The Secret Life of Plants Peter Tompkins and Christopher Bird
and here is an old video from around the same period in time:
Oryngham means thank you for listening in the language of the plants. It is not a word, as we humans understand it, because its meaning cannot be spoken—nor can it be heard. However, we can experience it by feeling with our bodies and listening to what our ears cannot hear. When we learn to listen to plants without the need to hear them speak, a language that we have forgotten emerges; it is a language beyond words, one that does not wander or pretend or mislead. It is a language that conveys its rich and meaningful expression by bypassing the household of our mind and directly connecting one spirit to another.
Monica Gagliano, PhD
Thus Spoke the Plant Monica Gagliano, PhD
A journey by one scientist who overnight perceived the soulfulness of another living creature, and was taken further into that knowing by the plant beings.
Braiding Sweetgrass Robin Wall Kimmer
Please read this beautiful summary in The Marginalian of some voices that came before and after
Here are some other tree-friendly reviews from The Marginalian:
Finding the Mother Tree Suzanne Simard
Another journey of a person awakening to the realization we sentient beings, called humans, are not alone.
Nature Sojourns 