Xanthocyparis

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Xanthocyparis
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Gymnospermae
Division: Pinophyta
Class: Pinopsida
Order: Cupressales
Family: Cupressaceae
Genus: Xanthocyparis
Farjon & T.H.Nguyên[3]
Species:
X. vietnamensis
Binomial name
Xanthocyparis vietnamensis
Farjon & T.H.Nguyên[2]
Synonyms[2]

Species:

  • Callitropsis vietnamensis (Farjon & T.H.Nguyên) D.P.Little
  • Cupressus vietnamensis (Farjon & T.H.Nguyên) Silba

Xanthocyparis is a genus of cypresses in the family Cupressaceae. As of August 2021, it has only one species, Xanthocyparis vietnamensis,[3] native to Vietnam and southeast China.[2] 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[edit]

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.[4] This was based in part on the discovery that C. nootkatensis was more closely related to the genus Cupressus than to Chamaecyparis.[5]

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).[6] Callitropsis had been described by Anders Sandøe Ørsted in 1864, but this name had been overlooked by Farjon and most other authors; under the rules of the International Code of Botanical Nomenclature, 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,[7] a decision that was ratified at the International Botanical Congress in 2011.[8]

Little et al. also presented evidence that Cupressus is paraphyletic with respect to Juniperus and Xanthocyparis, with the North American species of Cupressus being more closely related to Xanthocyparis than they are to the European and Asian Cupressus species.[6] These species were transferred to "Callitropsis" by Damon Little in 2006,[9] although this transfer was not universally accepted.[10] In 2009, most of the North American species previously included in "Callitropsis" were placed in a separate genus, Hesperocyparis.[11]

A 2021 molecular study found Xanthocyparis to be sister to a clade comprising Hesperocyparis and Callitropsis, with the clade containing all three being sister to a clade comprising Juniperus and Cupressus sensu stricto.[12]

Distribution[edit]

Xanthocyparis vietnamensis was originally described as endemic to Vietnam, being native only to the karst limestone mountains of the Hà Giang Province in northern Vietnam.[13] It has since also been recorded in Cao Bằng and Tuyên Quang provinces in Vietnam, as well as southeast China (Guangxi).[2]

References[edit]

  1. ^ Thomas, P. 2013. Xanthocyparis vietnamensis. The IUCN Red List of Threatened Species 2013: e.T44028A2991576. https://dx.doi.org/10.2305/IUCN.UK.2013-1.RLTS.T44028A2991576.en. Accessed on 11 April 2023.
  2. ^ a b c d "Xanthocyparis vietnamensis Farjon & T.H.Nguyên". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 2021-08-27.
  3. ^ a b "Xanthocyparis Farjon & T.H.Nguyên". Plants of the World Online. Royal Botanic Gardens, Kew. Retrieved 2021-08-27.
  4. ^ A. Farjon; Nguyen Tien Hiep; D. K. Harder; Phan Ke Loc & L. Averyanov (2002). "A new genus and species in the Cupressaceae (Coniferales) from northern Vietnam, Xanthocyparis vietnamensis". Novon. 12 (2): 179–189. doi:10.2307/3392953. JSTOR 3392953.
  5. ^ Paul A. Gadek; Deryn L. Alpers; Margaret M. Heslewood & Christopher J. Quinn (2000). "Relationships within Cupressaceae sensu lato: a combined morphological and molecular approach". American Journal of Botany. 87 (7): 1044–1057. doi:10.2307/2657004. JSTOR 2657004. PMID 10898782.
  6. ^ a b Damon P. Little; Andrea E. Schwarzbach; Robert P. Adams & Chang-Fu Hsieh (2004). "The circumscription and phylogenetic relationships of Callitropsis and the newly described genus Xanthocyparis (Cupressaceae)". American Journal of Botany. 91 (11): 1872–1881. doi:10.3732/ajb.91.11.1872. PMID 21652334.
  7. ^ Robert R. Mill & Aljas Farjon (2006). "Proposal to conserve the name Xanthocyparis against Callitropsis Oerst. (Cupressaceae)". Taxon. 55 (1): 229–231. doi:10.2307/25065550. JSTOR 25065550.
  8. ^ Fred R. Barrie (2011). "Report of the General Committee: 11". Taxon. 60 (4): 1211–1214. doi:10.1002/tax.604026.
  9. ^ Damon P. Little (2006). "Evolution and circumscription of the true cypresses (Cupressaceae: Cupressus)". Systematic Botany. 31 (3): 461–480. doi:10.1600/036364406778388638. JSTOR 25064176.
  10. ^ C. Michael Hogan & Michael P. Frankis (January 27, 2009). "Monterey Cypress: Cupressus macrocarpa". iGoTerra. Retrieved November 15, 2013.
  11. ^ Robert P. Adams; Jim A. Bartel & Robert A. Price (2009). "A new genus, Hesperocyparis, for the cypresses of the Western Hemisphere" (PDF). Phytologia. 91 (1): 160–185.
  12. ^ Stull, Gregory W.; Qu, Xiao-Jian; Parins-Fukuchi, Caroline; Yang, Ying-Ying; Yang, Jun-Bo; Yang, Zhi-Yun; Hu, Yi; Ma, Hong; Soltis, Pamela S.; Soltis, Douglas E.; Li, De-Zhu (July 19, 2021). "Gene duplications and phylogenomic conflict underlie major pulses of phenotypic evolution in gymnosperms". Nature Plants. 7 (8): 1015–1025. doi:10.1038/s41477-021-00964-4. ISSN 2055-0278. PMID 34282286. S2CID 236141481.
  13. ^ Thompson, Christian (2008-12-15). "First Contact in the Greater Mekong" (PDF). World Wildlife Fund. Retrieved 2008-12-20.