Skip to main content

American water-willow

Justicia americana (L.) Vahl

Images

Click on image to view full size

American water-willow
American water-willow leaves
American water-willow fruit
American water-willow
American water-willow
American water-willow
American water-willow
American water-willow flowers

Morphology

Stem
Erect, simple or branched, glabrous; rhizomes branched, cord-like, producing numerous stems rising to various heights according to water depth.
Leaves
Cauline, opposite, simple; petiole 0 to .4 inch, glabrous; blade narrowly elliptic to ovate-elliptic, 1.6 to 5.5 inches long, .3 to 1 inch wide, base tapered, margins entire or obscurely wavy, tip obtuse to acute.
Inflorescence
Axillary spikes, 10-30-flowered, .6 to 1.2 inch; peduncles 1.6 to 6.7 inches; bracts not leaf-like, triangular.
Flower
Calyx .2 to .25 inch, lobes (4-)5, linear-lanceolate to subulate; corolla white to pale violet or lilac and lower lip sometimes with darker spots, .25 to .6 inch, two-lipped, lower lip spreading, 3-lobed, upper lip spreading to reflexed; stamens 2, exserted.
Fruit
Capsules clavate or cylindric, not flattened, stipitate, .3 to .7 inch long, .08 to .14 inch wide; seeds 4, brownish, round, flattened, .08 to .14 inch, covered with minute, wart-like bumps.

Ecology

Habitat
Shallow water, muddy or gravelly shorelines, and gravel bars.
Distribution
East 1/2 of Kansas

Additional Notes

Comments

Named for James Justice, 18th century Scotch horticulturist and botanist. Horizontal rhizomes grow from bases of leaf-bearing stems. The following spring, terminal buds of these rhizomes produce upright shoots with adventitious roots at their bases. These shoots begin blooming in June, and new horizontal rhizomes arise at their bases. Older parts die by the end of the second year. The interlaced network of radiating rhizomes protects plants from erosion.

Quick Facts
Plant Type
Wildflower
Family
Acanthaceae - Acanthus Family
Life Span
Perennial
Height
20-40 inches
Origin
Native
Last Updated
2014-01-18
Color Groups
Blue, Purple, Lavender & Violet Wildflowers
White, Green & Greenish White Wildflowers
Flowering Period
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Blooms: June, July, August