Toxicodendron diversilobum

Species of flowering plant in the sumac family, Anacardiaceae

Leaves of Toxicodendron diversilobum

Toxicodendron diversilobum, commonly known as Pacific poison oak, is a plant species in the Anacardiaceae family. It is native to western North America, where it is found in a variety of habitats, including forests, woodlands, and grasslands. The plant is well-known for causing contact dermatitis in humans due to the presence of urushiol, an oily compound found in its leaves, stems, and roots.

Description

Toxicodendron diversilobum is a deciduous shrub or vine that can grow up to 3 meters (10 feet) tall as a shrub or climb up to 30 meters (100 feet) as a vine. The leaves are alternate and compound, typically with three leaflets, although the number can vary. The leaflets are glossy green, turning red or orange in the fall.

Foliage at Samuel P. Taylor State Park

The plant produces small, greenish-white flowers in the spring, which are followed by small, white or tan berries. The berries are an important food source for birds and other wildlife.

Habitat and Distribution

Toxicodendron diversilobum is found along the Pacific Coast of North America, from southern British Columbia to Baja California. It thrives in a variety of environments, including coastal bluffs, open woodlands, and chaparral. The plant is adaptable to different soil types and can tolerate both sun and shade.

Toxicity

The primary irritant in Toxicodendron diversilobum is urushiol, a compound that can cause an allergic reaction in many people. Contact with the plant can result in a rash, itching, and blistering. The severity of the reaction varies among individuals.

Contact dermatitis caused by Toxicodendron diversilobum

Ecological Role

Despite its reputation as a nuisance to humans, Toxicodendron diversilobum plays an important role in its ecosystem. The plant provides food and habitat for a variety of animals. Birds, such as the California towhee and the American robin, eat the berries, while deer and other mammals browse the leaves.

Cultural Significance

Indigenous peoples of the Pacific Northwest have historically used Toxicodendron diversilobum for various purposes, including as a dye and in basketry. However, they were also aware of its toxic properties and took care to avoid contact with the plant.

Management and Control

Controlling Toxicodendron diversilobum in areas where it is not desired can be challenging. Mechanical removal, such as pulling or cutting, is often used, but care must be taken to avoid skin contact. Herbicides can also be effective, but they must be used with caution to avoid harming non-target plants.

Toxicodendron diversilobum in its red phase

Related Pages

• Toxicodendron
• Urushiol
• Contact dermatitis
• Anacardiaceae

Toxicodendron diversilobum flowering

Gallery

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  Berries of Toxicodendron diversilobum
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  Pacific poison oak
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  Smaller leaves of Toxicodendron diversilobum