FLORA OF TASMANIA. [Estimate of Species, etc., 



Estimate of the Australian Flora, and some General Remarks on the Classes and Orders, 

 their Numbers, Distribution, and Affinity. 



I estimate the Flowering Plants known to be indigenous to Australia* at about 8,000 species, a 

 number which will not in all probability be much increased by farther investigations, because it 

 includes upwards of 500 of which I have seen no specimens, and a considerable proportion of which 

 will no doubt prove to be founded on error, and it includes a much larger number which I have 

 reason to beheve will prove to be varieties,t when more of their forms are collected, or themselves 

 more carefully studied. 



About ten years ago (1849), Brown, in the appendix to Sturt's Voyage, estimated the Austra- 

 lian Mora at something under 7,000 species ; since which period 1,000 species have not been added, 

 although the explored area has been greatly enlarged, both by surveys of the tropical coasts, and 

 inland journeys made to the north of the Tropic of Capricorn, and especially by the investigations 

 of Dr. Mueller, during his adventurous explorings of the Australian Alps, and of the northern and 

 eastern parts. Dr. Mueller % himself, who has personally explored more of the continent than any 

 other botanist, except the late Allan Cunningham, considers that the total Flora, including the 

 undiscovered species, Phsenogamic and Cryptogamic (exclusive of the minute Fungi and fresh-water 

 Algce), cannot exceed 10,000 species. Cryptogamic plants are known to be extremely rare in Australia 

 as compared with Phrenogarnic ; nevertheless, as they already amount to fully 2,000 discovered spe- 

 cies^ I suspect that Dr. Mueller's estimate is more probably too low than too high, and that we may 

 assume 9,000-10,000 flowering plants as an approximation to the number that will eventually be 

 found to be indigenous to Australia. || 



Considering that the vegetation of Australia is confined to a belt of more or less fertile land 

 surrounding an arid desert, which occupies perhaps two-thirds of its total area, and that the tropical 

 region is an extremely poor one in plants, this Flora must be considered as very large. ,_ Vnd if"£he 

 tropical Flora is excluded, and the temperate alone compared numerically with that of Europe for 

 instance, the very varied nature of the Australian vegetation will appear all the more remarkable. 

 Thus the superficies clothed with any considerable number of species in extra-tropical Australia, is 

 probably not equal to one-fifth of the similarly clothed area of Europe, which, though so much more 

 varied in all its physical features, contains only 9,648** species, according to Nyman's list, and this 



* Except when otherwise stated, I include Tasmania and its islands under the general term Australia. 



f Dr. Mueller's valuable notes upon my ' Tasmanian Flora,' which will be found in the Supplement, show 

 how very much is to be done in the reduction of species founded on herbarium specimens, even when these are 

 unusually copious and good. 



% Journal of the Linusean Society, Botany, vol. ii. p. 141. 



§ In Tasmania alone there are Ferns and allies, 70 ; Mosses and Hepatica:, 386 ; Algae, 315 ; Lichens, about 

 100 ; Fungi, 275. And I cannot doubt but that this number will be doubled by future discoverers. 



|| I need hardly remark, that the very different opinions entertained by botanists as to what amount and con- 

 stancy of difference between many forms of plants should constitute a species, renders all such comparisons vague ; 

 and I may add that no two or more botanists can ascertain the comparative value of then opinions except they have 

 exactly the same materials to work with. It is too often forgotten that in the sciences of observation what are called 

 negative facts and evidence are worthless as compared with positive. 



** Nyman, Sylloge Florae Europae. 



