the Scotch thistle and Bathurst bur, the burs of which are so dangerous to 

 the sheep from their fastening themselves in the wool so firmly as to be 

 removed only with difficulty. 



It remains to be seen whether the altered circumstances of the acclima- 

 tised weeds, which seem to be so favorable to their growth, will prove 

 permanent, or, by an over-stimulation, a change gradually effected in the 

 constitution of the intruders, bringing about degeneracy and subsequent 

 extinction. But such an influence is not yet observable, for they extend 

 farther and farther, and grow just as luxuriantly in the districts whence they 

 spread as far back as from eighteen to twenty-five years. 



Grasses from other countries have also become domiciled in South 

 Australia, which, no doubt, have materially improved the pasture near the 

 coast. 



But not only weeds and grasses, but also cultivated garden plants, 

 perennial and annual, begin to spread and become acclimatised in pasture 

 land. 



It will not, therefore, be uninteresting to give a list of both weeds and 

 other plants naturalised in South Australia, and, as far as possible, the dates 

 and particular circumstances of their introduction, in order, as Sir J. 

 Hooker remarks, to record their increase and migration, and to afford to 

 succeeding observers the means of comparing their future with their present 

 condition. 



DICOTYLEDONS. 



PAPAVERACEAE. 



Common Fumitory. Fumaria officinalis, Dec. A native of 

 Europe, an early introduction : now a troublesome weed in gardens. 



CRUCIFERAE. 



Common Shepherds Burse. CapsellaBursa-Pastoris, Moeneh 

 and Caps., procumbens, Fr., both well known European weeds. Have been 

 in the colony for the last thirty years, and have spread with rapidity, 

 especially in abandoned places and on roadsides. 



Hedge Mustard. Sisymbrium officinale, Scop. A native of 

 Europe. Has found its way probably from Tasmania, and is now abun- 

 dant on roadsides and in waste places. 



