Cassia Buds are the unopened flowers of the cassia (cinnamon) tree that are picked just before blooming and dried in the sun.
Cassia buds look like small cloves. The picking has to be timed perfectly, therefore the quality can vary greatly from crop to crop. Their flavor is close to cinnamon but with more of a floral, winey scent. They are commonly used for pickling and mulling spice blends.