Native plants will always reward you. It only makes sense that if they are native to your area then they obviously like to grow there. I'd give you some resources but I'm about ready for a nap. But wait! Check out the Ok Native plant Society.
http://www.oknativeplants.org
And if you want to cut to the chase, then that site has this:
http://www.oknativeplants.org/...
As you're surfing around in general or paying attention to some nice plants recommended here,
if you see something you like, then there are some databases (not just here) that will tell you native or non-native. And watch out for anything that's indicated as invasive.
I have no idea what ferns might be native to OK, but I can tell you some by their common names. (sorry, not that helpful. best to know the botanical names.)
I love Autumn ferns because they are evergreen here in Zone 8a and because their new growth always has a coppery color that does eventually turn green. Oh, let me think about it and will post again later.
I'm glad that you read about the root flares. Aborilogical Services has an excellent reputation.
