Gui Zhi

Cinnamomum cassia is an evergreen tree in the Lauraceae, native to southern China and widely cultivated across South and Southeast Asia. Mature trees reach 10-15 m tall with a stout trunk, smooth grey to reddish-brown bark, and a dense rounded crown. The leathery, oblong-lanceolate leaves are 8-20 cm long, glossy dark green above and glaucous below, with three prominent longitudinal veins arising near the base. Small, pale yellow to greenish flowers are borne in axillary or terminal panicles in summer, followed by ovoid, dark purple to black drupes about 1 cm long, each seated in a shallow cupule. Both the bark and the slender young twigs are strongly aromatic, yielding a sweet, pungent volatile oil rich in cinnamaldehyde. The species favours moist, well-drained soils in subtropical lowland and montane forests and is grown commercially in plantations in China, Vietnam, Indonesia and elsewhere.