So far, I've shown you pictures of the poison ivy leaf on plants trailing over the ground. But they can climb, too....
Picture of poison ivy leaf.
The vines of Rhus radicans produce aerial roots that allow them to climb up rough surfaces. For instance, here it's plainly a vine, growing up a stone wall. This picture of poison ivy leaf again shows that the "leaves of three" warning is true. As you will see later in this photo gallery, however, similar plants also have three leaves, so you need to be armed with more than the traditional rhyme to identify poison ivy.