Get to Know Aquatic Plants

Get to Know Aquatic Plants: Lizard’s Tail and Water Willow

Aquatic plants enhance the health of lakes and rivers and have many positive effects for wildlife including absorbing excessive nutrients, stabilizing banks, and providing a healthy habitat and a food source for fish and other animals.

In our Paddle and Plants program, volunteers installed lizard’s tail and water willow along the banks of the Little Calumet River in 2021. This work is an extension of the successful plant installations Friends of the Chicago River has done since 2017 in the North Shore Channel of the river system in partnership with the Illinois Department of Natural Resources. The North Shore Channel starts in Wilmette and flows downstream through Evanston, Skokie, and Lincolnwood to the North Branch of the Chicago River at Foster Avenue in Chicago. The plant installations continue with the Shedd Aquarium. Over time both of these plant species expand into lush colonies in the emergent zone of the river providing many benefits including areas for fish to locate food and rest, bank erosion control, and water quality improvement.

Lizard’s Tail (Saururus cernuus)

As an aquatic plant lizard’s tail is an important food source for many animals, including beavers. It is highly deer resistant, which helps established lizard tail colonies in areas such as the Forest Preserves of Cook County, which have a high population of white-tailed deer. The foliage is rarely bothered by disease or insect pests. The plant attracts many invertebrates, which are an important food source for birds and fish.

Lizard’s tail is a perennial plant that grows up to three feet tall. It enjoys full sun to partial shade. Lizard’s Tail has shallow rhizomes that spread out and turn upward every 1 to 2 feet to produce new roots, forming colonies. The leaves of lizard’s tail are heart shaped, 3-6’ long on opposite branches. Lizard’s tail flowers are a defining feature of the plant, as they form a 4-7’ long semi-cylindrical shaped spike of dense whorls of tiny fragrant white flowers. They typically bloom June to September in the Chicago region (Illinois distribution map). The flowers then give way to small green fruits.

Water Willow (Justicia americana)

The water willow is also called the American water willow. The native water willow is occasional in most areas of Illinois, except the northwest region of the state, where it is uncommon (see distribution map). The water willow is shrub-like, but it is not woody perennial, with creeping rootstalks (rhizomes), often covering large areas along the edges of waterways. It enjoys full sun. Its flowers are clustered into head-like groups on stems arising from the upper branches; about ¾ inches long with a notched upper lip and a three-lobed lower lip. The upper lip is light purple, rarely white; the lower lip is white or pale purple with purple markings. Water willow blooms May to October.