Rhamnus cathartica, commonly known as common buckthorn, is a deciduous shrub or small tree native to Europe and Asia. It typically grows between 3 to 20 feet tall and features dark green, oval leaves that turn yellow in the fall. The plant produces small, black berries that are not edible for humans but are consumed by birds. This species is often found in disturbed areas, such as roadsides and forests, and can become invasive in some regions, particularly in North America. Rhamnus cathartica can outcompete native plants, leading to reduced biodiversity in affected ecosystems.