Zostera japonica

Photo courtesy: California Sea Grant

Synonyms: Nanozostera japonica (Asch. & Graebn.) P. Toml. & U. Posl.

Common names: dwarf eelgrass; Japanese eelgrass

Zostera japonica (=Nanozostera japonica, dwarf eelgrass) is an aquatic plant that forms dense stands in shallow, sheltered bays and estuaries. Populations of Z. japonica have been found in Humboldt County. Z. japonica often invades areas with little or no natural or human disturbance and also shows a positive relationship with disturbance. Z. japonica lives as an annual, overwintering as buried seeds, or a short-lived perennial. It reproduces vegetatively through rhizomatous cloning and sexually through seed production. The dispersal of the seeds, both within and between estuaries, may be aided by waterfowl species.  Z. japonica has been shown to rapidly expand in the spring and summer.

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

No Weed RIC Management Notes are available for this species. Check for information on other species in the genus on the Weed RIC site.

Cal-IPC Newsletter Articles

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Cal-IPC Symposium Presentations

  • None for this species

Other Zostera japonica Information

  • 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.