http://www.rtve.es/tve/b/redes/seman...398/index.html

Check that link out, its in Spanish though. It briefly explains a segment of a weekly scientific TV show called Redes from Television Espanola. In this episode they approach a subject much similar to this thread, its about instinctual interactions that plants carry out with their surroundings. This instinct is the basic instinct of all life form, survival.