Glyceria declinata

Photo courtesy Joseph DiTomaso

Common names: mannagrass; sweetgrass; waxy mannagrass

Glyceria declinata (waxy mannagrass) is a perennial grass (family Poaceae). Waxy mannagrass is found in the Central Valley, from Shasta County south to Fresno County. It has invaded deep vernal pools, swales, ditches, and stock ponds. Some reports indicate that it is rapidly spreading in Central Valley vernal pools.

Cal-IPC Rating: Moderate

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 RIC 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

There are no newsletter articles associated with this species yet.

Cal-IPC Symposium Presentations

Other Glyceria declinata Information

  • CalPhotos - Images of plants taken mostly in California.
  • Calflora - See the distribution of this species on Calflora's map of California.
  • CalWeedMapper - Distribution information with ability to determine regional priorities.
  • 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.
  • Bugwood - National database from the Center for Invasive Species and Ecosystem Health at the University of Georgia.