Most of what we enjoy and call cinnamon in the U.S. is Cinnamomum aromaticum or C. loureiroi, also known as cassia. It's the brash, bold, sweet-and-spicy stuff we love in our cinnamon buns and gingerbread. But it's not the only cinnamon out there. In the past, when people talked about cinnamon, they were talking about C. verum (née C. zeylanicum when Sri Lanka was called Ceylon). It's not the cinnamon Americans are used to—it's much more mellow and subtle—but it's worth expanding our horizons for.