The berry is like a cantaloupe melon and is a common fruit throughout the tropics and subtropics, although the species is native to the Americas. Its family is small (4 genera and ca. 30 species) and is traditionally related to the passion flower family (Passifloraceae), which also has parietal placentation. However, it produces mustard oils and molecular data relate it to the other mustard oil containing families, especially to the Moringaceae, which contains the horse-radish tree- and also has parietal placentation.

Papayas contain an enzyme called Papain which aids in digestion and can also be used as a meat tenderizer. In addition, they contain another enzyme, Chymopapain, used to treat spinal disk injuries because of its ability to selectively dissolve certain proteins.