epiphyte

päällyskasvi, epifyytti puhekieltä A plant that grows on another, using it for physical support but obtaining no nutrients from it and neither causing damage nor offering benefit; an air plant.
1848, John Lindley, A notice of some species of Rhododendron inhabiting Borneo, Journal of the Royal Horticultural Society, Volume 3, http://books.google.com.au/books?id=so0xAQAAMAAJ&pg=PA88&dq=%22Epiphytes%22&hl=en&sa=X&ei=Tw9uUv-jB4jLkwXw-YC4CA&redir_esc=yv=onepage&q=%22Epiphytes%22&f=false page 88,

It has been suggested to me that these fine plants will not prove cultivable, because they are epiphytes.(..)The probability however is, that they do not require to be treated as epiphytes, and that, like orchids, they will grow better if committed judiciously to the earth.

The nature of the surface of a plant also determines the number and sort of Epiphytes which lodge on it.