Poison ivy (Toxicodendron radicans) is a vine that contains an oily resin known as urushiol. According to the Centers for ...

Poison ivy produces small, white, or yellow berries, and its leaves turn red in the fall. Poison oak is similar in appearance to poison ivy but is usually found as a shrub rather than a vine.

Another plant you really want to avoid touching is the wild parsnip. These look related to the aforementioned giant hogweed, ...