Photo credit: Fred Weinmann, Bugwood.org
Synonyms
Saltwater cordgrass, saltmarsh cordgrass, Atlantic cordgrass
ID Characteristics
General: Smooth cordgrass is a perennial grass that grows 0.5 – 3m tall and forms extensive monoculture meadows.
Flowers: The yellow-white inconspicuous flowers are 2 – 5 cm long.
Stems: Stems are soft, spongy. hollow and hairless. They grow up to 1.2 cm in diameter.
Leaves: The flat leaf blades are up to 50 cm long, and 3 to 25mm wide. The leaves have ligules that consist of a fringe of hairs.
Seeds: The 25 – 30 cm long seedheads emerge at the end of the stem.
Roots: Dense rhizome system that binds in coastal mud.
Similar Species
-
Invasive:
English cordgrass (Spartina anglica) has distinctive 45-90 degree angle to stems, and doesn’t grow as tall as smooth cordgrass (up to 1.5 m).
Photo credit: G. Williams
Saltmeadow cordgrass (Spartina patens) is another invasive plant that resembles smooth cordgrass, but doesn’t grow as tall (up to 1.2 m tall) and has reddish inflorescences (flowerheads).
Photo credit: J. Fenneman
Habitat and Origin
Smooth cordgrass is native to the Atlantic and Gulf coastlines of North America. It has been intentionally planted on the West Coast of North America, along as in the UK, Northern Europe, New Zealand, and China due to its ability to assist in erosion control.
Smooth cordgrass is found in the intertidal zone. It can grow in a variety of substrates, from sand and silt to loose cobbles, clay and gravels. It can also grow in sandy aerobic or anaerobic soils with a range of acidities. It is mainly found in mudflats, brackish waters and lagoons.
How it Spreads
Smooth cordgrass spreads both vegetatively and by seed. Its seeds are pollinated in the wind; this plant can produce up to 80,000 seeds per kg of plant matter.
Humans play a significant role in its spread, as plant fragments can be accidentally transported via ship ballast water or intentionally introduced for erosion control.
Impacts
Ecological:
- Forms dense monocultures, displacing native flora and fauna.
- The higher stem densities dissipate wave action. This reduces tidal energy and traps sediment, fundamentally changing the nature of some coastlines, leading to the formation of steeper beach profiles.
- Can alter water circulation patterns.
Economic:
- Negatively impacts coastal-based industries, such as tourism.
- Soil accretion affects navigation and can cause flooding.
Prevent the Spread
Smooth cordgrass is NOT currently found in the Sea to Sky Corridor, so the best approach to controlling its spread is by PREVENTION.
This is a high-priority invasive species for the Province of BC, and it is included in the Early Detection and Rapid Response (EDRR) program.
If you see smooth cordgrass, please report it.
Sea to Sky Distribution
Smooth Cordgrass Factsheet
Having trouble viewing the factsheet? Don’t worry, all the information is included on this page. You can also contact us with any questions.
