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Giant salvinia (Salvinia molesta)

Giant salvinia Synonyms: Salvinia auriculata, Salvinia biloba, Salvinia herzogii

Common Names: Kariba weed, Water fern, Aquarium watermoss

Description: This species is listed on the Federal Noxious Weed list and on the Michigan prohibited aquatic plant list.

Habit: Free-floating, mat forming water fern; mats may be up to 0.9 m (3 ft) thick; Believed to be sterile in US.

Leaves: At each node is a pair of emergent or floating leaf-like green fronds and one brown feather-like frond handing below, resembling roots; densely packed into chains as they grow, covered with tiny hairs that split and then rejoin at their tips.

Stems: Delicate.

Flowers: Non-flowering.

Fruit and seeds: A nutlike sporocarp (a multicellular structure), trailing beneath.

Habitat: Native to Brazil. Found in lakes, ponds, ditches and slow moving waters; intolerant of brackish water.

Reproduction: Vegetatively, dispersed by waterfowl, boats.

Similar species: Water spangles (Salvinia minima).

Monitoring and rapid response: Hand-pulling, followed by plants being dried or burnt and disposed of.

Credits: The information provided in this factsheet was gathered from the Michigan Natural Features Inventory and the University of Florida Institute of Food and Agricultural Sciences.

Individual species images that appear with a number in a black box are courtesy of the network ( photo author credits may not be included due to the small display size of the images and subsequent difficulty of reading the provided text. All other images appear courtesy of Google (

Common Name:

Giant salvinia

Scientific Name:

Salvinia molesta


(Floating fern)


Annual, Perennial



USDA Symbol:


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