Hi Lavateraguy, thanks for this reference. The article was very interesting; Dodder doing a free service to its hosts, which is in its interests as the host is its meal ticket. Evolution at work before our eyes.
I read about this in a recent British Wildlife - and I recall (though I can't find the reference at the moment) a similar type of communication has been suggested to occur via fungal myceliums (mycelia?) in woodland.
A reference to the mycelia web in woodlands, the wood wide web, as they called it, in the the article in Sc. American.