Wild dryad tree sex was pretty much where my Narnia head cannon began after a discussion with my landscaper about male hollies and a really bad tree pollen season. It's s always been in my Narnia stories. In my first Narnia-set story, all the Trees are indiscriminately pollinating and Edmund develops a tree pollen allergy so he's the only who isn't getting spring sex with the Dryads -- the bark being something for which there are workarounds I do not elaborate upon! And then I elaborated more on the Dryad Dance and rituals in a story for the Narnia Fic Exchange a few years later.