Araucarias
| Araucarias | ||||||||||||
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Chilean araucaria ( Araucaria araucana ) |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Araucariaceae | ||||||||||||
| Henkel & W. Hochst. |
The Araucariaceae are a very old family of plants within the conifers (Coniferopsida). They have a disjoint area in the southern hemisphere .
description
Vegetative characteristics
The araucaria are evergreen trees . The narrow or wide leaves are often parallel-veined. The seedlings have four cotyledons ( cotyledons ), but often are two each grow together.
Generative characteristics
They are single- sexed ( monoecious ) or dioecious ( dioecious ). The male cones are relatively large, cylindrical, with many sporophylls . The pollen grains are wingless. The pollen of the Araucariaceae consists of up to 40 vegetative cells, instead of two (remaining conifers Coniferales), four (in the case of the pine family, Pinaceae) or ten (in the case of the stone slab family, Podocarpaceae). The upright, female cones are relatively large, egg-shaped to almost spherical, contain milky sap and take about 2 years to mature. The seed scales have only one seed.
distribution
In the Jurassic and the Cretaceous Period , araucarias (Araucariaceae) were widespread worldwide, more precisely on the Gondwana continent.
After the continents drifted apart , the family now has a disjoint area . All species of the family have become extinct in the northern hemisphere and in Africa. In the southern hemisphere, members of the family today have their natural distribution in New Caledonia , New Zealand and Australia as well as in Malaysia and South America . With a total of 18 species, New Caledonia has a particularly high species density. 13 species are endemic to New Caledonia.
Systematics
The Araucariaceae family was set up in 1865 by Johann Baptist Henkel and Wilhelm Christian Hochstetter in Synopsis der Nädelhölzer , 1865. The type genus is Araucaria Juss.
The Araucariaceae family includes only three genera with a total of 41 species:
- Kauri trees ( Agathis Salisb. ): There are 17 to 21 species.
- Araucarias ( Araucaria Juss. ): There have been around 20 species as of 2017.
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Wollemia W.G. Jones, KDHill & JMAllen : There is only one type:
- Wollemia ( Wollemia nobilis W.G. Jones, KDHill & JMAllen ): It grows in the temperate rainforest in New South Wales, Australia . Only about 100 wild-growing specimens of this species are known, so it is a critically endangered species.
use
Some species such as the Chilean araucaria are used as park trees around the world. The Brazilian araucaria , on the other hand, is important as timber. It is used, for example, in instrument making, especially for inexpensive electric basses and guitars. The silver fir ( Araucaria heterophylla ) is one of the best-known species from this family. It prefers bright and cool locations and is also used as a houseplant .
literature
- Colin Tudge : The secret life of trees . Penguin books, London 2006, ISBN 978-0-14-101293-3 .
- Hiroaki Setoguchi, Takeshi Asakawa Osawa, Jeanchristophe Pintaud, Tanguy Jaffre, Jean-Marie Veillon: Phylogenetic Relationships within Araucariaceae based on RBCL Gene Sequences . In: American Journal of Botany . tape 85 , no. 11 , 1998, pp. 1507-1516 ( PDF, 0.2 MB ).
- H. Nimsch: Araucaria - All species of the genus in picture and text , Verlag Kessel, Remagen 2011. Cover picture Araucaria book , table of contents (PDF; 32 kB)
- Data sheet Araucariaceae at conifers.org - The Gymnosperm Database , 2019. (Section Systematics)
Individual evidence
- ↑ Tudge 2006, p. 103
- ↑ a b c d data sheet Araucariaceae at conifers.org - The Gymnosperm Database , 2019.
- ↑ Araucariaceae at Tropicos.org. Missouri Botanical Garden, St. Louis
Web links
- Wayne P. Armstrong: The Araucaria Family: Araucariaceae. In: Wayne's Word. Retrieved July 12, 2020 (English, information about araucarias.).
