The two rules we learned as kids tell you most of what you need to know:
- Leaves of three, let them be.
- Don't be a dope and touch the hairy rope.
The hairy rope: Poison ivy will seek out trees and climb up them. The vines are covered in hairs -- not just on the side of the vine attached to the tree, but all over. The vines can be pencil-thin when young, growing to several inches wide as they age. All of the leaves you see in the picture to the left are poison ivy, not tree leaves. All parts contain the chemical that gives you an itchy rash: the leaves, their stems, and the vine they're growing from. So don't be a dope and touch the hairy rope.
Other forms: Poison ivy can be a shape-shifting, sneaky plant. See, for example, the branch to the right, which was sticking out at least 6 feet from a tree. The entire branch is poison ivy, growing off a vine, not out of the tree trunk. The plants are also strong enough to send up shoots from the ground that can grow to at least 3 feet tall. In these cases, many people assume the poison ivy is a tree or a shrub. It may not be. Repeat after me: leaves of three, let them be.
Avoiding the rash: At this time of year, it's tempting to wear shorts, but you'll be much safer wearing a pair of lightweight pants, especially if you like to go off trail. If you think you might have brushed against poison ivy, wash it off with rubbing alcohol (it breaks up the oils) or soap and cool water. The sooner the better.
More info: Poison-ivy.org
Poison Ivy, Oak and Sumac Information Center
Do you have other tips for recognizing (and avoiding) poison ivy? Please share!