Dipentodon

Dipentodon
Scientific classification
Kingdom: Plantae
Clade: Angiosperms
Clade: Eudicots
Clade: Rosids
Order: Huerteales
Family: Dipentodontaceae
Genus: Dipentodon
Dunn
Species: D. sinicus
Binomial name
Dipentodon sinicus
Dunn

Dipentodon is a genus of flowering plants in the family Dipentodontaceae. Its only species, Dipentodon sinicus, is a small, deciduous tree native to southern China, northern Myanmar, and northern India.[2] It has been little studied and until recently its affinities remained obscure.

Description

Dipentodon sinicus is a small, deciduous tree. The leaves are stipulate, alternate, and simple, with serrate margins. The inflorescence is variable in form, usually an abbreviated, umbelliform cyme [2] containing 25 to 30 small flowers. The flowers are actinomorphic and yellowish green. The sepals and petals are only weakly differentiated, usually 5, rarely to 7 in number, free, or united only at the base.[2] The hypanthium is very short [3] or else the ovary is superior.[2] The nectary disk is intrastaminal. The stamens are opposite the sepals. The ovary consists of three united carpels with two ovules per carpel. The ovary is 1-loculate, but partly 3-loculate at its base. The fruit is a 1-seeded drupaceous capsule.

History

Dipentodon was named and first described in 1911 by Stephen Troyte Dunn in what is now called the Kew Bulletin.[4] At that time, Dunn wrote:

“ The name Dipentodon, proposed for it, refers to the most remarkable character possessed by the flowers in the
exact similarity of the calyx teeth and petals (if I rightly call them so) and their insertion so nearly in one whorl
that the appearance is given of a ten-toothed perianth.		 ”

Dipentodon was placed in its own family by Elmer Drew Merrill in 1941,[5] but this placement was not generally followed. Instead, most authors put Dipentodon in the ill-defined and heterogeneous family Flacourtiaceae.[6][7][8] In the twenty-first century, Flacourtiaceae is recognized by only a few taxonomists,[9] and then only in a much narrower sense than it had been.[2][10] Dipentodon is unrelated to Flacourtiaceae sensu stricto, a segregate of Salicaceae.[11][12] Molecular phylogenetic studies have led to the widespread acceptance of the family Dipentodontaceae and its placement in the order Huerteales.[3] Some authors have defined the family as consisting only of Dipentodon.[13] Others, following the recommendation of a 2006 study,[14] have included Perrottetia.[2][15] When the APG II classification was published in 2003, the taxonomic position of Dipentodon was still unknown and it was placed incertae sedis in the angiosperms. It was listed in the appendix under TAXA OF UNCERTAIN POSITION.

References

  1. ↑ World Conservation Monitoring Centre (1998). "Dipentodon sinicus". IUCN Red List of Threatened Species. Version 2011.2. International Union for Conservation of Nature. Retrieved 14 April 2012.
  2. 1 2 3 4 5 6 Jinshuang Ma and Bruce Bartholomew. 2008. "Dipentodontaceae" pages 494-495. In: Zhengyi Wu, Peter H. Raven, and Deyuan Hong (editors). Flora of China volume 11. Science Press: Beijing, China; Missouri Botanical Garden Press: St. Louis, Missouri, USA.
  3. 1 2 Worberg Andreas; Alford Mac H.; Quandt Dietmar; Borsch Thomas (2009). "Huerteales sister to Brassicales plus Malvales, and newly circumscribed to include Dipentodon, Gerrardina, Huertea, Perrottetia, and Tapiscia". Taxon. 58 (2): 468–478.
  4. ↑ Dunn Stephen T (1911). "Dipentodon. A New Genus of Uncertain Systematic Position". Bulletin of Miscellaneous Information. Kew. 1911 (7): 310–313. doi:10.2307/4119481.
  5. ↑ Merrill Elmer D (1941). "Pages 69,73 In: The Upper Burma plants collected by Captain F. Kingdon Ward on the Vernay-Cutting Expedition, 1938-1939". Brittonia. 4: 20–188. doi:10.2307/2804985.
  6. ↑ YL Peng; ZD Chen; X Gong; Y Zhong; SH Shi Peng (2003). "Phylogenetic position of Dipentodon sinicus: evidence from DNA sequences of chloroplast rbcL, nuclear ribosomal 18S, and mitochondria matR genes" (PDF). Bull. Acad. Sin. 44: 217–222. ISSN 0006-8063.
  7. ↑ (in Chinese) Wu, Lu, A.-M., Tang, Y.-C., Chen, Z.-D., & Li, D.-Z. (2002). Synopsis of a new "polyphyletic-polychronic-polytopic" system of the angiosperms. Acta Phytotax. Sinica, 40: 298-322.
  8. ↑ Wu, Lu, A.-M., Tang, Y.-C., Chen, Z.-D., & Li, D.-Z. (2003). The Families and Genera of Angiosperms in China: A Comprehensive Analysis. Science Press, Beijing.
  9. ↑ Sue Zmarzty et alii. (in press). "Salicaceae" In: The Families and Genera of Vascular Plants. Springer-Verlag: Berlin;Heidelberg, Germany.
  10. ↑ Chase Mark W.; Zmarzty Sue; Lledó M. Dolores; Wurdack Kenneth J.; Swensen Susan M.; Fay Michael F. (2002). "When in doubt, put it in Flacourtiaceae: a molecular phylogenetic analysis based on plastid rbcL DNA sequences". Kew Bulletin. 57 (1): 141–181. doi:10.2307/4110825.
  11. ↑ Hengchang Wang; Michael J. Moore; Pamela S. Soltis; Charles D. Bell; Samuel F. Brockington; Roolse Alexandre; Charles C. Davis; Maribeth Latvis; Steven R. Manchester; Douglas E. Soltis (10 Mar 2009). "Rosid radiation and the rapid rise of angiosperm-dominated forests". Proceedings of the National Academy of Sciences. 106 (10): 3853–3858. PMC 2644257 Freely accessible. PMID 19223592. doi:10.1073/pnas.0813376106.
  12. ↑ Zhu, Xy; Chase, Mw; Qiu, Yl; Kong, Hz; Dilcher, Dl; Li, Jh; Chen, Zd (November 2007). "Mitochondrial matR sequences help to resolve deep phylogenetic relationships in rosids" (PDF). BMC Evolutionary Biology. 7: 217. PMC 2222252 Freely accessible. PMID 17996110. doi:10.1186/1471-2148-7-217.
  13. ↑ Vernon H. Heywood, Richard K. Brummitt, Ole Seberg, and Alastair Culham. Flowering Plant Families of the World. Firefly Books: Ontario, Canada. (2007). ISBN 978-1-55407-206-4.
  14. ↑ Li-Bing Zhang; Simmons Mark P (2006). "Phylogeny and Delimitation of the Celastrales Inferred from Nuclear and Plastid Genes". Systematic Botany. 31 (1): 122–137. doi:10.1600/036364406775971778.
  15. ↑ Peter F. Stevens (2001 onwards). "Huerteales". In: Angiosperm Phylogeny Website. In: Missouri Botanical Garden Website. (see External links below)
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