Kariba weed

Salvinia molesta
Kariba weed: Salvinia molesta Kariba weed: Salvinia molesta

Common name:

Kariba weed

Scientific name:

Salvinia molesta (Salviniaceae)

Alternative common names:

Salvinia, African pyle, water fern (English); watervaring (Afrikaans)

An aquatic, mat-forming, free-floating fern with horizontal stems up to 25cm long. Green to yellow-green oval leaves form in pairs with dense upper surface cover of hairs. Feathery, root-like leaves hang down in the water

Additional Info

  • Where does this species come from?

    Brazil in South America

    What is its invasive status in South Africa?

    Existing legislation: CARA 2002 – Category 1 NEMBA Category 1b

    Where in South Africa is it a problem?

    Western and Eastern Cape, KwaZulu-Natal, Gauteng, Mpumalanga and Limpopo

    How does it spread?

    Spreads only vegetatively by fragmentation

    Why is it a problem?

    Forms dense mats up to 50 cm thick which completely cover a water surface. The mats clog waterways and irrigation equipment, reduce waterflow, impede navigation, fishing and other recreational activities, provide a breeding place for mosquitoes and bilharzia-carrying snails. Dense mats reduce light penetration, reduce oxygen levels and result in poor water quality. Dense mats threaten indigenous aquatic plant and animal life

    What does it look like?

    General description: A green, mat-forming water weed with leaves covered in dense hairs. Leaves: Green to yellow-green oval leaves in pairs with dense upper surface cover of hairs Flowers: None Fruit/seeds: None

    Does the plant have any uses?

    Ornament