eastern poison ivy

(Toxicodendron radicans ssp. negundo)

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

not listed

     
  NatureServe

N5 - Secure

SNR - Unranked

     
  Minnesota

not listed

     
           
Weed Status
   
 

SN – State noxious weed

Specially Regulated

     
 
           
Wetland Indicator Status
     
  Great Plains

FACU - Facultative upland

     
  Midwest

FAC - Facultative

     
  Northcentral & Northeast

FAC - Facultative

     
           
 
Description
 
 

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.

 
     
 

Height

 
 

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.  
     
 
Habitat
 
 

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

 
     
 
Biology
 
 

Flowering

 
 

June to August

 
     
 
Use
 
 

Toxicity

 
 

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.

 
     
 
Distribution
 
 

Range Map – eastern poison ivy

 

Sources

2, 3, 4, 5, 7, 8, 28, 30.

BONAP2 shows this species distributed throughout the state and occurring in most counties. All other sources show a much more restricted range. The map at left does not include the BONAP data.

 
  9/14/2020      
         
 

Nativity

 
 

Native

 
         
 

Occurrence

 
 

Uncommon in Minnesota

 
         
 
Taxonomy
 
  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 (dicots)  
  Subclass Rosidae  
  Superorder Rosanae  
 

Order

Sapindales (soapberries, cashews, mahoganies, and allies)  
 

Family

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

Genus

Toxicodendron (poison ivies and oaks)  
  Species Toxicodendron radicans  
       
 

Subordinate Taxa

 
 

 

 
       
 

Synonyms

 
 

Toxicodendron radicans var. negundo

 
       
 

Common Names

 
 

common eastern poison-ivy

common poison-ivy

eastern poison ivy

eastern poison-ivy

poison ivy

 
       

 

 

 

 

 

 

 

 

 

 

 

Glossary

Entire

Continuous; not toothed, notched, or lobed.

 

Rhizome

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

 

Urushiol

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
       
       
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Slideshows
   
  Poison Ivy
Andree Reno Sanborn
 
  Poison Ivy  
 
About

Toxicodendron radicans

 
     
  Toxicodendron radicans (Poison-Ivy)
Allen Chartier
 
  Toxicodendron radicans (Poison-Ivy)  

 

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Other Videos
 
  toxicodendron radicans
josh veazey
 
   
 
About

Published on Apr 24, 2012

documentary on toxicodendron radicans

   
       
  Toxicodendron radicans (Poison Ivy)
Plantwalks
 
   
 
About

Published on Nov 17, 2012

He won't bring this to class.... would he?

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

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
DNews
 
   
 
About

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
http://news.discovery.com/earth/plants/poisonous-plants-poison-ivy-oak-130617.htm.
"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
http://www.webmd.com/allergies/tc/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
http://www.fcps.edu/islandcreekes/ecology/poison_ivy.htm
"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
http://www.hort.purdue.edu/ext/HO-218.pdf
"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
http://mdc.mo.gov/your-property/problem-plants-and-animals/nuisance-native-plants/poison-ivy-control
"Poison ivy is a woody shrub or vine with hairy-looking aerial roots."

Giant, Toxic Weed Poses Health Risk
http://news.discovery.com/earth/plants/giant-hogweed-invasive-plant-110719.htm
"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
ExploringWithGeorge
 
   
 
About

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
9/7/2020

Location: Milford, MI

eastern poison ivy


     
     
 
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