Posting here as well because I think I did so in the wrong place the first time. Apologies, new to wiki-ing in the modern era.
I might be crazy, but I'm pretty sure Flower Man has the ASGORE motif-- specifically, the first part of Bergentruckung.
Someone better at music theory should confirm this, but I think that the "Flower Man, Flower Man / With his heart in the sand" part of the song is just the first half of Bergentruckung with a different tempo. I'm 90% sure it's the same notes. Can someone who knows more about this sort of thing listen and confirm/deny?