Poison ivy

Encyclopedia Article

Poison ivy                                        Toxicondendron radicans (L.) Kuntze

Family: Anacardiaceae (Cashew family)                     
Life cycle: Perennial
Native status: Native to North America
Habitat: Edges of woodlands, field borders              

General description: Woody vine; frequently climbs trees. Leaves have three leaflets with irregular lobes.

Key ID traits: Leaves have three leaflets with irregular lobes (leaves of three, let it be). Older stems growing on trees have aerial roots that give it a hairy appearance.

Similar species: Box elder has leaves very similar to that of poison ivy, but box elder is an erect tree and has opposite leaves. Virginia creeper has similar growth habit and is found in similar habitats, but has five leaflets.

Miscellaneous: All parts of poison ivy contain a resinous compound, urushiol, that cause dermatitis (inflammation, itching, blistering) in most individuals. It can be transmitted in smoke, clothing, pets and other objects that come in contact with the plant.

Trifoliate leaves with irregular lobes. The author is lucky and has a high level of tolerance to urushiol.


poison ivy vine climbing a tree
Poison ivy vine climbing a tree

aerial roots of poison ivy
Aerial roots of poison ivy