AQUATIC PLANTS IN POND CULTURE. 



17 



The water clover {Marsilea quadrifolia) is excellent for shade 

 and shelter, is ornamental, and of early growth. It is objection- 

 able in shallow ponds, however, completely covering the surface to 

 a depth of about 2 feet. 



At this station the limeweed 

 {Chara) is valued as a food pro- 

 ducer, harboring the small forms 

 which are especially good as food 

 for young fish, and as an oxy- 

 genator it is found remarkable. 

 It is fairly good for shelter and 

 as an aquarium plant. 



The spatterdock {Nymphcea 

 advena) is valued chiefly as an 

 ornament and for the shade and 

 shelter it affords. It is also of 

 early growth, but it is a poor food 

 producer on account of its long, 

 smooth stems, which do not pro- 

 vide favorable breeding places for 

 insect larvae or other minute ani- 

 mal life. It is found in 1 to 4 feet ^^^^- is.— Water clover (MarsUea quadri- 

 » , folia). Found along the shores of Bantam 



01 water. Lake, Litchfield County, Conn., whence it 



The loner-leaved pondweed (Po- ^''^ ^^^"^ introduced into various parts of 



^ ^ ^ the country, notably eastern Massachu- 



setts. Native of Europe and Asia. (After 

 Britton & Brown.) 



Fig. 19. — Large yellow pond-lily (Nijmphwa 

 advena). Found in ponds and slow streams. 

 New Brunswick and Nova Scotia to Rocky 

 Mountains, south to Florida, Texas, and 

 Utah. (After Britton & Brown.) 



Calleo also spatterdock. 



Fig. 20. — Long-leaved pondweed (Po- 

 tamogetoti lonchites). Found in ponds 

 and slow streams. New Brunswick to 

 Washington, south to Florida and Cali- 

 fornia. (After Britton & Brown.) 



tamogeton lonchites) does not rank with the two other Potamogetons 

 mentioned here, being but fairly good in any of the important respects. 



