Surely once insects have brought pollen to a flower, then plant-plant interaction is over? Not so, says Gerardo Arceo-Gómez, who argues that heterospecific (or other plants') pollen arriving in a flower might affect plant diversity.
You can read this at https://www.botany.one/2021/10/what-happens-when-pollinators-bring-the-wrong-pollen/
You can read the original paper at: https://doi.org/10.1093/aob/mcab082