Usually found in tropical regions such as Brazil, Costa Rica, Venezuela, Panama, Colombia, Guyana, Argentina and Peru, Quassia is a flowering shrub. Its bark is decocted and used for creating various tinctures and extracts. Moreover, it is a key ingredient in various herbal bitters.
The species name for Quassia, which is amara is derived from the Spanish word “amargo” meaning bitter. This is an ideal name considering the bark contains a substance known as quassin, which is fifty times more bitter than quinine. As a matter of fact, quassin is the most bitter naturally-occurring chemical in the world. As mentioned before, the bark of Quassia is used to make herbal bitters, and it is only because of the presence of quassin that it is so effective in its role. While it is a common herbal bitter ingredient in moderate amounts, quassia in higher amounts can be a highly effective natural insecticide when mixed with other substances.

Quassia also has tons of health benefits, thanks to its bitterness. For instance, it can help improve digestion and provide relief from diarrhea. Moreover, quassia is great for people who need to increase their appetite as it can increase saliva and stomach acid production.