Annona muricata is a species of the genus Annona of the custard apple tree family of Annonaceae.  The fruit is usually called soursop (salifa in Fiji) due to its slightly acidic taste when ripe. Soursop is widely promoted as an alternative cancer treatment but there is no reliable medical evidence it is effective for treating cancer or any disease.

Soursop (also called graviola, guyabano, and in Latin America, guanábana) is the fruit of Annona muricata, a broadleaf, flowering, evergreen tree. It is native to the tropical regions of the Americas and the Caribbean and is widely propagated. It is in the same genus, Annona, as cherimoya and is in the Annonaceae family.

The soursop is adapted to areas of high humidity and relatively warm winters; temperatures below 5 °C (41 °F) will cause damage to leaves and small branches, and temperatures below 3 °C (37 °F) can be fatal. The fruit becomes dry and is no longer good for concentrate.

With an aroma similar to pineapple, the flavor of the fruit has been described as a combination of strawberries and apple with sour citrus flavor notes, contrasting with an underlying thick creamy texture reminiscent of banana.

Soursop is widely promoted (sometimes as “graviola”) as an alternative cancer treatment, but there is no reliable medical evidence that it is effective for treating cancer or any disease.