I didn't know they throw out flowers underwater! They're very pretty, too, like miniature Calla lillies:
You can do a weak bleach dip to rid the BBA. Make sure to dechlor well. Also, putting the plant emersed will help rid the algae.Only seen mine pearl once.. it probably doesn't help that I can't get the BBA off of it to save my life.
When I first put it in the tank it did shoot off flowers like crazy though, not so much anymore.