Thanks for running this giveaway!
My favorite flower would probably have to be the
rafflesia. Might be considered an odd choice, but...
leaf me alone! I've just thought they were pretty neat since I learned about them as a kid and then saw it represented by the Pok?mon Vileplume, which I am also fond of. If they weren't considered a punishment for a poorly run town, and if they weren't limited to just one rafflesia, I would want to grow multiple of them in an Animal Crossing town for the aesthetic purposes.
Runner-up would probably be aconitum, which goes by many names, but the one I associate it with the most is wolf's-bane. I grew to like it because of the poem from the 1941 movie The Wolf Man: Even a man who is pure in heart and says his prayers by night, may become a wolf when the wolf-bane blooms and the autumn moon is bright. There are apparently different colors, but I'm also fond of what appears to be the typical purple variation.