Potamogeton lucens, or shining pondweed, is an aquatic perennial plant native to Eurasia and North Africa. It grows in relatively deep, still or slow-flowing, calcareous freshwater habitats.
(Wikipedia)
Potamogeton illinoensis, commonly known as Illinois pondweed or shining pondweed, is an aquatic plant. It provides food and cover for aquatic animals.
(Wikipedia)