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Waterpepper Smartweed

Persicaria hydropiperoides (Polygonum hydropiperoides)

Waterpepper Smartweed Locations in North America
Waterpepper Smartweed Locations in Southeast US

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 Waterpepper Smartweed?

Physical Characteristics

Leaves:

  • Many
  • Sword-shaped
  • 2-9.5 inches long
  • Up to 2.5 inches wide
  • Fleshy
  • Small at base

Flowers:

  • 2 spikelets over 1.5 inches long
  • Greenish to white or pinkish in color
  • 0.09-0.13 inches long
  • Fleshy on outside
  • 5 lobes
  • 8 stamen

Fruit:

  • Dark brown or black in color
  • Smooth
  • Shiny
  • 0.06-0.13 inches long

Stem:

  • Up to 6 feet long

Roots:

  • Rooting freely at nodes

Where Does it Grow?

Waterpepper smartweed can be found in marshes, wet meadows, streams, ponds and lakes. Sometimes, they form mats in streams.

Pros and Cons of Waterpepper Smartweed

Smartweed seeds are heavily consumed by ducks, small birds, and small mammals. 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.

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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.

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