Rooted-Floating Aquatics

This tool lists various Habitat Fact Sheets developed by the Region 5 Regional Response Team. To suggest additions to this tool, please contact Barbi Lee. Click here for Inland Response Tactics Manual.

Water lilies in emergent marsh
Rooted floating aquatic plants such as the water lily Nymphaea spp. often occur alongside emergent vegetation.

Image Credit: Kate Redmond, Courtesy of the Wisconsin Bird Conservation Initiative
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White Water Lily Nymphaea odorata
The white water lily is one of the most common rooted floating aquatic perennials in the United States. It grows rooted in mud or silt bottoms in up to 5 feet of water. Each plant consists of one emergent white flower with a yellow center, surrounded by floating round leaves ranging from 6-12 inches in diameter. The leaves are predominately green but may contain patches of yellow. The plant reproduces by seed but also through rhizomes, which can result in the proliferation of dense mats in open water or disturbed areas.

Image Credit: William S. Justice, Courtesy of the Smithsonian Institution
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Bed of white water lilies
Water lilies often occur as dense beds in mucky or silty bottom water bodies up to 5 feet deep.

Image Credit: Maine Department of Agriculture, Conservation and Forestry
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Spatterdock Nuphar spp.
Spatterdock bed rooted in open water.

Image Credit: Roberta Hill, VLMP
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Spatterdock Nuphar spp.
Though technically an emergent aquatic plant as its leaves can be several inches above the water's surface, spatterdock leaves commonly float. Like the white water lily, spatterdock grows on mud or silty bottoms in 1-5 feet of water. The green leaves are heart-shaped, ranging from 6-12 inches in diameter and can be mistaken for arrowhead when emergent. The leaves surround a small bulbous, yellow flower spanning 1-3 inches across. The perennial plant produces by seed and through rhizomes, which can result in dense colonies.

Image Credit: Dr. John Hilty, Illinois Wildflowers
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Nonnative Water Lily Nymphaea spp.
Invasive and nonnative water lilies tend to have bright pink, purple, or red flowers.

Image Credit: State of Washington Department of Ecology
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American Lotus Colony
American Lotus Nelumbo lutea are common in backwater areas subject to high flooding.

Image Credit: Peter M. Dziuk, MinnesotaWildflowers.info
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American Lotus Flower
The American Lotus has a single pale yellow flower 4-10 inches in diameter rising up to 3 feet above the water on a bare stalk. The large petals are arranged around a spongy receptacle which houses the reproductive organs and eventually the fruits. The blooming period occurs in late spring in the southern range of its habitat and from July to September in northern extents.

Image Credit: W.S. Justice, courtesy of the Smithsonian Institution
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American Lotus Leaves
American Lotus leaves are 12-18 inches across, deep green, and can rise a foot or more above the water.

Image Credit: Peter M. Dzuik, MinnesotaWildflowers.info
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I. Habitat Description

Rooted-Floating Aquatics (RFA) represent portions of lakes, ponds, marshes, backwaters, or channel borders that are >10% vegetated with water lilies (Nymphaea and Nuphar) or American Lotus (Nelumbo). This general class is dominated by rooted-floating aquatics, but may have inclusions of submersed, nonrooted-floating aquatics, or emergent vegetation. It is typically found growing between water depths of 0.25 and 2 m. This general class remains permanently flooded all year.

II. Sensitivity to Oil Spills

Due to proximity to shorelines and establishment in shallow water, the rooted floating aquatics habitat is highly sensitive to oil spills. Floating vegetation provides cover for several species of amphibians and fish. It is also important habitat for invertebrates. Many fish, invertebrates, and amphibious species deposit eggs on rooted floating vegetation. Light refined oils with high amounts of water-soluble fractions can cause acute mortality to animals and plants in these shallow habitats. Heavier oils tend to coat vegetation and animals, though the vegetation may survive because the roots are not affected. It is more difficult for more viscous oils to penetrate dense vegetation beds. However, these oils can smother water lily beds. Above all, oil reduces plant and animal tolerance to other environmental stress factors.

III. Sensitivity to Response Methods

Relevant response tactics are ordered below by least-to-most adverse habitat impact. Bullet points list quick-reference information regarding the tactic; any potential adverse impacts of its use; and suggestions for mitigation of these impacts if available. This is not intended to preclude the use of any particular tactic, but rather to aid responders in choosing the tactic(s) best suited to a specific habitat. For more information on a tactic, click on it or go to the corresponding section in the Inland Response Tactics Manual.