Watercress Identification & Treatment
Scientific Name: Nasturtium officinale Category: Emergent Tier: 3 — Localized — Naturalized, sometimes invasive
← Back to Plant Identification Guide | Product Cross-Reference | Ecoregion Guide
Identification
Watercress has small, rounded, dark green compound leaves arranged alternately on trailing, hollow stems. Small white four-petaled flowers bloom in clusters. The plant has a distinctive peppery flavor and is commonly found in and along streams and springs. Key distinguishing features:
- Small, rounded compound leaves (3–9 leaflets)
- Trailing, hollow stems rooted at nodes
- Small white 4-petaled flowers in clusters
- Peppery taste and aroma when crushed
Commonly confused with: Dollar Weed/Pennywort (single round leaves, not compound), Creeping Water Primrose (yellow flowers, not white)
Treatment
Watercress can clog small streams and spring-fed areas. Mechanical removal is generally preferred.
- Mechanical removal — Hand pulling or raking is effective and preferred.
- Glyphosate 5.4 — Foliar application to emergent growth where mechanical removal is impractical.
Important: Watercress often grows in flowing water that feeds ponds. Herbicide use upstream should be carefully considered to avoid affecting downstream ecosystems.
Full Profile
- Native Range: Europe and Asia
- US Distribution: Naturalized throughout the United States. USDA Zones 3–11.
- Regulatory Status: Considered invasive in some states, particularly where it displaces native vegetation.
- Habitat: Springs, streams, spring-fed ponds, and ditches with cool, clear, flowing water.
- Reproduction: Stem fragments root easily. Also spreads by seed.
- Ecological Benefits: Provides some nutrient uptake and cover for invertebrates. Edible and has historical culinary value, though wild watercress near livestock should not be consumed due to parasite risk.
Sources: USDA PLANTS Database | USGS NAS
Related Species
- Creeping Water Primrose (Ludwigia spp.) — Emergent, Tier 1
- Dollar Weed (Pennywort) (Hydrocotyle spp.) — Emergent, Tier 2
- Parrot Feather (Myriophyllum aquaticum) — Emergent, Tier 2
← 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.