About Poison Ivy, Oak and Sumac

Get the scoop on four common poisonous plants: Western poison oak, Eastern poison oak, poison sumac, and common poison ivy.
By Terry Krautwurst
June/July 2001
Add to My MSN

Avoid an irritating rash by learning more about common poisonous plants and their prime habitats.

Content Tools

Related Content

Tips and Home Remedies for Treating Poison Ivy, Rash, Blisters and Itching

Bust the myths surrounding poison ivy and decide which DIY remedies are right for you.

Recognize, Prevent and Treat Poison Ivy, Poison Oak, and Poison Sumac

learn what causes poison ivy, oak or sumac rash and how to treat it, as well as tips on recognizing,...

What to Pack for Camping Trips

Make sure your family camping trip is safe and enjoyable by packing the right gear. Originally publi...

In Home Remedies for Poison Ivy, we covered common preventive measures and home treatments for itchy rashes caused by poisonous plants. Now, let’s take a closer look at four common ones.

Western Poison Oak

Toxicodendron diversilobum

Considered the poison oak by some botanists, this plants is common on the Pacific Coast (except for the Olympic Peninsula) from southern British Columbia to northern Baja California. Its three leaflets seem randomly lobed and resemble oak leaves.

Most often found as a spreading, freestanding shrub 2 to 6 feet tall, Western poison oak can also take the form of a tall, climbing vine.

Eastern Poison Oak

Toxicodendron toxicarium; also T. quercifolium

Unlike poison ivy, this low shrub never climbs or produces aerial rootlets. It grows in poor, sandy soils such as those of oak-pine savannas in the Atlantic and Gulf coastal plains and in scrub oak forests in Arkansas and Missouri.

The plant's three leaflets are distinctly roundlobed and resemble the leaves of the common, nontoxic white oak tree. Eastern poison oak berries are white and are borne in clusters.

Poison Sumac

Toxicodendron vernix

This tall shrub prefers low, damp, swampy places and may grow to 15 feet. Like its nonpoisonous sumac cousins, it has compound leaves with multiple leaflets, but there the similarities end. Poison sumac leaves generally have seven to 13 smooth-edged leaflets; nonpoisonous sumac leaves have 11 to 31 toothed leaflets.

Poison sumac yields pale-yellow or cream-colored berries that hang in drooping bunches; nonpoisonous species produce upright, conical clusters of red fruit in typical "staghorn" fashion.

Poison sumac is closely related to the Asiatic lacquer tree, and it is sometimes known as "poison dogwood."

Common Poison Ivy

Toxicodendron radicans 

Poison ivy is found throughout the U.S., except for some desert areas, as well as much of Canada and Mexico. It can be a shrub, ground cover or woody vine covered with hairy aerial rootlets. Generally, in Eastern states the plant's three leaflets are smooth-edged, while varieties in Central and Southeastern regions have notched or toothed leaflets. Some Western varieties have a distinct lobe or "thumb" on one or both sides of each leaflet.

In spring, young leaves often appear glossy and reddish but then turn dull green. Emergence of foliage is followed by greenish white to pale yellow flowers that later yield clusters of small, yellowish-to-white berries.

Post a comment below.


Subscribe Today - Pay Now & Save 66% Off the Cover Price

First Name: *
Last Name: *
Address: *
City: *
State/Province: *
Zip/Postal Code:*
(* indicates a required item)
Canadian subs: 1 year, (includes postage & GST). Foreign subs: 1 year, . U.S. funds.
Canadian Subscribers - Click Here
Non US and Canadian Subscribers - Click Here

Lighten the Strain on the Earth and Your Budget

MOTHER EARTH NEWS is the guide to living — as one reader stated — “with little money and abundant happiness.” Every issue is an invaluable guide to leading a more sustainable life, covering ideas from fighting rising energy costs and protecting the environment to avoiding unnecessary spending on processed food. You’ll find tips for slashing heating bills; growing fresh, natural produce at home; and more. MOTHER EARTH NEWS helps you cut costs without sacrificing modern luxuries.

At MOTHER EARTH NEWS, we are dedicated to conserving our planet’s natural resources while helping you conserve your financial resources. That’s why we want you to save money and trees by subscribing through our earth-friendly automatic renewal savings plan. By paying with a credit card, you save an additional $5 and get 6 issues of MOTHER EARTH NEWS for only $12.00 (USA only).

You may also use the Bill Me option and pay $17.00 for 6 issues.