Identifying Trees

What will you see on The Jean & Michael Bevan Tree Walk?

Trees have different shapes, leaves, flowers, buds, and bark, and it is this diversity that makes these gigantic plants interesting. Those differences also provide clues to their identities.

You will see deciduous and coniferous trees, many not seen in other parts of Canada. The climate in Niagara-on-the-Lake supports tree species that are found typically in the southern parts of the United States. Some of these species are known as Carolinian, referring to North and South Carolina.

The Carolinian region in Canada covers the southern part of Ontario and is located between three of the Great Lakes: Lake Erie, Lake Huron, and Lake Ontario.

For those who are interested in learning more, there are online resources, including plant identification apps that identify most plants using a photo of the bark, leaf, or flower and books that identify trees and help us understand how trees communicate.

You can find a list under Resources.

Ask yourself:

Is it a deciduous tree?

Deciduous trees (from the Latin “falling off”) are also called broadleaf trees. They protect themselves against cold-weather damage by losing their leaves for part of the year. Examples of deciduous trees found on the Tree Walk are the Maple, Ash, Oak, and Beech.

Is it a coniferous tree?

Conifer trees are often called “evergreens”, because they retain the green colour in their leaves, called needles, throughout the year. A ‘conifer’ refers to a tree that has cones, which contain the tree’s seeds.

Most conifers do not lose their needles all at once. Instead, they fall out much like the hair on a human’s head. An example of a coniferous tree is a Yew.

What is a fossil tree?

Trees that have no known relatives are sometimes called living fossils. A fossil tree is the only surviving species from an extinct family of plants.

The Tree Walk includes one, the Gingko, with its unique, fan-shaped, leaves.

Native and non-native species – what are the differences?

Some people would consider “native” only those trees, and other plants, that existed before the arrival of European settlers, who brought new species for medicinal or sentimental reasons. The trend to plant non-native trees has continued, both at the individual and local government levels.

With climate change, southern Ontario will see the introduction of many new plant and animal species that could not have survived there even 100 years ago, and this introduction will be not only by humans.

Over time, most non-native species have naturalized, meaning adapted, and have become part of the landscape. Concern arises when a non-native species becomes invasive, meaning that it reproduces quickly and dominates where it grows.

Take a good look at the tree, and consider…

Branch and leaf patterns

Many trees typically found in the climate zone where the Tree Walk is located have alternate branching, meaning the branches are not opposite to each other. Oaks have an alternate branching pattern. Other common trees found on the Tree Walk, like Maples and Ashes, have opposite branching.

Because so many trees on the Tree Walk have one of these two forms, identifying the branch pattern is usually not enough to identify a tree species. But there are other clues. The pattern of how the leaves of deciduous trees and the needles of conifers attach is a quick way to distinguish one species from another.

Leaves on deciduous trees attach to branches by twigs. How leaves attach to the twig of the leaf and their shapes can help identify the tree. There are two types of leaves, simple and compound. You may also see a leaf described as “pinnate”. Pinnate refers to the shape and structure of the leaf. A tree with pinnate leaves has a central rib with attached veins that extend to the edges of the leaves, much like a feather, like the Beech leaves shown below.

A simple leaf has only one part that attaches to the twig, like the Redbud leaf.

Oaks are another example of a tree with a simple leaf but one that looks completely different from the Redbud. While both have smooth edges, sometimes called margins, the oak leaf is glossy and has deep indentations referred to as “lobes”, as seen in the Maple tree below, in autumn colours.

A compound leaf has several parts, called leaflets, that attach to the same twig. The twig attaches to the branch. Compound leaves can grow alternately or opposite to each other on the stem, as can be seen in the Ash branch, below.

There are more clues if you can look at the leaves growing on a tree. With both simple and compound leaves, look to see if the leaves grow in pairs that are opposite to each other on the twig or if they alternate in how they attach. Most leaves grow alternately. If leaves grow opposite to each other, it is likely that the leaves are from a Maple or Ash tree.

Two types of trees found on the Tree Walk whose leaves are, at first glance, similar are the Moraine Sweetgum and the Scarlet Sentinel Maple. This is where looking at the way the leaves grow helps. The Sweetgum leaves grow alternately and the Maple leaves are opposite to each other.

The leaves of Oaks, Beeches, and Sweetgum are glossy, a feature found in trees that need to retain moisture due to hot or cold conditions.

And then, there are leaves that are unlike any others, such as the fan-like leaves of the fossil tree found on the Tree Walk, the Gingko. A fossil tree is the only surviving species from an extinct family of plants.

Needles

Like deciduous trees, conifers can be identified by their needles, their equivalent of leaves. On Pine trees, the needles are arranged in clusters, with two, three, or five needles in each cluster. Spruce and Fir have needles that attach individually and encircle the branches.

Spruce needles are square and sharp. Fir needles are flat, grow in rows, and are softer than Spruce or Pine needles.

Other trees, like the Eastern Red Cedar, have soft, scaly, fragrant needles that grow opposite to each other.

Bark

Looking at the leaf is the easiest way to identify most deciduous trees, but that is an option available for only part of the year. What else can you use? For some trees, like Birches and Beeches, the bark gives the best information.

The bark protects the tree. Trees have highways that run within the tree and carry the nutrients. If the bark is damaged, the nutrient highways will be damaged, and the tree will die. Trees grow outward from the inside of the bark. In northern climates, it is possible to see the growth rings from each growing season.

Some bark is very smooth. The American Beech, for example has smooth, grey, bark when young. With age, the bark can develop fissures and is often compared to an elephant’s skin.

The bark of the River Birch is pinkish-brown, scaly, and comes off the tree in curls. The bark of the Paperbark Maple is cinnamon-coloured and peels away from the tree. Both of these species are found on the Tree Walk. The best known birch is the White, or Paper, Birch.

Fruits, Flowers, and Seeds

There are trees on the Tree Walk with spectacular flowers and seeds. They include the Eastern Redbud, whose pink-mauve flowers are a colour unlike any other, and the Northern Catalpa, with white trumpet-like, flowers and long, pea-like, seed pods. These clues are not always available but when they are, they are a huge help to identification. Easy seeds to identify include the Maple’s keys and the Oak’s acorns.