North Carolina Wildflowers, Shrubs, & Trees

by Jeffrey S. Pippen | Back to Jeff's Plant Page | Jeff's Nature Pages


Anacardiaceae > Toxicodendron

Poison Ivy (Toxicodendron radicans) Poison Ivy (Toxicodendron radicans)
Caswell Co., NC
17 June 2006

"Leaves of three, let it be" is a common warning for poison ivy. Variable in appearance, leaflets may be lobed or unlobed, shiny or dull, light green or dark green!

Poison Ivy (Toxicodendron radicans) Poison Ivy (Toxicodendron radicans)
Caswell Co., NC
17 June 2006

All parts of the plant produce the chemical "urushiol", which produces a very itchy rash in many people. Poison Ivy grows along the ground as well as climbs up trees.

Poison Ivy (Toxicodendron radicans) Poison Ivy (Toxicodendron radicans)
Orange Co., NC
15 May 2008

Clusters of pale flowers appear in the spring with fruits developing in the fall. The berries are devoured by birds, helping to disperse this plant widely.

Poison Ivy (Toxicodendron radicans) Poison Ivy (Toxicodendron radicans)
Orange Co., NC
15 May 2008

Flower detail.

Poison Ivy (Toxicodendron radicans) Poison Ivy (Toxicodendron radicans)
Durham Co., NC
15 Oct 2013

"Hairy" vines with branches and leaves along tree trunks are a common sight.

Poison Ivy (Toxicodendron radicans) Poison Ivy (Toxicodendron radicans)
Dare Co., NC
11 Dec 2006

In the fall, Poison Ivy leaves turn bright colors as the leaf chlorophyll breaks down.

Poison Ivy (Toxicodendron radicans) Poison Ivy (Toxicodendron radicans)
Slash Pine flatwoods, Collier Co., FL
24 Dec 2013
Poison Ivy (Toxicodendron radicans) Poison Ivy (Toxicodendron radicans)
Ten Thousand Islands NWR, Collier Co., FL
4 Feb 2015
Poison Ivy (Toxicodendron radicans) Poison Ivy (Toxicodendron radicans)
Caswell Co., NC
17 June 2006

Roots are covered with small rootlets, creating a hairy appearance.

Recent studies at Duke Free Air Carbon Dioxide Enrichment Research Site show that Poison Ivy produces significantly more growth under conditions of higher atmospheric carbon dioxide (CO2). Considering that CO2 is rising in the Earth's atmosphere faster than it ever has, that's just swell.

Poison Oak (Toxicodendron pubescens) Poison Ivy (Toxicodendron radicans)
Orange Co., NC
14 Feb 2010

Poison Oak (Toxicodendron pubescens) Poison Oak (Toxicodendron pubescens)

Very similar to Poison Ivy, Poison Oak grows in sandy habitats, is more hairy, and has hairs structured differently than Poison Ivy. It produces the same skin irritant, urushiol.

Poison Oak (Toxicodendron pubescens) Poison Oak (Toxicodendron pubescens)
Moore Co., NC
10 June 2006

With unripe fruit.


Western Poison Ivy (Toxicodendron rydbergii) Western Poison Ivy (Toxicodendron rydbergii)
Whaley Draw, Missoula Co., MT
3 Oct 2014

Distinguished in part by being a shrub and never a vine, having leaves nearly as wide as long, and entirely lacking aerial roots (amonth other characters).

Western Poison Ivy (Toxicodendron rydbergii) Western Poison Ivy (Toxicodendron rydbergii)
Whaley Draw, Missoula Co., MT
3 Oct 2014

Reported from North Carolina but there is doubt about the validity of its occurrence here. Widespread across North America except in the southeast.


Poison Sumac (Toxicodendron vernix) Poison Sumac (Toxicodendron vernix)
Hyde Co., NC
16 Sep 2006

Small tree with grayish bark and usually dark red rachis supporting the leaflets of the compound leaves.

Poison Sumac (Toxicodendron vernix) Poison Sumac (Toxicodendron vernix)
New Hanover Co., NC
18 May 2008

Poison Sumac (Toxicodendron vernix) Poison Sumac (Toxicodendron vernix)
Hyde Co., NC
16 Sep 2006

The allergic reaction to Poison Sumac is reported to be even worse than for Poison Ivy, although it is the same chemical (urushiol) that causes the reaction.

Poison Sumac (Toxicodendron vernix) Poison Sumac (Toxicodendron vernix)
New Hanover Co., NC
18 May 2008

Clusters of white flowers appear in May and fruits develop in the early fall.

Poison Sumac (Toxicodendron vernix) Poison Sumac (Toxicodendron vernix)
New Hanover Co., NC
18 May 2008



Annotated habitat and distribution information listed above is from Radford, Ahles, & Bell. 1968. Manual of the Vascular Flora of the Carolinas. UNC Press; and from personal observations and discussions with Will Cook, Harry LeGrand, and Bob Wilbur. Common names from personal experience and supplemented by the following resources USDA plants website, Flora of the Carolinas, Virginia, and Georgia, and NatureServe.


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Created on June 25, 2006 | jeffpippen9@gmail.com