Poison ivy can be a bit of a chameleon. It looks similar to several common backyard plants including Virginia creeper and boxelder. The leaves of poison ivy may be shiny or dull and the leaf margins may be toothed or wavy, or have no teeth at all. The leaves may be hairy, or have no hairs at all. Its appearance can vary greatly, but in all cases it has compound leaves that consist of three leaflets. The leaflets are 2-5 inches long, green during the growing season and turning scarlet red in fall. The leaves are arranged in an alternate pattern on the stem. The terminal (end) leaflet has a longer stalk than the lateral (side) leaflets.

  
Poison ivy leaves showing variation in appearance. The picture to the right shows poison ivy flowers. Photo credits: Mark Czarnota, University of Georgia, Bugwood.org (left); David Cappaert, Michigan State University, Bugwood.org (middle); and Catherine Herms, The Ohio State University, Bugwood.org (right)

Poison ivy flowers in spring and produces dense clusters of white berries that ripen from late summer through fall and persist through the winter. Poison ivy can take the form of an erect shrub or climbing vine or grow in large colonies along the ground. Poison ivy has aerial rootlets that it uses to attach to the bark of trees. The rootlets have a hairy appearance. Twigs of poison ivy may be covered with fine hairs. The bark of poison ivy is gray.

 
Left, Poison ivy aerial roots. Right, Poison ivy berries in fall. Photo credits: Joseph LaForest, University of Georgia, Bugwood.org (left) and Ohio State Weed Lab Archive, The Ohio State University, Bugwood.org (right)

Virginia creeper, like poison ivy, has brilliant red fall color. Virginia creeper is a vine, closely related to grapes. Its leaves have five leaflets, although very young plants may have some leaflets that appear in threes. The leaves are arranged in an alternate pattern on the stem. It produces small clusters of greenish flowers in spring that mature to blue berries in fall. Although it clings to trees like poison ivy, unlike the distinctly hairy looking aerial roots of poison ivy, Virginia creeper adheres to trees and walls with small, circular pads on the ends of tendrils.