Cassia is the dried husk (bark) of a small, bushy evergreen tree. Though botanically has close relations, cassia is considered inferior to cinnamon. There are different varieties of cassia, obtained from different species of Cinnamomum and originating from different sources. These include 'Chinese', 'Indonesian', 'Saigon', 'Vietnamese' and 'Indian'.

Though there is a generic likeness in the aromatic properties of the various species of cassia, they do exhibit differences in some respects. Cassia bark is a popular ingredient in foods, beverages, perfumery, toileteries and cosmetics, while the oil of cassia finds extensive application in liquors and beauty products. Cassia is often used as a less costly substitute to true cinnamon.