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Arborists Advise: How to Identify Your Trees

Updated: May 28

How to ID your trees by looking at bark, leaves, needles, scales… and apps

Are you struggling to identify your trees in your back garden? Not sure what you have, how big it will grow, when you should prune it and how to take care of a tree? Well the first thing you need to know is how to identify it!

There are over 23,000 different types of trees in the world, from towering Sequoias to tiny bonsai trees; and 7,500 different types of these trees are found in Ireland. All trees have clues and features that can help with identification. You just need to know what to look out for. This quick guide will give you a few basic hints and tips on tree recognition.


Read below to find out all the basic principles of how to ID your trees! If you still need advice from professional and experienced arborists - tree surgeons, feel free to contact us.

A silver birch tree
A silver birch tree

Tree Morphology

Woody plant identification is based on morphology. This is the size, shape and appearance of your tree. Some trees are easily recognisable from afar: Compare the distinctive heavily-spread crown of an Oak, to the light narrow shape of a silver birch, for example, very different!



An Oak tree
An Oak tree

The morphology of a tree can be affected by its location. Trees in woodland can’t spread out, so they often have narrower crowns compared to trees in parks with lots of space around them.



Leaves of a tree


Leaf type, shape, appearance, texture and colour are all key characteristics when identifying trees. They are also often the most obvious feature, particularly in spring and summer.


The leaves of broadleaved trees fall into two basic types - simple and compound. Recognising the difference between a simple leaf ad a compound leaf is the first step of identification. A leaf is determined by the presence of a bud where it attaches to a stem.



Stem & Leaf Diagram
Stem & Leaf Diagram

A Simple Leaf


A 'simple' leaf, is what you would commonly recognise a leaf to be. It is just a single leaf that is only made up of one part. It is not subdivided into leaflets (1 blade, needle etc). It is always attached to a twig by its stem or the petiole. The margins, or edges, of the simple leaf can be smooth, jagged, lobed, or parted. Lobed leaves will have gaps between lobes but will never reach the midrib.


A 'simple' leaf formation
A 'simple' leaf formation

Common trees with Simple Leaves

  • Sycamore

  • Hawthorn

  • Maple

  • Birch

  • Oak



A Compound Leaf

In contrast to a single leaf, a compound leaf has two or more leaflets, which are attached to the middle vein and have their own stalks. It is sometimes confusing to know whether you're looking at a leaf or a leaflet. In these situations, locate lateral buds along the twig or branch. All leaves, whether simple or compound, will have a bud node at the place of petiole attachment to the twig. Compound leaves have a bud node at the base of each stem or petiole but no bud node at the base of each leaflet on midribs and the rachis of the compound leaf.


Compound Leaf Formation
Compound Leaf Formation

Compound leaf formations can either be 'palmate' or 'pinnate'.

  • Pinnate are feather-shaped where leaflets are attached in pairs along the central vein.

  • Palmate are palm-shaped, like the outstretched fingers of a hand.


Getting confused ? Look at the images below to better understand the different arrangements!



A Palmate Compound Leaf Formation
A Palmate Compound Leaf Formation

Common trees with palmate leaves

  • Horse chestnut

  • Maple (Acer sp.)\

  • Sweetgum (Liquidambar styraciflua)

  • Sycamore (Platanus occidentalis)

A Pinnate Compound Leaf Formation
A Pinnate Compound Leaf Formation

Common trees with pinnate leaves

  • Rowan,

  • Ash

  • Elder

  • Hickory

  • Walnut

Identifying some tree species requires recognising relatively minor leaf, bud or twig characteristics. For example, the type of leaf margin, the shape of the leaf base or leaf apex, the presence of hairs on the upper or lower leaf surfaces, or even the colour of the twigs.


Look at the image below to see the different leaf margins. You will recognise some leaves, such as the Oak leaf, which is lobed and the Beech tree has serrated margins etc.

Leaf Margin Diagram
Leaf Margin Diagram- A useful tool when identifying leaves

One little trick arborists like to use in identification, is to narrow down the genus of the tree, based on whether the tree has an ‘opposite’, ‘whorled’ or ‘alternate’ leaf and bud arrangement.



Leaf Arrangement Diagram
Leaf Arrangement Diagram- Another useful tool when identifying leaves on trees!



Evergreen trees all look the same! Not for a professional arborist.


If the foliage on the tree is needles or scales then you are probably looking at a conifer. A conifer is a cone-bearing tree. The needles and scales of conifers are also considered types of leaves.


Common Conifers include:

  • Pine

  • Fir

  • Cypress

  • Larch and

  • Spruce families.

