Calycanthus

Calycanthus, a small genus of North American shrubs often seen in English gardens and forming the type of the order Calycanthaceae. They have opposite entire leaves and purple or chocolate flowers in which the indefinite narrow sepals and petals and the stamens are arranged in a continuous spiral. C. floridus is known as Carolina Allspice, and C. occidentalis is a native of Carolina. The aromatic bark of the former is used as a tonic in America.