This tiny interaction I think is the the entire problem with how panpsychists talk about this.
Some panpsychists might try to actually say that there's a potential that trees and rocks have an internal subjective experience that is in some way comparable to human conscious experience (i.e. they feel some kind of "pain," that "hurts" them, and they "suffer". But I contend we have very little reason to believe that, and a lot of reason not to believe that. For example, with very, very little modification to my biology, I can eliminate this experience in myself (painkillers, anesthesia, other drugs, falling into a deep sleep, etc.)
Once you even slightly disrupt the structure of our brains functioning, it all falls apart. We feel nothing.
I think even most panpsychists would not take the above position, and would instead say "oh well, plant consciousness is entirely unrecognizable and might not even have reasonable continuity of consciousnesses. "Pain" wouldn't even make sense to a plant or a rock. We're just saying that the matter that constitutes plants and rocks have a very tiny (relative to humans) kind of "experience" but it's a huge mistake to anthropomorphize that, and you shouldn't feel like you're making grass "suffer" by cutting it.
^and if it's the second case, it's unprovable and uninteresting and "literally meaningless. Irrelevant."