Which Australian tree is the only species in the genus Wollemia?

The Australian tree that is the only species in the genus Wollemia is the Wollemi pine.

Its scientific name is Wollemia nobilis, a conifer in the Araucariaceae family. Although its common name includes “pine,” it is not a true pine in the genus Pinus; it is more closely related to Agathis and Araucaria. The genus is named for Wollemi National Park in New South Wales.

The species became famous after its discovery in 1994 by canyoner and park officer David Noble in remote sandstone gorges about 150 kilometres northwest of Sydney. It had previously been known only from fossil evidence and was widely described as a “living fossil,” although the fossil record does not unambiguously prove that ancient fossils belong to Wollemia.

The Wollemi pine is critically endangered. Fewer than 60 mature wild trees are known, and the exact location of the groves is protected. Plants propagated from cultivated material are now grown in gardens and arboreta around the world, helping reduce pressure on the fragile wild population.