What spice is also known as Chinese cinnamon?

It comes from the bark of a relative of Ceylon cinnamon (Cinnamomum verum) and is called cassia (Cinnamomun cassia). The Chinese version is more pungent and a preferred flavor by many to the Ceylon cinnamon. Cassia makes up one of the five spices traditional in Chinese cuisine with the others being fennel, cloves, star anise, and Sichuan pepper. Yum! In the USA cinnamon is usually not marked as either true Ceylon cinnamon or cassia. The volatile cassia oil is the aromatic part of the bark that gives it the distinct spicy flavor. Remarkably cassia oil only makes up about 1 to 2% of the total volume of the spice.

https://www.britannica.com/topic/cassia-spice