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 crossbill was in a coevolutionary arms race with the lodgepole pine, further leading to habitat isolation. In 2016, it was identified as phylogenetically distinct from the other call types. This is an example of sympatric speciation. In 2017, the AOU reached a consensus and split the South Hills crossbill from the red crossbill and rename it the Cassia crossbill, because its habitat resided in Cassia County, Idaho. The Cassia crossbill will exclusively forage for lodgepole pine cones that are found in the South Hills and Albion Mountains region. A primary reason why this species of crossbill can exist in such