AQUATIC PLANTS IN POND CULTURE. 13 
The wild celery, or eel grass (Vallisneria spiralis), is found to bea 
good oxygenator, and is a desirable plant because of its early growth. 
It is also good for shade and shelter, and is an excellent aquarium 
Fic. 7.—Wild celery, or eel-grass (Vallisneria spiralis). In quiet waters, New Brunswick 
to Florida, west to Minnesota, Iowa, and Texas. (After Britton & Brown.) 
plant. It is found in 2 to 4 feet of water, extending to but not above 
the surface. 
Fic. 8.—Slender Naias (Naias fierilis). Found in ponds and streams throughout nearly all 
North America, (After Britton & Brown.) 
The slender Naias (Vaias flexilis), which is a good food producer, 
is good for shelter, and is regarded as a fair oxygenator, is somewhat 
ornamental and a fairly good aquarium plant. 
