Poison Ivy

Poison Ivy — Toxicodendron radicans (syn. Rhus toxicodendron, Rhus radicans; Poison ivy) is a plant in the family Anacardiaceae. The name is sometimes spelled “Poison-ivy” in an attempt to indicate that the plant is not a true Ivy (Hedera). It is a woody vine that is well known for its ability to produce urushiol, a skin irritant that causes an itching rash for most people, technically known as urushiol-induced contact dermatitis.

The plant is extremely common in suburban and exurban areas of New England, the Middle Atlantic and Southeastern United States. It rarely grows at altitudes above 1,500 meters (5,000 ft), although the altitude limit varies in different locations. The plants can grow as a shrub up to about 1.2 meters (4 ft) tall, as a groundcover 10–25 centimeters (4–10 in) high, or as a climbing vine on various supports. Older vines on substantial supports send out lateral branches that may at first be mistaken for tree limbs.

It is not particularly sensitive to soil moisture, although it does not grow in desert or arid conditions. It grows in a wide variety of soil types, and soil pH from 6.0 (acidic) to 7.9 (moderately alkaline). It can grow in areas subject to seasonal flooding or brackish water.