Guarana or Guaraná (IPA: [gu̯a.ra.'na], [gu̯a.ɾa.'na] or [gu̯a.ɹa.'na]), Paullinia cupana (syn. P. crysan, P. sorbilis), is a shrub or small tree in the Sapindaceae family. It is native to Venezuela and northern Brazil. The seed of the Guaraná fruit is a stimulant with thermogenic and diuretic properties.
The guaraná fruit's color ranges from orange to red and contain black seeds which are partly covered by white arils. The color contrast when the fruit has been split open has been likened to eyeballs; this has formed the basis of a myth (see below).