Illinois Pondweed

Potamogeton illinoensis

Also known as: American pondweed, floating-leaf pondweed. 

Also known as: American pondweed, floating-leaf pondweed. 

Illinois pondweed is similar to American pondweed, and can be easily confused. Leaves are oval in shape and float on the surface of the water, and are attached to a long stem.