A climbing or trailing, deciduous woody vine with 3 leaflets, each about 10cm long. Leaflet margins are toothed, lobed, or entire; leaflets vary in shape but often are egg-shaped. Leaflets stalks (petiolule) are short except on the middle leaflet. When growing as a climbing vine, poison-ivy attaches to trees or rocks by aerial roots. On older plants, aerial roots give the stem a hairy, fibrous appearance. Poison-ivy is the major cause of allergenic dermatitis in the eastern United States. All parts of the plant contain resinous compounds, known as urushiols, that cause inflammation of the skin, blistering, and itching. About 50-60% of Americans are sensitive to urushiols. The toxic compound can be transmitted in smoke and by direct contact with the plant or with objects or animals exposed to the plant, including tools, pets, and clothing. The dermatits response can occur year-round, even following contact with overwintering stems and roots. Urushiols can remain active on objects and in dead plants for over a year.

Plants procuce small yellowish green flowers on axillary panicles from May to June. Greenish to grayish white berries (5mm long) lack hairs and are produced in late summer. They can persist on the plant throughout the winter..

In Autumn, leaves often turn bright red, then drop by midseason. Woody stems persist.

Greenish to grayish white berries (5mm long)

Height

Flowering

Poison-ivy can invade landscapes, disturbed sites, woodlands, and wetlands by creeping stems or seeds deposited by birds. It thrives under a variety of conditions.

Poison-oak is similar but grows more erect, has blunt-tipped leaf apexes, and hairson both surfaces of the blade. Poison-oak is found only from New Jersey southward. Virginia-creeper is similar but has 5 leaflets per leaf and limbs by tendrils with terminal adhesive disks.