Cinnamomum cassia elongated leaves that are long and have a decidedly reddish colour when young. Chinese cassia is a close relative to Ceylon cinnamon ("C. verum"), Saigon cinnamon ("C. loureiroi"), also known as "Vietnamese cinnamon", Indonesian cinnamon ("C. burmannii"), also called "korintje", and Malabar cinnamon ("C. citriodorum") from Sri Lanka. In all five species, the dried bark is used as a spice. Chinese cassia's flavour is less delicate than that of Ceylon cinnamon. Its bark is thicker, more difficult to crush, and has a rougher texture than that of Ceylon cinnamon. Most of the spice sold as cinnamon in the United States,
Cassia crossbill mentioned previously, the red crossbill had 10 different call types and the Cassia crossbill was call type 9. The Cassia Crossbill fledgling initially imitates its parents’ flight calls and eventually will modify its call to imitate their mate. Compared to the other call types, the Cassia crossbills songs will be more repetitive while using fewer syllables. The individual notes of the song are typically buzzier and will have multiple instances of silence in between call phrases. Their song consists of strained and sharp "chip" and "kip" calls. Occasionally when red crossbills forage, there will be overlap between different call types.