"You're Gonna Need an Ocean of Cal-o-mine Lotion"

The misery wrought by poison ivy (Toxicodendron radicans) is reserved exclusively for the human inhabitants of planet Earth. Birds, bears, dogs and other creatures happily eat the leaves, stems and fruit with no ill effects. We suffer by an allergic response to the plant oil (urushiol). This begins immediately upon contact. You can't spread the rash by scratching the blisters. By the time the reaction shows up, the oil is long gone. Soap, no matter what kind, has no effect on the oil. Even though you never touched a plant you can still develop a rash by petting cats and dogs that have roamed through the plants, handling wood that vines once grew on, and using contaminated tools even years later.

With a little determination, gardeners can learn to avoid poison ivy and distinguish it from innocent look-alikes like Virginia creeper.

Beautiful yellow and red autumn foliage of poison ivy.  They love ground that has been disturbed and multiply freely along forest trails.

Usually three leaflets to a leaf, but may have more.
Center leaflet has elongated petiole.

They grow as small shrubs, tall shrubs, and long vines that creep up
into the treetops.