Nature of the Lake: American Water-willow

American Water-willow is an overlooked lakeside beauty. Photo courtesy of Kenneth Boone.

If you have lakefront property, there’s a good chance you have spectacular, orchid-like wildflowers in your “front yard.” But you may not know it because these exquisite blossoms are tiny, and they’re not where you’d expect to find such a showpiece.

American Water-willow is a common perennial aquatic plant native to Alabama and most of the central and eastern United States. The plant’s range covers the south from Texas to Florida and extends through the central and eastern states and all the way north into Canada.

Although its common name doesn’t sound all that patriotic, its scientific name sure does: Justicia americana. But in this case, Justicia americana doesn’t refer to the American court system. In fact, the flower was identified in 1753, before there was a United States of America. Instead, Justicia americana was named after the Scottish horticulturist James Justice who lived from 1698 to 1763.

American Water-willow is common and prolific on the creeks and rivers in our part of Alabama, like Hatchett and Hillabee creeks and the Coosa and Tallapoosa rivers. It also grows wild around the edges of most slower-moving water in our area, including Lake Martin.

American Water-willow is a small green plant that forms dense colonies in shallow water. From a distance, it looks like an average shore plant – nothing special.

This plant grows to 3 feet tall and is often found on the waterline or slightly offshore in lakes, or in shallow riffles and around islands in the middle of creeks and rivers. Its “feet” are usually wet while the upper stem, leaves and blossoms are usually out of the water. Although their blossoms look delicate, American Water-willow is a tough plant that is able to survive and thrive when submerged in the washing-machine action of floodwaters that sweep Alabama’s rivers from time to time.

The green stems of the water-willow are usually straight without branches and have whitish vertical lines along the stem and whitish nodes where the leaves connect the stem.

Leaves are long and slender with a lighter colored vein along the center. Water-willow leaves grow up to 6 inches long, and they look a lot like a willow tree’s leaves, which makes perfect sense given this plant’s common name. A series of paired leaves grow opposite each other along the stem.

The flower of the American Water-willow is its crowning glory. Although these blossoms are very small – less than an inch across – a quick, close-up look with a magnifying glass will delight orchid lovers.

The give-petal flower is white, with pink, red, purple or violet colors. Blooms are found from April to October across its range, according to the Lady Bird Johnson Wildflower Center. These blossoms were photographed on May 18 on Russell Pond, a man-made lake on the Lake Martin tributary, Elkahatchee Creek. The flowers all had white petals with pastel purple tips on the upper leaves, deep purple stripes on the lower petals and dark purple anthers with large white filaments.

Multiple American Water-willow blossoms form on the ends of spikes and usually emerge in pairs on opposite sides of the same spike.

The magnificent flowers look a whole lot like the commercially grown phalaenopsis orchids for sale in nurseries and upscale grocery stores, only the blossoms are much smaller. A large water-willow blossom measures three-quarters of an inch in diameter.

A related species is also native to Alabama, Justicia ovate, which has more loosely flowered spikes.

American Water-willow reproduces seeds that look like small brown capsules, but once a plant is established, it will also send out rhizomes, which allows it to form large, crowded plant colonies.

This is a plant that functions like the mangroves in the southern Florida coastlines; its closely spaced stems in shallow water provide a protective “forest” for small aquatic animals, which in turn attracts predatory fish, ducks, amphibians and other larger animals in search of meals. In other words, a colony of American Water-willows can serve as an important fresh-water breeding ground for small fish and aquatic invertebrates that form the largest numbers of living animals in a local ecosystem. It’s also why, so often, the best fishing is along the shoreline of any body of water – that’s where the food is.

Water-willow themselves are consumed by plant-eaters. Aquatic rodents like beaver and muskrat eat water-willow rhizomes, and deer enjoy the opportunity to get a drink of water while they munch the leaves.

This plant’s flowers are cross-pollinated by a number of native bees and domesticated honeybees, as well as some butterflies, flies and wasps. Water-willow is a host plant for the caterpillars of the beautiful Hydrangea Sphinx moth.

Because it forms thick colonies at the water’s edge, American Water-willow plays an important role in reducing erosion on the banks of lakes and rivers.

So put on your swimsuit, pick up a magnifying glass, walk down to the shoreline and take a moment to appreciate the wild, natural beauty of the American Water-willow, a magnificent, useful and usually overlooked plant growing wild all around Lake Martin.

Some information for this article came from the Texas A&M AgriLife Extension website www.aquaplant.tamu.edu and the Ladybird Johnson Wildflower Center site www.wildflower.org.