The Australian sub-region consists of Australia, Tasmania, New Caledonia and New Zealand, and, though partly lying within the tropic is most naturally treated as a whole.
Myrtaceae comes next with Eucalyptus, which forms three-fourths of the forests, and Melaleuca; both are absent from New Caledonia and New Zealand; a few species of the former extend to New Guinea and one of the latter to Malaya.
The so-called oaks of Australia are Casuarma, which also occurs in New Caledonia, but is wanting in New Zealand.
Amongst Conifers, Podocar pus is found throughout, Agathis is common to Australia, New Zealand and New Caledonia; Araucaria ~ ~he first and last.
Of Cycads, Australia and New Caledonia have Cycas, and the former the endemic Macrozamia and Bowenia.