SOME AMEKICAK COLONISTS. 213 



white claytonia, a straggling round-leaved succulent 

 plant, not unlike the garden purslanes. This queer 

 little tufted trailer, a familiar weed in American gardens, 

 has thickly overrun many parts of Lancashire, having 

 doubtless been landed at Liverpool. In another direc- 

 tion, it has effected an entry by the port of London, and 

 spread in abundance over many parts of Surrey, besides 

 making little excursions up the river to Oxfordshire and 

 attacking several of the neighboring counties on its on- 

 ward march. It is still rapidly advancing ; and though 

 but a naturalized alien, it threatens before many years 

 to become one of our most annoying and persistent 

 garden-weeds. 



A rather pretty American balsam, with orange blos- 

 soms spotted with red, has in like manner made itself a 

 firm local habitation on the banks of the Wey and sundry 

 others among the Surrey streams. Then there is the 

 Canadian Michaelmas daisy, long completely naturalized 

 on the Continent, and now beginning to push its way 

 boldly along the grassy margin of southern English road- 

 sides. All these are thoroughgoing weeds, extremely 

 troublesome in America itself as well as in the European 

 countries where they have established themselves ; and 

 they are rendered dangerous by the fact that they come 

 from a very large continent mainly consisting of open 

 prairie, which insures them excellent weedy constitu- 

 tions, as the final survivors in an exceptionally severe 

 struggle for existence among highly adapted prairie 

 plants. They have come across to us by accident as mere 

 weeds, clinging to the tubers or roots of imported food- 

 plants. Somewhat different is the case of ornamental 

 blossoms like the mimulus, originally planted in flower- 

 gardens, but now fairly established as an escape in boggy 

 or marshy ground. Of these handsome straylings we 



