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

Widgeon Grass

Ruppia maritima

Widgeon grass is a bay grass with delicate, thread-like leaves that grow alternately along slender, branching stems. It ranges from slightly brackish upper and middle Chesapeake Bay rivers to the saltier lower Bay.

Appearance:

Widgeon grass has delicate, thread-like leaves with rounded tips and a sheath at the base. Leaves grow alternately along slender, branching stems. The grass grows in two forms: an upright, branched form with flowers that stand several feet tall, and a short, creeping form with leaves at the base of the plant. In late summer, long stalks with clusters of individual black, pointed seeds grow from the base of the leaves. Widgeon grass has an extensive root system with creeping rhizomes that lack tubers.

Habitat:

Grows in a wide range of salinities, from slightly brackish (medium salinity) to salty waters (high salinity). Found in fresh water and non-tidal tributaries. Most common in shallow areas with a sandy bottom, but can also grow in soft, muddy sediments.

Range:

Ranges from the rivers of the upper and middle Chesapeake Bay to the saltier lower Bay. Widgeon grass and eelgrass are the dominant bay grass species in the Virginia portion of the Bay.

Predators:

Migratory waterfowl feed on widgeon grass.

Reproduction and Life Cycle:

Widgeon grass reproduces sexually between late spring and late summer when two flowers, which are enclosed in a sheath at the base of the leaves, emerge and grow on a stalk toward the water’s surface. Pollen floating on the water’s surface fertilizes the flowers, which then produce seeds. It can also reproduce asexually, when new stems grow from the plant’s root and rhizome system.

Other Facts:

• Widgeon grass is also known as ditch grass because it sometimes grows in ditches along road sides and farm fields.
• It can be confused with sago pondweed, slender pondweed and horned pondweed. Widgeon grass can be distinguished by its leaves, which grow alternately along the branches, and its seeds, which grow on individual stalks.

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: Widgeon Grass – Maryland Department of Natural Resources
• Species Inventory: Ruppia maritima – Smithsonian Marine Station at Fort Pierce
• PLANTS Database: Ruppia maritima – USDA Natural Resources Conservation Service

Places:

• Choptank and Tuckahoe Rivers Water Trail – Caroline and Talbot counties, Maryland
• Potomac River Water Trail – Washington, D.C. to Point Lookout, Maryland
• Virginia Eastern Shore Water Trails – Onancock and Saxis, Virginia
• Rappahannock River Water Trail – Fredericksburg, Virginia
• Mathews Blueways Water Trails – Mathews County, Virginia