Toxicodendron pubescens is a deciduous shrub 40-120cm tall known for its poison severity to humans. It reproduces by seeds and rhizomes. The stem is slender, slightly hairy or glabrous, and greyish-brown in colour.
It can be easily identified by its compound leaves with three oak-like leaflets that have lobed or toothed margins.
Poison Oak Classification
- Domain: Eukaryota
- Kingdom: Plantae
- Phylum: Tracheophyta
- Subphylum: Angiospermae
- Class: Dicotyledonae
- Order: Sapindales
- Family: Anacardiaceae
- Genus: Toxicodendron
- Species: Toxicodendron pubescens
- Common Names: Eastern poison oak and Atlantic poison oak
Nativity and Distribution
Poison oak is native to the eastern and central United States. It’s commonly found in states such as:
- Texas
- Oklahoma
- Oregon
- North Carolina
- Alabama
- Florida
Physical Characteristics

- Leaves: Compound, alternate, with three leaflets
- Fruits: Small round clusters of yellowish fruits (drupe)
- Stems: Slender and finely pubescent stems
- Flowers: Green to yellow clusters on leaf axils
- Roots: Rhizomatous root system
Toxicodendron pubescens is a perennial deciduous shrub that can grow up to 1.2m in height. It is easily recognized by its alternate compound leaves with three oak-like leaflets.
As commonly said, “Leaflets three, leave it be”, poison oak is highly poisonous. It can cause dermatitis upon touching broken plant parts or clothing and tools that have come into contact with the plant’s sap.
Young stems are slender, slightly pubescent, and greenish to reddish in colour. When mature, the stems become woody, pubescent, and range from grey to brown in colour.
The leaves are compound, alternate, densely pubescent, 3-foliate, about 2-7 x 7-15 cm, and are located near the ends of the stems.
The leaflets are ovate or elliptic, leathery in texture, with lobed or toothed margins. They are hairy, often vary in size, and resemble the leaves of the White Oak.
In spring, the leaves have a reddish tint, turning to green in maturity. In the fall, the leaves turn to a vibrant scarlet or reddish-orange colour.
Poison oak produces small green to white star-shaped inconspicuous flowers in panicles from the axils of the leaves. An individual flower has 5 petals, 5 sepals, and 5 stamens. Flowering occurs between March and June.
Freshly released seeds are light brown and darker in maturity, oval or round in shape (6-7mm long), and have a hard outer coating.
Reproduction, Dispersal, and Life Cycle
- Life Cycle: Perennial
- Seeds: One fruit produces one seed
- Climate: Continental, tropical, and subtropical climates
- Dispersal: Animals and birds
Toxicodendron pubescens behaves as a perennial and mainly reproduces by seeds and rhizomes. Poison oak is not a prolific seed producer. Each drupe produces one seed. However, these seeds are highly viable and can remain in the soil for many years.
The seeds are mainly dispersed by birds and other animals like deer, woodrats, and rabbits (who like to eat the plant’s fruits) and disperse them to new locations.
Apart from seed germination, poison oak can also spread through underground stems, also called rhizomes. Rarely, the plant may also create new growth once its vines come into contact with the soil.
Similar Plants
- Toxicodendron diversilobum (Pacific poison oak)
- Toxicodendron radicans (Poison Ivy)
- Toxicodendron vernix (Poison sumac)
- Quercus alba (White oak)
Uses
- It has been used as a traditional medicine for dysentery.
- Native Americans made baskets using the plant’s stems and the sap to make black dye.
- Poison oak offers food and habitat for a variety of animal species.
- It is used for soil stabilization.
Impact on Farms and Environment

Poison oak is a weed of thickets, sandy fields, and forests. It provides food and habitat for various birds and wildlife.
While it may invade and thereby reduce grazing land or pastures, the primary concern is the allergic reaction it causes to humans.
T. pubescens, like other members of its genus, contain an oil called urushiol in their stems, leaves, fruit skin, and roots.
After direct contact with the sap or contaminated animals or items like camping gear, gardening tools, or clothing, many people exhibit symptoms such as itching, blistering, swelling, and severe skin redness. Smoke from burning poison oak can also cause life-threatening symptoms such as swelling of the respiratory passage.
Therefore, it is not safe to handle poison oak at any stage of its growth. Remember, the plant changes color throughout the four seasons, so it’s important that you educate yourself to avoid the unpleasant poison oak experience.
Control
- Natural Methods: Grazing and hand-pulling
- Chemical control: Herbicides containing triclopyr and glyphosate
T. pubescens is not easy to eradicate as it can survive mowing and cutting. However, digging and hand-pulling when the soil is moist can help get rid of small plants. Be careful to remove the entire root system, as it can resprout even from the smallest root fragments.
Grazing livestock on poison oak can help reduce growth but will not eradicate them.
For the best control, apply triclopyr herbicide on actively growing foliage or freshly cut stems. For more mature plants, herbicides containing glyphosate like Roundup and Glypro can provide effective control.
When using any herbicide, read the label and strictly follow the instructions for the best results.

Lead Editor for Insight Weeds.