HIGHER PLANTS 



Brown-leaf or ruffle-leaf pondweed, Potamogeton crispus. — 



Sometimes called the crisp-leaved pondweed, this species has 

 long, very translucent brown leaves with crisped wavy edges 

 (Fig. 62). The flower stalk bears 3 to 10 small flowers and 

 although each flower has both stamens and pistil these do not 

 mature simultaneously so that pollination occurs only when 

 the wind carries pollen from the stamens of one flower to 

 some other one on which the stigmatic surface of the pistil 

 is ripe. 



This pondweed is found in pools and streams, or along lake 

 shores where there is considerable wave action ; in such regions 

 its plants are apt to be dwarfed. They usually grow in water 

 from I to 5 feet deep; sometimes in depths of 7 to 8 feet. 

 They reproduce asexually by means of "burs" or winter 

 buds, sections of the stems which break off, lie over the winter 

 at the bottom and sprout forth new shoots in the spring. 



Occurrence. — Ponds and lakes, often in brackish water, fre- 

 quent or common. Blooms June-July. Massachusetts north 

 to Ontario, south to Virginia. Naturalized from Europe. 



Animal associates. — Larvae of chironomids and the moth 

 Nymphula, and snails are commonly found feeding on its 

 leaves. Wherever pondweeds are abundant they largely 

 support the chironomids which in turn become important 

 fish food. Potamogeton crispus is such a favorite food of wild 

 ducks that game ponds are planted with it. 



Sago pond-weed, Potamogeton pectinatus.- — Like Potamoge- 

 ton natans this is a very common pondweed especially in 

 brackish water. It is one of the earliest to appear in spring, 

 sprouting forth from tubers early in April. The plants grow 

 entirely submerged in a depth of i to 6 feet of water and some 

 of the deep water ones are easily 8 feet long. 



Occurrence. — In slow streams and lake borders often in 

 brackish or limy water. Blooms July-September, Quebec to 

 British Columbia, along the coast to Florida, to Pennsylvania, 

 Great Lakes, Kansas, Colorado. 



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