In the seventies, a best-selling book called The Secret Life of Plants presented scientific research from around the world that explored plant intelligence. The chapter which made the biggest impression on me described a retired policeman in New York City, Cleve Backster, who trained people how to use lie detectors. As a lark, he hooked up his plants to a polygraph so he could monitor their responses.
One day, Backster approached his Dracaena Massangeana with a lighted match and acted as if he were going to burn it. Not only did the plant go wild on the graph (Similar to a lie detector) but every other plant in the place did, too. He could hardly believe it. Continuing to experiment, he discovered that the plants responded to his thoughts even when he was miles away. One day, on the New Jersey Turnpike, he decided to let them know, through thought, that he was on his way home. When he arrived, he found that the plants had responded excitedly on the graph at the exact time he was communicating to them. Proximity was not a factor in their ability to sense him!