Araucaria

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Araucaria
Temporal range: Jurassic–Recent[1][2]
Scientific classification
Kingdom:Plantae
Division:Pinophyta
Class:Pinopsida
Order:Pinales
Family:Araucariaceae
Genus:Araucaria
Juss.
Type species
Araucaria araucana [3]
Pav.
Worldwide distribution of Araucaria species.
 
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Araucaria
Temporal range: Jurassic–Recent[1][2]
Scientific classification
Kingdom:Plantae
Division:Pinophyta
Class:Pinopsida
Order:Pinales
Family:Araucariaceae
Genus:Araucaria
Juss.
Type species
Araucaria araucana [3]
Pav.
Worldwide distribution of Araucaria species.

Araucaria is a genus of evergreen coniferous trees in the family Araucariaceae. There are 19 extant species in the genus, with a Gondwanan natural distribution in New Caledonia (where 13 species are endemic), Norfolk Island, eastern Australia, New Guinea, Argentina, Chile, and southern Brazil.

Description[edit]

Araucaria are mainly large trees with a massive erect stem, reaching a height of 30–80 metres (98–262 ft). The horizontal, spreading branches grow in whorls and are covered with leathery or needle-like leaves. In some species, the leaves are narrow awl-shaped and lanceolate, barely overlapping each other, in others they are broad and flat, and overlap broadly.[4]

The trees are mostly dioecious, with male and female cones found on separate trees,[5] though occasional individuals are monoecious or change sex with time.[6] The female cones, usually high on the top of the tree, are globose, and vary in size between species from 7 to 25 centimetres (2.8 to 9.8 in) diameter. They contain 80–200 large, edible seeds, similar to pine nuts though larger. The male cones are smaller, 4–10 cm (1.6–3.9 in) long, and narrow to broad cylindrical, 1.5–5.0 cm (0.6–2.0 in) broad.

The genus is familiar to many people as the genus of the distinctive Chilean pine or monkey-puzzle tree (Araucaria araucana). The genus is named after the Spanish exonym Araucano ("from Arauco") applied to the Mapuches of central Chile and south-west Argentina whose territory incorporates natural stands of this genus. The Mapuche people call it pehuén, and consider it sacred.[4] Some Mapuches living in the Andes name themselves Pehuenches ("people of the pehuén") as they traditionally harvested the seeds extensively for food.[7][8]

No distinct vernacular name exists for the genus. Many are called "pine", although they are only distantly related to true pines, in the genus Pinus.

Distribution and paleoecology[edit]

Three members of the genus growing together – left to right, Araucaria columnaris, Araucaria cunninghamii and Araucaria bidwillii

Members of Araucaria are found in Chile, Argentina, southern Brazil, New Caledonia, Norfolk Island, Australia, and New Guinea. There is also a significant, naturalized population of Araucaria columnaris – "Cook's pine", on the island of Lanai, in Hawaii, USA.[9] Many if not all current populations are relicts, and of restricted distribution. They are found in forest and maquis shrubland, with an affinity for exposed sites. These columnar trees are living fossils, dating back to early in the Mesozoic age. Fossil records show that the genus also formerly occurred in the northern hemisphere until the end of the Cretaceous period. By far the greatest diversity exists in New Caledonia, due to the island's long isolation and stability.[4]

It is believed that the long necks of sauropod dinosaurs may have evolved specifically to browse the foliage of the typically very tall Araucaria trees. The global distribution of vast forests of Araucaria during the Jurassic makes it likely that they were the major high energy food source for adult sauropods.[10]

Classification and species list[edit]

Araucaria columnaris sapling with distinctive axial bud.
The leaves of Araucaria heterophylla
Petrified cone of Araucaria mirabilis from Patagonia, Argentina dating from the Jurassic Period (approx. 157 mya)
Araucaria sp., either A. angustifolia or hybrid A. angustifolia × A. araucana; cultivated, Santa Rosa, Argentina.

