Poison Ivy

Green leaves of various grasses and plants.
Leaves of threes, let it be.

NPS Photo

Most people have heard the adage “Leaves of threes, let it be” to help identify poison ivy, but it isn’t the cure all method. Here are some more helpful hints to save you from your next itchy encounter.

How to identify


Poison ivy isn’t the only plant on the Saint Croix National Scenic Riverway that has three leaves. To differentiate them from other plants one must look at the glossiness of the leaves and how they connect to the plant themselves. Poison ivy leaves have a glossier top and a more muted underside with irregular asymmetrical lobing on its edges. The middle of the three leaves are larger and connected to vine by a stem while the other 2 are connected directly to the vine. In spring when poison ivy sprouts the leaves are red and burnt orange turning green later in the season. Leaves also turn red in the fall.


Poison ivy can come in many forms depending on the environment it is growing. If the soil is more rocky and poor poison ivy will be found more as a bush or dense ground cover. If poison ivy is by a tree or a fence line the plant will most likely form vine. The saying “Hairy vine, no friend of mine” is a good way it identify poison ivy in its vine form. To climb, poison ivy sends out many hair-like roots.


The final way to identify poison ivy is by looking at its berries. Poison ivy have bunches of small white berries located near the center of the plant in the fall. The saying “Berries white, run in fright” will help you remember the berries are also poisonous, do not consume.

More information

NIOSH Fast Facts: Protecting Yourself from Poisonous Plants

Last updated: February 7, 2022

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