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
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
Plant CharacteristicsDuration: Perennial
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 InformationBloom Color: White , Pink , Purple , Violet
Bloom Time: Apr , May , Jun , Jul , Aug , Sep , Oct
DistributionUSA: 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 ConditionsWater 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.
BenefitUse Ornamental: Water garden
Conspicuous Flowers: yes
Larval Host: Texan Crescentspot butterfly
Deer Resistant: Minimal
PropagationCommercially Avail: yes
National Wetland Indicator Status
From the National Organizations DirectoryAccording 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
BibliographyBibref 328 - Wildflowers of Texas (2003) Ajilvsgi, Geyata.
Bibref 286 - Wildflowers of the Texas Hill Country (1989) Enquist, M.
Search More Titles in Bibliography
Web ReferenceWebref 23 - Southwest Environmental Information Network (2009) SEINet - Arizona Chapter
Additional resourcesUSDA: Find Justicia americana in USDA Plants
FNA: Find Justicia americana in the Flora of North America (if available)
Google: Search Google for Justicia americana
MetadataRecord Modified: 2023-02-15
Research By: TWC Staff, JSC