Paullinia

Paullinia is a genus of flowering plants in the soapberry family Sapindaceae. It comprises numerous tropical species that are predominantly lianas and scrambling shrubs, occurring in tropical forests of the Americas, Africa, and parts of Asia. Members of the genus are typically vines or climbers that use their support to reach light in dense forests.

Morphology and ecology: Leaves are usually compound, and inflorescences bear small, inconspicuous flowers. Fruits are capsules that open to release several seeds; in many species the seeds are covered or embedded in an aril or fleshy cover that aids dispersal by animals. The genus includes a number of species with seeds adapted for animal dispersal and varied fruit presentations.

Economic and notable species: Paullinia cupana, commonly known as guaraná, is the best-known species and is the source of caffeine-rich seeds used in beverages and supplements. Other species are studied for chemical constituents or for their ecological roles in tropical forests. The genus Paullinia is the type genus of the tribe Paullinieae within Sapindaceae and was described by Carl Linnaeus.