There is no doubt that poison ivy is a woody vine native to North America, and its ability to produce urushiol, a chemical that causes an itching, agonizing rash, is well-known. North America is home to an abundance of poison ivy. Depending on the support used, it can grow as a shrub up to about 1.2 meters (4 feet) tall, a groundcover 10 to 25 cm (4 to 10 in) high, or as a The lateral roots of vines that are older and growing on substantial supports may initially be mistaken for branches of trees. It is an allergic reaction that is caused by poison ivy, which uses urushiols to induce contact dermatitis. Many people have no reaction to urushiol because they don’t have an allergy to the “poison” because they don’t have an allergy. Sensitivity, particularly when it occurs over time, can cause an amazing amount of irritation to those who are affected by it. When poison ivy is burned and the smoke absorbed by the lungs, this rash appears on the lungs lining and can cause extreme pain and potentially fatal respiratory difficulties. The digestive tract and airways can be affected and, in some cases, even die as a result of eating poison ivy. The oil of ururushiol can be retained on dead poison ivy plants and other surfaces for up to five years and will cause the same effects.