A close relative of the Cinnamon zeylanicum tree, Cassia has a thicker bark exterior forming a strong layered quill compared to cinnamon bark, and contains a higher percentage of essential oil yield per weight. Cassia can often be found labled as cinnamon bark in spice markets due to consumer preferences. Cassia essential oil has a strong, spicy cinnamon aroma and can be found growing in many regions around the world including China, Vietnam and Indonesia with global production running year round for the spice markets.