Leaves of three, let them be!
Poison ivy (Rhus radicans) grows plentifully along roadsides, trails and the edges of fields and parking lots, as a vine or a low shrub. The leaves are red in early spring (above), shiny green in summer, and an attractive red or orange in the fall. Each leaf consists of three leaflets.
Most people are sensitive in varying degrees to the sap of this plant, which makes skin itch, blister, and swell.