Calycanthus

A 2006 molecular phylogenetic study of the family Calycanthaceae found that the three widely recognized species of Calycanthus formed a monophyletic group. Relationships among the three species differed depending on whether chloroplast or nuclear data was used. A cladogram obtained by combining the two is shown below.[11]

The family Calycanthaceae may have had a Gondwanan origin. The sole Australian representative, Idiospermum australiense, would then represent an ancient relic, probably having diverged in the Cretaceous. There are no extant South American members of the family, although fossils are known. Calycanthus may have migrated into North America from eastern Asia, or may have originated in South America, moved northwards and then spread to eastern Asia.[11]

As of February 2020, Plants of the World Online accepted four species:[12]

• Calycanthus brockianus Ferry & Ferry f.—north central Georgia; has greenish rather than brownish red flowers, and may only be a triploid color variant of C. floridus.[6]
• Calycanthus chinensis (W.C.Cheng & S.Y.Chang) W.C.Cheng & S.Y.Chang ex P.T.Li (syn. Sinocalycanthus sinensis)—Chinese sweetshrub, Chinese wax shrub, native to eastern China, with white flowers[13]
• Calycanthus floridus L.—Carolina spicebush, eastern sweetshrub, native to the Eastern United States, from New York and Missouri, south through the Appalachian Mountains, Piedmont, and Mississippi Valley, to Louisiana, and east to northern Florida[14]
  • C. f. var. floridus (syn. C. mohrii)—eastern sweetshrub; twigs pubescent (hairy)[15]
  • C. f. var. glaucus (syn. C. fertilis)—eastern sweetshrub; twigs glabrous (smooth).[16]
• Calycanthus occidentalis Hook. & Arn.—California spicebush, western sweetshrub, native to moist habitats of California below 1,500 m (4,900 ft), including in the California Coast Ranges, San Joaquin Valley, and Sierra Nevada.[17][18] The Oregon Flora Project documents one specimen in Oregon.[19]

C. chinensis has a confused taxonomic history. It was first described in 1963 as Calycanthus chinensis by W.C. Cheng and S.Y. Chang, but invalidly because two different collections were both given as holotypes. The authors then described it validly in 1964 in their new genus Sinocalycanthus. In 1979, P.T. Li rejected the genus Sinocalycanthus, and validated the original name Calycanthus chinensis.[6]

• 
  C. chinensis–Chinese sweetshrub
• 
  C. floridus—eastern sweetshrub
• 
  C. occidentalis—western sweetshrub
• 
  C. occidentalis—western sweetshrub

Calycanthus floridus and C. occidentalis were both used as a traditional medicinal plant by Native Americans. The indigenous peoples of California also used C. occidentalis in basketweaving and for arrow shafts.[20] [21]

Calycanthus species are cultivated as ornamental plants by plant nurseries, including in the United States and England.

Calycanthus occidentalis is planted in traditional, native plant, and wildlife gardens, and for natural landscaping and habitat restoration projects, primarily in California and the Western United States.[5][7][22][23] It was introduced into cultivation in 1831.[5]

Calycanthus floridus is also planted in gardens, as a specimen shrub, or for hedges.[24][25] The cultivar C. × raulstonii 'Hartlage Wine' has gained the Royal Horticultural Society's Award of Garden Merit.[26]

Mark Catesby found it in the Piedmont woodlands of the British Province of Carolina in 1732. He described it, with its bark "as odoriferous as cinnamon", but did not name it.[27] The colonial planters of the Carolinas transplanted it into their gardens, and the botanist Peter Collinson described it to Linnaeus and imported it into England from Charleston in the Province of South Carolina around 1756.[28]

Calycanthus × raulstonii 'Hartlage Wine'

Several hybrids and cultivars have been produced. The hybrid between C. chinesis and C. floridus has been named C. × raulstonii. It combines the larger flowers of C. chinesis with the flower color of C. floridus. The original cross has been given the cultivar name 'Hartlage Wine' after the student, Richard Hartlage, who made the first crosses. Further crosses have been made. 'Venus' involves C. occidentalis as well.[6]

Calycanthus oil, distilled from the flowers, is an essential oil used in some quality perfumes.[29] The flowers of C. occidentalis have a spicy, sweet scent. The flowers of C. floridus were compared to a bubble-gum scent by one reference.[30]