A popular spice, cinnamon (canel in Middle English) is the bark of several species of trees in genus Cinnamomum, such as C. zeylanicum and C. aromaticum (cassia). There is a long history of confusion between the different species of this genus, and in some places the word cinnamon refers exclusively to C. zeylanicum, though in North America the word is more often applied to cassia.
It is available as dried and rolled strips of bark, known as quills, or as a powder made from the bark. Cassia buds are also sometimes used in cookery. It appears in 13th century cookbooks, and is a popular ingredient for metheglin.
Cinnamon quills can be distinguished from the similar cassia by thickness - cassia quills tend to be round, thick and smooth, whereas cinnamon quills are thin and papery.
In Middle English, the term canel is used for cinnamon. It is not usually clear which species it refers to, and occasionally there seems to be a distinction between the two words, as in a note to Curye on Inglysch Part II no. 19, which says, "poudre of sinamome or of canel".