[link to i.telegraph.co.uk]

In the 1950s and 60s, L. Ron Hubbard used his "e-meter" on various other life forms besides humans, and found that they also responded to stimuli in the same way, thus proving conclusively in a series of scientific examinations that plants are sentient life forms with thoughts, emotions, and intelligence.

His work was unfortunately ignored because mainstream science regarded him as a charlatan due to the popular "Dianetics" craze of 1950, which then morphed into the controversial Churches of Scientology. Subsequent researchers like Cleve Backster, Peter Tompkins and Christopher Bird ("The Secret Life of Plants") directly pillaged LRH's prior groundbreaking work.