Redhead Grass
Potamogeton perfoliatus
Redhead grass, a type of underwater grass or submerged aquatic vegetation (SAV), grows at Round Bay on the Severn River in Anne Arundel County, Md., on Aug. 26, 2019. (Photo by Will Parson/Chesapeake Bay Program)
Redhead grass grows in fresh to moderately brackish tidal waters that have a slow current and a firm, muddy bottom. (Maryland Department of Natural Resources)
Redhead grass has broad, oval leaves that grow alternately along slender stems. (Maryland Department of Natural Resources)
Redhead grass is a bay grass with flat, oval leaves that wrap around the base of straight, slender stems. It grows in fresh to moderately brackish tidal waters in the Maryland portion of the Chesapeake Bay watershed.
Appearance
Redhead grass is made up of straight, slender stems that are reddish or whitish and flat, oval leaves with curled edges and visible veins. Leaves grow in an alternate or slightly opposite pattern. The base of the leaves wrap around the stem. Spikes of tiny flowers that poke above the water’s surface in early-mid summer. Redhead grass has an extensive root and rhizome system.
Predators
Migratory waterfowl feed on redhead grass.
Reproduction and Life Cycle
Reproduces sexually in early-mid summer when flowers are pollinated and the plants produce dark-colored fruits that contain seeds. The fruits eventually mature and sink to the bottom, releasing the seeds. Reproduces asexually when buds that develop over the summer produce shoots the following spring.
Did You Know?
- Redhead grass is probably named after the redhead, a duck that was once a common winter visitor to the Bay region. It is also known as clasping leaf pondweed.
- Young shoots of redhead grass can be confused with curly pondweed.
Sources and Additional Information
- Underwater Grasses in Chesapeake Bay & Mid-Atlantic Coastal Waters by Maryland Sea Grant
- Life in the Chesapeake Bay by Alice Jane Lippson and Robert L. Lippson
- Chesapeake Bay: Nature of the Estuary, A Field Guide by Christopher P. White
- Bay Grass Key: Redhead Grass – Maryland Department of Natural Resources
- PLANTS Database: Potamogeton perfoliatus – USDA Natural Resources Conservation Service
Quick Facts
Species
Native
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Habitat
Grows in fresh to moderately brackish tidal waters that have a slow current and a firm, muddy bottom.
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Range
Found in the upper to middle Chesapeake Bay and in many Maryland rivers; not recently documented in Virginia.
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Status
Stable