Eating a rare flower will aggrow any dino around you, passive or aggressive. this could sometimes be a really bad idea. You could however, use it to tame skittish Dinos like a tapejara or a quetzal. Because eating it will cause them to not run away while you knock them out.
Same thing as the mushroom on mobile, they don't have their special effect... Mushrooms do not cause vision to blur and flowers do not aggro anything. (Which makes them a wonderful food source! So light and easy to carry! No health regen tho, shame)