Bigleaf Maple

November 1, 2020June 14, 2023
Broadleaf tree, Flora and Fauna, Native to BC
by dhir

Last updated April 23, 2021 (see update at end of post). All photos taken by the author.

Whether you call it a broad-leaved maple, common maple, or big-leaf maple, the tree that these leaves fell from is easy to identify when mature leaves are around. Notice that not every leaf from a bigleaf maple is big, but they do have a characteristic shape of 5 deep lobes.

The easiest way to identify a bigleaf maple is to find, well, a big maple leaf. At this time of year the leaves are changing colour and falling fast so you can look down before you look up. Of all the maple species in our neighbourhood, both native and introduced, bigleaf maple (Acer macrophyllum) may be the easiest to identify.

A bigleaf maple tree surrounded by other tree species in late October.

Leafless branches of a big-leaf maple tree. It still has many samaras attached. Photo taken November 10.

Top branches of a big-leaf maple tree that has lost all its leaves. Look at the samaras and clumps of moss still attached. Photo taken November 10.

I read somewhere that bigleaf maple bark is high in calcium which makes a great place for moss to grow. Perhaps that is why all these ferns are growing on the bigleaf maple trees, too? Plants that grow on other plants without benefiting or damaging them are called epiphytes.

A bigleaf maple tree in a yard. Depending on its surroundings the shape of a tree will be rounder (full sun and lots of space to grow) or narrower (surrounded by other trees so it will have to reach up high for sunlight)

Young bigleaf maple trees have smooth bark but mature trees have deeply vertically grooved greyish-brown bark that is often covered in a healthy jacket of moss (see middle image above). Without leaves it may be difficult to identify a bigleaf maple tree as other trees have similar bark.

The trunk of a bigleaf maple tree. Notice the texture of the bark and the large fungi growing on it.

Maple trees all belong to the genus Acer. It is perfectly acceptable in the world of botany to refer to a tree by only its genus. If you are certain you have found a maple tree but aren’t sure of the exact species, you are correct to just say either, “Look at this beautiful Acer!” or, “Look at this beautiful maple tree!”. Look for maple shaped leaves (lobed, usually with at least 5 deep lobes) and the leaves should be attached opposite to each other. There are other species of Acer whose leaves are not lobed, such as this one, and the next photo, but we will focus on the lobed-leaf species.

Acer griseum, the paper maple, has leaves made up of three leaflets. I only realized this was possibly a maple tree when I found some samaras.

Another species of maple tree. Note the opposite attachment of the leaves. Maybe a vine maple?

A green-leaved species of Japanese maple.

A red-leaved species of Japanese maple. Note the extremely deep lobes on this variety.

Another good indication that you are standing near a maple tree is if you can find the double samara seed pods (samara = winged seed pod), commonly called helicopters because of the way they spin as they fall. Bigleaf maple samaras are attached to each other at an acute angle and have prickly hairs over the seed end. Bigleaf maple samaras are large compared to other maple samaras. Pick up a double samara and throw it and it will likely just fall straight to the ground. Separate the two halves and throw them straight up and as they succumb to the pull of Earth’s gravity they will quickly spin like the rotor of a helicopter. I once dropped a large handful from the top of a playground and filmed in slow motion. Watching this video allowed me to conclude that samaras will rotate both clockwise and counterclockwise. If you are lucky enough to find a bigleaf maple tree heavily laden with samaras, see if it reminds you of a person wearing an excessive amount of jewelry.

A quadruple maple samara.Maple tree with samaras. NOT a bigleaf maple tree but a variety of Japanese maple.

Samaras from left to right: bigleaf maple, other maple, ash

Maple samaras still stuck together. Not sure of the species.

NOT a bigleaf maple samara. Different shape. I don’t know which species, though.

Tiny pink maple samaras from a Japanese maple.

Other maple-shaped leaves that you will find on trees around here will belong to American sycamore, London plane, or sweetgum trees. These leaves are attached alternately and the trees do not have samaras. Instead, they have their seeds in hanging balls. The first time I noticed one of these trees I thought to myself, “What’s wrong with this maple tree? Why does it have balls instead of helicopters?” The next five photos are all of the same tree species, either London plane or American sycamore.

