Bison grass vodka
Bison grass (Hierochloe odorata) is a perennial grass native to North America and northern Europe. Typically harvested in mid to late summer (before the first frost), bison grass has been used for centuries by the church in Europe and native American populations, who used it as a form of incense.
The sweet-vanilla aroma of bison grass comes from coumarin, which is also found in tonka beans, woodruff and cassia cinnamon. Coumarin is moderately toxic to the liver and kidneys, but is also an anticoagulant.
In Poland, bison grass is used to flavor vodka (called Zubrowka), which is now imported in a coumarin-free form into the United States.