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Blunt-leaved Pondweed

Potamogeton obtusifolius

Last reviewed: August 2026

Blunt-leaved Pondweed (Potamogeton obtusifolius)
Photo: Krzysztof Ziarnek, Kenraiz / Wikimedia Commons (CC BY-SA 3.0)

Toxicity unknown

Blunt-leaved Pondweed (Potamogeton obtusifolius) is not listed by the ASPCA Animal Poison Control Center (opens in new tab) or the other sources we check, so we have no verdict for it either way. Absence from those lists is not a clearance. If your pet shows symptoms after eating any plant, call the ASPCA at (888) 426-4435.

Light

full sun

Water

high

Size

12"–48" H

Bloom

Jun, Jul, Aug, Sep

Native to

CT, ID, MA, ME and 12 more states

Before you buy

Your city may pay you to plant this

Cities and water utilities offer rebates for replacing lawn with native and water-wise plants. We track 445 programs across 44 states, each with a link to the provider and the date we last checked it.

Find rebates in your area

Blunt-leaved pondweed is an aquatic perennial that grows submerged in ponds, lakes, and slow-moving streams. This native water plant produces small flowers on spikes that emerge above the water surface during summer months. It requires permanent standing water to survive and cannot be grown in typical garden soil.

In an HOA neighborhood

Blunt-leaved Pondweed takes more care to keep looking intentional in a front yard. Maintenance level: high. Consider it for backyard or mid-zone beds rather than the street edge.

  • Requires permanent water feature which most HOAs restrict
  • Only suitable for ponds or water gardens
  • Cannot survive in standard landscaping conditions

Wildlife value

This aquatic plant provides important habitat for waterfowl, fish, and aquatic invertebrates. The seeds are eaten by ducks and other water birds, while the submerged foliage offers shelter for fish and amphibians.

Common questions

How much sun does Blunt-leaved Pondweed need?
Blunt-leaved Pondweed grows best in full sun conditions.
When does Blunt-leaved Pondweed bloom?
Blunt-leaved Pondweed blooms in June, July, August, and September.
Where is Blunt-leaved Pondweed native?
Blunt-leaved Pondweed (Potamogeton obtusifolius) is native to CT, ID, MA, ME and 12 more states, per the World Checklist of Vascular Plants (Kew).
Is Blunt-leaved Pondweed HOA-friendly?
Blunt-leaved Pondweed takes more care to look intentional in a front yard. Consider it for backyard or mid-zone beds rather than the street edge.

Native range data from the World Checklist of Vascular Plants (Kew). Pollinator and host plant associations compiled from GBIF, iNaturalist, and published ecological literature.

Ready to grow Blunt-leaved Pondweed? Add it to your garden in Pollinator Patch to track it and get season-by-season care guidance.

Not sure where to start? Take the 2-minute yard quiz