Guarana

Guarana ( /ˌɡwɑrəˈnɑː/, from the Portuguese guaraná ), Paullinia cupana, syn. P. crysan, P. sorbilis) is a climbing plant in the maple family, Sapindaceae, native to the Amazon basin and especially common in Brazil. Guarana features large leaves and clusters of flowers, and is best known for its fruit, which is about the size of a coffee bean. As a dietary supplement, guarana is an effective stimulant: its seeds contain about twice the concentration of caffeine found in coffee beans (about 2–4.5% caffeine in guarana seeds compared to 1–2% for coffee beans).