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Giant Salvinia - Invasive Species Information

High Risk

Reproduction: Reproduces by asexual reproduction only, but it is capable of growing extremely quickly, starting from small fragments and doubling in dry weight every 2.2–2.5 days. Giant Salvinia grows from fragments that have broken off or dormant buds that have been detached from the main plant.

 

Each node has five buds so potential for rapid spread is high. It also produces spores which are genetically defective and do not produce viable offspring.

Giant Silvania Stand

Giant Silvania Stand

Giant Salvinia Leaves

Giant Salvinia is an aquatic fern, native to south-eastern Brazil. It is a free floating plant that does not attach to the soil, but instead remains buoyant on the surface of a body of water. Fonds are used to provide a waterproof covering. These fronds are produced in pairs also with a third modified root-like frond that hangs in the water.

How To Identify Giant Salvinia?

Colour: Large green leaf. Fronds are 0.5–4 cm long and broad, with a bristly surface caused by the hair-like strands that join at the end to form eggbeater shapes.

Size: Can grow up to 1.5 metre 

Giant Silvania Floating
Giant Salvinia Leaves
Giant Salvinia Spores
Giant Salvinia Hairs Close-up
Giant Salvinia - Salvinia molesta ID Guide

Giant Silvania Leaves

Giant Silvania - Salvinia molesta ID Guide

Floating

Spores

Leaf Hairs

Why Is Giant Salvinia A Problem?

The dense mats fill in water-bodies resulting in decreases in density and diversity of native aquatic plants and animals. Similarly, giant salvinia mats can affect crop production, access to waterways for humans and livestock.

Giant Silvania Leaves

What Is Giant Salvinia - (Salvinia molesta)?

Habitat: Aquatic, fresh water
Distribution in Ireland: Sparse distribution but locally abundant in some places.

Status: Established
Family name: Menyanthaceae

European Communities (Birds and Natural Habitats) Regulations 2011 non-native invasive plant species A-Z (Updated 2017)

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There are currently 35 invasive plant species listed in the European Communities (Birds and Natural Habitats) Regulations (annex 2, Part 1)...

 

Click on a species from the following list to find out more regarding non-native species subject to restrictions under Regulations 49 and 50.

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  1. American Skunk-Cabbage - Lysichiton americanus

  2. Brazilian Giant-Rhubarb - Gunnera manicata

  3. Broad-Leaved Rush - Juncus planifolius

  4. Cape Pondweed - Aponogeton distachyos

  5. Cord-Grasses - Spartina (all species and hybrids)

  6. Curly Waterweed - Lagarosiphon major

  7. Dwarf Eel-Grass - Zostera japonica

  8. Fanwort - Cabomba caroliniana

  9. Floating Pennywort - Hydrocotyle ranunculoides

  10. Fringed Water-Lily - Nymphoides peltata

  11. Giant Hogweed - Heracleum mantegazzianum

  12. Giant Knotweed - Fallopia sachalinensis

  13. Giant-Rhubarb - Gunnera tinctoria

  14. Giant Salvinia - Salvinia molesta

  15. Himalayan Balsam - Impatiens glandulifera

  16. Himalayan Knotweed - Persicaria wallichii

  17. Hottentot-Fig - Carpobrotus edulis

  18. Japanese Knotweed - Fallopia japonica

  19. Large-Flowered Waterweed - Egeria densa

  20. Mile-a-Minute Weed - Persicaria perfoliata

  21. New Zealand Pigmyweed - Crassula helmsii

  22. Parrots Feather - Myriophyllum aquaticum

  23. Red Alga - Grateloupia doryphora

  24. Rhododendron - Rhododendron ponticum

  25. Salmonberry - Rubus spectabilis

  26. Sea-Buckthorn - Hippophae rhamnoides

  27. Spanish Bluebell - Hyacinthoides hispanica

  28. Three-Cornered Leek - Allium triquetrum

  29. Wakame - Undaria pinnatifida

  30. Water Chestnut - Trapa natans

  31. Water Fern - Azolla filiculoides

  32. Water Lettuce - Pistia stratiotes

  33. Water-Primrose - Ludwigia (all species)

  34. Waterweeds - Elodea (all species)

  35. Wireweed - Sargassum muticum

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