AQUATIC PLANTS OF FRESHWATER 



broader, fuller and more pointed than those of quiet or stagnant water, 

 which probably caused it to be considered a different species. It is a 

 very pretty aquarium plant but difficult to maintain in satisfactory condi- 

 tion, except with such fishes as will not molest it, 



Anacharis canadensis gigantea or Elodea canadensis gigantea (Hort.) 

 Fig. 124, is a cultivated species derived from A. canadensis, the most gen- 

 erally distributed native form. It has a thick jointed stem and leaves 



I to 1)4, inches long, in 

 whorls of 4 to 8, with a 

 dense cluster of the long 

 slender leaves at the ends 

 of the stalks. It usually 

 growswithoutmuch branch- 

 ing. In general appearance 

 it considerably resembles 

 Hippuris and is an attrac- 

 tive aquarium plant which 

 grows to a length of 3 to 4 

 feet below and on the sur- 

 face of the water. Its color 

 is a delicate greyish-green, 

 the younger growth usually 

 a bright green, sometimes 

 marked with white. Less 

 fragile than A. canadensis, 

 it is a good oxygenator, of 

 most rapid growth, which 

 thrives with or without 

 roots, set directly in the 

 pebbles or sand or in small 

 pots with soil. May- be 

 had of dealers in aquatic plants. In small aquaria, intended for the pro- 

 pagation of aquarium snails, it is preferable to most of the other aquatic 

 plants. Together with Cabomba it is easiest to be obtained, and is a most 

 satisfactory plant for the novice in aquarium study. 



CERATOPHYLLUM 



This generally distributed aquatic weed, commonly known as Horn- 

 wort,is free-suspended in every stage of development and is shifted in 

 position by every current, though the submerged species of this genus 

 mostly occur in slow streams and still water. Absorption is carried on by 



197 



FIG. 124 Giant Anacharis, Anacharh canandensis gigantea,iion. 

 Reduced one-third. 



