It would seem that humans have smoked everything you can possibly smoke, as well as plenty of things you can't or shouldn't.
Gately's History of Tobacco book notes that during the Vietnam War, enemy combatants hard-up for capital or access to tobacco would smoke whatever plants they could find, just because warriors tend to love the act and calming nature in the act of smoking.
Back in my stoner days I decided I'd smoke all kinds of herbs. I've smoked spearmint (particularly pleasant and cool but I can't speak with any confidence to its safety), lemongrass, lemon balm, lavender, and all sorts of other shit. They say you can smoke basil - it's dried in the same manner as tobacco, even - and if that's true, then reason might dictate that you can smoke sage, thyme, cilantro, and maybe even rosemary too.
Deertongue - noted for its vanilla-like reminiscence in a few C&D blends - is a wild weed here in Carolina. And so, 10,000+ years ago in South America, was tobacco. It was just a grass.
All that to say... next time I shuck an ear of corn, I'm not gonna throw away the husk. I'm'a see what all the fuss is about. Maybe I'll even ignite it in my corn cob pipe, just for my own amusement of vegetabolic fratercide.
