epiphyte

from WordNet (r) 3.0 (2006)

epiphyte
    n 1: plant that derives moisture and nutrients from the air and
         rain; usually grows on another plant but not parasitic on
         it [syn: {air plant}, {epiphyte}, {aerophyte}, {epiphytic
         plant}]

from The Collaborative International Dictionary of English v.0.48

Epiphyte \Ep"i*phyte\, n. [Gr. 'epi` upon + fyto`n plant, ? to
   grow: cf. F. ['e]piphyte.]
   1. (Bot.) An air plant which grows on other plants, but does
      not derive its nourishment from them. See {Air plant}.
      [1913 Webster]

   2. (Med.) A vegetable parasite growing on the surface of the
      body. Epiphytic