Since plants are rooted to their spots, they have highly sophisticated systems of sensations, food gathering, and protection. Plants exhibit fifteen to twenty specific senses beyond our simple five. From root to leaf, they respond to chemicals, light, gravity, moisture, touch and other environmental stimuli, even collectively responding, communicating, and sharing resources. Plants can change their molecules to disarm threats, can emit chemicals to repel predators and attract allies.
Some plant scientists maintain “no brain; no intelligence, no abstract thought, judgment, or reason.” In contrast, Social scientists, philosophers, and psychologists lean toward a definition of intelligence as the ability to respond in optimal ways to challenges presented by changeable circumstances. 
Scientists that advocate for plant intelligence belong to an emerging group called neurobiologists. Stefano Mancuso claims that plants show intelligence by their incredible problem-solving capabilities.  At the cell level, plants exchange information and network with one another, gathering and integrating environmental data. With some form of memory they store information and use it to adapt to changing circumstances. Neurobiologists call this consciousness of one’s surroundings “being online”, as opposed to the old paradigm of consciousness as being an inward awareness of one’s existence, and the perspective of “no brain = no pain.” If plants adapt to challenges, as they do, then they must be responding to signals of pain or discomfort. Perhaps this belongs to the broader network of nature’s intelligent handling of environmental imbalance. 
Recent findings by Suzanne Simard describe how an underground plant network between trees in a “wood-wide web” employ fungal connections among their roots to wisely share information, water, and nutrients for survival. This is an example of self-management analogous to the biological intelligence currently being discovered within the cellular and molecular systems in the bodies of higher life forms like ourselves.
If we can emulate how plants integrate themselves with their environment, it will help us human beings better evolve. The emerging message is that, rather than being based on competition, the systems and communities of nature employ far more cooperative behavior than previously thought. If we become extinct, the plant kingdom will survive; the opposite will not come about. We have a lot to learn from the other ninety-nine percent of biomass on this planet. Exploring nature will surely awaken innovative insights and advancements in human understanding and sustainability.
Michael Pollan, The Intelligent Plant, New Yorker Magazine, 12/23/13 page 92
Ibid page 94
Ibid page 95
Ibid page 95Ibid page 102