October | 2015 | The Michigan Nature Guy’s Blog

Eastern Poison Ivy

Recently, I was shown three photos of plants that a person thought were Poison Ivy. Only one was correctly identified. I searched Google Images for Poison Ivy and found several other species that resemble it. The old adage “leaflets three let it be” will keep you away from Poison Ivy and many harmless species.

Western Poison Ivy

There are two species of Poison Ivy in Michigan. Eastern Poison Ivy (Toxicodendron radicans) is found mainly south of the Saginaw-Muskegon line. It is a vine that can creep along the ground or climb trees. It is one of two natives that have aerial rootlets. (The other is Virginia Creeper (Parthenocissus quinquefolia) ). Western Poison Ivy (Toxicodendron rydbergii) grows north of the Saginaw-Muskegon line. It is a small woody plant without aerial rootlets so it never climbs. Both species of Poison Ivy have leaves with three leaflets that are notched with large teeth. The teeth are normally found on half of the leaflet, the half closest to the tip. The alternate (singly along the stem) leaves are smooth above and normally shiny.

Boxelder

Boxelder (Acer negundo) has opposite leaves (leaves in pairs on stem). Its twigs often have a bluish bloom and it is never a vine. Normally its leaves have finer teeth than Poison Ivy. Last weekend, I was at Tawas Point State Park and set up to photograph what I thought was Western Poison Ivy only to discover that it was a Boxelder.

Dewberry and Raspberry (Rubus)

Bramble, Raspberry, and Blackberry (Rubus) often have prickles along the stem. They also might have leaflets with pronounced points. Their leaflet edges are uniformly toothed with fine teeth.

Virginia Creeper

Virginia Creeper (Parthenocissus quinquefolia) has five leaflets not three. It will have aerial rootlets such as Eastern Poison Ivy. If you find it in fruit its berries are purple and not grayish-white like Poison Ivy

Hog Peanut

Hog Peanut (Amphicarpaea bracteata) has three leaflets but they are untoothed. It rarely climbs trees and has a finer stem then Poison Ivy.

Common Strawberry

Common Strawberry (Fragaria virginiana) has blunt leaflets with their teeth uniformly spaced. Their leaf stems are furry and they never creep like Poison Ivy vines do.

Fragrant Sumac

Fragrant Sumac (Rhus aromatica) leaves have numerous blunt teeth and small lobes on their edges. Catkins, or buds of catkins, often appear at the ends of the stems.

The best time to learn the lookalikes is when they are flowering or fruiting. Study their leaves and the leaves of Poison Ivy. If in doubt, don’t touch it.

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Good Garden Bugs: Everything you need to know about beneficial predatory insects is a new guide by Mary Gardiner. But, it is more than a guide to identifying and attracting beneficial insects. It also explains the life cycles and unique behaviors of these insects. Although this is not a gardening blog I wanted to call attention to this book because it meets the purpose of this blog which is to get people out and looking at nature.

Wasp Mantid Fly

This book is packed with useful information. The photographs are excellent and aid in identification. Most are taken from the website bugguide.net. I have mentioned this site in previous blog posts and use it all the time. Many of the species are illustrated at different stages of their life cycle. Some life cycles are shown with line drawings. The section on extrafloral nectaries is fascinating. Extrafloral nectaries are “glands found on leaf surfaces and margins, petioles, leaf and flower bracts, and sepals that provide nourishment to natural enemies”. I need to study these more. Another section shows how to build a bee or wasp hotel to provide shelter and nesting areas for these beneficial insects.

Lacewing larva covered with parts of prey and sand

The insects selected for the guide include most of the common insect species and a few interesting but rarer species such as the mantis fly. Using this guide I identified an insect that I photographed two years ago. It is a Lacewing larva. The feather-legged fly is listed (see blog post). A concise introduction to the wasps helped me to sort out that group. A chapter is devoted to insects of the water garden. Spiders, Predatory Mites, Pseudoscorpions, Scorpions, and Centipedes are also included. Bees and Bumblebees are not included because, while they are beneficial insects, they are not predatory.

The author grew up in Michigan and is currently an associate professor in the department of entomology at Ohio State University. This guide is written with the layperson in mind and is accurate without being overly technical. My only complaint is that the scientific names used in this book are not indexed. This guide should prove useful throughout Michigan. Look for it at your local library.
Copyright 2015 by Donald Drife

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The Michigan Nature Guy’s Blog

To get people looking at, enjoying, and understanding the natural world around them.

Monthly Archives: October 2015

Poison Ivy Lookalikes

Good Garden Bugs: A Review