• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar
  • Texas A&M Forest Service
  • Texas A&M Veterinary Medical Diagnostics Laboratory
  • Texas A&M AgriLife Extension Service
  • Texas A&M AgriLife Research
  • Texas A&M College of Agrculture and Life Sciences
AquaPlant
AquaPlantA Diagnostics Tool for Pond Plants and Algae
  • Menu
  • Home
  • Identify a Plant
  • Do I need a permit?
  • FAQs
  • Glossary
  • Videos
  • Online Courses
  • Get Help

Large-leaf Pondweed

Potamogeton amplifolius

Large-Leaf Pondweed Locations in North America
Large-Leaf Pondweed Locations in Southeast US
Large Leaf Pondweed


USDA, NRCS. 2018. The PLANTS Database (http://plants.usda.gov, 28 March 2018). National Plant Data Team, Greensboro, NC 27401-4901 USA.
Illustration: USDA-NRCS PLANTS Database / USDA NRCS. Wetland flora: Field office illustrated guide to plant species. USDA Natural Resources Conservation Service.

What is Large-leaf Pondweed?

Other common spellings and names include: Big-leaved pondweed, Broad leaved pondweed, Broad-leaved pondweed, Large Leaf pondweed, Large-leaved pondweed, and Largeleaf pondweed.

Physical Characteristics

Leaves:

  • Alternate

Submersed Leaves:

  • Bright or dark green
  • Almost see-through
  • 3.15-7.87 inches long
  • 0.79-2.95 inches wide
  • Folded along middle
  • Curved
  • Wavy edges
  • Stalks 0.39-0.79 inches long
  • Many veins (27-49)

Floating Leaves:

  • Often not present
  • Leathery in texture
  • Oval to sword shaped
  • 2-4 inches long
  • 1-2 inches wide
  • Stalks 1.18-4 inches long

Flowers:

  • Small
  • Petal-like lobes
  • 6 to 16 whorls
  • Clustered
  • Spike up from 0.5 to 3 inches long
  • Stalks up to 2-5 inches long
  • 4 petals, sepals, and stamens
  • Above water

Fruit:

  • Small
  • Dry
  • One seeded
  • 0.12-0.2 inches long
  • Flat sides
  • Orange or pinkish when ripe

Stem:

  • Not branching
  • Up to 0.12 inches thick
  • Up to 15 feet long
  • Creeping rhizomes

Roots:

  • Fibrous

Where Does it Grow?

Large-leaf pondweed can be found in slightly acidic, slow-moving streams, rivers, lakes and farm ponds throughout the United States and Canada, but has not been documented in Texas. Compared to other pondweeds, this species can be found in deeper waters.

Pros and Cons of Large-leaf Pondweed

Submerged portions of all aquatic plants provide habitats for many micro and macro invertebrates. These invertebrates in turn are used as food by fish and other wildlife species (e.g. amphibians, reptiles, ducks, etc.). After aquatic plants die, their decomposition by bacteria and fungi provides food (called “detritus”) for many aquatic invertebrates.

How to Manage This Plant
Plant Glossary

Search for a type of plant

2023 Aquatic Webinars

Feb. 24: Ornamental Ponds and Water Gardens

Mar. 21: Selecting Herbicides for Aquatic Vegetation Control

Apr. 18: Pond Stocking 

May 16: Aquatic Plant ID & Management Options

Jun 20: Fish Management Strategies

Email Subscription

Receive updates on upcoming webinars and newly published materials.

Sign Up Now

Hire a Professional Contact Your Ag & Natural Resource Agent Aquatic Plant Nurseries Permissions and Citations Aquatic Herbicide Tables

Bookstore Items

Aquatic Vegetation Identification Cards

Texas A&M AgriLife Extension Service
Texas A&M University System Member

Photo Credits: The majority of the aquatic plant line drawings are the copyright of the University of Florida Center for Aquatic Plants (Gainsville). They are used with permission.

Aquatic plant photographs were provided by David Bayne, Jim Davis, Kelly Duffie, Billy Higginbotham, Michael Masser, John Clayton, Chetta Owens, Diane Smith, Joe Snow, Don Steinbach, Bridget Robinson Lassiter and Peter Woods.

You may use these photos, so long as you give credit to AquaPlant.

  • Compact with Texans
  • Privacy and Security
  • Accessibility Policy
  • State Link Policy
  • Statewide Search
  • Veterans Benefits
  • Military Families
  • Risk, Fraud & Misconduct Hotline
  • Texas Homeland Security
  • Texas Veterans Portal
  • Equal Opportunity
  • Open Records/Public Information