Summary ⁷

Toxicodendron radicans, commonly known as poison ivy (older synonyms are Rhus toxicodendron and Rhus radicans), is a poisonous North American and Asian plant that is well known for its production of urushiol, a clear liquid compound found within the sap of the plant that causes an itching, irritation and sometimes painful rash in most people who touch it. The plant is not a true ivy (Hedera).

Comments ⁸

The foliage of Poison Ivy can irritate the skin of most people, causing redness and blisters. This is caused by a reaction of the immune system to urushiol. People who are immune to Poison Ivy when they are young, can become sensitive to its irritating effects when they become older. Only primates and hamsters are known to have allergic reactions to Poison Ivy, while other animals appear to be immune to its effects. The growth habit of Poison Ivy and the appearance of its leaflets can be highly variable, which sometimes confuses people regarding its identity. At one extreme, Poison Ivy can assume the form of a low little-branched shrub with trifoliate leaves, while at the other extreme it can assume the form of a long woody vine that can swallow up trees. As a vine, its woody stems have a hairy appearance from the abundant aerial rootlets and no tendrils are produced across from the trifoliate leaves. Other woody vines produce simple leaves (e.g., Wild Grapes and Moonseed) or they have compound leaves with 5 or more leaflets (e.g., Virginia Creeper and Trumpet Creeper).

Habitat ⁹

Depth range based on 6 specimens in 1 taxon.

Environmental ranges
  Depth range (m): 0.5 - 0.5
 
Note: this information has not been validated. Check this note. Your feedback is most welcome.

Flower visiting insects of poison ivy in illinois ¹⁰

Toxicodendron radicans (Poison Ivy)
(Bees suck nectar and/or collect pollen; observations are from Robertson and Krombein et al. as indicated below)

Bees (short-tongued)
Andrenidae (Andreninae): Andrena crataegi sn cp (Rb), Andrena forbesii (Kr)
Insect activities:
cp = collects pollen
sn = sucks nectar

Scientific observers:
(Rb) = Charles Robertson

Fire management considerations ¹¹

More info for the terms: frequency, prescribed fire, severity

To date (2012) there were few published recommendations for managing poison-ivies with fire. Because burning live or dead eastern or western poison-ivy plants creates contaminated smoke that, if inhaled, can cause fever, extreme respiratory problems, or even death [108], prescribed fire should be used cautiously in communities with these species. Nonetheless, prescribed fire is frequently applied in communities with poison-ivies (e.g., [3,10,11,68,119,122,126,142,212,277]).

Poison-ivies often occur in canopy openings (see Successional Status), so small, patchy fires may benefit poison-ivies by providing openings that allow them to spread vegetatively or establish from on- or off-site seed sources. Although poison-ivies often increase after prescribed fire, they may also decrease after fire, depending in part of fire timing, frequency, and severity (see Plant response to fire). Viable poison-ivy seeds have been found in the soil seed bank of some forest communities after fire (see IMMEDIATE FIRE EFFECT ON PLANT) [222]. Thus, poison-ivies may establish from the seed bank after prescribed fire. Prescribed fire may temporarily reduce poison-ivy seed production. However, on the Noxubee National Wildlife Refuge, eastern poison-ivy fruit was abundant 4 years after plants were top-killed by a March prescribed fire in loblolly pine-oak forest. The forest had been burned 7 other times during the previous 12 years [126].

Threats ¹²

Comments: Poison ivy adapts to human civilization; probably more abun- dant than in 1492.

Value for rehabilitation of disturbed sites ¹³

Because of abundant rhizomes that create dense patches, poison-ivies may be useful for revegetation of disturbed areas [28]. However, Burrill and others [35] stated that there are many nonpoisonous species that provide equal or better rehabilitation value than poison-ivies.

Sources and Credits

1. (c) Greg Lasley, some rights reserved (CC BY-NC), uploaded by Greg Lasley
2. (c) "<a href=""http://www.pwrc.usgs.gov/WLI/"">USDA NRCS Wetland Science Institute</a>.", some rights reserved (CC BY-NC-SA), http://plants.usda.gov/java/largeImage?imageID=tora2_003_ahp.tif
3. (c) Steven J. Baskauf, some rights reserved (CC BY), http://bioimages.vanderbilt.edu/baskauf/10832
4. (c) Steven J. Baskauf, some rights reserved (CC BY), http://bioimages.vanderbilt.edu/baskauf/10833
5. (c) Steven J. Baskauf, some rights reserved (CC BY), http://bioimages.vanderbilt.edu/baskauf/10834
6. (c) Steven J. Baskauf, some rights reserved (CC BY), http://bioimages.vanderbilt.edu/baskauf/10892
7. (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Toxicodendron_radicans
8. (c) John Hilty, some rights reserved (CC BY-NC), http://eol.org/data_objects/29450678
9. (c) Unknown, some rights reserved (CC BY-SA), http://eol.org/data_objects/32993753
10. (c) John Hilty, some rights reserved (CC BY-NC), http://eol.org/data_objects/32696012
11. Public Domain, http://eol.org/data_objects/24639869
12. (c) NatureServe, some rights reserved (CC BY-NC), http://eol.org/data_objects/29098074
13. Public Domain, http://eol.org/data_objects/24639871

More Info

• iNat taxon page
• Biodiversity Heritage Library
• BOLD Systems BIN search
• Calflora
• CalPhotos
• eFloras.org
• Flora of North America (beta)
• Global Biodiversity Information Facility (GBIF)
• Go Botany
• HOSTS - a Database of the World's Lepidopteran Hostplants
• IPNI (with links to POWO, WFO, and BHL)
• Jepson eFlora
• Maryland Biodiversity Project
• NatureServe Explorer 2.0
• SEINet Symbiota portals
• Tropicos
• USDA PLANTS database
• VASCAN by Canadensys
• World Flora Online

Range Map

(c) Discover Life and original sources, some rights reserved (CC-BY-NC-SA)

iNat Map