68 THE FLORA OF SOUTH AUSTRALIA. 
of hitherto undiscovered plants will be but little less here than in Van 
Diemen's Land, or in a corresponding area of New South Wales, al- 
though for the same space in Western Australia, we must assume 
3000 species. 
In these different parts of the country, the water-plants more es- 
pecially correspond ; then the shore- and meadow-plants; and among 
them more Monocotyledons than Dicotyledons, till at last, among the 
more simply organized Acotyledons we meet only (or nearly so) with 
species which belong at the same time to a great part of the earth. 
It is further worthy of remark, that we are sufficiently indemnified 
by the variety of forms, for the acknowledged paucity of plants, in 
comparison with the vegetation of Western Australia; sinee 1168 true 
Cotyledonous plants, which I have hitherto found within the limits 
of this Colony, are divided into 452 genera and 99 Natural Orders, 
whilst there, 2000 species are referable to only 430 genera and 91 
` families ; in which calculation, as also in the former omone the 
imported plants are not taken into account. : 
After these general considerations we will endeavour to exhibit, i ina 
few brief touches, the picture of the landscape, as far as it depends on 
the grouping of plants. But as within the limits of this sketch I am 
unable to develope the proportions with more than proximate com- 
pleteness, so in like manner I must frankly admit that, owing to the 
gradual blending together of the groups of vegetation, and the fre- 
quently sudden extinction of species, I have not always been able to 
succeed in assigning even to the principal forms, which could alone be 
taken into account, their most appropriate station; but since I have 
hitherto been able to meet with scarcely any delineations of the 
vegetable kingdom from this point of view, this sketch may suffice for 
the present, as a basis for future labours. à 
The coast-border of South Australia is formed either of a muddy 
alluvial land, of sandy plains, or of a rockly upland, of which the last 
is almost wholly denuded of vegetation, while the plants of the other 
parts do not differ materially from the common shoré-flora of extra- 
tropical Australia. The noble Avicennia, a pioneer of the vegetable | 
kingdom, borders the sea-shore here, as in most countries of the 
eastern hemisphere, and forms, with a Melaleuca and Myoporum in- 
sulare, both following the channels of the coast, the only trees. In 
richer abundance however along the muddy low grounds, which have 
