Water Stargrass
Heteranthera dubia
Water stargrass is an underwater grass with long, grass-like leaves and distinctive yellow, star-like flowers along freely branching stems. It grows in the fresh waters of the upper Chesapeake Bay and tributaries throughout the Bay watershed.

Appearance
Water stargrass is made up of long, grass-like leaves that grow alternately along freely branching stems. The base of each leaf wraps around the stem. In summer, small, yellow, six-petaled flowers project above the water’s surface.
Reproduction and Life Cycle
Asexual reproduction occurs when stem fragments break off and overwinter at the bottom before growing into a new plant in spring. Sexual reproduction takes place in summer when the plant flowers.
Seeds form in late summer and autumn, then grow into new plants in the spring.
Did You Know?
- Water stargrass gets its name from its yellow flowers, which look like tiny stars floating above the water.
- If it washes ashore, water stargrass can grow on land. The land-growing form has smaller leathery leaves and very few branches, but still produces the characteristic star-like flowers.
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
- SAV Key: Water Stargrass – Maryland Department of Natural Resources