Guarana (Paullinia cupana)

Guarana is a tropical vine native to the Amazon rainforest of Brazil. Its grown for its fruit, which are berries somewhat similar to coffee beans but with one of the highest concentrations of caffeine found in any plant. Its used extensively in South America in soft drinks for its stimulant properties. Guarana flowers throughout the summer and fall with fruit ripening in late spring and summer. Male and female flowers arise on the same plant and fruits are formed after pollination. Fruits tend to be reddish-orange and when mature, they open to reveal a dark brown, shiny seed surrounded by a white aril, or a specialty outgrowth from the seed. A mature Guarana fruit resembles an eyeball. Guarana thrives in full sun, warm temperatures and high humidity.