That makes sense at first glance, but it’s not true when you think about it for a bit. People have allergic reactto grasses and trees that broadcast spawn their pollen all over the place. Bees collect nectar from flowering plants and spread pollen around that way. Plants only choose one over the other since they are both very resource intensive mating strategies. No one is allergic to lillac, but plenty of people are allergic to ragweed.