Originally Posted by Ametrine
I recall a documentary I watched in the late 1980's (or was it the '90's??) that depicted the response of live plants when another plant is put through a blender. They had electrodes (?) hooked up to the live plant and then fed the blender full of another plant.

They actually got a measurable response from the live plant. Interpretation: Plants know when plants are being tortured/die.

Seriously. I really did see this on tv years ago. Now where the research was conducted or what the outcome was, I couldn't tell you.
The documentary may have been based on the 1970's book, The Secret Life of Plants, a part of which describes experiments in plant sentience. The 1970's also brought the first "Earth Day", recognized annually in the US on April 22.