Poison ivy is a woody vine known for its ability to produce urushiol(ウルシオール), a skin irritant(刺激物)that can cause an itchy rash(発疹). To avoid poison ivy, you'll need to know how to spot it: watch out for a plant that has compound leaves with 3 almond-shaped leaflets(小葉)and grayish-white berries.
Its leaflets have a smooth surface and are usually 3-12 centimeters long, with relatively toothless edges.