From the knowledge I then had of New Holland, or Australian vegetation, I stated that its chief peculiarities existed in the greatest degree in a parallel, included between 33 degrees and 35 degrees S. lat. which I therefore called the principal parallel, but that these peculiarities or characteristic tribes, were found chiefly at its western and eastern extremities, being remarkably diminished in that intermediate portion, included between 133 degrees and 138 degrees, E. long.  These observations related entirely to the shores of Australia, its interior, being at that period altogether unknown; and the species of Australian plants, with which I was then acquainted, did not exceed 4200.  Since that time great additions have been made to the number, chiefly by Mr. Allan Cunningham, in his various journeys from Port Jackson, and on the shores of the North and North-west coasts during the voyages of Captain King whom he accompanied; by Messrs. William Baxter, James Drummond, and M. Preiss, at the western extremity of the principal parallel, and by Mr. Ronald Gunn in Van Diemen’s Land.  It is probable that I may be considered as underrating these additions, when I venture to state them as only between two and three thousand; and that the whole number of Australian plants at present known, does not exceed, but rather falls short of 7000 species.

These additions, whatever their amount may be, confirm my original statement respecting the distribution of the characteristic tribes of the New Holland Flora; some additional breadth might perhaps be given to the principal parallel, and the extent of the peculiar families may now be stated as much greater at or near its western, than at its eastern extremity.

With the vegetation of the extra-tropical interior of Australia, we are now in some degree acquainted, chiefly from the collections formed by the late Mr. Allan Cunningham, and Charles Fraser, in Oxley’s two expeditions from Port Jackson into the western interior, in 1817 and 1818; from Captain Sturt’s early expeditions, in which the rivers Darling, Murrumbidgee, and Murray, were discovered; from those of Sir Thomas Mitchell, who never failed to form extensive collections of plants of the regions he visited; and lastly, from Captain Sturt’s present collection.

The whole number of plants collected in these various expeditions, may be estimated at about 700 or 750 species; and the general character of the vegetation, especially of the extensive sterile regions, very nearly resembles that of the heads of the two great inlets of the south coast, particularly that of Spencer’s Gulf; the same or a still greater diminution of the characteristic tribes of the general Australian Flora being observable.  Of these characteristic tribes, hardly any considerable proportion is found, except of Eucalyptus, and even that genus seems to be much reduced in the number of species; of the leafless Acaciae, which appear to exist in nearly their usual proportion; and of Callitris and Casuarina.  The extensive families of Epacrideae, Stylideae, Restiaceae, and the tribe of Decandrous Papilionaceae, hardly exist, and the still more characteristic and extensive family of Proteaceae is reduced to a few species of Grevillea, Hakea, and Persoonia.