''Xanthocyparis'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

cypress Cypress is a common name for various coniferous trees or shrubs of northern temperate regions that belong to the family Cupressaceae. The word ''cypress'' is derived from Old French ''cipres'', which was imported from Latin ''cypressus'', the ...

es in the family

Cupressaceae Cupressaceae is a conifer family, the cypress family, with worldwide distribution. The family includes 27–30 genera (17 monotypic), which include the junipers and redwoods, with about 130–140 species in total. They are monoecious, subdio ...

. , 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 ''Callitropsis nootkatensis'', formerly known as ''Cupressus nootkatensis'' ( syn. ''Xanthocyparis nootkatensis'') is a species of trees in the cypress family native to the coastal regions of northwestern North America. This species goes by many ...

'' or ''Callitropsis nootkatensis'', was also placed in the genus, but this has been rejected.

Taxonomy

In 2002,

Aljos Farjon Aljos Farjon (born 1946) is a Dutch botanist specialized in conifers. After studying at Utrecht University he worked at Kew Gardens. He is a fellow of the Linnean Society of London The Linnean Society of London is a learned society dedicate ...

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 ''Chamaecyparis'', common names cypress or false cypress (to distinguish it from related cypresses), is a genus of conifers in the cypress family Cupressaceae, native to eastern Asia (Japan and Taiwan) and to the western and eastern margins of th ...

'' as ''C. nootkatensis''. This was based in part on the discovery that ''C. nootkatensis'' was more closely related to the genus ''

Cupressus ''Cupressus'' is one of several genera of evergreen conifers within the family Cupressaceae that have the common name cypress; for the others, see cypress. It is considered a polyphyletic group. Based on genetic and morphological analysis, the ge ...

'' 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 rotat ...

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 Continent#Subcontinents, subcontinent of Eurasia ...

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 familial relationship, it is sometimes used endearingly to refer to ...

to a

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

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 elsew ...

, being native only to the

karst Karst is a topography formed from the dissolution of soluble rocks such as limestone, dolomite, and gypsum. It is characterized by underground drainage systems with sinkholes and caves. It has also been documented for more weathering-resistant ro ...

limestone mountains of the

Hà Giang Province Hà is a Vietnamese surname. The name is transliterated as He in Chinese and Ha in Korean. Ha is the anglicized variation of the surname Hà. It is also the anglicized variation of Hạ. Notable people with the surname Hà *Hà Kiều Anh, Mis ...

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