commensal

pöytävieras, kommensaali

kommensaalinen puhekieltä of a form of symbiosis in which one organism derives a benefit while the other is unaffected
puhekieltä An organism partaking in a English commensal relationship.
2001, (w), (w), w:Canongate Books|Canongate (2003), ISBN 184195392X, page 260:

The tree did indeed grow right out of the algae, as I had seen from the lifeboat. There was not the least trace of soil. Either there was soil deeper down, or this species of tree was a remarkable instance of a commensal or a parasite.