The plains were once lightly forested with mainly gum, coolibah, box, wilga, belah, myall, Cypress pine and leopardwood trees.
"One mile up the river from the last point is a small creek of fresh water, issuing from an extensive lagoon clothed with arborescent species of Metrosideros of great beauty. The banks are covered with the most interesting plants, amongst which I observed two species of Calytris, a species of Acacia with a scolopendrous-stem, and several Papilionaceous plants. The Angophoras on the flats are gigantic."
Preiss is commemorated in the names of about 100 species of flora in Western Australia, including plants in the genera Acacia, Allocasuarina, Eucalyptus, Grevillea, Hakea, Kunzea, Melaleuca, Santalum, Xanthorrhoea and Callitris.
Where Galahs readily occupy cleared and part-cleared land, Major Mitchell's Cockatoo requires extensive woodlands, particularly favouring Callitris, Allocasuarina and Eucalyptus.
Subspecies cunninghamii is associated with the trees scribbly gum species Eucalyptus rossii and E. sclerophylla, rough-barked apple (Angophora floribunda), Callitris species, and mallees such as Eucalyptus multicaulis and narrow-leaved mountain mallee (E. apiculata).