Pineapple is a tropical fruit, and also the common name for ananas comosus , the flowering plant from which the pineapple grows. Pineapples are bromeliads, a horticulturally-significant group of plants. Many bromeliads are grown in gardens and hothouses, some are used for fibre, but only the pineapple produces food.
The plant enzyme bromelin, which is present in pineapples as a defense mechanism, can break down proteins and thus is often used as a meat tenderiser. The sap of a pineapple contains high concentrations of bromelin which may cause adverse effects if eaten.