Poison oak is a low-growing shrub that may be identified by its three-leafleted and lobed leaves that resemble those of an oak tree. Poison oak is native to North America and is also known as Atlantic oak, oakleaf poison ivy and oakleaf ivy.
Poison oak plants grow from 3 to 6 feet on average and thrive in sunny conditions with minimal shade. They commonly grow in uncultivated fields and in areas with little established vegetation. While the leaves usually consist of three separate leaflets, they may sometimes display up to nine leaflets. The leaves are typically 4 to 6 inches long and covered in small, fine hairs, although they may be smooth and glossy depending on the variant of the plant. The leaves are red or green during the spring, turn solid green during the summer and turn yellow and red before they fall off during fall and winter. The stems grow small, whitish-green flowers that turn into small, similarly-colored fruit.
Physical contact with poison oak may result in temporary skin issues caused by allergic reactions to the oils on the surface of the plant's foliage. The affected area may develop an itchy rash and water blisters. Symptoms typically do not last over 10 days, and those affected by the allergens are not contagious.