Skip Navigation

OW Poison Ivy interp

Chuck's Loop at Oliver's Woods

Leaves of Three, Let it Be!

As you’re walking through Oliver’s Woods it’s important to keep an eye out for poison ivy (Toxicodendron radicans). This infamous plant uses a clever defense mechanism to stop wildlife, and people, from eating it!  An oil-like resin in the plant causes an allergic reaction on skin and can range from mild to severe.  Although not everyone is allergic to Poison Ivy, it is best to avoid it.

The plant can appear as a small ground cover, shrub, or vine. You can see it wrapping around large tree trunks!  “Leaves of three, let it be” is a good rule of thumb, but other, non-irritating plants also have three leaves.  In fact, the box elder, a type of small tree, shares an identical leaf shape, and is found throughout Oliver’s Woods. This can make telling the difference between the two quite tricky, however there is one simple, albeit subtle, difference. Box elders (Acer negundo) have an opposite leaf arrangement, meaning that their leaves are directly opposite of one another on the stem. However, poison ivy has an alternating leaf arrangement, meaning that there is some space between where their leaves sprout on the stem.

Can you spot both in Oliver's Woods?  Can you tell the difference?

If you do happen to accidentally stumble into some Poison Ivy, wash your hands and clothing as soon as possible.

Learn more about Poison Ivy:

 

 

Diagram showing the difference between box elder and poison ivy.

written by Harry Cooper and Pheonix Brown, OU Environmental Studies students

May 2023