Whaddya mean, plants talk?
They don't talk the way we do, but it stands to reason they would have to communicate within and among themselves somehow, to get anything done, right?
When I first became entranced with this notion, it was by reading The Secret Life of Plants, a runaway hit book in the 1970's. Cleve Backster discovered, using instrumentation similar to "lie detector" technology, what looked like a psychic ability of plants to pick up communications from humans and from each other, and to transmit information as well. This research was not replicated, and he was discredited as "woo-woo". When I read Backster's later book on biocommunication, Primary Perception, I thought perhaps in the twenty-first century some progress on the topic had been made. Not so much--apparently he was the only one with a thick enough skin to brave the disdain of mainstream scientists.
However, in the meantime a much more grounded version (forgive the pun) of plant communication emerged. Paul Stamets pioneered the study of biochemical signals transmitted by mycelia, thread-like underground critters of the mushroom variety. He is the one who coined the phrase "mycelia are the internet of the plant world." His best known book is Mycelium Running, describing the medicinal, bioremediation, and gardening uses of various mushrooms. A whole subfield in Botany exists now for the study of mycelia.
In the past few decades the ancient traditional science of permaculture, which depends in part on biocommunication, has entered mainstream gardening. Gaia's Garden is an excellent resource.
Stephen Buhner's The Lost Language of Plants,The Ecological Importance of Plant Medicines to Life on Earth, is a treasure chest of information about plant chemistry and interactions.
Plants send distress signals to other plants
http://www.haaretz.com/print-edition/news/israeli-study-shows-plants-talk-through-the-roots-1.417723
Israeli scientists have uncovered messages transmitted underground - not by enemy agents, but by garden pea plants.
The Ben-Gurion University team discovered that plants can transmit distress signals to each other through their roots. An injured plant "communicates" to a healthy one, which in turn relays the signal to neighboring plants, possibly enhancing the other plants' ability to deal with stress in the future, according to the study, recently published in the periodical PLoS (Public Library of Science One ).
Scientists unable to measure biomagnetic activity in plants as of April 2011
http://newscenter.berkeley.edu/2011/04/07/if-plants-generate-magnetic-fields-they’re-not-sayin’/
In an article that appeared this week in the Journal of Applied Physics, the UC Berkeley scientists describe the instruments they used to look for minuscule magnetic fields around a titan arum – the world’s largest flower – during its brief bloom, the interference from local BART trains and traffic that bedeviled the experiment, and their ultimate failure to detect a magnetic field.
Photo of the style of dowsing rods used by Morgan in Tree Listener and Finding the Lost Coast
http://www.martycain.com/dowsing.html
This is a layperson's first person account of dowsing surprises similar to my own.
Mycelia, the internet of the plant world
"A mycellial “mat” which scientists think of as one entity, can be thousands of acres in size. The largest organism in the world is a mycelial mat in eastern Oregon that covers 2,200 acres and is more than two thousand years old. I think these mycelial mats are neurological networks. They’re sentient, they’re aware, and they’re highly evolved. I say they are sentient, because they produce pharmacological compounds—which can activate receptor sites in our neurons. . .This speaks to the fact that there is an evolutionary common denominator between fungi and humans. We evolved from fungi. We took an overground route. . .
Mycellia are the earth’s “natural Internet.” In the architecture of a mycelium. . . the nodes of crossing. . .conform to the same mathematical optimization curves that computer scientists have developed to optimize the Internet. Or rather, the Internet conforms to the same optimization curves as the mycelium, since the mycelium came first.
Japanese scientists defined “cellular intelligence” in a slime mold which could, after learning the route to the exits of a maze which held food, could navigate directly to those exits on the next trial.
Fungi are exceptionally able to adapt to their surrounding environment; they send out “messenger molecules”—which we know little about—that seem to allow them to anticipate, in advance of actual contact, what nutrients they’re going to encounter."
---Paul Stamets, February 2008, interview in Sun magazine