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 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.