Coontail (Hornwort) Identification & Treatment
Scientific Name: Ceratophyllum demersum Category: Submerged Tier: 1 — High-Priority — Most prevalent and/or most damaging across the US
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Identification
Coontail is a rootless, submerged plant that floats freely or is loosely anchored in bottom sediments. Leaves are stiff, forked (dichotomously branched), and arranged in dense whorls around the stem. The leaves are more closely spaced near the branch tips, giving the ends of the stems a bottlebrush or raccoon-tail appearance. Key distinguishing features:
- No true roots — floats freely or loosely anchors
- Stiff, forked leaves in whorls
- Dense leaf clusters at stem tips (bushy "coontail" look)
- Leaves feel rough due to small teeth along margins
Commonly confused with: Watermilfoil (feather-like leaves, not forked), bladderwort (has small bladder traps on leaves), elodea (simple leaves, not forked)
Treatment
Recommended Natural Waterscapes Products:
- Aquathol K (endothall) — Effective contact herbicide for coontail. Aquathol K
- Aquathol Super K (endothall granular) — Granular formulation for targeted spot treatment. Aquathol Super K
- Harvester (diquat) — Contact herbicide; effective for quick knockdown. Harvester
- Sonar A.S. (fluridone) — Systemic option for season-long control in closed water bodies. Sonar A.S.
Full Profile
- Native Range: Native to North America (cosmopolitan worldwide)
- US Distribution: All 50 states, all EPA ecoregions. USDA Zones 3–11.
- Regulatory Status: Not regulated (native species).
- Habitat: Lakes, ponds, streams, rivers, ditches. Tolerates a wide range of conditions including low light, moderate current, and variable nutrient levels. Can grow in deeper water than most submerged plants (up to 20+ feet).
- Reproduction: Fragmentation and vegetative growth. Does not produce tubers. Seeds are rare and not considered a significant reproduction method.
- Ecological Benefits: Excellent fish habitat — the dense branching structure provides cover for juvenile fish, invertebrates, and zooplankton. Oxygenates water through photosynthesis. Provides food for waterfowl (coots, ducks). Serves as an important native component of balanced aquatic plant communities. In moderate amounts, coontail is desirable.
- Seasonal Behavior: Grows actively spring through fall. Overwinters as dormant stem fragments in colder regions. Can persist year-round in warmer climates.
Sources: Texas A&M AquaPlant – Coontail | USDA PLANTS Database
Related Species
- Hydrilla (Hydrilla verticillata) — Submerged, Tier 1
- Eurasian Watermilfoil (Myriophyllum spicatum) — Submerged, Tier 1
- Curly-Leaf Pondweed (Potamogeton crispus) — Submerged, Tier 1
- Elodea (Common Waterweed) (Elodea canadensis) — Submerged, Tier 1
- Egeria (Brazilian Elodea) (Egeria densa) — Submerged, Tier 1
- Sago Pondweed (Stuckenia pectinata (formerly Potamogeton pectinatus)) — Submerged, Tier 2
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