There's evidence for stunningly intricate, marvelously impressive biological function, but there's no evidence whatsoever for internal mental states.
replyWhat's happening is we borrow from a pre-existing vocabulary with connotations to conscious activity and we use it to describe automatic biological reflexes, and then some people lose track of whether it was an analogy or whether it was literal and start claiming plants can "feel."
It's funny you bring up "have no mental state", because there is a plant that scientists find seems to have some sort of memory:
replyhttps://www.sci.news/biology/science-mimosa-plants-memory-01...
> The scientists show how Mimosa plants stopped closing their leaves when they learnt that the repeated disturbance had no real damaging consequence.
...
> Astonishingly, Mimosa can display the learned response even when left undisturbed in a more favorable environment for a month.