The Calycanthaceae (sweetshrubs or spicebushes) are a small family of flowering plants in the order Laurales. The family contains three genera and only 10 known species (Christenhusz & Byng 2016 ), restricted to warm temperate and tropical regions:
- Calycanthus (three species; western and southeastern North America and one species in eastern Asia)
- Chimonanthus (six species; eastern Asia)
- Idiospermum (one species; Queensland, Australia)
They are aromatic, deciduous shrubs growing to 2–4 m tall, except for Idiospermum, which is a large evergreen tree. The flowers are white to red, with spirally arranged tepals. DNA-based phylogenies indicate the Northern Hemisphere Calycanthus and Chimonanthus diverged from each other in the mid-Miocene, while the Australian Idiospermum had already diverged by the Upper Cretaceous and likely represents a remnant of a former Gondwanan distribution of Calycanthaceae that included South America, as indicated by the occurrence of Cretaceous Calycanthaceae fossils in Brazil.
- Angiosperm Phylogeny Group (2009). "An update of the Angiosperm Phylogeny Group classification for the orders and families of flowering plants: APG III". Botanical Journal of the Linnean Society. 161 (2): 105–121. doi:10.1111/j.1095-8339.2009.00996.x.
- Christenhusz, M. J. M.; Byng, J. W. (2016). "The number of known plants species in the world and its annual increase". Phytotaxa. Magnolia Press. 261 (3): 201–217. doi:10.11646/phytotaxa.261.3.1.