The scientific name for poison ivy is Toxicodendron radicans, and the plant is found in North America, Europe and Asia. The most common variety grows up trees or anywhere the ground remains undisturbed. Contact with the leaves can result in a painful rash that leaves the skin horribly inflamed and blistered.
Poison ivy has three leaves. The center leaf is usually about 4 inches long when full grown, has a pointed tip and is attached to a long stem that grows on a woody branch or vine. Two leaves are situated on either side. These have short stems and are usually smaller. The leaves are smooth on the top side and hairy underneath. They often look glossy or wet because of the oil they emit. This oil is what causes an allergic reaction. Poison ivy leaves are green and turn orange to red in the autumn. The leaves are deciduous and fall off in winter.
Flowers and Berries
Poison ivy produces small, greenish white to yellow flowers that are often hidden from view by the leaves. These flowers turn into white or yellow berries that are actually the seeds of the plant. When the berries fall to the ground, the plant reseeds itself. Birds can also carry the seeds. The berries are poisonous to humans.
Poison ivy was discovered by colonists who came to America, and it is said that John Smith is the one who gave the plant its name. It was taken back to England in 1640, but it is unclear whether this was an accidental or intentional transfer. In any case, the plant was used as a medication in England by 1798. A physician studied a patient who was plagued by herpes sores on his wrist for six years. He accidentally got poison ivy on that wrist, and once the inflammation was cleared up the herpes also cleared. Further development of poison ivy as a medication led to cures for rheumatism and paralysis. It continued to be used for all types of skin disorders.
There are some plants that grow in fields and woodlands that are mistaken for poison ivy. Some clematis varieties have a hairy vine like poison ivy, but the leaves only come in twos. Virginia creeper looks very similar, but it has five to seven leaves. Wild blackberry has three leaves, but they are somewhat crinkled and heavily veined while poison ivy leaves are smooth on the top. Wild strawberry also has three leaves, however, the center one does not grow on a long stem, and all leaves are the same size.
Some herbicides will work on poison ivy, but they usually kill everything that grows around it as well. The most effective way to remove poison ivy is to dig the roots out. The tools and clothing of the person digging it out will become contaminated with the poisonous oil. Tools need to be cleaned with bleach. Clothing should cover the entire body, and the areas of clothing that touch the poison ivy should be kept from touching the skin while removing the clothing.
Never burn poison ivy, as the oil will travel in the smoke and infect anyone who comes in contact with it. If a vine is dry and looks dead, do not touch it. The oil can stay on dead vines for many months. If you come in contact with poison ivy, wash the area with cold water and dish soap formulated to fight grease. Never use hot water, as it will spread the oil. Newly infected areas can also be wiped with alcohol or bleach. Pets will not be affected, but the oil will get on their fur and can be transferred to humans when they pet the animal.