Posidonia

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Posidonia

Scientific classification
Kingdom: Plantae
Division: Magnoliophyta
Class: Liliopsida
Order: Alismatales
Family: Posidoniaceae
Hutchinson
Genus: Posidonia
K.D.Koenig
Posidonia distribution range
Posidonia distribution range
Species

See text.

Pos(e)idonia also refers to the city of Magna Graecia later known as Paestum

Posidonia is a genus of flowering plants. It contains two to nine species of marine plants ("seagrass"), found in the seas of the Mediterranean and around the south coast of Australia.

The APG system (1998) and APG II system (2003) accept this genus as constituting the sole genus in the family Posidoniaceae, which it places in the order Alismatales, in the clade monocots. The AP-Website concludes that the three families Cymodoceaceae, Posidoniaceae and Ruppiaceae form a monophyletic group. Earlier systems classified this genus in the family Potamogetonaceae or in the family Posidoniaceae but belonging to order Zosterales.

[edit] Diversity

This is a list of species that are nominally contained by the genus:[1]

The species described by Linnaeus, Posidonia oceanica, is found in the mediterranean, the rest are located around the southern coast of Australia. All the other species occur in Western Australia. This arrangement was divided into two complexes; the Posidonia australis and Posidonia ostenfeldii groups.[5] Some species descriptions may only be regional characteristics, and may need further revision.[1]

In 2006 a huge clonal colony of Posidonia oceanica, was discovered south of the island of Ibiza. At 8 km across and possibly up to 100,000 years of age, it may be one of the largest and oldest clonal colonies on Earth.[6]

[edit] References

  1. ^ a b Mike van Keulen. The genus Posidonia König (nom. cons.) (Posidoniaceae).. Murdoch University.
  2. ^ Cambridge, M.L. and Kuo, J. (1979) Two new species of seagrass from Australia, Posidonia sinuosa and Posidonia angustifolia (Posidoniaceae). Aquat. Bot. 6, 307-328 f. Keulen
  3. ^ Kuo, J. and Cambridge, M.L. (1984) A taxonomic study of the Posidonia ostenfeldii complex (Posidoniaceae) with descriptions of four new Australian seagrasses. Aquat. Bot. 20, 267-95. f. Keulen
  4. ^ den Hartog, C. (1970) Seagrasses of the World. Verh. Kon. Ned. Akad. Wetens. Afd. Naturk. Ser. 2 59:139 f. Keulen
  5. ^ Kuo, J. and McComb, A.J. (1989) In: "Biology of Seagrasses. A treatise on the biology of seagrasses with special reference to the Australian region." (Eds. A.W.D. Larkum, A.J. McComb, S.A. Shepherd) (Aquatic Plant Studies 2) (Elsevier, Amsteredam). p. 6-73 f. Keulen
  6. ^ Ibiza Spotlight (28 May 2006). Ibiza's Monster Marine Plant. Retrieved on 2007-05-09.

[edit] External links