Poison Ivy on Cottonwood: Taking A Good Look

In early to mid-October in Eliza Howell Park, before most other plants had reached their Fall color peak, Poison Ivy gets my attention. It adds color to the trunks of trees and the fruit attracts birds.

The vine climbs many of the Cottonwood trees inside the road loop, where it is easy to get a good look.

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Poison Ivy is a native species that usually gets talked about for only one reason: stem, leaves, and roots all contain urushiol, which causes a rash reaction in most people who come into contact with it. So the message is to avoid it. But it is safe to look and I have enjoyed getting to know some of its characteristics. I have recently been observing how it grows on Cottonwood trees and each picture here is of Poison ivy on a Cottonwood.

Poison Ivy often grows 20 feet or more up the trunk of a large tree.

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The leaves in fall are red or yellow or orange.

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The fruit is abundant this year. Humans (and other primates, I think) are the only animals that have the rash reaction to the urushiol in Poison Ivy. Birds eat the fruit and deer and insects eat the leaves.

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The craggy bark of Cottonwood trees provides a good surface for the Poison Ivy vines to climb. The vines tend to be hairy, a fact that helps to identify the species during the months of the year when there are no leaves.

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Poison Ivy is not the only colorful vine that climbs trees (the leaves of Virginia Creeper, for example, also turn reddish), but most of the red vines on large trees that a visitor is likely to see within the road loop in the park at this time of the year are Poison Ivy.

This is an ideal time to take a good look and to get a better understanding of its role among the flora and fauna of North America.

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The classic advice of “Look, but Don’t Touch” applies here. Maybe take several good looks.

 

Sugar Maple: A “Leaf Peeping” Walk

When asked recently what my favorite kind of tree is, I said that it depends on the season. Different trees attract me at different times of the year. Twice a year – in March and in late October – the Sugar Maple is at or near the top of my list of favorites in Eliza Howell Park.

In March, it is “sugaring” time (see “Maple Sap Rising,” March 13, 2018); now the leaves demand attention.

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A number of Sugar Maples are found near the park road. The leaves are thick and the branches hang low. (It is a good tree to duck under to wait out a brief rain.) When the leaves turn in the fall, they can be yellow or pink or red, often on the same tree.

Note the variety of colors of the leaves on the ground here, all from the same tree.

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Each fall I check the next two Sugar Maples, growing side by side, to see how both the colors and the time of leaf drop differ.

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These close-up pictures of Sugar Maple leaves, still on the trees, are put together for easy comparison.

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Sugar Maples, native to Northeast North America, are one of the featured trees on many fall foliage viewing (“leaf peeping”) tours in New England and the upper Midwest.

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Healthy Sugar Maples can grow to over 100 feet tall and live up to 300 – 400 years.

Using a method of estimating the age of a tree based on its circumference (a method to be described more fully in the next post), I estimated that the Sugar Maple pictured below is about 180 years old. This means that it began to grow here about the time Michigan became a state.

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The Eliza Howell Sugar Maples mean tasty maple syrup to a number of park neighbors, but that is only one way in which they contribute to the natural beauty and fascinating features of the park.