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Water-willow (American Water Willow)

Justicia americana

Water Willow Locations in North America
Water Willow Locations in Southeast US
American water willow leaves close up

water willow drawing
full water willow

water willow in water
water willow flower


USDA, NRCS. 2018. The PLANTS Database (http://plants.usda.gov, 28 March 2018). National Plant Data Team, Greensboro, NC 27401-4901 USA.

What is American Water Willow?

Physical Characteristics

  • Up to 3.28 feet tall

Leaves:

  • Linear or sword-shaped
  • Thin at base
  • Up to 6.29 inches long & 0.98 inches wide

Flowers:

  • Spikes up to 1.18 inches long
  • Sepals form a whorl around the petals
  • Sepals about 0.27 inches long
  • Flower violet or white in color
  • 0.39-0.47 inches long

Fruit:

  • Dry
  • About 0.47 inches long
  • Extend farther than the flower

Seeds:

  • 4 seeded
  • Brilliantly polished
  • 0.11 inches long & 0.07 inches wide

Stem:

  • Upright
  • Simple

Roots:

  • Rooting below stem

Where Does it Grow?

American water willow can be found in shallow water and mud.

Pros and Cons of American Water Willow

Deer will browse the leaves; while beaver, muskrat, and nutria will consume the rhizomes of water willow. 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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