Ciao Janita, I think that great variations of smell between essential oils offered by different sellers is mostly explained by origins, quality and sometimes even doctoring of the essences.
Little is known about comunication between plants and the existence of aromatic comunication is not to be excluded, but the most evident aspect of olfactory comunication that we can witness is the one taking place between vegetal and animal kingdom and particularly with the insect species which play a major role in the reproducing process of plants.

AbdesSalaam Attar
Compositore Profumiere