Flowers are Romantic . . .
Seriously though, Flowers have a certain symbolic magic because our culture invests them with romantic mystery. Like your engagement ring . . . I could get you an engagement necklace with 10 carats worth of high cut diamonds surrounded by other prescious gems in a personally dignificant arrangement. . . but what girl would want that in lieu of a ring? Why? Because our culture invests certain items with magic.
I could send you a pretty block of wood instead of flowers . . . but its just not the same. Plus, lets face it, its an effort for us guys to be creatively romantic, so it takes some of the pressure off of us if we know what to get you for certain occasions
Just an observation, but hey, what do I know . . .