The pineapple (Ananas comosus) is a tropical plant and fruit (multiple), probably native to Uruguay, Brazil or Paraguay. It is a tall (1–1.5 m) herbaceous perennial plant with 30 or more trough-shaped and pointed leaves 30–100 cm long, surrounding a thick stem.

The pineapple is an example of a multiple fruit: multiple, spirally-arranged flowers along the axis each produce a fleshy fruit that becomes pressed against the fruits of adjacent flowers, forming what appears to be a single fleshy fruit.

The leaves of the Smooth Cayenne cultivar mostly lack spines except at the leaf tip, but the Spanish and Queen cultivars have large spines along the leaf margins. Pineapples are the only bromeliad fruit in widespread cultivation. It is one of the most commercially important plants which carry out Crassulacean acid metabolism, or CAM photosynthesis.