The açaí palm (Portuguese: [aˌsaˈi] ( listen)) (Euterpe oleracea) is a species of palm tree in the genus Euterpe cultivated for their fruit and superior hearts of palm. Its name comes from the Portuguese adaptation of the Tupian word ïwaca'i, '[fruit that] cries or expels water'. Global demand for the fruit has expanded rapidly in recent years, and açaí is now cultivated for that purpose primarily. The closely related species Euterpe edulis (juçara) is now predominantly used for hearts of palm.^{[citation needed]}

Eight species are native to Central and South America, from Belize southward to Brazil and Peru, growing mainly in swamps and floodplains. Açaí palms are tall, slender palms growing to 15–30 meters, with pinnate leaves up to 3 meters long.

The fruit, a small, round, black-purple drupe about 1 inch (25 mm) in circumference, similar in appearance but smaller than a grape and with less pulp, is produced in branched panicles of 500 to 900 fruits. The exocarp of the ripe fruits is a deep purple color, or green, depending on the kind of açaí and its maturity. The mesocarp is pulpy and thin, with a consistent thickness of 1 mm or less. It surrounds the voluminous and hard endocarp, which contains a single large seed about 0.25–0.40 inches (7–10 mm) in diameter. The seed makes up about 80% of the fruit (Schauss, 2006c). Two crops of fruit are produced each year. The fruits can be harvested and consumed.