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dulacea, or Cape-weed, which, like the clover-burr, fairly smothers- 
out of existence native annuals and perennial grasses; its 
abundantly produced seeds germinate with the first fall of rain, 
and the plant grows very rapidly and vigourously. An indi- 
vidual of this procumbent species will often cover a space of 
30 inches in diameter, but commonly such exuberant growth is 
on ground where the surface has been broken by cultivation or 
otherwise. 
Other examples of introduced plants, which take complete 
possession of the soil, often covering acres, especially where it is 
very rich, are afforded by various species of the thistle-tribe, and 
several other European composites have also become very 
common. Amongst the numerous shrubby plants which threaten 
to displace the Australian indigenes, none are more noteworthy 
than the sweet-briar (Rosa rubiginosa), and the dog-rose 
(Rf. canina), which on neglected properties take complete posses- 
sion, and are difficult to eradicate. In the coldest and moistest 
parts of Australia the Bramble (Rubus fruticosus) is already 
forming tangled brakes as impenetrable as the masses of furze or 
whin (Ulex europeus) to be found under the same conditions. 
A full list of introduced plants would include a large proportion | 
of small or of no economic value. 
The destructive effects of settlement upon the indigenous flora 
of Australia is nowhere more apparent than in the purely pas- 
toral districts where the rainfall is decidedly scanty. Through- 
out the immense region known as Riverina, and to the extreme 
western and northern runs of South Australia, the injury to the 
original vegetation by overstocking has assumed so great a mag- 
nitude as to entail a national loss. Continuous overstocking has 
destroyed the bushy vegetation and the perennial grasses. The 
numerous species of Atriplex, Kochia, Rhagodia, and other Salso- 
laceous plants, Mesembrianthemum, and a long list of other small 
shrubs, together with the smaller tree-growths of various Acacias, 
Myoporum, &c., which formerly provided abundant sustenance 
for sheep and cattle during ordinary droughts, have now disap- 
peared, and only inedible shrubs, mostly of the Proteaceus order, 
remain. The effects of this destruction had begun to be felt at 
each period of drought more and more, and now the rabbit-plague 
comes to finish the devastation begun by injudicious stocking, so 
that throughout the territories above mentioned hundreds of square 
miles are to be found which (except during favourable seasons 
when the rainfall is sufficient for the growth of annual grasses 
and herbs) have ceased to carry stock. Indeed, for miles back 
from the river frontages, and in the neighbourhood of wells and 
dams, an unproductive surface, trodden down until almost im- 
pervious to water, now extends. Hence, from the diminished 
