U. S. B. F.—Doc. 826. 
PLATE VII. 
Fic. 1.—Spiked water milfoil (Myriophyllum 
spicatum). Found in deep water. New- 
foundland to Manitoba and the Northwest 
Territory, south to Florida, Iowa, Utah, 
and California. Commonly known as fox- 
tail. Suited to southern ponds of high 
temperature, and unlike most species will 
thrive in comparatively soft waters. 
* Parrot-feather,’”’ and introduced species 
of Myriophyllum will make better growth in 
sterile ground than the foxtail; otherwise 
the two have similar characteristics. 
Fic. 2.—Hornwort (Ceratophyllum demersum). 
Found in ponds and slow streams through- 
out North America, except extreme north. 
This plant is shallow-rooted, deriving most 
of its sustenance from the water. Will 
thrive in cold spring water. 
Fig. 3.— Fanwort (Cabomba  caroliniana). 
Found in ponds and slow streams, southern 
Illinois to North Carolina, south to Florida 
and Texas. Characteristics similar to Cera- 
tophyllum, 
Fie. 4.—Chara fragillis. A common form of 
chara. There are many varieties of this 
species and all are classed very high as 
food producers and oxygenators. Grows 
profusely in all limestone waters through- 
out the United States, 