Although these leaves look “maple-ish” I know this is not a maple due to the alternate attachment.

Not a maple tree. Note the alternate leaf attachment.

Another picture of the same tree as above. Notice the maple-like leaf shape.

Leaf from the same tree as above. Although it has a maple-like shape, the stem is relatively short.

The bark of the tree. London Plane tree or American sycamore?

Maple trees, like almost all other broad leaved trees, are deciduous. This means that they grow new leaves each spring and lose them every fall and winter. During late fall and winter deciduous trees may look dead, but if you look closely you will see next spring’s leaf and twig buds already on the tree. Dropping their leaves is a way for trees to get rid of diseases like fungus, get rid of insects that live on the leaves, and protect themselves from winter storms by reducing their susceptibility to breaking a branch when a strong wind rips past them. Less leaves = less wind resistance. So as you see “naked” deciduous trees over the next few months don’t be sad, rather, look more closely at the indications that the tree is still alive and marvel at its evolutionary cleverness in surviving cold, windy winters. Don’t forget to take pleasure in observing the beautiful bright colours of fallen leaves.

A bigleaf maple leaf with large spots of fungus. Deciduous trees drop their diseased leaves each year and grow fresh ones the next spring.

An assortment of fall leaves found in one location. Clockwise from top centre I think the large ones are: Japanese maple, maple, red oak, cherry blossom, brown fig. Not sure of the small yellow ones. Wondering why leaves change colour? Read this website.

Leaves from a tulip tree (liriodendron tulipifera), not a maple tree. I always think these leaves look like cartoon cat heads.

Maple wood is very hard and was extensively used by First Peoples for paddles and carvings among other uses. The leaves were used in food preparation as they impart a nice flavour to other foods. Today you can buy maple smoked foods like bacon and salmon in stores. Maple flowers are edible and taste sweet due to the presence of nectar. I have tasted the nectar of maple tree flowers. Delicious! Bigleaf maple trees, like sugar maple trees, have sweet sap that can be harvested and boiled down to make syrup. The difference is that sugar maple trees have sap with a higher sugar content so it does not have to be reduced as much to get a tasty syrup.

Maple leaf cookie cutter. The leaf in the middle of the Canadian flog is a stylized sugar maple leaf.

Colourful fall maple leaves in a pond. Deep lobes and long stems, I am pretty sure they are almost all maple leaves.

One last link for you: I was recently sent this article about how Norway maples, once prized for their ability to thrive in cities, is now being recognized as an invasive species in Canada. Although our national symbol is a maple leaf, not all maple species should be planted on Canadian soil.

As our days get shorter and so many leaves change colour and fall, get out and look for the biggest maple leaves you can find and identify a bigleaf maple tree!

Bigleaf maple leaves and some other plants, cones, and twigs on a forest floor.

Sources other than the hyperlinks:

“Acer Macrophyllum.” Vancouver Tree Book: a Living City Field Guide, by David Tracey, Pure Wave Media, 2016, pp. 106–107.

“Bigleaf Maple.” Native Trees of British Columbia, by Reese Halter et al., Global Forest-Pure Science, 2003, pp. 85–85.

“Bigleaf Maple.” Tree Book: Learning to Recognize Trees of British Columbia, by Roberta Parish and S. M. Thomson, Canadian Forest Service, 1994, pp. 108–111.

“Broad-Leaved Maple.” Food Plants of Coastal First Peoples, by Nancy J. Turner, Royal BC Museum, 2017, pp. 55–56.

“Broad-Leaved Maple.” Plant Technology of First Peoples in British Columbia, by Nancy J. Turner, Royal British Columbia Museum, 2019, pp. 130–132.

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April 23, 2021

I noticed this past week that the maple trees are flowering. Yes, maple trees have flowers. All deciduous trees have flowers, that’s where their fruit comes from. I challenge you to go look for tree flowers this week and for the next few months.