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.
A great way to farm these sometimes hard to find flowers go to swamps.Now if you have a Theri you can spam tickle to any swamp plant to get X or Y seeds idk I forgot.Especially you can get huge amounts of rare flower.I hope this was useful.
If you eat a rare flower near wild dinos, they will become aggressive towards you for a period of time, as well as anything you meet along the way. Avoid doing so unintentionally, however this can become useful if you need to grab a dinos attention for taming or to lead it somewhere.