I suspect they do.
What makes an animal intelligent? – Its brain.
How does the brain work? – It forms a complex network of neurones that fire as with a computer.
How do the nerve cells fire? – They have electrochemical charges on their membranes. They change electric potential by moving charged ions.
Do plants think? – We don’t know. We know they are conscious of their environment and respond to it.
How would a plant think? It doesn’t have a brain or nervous system does it? – All plant cells have the same electro-potential as brain cells. Maybe the whole plant operates as a brain?