This is flower with all its parts labeled:
and this a female vagina with all its parts labeled:
What do these two have in common? They are both genital organs.
So when one receives flowers, the one who gives is saying 'Here are some severed flower genitals because I was thinking of seeing yours'.
Speaking of flowers, florist shops should be called Plant Funeral Parlors, because once flowers are removed from the soil, they are dying, like fish removed from water. They are not alive, and putting them in water only adds to their life span for so long. They're pretty much dead. So people are giving dead plant genitals to other people as a gesture of love because...why? Because they are pretty? Or because society dictates that it's okay to give dead things to each other as a gesture of romance?
Just know this, if someone gives me a plant, I better be able to eat it, otherwise, just don't bother. Thank you and enjoy your upcoming Catholic Saint's Day.