Spartina alterniflora x S. foliosa

Photo courtesy Joseph DiTomaso

Common names: smooth hybrid cordgrass

Spartina alterniflora (and S. alterniflora x foliosa hybrids) (smooth cordgrass) is a rhizomatous perennial grass (family Poaceae) found in salt marshes and mudflats in the San Francisco Estuary and associated waterways. Smooth cordgrass spreads more rapidly, grows more densely, and tolerates higher water levels than native California cordgrass (Spartina foliosa). The two cordgrasses are known to hybridize, a process which may threaten the survival of pure strains of California cordgrass. A single smooth cordgrass plant may spread clonally in concentric circles to become a dense circular patch of up to 20 meters in diameter. The invasive cordgrass does not provide suitable habitat for native salt marsh shorebirds.

Cal-IPC Rating: High

CDFA Rating: B

Cal-IPC Assessment

Plant Assessment Form - Information gathered by Cal-IPC on the impacts, rate of spread, and distribution of invasive plants in California. Does not include management information.

Weed Management Notes

  • Management Notes - Information on management techniques and effectiveness from the University of California Cooperative Extension’s Weed Research & Information Center.

Cal-IPC Newsletter Articles

Cal-IPC Symposium Presentations

Presentations are linked where available. Where a presentation is not available, find more information by reading the abstract in the Cal-IPC Symposia Archive.

Other Spartina alterniflora x S. foliosa Information

  • CalPhotos - Images of plants taken mostly in California.
  • Calflora - See the distribution of this species on Calflora's map of California.
  • Jepson Online Interchange for California Flora - Information on taxonomy, biology, and distribution from UC Berkeley's Jepson Herbarium.
  • USDA PLANTS Database - Federal database with information on identification and distribution, and links to websites in individual states.
  • EDD MapS - North American distribution based on Early Detection and Distribution Mapping System.