If you have ever read The Secret Life of Plants, or the Secret Life of Soil, you know that there is much more going on with our plant kingdom than just decoration or food provision. This intriguing article adds to understanding about the recptivity and sensitivity of plants, and why.
http://www.dailygood.org/view.php?sid=265
If you are interested in further reading about plants, Conscious Gardening by Michael J. Roads, and The Elves of Lilly Hill Farms, by Penny Kelly, are worthwhile choices.