American Pondweed Identification & Treatment
Scientific Name: Potamogeton nodosus Category: Submerged (with floating leaves) Tier: 1 — High-Priority — Most prevalent and/or most damaging across the US
← Back to Plant Identification Guide | Product Cross-Reference | Ecoregion Guide
Identification
American pondweed has two types of leaves: submerged leaves that are thin, narrow, and translucent, and floating leaves that are oval to elliptic, 2–5 inches long, leathery, and borne on long stalks. Floating leaves are often the most visible feature. Small, dense cylindrical flower spikes emerge above the water surface on short stalks. Key distinguishing features:
- Both submerged (thin) and floating (thick, oval) leaves
- Floating leaves are leathery with prominent veins
- Dense cylindrical flower spike above water
- Stems arise from creeping rhizomes rooted in bottom sediment
Commonly confused with: Illinois pondweed (narrower floating leaves), watershield (oval leaves but with gelatinous coating underneath), water lily (much larger floating leaves)
Treatment
Recommended Natural Waterscapes Products:
- Aquathol K or Aquathol Super K (endothall) — Effective contact herbicide for pondweeds.
- Harvester (diquat) — Contact herbicide for quick knockdown.
- Navigate Granular (2,4-D) — Systemic granular for longer-term control.
- Sonar A.S. (fluridone) — Systemic option for season-long management.
Full Profile
- Native Range: Native to North America
- US Distribution: All 48 contiguous states. All EPA ecoregions. USDA Zones 3–10.
- Regulatory Status: Not regulated (native species).
- Habitat: Ponds, lakes, streams, rivers. Grows in 2–8 feet of water. Prefers moderately fertile water.
- Reproduction: Rhizomes, winter buds, fragmentation, and seed.
- Ecological Benefits: One of the most valuable native aquatic plants for wildlife. Pondweed seeds and tubers are a primary food source for dabbling ducks and diving ducks. Excellent fish habitat — provides cover and spawning substrate. Stabilizes sediments. In moderate densities, American pondweed is highly desirable and should be preserved rather than eliminated. Management is only recommended when growth becomes excessive and interferes with recreation or water use.
- Seasonal Behavior: Emerges in spring, peak growth in summer, dies back in fall. Overwinters via rhizomes and winter buds.
Sources: Texas A&M AquaPlant – American Pondweed | USDA PLANTS Database
Related Species
- Hydrilla (Hydrilla verticillata) — Submerged, Tier 1
- Eurasian Watermilfoil (Myriophyllum spicatum) — Submerged, Tier 1
- Duckweed (Lemna minor and related species (L. gibba, L. turionifera, Spirodela polyrhiza)) — Floating, Tier 1
- Watermeal (Wolffia spp. (W. columbiana, W. brasiliensis)) — Floating, Tier 1
- Coontail (Hornwort) (Ceratophyllum demersum) — Submerged, Tier 1
- Water Hyacinth (Eichhornia crassipes) — Floating, Tier 1
← Back to Plant Identification Guide | Product Cross-Reference | Beneficial Considerations
Natural Waterscapes — Expert Aquatic Plant Identification & Treatment Need help identifying a plant? Send us a photo and our experts will identify it for you.