[dayglored]

Well, geez, anybody who (like me) has spent time in a greenhouse knows that plants put out chemical "signals" as a result of metabolism, changes in temperature and humidity, insect and human activities, etc. etc. Those signals go out through the air, through common water paths, through the ground, etc. And of course other plants may pick those "signals" up in the form of biochemical reactions.

But to characterize these chemical interactions as "communication" is a bit of a stretch; saying the plants are "talking" is just plain fantasy.

In the 1970's I took part in experiments that seemed to indicate that two "sibling" plants (same species, from the same parent plant) somehow were "connected", such that cutting leaves from one of the plants caused the other plant, a foot or two away, to react.

Of course, these observations were described as "Crying in pain" and "Sympathetic reaction" and so forth. Those of us doing the work thought it was all pretty overblown.

[Jamestown1630]

I once toured a greenhouse where orchids were being raised. They said that at a certain time in the development, you could tell something had happened because of the scent released. (I can’t recall exactly what happened to trigger that, or if it was just the particular orchid they were working on there.)