The May Queen aspect was Gaiman's concept, expanding Alan Moore's concepts of the Green (the world's plantlife having a connected consciousness) from Swamp Thing, to DC's other plant based characters like Black Orchid and, of course, Ivy. It was Rucha that really took it and ran with it, though. Rucha's take on the character is my favorite.
I do love it, of course. I've always been interested in how classic mythic archetypes recur in modern Myths, like superhero comics. That may be why I've always found the Big Three of Superman, Batman, and Wonder Woman more fascinating than, say, the Flash (Not that I don't like Wally, mind you). It's also, I strongly suspect, part of the reasons those became the Big Three.