188 PLANTS WHICH HAVE BECOME NATURALIZED IN N. S. W., 



and for the converse state of things in England." The climate and 

 soil differ so much from each other in England and Australia, that 

 one would scai"cely expect many species to be common to both, or 

 that the plants of the one should spring up accidentally amongst 

 those of the other ; and yet it appears, that, whilst Australian 

 plants are cultivated with difficulty in England, English plants 

 find their way hither and nourish; thus showing, that, owing to 

 the absence of long frosty winters and to the rare occurrence of 

 cold drizzling rains, Australia is better adapted to support 

 numerous forms of vegetable life than England. 



In reviewing the list of naturalized plants, it will be found that 

 not more than one-sixth of the whole are monocotyledonous, whilst 

 of the dicotyledonous plants no less than 35 belong to the order of 

 the Composite. With regard to the scantiness of the former, it 

 may be observed, that as we descend in the vegetable kingdom, 

 the species are more Cosmopolitan in their character, or have a 

 wider distribution than plants of a higher organisation. Hence 

 grasses, rushes, and sedges, have many species in common in sub- 

 tropical and temperate countries. Balfour says that " Humboldt 

 and Bonfland, in their ti - avels in equinoctial America, did not see 

 an exogenous plant which was found equally in the New and the 

 Old World ; the only plants which they discovered common to 

 both being some grasses and sedges." As we proceed from the 

 tropics, the greater number of cosmopolitan species are likewise 

 endogens, whilst the introduced species of exogens vary in 

 proportion to the extent of cultivation, the character of the 

 soil, and the nature of their seeds. The Composite order 

 of plants being the most extensive of all orders, and the species 

 being found, though in different proportions, in all parts of 

 the world, it might naturally be expected that many of them 

 Mould find their way to this colony amidst the various seeds 

 imported for the purposes of cultivation. Such has been the case 

 in some instances, but the most troublesome weeds of the oi'der 

 appear to have been introduced accidentally. The seeds of many 

 ( Composites are well adapted for a wide distribution, for whilst the 

 pappus of some species serves as an apparatus for conveying them 



