There is a kind of brain chauvinism. We think that a brain is something that is absolutely needed to have intelligence. Not so...
[Darwin] was right...If we need to find an integrative processing part of the plant, we need to look at the roots.— Stefano Mancuso quoted in Root intelligence: Plants can think, feel and learn, an article by Anil Ananthaswamy who also quotes Michael Marder:
Our task is to think about... concepts of attention, consciousness and intelligence in a way that becomes somehow decoupled from the figure of the human. I want [us] to rethink the concept of intelligence in such a way that human intelligence, plant intelligence and animal intelligence are different sub-species of [a] broader concept.See also these posts from the blog of Barely Imagined Beings, The Intelligent Plant by Michael Pollan and The Mental Life of Plants and Worms... by Oliver Sacks