smooth cordgrass
Spartina alterniflora Loisel.


Spartina alterniflora is a perennial grass that expands via underground rhizomes. It is native to the eastern United States, but is considered invasive, in salt marshes, in California. Hollow stems grow from 2-4 ft. (0.6-1.2 m) tall.
Leaves are 8-20 in. (20-50 cm) long, 1-8 in. (2.5-20 cm) wide and are often purplish at the base.
Flowering occurs in July to November, when densely packed clusters of tan flowers develop.
The fruit are flattened and smooth, with pointed tips. The plant also expands via underground rhizomes.
Ecological Threat
Spartina alterniflora was introduced on the west coast in the early 1970s to be used as erosion control. Plants have become extremely invasive in San Francisco Bay, Willapa Bay and Puget Sound.


Selected Images


EDDMapS Distribution

EDDMapS Distribution - This map is incomplete and is based only on current site and county level reports made by experts, herbaria, and literature. For more information, visit

State Regulated List

State Regulated List - This map identifies those states that list this species on their regulated list. For more information, visit

Taxonomic Rank

Kingdom: Plantae
Phylum: Magnoliophyta
Class: Liliopsida
Subclass: Commelinidae
Order: Cyperales
Family: Poaceae
Genus: Spartina
Subject: Spartina alterniflora Loisel.

Synonyms and Other Names

Other Common Names:
Atlantic cordgrass, saltmarsh cordgrass


Plants - Grass or Grasslike