ELEVEN IMPORTANT WILD-DUCK EOODS. 



23 



which have been thought to represent distinct species, may be largely 

 due to conditions under which the plants were grown. 



Water-weed has had various scientific names applied to it, and the 

 following may be encountered in trade catalogues: Philotria, Elodea, 

 and Anacharis. The specific name that has been most commonly 

 used in this country is canadensis. Dealers in aquarium plants usually 

 list a form of water-weed known as Anacharis canadensis gigantea. 



Fig. 20.— Water-weed. A diffuse form. 

 DISTRIBUTION. 



Water-weeds grow naturally throughout most of North America. 



PROPAGATION. 



Water-weed propagates itself from pieces of leafy stem or root. It 

 is tenacious of fife, and if shipment in good condition is achieved, no 

 trouble will be experienced in obtaining a stand of the plant. Bury 

 the roots or bases of stems in the bottom in shallow water for quick 

 results. The plant will grow, however, if only thrown in water 

 shallow enough (3 feet or less) to allow it to send roots to the bottom. 

 It likes a loam or sandy loam and does not grow in clay. Either still 

 or running waters are suitable. When established it will spread to 

 water up to 10 feet in depth. 



