User blog comment:PerhapsTheOtherOne/All About That Stuff People & Animals Apparently Have/@comment-3146930-20140809144345/@comment-3146930-20140809170834

I actually had an idea based around this some time ago. Pyrrha only mentions people and animals have an Aura, but doesn't say anything about plants. This however does bring up an interesting idea, especially when looking at the opening narration. It may be possible that the planet itself is alive in some way and feels the state of the world. If the Grimm existed before humans as the narration implies, then the planet could have made people, animals, and plants as a way to balance the world and blessed them with the power to use Aura and Semblance.

I'm not saying that there is a big brain in the middle of the planet, but if the planet is alive in some way, it could be influencing the world on a scale that people don't understand. The plants of the world could just be the result of the planet trying to make life. Living planets is something that pops up a lot in various forms of media after all.