Calycanthus chinensis
Calycanthus chinensis, known as Chinese sweetshrub, is a species of flowering plant in the family Calycanthaceae, native to Southeast China. It was first given a valid scientific name in 1964. It is cultivated as an ornamental flowering shrub, and has been hybridized with two other species in the genus Calycanthus to combine its larger and broader tepalled flowers with their scented and more colourful ones.
It has been treated as the only species in the genus Sinocalycanthus.
Description
Calycanthus chinensis is a deciduous shrub or small tree up to high and the same across. Older twigs are hairless and have greyish or greyish-brown bark. The leaves are aromatic and arranged in an opposite fashion. The leaf petiole is about long. The leaf blade is variable in shape but broadly ovate, long by wide. The base of the leaf petiole hides the lateral buds.In its original habitat in China, it flowers in May. The nodding flowers are terminal, about across, and borne singly on a short pedicel long. There is no clear distinction into sepals and petals. There are about 10–14 white outer tepals, often flushed pink, especially as they age, and about 7–16 yellowish inner tepals, with purple marks near the base. The inner tepals are shorter and thicker than the outer ones, and curve inwards. The fruit matures in October in the wild. It is ovoid, with a spiral of marks at the top showing the former position of the tepals. The seeds are achenes, about long, and have silky hairs.
Taxonomy
Calycanthus chinensis has a somewhat confused taxonomic history. It was first described in 1963 as Calycanthus chinensis by W.C. Cheng and S.Y. Chang. However, their use of the name was invalid under the International Code of Nomenclature for algae, fungi, and plants, 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.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: C. chinensis was either sister to C. floridus plus C. occidentalis, or formed a clade with C. occidentalis, C. floridus being sister to both.