epiphyte

n. plant which grows on another plant but is not a parasite

An epiphyte is an organism that grows upon or attached to a living plant. The term most commonly refers to higher plants, but epiphytic  bacteria, fungi (epiphytic fungi), algae, lichens, mosses, and ferns exist as well. The term epiphytic derives from the Greek epi- (meaning 'upon') and phyton (meaning 'plant'). Epiphytic plants are sometimes called "air plants" because they do not root in soil. However, there are many aquatic species of algae, including seaweeds, that are epiphytes on other aquatic plants (seaweeds or aquatic angiosperms).
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Noun
1. plant that derives moisture and nutrients from the air and rain; usually grows on another plant but not parasitic on it
(synonym) air plant, aerophyte, epiphytic plant
(hypernym) plant, flora, plant life
(hyponym) waxflower, Clusia insignis

adj. epiphytic, of or pertaining to an epiphyte

n. epiphyte, plant which grows on another plant but is not a parasite, aerophyte

(n.)
An air plant which grows on other plants, but does not derive its nourishment from them. See Air plant.
  

(n.)
A vegetable parasite growing on the surface of the body.