Midwest Noxious Weed: Do Not Plant
Species Native to Missouri
Common Name: poison ivy
Type: Deciduous shrub
Family: Anacardiaceae
Native Range: Southern Canada, United States to Guatemala, central China to Taiwan and Japan
Zone: 4 to 10
Height: 1.00 to 3.00 feet
Spread: 1.00 to 3.00 feet
Bloom Time: May to July
Bloom Description: Greenish-white
Sun: Full sun to part shade
Water: Medium
Maintenance: High
Suggested Use: Naturalize
Flower: Insignificant
Leaf: Good Fall
Tolerate: Drought
Culture
Plants grow in a wide variety of conditions including medium moisture soils in sun to shade. Plants should not be grown in the landscape. Eliminate plants with herbicides or remove and destroy plants and root systems by carefully digging them up using rubber gloves and clothing protection for other parts of the body.
Noteworthy Characteristics
Toxicodendron radicans, commonly called poison ivy, is the ultimate weed that no one wants. “Leaflets three, let it be.” It is native throughout the United States and much of southern Canada in a large variety of locations including dry or wet woodlands, thickets, valleys, clearings, fencerows, roadsides and waste ground. It is found in every county in the State of Missouri. It primarily appears as a bushy, erect or trailing shrub or as a woody climbing vine. Climbing vines have aerial rootlets. All parts of the plant contain a toxic plant oil called urushiol which can cause significant and long-lasting skin irritations (allergic dermatitis) in most human beings. Infection can occur from direct contact with the plant, indirect contact (e.g., dog, rake or shoes) or from breathing smoke from a fire of plant material. Some humans seem to be immune. Compound green leaves are alternate, but can be quite variable in characteristics. Each leaf has a stem with three leaflets that are smooth or toothed, rounded or pointed and glossy or dull. Leaflets are glabrous to hairy beneath. Leaves turn red-yellow in fall. Greenish-white flowers bloom May to July. Waxy, creamy-white to yellowish-white berries (drupes) in axillary clusters ripen in late summer and persist into winter. Some birds feed on the fruits. Toxicodendron radicans is synonymous with Rhus radicans.
Genus name means poison tree.
Specific epithet means with rooting stems.
Problems
Do not touch any part of a poison ivy plant. All parts of the plant contain volatile oils that can cause significant skin irritation on direct or indirect contact. Do not burn plant materials because contact with smoke from the burning materials can be just as toxic as touching the plants, and breathing that smoke can be even more hazardous.