''Araucaria rulei'' (Rule araucaria, graceful pine) is a species of conifer in the family

Araucariaceae Araucariaceae – also known as araucarians – is an extremely ancient family of coniferous trees. The family achieved its maximum diversity during the Jurassic and Cretaceous periods and the early Cenozoic, when it was distributed almost worldw ...

. It is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...

to New Caledonia, where it is an endangered species. Its populations are fragmented and are generally made up of scattered individuals. It is restricted to serpentine soils, often with high

nickel Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive but large pieces are slow ...

levels, and its natural range is almost completely restricted to areas rich in nickel.

Nickel mining in New Caledonia Nickel mining in New Caledonia is a major sector of the New Caledonian economy. The island contains about 7.1 million tonnes of nickel reserves, about 10% of the world's total. With an annual production of 200,000 tonnes in 2020, New Caledonia wa ...

has consequently been a major cause of its decline. ''Araucaria rulei'' grows to around 30 meters in height, with long slender branches arranged symmetrically around the trunk, which extend horizontally and then turn upwards and branch out at the end, giving the tree an appearance sometimes compared to a chandelier. Male and female cones are produced on the same tree but on different branches, with branches at the top of the tree tending to produce female cones, while branches lower down make male cones. The cones stay on the tree for 2–3 years while the seeds ripen, which are around 3 cm long when mature. It is a slow-growing plant with slow regeneration capabilities, though in its natural environment it is tolerant of both very dry conditions and high winds which many other species of araucaria will not tolerate. The species was named for an Australian nurseryman John Rule, and is sometimes grown as an ornamental tree in Australia, with its large smooth leaves and the symmetrical dome shaped growth habit of mature trees considered attractive.Araucaria rulei, The Gymnosperm Database
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References

rulei Endangered plants Trees of New Caledonia Endemic flora of New Caledonia Taxonomy articles created by Polbot {{conifer-stub