The Rhamnaceae are a large family of flowering plants, mostly trees, shrubs, and some vines, commonly called the buckthorn family. The family contains about 55 genera and 950 species. The Rhamnaceae have a worldwide distribution, but are more common in the subtropical and tropical regions. The earliest fossil evidence of Rhamnaceae is from the Eocene. The fruits are mostly berries, fleshy drupes, or nuts. Some are adapted to wind carriage, but most are dispersed by mammals and birds. Chinese jujube is the fruit of the jujube tree (Ziziphus zizyphus) and is a major fruit in China.