Cactus roots at high magnification
Plants are active communicators capable of warning nearby plants of an impending insect infestation when they themselves are being eaten alive. They can also execute surprisingly sophisticated interpretations of their surroundings. Plants can compute their survival chances with a cost-benefit analysis of available resources. They can distinguish between positive and negative experiences and are even capable of forming memories from stressful events. They can recognize self vs. non-self, taking over territory from plants they deem weaker. As plants rapidly exchange chemicals and genetic material with other species, they constantly update their own behavior to better compete for light and food in order to survive.
Image by Matt Sharp.