As shown in the images below, people in the Middle Ages thought plants had abilities that paralleled those of humans and animals. WSU psychologist Jay Wright says the idea of plant intelligence is intriguing, but it's not new. "It's cyclical," he says, citing a flush of "smart plant" research in the 1920s and again in the 50s and 60s. Those efforts sputtered out for lack of solid evidence. New research into how plants communicate and manage their environment puts the notion on more solid footing today. Images are from the Italian Herbal, Special Collections, University of Vermont Library.

