First comes the itching, then a red rash, and then blisters. These symptoms of poison ivy, poison oak, and poison sumac can emerge any time from a few hours to several days after exposure to the plant oil found in the sap of these poisonous plants. The culprit: the urushiol oil. Here are some tips to avoid it.

Recognizing Poison Ivy, Poison Oak, and Poison Sumac

• Poison Ivy: Found throughout the United States except Alaska, Hawaii, and parts of the West Coast. Can grow as a vine or small shrub trailing along the ground or climbing on low plants, trees and poles. Each leaf has three glossy leaflets, with smooth or toothed edges. Leaves are reddish in spring, green in summer, and yellow, orange, or red in fall. May have greenish-white flowers and whitish-yellow berries.
• Poison Oak: Grows as a low shrub in the Eastern and Southern United States, and…