Identify trees and shrubs from leaves, twigs, bark, and regional keys.

1. Check leaf and branch arrangement

Before comparing leaf shape or color, check: How do leaves, buds, and side twigs attach to the branch?

2. Distinguish simple and compound leaves

A frequent error among beginner botanists is mistaking a single leaflet of a compound leaf for an entire leaf. To determine the true leaf unit, locate the axillary bud on the woody stem:

• Simple Leaf: The blade is single and undivided. An axillary bud sits at the junction where the petiole meets the woody stem (e.g., Oak, Beech, Birch).
• Pinnately Compound: Multiple leaflets line a central axis (rachis) resembling a feather (e.g., Walnut, Hickory, Ash, Mountain Ash). There is never a bud at the base of an individual leaflet.
• Palmately Compound: Leaflets radiate outward from a single central petiole tip like fingers from a palm (e.g., Horse Chestnut, Buckeye).
• Bipinnately Compound: The rachis branches into secondary axes bearing leaflets (e.g., Honey Locust, Kentucky Coffeetree).

Follow a compound leaf to its tip. Some pinnate leaves end in a single leaflet. Others, such as carob (Ceratonia siliqua), end in a pair of leaflets with no leaflet at the tip. That small detail separates many lookalikes.

Do not confuse a deeply lobed simple leaf with a palmately compound leaf. A fig or plane leaf can have deep lobes, but the blade stays joined near the leaf stalk. In a palmately compound leaf, each leaflet is fully separate and can fall on its own.

3. Read the leaf shape, edge, and veins

After arrangement and leaf type, look at the leaf blade itself. Three features help most. The margin is the edge of the leaf. The venation is the pattern of veins. The lobes are rounded or pointed sections of the blade separated by gaps, called sinuses.

4. Examine winter twigs and bark on deciduous trees

After deciduous trees lose their leaves in autumn, examine their twigs and bark:

5. Conifer Needle Anatomy: Pine, Spruce, and Fir

For common pines, spruces, and firs, needle attachment can help distinguish groups. Use it alongside cones, buds, and a regional key; individual traits have exceptions.

When a tree or shrub is in flower, the shape of the flower cluster is another clue: the inflorescence types guide explains catkins, spikes, racemes, and umbels. Where the plant grows matters too; the habitat diversity guide shows how soil, water, and light divide a landscape into distinct plant communities.

Two other conifer groups are common in parks and gardens. True cedars (Cedrus), such as the cedar of Lebanon (Cedrus libani), carry dense tufts of needles on short side shoots. On new long shoots, the needles grow singly. Larches (Larix) have the same tufts but drop all their needles in autumn.

Cypresses (Cupressus), junipers (Juniperus), and arborvitae (Thuja) have tiny scale leaves pressed flat against the twig. Young junipers often have sharp needle-like leaves instead. Check the cones: cypress cones are round and woody, while juniper cones are fleshy and berry-like.

6. Common trees and shrubs in Mediterranean gardens and hillsides

Most identification keys come from North America or northern Europe. In a Mediterranean climate, many common trees are evergreen, with small, tough leaves that resist summer drought. Use a key written for your own region when you can.

Season changes what you can see. After a long, hot, dry summer, many deciduous trees have scorched or early-falling leaves. Pick fresh green leaves for comparison. In a mild, wet winter, deciduous trees such as plane, fig, and pomegranate stand bare. Use their twigs, buds, and bark then.

Oleander needs special care. It is common along roads and in gardens, and all parts are poisonous to people, pets, and livestock. Wear gloves when you prune it. Never burn the cuttings. Fig sap can also irritate skin, especially in sunlight.

7. Worked example: maple or plane tree?

You find a street tree with large leaves that have five pointed lobes. The leaves look like a maple, and an app suggests maple. Here is how to check before you accept that name.

1. Look at the arrangement. Maples have opposite leaves. Plane trees have alternate leaves. On this tree, the leaves zigzag along the twig, so they are alternate.
2. Check the base of a fallen leaf stalk. On a plane tree, the base is swollen and hollow, because it covered the bud like a cap. On a maple, the bud sits in plain view above the stalk.
3. Check the bark. Plane bark flakes off in patches and leaves a cream, green, and gray pattern. Most maples have smoother or ridged bark without this patchwork.
4. Check the fruit. Plane trees carry round bristly balls. Maples carry paired winged seeds.

Alternate leaves, a hidden bud, and patchy bark all point to a plane tree. One mismatch in leaf arrangement is enough to reject a suggestion.

8. When to ask an expert

Some situations need a qualified person, not a key or an app.

• A tree may fall. Dead limbs, deep cracks, fungus at the base, or a new lean near a house or power line need a certified arborist. Do not climb or cut the tree yourself.
• A pest or disease spreads. Many trees of one kind dying in the same area can mean a serious pest. Contact your local agricultural extension service or agriculture authority.
• Someone wants to eat the fruit or nuts. Never eat anything from a tree you identified only from photos or a key.
• A child or pet chewed leaves. Call a poison centre or a veterinarian now, especially if the plant could be oleander. Read the unknown plant safety guide for what to do.