Guaraná is the Amazon Rainforest plant whose seeds contain the stimulant compound commonly called guaranine.
Guaraná is a climbing shrub native to the central Amazon, especially associated with Brazil. Its scientific name is Paullinia cupana. The plant produces small fruits that split open when mature, revealing dark seeds partly surrounded by a white covering. The seeds are dried and traditionally ground into a powder or used in beverages.
Guaranine is chemically caffeine, rather than a completely separate stimulant. Guaraná seeds can contain more caffeine than coffee beans by mass, although the amount in a drink depends on processing and serving size. Açaí is a different Amazonian palm fruit, while cacao is the source of chocolate. Indigenous peoples, including the Sateré-Mawé, have long cultivated and used guaraná.