Illinois pondweed I llinois pondweed is a common submersed plant.
Illinois pondweed grows equally well in swift-flowing rivers or quiet lake margins.
The submersed leaves are about the same size, but are more lance-shaped. Submersed leaves have pointed tips and pointed bases. Illinois pondweed's greenish flowers are on spikes that are one to three inches long. Other Pondweeds T here are about 80 species of pondweeds in the world. They occur in a variety of aquatic habitats.