There are four extant sections and two extinct sections in the genus, sometimes treated as separate genera.[4][11][12] Genetic studies indicate that the extant members of the genus can be subdivided into two large clades – the first consisting of the section Araucaria, Bunya, and Intermedia; and the second of the strongly monophyletic section Eutacta. Sections Eutacta and Bunya are both the oldest taxa of the genus, with Eutacta possibly older.[13]

Taxa marked with are extinct.

Araucaria bindrabunensis (previously classified under section Bunya) has been transferred to the genus Araucarites.

Uses[edit]

Some of the species are relatively common in cultivation because of their distinctive, formal symmetrical growth habit. Several species are economically important for timber production. The edible large seeds of A. araucana and A. bidwillii are also eaten as food (particularly among the Mapuche people and Native Australians).[4]

In popular culture[edit]

See also[edit]

References[edit]

  1. ^ Michael Knapp, Ragini Mudaliar, David Havell, Steven J. Wagstaff & Peter J. Lockhart (2007). "The drowning of New Zealand and the problem of Agathis". Systematic Biology 56 (5): 862–870. doi:10.1080/10635150701636412. PMID 17957581. 
  2. ^ S. Gilmore & K. D. Hill (1997). "Relationships of the Wollemi Pine (Wollemia nobilis) and a molecular phylogeny of the Araucariaceae" (PDF). Telopea 7 (3): 275–290. 
  3. ^ K. D. Hill (1998). "Araucaria". Flora of Australia Online 48. Australian Biological Resources Study. Retrieved May 7, 2012. 
  4. ^ a b c d e Christopher J. Earle (December 12, 2010). "Araucaria Jussieu 1789". The Gymnosperm Database. Retrieved November 13, 2011. 
  5. ^ "Practical Seedling Growing: Growing Araucaria from Seeds". Arboretum de Villardebelle. Retrieved November 18, 2011. 
  6. ^ Michael G. Simpson (2010). Plant Systematics. Academic Press. p. 151. ISBN 978-0-12-374380-0. 
  7. ^ "Araucaria columnaris". National Tropical Botanical Garden. Retrieved November 18, 2011. 
  8. ^ Francisco P. Moreno (November 2004). "Pehuenches: "The people from the Araucarias forests"". Museo de la Patagonia. Retrieved November 18, 2011. 
  9. ^ The Pine Trees of Lanai
  10. ^ Jürgen Hummel, Carole T. Gee, Karl-Heinz Südekum, P. Martin Sander, Gunther Nogge & Marcus Clauss (2008). "In vitro digestibility of fern and gymnosperm foliage: implications for sauropod feeding ecology and diet selection". Proceedings of the Royal Society B: Biological Sciences 275 (1638): 1015–1021. doi:10.1098/rspb.2007.1728. PMC 2600911. PMID 18252667. 
  11. ^ Michael Black & H. W. Pritchard (2002). Desiccation and Survival in Plants: Drying without Dying. CAB International. p. 246. ISBN 978-0-85199-534-2. 
  12. ^ James E. Eckenwalder (2009). Conifers of the World: the Complete Reference. Timber Press. p. 149. ISBN 978-0-88192-974-4. 
  13. ^ a b Hiroaki Setoguchi, Takeshi Asakawa Osawa, Jean-Cristophe Pintaud, Tanguy Jaffré & Jean-Marie Veillon (1998). "Phylogenetic relationships within Araucariaceae based on rbcL gene sequences" (PDF). American Journal of Botany 85 (11): 1507–1516. doi:10.2307/2446478. PMID 21680310. 
  14. ^ Mary E. Dettmann & H. Trevor Clifford (2005). "Biogeography of Araucariaceae" (PDF). In J. Dargavel. Australia and New Zealand Forest Histories. Araucaria Forests. Occasional Publication 2. Australian Forest History Society. pp. 1–9. 
  15. ^ Erich Götz (1980). Pteridophytes and Gymnosperms. Springer. p. 295. ISBN 978-3-540-51794-8. 

External links[edit]