ON THE 



AND OTHEE PLANTS IN SOUTH AUSTRALIA, 



It is an historical fact that whenever man settles in a new country he 

 not only carries the weeds that are most troublesome in cultivated ground 

 along with him, but he also exercises a potent influence over the indigenous 

 vegetation, especially when he engages in agricultural and pastoral pursuits. 

 The plough, the axe, the flocks and herds, are enemies to the existing 

 vegetation, and as cultivation advances each representant of the herbaceous 

 flora, perennial and annual, succumbs to the foreign influence. But the 

 plough, axe, and herds are not the sole destroyers of the native herbage, for 

 with cultivation are introduced noxious weeds, and the new-comers, finding a 

 suitable soil and climate, spread with alarming rapidity, and become possessors 

 of the ground, ejecting the indigenous herbaceous plants, and taking their 

 places. 



From the past and present constant intercourse with Europe and other 

 parts of the world, and the abundant importation of seeds into Australia for 

 agricultural and horticultural purposes, it is no wonder that a very great 

 number of the weeds most troublesome at home are now naturalised in South 

 Australia. 



Our temperate climate and soil suit their growth, and such atmospheric 

 influences, as hot winds, unseasonable, &c., do not check their spread. 

 Another cause of their extension is to be found in the extent of un- 

 occupied ground, which is alone sufficient to account for the predominance 

 and migration of so many of the worst European weeds. Some of these, 

 viz. : The Cockspur, Centaur ea melitensis, Linn.; the Bathurst bur, Xanthium 

 spinosum. Linn. ; the Scotch thistle, Onopordon Acanthiitm, Linn. ; the Varie- 

 gated thistle, Carduus Marianus^ Linn. ; the Stinkaster, Inula stiaveolens, Jacq. ; 

 the Sheep weed, Lithospermum arvense, Linn. ; and the Cape dandelion, 

 Cryptostema calendulacea, R. Br., already cover immense tracts of pasture 

 land, and extend farther and farther to the destruction of the native herbage. 



Notwithstanding that thousands of pounds have been expended legisla- 

 tion has not succeeded in extirpating the most troublesome of intruders, viz., 



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