Hello, some of large plant grows on my north-west facing property in Lake of Bays. It is at the side of a lake, and a wet clay soil. The plant is around 24 inches wide. It gets a mix of sun and shade. It has five leaves on a stem, but I read that poison ivy can have five leaves. I took this photo in mid-May in full sun.
Thank you for writing regarding a plant found on your lakeside property.
For clarity, identification of poison ivy (Toxicodendron radicans) is based on the “leaves of three” rule. For exact visual identification, please see the banner on the Extension of Auburn University site: look for 2 opposite leaves, and a 3rd centre leaf on a longer petiole.
So in answer to your question, what you have found on your property, albeit suspicious, is not poison ivy. But nonetheless, erring on the side of caution does not hurt as much as a severe reaction to urushiol could — the oily liquid compound on all parts of the poison ivy plant — that causes an often-severe itchy rash.
You may also find of interest a Poison Ivy Primer, published by the Smithsonian Institute, wherein you’ll read that there were over 30 to 40 different species of poison ivy named across North America.
Thank you for writing, sure to be of interest to many.
May 21, 2024