The genus includes two to four species depending on taxonomic interpretation; three are accepted by most 21st century sources.

[3][4][5][6] The flowers are typical of the family Calycanthaceae in lacking distinct sepals and petals, but instead having spirals of tepals.

[8] The flowers of the two North American species are scented, 4–7 cm (1.6–2.8 in) across, with numerous dark red to burgundy to purplish brown tepals.

C. chinensis has broader tepals, the outer ones white flushed with pink, the inner ones mostly yellow with purple marks at the base.

[10] C. occidentalis has been shown to produce chemicals that mimic fermenting fruits that attract beetles in the families Nitidulidae and Staphylinidae.

[14] A 2006 molecular phylogenetic study of the family Calycanthaceae found that the three widely recognized species of Calycanthus formed a monophyletic group.

[10] As of February 2020[update], Plants of the World Online accepted four species:[1] C. chinensis has a confused taxonomic history.

[22][23] The English naturalist Mark Catesby drew it as the support for the bird he called "Garrulus Carolinensis The Chatterer" (now Bombycilla cedrorum) in a work published from 1731 onwards.

[5][7] Hybrid cultivars include:[7] Calycanthus floridus and C. occidentalis were both used as a traditional medicinal plant by Native Americans.