Rhamnus is a genus of flowering plants in the family Rhamnaceae. It includes various species commonly known as buckthorns, which are found in temperate and subtropical regions around the world. These shrubs and small trees are characterized by their simple leaves and small, often berry-like fruits. Some species of Rhamnus, such as Rhamnus cathartica, are known for their medicinal properties and have been used in traditional medicine. However, certain species can also be invasive, impacting local ecosystems. Overall, Rhamnus plays a role in both ecological and human contexts.