PINEAPPLE

Pineapple, common name for a flowering plant family, characterized by unique water-absorbing leaf scales and regular three-parted flowers. The leaves are spirally arranged sheaths or blades, usually occurring in layers. The plant embryos have one seed leaf. The family, which contains more than 2,000 species placed in 46 genera, is almost exclusively native to the tropics and subtropics of America, with one species occurring in western Africa. Many species are now cultivated around the globe, however. The most economically important species is the familiar pineapple. A few species are sources of fiber; others are cultivated for their showy flowers or foliage. The family constitutes an order, and the term bromeliad is used for its members.
Bromeliads exhibit an interesting gradation from relatively primitive to highly evolved forms, with tremendous variations in size and adaptations to their environments. Primitive members include a genus that reaches a height of 10 m (30 ft) and grows high in the Andes. Plants of this genus are terrestrial and have elongated stems, fully developed roots, leaves with narrow petioles (leafstalks), and hairs that retard water loss by providing a dense covering. A second stage in bromeliad advancement is the familiar pineapple, native to South America but now widely cultivated in tropical areas, primarily for its sweet, juicy fruit. Pineapples are terrestrial, growing to about 1 m (about 3 ft), but the stems are short and the petioles are expanded, fitting together to form a water-holding tank at the base of the plant. The leaves act as catchment basins and the tanks as reservoirs. Water is absorbed from the tank as needed by adventitious roots or leaf hairs. An extreme form of bromeliad adaptation is reached in Spanish moss; it has roots only when young, water absorption being taken over by specialized leaf scales. Spanish moss occurs throughout the range of the order as an epiphyte, growing on other plants for support.
Bromeliads with water-holding bases have developed complex relationships with other organisms. Within these reservoirs live ecological communities ranging from unicellular algae and protozoans to aquatic flowering plants and insects, crabs, and frogs. Bromeliads receive dissolved nutrients from their wastes and decomposing remains and are thereby less dependent on roots in the soil.
The pineapple was probably first domesticated in the high plateaus of central South America; it was widely planted for its fiber before Europeans first saw it in the Caribbean. Thereafter, cultivation spread to warm regions around the globe. Leading producers are Thailand, Philippines, Brazil, China, India, Costa Rica, and Nigeria.
Scientific classification: Pineapples make up the family Bromeliaceae and the order Bromeliales. The familiar pineapple is classified as Ananas comosus. The primitive pineapples that grow high in the Andes are classified in the genus Puya. Spanish moss is classified as Tillandsia usneoides.