NAIADACE^— PONDWEED FAMILY 



COMMON FLOATING PONDWEED 



Potamogeton nutans 



Potamogeton, Greek, in allusion to the aquatic habit of 

 the genus. 



One of the commonest floating plants upon the quiet 

 waters of ponds and streams throughout the Northern 

 States. July-August. 



Stem. — Twenty to forty inches long, round, hollow, 

 brown, simple or sparingly branched. 



Leaves. — Floating, thick, elliptic, ovate or oval, three 

 to four inches long, one to two inches wide, pointed at 

 apex, rounded or slightly heart-shaped at base, margin 

 entire or wavy; mid vein conspicuous; upper surface dry, 

 green; under surface reddish. Submerged leaves are nar- 

 rowly linear and perish early. 



Flowers. — Small, pink, borne in a dense spike about 

 three-fourths to an inch long, and one-fourth to three- 

 eighths thick. Peduncle terminal, axillary, mucilaginous, 

 thick as the stem, one to two inches long. 



Perianth Segments. — Four, concave, valvate, fitting 

 closely together; really developed connectives at the 

 back of the anthers. 



Stame7is. — Four. 



Pistil.— Oi four carpels which develop into four pitted 

 nutlets. 



Often in midsummer upon the surface of quiet water, 

 rising and falling with the ripple of the waves or the 

 flow of the stream, spreads a group of oblong, rather 



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