''Araucaria rulei'' (Rule araucaria, graceful pine) is a species of

conifer Conifers () are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a sin ...

in the family

Araucariaceae Araucariaceae is a Family (biology), family of conifers with three living Genus, genera, ''Araucaria'', ''Agathis'', and ''Wollemia''. While the family's native distribution is now largely confined to the Southern Hemisphere, except for a few spe ...

. It is

endemic Endemism is the state of a species being found only 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 foun ...

New Caledonia New Caledonia ( ; ) is a group of islands in the southwest Pacific Ocean, southwest of Vanuatu and east of Australia. Located from Metropolitan France, it forms a Overseas France#Sui generis collectivity, ''sui generis'' collectivity of t ...

, where it is an

endangered species An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...

. Its populations are fragmented and are generally made up of scattered individuals. It is restricted to

serpentine soil Serpentine soil is an uncommon soil type produced by weathered ultramafic rock such as peridotite and its metamorphic derivatives such as serpentinite. More precisely, serpentine soil contains minerals of the serpentine subgroup, especially an ...

s, often with high

nickel Nickel is a chemical element; it has 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 slo ...

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 w ...

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
/ref>

References

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