Which rainforest plant has a central cup that holds water?

The rainforest plant with a central cup that holds water is the bromeliad. Many bromeliads arrange their overlapping leaves into a tank-like rosette that catches rain, dew, and fallen debris.

These water-filled cups create miniature ecosystems in the forest canopy. Insects and other small organisms may live in them, while their waste supplies nutrients to the plant. Some rainforest animals, including tree frogs and mosquito larvae, use the stored water as habitat.

Bromeliads are members of the family Bromeliaceae, which includes pineapples. Most are native to the tropical Americas, although one species, Spanish moss, reaches the southern United States. Many grow as epiphytes on tree branches, but they are not parasites: they use trees for support rather than taking food from them.

A common mix-up is assuming every bromeliad must have a water tank. Tank-forming species are especially famous for this adaptation, while others have narrower leaves and rely more on rainwater running over their surfaces and roots.