POISON OAKS: Eastern poison oak and Western poison oak

Content of this page

Eastern poison oak:
Also known as Atlantic poison oak;
Toxicodendron pubescens

This variety of sumac, which causes dermatitis the same way as poison ivy is present in the southeast quarter of the United States. Its leaf is reminiscent of white oak. However, unlike Western poison oak, Eastern poison oak is not a creeper. It forms a shrub that can reach three feet (one meter) in height. Its leaves, which come in groups of three (again) are covered with small velvet bristles. Some botanists consider that small shrub as a subspecies to Western poison oak, but it is a separate species.

Eastern poison oak. Copyright Tim Vasquez (Wikipedia English).

Leaf

Like Western poison oak, its leaf is reminiscent of white oak and it is easy to confuse. Its alternate leaves, in groups of three leaflets, are covered with small velvet bristles, which give it its latin term pubescens. Each leaflet can measure up to 6 in (15 cm) long. The appearance of the leaves can vary greatly from one plant to another. In the fall, the leaves turn to orange, like other toxicodendrons.

Eastern poison oak (Toxicodendron pubescens)

Eastern poison oak (Toxicodendron pubescens) hairy leaves.

Trunk and stems

The color of the stems and trunk is a grayish brown. The stems are also covered with small velvet hairs which give them a fuzzy texture. The total height of the Eastern poison oak can reach 3 feet (1 meter) but usually grows to about 2 feet (60 cm) tall.

Eastern poison oak (Toxicodendron pubescens) whole shrub. Copyright alabamaplants.com

Flowers and fruits

The flowers in clusters, at the base of the stems, are pale, yellow green. These flowers are very small, often only half an inch (1 cm) in diameter and appear all throughout spring (April – May). The fruit is small, round, striped (like a pumpkin), and yellowish or greenish. It has small velvet hairs as the leaves. The fruits come in drupes near the flowers, at the base of the stems, and appear in late spring.

Eastern poison oak (T. pubescens) fruits. Source USDA

Propagation

This vigorous plant is propagated by its seeds, located within fruit. Its fruit can drop near the plant or birds can eat the fruit and expel the seeds later in their droppings. Another plant can then grow in this place, if the germination is done correctly. Eastern poison oak can also spread by rhizomes.

Habitat and distribution

Eastern poison oak is present in the southeast quarter of the United States, from Texas to New Jersey including Florida. This plant prefers poor and sandy soils (sandhills, dry hammocks, thickets, old fields) and is found in oak and pine forests. In the Eastern poison oak settlement area, you can also meet eastern poison ivy.

Eastern poison oak habitat area (Toxicodendron pubescens).

Videos about Eastern Poison Oak

Poison Oak – A Survival Guide

Resources about Eastern Poison Oak

Western poison oak:
Also known as Pacific poison oak;
Toxicodendron diversilobum

This toxicodendron is located along the Pacific coast. It comes in the form of a climbing vine or shrub. It is named “oak” because its leaf is reminiscent of white oaks, with some curves on the edge of the leaf. The western poison oak dermatitis looks much like poison ivy. The first European to discover western poison oak was David Douglas between 1825 and 1830 in the Columbia River valley (poor guy!).

Western poison oak growing as a climbing vine.

Leaf

As Eastern poison oak, its leaf is reminiscent of white oak and it is easy to confuse. Its alternate leaves, in groups of three leaflets or rarely 5, 7, or 9, while other toxicodendrons always have only three leaflets. Each leaflet can measure up to 4 in (10 cm) long and has a glossy texture. The appearance of the leaves can vary greatly from one plant to another: scalloped, toothed, or lobed edges. In the fall, the leaves turn to orange or red, like other toxicodendrons.