Cinnamomum cassia United Kingdom, and India is Chinese cinnamon. "Indonesian cinnamon" ("C. burmannii") is sold in much smaller amounts. Chinese cassia is produced in both China and Vietnam. Until the 1960s, Vietnam was the world's most important producer of Saigon cinnamon, which has a higher oil content , and consequently has a stronger flavor. Because of the disruption caused by the Vietnam War, however, production of Indonesian cassia in the highlands of the Indonesia island of Sumatra was increased to meet demand. Indonesian cassia has the lowest oil content of the three types of cassia, so commands the lowest price. Chinese cassia
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