Cassia is closely related to cinnamon, and is often used as a substitute. The tree can grow up to 17 metres, with greyish bark and hard, elongated leaves approximately 10 – 15 centimetres long with a decidedly reddish colour. To harvest cassia spice trees are cut down at the age of 6 years, in order to harvest their branches for their yield of bark. The bark is then flattened, its epidermis removed and dried for 24 hours to create the aromatic cassia spice. The spice is distinguished from cinnamon as it is much harder, made from only one thick layer in comparison to the multiple thin layers and relative softness of cinnamon sticks. Cassia buds, although rare, are also occasionally used as a spice. They resemble cloves in appearance and have a mild, flowery cinnamon flavor. Cassia buds are primarily used in old-fashioned pickling recipes, marinades, and teas.