk. What everyone calls a leaf.
- PinnateA central stalk with leaflets on both sides, like a feather. Ash, walnut, black locust.
- Leaflets made of leafletsThe leaflets are divided again. Silver wattle, jacaranda, honey locust.
- PalmateThe leaflets all spread from one point, like fingers. Horse chestnut.
What is the edge like?
- SmoothThe edge has no teeth or notches.
- ToothedSmall teeth, like a saw. They can be fine or coarse.
- Wavy or lobedLarge, rounded bays and bulges, like an oak leaf.
- PricklyThe teeth end in a spine. Holly, kermes oak, young holm oaks.
How are they set on the twig?
Look at where the leaves (or whole compound leaves) join the twig.
- AlternateOne leaf at each node, first on one side, then the other. By far the most common.
- OppositeTwo leaves at the same node, facing each other. Maples, ashes, olives: few trees do this, so it is a very good clue.
- WhorledThree or more leaves at the same node. Only a few species.
- In bunchesMany leaves bunched on a very short shoot, like a paintbrush. Cedars, ginkgo.
What fruit does it have?
Look on the ground under the tree too.
- Cone
- Small scaly ballA small, round cone, sometimes fleshy like a berry. Cypresses and junipers.
- Acorn
- PodA pod like a bean's. Carob, Judas tree, black locust.
- WingedA dry fruit with a wing that makes it spin as it flies. Maples, ashes, elms, tree of heaven.
- FleshyBerry, cherry, olive
- NutWalnut, chestnut, hazelnut
- Capsule that splits openA dry fruit that splits open to release its seeds. Poplars, eucalyptus, jacaranda.
- Hanging ballsLondon plane
- Bunches of dates
In winter
Without leaves, deciduous trees can be told apart by their bark, the shape of the crown and whatever is left hanging: the balls of the London plane, the pods of the honey locust, the winged seeds of the tree of heaven, the berries of the nettle tree that the birds eat. And underneath, on the ground, there are nearly always a few dry leaves left over from autumn.