Diagram showing the difference between needles and scales
Difference between needles and scales

Needles & Scales


Most conifer trees have needles or scales present all year that can be used for identification. One of the few exceptions is European larch which loses its needles in winter. Pines, Spruces, Firs, Cedars and Larches have needles. They can be different shapes, sizes and be arranged differently on twigs. Pines have needles, usually borne in clusters of two, three or five. Spruces and Firs produce their needles singularly. Spruce starts with an ’S’, making it easier to remember that their needles are short, sharp, single and square.


The needles of firs detach from the stem, leaving a circular ‘pad’, whereas Spruce needles leave a tiny stalk. Other conifers may have awl-like or scale-like foliage. Flattened needles could mean your tree is a Yew or whorls of three needles may be indicative of juniper. Larch needles are arranged in clusters. Species of the cypress family have scales. These are flattened and shield-shaped that overlap on the twigs.

Palms are grasses not trees!


Palms are classified as monocots, and as such are related to grasses. The variety within palms is remarkable. There are thousands of species, different one being native to each different continent (except Antarctica). Despite being related to grasses, Palms can be identified in similar ways to trees. Their leaves - known as fronds, are compound and either in pinnate or palmate formation.

Most of the common species are single stem (instead of multi-stemmed). Some are shrubby, others are vine-like. There are species that can grow over 200ft (65m) tall! Coconut palms produce the largest seeds of any plant, and they float allowing them to travel from island to island.



Palm trees in Bamboo Park, Glengarriff, Ireland.
Palm trees in Bamboo Park, Glengarriff, Ireland.

Most palm species are native to tropical or sub-tropical rainforests, but some do survive here in Ireland! The loop through wild country in the Ring of Kerry area, around the Iveragh Peninsula, have palm trees. Areas like Glengarriff, who luxuriate in the warm waters of the gulf stream, have wonderful displays of palms for example!



Bark


In the winter time , when leaves aren’t present on deciduous trees, then bark can be a great aid to identifying trees. Take a closer look at the appearance, texture, markings and colour of the bark. What colour is it? Bark isn’t just brown, it can be grey, white or green! It develops over time as the tree ages, becoming more interesting, gnarled, and fissured as the tree gets older. Does your tree’s bark have a pattern of ridges or depressions, peeling flakes or is it fissured, smooth or shiny?


There are some brilliant apps for bark identification, so you can download one of these if easier. Good identification apps are listed at the bottom of this page.


The difference between young Oak bark and ancient Oak bark


Young Oak tree
Young Oak tree
Ancient Oak tree
Ancient Oak tree


Tree identification: Use all your senses!


Tree identification is sometimes based on more than visual senses. Smell, and even taste, may be useful to determine unique characteristics of twigs, leaves, flowers or fruit. Tropical arborists often have to consider the colour the sap, or other obscure characteristics to distinguish similar looking species.


All though using leaves as your identity giver is the easiest option; it is important to use all available information to identify your tree. If you think your leaf looks like an Oak leaf, but you really aren’t sure, then take a step back and look at the tree’s form. An Oak tree, to use this example, will have a spreading habit and may have Spanish moss growing on it.

Using Books, Keys & Tech


Many trees and shrub reference books use identification keys. This is the premise that most tree identification apps work off too. These are used to systematically obtain the identification of the plant, by analysing the shape, texture, arrangement of leaves, bud characteristics and twig shapes (i.e the morphology of the tree).



A few notes of caution about relying on keys:

  1. A certain level of expertise and understanding of the terms used in keys is necessary (all explained above!)

  2. Owing to seasonal differences in plant colour and morphology, the plant may not match its written characteristics annotated in the book, or uploaded onto app software. Sometimes tree identification requires a more… holistic approach.

  3. Some apps and books only have generic trees listed, rather than trees specific and native to your location; and thus may not recognise them. Nevertheless, it is always helpful, and quite fun to use books and apps for a go-to reference point.

Good apps for Tree identification

Woodland Trust - British Trees ID app

Leafsnap - Plant identification app

Plantnet - Plant identification app


How can an arborist help?


Arborists are excellent at identifying trees as they have been trained to have the fundamental, and essential, knowledge of woody plant anatomy. Although arborists usually concentrate on leaves and overall form when identifying trees and shrubs; botanical identification is often based more on the reproductive characteristics - i.e the flowers and the fruit.


A good arborist has learnt to identify trees using many characteristics- obvious ones that you can see too, if you take a good look at your trees. These include bark, buds, twigs, leaves, flowers, fruit and even scent! Spotting key characteristics enables an arborist to identify trees in any season- even when deciduous trees are all stripped back and bare in the winter time.

We hope this blog will aid in your understanding of tree terminology. If you feel totally out of your depth then do not hesitate to contact us, as we have trained arborists who will happily help you out!

Contact us today and we will help you ID your trees!

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