404 PLANT CULTURE 



afforded. When the plant shows signs of going back take it out of 

 the pot and wash most of the soil from the roots; give fresh soil, 

 moderately rich, and replace it under water. Plants which have 

 been growing for some time usually have several crowns. It does 

 not do the plant any harm in the least to wash the soil from every 

 part of the roots and divide it into several pieces, placing each 

 part in 4-inch pots. Its greatest enemies are the lower forms of vegeta- 

 tion which cling to the leaves. To check these, keep the plant in 

 total darkness for a few days. 



Propagation. By division, and from seeds. 



AZOLLA. A. caroliniana is a floating aquatic closely allied to 

 Salvinia naians. The plants are very small, but increase very rapidly 

 when growing on the surface of the water. In water of a tempera- 

 ture above 60 degrees F. the plants are bright green, but in lower 

 temperatures they are partly of a reddish tinge. They should be 

 wintered in water out of the reach of frost. They are useful for 

 aquariums. 



CABOMBA (Fish Grass). For the aquarium and small pool 

 C. caroliniana is, perhaps, as commonly used as any plant. Dealers 

 sell bunches of cuttings which only last a few weeks unless placed 

 in soil. Unlike the Myriophyllum, the Cabombas are entirely sub- 

 merged. They act as purifiers for the water in fish globes. 



EICHHORNIA (The Water Hyacinth). Eichhornia crassipes 

 may be utilized as a most attractive tub plant in the following man- 

 ner: Put, say, three plants in as many s-inch pots of rich soil; fill 

 a tub with water and sink the pots just under the surface. Beyond 

 wanting water to replace that lost by evaporation they will take 

 care of themselves; the surface will become a thick mass of plants, 

 with fresh flowers opening every morning. Although this plant 

 floats on water naturally, without the roots being fixed in soil, it 

 also flourishes in saturated ground at a surprising rate, keeps a 

 fresh, green appearance, and produces myriads of flowers; it is well 

 worth a trial for unsightly marshy spots. E. azurea is an interesting 

 relative of the above, with darker colored flowers. It is useful for 

 planting around the margins of ponds, covering quite a large water 

 surface during a Summer's growth. Both species are easily kept 

 over Winter by placing a few on the surface of a warm tank. The 

 Eichhornias have become a pest in St. John's River, Fla., where 

 they have grown so abundantly as to make the river unnavigable, 

 but there is no danger of its becoming a pest in the North. 



