INTRODUCTION. 25 



constantly need the aid of man to secure and maintain a 

 foothold. Such is the case. The weeds of those days 

 were obliged to adapt themselves to the most hostile 

 conditions. If they could not do this, they lingered on 

 year by year wherever they could maintain a foothold, 

 and then almost disappeared from the flora of the Island. 

 Consequently these weeds were largely of native origin, 

 and not many in number. 



But within a few years a new state of things has arisen. 

 Not only have the old weeds been gaining a stronger and 

 stronger foothold, but additions to the list are reported 

 every year, chiefly at Bar Harbor or in its neighborhood, 

 whence they spread to other parts of the Island. Only a 

 few years ago such common weeds as Portulaca oleracea, 

 Amarantus retroflexus and A. albus, Medicago lupulina, 

 Lepidium Virginicum.^ Mollugo verticillata, and Plantago 

 lanceolata were either unknown or so rare that it was diffi- 

 cult even to secure specimens of them. They are now 

 becoming more and more common, and appearing slowl}' 

 but surely throughout Mt. Desert. Some of these obtain 

 their foothold through cultivation of the soil, and all seem 

 to come, as many people do, because it is the fashion, 

 taking advantage of the increased means of introduction 

 afforded by the importation of foreign seed, of foreign 

 soil with other plants, of hay, and of the various other 

 methods by which weeds travel about from place to place. 



This explanation, it is hoped, will show why so many 

 of the common weeds find no place in this Catalogue. It 

 also shows that at any time such additions to the flora 

 are likely to be reported by any botanist who happens to 

 examine the waste and cultivated grounds and the way- 

 sides of the constantly growing villages and settlements. 

 Of these newcomers it will be well to ascertain and note 

 carefully the date of introduction. 



