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Native Plant Society of Texas

Water Willow

Justicia americana

Other common name(s):

American Water-willow

Family:

Acanthaceae (Acanthus Family)

Plant Ecoregion Distribution Map

This map uses data from the US EPA. EPA  servers have been offline frequently so maps may not display. We are working on a solution.

Cross Timbers, Edwards Plateau, Southern Texas Plains, Texas Blackland Prairies
Carbonate Cross Timbers, Eastern Cross Timbers, Grand Prairie, Limestone Cut Plain, Western Cross Timbers
Balcones Canyonlands, Edwards Plateau Woodland, Llano Uplift, Semiarid Edwards Plateau
Northern Nueces Alluvial Plains, Rio Grande Floodplain and Terraces, Semiarid Edwards Bajada
Floodplains and Low Terraces1, Northern Blackland Prairie, Southern Blackland Prairie

Plant Characteristics

Growth Form

Herbaceous, Wetland

Height

1
to
3
ft.

Spread

1
to
3
ft.

Leaf Retention

Deciduous

Lifespan

Perennial

Habitat and Care Requirements

Soil Type(s)

Moist, Mud, Poor Drainage

Light Requirement

Sun, Part Shade

Water Requirement

Medium

Native Habitat

Riparian, Wetland

Bloom and Attraction

Bloom Color

Blue, Pink, Purple, White

Bloom Season

Spring, Summer, Fall

Seasonal Interest

Larval Host, Nectar

Wildlife Benefit

Aquatic Wildlife, Butterflies

Maintenance

Good for water gardens. Forms large colonies by underground stems. Thin if needed to fit the space. Set up a pond or a water collection tank near a downspout to supplement water. Often is found growing in shallow water depths, 2-4 inches, but can grow in depths of 4-plus feet. Native habitat: near streams, rivers and creeks, ponds and lakes.

Description

Blooms April-October. Stems are smooth, unbranched, and slightly ribbed. Lance-shaped leaves taper at the end. White flowers with a purple lip are clustered in spikes on stalks that arise from axils of upper leaves. The fruit is a small brown capsule. Rhizomes and roots provide spawning sites for many fish species and habitat for invertebrates. Larval host: Texas Crescentspot Butterfly.
Previous Scientific Name(s): Dianthera americana, Dianthera americana var. subcoriacea, Justicia americana var. subcoriacea, Justicia mortuifluminis, Justicia umbratilis

References

Learn about how to propagate Texas native plants.

Material Treatment Method Collection References
Root Division Divide and transplant in another area or in a pot. Experience from NPSOT Austin member, Claire Sorenson.
Seed No Treatment Sow seeds in the spring. Peat pots provide an ideal environment for american water-willow seedlings, promoting healthy root development. Peat pots can be planted directly into the soil, reducing root disturbance. This feature is crucial for american water-willow, which may have delicate root systems that could be damaged during transplanting. Spread the seeds evenly across the surface of the prepared soil. Lightly press the seeds into the soil but do not bury them deeply, as they require light to germinate effectively. Cover the seed trays with a clear plastic lid or wrap to maintain a high humidity environment. Place in indirect sunlight and ensure the soil remains consistently moist. https://www.picturethisai.com/care/propagate/Justicia_americana.html
Stem Cutting Remove the lower leaves and dip the bottom of the stem in rooting hormone. Plant the cutting in a container filled with moist potting soil and cover with a plastic bag or dome. Place the container in a well-lit area, but avoid direct sunlight. Take a stem cutting in spring or summer that is at least 6 inches long and has 2-4 nodes 1) https://plantiary.com/plant/justicia-americana_12002.html 2) https://www.botanikks.com/plants/justicia-americana-l-vahl/517769/1

About the Region

2026 Fall Symposium Logo

This low-elevations region of Texas extends inland from the barrier islands, about 60 or so miles, and stretches from Brownsville to Louisiana. In total, it covers about 9.5 million acres, with a high point of 150 feet in elevation. More than 1000 species of plants can be found in this region. On the southern end, species more common in Mexico (such as Sabal mexicana) and Central America occur.

The barrier islands provide us with dune systems, and clay flats to the inland side, which have species found in these areas alone. Many plants here, such as Ipomoea pes-caprae (beach morning glory), can be found throughout tropical regions of the globe. I’ve encountered the same species on the beaches of Guam.

Once inland, vast marshes and wet prairies occur. Occasionally, oak (Quercus fusiformis) groves can be found. Common grasses include species of Bothriochloa, Paspalum, and Sporobolus; eastern gamagrass (Tripsacum dactyloides); and switchgrass (Panicum species). Many rivers and creeks cut through the Gulf Prairies, and along these riparian areas various species of trees, Sabal minor, and other plants adapted to clay soils can be found. Due to overgrazing, farming, and fire suppression, woody species such as mesquite (Prosopis glandulosa) and huisache (Acacia farnesiana), and invasive species such as chinaberry (Melia azedarach), Brazilian pepper (Schinus terebinthifolius), and Chinese tallow (Sapium sebiferum) have increased and displaced our native flora.

Source: Wildflowers of Texas by Michael Eason