Poison ivy is a vine or a shrub that is part of the cashew family. It is harmful, and it grows in many parts of the United states and southern Canada. This plant is usually seen twining around tree trunks or on the ground, although sometimes it grows bush-like. There are several species, including poison oak, which grows in the Pacific Northwest, and sumac, which grows in the eastern United States.
The tissues of these poisonous plants contain an oil, urushiol, that is similar to carbolic acid, which is extreme skin irritant. A person can become poisoned just by removing his or her shoes after walking through poison ivy, or it can be contracted from other people — but only if the oil stays on their skin. Remember, it is not the skin eruption that causes the infection, but the oil from the plant.
If someone comes into contact with the plant, wash the skin thoroughly, hopefully to prevent the oil from penetrating and infecting the skin, thereby causing a rash. If blisters do appear, they will be itchy and can be treated them with calamine lotion, Epsom salts, or bicarbonate of soda. There is a vaccine that can be taken by injection or orally; as with most vaccines, it must be administered before the person encounters the plant.
Poison ivy can be identified fairly easily. Its leaves are red in early spring, then change to a shiny green. They turn yellow, red, or orange in the fall.
Each leaf is made up of three leaflets that have notched edges. Two of the leaflets make a pair, and the third leaf stands alone at the tip of the stalk. There are small green flowers that grow in bunches on the main stem close to where the leaves join. In the late season, poisonous berries appear. They are white and have a waxy look.
Poison ivy and oak are very common. It is hard to eradicate them through chemical spraying or other means.