It is hard to tell them apart once they have been ground. But there are differences in the appearance, aroma, and flavors of these two cinnamons. Cassia comes from China’s “Cinnamomum cassia” tree. It is a darker brown hollow tube that is harder and thicker than the thin and solid cigar-like shape of Ceylon. The aroma of the Cassia is more robust, but the flavor is not. The Ceylon’s pleasant aroma is both delicate and sweet, along with the taste.