air plant

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. See epiphyte.

Century Dictionary and Cyclopedia

1. n. A plant unconnected with the ground and apparently living on air: applied to epiphytes, but usually not to parasites. Many epiphytic orchids in cultivation are popularly so named.

Wiktionary

1. n. epiphyte

GNU Webster's 1913

1. (Bot.) A plant deriving its sustenance from the air alone; an aërophyte.

WordNet 3.0

1. n. plant that derives moisture and nutrients from the air and rain; usually grows on another plant but not parasitic on it