AQUATIC PLANTS IN POND CULTURE. 9 



aquarium plant. It is found in 2 to 4 feet of water, extending to 

 but not above the surface. 



The slender naias {Naias flexilk), which is a good food producer, 

 is good for shelter, is regarded as a fair oxygenator, is somewhat 

 ornamental, and is a fairly good aquarium plant. 



The six plants so far mentioned have been listed in the order of 

 esteem as held by the superintendent of the Fish Lakes. The 

 remainder of the list for this station does not follow any par- 

 ticular order, but, as before, the good or bad qualities the super- 

 intendent believed the plants to possess are noted in each case. 



The waterweed (Philotria canadensis) ^ which grows in 2 to 4 feet 

 of water, extending to, but not above, the surface, is a good food 

 producer and a good oxygenator, is good for shelter, and is valuable 



F^G. 11. — Needle spike-njsh (Eleochans 

 acieularUf). Found in wet soil 

 throughout North America, except in 

 extreme north. Also in Europe and 

 Asia. (After Britton. & Brown.) 



Fig. 12. — Tuberous white water lily 

 (CaxtalM tuberosa). Lake Champlain 

 west through Great Lakes to Michigan, 

 south to Trenton, N. J., Meadeville, 

 Pa., and eastern Nebraska. (After 

 Britton & Brown.) 



for its early growth. It also luakes a good aquarium plant, but is 

 dangerous in ponds, however, owing to its dense growth. 



Water stargrass {Fleteranthera duhia) has the same merits as the 

 watei-weed, being a good food producer, fair oxygenator, and excel- 

 lent for the shelter it affords and for its early gi^owth. It is found 

 in water 1 inch to 4 feet deep. 



Tlie needle spikerush {Eleocharis acicularis) is of very little value 

 except for its early growth. The fine, smooth culms are very easily 

 cleaned by the large-mouthed black bass, which cast their spawn 

 upon them. 



One of the water lilies {CastaUa tuherosa)^ which furnishes shade 

 and shelter, is ornamental and of value because of its early growth. 

 It serves as a good protection to young fish from predacious birds. 



Floating heart {Limnantheminn nymphoeoides)^ although but 

 fairly good as a food producer, is excellent for shade, shelter, and 

 ornament and is fairly hardy. 



