epiphyte

Any plant that grows on another plant or object above the surface of the ground, and has no roots in the soil. An epiphyte does not parasitize the plant it grows on but merely uses it for support. Its nutrients are obtained from rainwater, organic debris such as leaf litter, or from the air.

The greatest diversity of epiphytes is found in tropical areas and includes many orchids. There are few specialized epiphytes in temperate regions, but mosses and lichens are often found growing epiphytically on trees. The family Bromeliaceae is predominantly epiphytic and contains the genus Tillandsia, several of which are sold as air plants.