Host an Event Volunteer Join Tickets

Support the plant database you love!


Plant Database

Search for native plants by scientific name, common name or family. If you are not sure what you are looking for, try the Combination Search or our Recommended Species lists.

Enter a Plant Name:
Or you can choose a plant family:
Justicia americana (American water-willow)
Livings, Hal

Justicia americana

Justicia americana (L.) Vahl

American Water-willow, Water-willow

Acanthaceae (Acanthus Family)

Synonym(s): Dianthera americana, Dianthera americana var. subcoriacea, Justicia americana var. subcoriacea, Justicia mortuifluminis, Justicia umbratilis

USDA Symbol: juam

USDA Native Status: L48 (N), CAN (N)

An aquatic with bicolored flowers in dense, head-like or spike-like clusters on long slender stalks rising from leaf axils.

This colony-forming plant has underground stems. Loose-flowered Water-willow (J. ovata), a similar species found from Virginia south to Florida and Alabama, has more loosely flowered spikes.


From the Image Gallery

37 photo(s) available in the Image Gallery

Plant Characteristics

Duration: Perennial
Habit: Herb
Root Type: Fibrous
Leaf Retention: Deciduous
Leaf Complexity: Simple
Leaf Shape: Linear
Leaf Venation: Pinnate
Leaf Pubescence: Glabrous
Leaf Margin: Entire
Leaf Apex: Acuminate
Leaf Base: Cuneate
Breeding System: Flowers Bisexual
Fruit Type: Capsule
Size Notes: Up to about 3 feet tall.
Leaf: Dark Green
Flower: Flowers 1.2 cm long
Fruit: Brown 12 mm

Bloom Information

Bloom Color: White , Pink , Purple , Violet
Bloom Time: Apr , May , Jun , Jul , Aug , Sep , Oct


USA: AL , AR , DC , DE , FL , GA , IA , IL , IN , KS , KY , LA , MD , MI , MO , MS , NC , NJ , NY , OH , OK , PA , SC , TN , TX , VA , VT , WV
Canada: ON , QC
Native Distribution: Ontario and Quebec; New York south to Florida, west to Texas, and north to Kansas, Iowa, Wisconsin, and Michigan.
Native Habitat: Grows in water, moist soil, and mud in east and southeast Texas, on the Edwards Plateau, and in north central Texas. Sand, loam, clay, mud. Poor drainage okay.

Growing Conditions

Water Use: Medium
Light Requirement: Sun , Part Shade
Soil Moisture: Moist , Wet
CaCO3 Tolerance: Medium
Soil Description: Sandy, Sandy Loam Medium Loam, Clay Loam, Clay
Conditions Comments: American water-willow blooms throughout the summer and colonizes by underground stems. It will grow in moist soil or submerged in a few feet of water. Larval food plant for the Texan Crescentspot butterfly. Good for wetland gardens and habitat.


Use Ornamental: Water garden
Conspicuous Flowers: yes
Attracts: Butterflies
Larval Host: Texan Crescentspot butterfly
Deer Resistant: Minimal


Commercially Avail: yes

National Wetland Indicator Status

This information is derived from the U.S. Army Corps of Engineers National Wetland Plant List, Version 3.1 (Lichvar, R.W. 2013. The National Wetland Plant List: 2013 wetland ratings. Phytoneuron 2013-49: 1-241). Click here for map of regions.

From the National Organizations Directory

According to the species list provided by Affiliate Organizations, this plant is on display at the following locations:

Fredericksburg Nature Center - Fredericksburg, TX
Lady Bird Johnson Wildflower Center - Austin, TX
Delaware Nature Society - Hockessin, DE
Nueces River Authority - Uvalde, TX
Jacob's Well Natural Area - Wimberley, TX
Mt. Cuba Center - Hockessin, DE


Bibref 328 - Wildflowers of Texas (2003) Ajilvsgi, Geyata.
Bibref 286 - Wildflowers of the Texas Hill Country (1989) Enquist, M.

Search More Titles in Bibliography

Web Reference

Webref 23 - Southwest Environmental Information Network (2009) SEINet - Arizona Chapter

Additional resources

USDA: Find Justicia americana in USDA Plants
FNA: Find Justicia americana in the Flora of North America (if available)
Google: Search Google for Justicia americana


Record Modified: 2023-02-15
Research By: TWC Staff, JSC

Go back