Pondweeds are perennials with underwater leaves scattered on long (to 6 feet), flexible, jointed stems that are rooted to the bottom. Some also have floating leaves that are different from the submerged ones. Among the species, the leaves range from large, round, and leathery to small, needlelike, and delicate. The small, greenish flowers are borne on a spike that extends above the water for wind pollination, then sinks below the surface. Pondweeds can spread by rhizomes (modified underground stems), winter buds, seeds, or fragmentation (“cuttings”), depending on the species.
Missouri has about 10 species of pondweeds. Potamogeton, the genus name, is pronounced “PO-tuh-mo-GHEE-tun.”