Herbal teas, a wonderful way to explore the world of brewing botanicals. There are many beverages that are referred to as "tea," but technically if it's not Camellia sinensis (i.e. black, green, etc.) it's actually an "infusion" or "tisane".
P.S. All the below tisanes are naturally caffeine-free except for the highly caffeinated Yerba Mate (great as a coffee replacement).