University of Maryland Extension

Poison ivy

Poison ivy
Toxicodendron radicans

poison ivy

How to identify poison ivy - Learn to recognize the many look-a-likes.

Life cycle: perennial deciduous, woody vine; contains urushiol that causes inflammation, blisters, and itching
Growth habit: climbs trees or structures by aerial roots that form hairy, fibrous ropes; vining habit in shade, more bush-like in sun; leaves have 3 glossy 2-4 in. long leaflets, margins variably toothed, lobed, or nearly entire
Reproduction: seeds spread by animals and birds that eat the fruit and by stems that root
Conditions that favor growth: can invade landscapes, woodlands, wetlands by creeping stems or seeds; thrives under a variety of conditions
Cultural control: identify seedlings and remove early in the season; on trees, sever roots growing up the trunk to eliminate the flow of moisture from roots; always take care to protect all parts of the body from coming in contact with all parts of the plant; never burn the plant as toxins can be inhaled in smoke.

HGIC Publication: (PDF) HG34 Poison Ivy
(PDF) The Ohio State University - Poison Ivy Information

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