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VARIABLE PONDWEED 

 (Potamogeton gramineus ; 

 formerly heterophyllus) 



Alaska to Greenland, Cal- 

 ifornia, Iowa and Maryland. 



Underwater leaves are 

 often much longer than in the 

 plant pictured. Sometimes 

 there are no floating leaves 

 (see page 16). 



Resembles Illinois Pond- 

 weed but has smaller leaves 

 and usually is more branched; 

 the stalks of the floating 

 leaves usually are as long as 

 the leaves; and the underwater 

 leaves are stalkless. Resem- 

 bles Red Pondweed but is more 

 branched and has longer- 

 stalked floating leaves with 

 short- tapered or rounded bases. 



ILLINOIS PONDWEED 

 (Potamogeton illinoensis; 

 includes angustif olius and 

 lucens) 



Southern Canada to 

 southern U. S. 



Underwater leaves are 

 sometimes slightly arched 

 lengthwise and sometimes 

 puckered. Sometimes there 

 are no floating leaves 

 (see page 16). 



Resembles Variable 

 Pondweed but has larger 

 leaves; the stalks of the 

 floating leaves usually are 

 shorter than the leaves; 

 and the underwater leaves 

 are often short-stalked. 

 Resembles Bigleaf Pondweed 

 but has underwater leaves 

 that are only slightly 

 arched. Resembles Longleaf 

 Pondweed but has much- 

 shorter-stalked, less- 

 tapered underwater leaves. 



