Toxicodendron radicans (poison ivy)

Toxicodendron radicans (poison ivy). . , Family: Anacardiaceae (Cashew Family), Distribution: Our eastern poison ivy grows throughout eastern North America, up through Quebec and Ontario and west into Texas and Oklahoma. It is found in most of West Virginia's counties and can be quite a pest here in Upshur County. A western variety covers the rest of the country., Size: Poison ivy can grow as a small herb, a shrub, a trailing vine, or a vine climbing high into trees., Habitat/Description: Although it prefers moist, fertile, well-drained soil, this poisonous perennial can grow in soils that are acid to somewhat alkaline and in rocky, dry places as well as in saturated seeps. The plants are tolerant of drought, flooding, and cold. In Appalachia, they grow at all elevations up to about 3500 feet. Poison ivy is commonly found on the edges of paths, ponds, streams, fields, and yards. Male and female flowers are produced by separate plants; thus only female plants produce clusters of whitish drupes. Plants can be identified by bright green trifoliate leaves with smooth or toothed edges: "Leaflets three, don't touch me!" In fall the leaves turn bright to deep red, sometimes with black spotting. When growing up trees, the vines can be 2 or more inches thick and covered with hairy roots: "Scary if hairy." Poison ivy is toxic because of urushiol, an oily chemical that combines with proteins in the skin of sensitive people to trigger an immune response that can be just irritating or quite severe. Urushiol is released when roots, stems, or leaves are damaged. The typical reaction in most people is contact dermatitis involving itchy rash and watery blisters. Urushiol can be removed soon after exposure with vigorous washing with a strong, degreasing detergent. Liquid oozing from the blisters will not spread the rash. However, urushiol can be transferred from clothing or pets. If plants are burned, the toxic chemical will be present in the smoke, and can affect the eyes or be inhaled and cause extremely serious irritation to the throat and lungs. Although a pesky, native plant for humans, poison ivy is browsed by deer and its fruits are an important food source for game birds, song birds, and small mammals. Virginia creeper, with five leaflets, is often mistaken for poison ivy, as is box elder. All three plants are present in this park., Ethnobotanical Uses: People have made little use of poison ivy. The Houma Indians of Louisiana drank a decoction of the leaves as a tonic, while the Cherokee used the plant as an emetic.