Pondweeds

American Pondweed

Potamogeton nodosus Poir.

Potamogetonaceae (Pondweed Family)

▲ ▼ leaves floating on water, while stems are rooted in sediment

Pondweeds:

U.S native and non-native, creeping perennial, rooted floating plants in the Pondweed Family (Potamogetonaceae) found in ponds and streams
Stems grow up to 6’ long
Most have elongated, linear to elliptical leaves that float flat on water surface
Flower is small, green-gray spike that emerges 3-6 inches above surface for pollination, then sinks back down for seed development
Pondweeds can spread by overwintering buds, seed, rhizomes, fragments
American Pondweed, Variable-leaf Pondweed & Leafy Pondweed are species that should be controlled in Missouri, due to their potential for spreading
Some pondweed species are entirely submerged plants and can be aggressive
- Curled Pondweed is most aggressive
  - Has linear, wavy-edged leaves
- Other species of submerged pondweeds include Leafy pondweed, Sago Pondweed and Large-leaf Pondweed