''Cercidiphyllum'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

containing two

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of plants, both commonly called katsura. They are the sole members of the

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unisp ...

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Cercidiphyllaceae. The genus is

native Native may refer to: People * '' Jus sanguinis'', nationality by blood * '' Jus soli'', nationality by location of birth * Indigenous peoples, peoples with a set of specific rights based on their historical ties to a particular territory ** Nat ...

to Japan and China and unrelated to ''

Cercis ''Cercis'' is a genus of about 10 species in the subfamily Cercidoideae of the pea family (biology), family Fabaceae. It contains small deciduous trees or large shrubs commonly known as redbuds in the USA. They are characterised by simple, rou ...

'' (redbuds).

Description

The

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

, ''

Cercidiphyllum japonicum ''Cercidiphyllum japonicum'', known as the Katsura (from its Japanese name カツラ, 桂), is a species of flowering tree in the family Cercidiphyllaceae native to China and Japan. It is sometimes called ''caramel tree'' for the light caramel sm ...

'', can reach in height, and is one of the largest hardwoods in Asia. The other species, '' Cercidiphyllum magnificum'', is much smaller, rarely reaching over in height. ''Cercidiphyllum'' produces spurs along its twigs. These are short

stem Stem or STEM most commonly refers to: * Plant stem, a structural axis of a vascular plant * Stem group * Science, technology, engineering, and mathematics Stem or STEM can also refer to: Language and writing * Word stem, part of a word respon ...

s with closely spaced leaves. The

foliage A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, f ...

is dimorphic. According to a recent description "short shoots bear broadly

cordate Cordate is an adjective meaning ' heart-shaped' and is most typically used for: * Cordate (leaf shape), in plants * Cordate axe, a prehistoric stone tool See also * Chordate A chordate ( ) is a bilaterian animal belonging to the phyl ...

reniform Reniform is an adjective meaning "kidney-shaped". It may refer to: * Reniform habit, a type of crystal shape * Reniform leaf, a plant leaf shape * Reniform seed, a plant seed shape * Reniform stigma, a spot on the wings of certain moths See ...

, palmately veined leaves with crenate margins; long shoots bear elliptic to broadly

ovate Ovate may refer to: * Ovate (egg-shaped) leaves, tepals, or other botanical parts *Ovate, a type of prehistoric stone hand axe * Ovates, one of three ranks of membership in the Welsh Gorsedd * Vates or ovate, a term for ancient Celtic bards ...

leaves with

entire Entire may refer to: * Entire function, a function that is holomorphic on the whole complex plane * Entire (animal), an indication that an animal is not neutered * Entire (botany) This glossary of botanical terms is a list of definitions o ...

or finely serrate margins."Peter K. Endress. 1993. "Cercidiphyllaceae" pages 250-252. In: Klaus Kubitzki (editor). ''The Families and Genera of Vascular Plants''. volume II. Springer-Verlag: Berlin; Heidelberg, Germany. Leaf size varies from 3–8 cm long and 3–5.5 cm broad. The genus is

dioecious Dioecy ( ; ; adj. dioecious, ) is a characteristic of certain species that have distinct unisexual individuals, each producing either male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproduction is ...

, having separate male and female trees. The small inconspicuous

flower Flowers, also known as blooms and blossoms, are the reproductive structures of flowering plants ( angiosperms). Typically, they are structured in four circular levels, called whorls, around the end of a stalk. These whorls include: calyx, m ...

s are produced in early spring and wind-pollinated; the

fruit In botany, a fruit is the seed-bearing structure in flowering plants (angiosperms) that is formed from the ovary after flowering. Fruits are the means by which angiosperms disseminate their seeds. Edible fruits in particular have long propaga ...

is a cluster of 2-4 small pods, each pod 1–2 cm long with numerous small, flattened and winged

seed In botany, a seed is a plant structure containing an embryo and stored nutrients in a protective coat called a ''testa''. More generally, the term "seed" means anything that can be Sowing, sown, which may include seed and husk or tuber. Seeds ...

s. The fruits mature in autumn and release their seeds in autumn through winter. The leaves have a strong, sweet smell in the fall, described as caramel or Madeira cake-like. The smell comes from a combination of

maltol Maltol is a naturally occurring organic compound that is used primarily as a flavor enhancer. It is found in nature in the bark of larch trees and in the needles of pine trees, and is produced during the roasting of malt (from which it gets its n ...

and a sugary compound in the leaves and is strongest when they are brown. In German, ''Cercidiphyllum'' trees are named after their scent; or ("pie tree" or "gingerbread tree").

Nomenclature

Katsura () is the Japanese name for the tree. The scientific name ''Cercidiphyllum'' refers to the close resemblance of the leaves to those of ''

'' (redbuds); these two unrelated genera can however be distinguished easily as redbud leaves are alternate, not opposite.

