• Bay 101
• Bay History
• The Bay Ecosystem
• Field Guide
• The Bay Watershed
• Bay FAQ
• Bay Glossary

Redhead Grass

Potamogeton perfoliatus

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.

Habitat:

Grows in fresh to moderately brackish tidal waters that have a slow current and a firm, muddy bottom.

Range:

Found in the upper to middle Chesapeake Bay and in many Maryland rivers; not recently documented in Virginia.

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.

Other Facts:

• 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

Places:

• Susquehanna River Water Trail – Lower Section – Harrisburg, Pennsylvania to Havre de Grace, Maryland