PLANT SUCCESS: The consequence of the hysteretic responses of leaves to ambient water vapor, carbon dioxide, light intensity, and temperature

Plants account for the vast majority of the biomass on land. They first appear in the fossil record many millions of years ago. Some researchers have proposed that the obvious success of plant-life indicates that plants are “intelligent.” Plant intelligence has been strongly challenged, however, because plants do not possess brain-like tissues similar to electrical neurons, axons, and synapses. The following paper argues that a plant leaf is more properly understood as being a kind of analog computer called a “crossbar array.” The leaf’s computational facility arises from how leaf stomata respond to environmental water vapor, light, carbon dioxide, and heat. Though counterintuitive, a leaf’s success is enhanced by the phenomenon of “stomatal oscillations.”