Species

The two species are: *''

''. Throughout the range of the genus. Typically a multi-stemmed tree to 40–45 m tall in the wild, though typically smaller in cultivation. Bark rough, furrowed. Leaves smaller, not over 4.5 cm long and 3.2 cm broad;

stipule In botany, a stipule is an outgrowth typically borne on both sides (sometimes on just one side) of the base of a leafstalk (the petiole (botany), petiole). They are primarily found among dicots and rare among monocots. Stipules are considered part ...

s falling soon after leafing out in spring. Seed winged only at lower end. Plants from China were at one time separated as ''C. japonicum'' var. ''sinense'', but no consistent difference between Japanese and Chinese origins has been found. *'' Cercidiphyllum magnificum''.

Endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to central Honshū, where it grows at higher altitudes than ''C. japonicum''. A small tree, not more than 10 m tall. Bark smooth. Leaves larger, up to 8 cm long and 5.5 cm broad; stipules persistent. Seed winged at both ends.

Cultivation

Katsura is grown as an

ornamental tree Ornamental plants or ''garden plants'' are plants that are primarily grown for their beauty but also for qualities such as scent or how they shape physical space. Many flowering plants and garden varieties tend to be specially bred cultivars th ...

for its delicate heart-shaped leaves and bright autumn colour, a mix of bright yellow, pink and orange-red. Where conditions are suitable, it is fast-growing, but it is very sensitive to

drought A drought is a period of drier-than-normal conditions.Douville, H., K. Raghavan, J. Renwick, R.P. Allan, P.A. Arias, M. Barlow, R. Cerezo-Mota, A. Cherchi, T.Y. Gan, J. Gergis, D. Jiang, A. Khan, W. Pokam Mba, D. Rosenfeld, J. Tierney, ...

and needs deep, permanently moist soil. Under drought conditions, the species will abscise its leaves; however refoliation may occur once water is made available. Of particular interest is the scent produced by the leaves in the autumn, resembling burnt brown sugar or cotton candy. Trees in cultivation, like those in natural environments, tend to sucker from the base when young and become multi-stemmed at maturity; pruning to maintain a single stem is not advised. Within ''Cercidiphyllum japonicum'', several

cultivar A cultivar is a kind of Horticulture, cultivated plant that people have selected for desired phenotypic trait, traits and which retains those traits when Plant propagation, propagated. Methods used to propagate cultivars include division, root a ...

s with pendulous branches are grown for their unique weeping habit. Two general types exist. Those with a strong central leader, or excurrent growth, are all one clone originating in Morioka City, Japan. This cultivar is known as 'Morioka Weeping' and can reach over in height. The other type fails to form a central leader and is rounded in habit. There are several clones of this, including 'Amazing Grace' and 'Tidal Wave'. Both the species ''C. japonicum'' and the weeping form ''C. japonicum'' f. ''pendulum'' have gained the

Royal Horticultural Society The Royal Horticultural Society (RHS), founded in 1804 as the Horticultural Society of London, is the UK's leading gardening charity. The RHS promotes horticulture through its five gardens at Wisley (Surrey), Hyde Hall (Essex), Harlow Carr ...

Award of Garden Merit The Award of Garden Merit (AGM) is a long-established award for plants by the British Royal Horticultural Society (RHS). It is based on assessment of the plants' performance under UK growing conditions. It includes the full range of cultivated p ...

Uses

Katsura wood is often used to make gobans, i.e. boards for the game Go.

Fossil record

The genus is known from fossils at the end of the

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

(

Maastrichtian The Maastrichtian ( ) is, in the International Commission on Stratigraphy (ICS) geologic timescale, the latest age (geology), age (uppermost stage (stratigraphy), stage) of the Late Cretaceous epoch (geology), Epoch or Upper Cretaceous series (s ...

) of North America, and the Cenozoic of North America, Europe and Asia.

Gallery

File:Katsura Tree Cercidiphyllum japonicum Trunk Bark 2000px.jpg, ''Cercidiphyllum japonicum'' Trunk bark File:Cercidiphyllum japonicum JPG01b.jpg, ''Cercidiphyllum japonicum'' leaves File:Great katsura of wachi01s3000.jpg, "great Katsura of Wachi" File:Cercidiphyllum japonicum JPG01d.jpg, ''Cercidiphyllum japonicum'' in the autumn

References

Sources

* * * *

External links

''Cercidiphyllum'' images at the Arnold Arboretum of Harvard University Plant Image Database
* Dosman, Michael
"The Katsure Collection."
''Arnold Arboretum of Harvard University website'', Fall 2012. Accessed 1 May 2020. {{Go (game) Dioecious plants Go equipment Japanese woods Saxifragales Saxifragales genera Extant Late Cretaceous first appearances Taxa named by Philipp Franz von Siebold Taxa named by Joseph Gerhard Zuccarini