This is an advanced form of algae often mistaken as a submerged flowering plant. It is often called muskgrass or skunkweed because of its foul odor. It is a gray-green color, has no flowers and will not extend above the water surface. It has a grainy or crunchy texture and cylindrical whorled branches with 6-16 branchlets around each node.
Concern: It grows very rapidly and can take over a lake or pond if left untreated. If it takes over it can cause problems for fish habitat, boating and swimming.