CASSIA
Cassia has a warm, spicy character closely associated with cinnamon, often carrying a sweet edge. Its oil is rich in cinnamaldehyde, an aromatic component that helps explain this recognisable cinnamon impression. In a perfume, that spice can be the feature to look for, whether the surrounding composition makes it feel sweeter or more restrained.
The material discussed here is Cinnamomum cassia, also known as Chinese cinnamon. Cassia oils are not all bark oils: leaves and twigs are commonly steam-distilled, while bark oil is also produced. A documented Vietnamese grade, for example, comes from branches. The name alone therefore does not establish the plant part, origin or exact composition of an oil, nor prove that natural cassia is present in every perfume listing the note.