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Oxygen Weed

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Oxygen weed
Scientific Name:

Lagarosiphon major (Ridley) Moss (ITIS)

Common Name:

Oxygen weed, Lagarosiphon, African elodea, curly waterweed

Oxgen weed - Photo by Rohan Wells; National Institute of Water and Atmospheric Research
Native To:

Southern Africa (McGregor and Gourlay 2002)

Date of U.S. Introduction:

Not introduced

Means of Introduction:

Spread throughout the world as an aquarium plant (National Heritage Trust 2003)


Has invaded New Zealand and Europe. It can inhabit freshwater lakes, dams and slow moving streams. Forms dense mats that block sunlight, thereby killing native aquatic plant and animal species, which could rival the harmful effects of hydrilla (Csurhes and Edwards 1998)

Current U.S. Distribution:

Not currently established

Federally Regulated

  • USDA. APHIS. Plant Protection and Quarantine.

    Includes species listed as a Federal Noxious Weed under the Plant Protection Act, which makes it illegal in the U.S. to import or transport between States without a permit.



  • Google. YouTube; RTÉ Ireland. Eco Eye.

    This beautiful episode opens on Lough Corrib at sunrise. Anja sees first-hand the devastating and costly impacts of a new arrival to an existing ecosystem, Lagarosiphon Major a pond weed has taken hold in the waterbody. Part 1 of 4

Selected Resources

The section below contains highly relevant resources for this species, organized by source. Or, to display all related content view all resources for Oxygen Weed.


IUCN. Species Survival Commission. Invasive Species Specialist Group.

International Government

Australian Government. Department of the Environment and Energy.


University of Florida. IFAS. Center for Aquatic and Invasive Plants.