65 



be as easily traced. Given a fine climate and a congenial soil, it 

 is easy to predicate of any chance seed or castaway root, that 

 it will speedily germinate and attach itself to its new home. 



But it is a far more difficult task to account for the naturalization 

 of such plants as Lavatera hispida or Trifolium tomentosum — (I am 

 compelled to employ the Latin titles, as they have not yet become 

 common enough to have acquired the dignity of a a local nomencla- 

 ture). The former is a low shrub allied to the common mallow of 

 England ; the latter an insignificant trefoil. That they are aliens 

 in the true sense of the word, we have the authority of Baron von 

 Miiller, and (in the case of Lavatera) of Bentham also, authorities 

 from whom it is pure heresy to difi'er on such a subject as the 

 geographical distribution of plants. Both species ''hail" (as 

 Americans say) from the sunny regions of South Europe ; and 

 where have they chosen to fix their abodes? Lavatera in the 

 islands of Bass' Straits, and Trifolium in the neighbourhood of 

 Circular Head, localities ill adapted (one would suppose) for the 

 reception of two South European plants, conspicuous neither for 

 beauty nor value, and which could scarcely therefore owe their 

 introduction to the hand of man. 



I confess I am quite unable to account for such a phenomenon ; 

 and I will not waste time in mere conjectures. 



I remember, when I was in the United States, some years ago, 

 and was, as usual, indulging my botanical tastes, I used to hear 

 my friends declare, that every one of their most noxious weeds 

 came originally from Great Britain. There is no denying, that 

 there was much truth in the remark; unquestionably a large pro- 

 portion of the plants hurtful to pasture and corn-field had emigrated 

 from the Mother Country. 



Must we too, bring a like accusation against our Alma Mater ? 

 I am afraid we cannot avoid doing so. I believe, that if a sudden 

 blight fell on all the alien weeds of Tasmania, and swept them 

 away, there would be scarcely one vegetable enemy left to interfere 

 materially with the labours of the agriculturist. In fact, I do not 

 know of a single native species vigorous enough to occupy tracts of 

 cultivated land year after year, or to cause serious alarm. 



It would be well if we could say as much for our importations 

 from the old country, and that we had not to lament the introduc- 

 tion of the Briar and the Californian Thistle — not to mention the 

 Spear Thistle and the Milk Thistle, with its pretty marbled leaves — 

 and a host of lesser plagues, such as the Stinging Nettle, and Sheep 

 Sorrel, all of which had much better have remained at home. 



Whether we have to thank Great Britain or, its true home, 

 North America, for that pest of the pond and slow running stream 

 — the American Water Weed — I know not. South Africa has sent 

 us the Cape weed (Cryptostemma), and South America the Bathurst 

 burr. 



The three last named are at present harmless enough ; but I much 

 fear that the day will come when the colony will have bitter cause to 

 regret their importation. 



The Cape weed is not specially hurtful in itself, but as it spreads 

 with great rapidity, it speedily occupies a large area, to the 

 exclusion of grasses and other plants with far more valuable 

 qualities. 



