''Xanthocyparis'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

of cypresses in the family Cupressaceae. , it has only one species, ''Xanthocyparis vietnamensis'', native to

Vietnam Vietnam or Viet Nam ( vi, Việt Nam, ), officially the Socialist Republic of Vietnam,., group="n" is a country in Southeast Asia, at the eastern edge of mainland Southeast Asia, with an area of and population of 96 million, making i ...

and southeast China. It is commonly known as the Vietnamese golden cypress. The Nootka cypress, '' Cupressus nootkatensis'' or ''Callitropsis nootkatensis'', was also placed in the genus, but this has been rejected.

Taxonomy

In 2002, Aljos Farjon and others described the new genus ''Xanthocyparis'' to accommodate the new Vietnamese species '' X. vietnamensis'' and another species, the Nootka cypress, which had been formerly included in the genus '' Chamaecyparis'' as ''C. nootkatensis''. This was based in part on the discovery that ''C. nootkatensis'' was more closely related to the genus '' Cupressus'' than to ''Chamaecyparis''. In 2004, Damon Little and others, while confirming the above relationship with further evidence, pointed out that as circumscribed by Farjon ''et al.'', ''Xanthocyparis'' included the type species of ''Callitropsis'' (''Cupressus nootkatensis'', a synonym of ''Chamaecyparis nootkatensis'' and ''Xanthocyparis nootkatensis''). ''Callitropsis'' had been described by

Anders Sandøe Ørsted Anders Sandøe Ørsted (21 December 1778 – 1 May 1860) was a Danish lawyer, politician and jurist. He served as the Prime Minister of Denmark in 1853–1854. Biography He studied philosophy and law at the University of Copenhagen and was ...

in 1864, but this name had been overlooked by Farjon and most other authors; under the rules of the

International Code of Botanical Nomenclature The ''International Code of Nomenclature for algae, fungi, and plants'' (ICN) is the set of rules and recommendations dealing with the formal botanical names that are given to plants, fungi and a few other groups of organisms, all those "trad ...

, ''Callitropsis'' as the earlier-published name had nomenclatural priority over ''Xanthocyparis'' if that genus included ''Cupressus nootkatensis''. Little ''et al.'' therefore recognized ''Xanthocyparis'' as a synonym of ''Callitropsis''. The name ''Xanthocyparis'' was proposed for conservation over ''Callitropsis'', a decision that was ratified at the

International Botanical Congress International Botanical Congress (IBC) is an international meeting of botanists in all scientific fields, authorized by the International Association of Botanical and Mycological Societies (IABMS) and held every six years, with the location rotati ...

in 2011. Little ''et al.'' also presented evidence that ''Cupressus'' is paraphyletic with respect to ''

Juniperus Junipers are coniferous trees and shrubs in the genus ''Juniperus'' () of the cypress family Cupressaceae. Depending on the taxonomy, between 50 and 67 species of junipers are widely distributed throughout the Northern Hemisphere, from the Arcti ...

'' and ''Xanthocyparis'', with the North American species of ''Cupressus'' being more closely related to ''Xanthocyparis'' than they are to the

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located entirel ...

an and Asian ''Cupressus'' species. These species were transferred to "''Callitropsis''" by Damon Little in 2006, although this transfer was not universally accepted. In 2009, most of the North American species previously included in "''Callitropsis''" were placed in a separate genus, ''

Hesperocyparis ''Hesperocyparis'' (western cypress) is a genus of trees in the family Cupressaceae, containing North American species otherwise assigned to the genus ''Cupressus''. They are found throughout western North America. Only a few species have wide ra ...

''. A 2021 molecular study found ''Xanthocyparis'' to be

sister A sister is a woman or a girl who shares one or more parents with another individual; a female sibling. The male counterpart is a brother. Although the term typically refers to a family, familial relationship, it is sometimes used endearingly to r ...

to a clade comprising ''

'' and ''Callitropsis'', with the clade containing all three being sister to a clade comprising ''Juniperus'' and ''Cupressus sensu stricto''.

Distribution

''Xanthocyparis vietnamensis'' was originally described as

endemic Endemism is the state of a species being found 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 found else ...

, being native only to the karst limestone mountains of the Hà Giang Province in northern Vietnam. It has since also been recorded in southeast China.

References

{{Taxonbar, from1=Q133623, from2=Q145841, from3=Q50840138, from4=Q17165388 Cupressaceae Conifer genera