That's because there are two spices commonly referred to as cinnamon: Ceylon cinnamon and cassia. True cinnamon, or Ceylon cinnamon, is rarer and quite costly, whereas cassia is readily available ...

or "true" cinnamon, goes by the scientific name of Cinnamomum verum and is grown mostly in Sri Lanka. In the United States, the most commonly sold type is cassia cinnamon or, formally, Cinnamomum ...