Flower profile
American water-willow
Justicia americana
American water-willow (Justicia americana) is a flowering plant in the Acanthaceae family, native in the lower 48 states, blooming mostly May–July across the U.S.
American water-willow is a wildflower that USDA PLANTS lists as native in the lower 48 states. In Arkansas it's most often seen in bloom in May–July.
*iNaturalist research-grade observations, as of October 17, 2026.
On our lists for: Arkansas
Quick look
Dianthera americana, commonly known as the American water-willow, is an herbaceous, aquatic flowering plant in the family Acanthaceae. This perennial species is native to North America, and can typically be found in abundance throughout the eastern half of the continent along shorelines, in lakes or ponds, or in the shallow riffles of streams and rivers.
- It belongs to the Acanthaceae family. iNaturalist
- USDA PLANTS describes it as an herb (forb) with a perennial life cycle. USDA PLANTS
- USDA PLANTS lists it as native in the lower 48 states and records it in 28 states. USDA PLANTS
- NatureServe lists it as native to Arkansas. NatureServe
- In Arkansas, most iNaturalist sightings of it in flower come in May–July. iNaturalist
- USDA PLANTS lists its flower color as white. USDA PLANTS
- USDA PLANTS gives its bloom period as late spring. USDA PLANTS
- USDA PLANTS lists a mature height of about 2.5 ft. USDA PLANTS
- iNaturalist has 650 research-grade sightings of it in Arkansas, ranking #78 among the 170 flowers on our Arkansas list. iNaturalist
When does it bloom?
In Arkansas, most flowering sightings come in May–July.
Conservation status
- Federal (U.S. ESA)
- Not listed Not listed under the Endangered Species Act. USFWS ECOS does track it with the label “Resolved Taxon,” which is informal and gives no legal protection. USFWS ECOS
- NatureServe global
- G5 Secure worldwide. NatureServe
- Arkansas
- No list Arkansas has no state law listing endangered or threatened plants, so we show NatureServe's Arkansas ranks instead. NatureServe: SNR, not yet ranked in Arkansas.
- Rare elsewhere
- Other states where NatureServe ranks it rare or missing: IA (S1), LA (S2), MI (S2), VT (SX). (S1 critically imperiled, S2 imperiled, SH possibly extirpated, SX presumed extirpated.)
Checked October 17, 2026. Rankings and lists can change, so follow the links for the latest.
Can you eat it?
None of the sources we checked (NC State Extension (no edibility or poison notes on its page), USDA PLANTS) say whether it's edible or poisonous for people. NC State Extension
It isn't on the ASPCA plant list, and NC State Extension doesn't flag it for pets.
🌿 Never eat a wild plant unless you're certain of its ID; this isn't medical advice. Worried about a person? Call Poison Control at 1-800-222-1222. Worried about a pet? Call your vet.
Where does it grow?
USDA PLANTS records American water-willow in 28 states plus Washington, D.C.
recorded by USDA PLANTS on our state lists not recorded
See the full list of states
Alabama, Arkansas, Delaware, Florida, Georgia, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maryland, Michigan, Mississippi, Missouri, New Jersey, New York, North Carolina, Ohio, Oklahoma, Pennsylvania, South Carolina, Tennessee, Texas, Vermont, Virginia, West Virginia, Wisconsin; District of Columbia.
Arkansas counties with USDA records: Baxter, Benton, Bradley, Carroll, Clark, Cleburne, Conway, Crawford, Drew, Faulkner, Franklin, Fulton, Garland, Hot Spring, Howard, Independence, Izard, Johnson, Logan, Madison, Marion, Mississippi, Montgomery, Newton, Ouachita, Perry, Pike, Polk, Pope, Pulaski, Randolph, Saline, Scott, Searcy, Sebastian, Sharp, Stone, Van Buren, Washington, White, Yell.
Growing conditions
USDA PLANTS gives American water-willow a low shade tolerance, low drought tolerance and medium moisture use. It is rated for soil pH 5.4 to 7.6 and winter lows down to -28 °F.
- Shade tolerance
- Low
- Drought tolerance
- Low
- Moisture use
- Medium
- Soil textures it is adapted to
- coarse, medium, fine
- Soil pH range
- 5.4 to 7.6
- Minimum temperature tolerated
- -28 °F
- Frost-free days needed (minimum)
- 140
- Annual precipitation range
- 35 to 60 inches
- Minimum root depth
- 10 inches
- Salinity tolerance
- None
- Fertility requirement
- Low
- Growth rate
- Rapid
- Active growth period
- Spring
- Fruit or seed
- Brown · Spring to Fall
- Can be propagated by
- bare root
- Commercial availability
- Routinely Available
From the USDA PLANTS characteristics data for JUAM. USDA ratings are general guidance for the species, not a guarantee for your garden.
Names, range and relatives
Native status by region (USDA PLANTS): Canada: Native; Lower 48 states: Native.
Other scientific names (synonyms in USDA PLANTS): Dianthera americana, Justicia mortuifluminis, Justicia umbratilis.
County records: USDA PLANTS lists it in 764 counties across 26 states; the most are in Missouri (85), Kentucky (71), Virginia (69).
Other Justicia on Bloomipedia (2): Chuparosa, Squirrel's tail.
More from the Acanthaceae family (12 on Bloomipedia; most observed first): Carolina ruellia, Hairy ruellia, Mexican ruellia, Common wild petunia, Black mangrove, Chinese violet, Thurber's desert honeysuckle, Coral creeper.
More Arkansas flowers
Sources
- USDA, NRCS. PLANTS Database, profile JUAM.
- iNaturalist, Justicia americana: taxonomy, research-grade observation counts and “Flowering” annotations, retrieved October 17, 2026.
- Wikipedia, Dianthera americana (lead quoted under CC BY-SA 4.0).
- Arkansas: Arkansas State Plant Board noxious weeds and prohibited plants (2 CAR § 50-101).
- USFWS, ECOS species database (ESA listing check), October 17, 2026.
- NatureServe Explorer, Justicia americana (global and state ranks).
- Edibility and toxicity: NC State Extension.
- Photo: Ken-ichi Ueda via iNaturalist · CC BY 4.0 · resized.