Rhamnus is a genus of about 150 species (fewer, if some species are placed in Frangula), which are shrubs or small trees, commonly known as buckthorns. It is part of the family Rhamnaceae. Its species range from 1 to 10 meters tall (rarely to 15 m) and are native mainly in east Asia and North America, but found throughout the temperate and subtropical Northern Hemisphere, and also more locally in the subtropical Southern Hemisphere in parts of Africa and South America.