Paullinia is a large genus of flowering plants in the soapberry family Sapindaceae, placed within the tribe Paullinieae and the order Sapindales. The genus comprises approximately 187 accepted species of shrubs, small trees, and climbing lianas, making it one of the larger genera in Sapindaceae.
The genus is distributed across the Neotropics, with its centre of diversity in tropical South America. Species occur throughout Central America, the Caribbean, and the rainforests and tropical dry forests of South America. Members of the genus typically grow in humid lowland and montane forests, where the liana habit is especially prevalent.
Morphologically, Paullinia species share features characteristic of the Sapindaceae: alternate, pinnate or bipinnate compound leaves; small flowers arranged in racemes or panicles; and fruit capsules or berries that often contain seeds with an aril. The climbing species employ tendrils derived from modified inflorescence axes.
The genus is best known through Paullinia cupana, the guaraná plant of the Brazilian Amazon, whose seeds contain exceptionally high concentrations of caffeine and are widely used as a stimulant. Other species have ethnobotanical importance: P. yoco is used as a stimulant and medicine by indigenous peoples of the Amazonian foothills, while P. cururu produces highly toxic saponin-rich sap that has been used as an arrow poison. The flexible stems of P. pinnata have been used to stun fish in shallow pools.
Etymology
The genus name Paullinia honours Christian Franz Paullini (1643–1712), a German physician and medical botanist who encountered and described the genus in the Caribbean during the 18th century.
Distribution
Paullinia is native to the Neotropics, ranging from tropical South America (with greatest diversity in Amazonia and the Andes foothills) through Central America and into the Caribbean. Most species occupy humid lowland or montane forest habitats.
Cultural Uses
Several Paullinia species have significant ethnobotanical uses. P. cupana (guaraná) produces seeds rich in caffeine that are a major commercial stimulant crop, widely consumed across South America and globally in energy drinks. P. yoco is used by indigenous Amazonian communities as a stimulant beverage and herbal remedy. The sap of P. cururu is highly toxic and has been used as an arrow poison by Native American tribes in South America. P. pinnata stems have been used to poison fish in shallow pools, a practice documented by the English naturalist Henry Walter Bates in The Naturalist on the River Amazons.
