Eucalypt is any woody plant with capsule fruiting bodies belonging to one of seven closely related genera (of the tribe Eucalypteae) found across Australia: Eucalyptus, Corymbia, Angophora, Stockwellia, Allosyncarpia, Eucalyptopsis and Arillastrum.
[2] For an example of changing historical perspectives, in 1991, largely genetic evidence indicated that some prominent Eucalyptus species were actually more closely related to Angophora than to other eucalypts; they were accordingly split off into the new genus Corymbia.
[1][3][4][5] The extant genera Stockwellia, Allosyncarpia, Eucalyptopsis and Arillastrum comprise six known species, restricted to monsoon forests and rainforests in north-eastern Australia, the Arnhem Land plateau, New Guinea, the Moluccas and New Caledonia.
According to genetic, fossil and morphological evidence, it is hypothesised that they evolved into separate taxa before the evolution of the more widespread and well-known genera Eucalyptus, Corymbia and Angophora, and all of their many species.
[citation needed] Over 700 eucalypt species dominate landscapes all over Australia, but diversity is reduced in rainforests and arid environments.