Water stargrass is dark green to brown with thread-like leaves scattered on flexible, crooked stems that may be up to 2 meters long.  Leaves are similar to those of narrow-leaf pondweed but lack a prominent vein or midrib in the middle.  Water stargrass usually becomes abundant in late summer.  It settles to the bottom in late autumn where it forms a decaying mat in the winter that provides habitat to many small aquatic animals.