WHAT IS AMERICAN WEED? 



BY ROBERT BLIGHT. 



IT is Anacharis alsinastrum^ and is commonly spoken of 

 in Great Britain as * ^American weed" and ''Canadian 

 weed." I have frequently heard both names. If Ameri- 

 cans feel any bitterness about the ''English sparrow," 

 they have the satisfaction that they have supplied Eng- 

 land with as troublesome a pest in this water plant. The 

 Treasury of Botany says, (Sub. Anacizaris), "An American 

 plant, which made its appearance in several remote parts 

 of Britain almost simultaneously about the middle of the 

 nineteenth century. How it was introduced is unknown, 

 and it is equally a mystery by what means it traversed 

 the wide tracts of country which separate the various 

 stations in which it first appeared ; for, as it is dioecious, 

 and pistilliferous plants alone have found their way to 

 this country, it perfects no seeds. It easily propagates it- 

 self from a small portion either of the stalk or root, and 

 is of wonderfully rapid growth ; hence it has in many in- 

 stances destroyed the beauty of ornamental pieces of 

 water, impaired navigation in not a few inland canals, 

 and interferes with the working of water mills, by chok- 

 ing the outlets of reservoirs, especially toward the close of 

 summer, when its debris is often brought down by the 

 current in large quantities. Great efforts have been made 

 to eradicate it in various places, but with imperfect suc- 

 cess. It is greedily eaten by swans and some other water- 

 birds ; but even this service is not without its disadvant- 

 ages, since portions of the stem, torn off but not consumed 

 by these seeming allies, are carried away by the current, 

 and transplanted elsewhere." 



H. Noel Humphreys, in "Ocean and River Gardens," 

 1857, is more explicit : "It has been called the New Water 

 Weed, or, by some. Water Thyme, from its slight resem- 

 blance to plants of that class, and its history is somewhat 

 interesting. It was unknown in England so lately as 

 1842, when the late Dr. George Johnston, of Berwick-up- 



