''Calycanthus chinensis'', known as Chinese sweetshrub, is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...

in the family

Calycanthaceae 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 , restricted to warm temperate and tropical regions: * '' Calycanthus'' (thr ...

, native to

Southeast China The points of the compass are a set of horizontal, radially arrayed compass directions (or azimuths) used in navigation and cartography. A compass rose is primarily composed of four cardinal directions—north, east, south, and west—each se ...

. 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 ''Calycanthus'', called sweetshrub, is a genus of flowering plants in the family Calycanthaceae. The genus includes two to four species depending on taxonomic interpretation; three are accepted by most 21st century sources. Description ''Calyca ...

'' to combine its larger and broader

tepal A tepal is one of the outer parts of a flower (collectively the perianth). The term is used when these parts cannot easily be classified as either sepals or petals. This may be because the parts of the perianth are undifferentiated (i.e. of very ...

led 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 (stalk) 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 Pedicle or pedicel may refer to: Human anatomy *Pedicle of vertebral arch, the segment between the transverse process and the vertebral body, and is often used as a radiographic marker and entry point in vertebroplasty and kyphoplasty procedures ...

long. There is no clear distinction into

sepal A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coine ...

s and petals. There are about 10–14 white outer

s, 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. Calycanthus chinensis 2020-06-23 9521.jpg, Habit in cultivation in Poland Calycanthus chinensis 2020-06-23 9527.jpg, Leaf Sinocalycanthus chinensis 2017-06-25 3042.jpg, White flower Calycanthus chinensis 2020-06-23 9533.jpg, Pink-tinged flower Calycanthus chinensis kz1.jpg, Fruit showing tepal scars

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

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of sever ...

s. (Article 9.1 requires the holotype to be only one specimen.) 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'' (inadvertently according to the

International Plant Names Index The International Plant Names Index (IPNI) describes itself as "a database of the names and associated basic bibliographical details of seed plants, ferns and lycophytes." Coverage of plant names is best at the rank of species and genus. It inclu ...

). A 2006 molecular phylogenetic study of the family

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.

Distribution and habitat

''Calycanthus chinensis'' is known from Zhejiang Province in southeastern China, where it is found at elevations of in woods, particularly along streams.

Cultivation

''Calycanthus chinensis'' is cultivated as an ornamental shrub. In the United States, it is usually considered hardy in

zones Zone or The Zone may refer to: Places Climate and altitude zones * Death zone (originally the lethal zone), altitudes above a certain point where the amount of oxygen is insufficient to sustain human life for an extended time span * Frigid zone, ...

6–8. In Europe, it is hardy as far north as eastern Scotland. Well-drained but moist, acid soils are recommended. In cooler climates, full sun is recommended, and it will have a long flowering season, beginning in June in southern England. In warmer climates in the US, it will grow in some shade and has a shorter but earlier flowering season, beginning in April. It can be propagated by softwood cuttings in summer, or by seed.

Hybridization

Calycanthus raulstonii 'Hartlage Wine', Morris Arboretum 01

''Calycanthus chinensis'' has been hybridized with the two North American species of ''Calycanthus'', the aim being to combine the larger flowers of ''C. chinensis'' with the colour and fragrance of those of ''C. floridus'' and ''C. occidentalis''. The North American species are also hardier. The first cross, made in 1991 by Richard Hartlage at North Carolina State University, was between ''C. chinesis'' and ''C. floridus''. The hybrid has been given the scientific name ''C.'' × ''raulstonii'', with the original cross treated as the

cultivar A cultivar is a type of cultivated plant that people have selected for desired traits and when propagated retain those traits. Methods used to propagate cultivars include: division, root and stem cuttings, offsets, grafting, tissue culture ...

'Hartlage Wine'. Further crosses have been made. 'Venus' also involves ''C. occidentalis''.

References

{{taxonbar, from1=Q11739000, from2=Q50870612 Calycanthaceae Flora of Southeast China Plants described in 1964