Paullinia cupana

This plant, whose common name is Guaraná, is held sacred by the Sateré Maué tribe in the Brazilian Amazon and has been cultivated by them for hundreds of years. Containing more caffeine than any plant in the world (2-5 times as much as coffee), Guaraná was traditionally their revered source for boosting energy while traversing the rainforest and waging war against distant enemies.

Several myths (collected by Medeiros Marques) in which this plant is a protagonist share a narrative in which a beloved boy (the son of Onhiámuaçabe) is murdered by a jealous, malevolent god. His eyes are buried by the villagers and his afflicted mother waters them with her tears. As a form of consolation, a benevolent god gives the people Guaraná: a wild plant grows from the left eye and a domesticated plant from the right.

The fruit does indeed resemble a human eyeball when it ripens and the red skin opens to expose an underlying white mesocarp that splits to reveal a black, iris-like seed.

Current scientific research (directed by Eugenia M. Kuskoski) attributes Paullinia cupana’s medical properties to the xanthines (caffeine, theophylline, and theobromine) as well as the tannins that the plant contains. It is being used to treat the fatigue associated with chemotherapy and also to reduce the proliferation of tumor cells in patients with breast cancer. Guaraná has been found to be a promising treatment for cognitive problems such as depression, panic disorder and Alzheimer’s disease.