eastern poison ivy

(Toxicodendron radicans ssp. negundo)

Conservation Status
eastern poison ivy
Photo by Travis Miller
  IUCN Red List

not listed


N5 - Secure

SNR - Unranked


not listed

Weed Status

Specially Regulated Plant

In 2010, the Minnesota Department of Agriculture added eastern poison ivy and western poison ivy to the Specially Regulated Plant list.

Must be eradicated or controlled for public safety along rights-of-ways, trails, public accesses, business properties open to the public or on parts of lands where public access for business or commerce is granted. Must also be eradicated or controlled along property borders when requested by adjoining landowners.

Poison ivy is beneficial to many wildlife species, but exposure to it causes severe skin irritation to humans and sometimes to livestock. Smoke from burning it can cause serious respiratory problems.

Wetland Indicator Status
  Great Plains

FACU - Facultative upland


FAC - Facultative

  Northcentral & Northeast

FAC - Facultative


Eastern poison ivy is a climbing or trailing, perennial, woody vine that rises from a usually underground rhizome. It often forms colonies.

Stems are woody and produce abundant, centipede-like aerial roots that grasp the host tree.

Leaves are alternate on long, slender, densely hairy leaf stalks.

The leaves are divided into 3 leaflets. The leaflets may be egg-shaped, with the broad portion at the base where it attaches to the leaf stalk, or elliptic, broadest in the middle and tapering toward both ends. They taper to a point at the tip. They are 1 to 6 long. The two side leaflets are usually shorter than the central leaflet. The leaflet margins may have shallow lobes, they may have rounded teeth, or they may be entire. They tend to be flat, not folded along the midrib. Young leaves are reddish-purple, becoming somewhat shiny and greed with maturity. In the fall the leaves turn yellow, orange, or bright red.

Black spots may appear on any part of the plant. The spots are urushiol, the resin that causes allergic reactions. When the plant is damaged urushiol is exuded in an attempt to seal off the damaged area. The resin is creamy, turning brown-red then black with oxidation.

The inflorescence is a 3 to 4 long cluster with usually more than 25 flowers. The flower has 5 yellowish green petals.

The fruit is a smooth, dull white berry with a few gray stripes. The fruit cluster is stalked and hangs downward.




10 to 36


Flower Color


Yellowish green


Similar Species


Western poison ivy (Toxicodendron rydbergii) is a shrub, not a vine. It does not climb trees. The stems do not have aerial roots. The leaf stalks are hairless. The leaflets tend to be folded slightly along the midrib, not flat. The inflorescence is 4 to 16 long. The fruit cluster is compact and erect.


Woods, wood edges, wooded flood plains. Light shade to full sun.




June to August


Pests and Diseases






The sap of this plant contains the allergenic urushiol. Urushiol is not a single chemical but a complex of five chemicals called alkylcatechols.

Several exposures to the substance may be necessary to impart sensitivity. Research has shown that 85% of all people will develop contact dermatitis after adequate exposure. It usually takes 12 to 48 hours for a rash to develop on a previously sensitized person. In some individuals, a single exposure will cause a reaction. In these individuals, the rash will develop in seven to ten days.

The lesions last 14 to 20 days. Rashes do not spread and are not contagious. Treatment can dry the blisters, reduce swelling, and relieve itching, but will not speed healing.

Contact with the outer surface on an undamaged plant should not cause an allergic reaction unless there is residual urushiol present from a previous injury to the plant or a nearby plant. Contact with a torn leaf, broken or damaged stem or rhizome, or black spot will cause a reaction in those sensitized to urushiol.




Range Map – eastern poison ivy



2, 3, 4, 5, 7, 8, 22, 24, 28, 29, 30.

All sources but one show this species uncommon in Minnesota, with records in a dozen or fewer counties, and those mostly in the southeast quarter of the state. BONAP shows this species distributed throughout the state and occurring in most counties (light green on the map).








Uncommon in Minnesota

  Kingdom Plantae (green algae and land plants)  
  Subkingdom Viridiplantae (green plants)  
  Infrakingdom Streptophyta (land plants and green algae)  
  Superdivision Embryophyta (land plants)  
  Division Tracheophyta (vascular plants)  
  Subdivision Spermatophytina (seed plants)  
  Class Magnoliopsida (flowering plants)  
  Subclass Rosidae  
  Superorder Rosanae  


Sapindales (soapberries, cashews, mahoganies, and allies)  


Anacardiaceae (cashew)  
  Subfamily Anacardioideae (cashews, sumacs, and allies)  


Toxicodendron (poison ivies and oaks)  

Subordinate Taxa






Toxicodendron radicans var. negundo


Common Names


common eastern poison-ivy

common poison-ivy

eastern poison ivy

eastern poison-ivy

poison ivy























Continuous; not toothed, notched, or lobed.



A horizontal, usually underground stem. It serves as a reproductive structure, producing roots below and shoots above at the nodes.



Collectively, the five chemicals (alkylcatechols) in the sap of Toxicodendrons that cause allergic reactions in humans.

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Travis Miller

    eastern poison ivy   eastern poison ivy  
MinnesotaSeasons.com Photos





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  How to ID Poison Ivy: It's My Park Minute
NYC Parks

Published on Aug 21, 2013

Ghanim Khalil, an Urban Park Ranger with NYC Parks in Willowbrook Park, Staten Island, explains how to identify and avoid poison ivy, aka Toxicodendron radicans.

Subscribe to www.youtube.com/nycparksdepartment to learn more about NYC Parks.

Produced by Adrian Sas

  Poison Ivy Will DESTROY You

Published on Jun 16, 2013

Summer's here and with it comes more time outdoors. But be warned: some of those newly sprouted plants are out to get you! Namely, Poison Ivy! Trace shows us what makes this plant one of the wickedest out there.

Read More:

Beware America's Most Poisonous Plants
"Common landscaping plants use lethal chemical warfare on unwary humans. Beware the following rogue's gallery of America's most unwanted weeds and felonious flowers."

Poison Ivy, Oak, or Sumac - Topic Overview
"Poison ivy, poison oak, and poison sumac are plants that can cause a skin rash called allergic contact dermatitis when they touch your skin."

Outsmarting Poison Ivy and Other Poisonous Plants http://www.fda.gov/forconsumers/consumerupdates/ucm049342.htm
"First comes the itching, then a red rash, and then blisters."

Poison Ivy: Toxicodendron radicans
"Poison Ivy is one of the best-known, and probably the most-hated, plant in Virginia. Because most people are allergic to its sap, Poison Ivy can cause a nasty rash and blisters on the skin."

Poison Ivy
"Although poison ivy (Rhus radicans or Toxicodendron radicans) is easily identified and should be avoided, countless people experience a painful introduction to the species."

Irritating to Humans but Good for Wildlife
"Poison ivy is a woody shrub or vine with hairy-looking aerial roots."

Giant, Toxic Weed Poses Health Risk
"The sap of the giant hogweed is extremely poisonous, with the potential to cause burns and even blindness."

Watch More:
Plants Can Hear: http://www.youtube.com/watch?v=ApZ59MSty4o
Glowing Plants: http://www.youtube.com/watch?v=QMDiRKootnI
Vines Hate You: http://www.youtube.com/watch?v=IwPwBaaLCzE

  Poison Ivy

Published on Jul 28, 2013

If you spend time in the outdoors you are going to run into poison Ivy

Toxicodendron radicans, commonly known as poison ivy, is a poisonous North American plant that is well known for its production of urushiol, a clear liquid compound found within the sap of the plant ... Wikipedia




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  Travis Miller

Location: Milford, MI

eastern poison ivy  
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