It’s time to revisit the red maple tree (Acer rubrum) that I am following for a year as part of Lucy’s meme at Loose and Leafy.
When I think of maple (Acer) trees, I think of their iconic palmately lobed leaves. For as long as I can remember, maples leaves have been my favorite tree leaves – probably because I grew up in New England where maple leaves are loved for their vibrant fall foliage colors.
Although most maple trees have similar shaped leaves, I find it easiest to distinguish among different maple species by looking at their leaves. Many gardeners are familiar with the leaves of the Japanese maple (Acer palmatum), with 5-9 sharply pointed and strongly differentiated lobes.
The maple leaf of the Canadian flag is the sugar maple (Acer Saccharum), which typically has five lobes and rounded notches between the lobes.
When I go for my morning walk, I can easily recognize the maple trees that grow along the river near my house as silver maples (Acer saccharinum) because their leaves have more sharply differentiated lobes (similar to Japanese maples) than do other maple trees that grow in Maine. Growing right next to the silver maple is the Norway maple (Acer platanoides) which is easily distinguished from other maple trees in my neighborhood by leaves that are much wider than tall. The Norway maple is the only maple tree growing in my neighborhood that is not native to Maine. It is a European/Asian native that was introduced to North America in the 18th century and earned a reputation for being able to thrive in difficult growing conditions. In the 20th century, it was widely planted as a street tree to replace elms that succumbed to Dutch Elm disease. Unfortunately, the Norway maple has turned out to be invasive. It is now illegal to plant it in the the neighboring states of Massachusetts and New Hampshire, and the Maine Forest Service “discourages” planting it.
Two other native maple trees that grow widely in Maine (although not in my neighborhood) are striped maple (Acer Pensylvanicum) and the mountain maple (Acer spicatum). These are similar in that their leaves typically have only 3 lobes and the lobes are not strongly differentiated.
Like these, red maple (Acer rubrum) trees sometimes have only three lobes; and when they have five (like the one I am following), the bottom two lobes are often not very differentiated. The three main lobes, however, are separated from one another by fairly deep v-shaped notches (in contrast to the rounded notches on striped maple and sugar maple).
You can see here that the maple leaves on my tree are a bit chewed up by this point in the summer. This is not a cause for concern. These leaves are being eaten by herbivore insects. Some of these are caterpillars that become butterfly and moth pollinators for my garden. Other herbivore insects provide needed food for birds to feed their babies. I’d be much more concerned if my maple leaves looked pristine. As Doug Tallamy (Bringing Nature Home, p. 95) says, “A plant that has fed nothing has not done its job.”