AQUATIC PLANTS 



57 



bits of velvet connected by a thread. The roots are naturally long for 

 the size of the plant, but fishes usually eat them down to about half 

 length, which interferes with a full development of plant. In the green- 

 house, where they have a moist atmosphere and no interference, they 

 develop with great rapidity. The variety illustrated, Salvinia natans, is 

 native to Europe and is the variety commonly used. 



Although it is claimed that neither Salvinia nor the common wild 

 Duckweed performs any oxygenating function, the author and others 

 have many times seen aquaria completely covered with either of these 

 plants and, with no other plants in the aquarium, the fishes were getting 

 along perfectly well— a state of affairs which would be impossible if the 

 water were blanketed over by an inert substance. 



TRIANEA 

 Trianea bogotensis is an attractive, small floating plant with thick, 

 heart-shaped leaves. It needs a moist warm atmosphere and not too 

 much direct sun. Under these conditions it thrives and is a valued 

 feature in the summer pool or greenhouse tank. It is not found locally 

 in temperate climate, but may occasionally be had of dealers. 



FROGBIT 



Hydrocharis morsus-ranoe, requiring the same conditions as Trianea 

 bogotensis, deserves more attention than it is receiving. Of very pretty 



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| Fig. 46 



"I Frogbit (Life size) 



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