
AQUATIC PLANTS OF FRESHWATER 

POTAMOGETON 
About 40 species and sub-species of Potamogeton, also known as 
Channel, Pond or Riverweed, the latter from the Greek significance of 
the botanical name, are native of North America. hey are all weedy 
plants which attach themselves to the bottom of ponds, shallow lakes, 
streams and canals and grow so luxuriantly as to choke the waterways. 
They are also known as Stink-grass on account of the rank fetid odor of 
the plant when exposed to the sun on the banks or shore. In many of 
the species there are two kinds of leaves, the narrow submerged and the 
broader floating leaves, which surround the small green flowers consisting 
of 4 stamens and usually 4 one-ovuled ovaries. The fruit is a small nut- 
let containing a coiled or hooked embrio. Four species have come into 
slight notice in American water gardens. 
Potamogeton crispus (Linn.) or Curled-leaved Pondweed, Fig. 128, has 
a dark green stem and beautiful dark olive-green, two-ranked serrulate 
and crisped linear leaves with a compound midrib and the outer nerves 
near the margins. The ovoid fruit has a small embrio with its apex 
pointed directly towards the base, and the peduncle or stem recurved on 
the fruit. It occurs generally in fresh, brackish 
and salt water from Massachusetts to Pennsyl- 
vania and in Virginia, and flowers in August. 
Potamogeton lanceolata (Linn.) or Spear- 
leaved Channelweed or Pondweed, Fig. 128, is 
generally distributed in all running and stagnant 
waters, forming thick almost impenetrable mats 
that obstruct the streams; and, as it is one 
of the fragile species, it often occasions the stop- 
page of turbines and water-wheels, especially in 
the late fall when it sheds its foliage. In this 
species the winter buds may be readily recognized. 
The flowers appear in July and August and 
consist of a cluster of tiny green pedals about a 
thick scape and the fruit is a hard nutlet with 
one or sometimes two grooves on the back; the 
embrio forming a spiral of one and a half turns. 
Native in almost all parts of the United States 
and North America. 
Potamogeton natans (Linn.) or Common 
FIG. 128. Curled-leaved Pond- Spade-leaved Floating Channelweed or Pondweed, 
weed, Potamogeton crispus; and 
Spear-leaved Pondweed, Potamoge- Fig, 129, has long and almost leafless stems with 
ton lanceolata, with winter bud. : 
Reduced. one-third: short narrow pointed submerged leaves, rounded 

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