
AQUATIC PLANTS OF FRESHWATER 

will develop even after the larger plants have been cleaned before intro- 
duction into the aquarium. ‘The dense growth probably acts as a shelter 
for these film-like alga or more secure anchors for their development. 
ANACHARIS 
This mosslike aquatic plant is variously known to botanists as 
Anacharis, Philotria or Elodea and commonly as Waterweed, Ditchmoss, 
Water Thyme, Water Pest and in the British Isles as Babington’s Curse. 
There are 4 or 5 very similar American species ; 
M 'v 7 NEA 
which bloom from May to August, but are also an (i = 
propagated by a plentiful production of off- (NOS iI SSA ai, 
TY hse, bases 
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shoots which, attached or separate, rooted or 
floating, grow with amazing rapidity inany ditch, 
stream or pond throughout the United States 
and North America except the extreme north. 
It is a slender wholly submerged plant with 
fragile jointed and branching stem, 4 inches to 
3 feet long, dependent upon the depth of water, 
so weak that it mats together and decays when 
the water is withdrawn. The male and female 
flowers are borne on separate plants. The pistil- 
late flowers are raised to the surface by their long . 
calyx tubes and the minute staminate flowers 
break off and rise to the surface to shed their 
pollen. The fruit ripens below the surface of 
the water. The plant also forms heavy buds 
in the Fall, which drop to the bottom and 
develop in the following Spring. It is a verit- 
able pest, as it chokes up canals and waterways. 

A nacharis canadensis ( Mich.) 4. alsinastrum 
=" 3 2 FIG. 123. Ditchmoss or Anacharis, 
(Bab.), Fig. 123, 1s the species. most-generally \zcp candle, cise erneene 
to be found and has a weak jointed stem with °°" "ae 
the leaves in whorls of 4’s to 8’s or the lower leaves opposite, linear and 
minutely toothed. The white pistillate flowers develop on calyx tubes 
from 2 to 12 inches long. 
The Common Anacharis 4. canadensis, Fig. 123, thrives fairly well in 
the aquarium, is a good oxygenator, but is so weak and fragile that it will 
easily break into sections. It should be planted in the sand or pebbles in 
groups of 4 to 10 stalks. Freshwater fishes and goldfishes feed upon the 
leaves and in the aquarium frequently entirely destroy the plant. When ~ 
found in cold water streams the plants are more robust and the leaves 
196 
